Expanded thermoplastic polyurethanes for special molding processes

Abstract

The present invention relates to a molded body comprising expanded particles fused using an electromagnetic field, the expanded particles comprising a composition (C1) comprising a thermoplastic elastomer wherein the composition (C1) has a factor JDIE in the range of 0.3 to 3, the factor being defined by the melting point of the composition (C1) and the loss factor tan [delta] of the composition (C1). The invention also relates to a method for producing moulded bodies comprising expanded particles comprising a composition (C1) comprising at least a thermoplastic elastomer, comprising the following steps: loading the expanded particles comprising a composition (C1) into a mould, and fusing the expanded particles containing a thermoplastic elastomer by supplying energy at least partially via an electromagnetic field, wherein the composition (C1) has a factor JDIE in the range of 0.3 to 3. The invention also relates to the use of the molded body in soles, sole parts, midsoles, insoles, damping elements, cushioning elements, pads, grips, floors, mattresses, sporting goods, bicycle saddles, tires and in motor vehicle interior and exterior trim parts.

Description

[0001] The present invention relates to a molded body comprising expanded particles fused using an electromagnetic field, the expanded particles containing a composition (C1), the composition comprising a thermoplastic elastomer, wherein the composition (C1) has a factor JDI E defined by the melting point of the composition (C1) and the loss factor tan delta of the composition (C1) in the range of 0.3 to 3. The present invention further relates to a process for the production of a molded body comprising expanded particles containing a composition (C1), the composition comprising at least a thermoplastic elastomer, the process comprising the steps of loading the expanded particles containing the composition (C1) into a mold and fusing the expanded particles containing a thermoplastic elastomer by at least partially supplying energy via an electromagnetic field, wherein the composition (C1) has a factor JDI E in the range of 0.3 to 3. The present invention further relates to the use of the molded body in shoe soles, shoe sole parts, midsoles, insoles, shock-absorbing elements, cushioning elements, gaskets, grips, floorings, mattresses, sports goods, bicycle saddles, tires and in motor vehicle interior and exterior parts.

[0002] The production of expanded thermoplastic elastomer bead foams using extrusion technology is described in WO 2014 / 198779 A1 without explaining the production of parts from expanded thermoplastic elastomer beads.

[0003] WO 2015 / 052265 also describes the production of expanded beads from thermoplastic elastomeric polymers using autoclave impregnation of a dense material. The impregnated beads can then be foamed and in special cases directly molded into parts by reducing the pressure in the autoclave. In another possibility, the impregnated beads are removed and heated to the foaming temperature in a separate machine. In the case of obtaining individual foamed beads, the production of parts is not further described.

[0004] Bead foams, such as polypropylene or polystyrene bead foams, are usually fused together in automatic molding machines with superheated water vapor to form shaped parts, for example for the packaging industry. TPU bead foams can be further processed not only by superheated steam fusion but also by in-situ foaming or bonding with reactive polyurethane systems. Since superheated steam fusion has a very high energy requirement, alternatives are sought. Fusion by hot air is in principle possible, but does not yet produce satisfactory parts due to unsatisfactory distribution and requires long cycle times due to the low energy content of hot air and the poor thermal conductivity of closed-cell foams.

[0005] Moulding of expanded thermoplastic polyurethane bead foams is described in DE 10 2013 110 242 A1. Here, different variants of filling the mould are explained, all of which aim at a completely filled cavity. Thus, it is mentioned to fill under pressure or to seal cracks before moulding. In all these variants, the filling is done by pressing more material into the cavity, thus increasing the overall weight and density of the part. With regard to the moulding, steam moulding is used.

[0006] For different expanded thermoplastic beads, the use of electromagnetic radiation or electromagnetic fields to provide energy for moulding is generally described in EP 3 698 949 A1 and WO 2017 / 125410 A1. In particular in WO 2017 / 125410 A1 it is shown that the use of electromagnetic fields to apply energy can result in a uniform foamed part.

[0007] By using electromagnetic fields to improve moulding, a special mould design is described in EP 3 808 522 A1. Here, the mould is split in the cavity to adjust the electromagnetic field and to improve the uniformity of the moulding.

