New particle foam

Abstract

The present invention relates to a method for preparing thermoplastic polyurethane, which comprises at least one isocyanate composition (ZI) reacting with a polyol composition (ZP) to obtain a prepolymer having isocyanate groups, and reacting the obtained prepolymer with at least one chain extender (KV), wherein the isocyanate composition comprises an isocyanate (l1) selected from the following: naphthylene 1,5-diisocyanate (NDI), diphenylmethane 4,4'-diisocyanate (MDI), p-phenylene diisocyanate (PPDI) and o-toluene diisocyanate (TODI), ethylene diphenyl diisocyanate (EDI) or a mixture thereof, and the polyol composition comprises polytetrahydrofuran or a derivative thereof. The present invention also relates to a thermoplastic polyurethane obtained or obtainable by the method of the type described, and an expanded granular material comprising the thermoplastic polyurethane. The present invention also relates to the use of the expanded granular material of the present invention for preparing molded articles.

Description

[0001] The present invention relates to a method for preparing thermoplastic polyurethane, which comprises at least converting at least one isocyanate composition (ZI) and a polyol composition (ZP) to obtain a prepolymer having isocyanate groups, and reacting the obtained prepolymer with at least one chain extender (KV), wherein the isocyanate composition comprises an isocyanate (l1) selected from the group consisting of naphthylene 1,5-diisocyanate (NDI), diphenylmethane 4,4'-diisocyanate (MDI), p-phenylene diisocyanate (PPDI) and o-toluene diisocyanate (TODI), ethylene diphenyl diisocyanate (EDI) or a mixture thereof, and the polyol composition comprises polytetrahydrofuran or a derivative thereof. The present invention also relates to a thermoplastic polyurethane obtained or obtainable by the method, and foam pellets comprising the thermoplastic polyurethane. The present invention also comprises the use of the foam pellets of the present invention for preparing molded articles.

[0002] Thermoplastic polyurethanes are known per se. Depending on the desired performance properties, the isocyanates, polyols and chain extenders used can be varied. Foam pellets based on thermoplastic polyurethane or other elastomers, which are also referred to as bead foams (or particle foams), and moldings produced therefrom are known per se (e.g., WO 94 / 20568, WO 2007 / 082838 A1, WO2017030835, WO 2013 / 153190 A1, WO2010010010) and have a wide variety of possible uses.

[0003] For the purposes of the present invention, "foam pellets" or "bead foam" or "particle foam" refers to beaded foams, wherein the average diameter of the beads is generally from 0.2 to 20 mm, preferably from 0.5 to 15 mm, and especially from 1 to 12 mm. For non-spherical beads, such as elongated or cylindrical beads, the diameter means the longest dimension.

[0004] In principle, there is a need for thermoplastic polyurethanes, in particular for foam pellets or bead foams, which have improved processing properties in order to provide corresponding moldings at minimum temperatures while retaining favorable mechanical properties. This is particularly important for the currently widely used fusion methods, in which the energy input for fusing the foam pellets is introduced via an auxiliary medium such as steam, since this achieves improved bonding and thus simultaneously reduces damage to the material or foam structure while achieving sufficient bonding or fusing.

[0005] In order to obtain favorable mechanical properties of the molded articles prepared from the foam pellets, sufficient bonding or fusion of the foam pellets is important. If the bonding or fusion of the foam beads is insufficient, their properties cannot be fully utilized and the overall mechanical properties of the resulting molded article are adversely affected. Similar considerations apply when the molded article is damaged. In such cases, the mechanical properties at the damaged point are unfavorable and the results are the same as above. Therefore, the properties of the polymers used must be effectively adjustable.

[0006] Known materials generally have a very low modulus of elasticity at room temperature, so for many applications a high density must be achieved in order to obtain sufficient stiffness or stability. At the same time, for many applications a high resilience and good mechanical properties need to be achieved, and the material needs to have good weldability in order to prepare moldings from the foam pellets.

[0007] In the context of the present invention, "favorable mechanical properties" should be interpreted in relation to the intended application. The most prominent application of the subject matter of the present invention is in the field of footwear, where the foam pellets can be used for moldings of structural parts of shoes where shock absorption and / or cushioning is important, such as midsoles and insoles.

[0008] Therefore, one object of the present invention is to provide thermoplastic polyurethanes and foam pellets based on thermoplastic polyurethanes, which have sufficient stiffness but at the same time good mechanical properties and good processing properties. Another object of the present invention is to provide a method for preparing the corresponding thermoplastic polyurethanes and foam pellets.

[0009] According to the present invention, this object is achieved by a method for preparing thermoplastic polyurethane, which method comprises at least steps (i) and (ii):

[0010] (i) converting at least one isocyanate composition (ZI) and a polyol composition (ZP) to obtain a prepolymer having isocyanate groups, the isocyanate composition comprising an isocyanate (l1) selected from the group consisting of naphthylene 1,5-diisocyanate (NDI), diphenylmethane 4,4'-diisocyanate (MDI), p-phenylene diisocyanate (PPDI) and o-toluene diisocyanate (TODI), ethylene diphenyl diisocyanate (EDI) or mixtures thereof, and the polyol composition comprising polytetrahydrofuran or a derivative thereof,

[0011] (ii) reacting the prepolymer obtained in step (i) with at least one chain extender (KV).

[0012] The present invention also relates to a thermoplastic polyurethane obtainable or obtained by the process according to the invention.

[0013] Surprisingly, it has been found that the use of the components used in the present invention, in particular the use of the specific combination of the isocyanate (IZ) used and the specific polyol component, can obtain thermoplastic polyurethanes and foam pellets prepared therefrom, which have a high elastic modulus and a low softening point at the same time, so that the foam pellets have good processing properties to obtain molded products, while showing a low Tg of the soft phase. In addition, the foam pellets of the present invention have good mechanical properties, such as high elasticity and good resilience. The dynamic continuous use performance is also very good. Unexpectedly, according to the present invention, very good phase separation can be achieved, while the hard phase has a better melting ability, thereby obtaining harder and effectively processable foam pellets. More specifically, compared with conventional materials, the compression hardness can therefore be significantly increased. In addition, the thermoplastic polyurethane of the present invention and the foam pellets prepared therefrom have very good low temperature properties and good thermal stability.

[0014] In the context of the present invention, unless otherwise stated, the resilience is determined analogously to DIN 53512, April 2000; the difference to the standard is the test sample height, which should be 12 mm, but the test is performed with 20 mm to avoid sample "penetration" and substrate measurement, unless otherwise stated.

[0015] Surprisingly, it has been found that the thermoplastic polyurethanes according to the invention have good processability to give foam pellets which in turn can be processed further efficiently to give moldings which have, in particular, a high modulus of elasticity and very good resilience.

[0016] The method of the present invention comprises steps (i) and (ii). In step (i), an isocyanate composition (ZI) and a polyol composition (ZP) are converted to obtain a prepolymer having isocyanate groups, wherein the isocyanate composition comprises an isocyanate (l1) selected from the group consisting of naphthylene 1,5-diisocyanate (NDI), diphenylmethane 4,4'-diisocyanate (MDI), p-phenylene diisocyanate (PPDI) and o-toluene diisocyanate (TODI), ethylene diphenyl diisocyanate (EDI) or a mixture thereof, and the polyol comprises polytetrahydrofuran or a derivative thereof. In step (ii), the prepolymer obtained in step (i) is reacted with at least one chain extender (KV). According to the present invention, step (ii) can be carried out after step (i). However, both steps can also be carried out in one stage of the method.

[0017] In step (i), the isocyanate composition (ZI) is reacted with a polyol composition (ZP) comprising polytetrahydrofuran or a derivative thereof. According to the invention, the polyol composition (ZP) comprises at least one polytetrahydrofuran or a derivative thereof and may comprise other components, in particular other substances reactive toward isocyanates, such as other polyols. According to the invention, the polyol composition may also comprise a mixture of different polytetrahydrofurans having different average molecular weights or a mixture of polytetrahydrofuran and one or more derivatives thereof.

[0018] In a particularly preferred embodiment, the number average molecular weight Mn of the polytetrahydrofuran is 500 to 5000 g / mol, further preferably 550 to 2500 g / mol, particularly preferably 650 to 2000 g / mol. In another embodiment, the number average molecular weight Mn of the polytetrahydrofuran is 500 to 1400 g / mol.

[0019] According to the present invention, mixtures of various polytetrahydrofurans, i.e. mixtures of polytetrahydrofurans with different molecular weights, can also be used. According to the present invention, the polyol composition can also comprise other polyols. Suitable polyols themselves are known to those skilled in the art. Suitable examples are polyethers, polyesters or polycarbonates.

[0020] In the context of the present invention, polytetrahydrofuran is also referred to as α-hydro-ω-hydroxypoly(oxytetramethylene) glycol.

[0021] According to the present invention, the polyol composition comprises polytetrahydrofuran or its derivatives. In the context of the present invention, derivatives are also understood to mean, for example, reaction products of polytetrahydrofuran. Suitable derivatives are also those obtained, for example, by reacting the free hydroxyl groups of polytetrahydrofuran. Suitable derivatives are, for example, poly-ε-caprolactone polyols, i.e., polyols obtained by reacting ε-caprolactone with polytetrahydrofuran as a starting molecule.

[0022] In another embodiment, the present invention also relates to a process as described above, wherein the poly-ε-caprolactone polyol used is obtainable or obtained by reacting ε-caprolactone with a starter molecule selected from α-hydro-ω-hydroxypoly(oxytetramethylene) glycol.

[0023] According to the present invention, the polyol composition may also comprise other poly-ε-caprolactone polyols, in particular those having a number average molecular weight of 500 to 5000 g / mol, preferably 1000 to 5000 g / mol, further preferably 1500 to 2500 g / mol. Poly-ε-caprolactone diols are preferably used, i.e. those poly-ε-caprolactone polyols obtained or obtainable using bifunctional initiators. In the context of the present invention, suitable initiators are, for example, diols having a number average molecular weight of 80 to 1500 g / mol, such as polyether polyols or polyester polyols. Polyether polyols are particularly suitable.

[0024] In a further embodiment, the present invention therefore also relates to a process as described above, wherein the poly-ε-caprolactone polyol used is obtainable or obtained by reaction of ε-caprolactone with a starter molecule selected from diols having a number average molecular weight of 50 to 1500 g / mol, preferably 80 to 2500 g / mol, further preferably 80 to 1500 g / mol.

[0025] Suitable starter molecules are selected in particular from neopentyl glycol (NPG), butane-1,4-diol (BDO), hexane-1,6-diol (HDO) and long-chain polyether diols having a number average molecular weight of 500 to 1500 g / mol, preferably 800 to 1200 g / mol, further preferably 900 to 1100 g / mol.

[0026] In the context of the present invention, unless stated otherwise, the number-average molecular weight is obtained by determining the OH number. Suitable measurement conditions are known to the person skilled in the art.

[0027] In another embodiment, the present invention also relates to a process as described above, wherein the poly-ε-caprolactone polyol used is obtainable or obtained by reacting ε-caprolactone with a starter molecule selected from α-hydrogen-ω-hydroxypoly(oxytetramethylene) glycol, polyethylene glycol and polypropylene glycol, preferably selected from α-hydrogen-ω-hydroxypoly(oxytetramethylene) glycol having a number average molecular weight of 150 to 1500 g / mol, polyethylene glycol having a number average molecular weight of 150 to 1500 g / mol and polypropylene glycol having a number average molecular weight of 150 to 1500 g / mol.

[0028] The polyol composition (ZP) may contain other α-hydrogen-ω-hydroxy poly (oxytetramethylene) polyols as other isocyanate-reactive compounds. Suitable α-hydrogen-ω-hydroxy poly (oxytetramethylene) polyols are known per se. In the context of the present invention, suitable are hydrogen-ω-hydroxy poly (oxytetramethylene) polyols preferably having a number average molecular weight of 1000 to 5000 g / mol, preferably 1500 to 2500 g / mol. In the context of the present invention, mixtures of two or more hydrogen-ω-hydroxy poly (oxytetramethylene) polyols with different molecular weights may also be used.

[0029] In another embodiment, the present invention therefore also relates to a process as described above, wherein the derivative of polytetrahydrofuran is a poly-ε-caprolactone polyol.

[0030] The composition of the polyol composition (ZP) can vary within a wide range. Preferably, in the context of the present invention, the proportion of α-hydrogen-ω-hydroxy poly(oxytetramethylene) polyol in the polyol composition (ZP) is from 0.1 wt.-% to 50 wt.-%, preferably from 10 wt.-% to 35 wt.-%, more preferably from 15 wt.-% to 25 wt.-%. In a preferred embodiment, the polyol composition (ZP) consists of poly-ε-caprolactone polyol and α-hydrogen-ω-hydroxy poly(oxytetramethylene) polyol.

[0031] In another embodiment, the present invention also relates to a method as described above, wherein the polyol composition comprises α-hydro-ω-hydroxypoly(oxytetramethylene)polyol in an amount of 0.1 wt % to 50 wt %, based on the polyol composition.

[0032] In another embodiment, the present invention also relates to the method as described above, wherein the number average molecular weight of the poly-ε-caprolactone polyol and / or the α-hydro-ω-hydroxypoly(oxytetramethylene) polyol is 1500 to 2500 g / mol.

[0033] For example, the number average molecular weight of both polyols in a mixture of poly-ε-caprolactone polyol and α-hydro-ω-hydroxy poly(oxytetramethylene) polyol is about 2000 g / mol.

[0034] Unless stated otherwise, the number average molecular weight Mn in the context of the present invention is determined by GPC.

[0035] The process of the invention can also be carried out in such a way that in the reaction of step (i), the polyol component (ZP) comprises other polyols and polytetrahydrofuran and its derivatives. Suitable polyols are known in principle to those skilled in the art and are described, for example, in "Kunststoffhandbuch [Plastics Handbook], Volume 7, Polyurethane [Polyurethanes]", Carl Hanser Verlag, 3rd edition, 1993, Chapter 3.1. Polyols (P1) are particularly preferably used as polyester alcohols or polyether alcohols as polyols. Polycarbonates can also be used. In the context of the present invention, copolymers can also be used.

[0036] According to the invention, polyetherols and also polyesterols, block copolymers and hybrid polyols such as poly(ester / amide)s are suitable. According to the invention, preferred polyetherols are polyethylene glycols, polypropylene glycols, polyadipates, polycarbonates, polycarbonate diols and polycaprolactones.

[0037] The polyols / polyol combinations used preferably have an average functionality of from 1.8 to 2.3, preferably from 1.9 to 2.2, in particular 2. The polyols used according to the invention preferably have only primary hydroxyl groups.

[0038] According to the invention, no water may advantageously be used in the reaction in step (i) or in the reaction in step (ii) or in both the reaction in step (i) and the reaction in step (ii). In one embodiment of the invention, a polyol component comprising less than 100 ppm of water may therefore be used.

[0039] According to the present invention, the reaction in step (i) may be carried out at a temperature of, for example, 110 to 180° C., preferably 130 to 170° C., more preferably 140 to 155° C. to obtain a prepolymer having an isocyanate group.

[0040] According to the invention, the isocyanate-terminated prepolymers thus obtained preferably have an NCO content of 2% to 20% by weight, more preferably 2% to 10% by weight and in particular 2% to 5% by weight. Depending on the NCO content, the prepolymers obtained generally have a viscosity of 800 to 5000 mPas at 80° C., measured with a rotational viscometer.

[0041] The isocyanate-terminated prepolymer is preferably prepared by using at least 50 wt. %, more preferably at least 80 wt. %, even more preferably at least 90 wt. %, in particular 100 wt. % of the polyol component. In the context of the present invention, other polyols may also be used in the reaction in step (ii).

[0042] In the context of the present invention, the composition of the polyol composition (PZ) can vary within wide ranges. According to the invention, the polyol composition may also comprise a solvent. Suitable solvents are known per se to the person skilled in the art.

[0043] In another embodiment, the present invention therefore also relates to a process as described above, wherein the further components used in the reaction in step (ii) are selected from polyols, chain extenders, catalysts, cell nucleating agents, other auxiliaries and additives.

[0044] In step (i), an isocyanate composition (ZI) is also used. According to the present invention, the isocyanate composition (ZI) comprises an isocyanate (l1) selected from the group consisting of naphthylene 1,5-diisocyanate (NDI), diphenylmethane 4,4'-diisocyanate (MDI), p-phenylene diisocyanate (PPDI) and o-toluene diisocyanate (TODI), ethylene diphenyl diisocyanate (EDI) or mixtures thereof. According to the present invention, the isocyanate composition (ZI) may also comprise other isocyanates. Preferably, the isocyanate composition (ZI) comprises an isocyanate (l1) selected from the group consisting of naphthylene 1,5-diisocyanate (NDI), p-phenylene diisocyanate (PPDI) and o-toluene diisocyanate (TODI), ethylene diphenyl diisocyanate (EDI) or mixtures thereof. Further preferably, the isocyanate composition (ZI) comprises naphthylene 1,5-diisocyanate (NDI) as the isocyanate (I1).

[0045] It has been found that, in particular when using naphthylene 1,5-diisocyanate (NDI) or isocyanate mixtures comprising naphthylene 1,5-diisocyanate (NDI) and other isocyanates, thermoplastic polyurethanes with advantageous properties are obtained. According to the invention, for example, mixtures comprising naphthylene 1,5-diisocyanate (NDI) and diphenylmethane 4,4'-diisocyanate (MDI) can also be used. Suitable mixtures can comprise, for example, naphthylene diisocyanate (NDI) and diphenylmethane 4,4'-diisocyanate (MDI) in a ratio of 50:50 to 30:70.

[0046] In the context of the present invention, suitable further isocyanates are especially diisocyanates, especially aliphatic or aromatic diisocyanates, more preferably aromatic diisocyanates.

[0047] Furthermore, in the context of the present invention, a pre-reaction product of the reaction of some OH components with isocyanates in a previous reaction step can be used as isocyanate component. In a subsequent step, the resulting product is reacted with the remaining OH components - the actual polymer reaction, thereby forming a thermoplastic polyurethane.

[0048] If further isocyanates are used, they are preferably present in the isocyanate composition (ZI) in an amount of 0.1 to 20% by weight, further preferably 0.1 to 10% by weight, particularly preferably 0.5 to 5% by weight.

[0049] The polyisocyanate composition may also contain one or more solvents. Suitable solvents are known to those skilled in the art. Suitable examples are non-reactive solvents such as ethyl acetate, methyl ethyl ketone and hydrocarbons.

[0050] In another embodiment, the present invention therefore also relates to a process as described above, wherein the polyisocyanate composition comprises an isocyanate selected from the group consisting of naphthylene 1,5-diisocyanate (NDI), diphenylmethane 4,4′-diisocyanate (MDI), p-phenylene diisocyanate (PPDI) and o-toluene diisocyanate (TODI), ethylene diphenyl diisocyanate (EDI) or mixtures thereof, the amount of the isocyanate being from 90% to 100% by weight, based on the total polyisocyanate composition.

[0051] In a further embodiment, the present invention therefore also relates to a process as described above, wherein the polyisocyanate composition comprises naphthylene 1,5-diisocyanate (NDI) in an amount of 90% to 100% by weight, based on the total polyisocyanate composition.

[0052] In step (ii), the prepolymer obtained in step (i) is reacted with at least one chain extender (KV). The prepolymer obtained is preferably reacted with a chain extender (KV) in step (ii), with the optional addition of further polyols or other chain extenders and optionally catalysts, optionally blowing agents and / or crosslinking agents and optionally auxiliaries and / or additives, if they have not already been added or were only partially added in the first step. In one embodiment of the invention, the chain extender used contains less than 100 ppm of water.

[0053] According to the invention, the prepolymer obtained in step (i) is preferably reacted in step (ii) in such an amount that in this step, the equivalent ratio of NCO groups to the sum of reactive hydrogen atoms is from 0.8:1 to 1.5:1, preferably from 0.85:1 to 1.3:1, in particular from 1.02:1 to 1.15:1. A ratio of 1:1 corresponds to an isocyanate index of 100. In the context of the present invention, the isocyanate index is understood to mean the stoichiometric ratio of isocyanate groups to isocyanate-reactive groups multiplied by 100.

[0054] Suitable chain extenders are known per se to the person skilled in the art. Chain extenders are, for example, compounds having two groups reactive toward isocyanate groups, in particular those having a molecular weight of less than 500 g / mol. Suitable chain extenders are, for example, diamines or diols. According to the invention, diols are further preferred. In the context of the present invention, mixtures of two or more chain extenders can also be used.

[0055] In a further embodiment, the present invention therefore also relates to a process as described above, wherein the chain extender (KV) is selected from diols having a molecular weight of 50 to 500 g / mol and diamines having a molecular weight of 50 to 500 g / mol.

[0056] According to the invention, aliphatic, araliphatic, aromatic and / or cycloaliphatic diols having a molecular weight of 50 g / mol to 220 g / mol can be used as chain extenders. Preference is given to alkanediols having 2 to 10 carbon atoms in the alkylene group, in particular di-, tri-, tetra-, penta-, hexa-, hepta-, octa-, nona- and / or decaalkylene diols. MEG, butane-1,4-diol, propane-1,3-diol and hexane-1,6-diol are particularly preferred for the present invention.

[0057] In the context of the present invention, suitable chain extenders (KV) are also branched compounds, for example cyclohexyl-1,4-dimethanol, 2-butyl-2-ethylpropanediol, neopentyl glycol, 2,2,4-trimethylpentane-1,3-diol, pinacol, 2-ethylhexane-1,3-diol or cyclohexane-1,4-diol.

[0058] In another embodiment, the present invention therefore also relates to a process as described above, wherein the chain extender (KV) is selected from MEG, butane-1,4-diol, propane-1,3-diol, hexane-1,6-diol, 2-ethylhexane-1,3-diol or 2-butyl-2-ethylpropanediol. According to the invention, it is also possible to use a mixture of two or more chain extenders selected from MEG, butane-1,4-diol, propane-1,3-diol, hexane-1,6-diol, 2-ethylhexane-1,3-diol or 2-butyl-2-ethylpropanediol.

[0059] The quantitative ratios of the components used in step (ii) are preferably selected so as to obtain a hard segment content of 10% to 40%.

[0060] According to the invention, the reaction in step (i) and step (ii) can be carried out in two separate steps. According to the invention, alternatively, the process can be carried out in one stage. According to the invention, the process can be carried out in a multistage or continuous operation, for example in a reaction extruder, wherein the prepolymer is prepared continuously in the first zone. It is also possible, for example, to first prepare the prepolymer continuously according to step (i) in a tubular reactor or tank and then carry out step (ii), for example in the form of a reaction in a belt extruder or reaction extruder process.

[0061] Particularly in the case of use of isocyanate compositions comprising NDI and TODI, it has been found to be advantageous to carry out the process in a two-stage operation. According to the invention, in this context, advantageously, firstly the polyol component, the isocyanate component and optionally auxiliaries or additives and optionally catalysts are reacted in a first reaction, and then the resulting prepolymer is reacted with the chain extender and optionally auxiliaries or additives, cell nucleating agents and catalysts. According to the invention, the NCO / OH ratio is preferably from 0.85 to 1.30.

[0062] It has been found that, for example, in the case of the use of MDI, a one-stage process variant is advantageous.

[0063] In another aspect, the present invention also relates to a thermoplastic polyurethane obtainable or obtained by a process comprising at least steps (i) and (ii):

[0064] (i) converting at least one isocyanate composition (ZI) and a polyol composition (ZP) to obtain a prepolymer having isocyanate groups, the isocyanate composition comprising an isocyanate (l1) selected from the group consisting of naphthylene 1,5-diisocyanate (NDI), diphenylmethane 4,4'-diisocyanate (MDI), p-phenylene diisocyanate (PPDI) and o-toluene diisocyanate (TODI), ethylene diphenyl diisocyanate (EDI) or mixtures thereof, and the polyol composition comprising polytetrahydrofuran or a derivative thereof,

[0065] (ii) reacting the prepolymer obtained in step (i) with at least one chain extender (KV).

[0066] With regard to preferred embodiments, reference is made to the above description of preferred starting materials and reaction conditions.

[0067] Surprisingly, it has been found that the thermoplastic polyurethanes according to the invention are particularly suitable for preparing foam pellets. The foam pellets obtained have good mechanical properties, in particular very good resilience.

[0068] Therefore, in a further aspect, the present invention also relates to a foam pellet comprising a thermoplastic polyurethane obtainable or obtained by the process of the present invention or a thermoplastic polyurethane of the present invention.