[0008] Foam mouldings comprising expanded thermoplastic polyurethane are widely used in sportswear, shoes and shoe parts and for cushioning elements.

[0009] A way to thermally bond foamed beads together is by high-frequency fusion, as described in particular in WO 2001 / 64414. In high-frequency fusion, foamed beads, in particular expandable polystyrene (EPS), expanded polypropylene (EPP) or expandable polyethylene terephthalate (EPET) to be fused together are surrounded by a liquid medium (e.g. water) that absorbs electromagnetic radiation and then are bonded together by applying a form of electromagnetic radiation (e.g. microwaves). Due to water absorption caused by the higher polarity of thermoplastic polymers, this method is only slightly possible for foamed beads comprising thermoplastic elastomers. In addition, the 100°C temperature that is achievable with boiling water at atmospheric pressure is usually not sufficient to fuse elastomer beads together. Water absorption allows water to penetrate excessively into the beads, and heating is effective not only at the contact points but also within the beads. Thus, the beads can collapse before fusion.

[0010] DE 10 2013 012 515 A1 describes a method to thermally bond foamed beads (in particular EPP or EPS) together by induction heating with an improved energy balance. However, a prerequisite for producing shaped parts by induction heating is to have some electrical conductivity on the bead parts, at least on the surfaces to be bonded together. This can be achieved by coating with an electrically conductive filler such as metal powder or carbon black, nanotubes. Spraying is an example of a possible way to coat the beads.

[0011] WO 2019 / 162172 A1 discloses a method for producing a bead foam from thermoplastic elastomer-based foam beads, which comprises wetting the foam beads with a polar liquid and thermally bonding them together in a mold via high-frequency electromagnetic radiation. The use of additives in the molding process makes the method less efficient and increases the costs.

[0012] WO 2017 / 125410 A1 relates to a method for producing a granular foam part, wherein the foam particles are heated in a mold so that they are fused together. The foam particles are made of polyurethane (PU), polylactide (PLA), polyethylene block amide (PEBA) or from polyethylene terephthalate (PET). Heat is directed to the foam particles by electromagnetic RF radiation. In the case of large or thick granular foam parts, it is described that they are heated more intensively in the central region than at the edge region. An increase in the energy input by the electromagnetic field leads to a complete melting of the foam particles in the central region of the granular foam part.

[0013] The problem addressed by the present invention is to remedy the aforementioned disadvantages and to provide a method for producing a molded body in a simple cost-effective method.

[0014] According to the invention, this problem is solved by a molded body comprising expanded particles fused using an electromagnetic field, the expanded particles containing a composition (C1) comprising a thermoplastic elastomer, wherein the composition (C1) has a factor JDI E < 3, wherein the factor JDI E :

[0015]

[0016] wherein T m is the melting temperature of (C1) determined via DSC, which is measured based on DIN EN ISO 11357-3:2013 with a heating rate of 20 K / min and drying the sample at 100 °C for 10 minutes under nitrogen prior to the measurement, determined at the maximum enthalpy point at the first peak in the first heating cycle,

[0017] tan delta is the energy dielectric loss factor of the components of the composition measured at 80 °C at 27 MHz according to DIN EN IEC 62631-2-2:2022.

[0018] Due to the heat distribution in the mold, the use of an electromagnetic field to fuse the expanded particles produces a different structure within the molded body compared to molded bodies obtained by applying heat in a different way, such as for example using steam, to fuse the expanded particles. In the latter case (e.g. steam molding), the heat is mainly applied to the surface of the molded body, which makes the fusion near the surface stronger compared to the interior of the molded body.

[0019] The present application also relates to a process for the preparation of a molded body comprising expanded particles comprising a composition (C1) comprising at least a thermoplastic elastomer, the process comprising the steps of

[0020] (i) loading said expanded particles comprising a composition (C1) into a mold,

[0021] (ii) fusing said expanded particles comprising a thermoplastic elastomer by at least partially supplying energy via an electromagnetic field,

[0022] wherein said composition (C1) has a factor JDI E < 3, E :

[0023]

[0024] wherein T m is the melting temperature of (C1) determined via DSC, which is measured based on DIN EN ISO 11357-3:2013 with a heating rate of 20 K / min and drying the sample at 100 °C for 10 min under nitrogen prior to the measurement, determined at the maximum enthalpy point at the first peak in the first heating cycle,

[0025] tan d is the energy dielectric loss factor of the components of the composition measured at 80 °C at 27 MHz according to DIN EN IEC 62631-2-2:2022.