[0069] The foam pellets of the present invention have good processing properties to obtain mouldings. More specifically, it has been found that the foam pellets have good weldability. In another aspect, the present invention also relates to mouldings made from the foam pellets as described above.

[0070] The invention furthermore relates to the use of the thermoplastic polyurethanes obtainable or obtained by the process according to the invention or of the thermoplastic polyurethanes according to the invention for preparing moldings or foam pellets.

[0071] In addition to the properties of the thermoplastic polyurethane, the method for preparing the foam pellets generally also has a significant influence on the performance characteristics of the resulting beads.

[0072] In another aspect, the present invention also relates to a method for preparing foam pellets. In this case, the present invention relates to a method for preparing foam pellets, which comprises the following steps:

[0073] (i) providing a composition (Z1) comprising a thermoplastic polyurethane, wherein the thermoplastic polyurethane is obtainable or obtained by a process comprising at least steps (a) and (b):

[0074] (a) converting at least one isocyanate composition (ZI) and a polyol composition (ZP) to obtain a prepolymer having isocyanate groups, the isocyanate composition comprising an isocyanate (I1) selected from the group consisting of naphthylene 1,5-diisocyanate (NDI), diphenylmethane 4,4'-diisocyanate (MDI), p-phenylene diisocyanate (PPDI) and o-toluene diisocyanate (TODI), ethylene diphenyl diisocyanate (EDI) or mixtures thereof, and the polyol composition comprising polytetrahydrofuran or a derivative thereof,

[0075] (b) reacting the prepolymer obtained in step (a) with at least one chain extender (KV);

[0076] (ii) impregnating the composition (Z1) with a blowing agent under pressure;

[0077] (iii) expanding the composition (Z1) by reducing the pressure.

[0078] In the context of the present invention, the composition (Z1) here can be used in the form of a melt or in the form of pellets.

[0079] With regard to preferred embodiments of the process, suitable starting materials or mixing ratios, reference is made to the correspondingly applicable above statements.

[0080] The method of the invention may comprise further steps, such as temperature regulation.

[0081] The unexpanded polymer mixture of the composition (Z1) required for preparing the foam pellets is prepared in a known manner from the individual components and optionally further components such as processing aids, stabilizers, compatibilizers or pigments. Examples of suitable processes are conventional mixing processes by means of kneaders in a continuous or batchwise manner or by means of extruders (e.g. co-rotating twin-screw extruders).

[0082] In the case of compatibilizers or auxiliaries (e.g. stabilizers), these can also be incorporated into the components during the preparation of the components. The components are usually mixed before the mixing process or metered into the device where the mixing takes place. In the case of an extruder, the components are metered all into the feed opening and conveyed together into the extruder, or the components are added by side feeding.

[0083] The treatment is carried out at a temperature at which the components exist in a plasticized state. The temperature depends on the softening or melting range of the components, but must be below the decomposition temperature of each component. Additives such as pigments or fillers or other commonly used additives mentioned above (e.g. flame retardants or antistatic additives) are also not melted, but are incorporated in the solid state.

[0084] In this context, other embodiments using established processes are possible, and the processes used in the preparation of the raw materials can be directly integrated into the preparation. For example, in the case of a belt process, in which the material is fed to an extruder to obtain lens-shaped pellets, the polymer, impact modifier, and filler or dye can be introduced directly at the end of the belt.

[0085] In this step, some of the above-mentioned common adjuvants may be added to the mixture.

[0086] The bulk density of the foam pellets of the present invention is generally from 50 g / l to 200 g / l, preferably from 60 g / l to 180 g / l, more preferably from 80 g / l to 150 g / l.

[0087] As mentioned above, the diameter of the individual beads of foam pellets is from 0.5 to 30 mm, preferably from 1 to 15 mm, in particular from 3 to 12 mm. In the case of non-spherical foam pellets, for example elongated or cylindrical foam pellets, the diameter means the longest dimension.

[0088] The foam pellets can be prepared by the following methods known in the art:

[0089] (i) providing the composition (Z1) of the present invention;

[0090] (ii) impregnating the composition with a blowing agent under pressure;

[0091] (iii) expanding the composition by reducing the pressure.

[0092] The amount of the blowing agent is preferably 0.1 to 50 parts by weight, especially 0.5 to 35 parts by weight, and more preferably 1 to 30 parts by weight, based on 100 parts by weight of the composition (Z1).

[0093] One embodiment of the above method comprises

[0094] (i) providing a composition (Z1) according to the present invention in the form of pellets;

[0095] (ii) impregnating the pellets with a blowing agent under pressure;

[0096] (iii) Expansion of the pellets by reducing the pressure.

[0097] Another embodiment of the above method comprises the additional steps of:

[0098] (i) providing a composition (Z1) according to the present invention in the form of pellets;

[0099] (ii) impregnating the pellets with a blowing agent under pressure;

[0100] (iii-a) reducing the pressure to standard pressure without foaming the pellets, optionally by previously reducing the temperature,

[0101] (iii-b) The pellets are expanded by increasing the temperature.

[0102] In this context, the unexpanded granules preferably have an average minimum diameter of from 0.2 to 10 mm (determined by 3D evaluation of the granules, for example by dynamic image analysis using a PartAn 3D optical measuring device from Microtrac).

[0103] In another embodiment, the present invention also relates to a method for preparing the above-mentioned foam pellets, wherein polyurethane is impregnated with a blowing agent in an extruder, the impregnated polyurethane is cut into pellets, and the pellets are expanded immediately after cutting to obtain expanded thermoplastic polyurethane beads.

[0104] The average mass of a single pellet is generally 0.1 to 100 mg, for example 1 to 50 mg, preferably 4 to 40 mg, and more preferably 7 to 32 mg. The average mass (bead weight) of such pellets is determined as the arithmetic mean obtained by weighing three batches of 10 pellet particles per batch.

[0105] One embodiment of the above method comprises impregnating the pellets with a blowing agent under pressure in steps (I) and (II) and subsequently expanding the pellets:

[0106] (I) impregnating pellets in the presence of a blowing agent at elevated temperature and pressure in a suitable closed reaction vessel (e.g., an autoclave);

[0107] (II) Sudden expansion without cooling.

[0108] In this context, the impregnation in step (I) can be carried out in the presence of water and optionally a suspension agent or suspension aid, or only in the presence of a foaming agent and in the absence of water.

[0109] Suitable suspension aids are, for example, water-insoluble inorganic solids, such as tricalcium phosphate, magnesium pyrophosphate, metal carbonates, as well as polyvinyl alcohol and ionic surfactants, such as sodium dodecyl aryl sulfonate, or nonionic surfactants. They are usually used alone or in combination in an amount of 0.05% to 10% by weight, based on the composition of the invention.

[0110] Depending on the selected pressure, the impregnation temperature is 90°C to 200°C, preferably 100°C-200°C, and further preferably 100°C to 180°C, wherein the pressure in the reaction vessel is 2-250 bar, preferably 5 to 100 bar, and more preferably 20 to 60 bar, and the impregnation time is generally 0.5 to 10 hours.

[0111] In another embodiment, the present invention also relates to a method for preparing foam pellets as described above, wherein in step (i) the pellets are impregnated with 0.1 wt % to 50 wt % of a blowing agent at a temperature of 90 to 180° C. and a pressure of 0.5 to 10 MPa.

[0112] The performance of the method in suspension is known to the person skilled in the art and is described in detail, for example, in WO 2007 / 082838.

[0113] If the process is carried out without a blowing agent, care must be taken to avoid agglomeration of the polymer pellets.

[0114] Suitable blowing agents for carrying out the process in a suitable closed reaction vessel are, for example, organic liquids and gases which are gaseous under the process conditions, such as hydrocarbons or inorganic gases or mixtures of organic liquids or gases with inorganic gases, where these can also be combined.

[0115] Examples of suitable hydrocarbons are halogenated or non-halogenated, saturated or unsaturated aliphatic hydrocarbons, preferably non-halogenated, saturated or unsaturated aliphatic hydrocarbons.

[0116] Preferred organic blowing agents are saturated aliphatic hydrocarbons, especially those having 3 to 8 carbon atoms, such as butane or pentane.

[0117] Suitable inorganic gases are nitrogen, air, ammonia or carbon dioxide, preferably nitrogen or carbon dioxide, or mixtures of the above gases.

[0118] In another embodiment, impregnation of the pellets with a blowing agent under pressure comprises treatment and subsequent expansion of the pellets in steps (α) and (β):

[0119] (a) impregnating pellets in an extruder under pressure and high temperature in the presence of a blowing agent;

[0120] (β) The composition from the extruder is pelletized under conditions ensuring controlled foaming.

[0121] In a variant of the method, suitable blowing agents are volatile organic compounds whose boiling points at a standard pressure of 1013 mbar are in the range of -25°C to 150°C, in particular -10°C to 125°C. Very suitable are hydrocarbons (preferably halogen-free), in particular C4-10 alkanes, such as butane, pentane, hexane, heptane and isomers of octane, more preferably isobutane. Other possible blowing agents are also sterically more demanding compounds, such as alcohols, ketones, esters, ethers and organic carbonates.

[0122] Herein, in step (α), the composition is mixed in an extruder under pressure in a molten state with a blowing agent supplied to the extruder. The mixture containing the blowing agent is extruded and granulated under pressure, preferably with the back pressure (Gegendruck) controlled to a moderate level (e.g. underwater granulation). In the method, the molten strands are foamed and granulated to obtain foamed pellets.

[0123] The implementation of the process by extrusion is known to the person skilled in the art and is described in detail, for example, in WO 2007 / 082838 and WO 2013 / 153190 A1.

[0124] In one embodiment, for example, the polyurethane can be impregnated with a blowing agent in an extruder, the impregnated polyurethane can be cut into pellets, and the pellets can be expanded after cutting to obtain expanded thermoplastic polyurethane beads. In order to impregnate the polyurethane with a blowing agent, the thermoplastic polyurethane is mixed with the blowing agent supplied to the extruder in a molten state in an extruder. The mixture containing the blowing agent is then extruded and pelletized under pressure and temperature conditions that can obtain expanded foam beads. The pressure and temperature here depend on the amount of polyurethane and blowing agent used. The pressure is generally 1 to 20 bar, preferably 2 to 15 bar, and the temperature is 20°C to 60°C, preferably 20°C to 40°C.

[0125] The preparation of the thermoplastic polyurethane and the addition of the blowing agent for the preparation of the expanded thermoplastic polyurethane can be carried out in two different extruders. Alternatively, however, it is also possible to use only one extruder. In this case, the front part of the extruder is used as a reactive extruder, the isocyanate, isocyanate-reactive compound, chain extender and any other additives are added to the front part of the extruder, and the blowing agent is added at a downstream point of the extruder, at which point the conversion to the polyurethane is completed.

[0126] In an alternative embodiment, the preparation of foam pellets from the thermoplastic polyurethane of the present invention comprises steps (a) to (c):

[0127] (a) providing a thermoplastic polyurethane in the form of beads in the form of pellets of suitable geometry,

[0128] (b) impregnating the pellets with a blowing agent under pressure and temperature in a tank or autoclave,

[0129] (c) The tank is spontaneously depressurized, producing foam beads as the pressure drops and the blowing agent dissolved in the pellets expands.

[0130] Typically, the thermoplastic PU is converted into pellets of the desired shape directly or in a separate step (a) during its preparation. Preference is given to using cylindrical, oval or spherical pellets with an average diameter of 0.2 to 10 mm, especially 0.5 to 5 mm. In the case of cylindrical or oval pellets, the diameter refers to the longest dimension.

[0131] The average mass of a single granule is generally 1 to 100 mg, preferably 2 to 60 mg, further preferably 3 to 50 mg and more preferably 4-35 mg. The average mass (bead weight) of such granules is determined as the arithmetic mean obtained by weighing three batches of 10 granule particles per batch. Such preferably cylindrical or round granules can be prepared by any mixing method known to those skilled in the art and subsequently granulated in cold or hot chopped form.

[0132] Typically, such granules are impregnated in step (b) with 0.1% to 50% by weight of a blowing agent in an aqueous suspension at a temperature of 90 to 180° C. and a pressure of 0.5 to 10 MPa. Subsequently, the aqueous hydrothermal suspension containing the granules is suddenly expanded without cooling (explosive expansion process), causing the softened beads containing the blowing agent to foam directly to give expanded beads. Expanded thermoplastic polyurethanes can in principle be prepared as described in WO-A 2007 / 082838.

[0133] The blowing agent used to prepare the expanded thermoplastic polyurethane beads may vary depending on the preparation method.

[0134] In the case of adding a blowing agent to the extruder or the impregnation tank, the blowing agent used is preferably a volatile organic compound whose boiling point at a standard pressure of 1013 mbar is from -25 to 160° C., in particular from -10 to 125° C. Very suitable are optionally halogenated hydrocarbons, preferably halogen-free hydrocarbons. Particularly preferred are C4-C 10 Alkanes, for example butane, pentane, cyclopentane, hexane, heptane and isomers of octane, more preferably sec-pentane. Suitable blowing agents are also sterically more demanding compounds, for example alcohols, ketones, esters, ethers and organic carbonates. According to the invention, mixtures of the mentioned blowing agents can also be used. Suitable inorganic gases are, for example, nitrogen, air, ammonia or carbon dioxide, or combinations of these or with the above-mentioned other blowing agents.

[0135] The inorganic gases mentioned can also be used in the case of impregnation in an autoclave. Halogenated hydrocarbons can also be used, but the blowing agent is preferably halogen-free. However, small amounts of halogenated blowing agents in the blowing agent mixture are not excluded. The blowing agent can be used as a pure substance or in the form of any mixture.

[0136] In the case of the preparation of expanded thermoplastic pellets by extrusion and in aqueous suspension, it is also possible, in addition to the blowing agents mentioned, to use nitrogen and / or carbon dioxide, in particular supercritical carbon dioxide.

[0137] The amount of blowing agent is preferably 0.1 to 50 parts by weight, in particular 0.5 to 40 and more preferably 1 to 30 parts by weight, based on 100 parts by weight of the thermoplastic polyurethane used.

[0138] Nitrogen can also be used as a co-blowing agent by injecting and raising the internal pressure in the impregnation reactor by 200 to 3000 kPa at a temperature below the onset of the first melting peak in the DSC of the thermoplastic elastomer (eg, 30 to 75°C).

[0139] The impregnation in step (b) is preferably carried out at an impregnation temperature IMT of 90 to 190° C. For this purpose, the suspension is usually heated to the impregnation temperature (IMT) at a heating rate of preferably 2° C. / min or more and optionally kept at this temperature or in a range of 2° C. above the IMT to 5° C. below the IMT for 2 to 100 minutes (holding time HZ).

[0140] The granules obtained in step (b) containing the blowing agent are foamed in the subsequent step (c) by expansion into foam beads. In step (c) the suspension is usually expanded by emptying the pressure vessel via an open stop valve into an expansion vessel.

[0141] The bulk density of the foam pellets composed of the thermoplastic polyurethane of the present invention obtainable by the process of the present invention is preferably 20 to 250 kg / m 3, more preferably 35 to 150 kg / m 3 .

[0142] The foam pellets are usually at least approximately spherical. The exact geometry or diameter depends on the geometry chosen and the particle weight of the original pelletized material and on the resulting bulk density.

[0143] Therefore, the present invention also relates to foam pellets obtained by the above process, wherein the average diameter of the pellets is preferably from 0.5 to 20 mm.

[0144] The maximum linear expansion of the particles is generally from 1 to 25 mm, preferably from 2 to 15 mm and most preferably has a maximum linear expansion of 3-10 mm.

[0145] The expanded foam beads produced according to the invention generally have predominantly closed cells, the volume fraction of closed cells being determined in accordance with DIN EN ISO 4590 as of August 1, 2003, and generally have a cell density (cell number / area) of 1 to 750 cells / mm 2 , preferably 2 to 500 cells / mm 2 , especially 5 to 200 cells / mm 2 And more preferably 10 to 100 cells / mm 2 .

[0146] Suitable apparatuses for carrying out the process according to the invention for producing foam beads are known per se to the person skilled in the art.

[0147] Extruders which can be used are any customary screw-based machines, in particular single-screw and twin-screw extruders (e.g. ZSK type from Werner & Pfleiderer), co-kneaders, Kombiplast machines, MPC kneading mixers, FCM mixers, KEX kneading screw extruders and shear roll extruders, as described, for example, in Saechtling (ed.), Kunststoff-Taschenbuch, 27th edition, Hanser-Verlag, Munich 1998, chapters 3.2.1 and 3.2.4. The extruder is generally operated at a temperature at which the composition (Z1) is present in the form of a melt, for example 120° C. to 250° C., in particular 150° C. to 210° C., and, to ensure homogenization of the blowing agent with the melt, after addition of the blowing agent, at a pressure of 40 to 200 bar, preferably 60 to 150 bar, more preferably 80 to 120 bar.

[0148] The method of the present invention can be carried out in one extruder or in an apparatus consisting of one or more extruders. Thus, for example, the components can be melted and blended in the first extruder and the blowing agent injected. In the second extruder, the impregnated melt is homogenized and the temperature and / or pressure is adjusted. For example, if three extruders are combined with each other, the mixing of the components and the injection of the blowing agent can also be divided between two different method parts. If it is preferred to use only one extruder, all method steps - melting, mixing, injection of blowing agent, homogenization and adjustment of temperature and / or pressure - are carried out in a single extruder.

[0149] As an alternative, corresponding foam granules, which may even be already colored, can be prepared directly from the granules according to the method described in WO 2014 / 150122 or WO 2014 / 150124 A1 in such a way that the corresponding granules are impregnated with a supercritical liquid and removed from the supercritical liquid and then

[0150] (i') immersing the article in a heated fluid, or

[0151] (ii') irradiating the article with high energy radiation (eg infrared or microwave radiation).

[0152] Examples of suitable supercritical liquids are those described in WO2014150122, or for example carbon dioxide, nitrogen dioxide, ethane, ethylene, oxygen or nitrogen, preferably carbon dioxide or nitrogen.

[0153] The supercritical liquid herein may also include a Hildebrand solubility parameter equal to or greater than 9 MPa -1 / 2 of polar liquid.

[0154] The supercritical fluid or heated fluid herein may also contain a dye, thereby obtaining a colored foam article.

[0155] Expanded thermoplastic polyurethane beads, ie foam pellets, are used in particular for preparing moldings from the bead foam. In another aspect, the invention also relates to moldings made from the foam pellets as described above. Methods for preparing such moldings are known per se.

[0156] In another aspect, the present invention also relates to the use of the foam pellets according to the invention or obtained or obtainable by the process according to the invention for the preparation of moldings. In another embodiment, the present invention therefore also relates to the use of the foam pellets according to the invention or obtained or obtainable by the process according to the invention for the preparation of moldings, wherein the moldings are produced by fusing or bonding the beads to one another.

[0157] In a further aspect, the present invention also relates to the use of the foam pellets according to the invention for producing moldings. The present invention also provides moldings produced from the foam pellets according to the invention.

[0158] According to the present invention, a method suitable for preparing a molding from foam pellets comprises, for example, the following steps:

[0159] (A) introducing the foam pellets of the present invention into a suitable mold,

[0160] (B) fusing the foam pellets of the present invention from step (i).

[0161] The fusion in step (B) is preferably carried out in a closed mold, wherein the fusion can be carried out by steam, hot air (eg described in EP1979401B1) or high-energy radiation (microwaves or radio waves).

[0162] The fusion temperature of the foam pellets is preferably below or close to the melting temperature of the polymer from which the bead foam is prepared. For standard polymers, the fusion temperature of the foam pellets is therefore between 100°C and 180°C, preferably between 120°C and 150°C.

[0163] In this context, the temperature profile / residence time can be determined individually, for example analogously to the methods described in US20150337102 or EP2872309B1.

[0164] Fusion by high-energy radiation is generally carried out in the frequency range of microwaves or radio waves, optionally in the presence of water or other polar liquids, such as microwave-absorbing hydrocarbons with polar groups (such as esters of carboxylic acids, and esters of diols or triols, or ethylene glycol and liquid polyethylene glycol), and can be carried out in a manner similar to that described in EP3053732A or WO16146537.

[0165] A preferred method for preparing individual moldings from such foam beads comprises the following steps:

[0166] (a) introducing expanded thermoplastic polyurethane beads into a mold;

[0167] (b) The expanded thermoplastic polyurethane beads introduced into the mold are contacted with steam, hot air or high-energy radiation so that the expanded thermoplastic polyurethane beads are melted and welded on the surface to form a molded product.

[0168] The heating of the surface of the beads of foam granules required for welding is achieved by contact with steam, hot air or high-energy radiation (each alone or in any combination) so that they melt at the surface. Suitable high-energy radiation is, for example, microwave radiation, radiofrequency radiation or infrared radiation. However, preference is given to using steam or hot air, especially steam.

[0169] In a further embodiment, the present invention therefore also relates to the use as described above, wherein the molding is produced by welding or bonding the beads to one another.

[0170] When steam is used to weld the polyurethane beads, the temperature of the steam introduced into the mold can be adjusted by the pressure. According to the present invention, in addition to saturated steam, superheated steam or unsaturated steam can also be used. The suitable pressure for introducing steam into the mold is, for example, 0.1 bar to 6 bar, preferably 0.3 to 3 bar.

[0171] As mentioned above, the foam pellets may also contain dyes. In this context, dyes may be added in a variety of ways.

[0172] In one embodiment, the prepared foam particles can be colored after preparation. In this case, the corresponding foam particles are contacted with a carrier liquid containing a dye, the carrier liquid (CL) having a polarity suitable for absorbing the carrier liquid into the foam particles. This can be carried out in a manner similar to that described in EP application No. 17198591.4.

[0173] Examples of suitable colorants are inorganic or organic pigments. Examples of suitable natural or synthetic inorganic pigments are carbon black, graphite, titanium oxide, iron oxide, zirconium oxide, cobalt oxide compounds, chromium oxide compounds, copper oxide compounds. Examples of suitable organic pigments are azo pigments and polycyclic pigments.

[0174] In another embodiment, color can be added during the preparation of foam pellets. For example, colorants can be added to the extruder during the preparation of foam pellets by extrusion.

[0175] As an alternative, already coloured material can be used as a starting material for preparing foam pellets by extruding or expanding them in a closed container by the above-described methods.

[0176] Furthermore, in the method described in WO2014150122, the supercritical liquid or the heated liquid may contain a dye.

[0177] As described above, the moldings according to the invention have advantageous properties for the above-mentioned applications required in the field of footwear and sports shoes.

[0178] The tensile and compressive properties of the moldings produced from the foam pellets are characterized by a tensile strength of more than 600 kPa (ASTM D 5035), an elongation at break of more than 100% (ASTM D503), a compressive stress at 10% compression of more than 15 kPa (similar to DIN EN ISO 844, November 2014; the difference from the standard is the height of the sample, 20 mm instead of 50 mm, so the test speed is adjusted to 2 mm / min).

[0179] The resilience of moldings made from foam pellets is preferably above 55% (similar to DIN 53512, April 2000; the difference from the standard is the test sample height, which should be 12 mm, but the test is carried out at 20 mm to avoid sample "penetration" and substrate measurement).

[0180] As mentioned above, there is a relationship between the density and compression properties of the molded article produced. The density of the molded article produced is advantageously 75 to 375 kg / m 3 , preferably 100 to 300 kg / m 3 , more preferably 150 to 200 kg / m 3 (DIN EN ISO 845, October 2009).

[0181] The ratio of the density of the molding to the bulk density of the foam pellets according to the invention (densification level VG) is generally from 1.5 to 3.5, preferably from 1.8 to 2.5.

[0182] The foam granules according to the invention can be processed particularly effectively to form shoe soles, shoe sole parts, mattresses, padding, grips, protective films, automotive interior and exterior components, gymnastics mats, body protectors, decorative elements in automobile construction, sound insulation, vibration dampers, cushioning elements, bicycle saddles, toys, tires or tire parts, or as coverings for athletic fields, gymnasiums or paths, vibration damping layers or vibration damping cores in sandwich elements, or packaging.

[0183] In a further embodiment, the present invention therefore also relates to the use as described above, wherein the molding is a sole, a sole component, a mattress, a liner, a grip, a protective film, a component for the interior and exterior of an automobile, a gymnastics mat, a body protector, a decorative element in automobile construction, a sound insulation material, a vibration damper, a cushioning element, a bicycle saddle, a toy, a tire or a tire component, or a covering for athletic surfaces, sports halls or paths, a vibration damping layer or a vibration damping core in a sandwich element, or a packaging.

[0184] In another aspect, the invention also relates to the use of foam pellets as described above in balls and sports equipment or as floor coverings and sidings, in particular for sports field surfaces, athletic field surfaces, gymnasiums, children's playgrounds and paths.

[0185] The moldings obtained according to the invention are suitable, for example, for the production of shoe soles, shoe sole parts, bicycle saddles, cushioning elements, mattresses, padding, grips, protective films, automotive interior and exterior components, for balls and sports equipment or as floor coverings and sidings, in particular for sports field surfaces, athletic field surfaces, sports halls, children's playgrounds and paths.

[0186] In a further embodiment, the present invention therefore also relates to the use of the foam granules according to the invention or of the foam granules obtained or obtainable by the process according to the invention for producing moldings, wherein the moldings are shoe soles, shoe sole parts, bicycle saddles, cushioning elements, mattresses, padding, grips, protective films, automotive interior and exterior components.

[0187] In a further aspect, the invention also relates to the use of the foam granules or beads according to the invention in balls and sports equipment or as floor coverings and sidings, in particular for sports field surfaces, athletic field surfaces, gymnasiums, children's playgrounds and paths.

[0188] On the other hand, the present invention also relates to a composite material comprising a matrix consisting of a polymer (PM) and a foam pellet of the present invention. In the context of the present invention, the material comprising foam pellets and a matrix material is referred to as a composite material. In this article, the matrix material can be made of a dense material or equally of foam.

[0189] The polymer (PM) that is suitable as matrix material itself is known to those skilled in the art. For example, in the context of the present invention, it is suitable to be ethylene-vinyl acetate copolymer, epoxy adhesive or polyurethane. According to the present invention, in this article, polyurethane foam or compact polyurethane, for example thermoplastic polyurethane is suitable.

[0190] According to the invention, in this context, the polymer (PM) is chosen such that there is sufficient adhesion between the foam particles and the matrix to obtain a mechanically stable composite material.

[0191] In this context, the matrix may completely or partially surround the foam pellets. According to the present invention, the composite material may include other components, such as other fillers or pellets. According to the present invention, the composite material may also include a mixture of different polymers (PM). The composite material may also include a mixture of foam pellets.

[0192] Besides the foam pellets according to the invention, foam pellets which are known per se to the person skilled in the art can also be used. In the context of the present invention, foam pellets made of thermoplastic polyurethane are particularly suitable.

[0193] In one embodiment, the present invention therefore also relates to a composite material comprising a matrix composed of a polymer (PM), foam pellets according to the invention and further foam pellets composed of a thermoplastic polyurethane.

[0194] In the context of the present invention, the matrix consists of a polymer (PM).In the context of the present invention, examples of suitable matrix materials are elastomers or foams, especially polyurethane-based foams, for example elastomers such as ethylene-vinyl acetate copolymers or thermoplastic polyurethanes.

[0195] The present invention therefore also relates to a composite material as described above, wherein the polymer (PM) is an elastomer. The present invention also relates to a composite material as described above, wherein the polymer (PM) is selected from ethylene-vinyl acetate copolymers and thermoplastic polyurethanes.

[0196] In one embodiment, the present invention also relates to a composite material comprising a matrix composed of ethylene-vinyl acetate copolymer and the foam pellets of the present invention.

[0197] In another embodiment, the present invention relates to a composite material comprising a matrix composed of ethylene vinyl acetate copolymer, foam pellets of the present invention, and other foam pellets composed of, for example, thermoplastic polyurethane.

[0198] In one embodiment, the present invention relates to a composite material comprising a matrix composed of a thermoplastic polyurethane and foam pellets of the present invention.

[0199] In another embodiment, the present invention relates to a composite material comprising a matrix composed of thermoplastic polyurethane, foam pellets of the present invention and further foam pellets, for example composed of thermoplastic polyurethane.

[0200] Suitable thermoplastic polyurethanes are known per se to the person skilled in the art. Suitable thermoplastic polyurethanes are described, for example, in "Kunststoffhandbuch, Volume 7, Polyurethane", Carl Hanser Verlag, 3rd edition 1993, Chapter 3.

[0201] In the context of the present invention, polymer (PM) is preferably polyurethane. "Polyurethane" within the meaning of the present invention includes all known elastic polyisocyanate polyaddition products. These include especially dense polyisocyanate polyaddition products, such as viscoelastic gels or thermoplastic polyurethanes, and elastic foams based on polyisocyanate polyaddition products, such as flexible foams, semi-rigid foams or integral foams. Within the meaning of the present invention, "polyurethane" is also understood to mean elastic polymer blends comprising polyurethane and other polymers, and foams of these polymer blends. The matrix is ​​preferably solidified, dense polyurethane adhesives, elastic polyurethane foams or viscoelastic gels.

[0202] In the context of the present invention, "polyurethane adhesive" is understood herein to mean a mixture consisting of at least 50% by weight, preferably at least 80% by weight, in particular at least 95% by weight of prepolymers having isocyanate groups (hereinafter referred to as isocyanate prepolymers). The viscosity of the polyurethane adhesives of the invention is preferably 500 to 4000 mPa.s, more preferably 1000 to 3000 mPa.s, measured at 25° C. in accordance with DIN 53 018.

[0203] In the context of the present invention, “polyurethane foam” is understood to mean a foam according to DIN 7726.

[0204] The density of the matrix material is preferably 1.2 to 0.01 g / cm 3 The matrix material is more preferably a material with a density of 0.8 to 0.1 g / cm 3 , especially 0.6 to 0.3 g / cm 3 Flexible or integral foam, or dense material such as cured polyurethane adhesive.

[0205] Foams are particularly suitable matrix materials. Composite materials comprising a matrix material consisting of polyurethane foam preferably have good adhesion between the matrix material and the foam pellets.

[0206] In one embodiment, the present invention also relates to a composite material comprising a matrix consisting of polyurethane foam and the foam pellets of the present invention.

[0207] In another embodiment, the present invention relates to a composite material comprising a matrix consisting of polyurethane foam, foam pellets of the present invention and further foam pellets consisting of, for example, thermoplastic polyurethane.

[0208] In one embodiment, the present invention relates to a composite material comprising a matrix composed of a polyurethane integral foam and the foam pellets of the present invention.

[0209] In another embodiment, the present invention relates to a composite material comprising a matrix consisting of a polyurethane integral foam, foam pellets of the present invention and further foam pellets consisting of, for example, thermoplastic polyurethane.

[0210] The composite material of the invention, which comprises a polymer (PM) as a matrix and foam pellets of the invention, can be prepared, for example, by mixing the components for preparing the polymer (PM) and the foam pellets and optionally further components, and reacting them to obtain the composite material, the reaction preferably being carried out under conditions under which the foam pellets are substantially stable.

[0211] Suitable processes and reaction conditions for the preparation of polymers (PM), in particular ethylene-vinyl acetate copolymers or polyurethanes, are known per se to the person skilled in the art.

[0212] In a preferred embodiment, the composite material of the invention is an integral foam, in particular an integral foam based on polyurethane. Suitable methods for preparing integral foams are known per se to the person skilled in the art. Integral foams are preferably prepared in a closed, advantageously temperature-controlled mold by a one-shot process using low-pressure or high-pressure technology. The mold is usually made of metal, for example aluminum or steel. These methods are described, for example, by Piechota and Described in "Integralschaumstoff" [Integral Foam], Carl-Hanser-Verlag, Munich, Vienna, 1975 or in "Kunststoff-Handbuch", volume 7, "Polyurethane", 3rd edition, 1993, chapter 7.

[0213] If the composite material according to the invention comprises an integral foam, the amount of the reaction mixture introduced into the mold is such that the resulting molding consisting of the integral foam has a density of from 0.08 to 0.70 g / cm 3 , especially 0.12 to 0.60 g / cm 3 The densification level for producing moldings having a dense edge region and a porous core is from 1.1 to 8.5, preferably from 2.1 to 7.0.

[0214] Therefore, composite materials having a matrix consisting of a polymer (PM) and incorporating the foam pellets of the present invention can be prepared, wherein the foam beads are evenly distributed. The foam pellets of the present invention can be easily used in methods for preparing composite materials, because the individual beads flow freely due to their small size, and there are no specific requirements for processing. In this context, techniques can be used to evenly distribute the foam pellets, such as slowly rotating the mold.

[0215] Optionally, further auxiliaries and / or additives may also be added to the reaction mixture to prepare the composite material of the invention. For example, surface-active substances, foam stabilizers, cell regulators, release agents, fillers, dyes, pigments, hydrolysis stabilizers, odor-absorbing substances and fungistatic and bacteriostatic substances may be mentioned.

[0216] Examples of surface-active substances that can be used are compounds that are used to support the homogenization of the raw materials and are optionally also suitable for adjusting the cell structure. Mention may be made, for example, of emulsifiers, such as castor oil sulfates or sodium salts of fatty acids and salts of fatty acids with amines, such as diethylamine oleate, diethanolamine stearate, diethanolamine ricinoleate, sulfonates, such as alkali metal or ammonium salts of dodecylbenzene or dinaphthylmethanedisulfonic acid and ricinoleic acid; foam stabilizers, such as siloxane-oxyalkylene copolymers and other organopolysiloxanes, ethoxylated alkylphenols, ethoxylated fatty alcohols, paraffin oils, castor oil esters or ricinoleic acid esters, turkey red oil and peanut oil, and cell regulators, such as paraffins, fatty alcohols and dimethylpolysiloxanes. Oligomeric polyacrylates with polyoxyalkylene and fluoroalkane groups as side groups are also suitable for improving the emulsification, cell structure and / or stability of the foam.

[0217] Suitable mold release agents include, for example, reaction products of fatty acid esters with polyisocyanates, salts of amino-containing polysiloxanes and fatty acids, salts of saturated or unsaturated (cyclo)aliphatic carboxylic acids having at least 8 carbon atoms and tertiary amines, and in particular internal mold release agents, such as carboxylic acid esters and / or carboxamides prepared by esterification or amidation of a mixture of montanic acid and at least one aliphatic carboxylic acid having at least 10 carbon atoms with at least difunctional alkanolamines, polyols and / or polyamines having a molecular weight of 60 to 400, mixtures of organic amines, mixtures of metal salts of stearic acid and organic mono- and / or dicarboxylic acids or their anhydrides or imino compounds, metal salts of carboxylic acids and optionally carboxylic acids.

[0218] Fillers, in particular reinforcing fillers, are understood to mean customary organic and inorganic fillers, reinforcing agents, weighting agents, agents for improving the wear behavior in paints, coating compositions, etc., which substances are known per se. Specific examples which may be mentioned are: inorganic fillers, for example siliceous minerals, for example sheet silicates, for example antigorite, bentonite, serpentine, hornblende, amphibole, chrysotile, talc; metal oxides, such as kaolin, aluminum oxide, titanium oxide, zinc oxide and iron oxide; metal salts, such as chalk, barite; and inorganic pigments, such as cadmium sulfide, zinc sulfide and glass, etc. Preference is given to using kaolin (china clay), aluminum silicate and coprecipitates of barium sulfate with aluminum silicate, and also natural and synthetic fibrous minerals, such as wollastonite, metal fibers and in particular glass fibers of various lengths, which may optionally have been sized. Examples of organic fillers that can be used include carbon black, melamine, rosin, cyclopentadiene-based resins and graft polymers, and also cellulose fibers, polyamide fibers, polyacrylonitrile fibers, polyurethane fibers, polyester fibers based on aromatic and / or aliphatic dicarboxylic acid esters, and in particular carbon fibers.

[0219] The inorganic filler and the organic filler may be used alone or in the form of a mixture.

[0220] In the composite material according to the invention, the volume proportion of the foam particles is preferably more than 20% by volume, more preferably more than 50% by volume, more preferably more than 80% by volume and in particular more than 90% by volume, in each case based on the volume of the composite system according to the invention.

[0221] The composite material of the invention, in particular a composite material having a matrix consisting of porous polyurethane, is characterized in that the matrix material has very good adhesion to the foam pellets of the invention. Therefore, at the interface between the matrix material and the foam pellets, the composite material of the invention preferably does not have tearing. This enables the preparation of composite materials that have improved mechanical properties, such as tear propagation resistance and elasticity, at the same density compared to conventional polymer materials, in particular conventional polyurethane materials.

[0222] The elasticity of the composite material according to the invention in the form of integral foam is preferably greater than 40%, particularly preferably greater than 50%, according to DIN 53512.

[0223] Furthermore, the composite materials of the invention, especially those based on integral foams, have high resilience at low density. Therefore, integral foams based on the composite materials of the invention are particularly well suited as materials for shoe soles. Thus, light and comfortable shoe soles with good durability are obtained. Such materials are particularly suitable as midsoles for sports shoes.

[0224] The composite material having a porous matrix of the present invention is suitable for use, for example, in cushioning components for furniture and mattresses.

[0225] Composite materials having a matrix consisting of a viscoelastic gel have in particular increased viscoelasticity and improved resilience properties. Therefore, these materials are also suitable as cushioning materials, for example for seats, in particular saddles, such as bicycle saddles or motorcycle saddles.

[0226] Composite materials with a dense matrix are suitable, for example, as floor coverings, in particular for coverings for playgrounds, athletic fields, sports fields and gymnasiums.

[0227] Depending on the polymer (PM) used, the properties of the composite material according to the invention can be varied within wide ranges, in particular by varying the size, shape and properties of the expanded pellets or by adding other additives, for example other non-foamed pellets (e.g. plastic pellets, for example rubber pellets).

[0228] The composite material of the invention has high durability and toughness, which is particularly evident from the high tensile strength and elongation at break. In addition, the composite material of the invention has a low density.

[0229] Further embodiments of the invention can be found in the claims and the examples. It is to be understood that the features of the subject matter / method / use of the invention mentioned above and described below can be used not only in the combination specified in each case, but also in other combinations without departing from the scope of the invention. For example, combinations of preferred features with particularly preferred features or combinations of features not further characterized with particularly preferred features etc. are therefore also implicitly covered, even if such combinations are not explicitly mentioned.

[0230] Exemplary embodiments of the present invention are listed below, but these do not limit the present invention. In particular, the present invention also includes those embodiments resulting from the dependencies and combinations specified below.

[0231] 1. A method for preparing thermoplastic polyurethane, comprising at least steps (i) and (ii):

[0232] (i) converting at least one isocyanate composition (ZI) and a polyol composition (ZP) to obtain a prepolymer having isocyanate groups, the isocyanate composition comprising an isocyanate (l1) selected from the group consisting of naphthylene 1,5-diisocyanate (NDI), diphenylmethane 4,4'-diisocyanate (MDI), p-phenylene diisocyanate (PPDI) and o-toluene diisocyanate (TODI), ethylene diphenyl diisocyanate (EDI) or mixtures thereof, and the polyol composition comprising polytetrahydrofuran or a derivative thereof,

[0233] (ii) reacting the prepolymer obtained in step (i) with at least one chain extender (KV).

[0234] 2. The method according to embodiment 1, wherein the derivative of polytetrahydrofuran is poly-ε-caprolactone polyol.

[0235] 3. The method according to any one of embodiments 1 and 2, wherein the other components used in the reaction of step (ii) are selected from polyols, chain extenders, catalysts, cell nucleating agents, other auxiliaries and additives.

[0236] 4. The process according to any one of embodiments 1 to 3, wherein the poly-ε-caprolactone polyol is obtainable or obtained by reacting ε-caprolactone with a starter molecule selected from polytetrahydrofuran having a number average molecular weight of 500 to 2500 g / mol.

[0237] 5. The process according to any one of embodiments 1 to 4, wherein the poly-ε-caprolactone polyol is obtainable or obtained by reacting ε-caprolactone with a starter molecule selected from α-hydro-ω-hydroxypoly(oxytetramethylene) glycol.

[0238] 6. The method of any one of embodiments 1 to 5, wherein the polyol composition comprises α-hydro-ω-hydroxy poly(oxytetramethylene) polyol in an amount of 0.1 wt % to 50 wt %, based on the polyol composition.

[0239] 7. The method according to any one of embodiments 1 to 6, wherein the polyisocyanate composition comprises naphthylene 1,5-diisocyanate (NDI) in an amount of 90 wt % to 100 wt %, based on the total polyisocyanate composition.

[0240] 8. The process according to any one of embodiments 1 to 7, wherein the chain extender (KV) is selected from diols having a molecular weight of 50 to 500 g / mol and diamines having a molecular weight of 50 to 500 g / mol.

[0241] 9. The process according to any one of embodiments 1 to 8, wherein the chain extender (KV) is selected from MEG, butane-1,4-diol, propane-1,3-diol, hexane-1,6-diol, 2-ethylhexane-1,3-diol or 2-butyl-2-ethylpropanediol.

[0242] 10. A thermoplastic polyurethane obtainable or obtained by a process comprising at least steps (i) and (ii):

[0243] (i) converting at least one isocyanate composition (ZI) and a polyol composition (ZP) to obtain a prepolymer having isocyanate groups, the isocyanate composition comprising an isocyanate (l1) selected from the group consisting of naphthylene 1,5-diisocyanate (NDI), diphenylmethane 4,4'-diisocyanate (MDI), p-phenylene diisocyanate (PPDI) and o-toluene diisocyanate (TODI), ethylene diphenyl diisocyanate (EDI) or mixtures thereof, and the polyol composition comprising polytetrahydrofuran or a derivative thereof,

[0244] (ii) reacting the prepolymer obtained in step (i) with at least one chain extender (KV).

[0245] 11. The thermoplastic polyurethane according to embodiment 10, wherein the derivative of polytetrahydrofuran is poly-ε-caprolactone polyol.

[0246] 12. The thermoplastic polyurethane according to any one of embodiments 10 and 11, wherein the other components used in the reaction of step (ii) are selected from polyols, chain extenders, catalysts, cell nucleating agents, other auxiliary agents and additives.

[0247] 13. Thermoplastic polyurethane according to any one of embodiments 10 to 12, wherein the poly-ε-caprolactone polyol is obtainable or obtained by reacting ε-caprolactone with a starter molecule selected from polytetrahydrofuran having a number average molecular weight of 500 to 2500 g / mol.

[0248] 14. Thermoplastic polyurethane according to any one of embodiments 10 to 13, wherein the poly-ε-caprolactone polyol is obtainable or obtained by reacting ε-caprolactone with a starter molecule selected from α-hydro-ω-hydroxypoly(oxytetramethylene) glycol.

[0249] 15. The thermoplastic polyurethane according to any one of embodiments 10 to 14, wherein the polyol composition comprises α-hydro-ω-hydroxy poly(oxytetramethylene) polyol in an amount of 0.1 wt % to 50 wt %, based on the polyol composition.

[0250] 16. The thermoplastic polyurethane according to any one of embodiments 10 to 15, wherein the polyisocyanate composition comprises naphthylene 1,5-diisocyanate (NDI) in an amount of 90% to 100% by weight, based on the total polyisocyanate composition.

[0251] 17. Thermoplastic polyurethane according to any one of embodiments 10 to 16, wherein the chain extender (KV) is selected from diols having a molecular weight of 50 to 500 g / mol and diamines having a molecular weight of 50 to 500 g / mol.

[0252] 18. Thermoplastic polyurethane according to any one of embodiments 10 to 17, wherein the chain extender (KV) is selected from MEG, butane-1,4-diol, propane-1,3-diol, hexane-1,6-diol, 2-ethylhexane-1,3-diol or 2-butyl-2-ethylpropanediol.

[0253] 19. A foam pellet comprising a thermoplastic polyurethane obtainable or obtained by the process according to any one of embodiments 1 to 9 or a thermoplastic polyurethane according to any one of embodiments 10 to 18.

[0254] 20. Use of a thermoplastic polyurethane obtainable or obtained by a process according to any one of embodiments 1 to 9 or a thermoplastic polyurethane according to any one of embodiments 10 to 18 for preparing moldings or bead foams.

[0255] 21. A method for preparing foam pellets comprising the thermoplastic polyurethane according to embodiments 10 to 18, wherein the polyurethane is impregnated with a blowing agent in an extruder, the impregnated polyurethane is cut into pellets, and the pellets are expanded immediately after cutting to obtain expanded thermoplastic polyurethane beads.

[0256] 22. A method for preparing foam pellets comprising the thermoplastic polyurethane according to any one of embodiments 10 to 18, comprising steps (a) to (c):

[0257] (a) providing a thermoplastic polyurethane in the form of beads in the form of pellets of suitable geometry,

[0258] (b) impregnating the pellets with a blowing agent under pressure and temperature in a tank or autoclave,

[0259] (c) The tank is spontaneously depressurized, producing foam beads as the pressure drops and the blowing agent dissolved in the pellets expands.

[0260] 23. The method according to embodiment 22, wherein in step (b) the pellets are impregnated with 0.1 wt% to 50 wt% of a blowing agent at a temperature of 90 to 180°C and a pressure of 0.5 to 10 MPa.

[0261] 24. Foam pellets obtained by the process according to any one of embodiments 21 to 23.

[0262] 25. Foam pellets according to embodiment 24, wherein the average diameter of the beads is from 0.5 to 20 mm.

[0263] 26. Mouldings obtainable from the foam pellets according to any one of embodiments 24 and 25.

[0264] 27. A method for preparing a molded article from foam pellets according to any one of embodiments 24 and 25, comprising steps (a) and (b):

[0265] (a) introducing expanded thermoplastic polyurethane beads into a mold;

[0266] (b) contacting the expanded thermoplastic polyurethane beads introduced into the mold with steam, hot air or high-energy radiation so that the expanded thermoplastic polyurethane beads are melted and welded on the surface to form a molded product.

[0267] 28. Foam pellets according to embodiment 19, wherein the average diameter of the beads is from 0.5 to 20 mm.

[0268] 29. Mouldings obtainable from the foam pellets according to any one of embodiments 19 and 28.

[0269] 30. Use of the foam bead material according to any of embodiments 19 and 28 for producing a molding.

[0270] 31. The use according to embodiment 30, wherein the molding is produced by fusing or bonding beads to one another.

[0271] 32. The use according to embodiment 30 or 31, wherein the molded article is a shoe sole, a shoe sole component, a mattress, a liner, a grip, a protective film, an automotive interior or exterior component, a gymnastics mat, a body protector, a decorative element in automobile construction, a sound insulation material, a vibration damper, a cushioning element, a bicycle saddle, a toy, a tire or a tire component, or a covering for athletic surfaces, gymnasiums or paths, a vibration damping layer or a vibration damping core in a sandwich element, or a packaging.

[0272] 33. Use of the foam granules according to any of embodiments 19 and 28 in balls and sports equipment or as floor coverings and sidings, in particular for playing field surfaces, athletic field surfaces, sports halls, children's playgrounds and paths.

[0273] 34. A composite material comprising a matrix consisting of a polymer (PM) and foam pellets according to any one of embodiments 19 and 28.

[0274] 35. A method for preparing a thermoplastic polyurethane, comprising at least steps (i) and (ii):

[0275] (i) converting at least one isocyanate composition (ZI) and a polyol composition (ZP) to obtain a prepolymer having isocyanate groups, the isocyanate composition comprising an isocyanate (I1) selected from the group consisting of naphthylene 1,5-diisocyanate (NDI), p-phenylene diisocyanate (PPDI) and o-toluene diisocyanate (TODI), ethylene diphenyl diisocyanate (EDI) or mixtures thereof, and the polyol composition (ZP) comprising polytetrahydrofuran or a derivative thereof,

[0276] (ii) reacting the prepolymer obtained in step (i) with at least one chain extender (KV).

[0277] 36. The method of claim 35, wherein the derivative of polytetrahydrofuran is poly-ε-caprolactone polyol.

[0278] 37. The method according to any one of claims 35 and 36, wherein the other components used in the reaction of step (ii) are selected from polyols, chain extenders, catalysts, cell nucleating agents, other auxiliary agents and additives.

[0279] 38. The process according to any one of claims 35 to 37, wherein the poly-ε-caprolactone polyol is obtainable or obtained by reacting ε-caprolactone with a starter molecule selected from α-hydro-ω-hydroxypoly(oxytetramethylene) glycol.

[0280] 39. The method according to any one of claims 35 to 38, wherein the polyisocyanate composition comprises naphthylene 1,5-diisocyanate (NDI) in an amount of 90 to 100 wt. %, based on the total polyisocyanate composition.

[0281] 40. The process according to any one of claims 35 to 39, wherein the chain extender (KV) is selected from diols having a molecular weight of 50 to 500 g / mol and diamines having a molecular weight of 50 to 500 g / mol.

[0282] 41. The process according to any one of claims 35 to 40, wherein the chain extender (KV) is selected from MEG, butane-1,4-diol, propane-1,3-diol, hexane-1,6-diol, 2-ethylhexane-1,3-diol or 2-butyl-2-ethylpropanediol.

[0283] 42. A thermoplastic polyurethane obtainable or obtained by a process comprising at least steps (i) and (ii):

[0284] (i) converting at least one isocyanate composition (ZI) and a polyol composition (ZP) to obtain a prepolymer having isocyanate groups, the isocyanate composition comprising an isocyanate (I1) selected from the group consisting of naphthylene 1,5-diisocyanate (NDI), p-phenylene diisocyanate (PPDI) and o-toluene diisocyanate (TODI), ethylene diphenyl diisocyanate (EDI) or mixtures thereof, and the polyol composition (ZP) comprising polytetrahydrofuran or a derivative thereof,

[0285] (ii) reacting the prepolymer obtained in step (i) with at least one chain extender (KV).

[0286] 43. Foam pellets comprising a thermoplastic polyurethane obtainable or obtained by a process according to any one of claims 35 to 41 or a thermoplastic polyurethane according to claim 42.

[0287] 44. Foam pellets according to claim 43, wherein the average diameter of the beads is from 0.5 to 20 mm.

[0288] 45. A moulding obtainable from the foam bead material according to any one of claims 43 and 44.

[0289] 46. ​​Use of the foam bead material according to any one of claims 43 and 44 for producing moldings.

[0290] 47. The use according to claim 46, wherein the molding is produced by fusing or bonding the beads to one another.

[0291] 48. The use according to claim 46 or 47, wherein the molded article is a shoe sole, a shoe sole component, a mattress, a liner, a grip, a protective film, an automotive interior or exterior component, a gymnastics mat, a body protector, a decorative element in automobile construction, a sound insulation material, a vibration damper, a cushioning element, a bicycle saddle, a toy, a tire or a tire component, or a covering for athletic surfaces, sports halls or paths, a vibration damping layer or a vibration damping core in a sandwich element, or a packaging.

[0292] 49. Use of foam granules according to any of claims 43 and 44 in balls and sports equipment or as floor coverings and sidings, in particular for playing field surfaces, athletic field surfaces, sports fields, children's playgrounds and paths.

[0293] 50. A composite material comprising a matrix consisting of a polymer (PM) and foam pellets according to any one of claims 43 and 44.

[0294] 51. A method for preparing a thermoplastic polyurethane, comprising at least steps (i) and (ii):

[0295] (i) converting at least one polyisocyanate composition (ZI) comprising naphthylene diisocyanate (NDI) as isocyanate (I1) and a polyol composition (ZP) comprising polytetrahydrofuran or a derivative thereof to obtain a prepolymer having isocyanate groups,

[0296] (ii) reacting the prepolymer obtained in step (i) with at least one chain extender (KV).

[0297] 52. The method of claim 51, wherein the derivative of polytetrahydrofuran is poly-ε-caprolactone polyol.

[0298] 53. The method according to any one of claims 51 and 52, wherein the other components used in the reaction of step (ii) are selected from polyols, chain extenders, catalysts, cell nucleating agents, other auxiliary agents and additives.

[0299] 54. The process according to any one of claims 51 to 53, wherein the poly-ε-caprolactone polyol is obtainable or obtained by reacting ε-caprolactone with a starter molecule selected from α-hydro-ω-hydroxypoly(oxytetramethylene) glycol.

[0300] 55. The method of any one of claims 51 to 54, wherein the polyisocyanate composition comprises naphthylene 1,5-diisocyanate (NDI) in an amount of 90 to 100 wt%, based on the total polyisocyanate composition.

[0301] 56. The process according to any one of claims 51 to 55, wherein the chain extender (KV) is selected from diols having a molecular weight of 50 to 500 g / mol and diamines having a molecular weight of 50 to 500 g / mol.

[0302] 57. The process according to any one of claims 51 to 56, wherein the chain extender (KV) is selected from MEG, butane-1,4-diol, propane-1,3-diol, hexane-1,6-diol, 2-ethylhexane-1,3-diol or 2-butyl-2-ethylpropanediol.

[0303] 58. A thermoplastic polyurethane obtainable or obtained by a process comprising at least steps (i) and (ii):

[0304] (i) converting at least one polyisocyanate composition (ZI) comprising naphthylene diisocyanate (NDI) as isocyanate (I1) and a polyol composition (ZP) comprising polytetrahydrofuran or a derivative thereof to obtain a prepolymer having isocyanate groups,

[0305] (ii) reacting the prepolymer obtained in step (i) with at least one chain extender (KV).

[0306] 59. Foam pellets comprising a thermoplastic polyurethane obtainable or obtained by a process according to any one of claims 51 to 57 or a thermoplastic polyurethane according to claim 58.

[0307] 60. Foam pellets according to claim 59, wherein the average diameter of the beads is from 0.5 to 20 mm.

[0308] 61. A moulding obtainable from foam pellets according to any one of claims 59 and 60.

[0309] 62. Use of the foam pellets according to any one of claims 59 and 60 for producing moldings.

[0310] 63. The use according to claim 62, wherein the molding is produced by fusing or bonding beads to one another.

[0311] 64. The use according to claim 62 or 63, wherein the molded article is a shoe sole, a shoe sole component, a mattress, a liner, a grip, a protective film, an automotive interior or exterior component, a gymnastics mat, a body protector, a decorative element in automobile construction, a sound insulation material, a vibration damper, a cushioning element, a bicycle saddle, a toy, a tire or a tire component, or a covering for athletic surfaces, gymnasiums or paths, a vibration damping layer or a vibration damping core in a sandwich element, or a packaging.

[0312] 65. Use of foam granules according to any of claims 59 and 60 in balls and sports equipment or as floor coverings and sidings, in particular for playing field surfaces, athletic field surfaces, sports fields, children's playgrounds and paths.

[0313] 66. A composite material comprising a matrix consisting of a polymer (PM) and foam pellets according to any one of claims 59 and 60.

[0314] The following examples serve to illustrate the invention but are in no way limiting to the subject matter of the invention. Example

[0315] 1. Preparation Example of Thermoplastic Polyurethane

[0316] 1.1 Experiment 1 (TPU 1)

[0317] 1000 parts by weight of polyol (PTHF terminated with PCL (PCL500-PTHF1000-PCL500), PTHF2000 4:1) were heated to a temperature of 130-160°C, 200 parts by weight of NDI were added in solid form and reacted. After a reaction time of 30-50 minutes in a temperature range of 150-90°C, a prepolymer having an NCO content of 3.2% and a viscosity of 2500 mPas was obtained at 90°C.

[0318] Within 2 hours after the preparation, 100 parts by weight of the prepolymer thus obtained were uniformly mixed with 3.4 parts by weight of butane-1,4-diol at a temperature of 90°C and introduced into a mold at a mold temperature of 80-100°C.

[0319] After a curing time of 20-30 minutes, the material was heat treated at 110°C for 14 hours and the resulting material could be further processed by injection molding.

[0320] The obtained TPU 1 was pelletized by a grinder and converted into lenticular particles by underwater pelletization by extrusion using a ZSK40 twin-screw extruder with a maximum zone temperature of 220° C. and a porous plate temperature of 230° C. The TPU was then dried at 80° C. for 15 hours.

[0321] 1.2 Experiment 2 (TPU 2)

[0322] 1000 parts by weight of polyol (PTHF terminated with PCL, PTHF2000 4:1) were heated to a temperature of 130-160°C, 200 parts by weight of NDI were added in solid form and reacted. After a reaction time of 30-50 minutes in a temperature range of 150-90°C, a prepolymer having an NCO content of 2.87% and a viscosity of 2960 mPas was obtained at 90°C.

[0323] Within 4 hours after preparation, 100 parts by weight of the prepolymer thus obtained were uniformly mixed with 2.73 parts by weight of a mixture consisting of 100 parts of propane-1,3-diol and 5 parts of an amine catalyst mixture (65% N-methyl-N-dimethylaminoethylpiperazine and 35% pentamethyldiethylenetriamine) at a temperature of 90° C. and introduced into a mold having a mold temperature of 80-100° C.

[0324] After a curing time of 20-30 minutes, the material was heat treated at 110°C for 14 hours and the resulting material could be further processed by injection molding.

[0325] In subsequent reprocessing to produce lenticular particles, talc was added at a concentration of 0.05%.

[0326] 1.3 Determination method of NCO content:

[0327] plan:

[0328] Di-n-hexylamine solution: 166.8 g of di-n-hexylamine was prepared into 1.0 L (in a 1 L volumetric flask) with xylene and homogenized.

[0329] 1% Bromophenol Blue Solution: Dissolve 0.5 g of bromophenol blue in 49.5 g of ethanol and transfer to a pipette bottle.

[0330] step:

[0331] Dispense 10 mL of the amine solution into a conical flask. Subsequently, add 20 mL of chlorobenzene. For an expected isocyanate content of 4%, weigh 2 g-2.5 g of prepolymer to the nearest 0.1 mg (the weighing of other isocyanate concentrations must be adjusted accordingly). After complete dissolution (visual inspection), add 50 mL of methanol. After adding 3 drops of bromophenol blue solution, the unconsumed amine is then back-titrated with HCl (c=1.0 mol / L) until the color changes from blue to yellow.

[0332] Blank samples (ie, samples containing no prepolymer) were treated in the same manner - except that no samples were weighed.

[0333] Calculation: Free NCO = (((V BLK –V 样品 )*M*c*t) / m)*100%

[0334] Among them, V BLK = Consumption of HCl (1.0 mol / L) in blank sample, in L

[0335] V sample = Consumption of HCl (1.0 mol / L) in the sample, in L

[0336] M = molar mass of NCO 42.02 g / mol

[0337] C = molar concentration of HCl 1.9 mol / L

[0338] t=HCl titration (1.0mol / L)

[0339] m = sample weight of prepolymer in grams

[0340] 1.4 Example 3 (TPU 3) - Reactive Extruder

[0341] a. Continuous Synthesis Example

[0342] NDI and any solid additives are fed into the first barrel of a ZSK32 MC twin-screw extruder from Coperin with a processing length of 56D. Polyols heated to 160°C as well as catalysts and any liquid additives are fed into the molten NDI in the second barrel. After mixing and (partial) reaction of the components, the chain extender is added downstream in the fifth zone. The reaction components are converted at barrel temperatures of 190-220°C with conversions of up to >95%. After synthesis, the resulting polymer melt is pelletized underwater and the resulting pellets are dried.

[0343] As a variant of the above-described method, all liquid components can also be added to zone 2 .

[0344]

[0345]

[0346] 2. Test method:

[0347] Test methods / specifications used to characterize the pellets used and the resulting foam beads and molded articles include the following:

[0348] a. Melting point determination by DSC

[0349] Using a DSC Q100 from TA Instruments, the method according to ISO 11357-3 (German version 04.01.2013). To determine the melting point of the thermoplastic elastomer used or the other thermoplastic elastomers of the invention, 3-5 mg in pellet form were heated in a first run between 20° C. and 200° C. at a heating rate of 20° C. / min, then cooled to 20° C. at 10° C. / min, followed by another heating cycle (second run) at a heating rate of 10° C. / min. The melting point recorded is the peak maximum temperature in the second run.

[0350] b. Bulk density

[0351] The determination is carried out in accordance with DIN EN ISO 60:2000-1. Here, the foam beads are introduced into a measuring cylinder of known volume using a funnel of fixed geometry (completely filled with bulk material), the excess bulk material is leveled out of the cylinder using a straight-edged rod, and the content of the cylinder is determined by weighing.

[0352] The funnel used was 40 cm high, with an opening angle of 35° and an outlet diameter of 50 mm. The inner diameter of the graduated cylinder used was 188 mm and the volume was 10 L.

[0353] Bulk density (SD) is calculated from the mass of the material bed [kg] / 0.01 [m 3 ].

[0354] The bulk density reported is the average of 3 measurements in kg / m 3 count.

[0355] c. Average cell density

[0356] The foam structure was evaluated by visual image analysis using a PORE! SCAN Advanced Plus from Goldlücke Ingenieurleistungen. For this purpose, 10 foam beads were divided in half in each case and the cross-sectional area was measured each time. In the case of non-spherical (e.g. elongated, cylindrical or elliptical) foam beads, the division was in the direction of the longest dimension.

[0357] The average cell density is the ratio of the number of cells in a cross-sectional area to the cross-sectional area and is expressed in 1 / mm 2 Record.

[0358] The values ​​are categorized as follows:

[0359]

[0360] d. Densification level VG

[0361] The densification level VG is the ratio of the molded density (FT density) to the bulk density (SD). VG = FT density [kg / m 3 ] / SD[kg / m 3 ].

[0362] e. Other test methods:

[0363] Other testing methods used for material characterization may include the following: DMA, TMA, NMR, FT-IR, GPC

[0364]

[0365] 3. Preparation of Foam Beads by Impregnation in Autoclave

[0366] 3.1 Raw materials

[0367] For E-TPU Examples 1 to 7 (and Comparative Examples), the following TPU materials were used:

[0368] Density (20kg / m 3 )

[0369] TPU in the form of lens-shaped pellets 1 1150kg / m 3

[0370] TPU in the form of lenticular pellets 2 1150kg / m 3

[0371] The experiments were carried out at a tank filling level of 80% and compared Here, the ratio is defined as the ratio of the mass of the pellets to the suspension medium (water in the examples).

[0372] 3.2 General Preparation Method of E-TPU Example 1 to E-TPU Example 7

[0373] 100 parts by weight (corresponding to 27.1% by weight, based on the total suspension without blowing agent) of granules, 262 parts by weight (corresponding to 71.0% by weight, based on the total suspension without blowing agent) of water, 6.7 parts by weight (corresponding to 1.8% by weight, based on the total suspension without blowing agent) of calcium carbonate (suspension aid), 0.13 parts by weight (corresponding to 0.04% by weight, based on the total suspension without blowing agent) of a surface-active substance (Lutensol AT 25; suspension aid) and the appropriate amount of butane as blowing agent (based on the amount of granules) were heated with stirring.

[0374] Nitrogen is then additionally injected into the liquid phase at 50° C. and the internal pressure is adjusted to a predetermined pressure (800 kPa). Then, when the impregnation temperature (IMT) is reached and optionally while observing the holding time (HZ) and at the impregnation pressure (IMP) finally established, expansion is carried out by means of an expansion device. At this point, the gas space is adjusted to a fixed discharge pressure (AP) and remains constant during the expansion process. The expansion jet downstream of the expansion device can optionally be cooled with water at a specific volume flow rate at a specific temperature (water quenching).

[0375] The holding time defines the time during which the liquidus temperature is within the temperature range of 5°C below the immersion temperature to 2°C above the immersion temperature.

[0376] After removal of the suspension medium / suspension aid system (dispersant / surfactant) and drying, the bulk density (SD) of the resulting foam beads was measured.

[0377] The exact preparation parameters and bulk density of the resulting batches (foam beads) are listed in Tables 1a and 1b.

[0378] Table 1a: Experimental parameters of Examples 1 to 7

[0379]

[0380] Table 1b: Experimental parameters of Examples 1 to 7

[0381]

[0382] 1 :The cell structure of the foam pellets contains bubbles and cracks

[0383] 4. Preparation of molded parts

[0384] The foam beads (expanded pellets) are subsequently welded in a molding machine from Kurtz Ersa GmbH (Energy Foamer K68) to give square plates with a side length of 200 mm and a thickness of 10 mm and 20 mm, or in a molding machine from Erlenbach (EHV-C870 / 670) by contact with steam to give rectangular plates with a side length of 300x200 mm and a thickness of 10 mm.

[0385] The molded parts can be produced by a pressure filling method or a crack filling method. For the examples of the present invention, the crack filling method was used (see Table 2).

[0386] After preparation, the molded parts were stored at 60° C. to 70° C. for 4 to 16 hours, and then the density of the molded parts was tested (Table 2).

[0387] Table 2: Steam pressure and time for welding materials in Examples and Comparative Examples

[0388]

[0389]

[0390] KV no welding / no FT preparation possible,

[0391] nd Not determined

[0392] The results of the molded part tests are listed in Table 3.

[0393] Table 3

[0394]

[0395] nd Not determined

[0396] 5. Preparation Example of Composite Material

[0397] 5.1 General preparation methods of composite materials

[0398] The beads prepared above are used to prepare molded parts by means of PU systems or adhesives. For this purpose, the liquid formulation is first prepared, which is then mixed vigorously with the beads in a plastic container made of polyethylene and then discharged into the mold. The mold used is a Teflon-coated wooden mold with internal dimensions of 4.5x4.5x4.5cm. By means of an inlay of 4.5x4.5x2.5cm, a cube or a flat plate with a thickness of 2cm can be prepared from the formulation.

[0399] 5.2 Raw materials

[0400] Beads used: E-TPU1

[0401] 5.3 Foam systems and adhesives

[0402] A Composition

[0403] 94 copies

[0404]

[0405]

[0406] B Composition

[0407] 100 parts Iso137 / 28 (NCO[%] 18.00)

[0408]

[0409] 5.4 Gel system

[0410] A Composition

[0411] 100 copies

[0412]

[0413] B Composition

[0414] 11 servings

[0415] Name Weight %

[0416] Hexamethylene diisocyanate 100

[0417] 5.5 Results

[0418]

[0419] 6. Preparation of eTPU / PU foam composite sheets

[0420] With the aid of a dosing machine (4K TPY NDF 20-4 low-pressure machine from Elastogran GmbH), component A preheated to 40° C. and component B preheated to 25° C., whose composition is listed in Table 4, were added to the appropriate amount of E-TPU in a 2.7 L plastic beaker under a pressure of 16 bar under time control according to the details in Table 4.

[0421] Table 4: Composition of A and B components

[0422]

[0423] The batching parameters are based on the fact that during the mixing and transfer of E-TPU and foam, the total mass of the foam system loses about 10%. This is adjusted by weighing the density to 300 (PU foam 1) or 260 kg / m3 Finished test sheets of (PU foam 2) were used for inspection.

[0424] Table 5: Time-based dosing of the dosing machine used (E-TPU 1)

[0425]

[0426] Immediately thereafter, the components and the E-TPU were mixed with the aid of a laboratory stirrer (model EWTHV-05 from Vollrath GmbH) for a maximum of 10 s, then introduced with a wooden spatula and evenly distributed in an open aluminum mold with dimensions of 20x20x1 cm or 20x20x2 cm, which had been preheated to 45° C. and coated with silicone (marbo super release agent), until a gel time of about 40 s was reached. The aluminum mold was heated using an SC100 heating device from Thermo Scientific.

[0427] After the mold is closed, the system reacts for 30 minutes until completion. Here, the ventilation of the mold is controlled by ventilation channels, while the mold temperature is kept constant at 45°C.

[0428] Before the test sheets were tested, they were stored at room temperature for at least 2 days to ensure that the PU foam had reacted completely. The table lists the resilience (also called rebound) according to DIN 53512:2000-04 and the density according to DIN EN ISO 845:2009-10 of the resulting 20 mm sheets.

[0429] Table 6: Measured density and resilience of the obtained composite sheets

[0430] name <![CDATA[Density [kg / m 3 > Resilience [%] Complex 1 300 77 Complex 2 300 77 Complex 3 260 71 Complex 4 260 74

[0431] PU foam 3 was processed in the same way as foams 1 and 2 with low-level catalysis and introduced at a bead mass ratio of 70%. Due to the faster reaction time, PU foam 4 was introduced directly into the mold filled with E-TPU, around which the foam was subsequently formed. The fully filled mold allowed a bead mass ratio of about 50%. The faster-reacting system achieved a demoulding time of about 5 minutes. All other processing parameters remained unchanged.

[0432] The following mechanical test data were determined on test sheets 20 mm thick.

[0433] Table 7: Test results of composite sheet PU foam 3 and 4

[0434]

[0435] References:

[0436] WO 94 / 20568A1

[0437] WO 2007 / 082838 A1

[0438] WO 2017 / 030835 A1

[0439] WO 2013 / 153190 A1

[0440] WO 2010 / 010010 A1

[0441] “Plastics Handbook”, volume 7, “Polyurethanes”, Carl Hanser Verlag, 3rd edition, 1993, chapter 3.1

[0442] Saechtling (ed.), Plastics Paperback, 27th edition, Hanser-Verlag, Munich 1998, chapters 3.2.1 and 3.2.4

[0443] WO 2014 / 150122 A1

[0444] WO 2014 / 150124 A1

[0445] EP 1979401 B1

[0446] US 20150337102 A1

[0447] EP2872309B1

[0448] EP 3053732 A

[0449] WO 2016 / 146537 A1

[0450] “Plastics Handbook”, volume 7, “Polyurethanes”, Carl Hanser Verlag, 3rd edition, 1993, chapter 3

[0451] "Integral Foam", Carl-Hanser-Verlag, Munich, Vienna, 1975, or in Kunststoff-Handbuch, volume 7, Polyurethane, 3rd edition, 1993, chapter 7

Claims

1. A foam pellet comprising a thermoplastic polyurethane obtainable or obtained by a process comprising at least steps (i) and (ii): (i) converting at least one isocyanate composition (ZI) and a polyol composition (ZP) to obtain a prepolymer having isocyanate groups, the isocyanate composition comprising an isocyanate (l1) selected from the group consisting of naphthylene 1,5-diisocyanate (NDI), diphenylmethane 4,4'-diisocyanate (MDI), p-phenylene diisocyanate (PPDI) and o-toluene diisocyanate (TODI), ethylene diphenyl diisocyanate (EDI) or mixtures thereof, and the polyol composition comprising polytetrahydrofuran and its derivatives; (ii) reacting the prepolymer obtained in step (i) with at least one chain extender (KV), wherein the derivative is a poly-ε-caprolactone polyol obtained by reacting ε-caprolactone with polytetrahydrofuran as a starting molecule, and The foam pellets are prepared by a method comprising the following steps: (a) providing a composition (Z1) comprising a thermoplastic polyurethane; (b) impregnating the composition (Z1) with a blowing agent under pressure; and (c) expanding the composition (Z1) by reducing the pressure.

2. The foam pellets according to claim 1, wherein the other components used in the reaction of step (ii) are selected from polyols, chain extenders, catalysts, cell nucleating agents, and other additives.

3. The foam pellets according to claim 1 or 2, wherein the isocyanate composition comprises naphthylene 1,5-diisocyanate (NDI) in an amount of 90% to 100% by weight, based on the total isocyanate composition.

4. Foam pellets according to claim 1 or 2, wherein the chain extender (KV) is selected from diols having a molecular weight of 50 to 500 g / mol and diamines having a molecular weight of 50 to 500 g / mol.

5. The foam pellets according to claim 1 or 2, wherein the chain extender (KV) is selected from MEG, butane-1,4-diol, propane-1,3-diol, hexane-1,6-diol, 2-ethylhexane-1,3-diol or 2-butyl-2-ethylpropanediol.

6. The foam pellets according to claim 1 or 2, wherein the average diameter of the foam pellets is 0.5 to 20 mm.

7. A molding obtainable from the foam pellets according to any one of claims 1 to 6.

8. Use of the foam pellets according to any one of claims 1 to 6 for producing moldings.

9. The use according to claim 8, wherein the molding is produced by fusing or bonding foam pellets to one another.

10. The method according to claim 8, wherein the molded article is a shoe sole, a mattress, a lining, a grip, a protective film, an automotive interior or exterior component, a gymnastics mat, a sound insulation material, a vibration damper, a cushioning element, a bicycle saddle, a toy, or a covering for a gymnasium or a path, a vibration damping layer or a vibration damping core in a sandwich element, or a packaging.

11. The use according to claim 8 or 9, wherein the molded article is a shoe sole component.

12. The use according to claim 8 or 9, wherein the molded article is a body protector.

13. The use according to claim 8 or 9, wherein the molding is a decorative element in automobile construction.

14. The use according to claim 8 or 9, wherein the molded article is a tire.

15. The use according to claim 8 or 9, wherein the molded article is a tire component.

16. The use according to claim 8 or 9, wherein the molded article is a covering for a track and field surface.

17. Use of the foam granules according to any one of claims 1 to 6 in sports equipment or as floor coverings and wall panels.

18. Use of the foam pellets according to any one of claims 1 to 6 in balls.

19. Use according to claim 17 for sports ground surfaces, children's playgrounds and paths.

20. The use according to claim 17 for athletic field surfaces.

21. The use according to claim 17, for use in a sports stadium.

22. A composite material comprising a matrix consisting of a polymer (PM) and foam pellets according to any one of claims 1 to 6.

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