[0026] The dielectric properties define the interaction of the RF field with the material. Higher losses will lead to higher temperature rise, which directly influences the molding performance. The dielectric properties are described by the real and imaginary part of the relative permittivity r = e' r - j e" r . The real part corresponds to the ability of the material to store electric field energy, while the imaginary part corresponds to the dielectric loss. The so-called loss factor tan(d) is defined as the ratio of the imaginary and real part of the permittivity (e" r / e' r ). The practical meaning becomes clear when comparing an ideal capacitor and a real capacitor. For an ideal capacitor, the current and voltage will have a phase delay of 90°. This phase delay is smaller than 90° by the loss angle d.

[0027] There are various ways to measure the dielectric properties of a material. The choice of method depends on the required frequency, sample geometry and the dielectric parameters to be expected. Guidelines for the measurement of solid dielectrics are described in DIN EN IEC 62631-2-2:2022. For the values described in the present invention, measurements are performed using an impedance analyzer (Keysight E4991B) and a dedicated sample test fixture (16453A) which allows dielectric evaluation from 1 MHz to 1 GHz in a temperature range from -55 °C to +150 °C, unless otherwise stated. The test fixture is placed in a laboratory oven to perform dielectric characterization in the temperature range expected to occur during the molding process. Prior to the measurements, the system is calibrated using open, short, load (with PTFE) compensation.

[0028] It has surprisingly been found that the use of a composition comprising a thermoplastic elastomer having a defined ratio of the melting temperature of the composition to the loss factor tan delta allows to fuse the expanded particles and to obtain a molded body having improved mechanical properties. It has been found that the temperature increase which occurs by stimulating the thermoplastic elastomer with energy at least partially via an electromagnetic field is sufficient to cause a thermal molding of the particles without melting the foam particles in the central region of the particles. According to the present invention, the specific adjustment of the melting temperature and the dielectric properties of the composition leads to improved properties of the molded body obtained when using the stimulation via an electromagnetic field.

[0029] Stimulating the thermoplastic elastomer with energy at least partially via an electromagnetic field makes a better energy distribution in the fusing step possible which in turn enables better mechanical properties of the molded body, such as a better tensile strength.

[0030] According to the present invention, the composition (C1) comprises at least one thermoplastic elastomer. The composition can comprise further components or additives. Typically, the composition (C1) comprises the thermoplastic elastomer in an amount of 50 to 100 wt.-%, based on the weight of the composition (C1), preferably in an amount of 60 to 99 wt.-%, based on the weight of the composition (C1), more preferably in an amount of 70 to 98 wt.-%, especially in an amount in the range of 85 to 97 wt.-%, more preferably in an amount in the range of 90 to 95 wt.-%, based on the weight of the composition (C1).

[0031] Useful thermoplastic elastomers include, for example, thermoplastic polyurethanes (TPU), thermoplastic polyester elastomers (such as polyether ester and polyester ester), thermoplastic co-polyamides (such as polyether co-polyamides) or thermoplastic styrene-butadiene block copolymers. Foam beads based on thermoplastic polyurethanes (TPU) are particularly preferred.

[0032] According to the present invention, the composition (C1) has a factor JDI E < 3.E :

[0033]

[0034] wherein T m is the melting temperature of (C1) determined via DSC, which is measured based on DIN EN ISO 11357-3:2013 with a heating rate of 20 K / min and drying the sample at 100 °C for 10 min under nitrogen prior to the measurement, determined at the maximum enthalpy point at the first peak in the first heating cycle,

[0035] tan delta is the energy dielectric loss factor of the components of the composition measured at 80 °C at 27 MHz according to DIN EN IEC 62631-2-2:2022.

[0036] Generally, the melting temperature of the composition (C1) is in the range of 90 °C to 170 °C, more preferably in the range of 100 °C to 160 °C, especially in the range of 110 °C to 140 °C.

[0037] The thermoplastic elastomer used for producing the foamed beads preferably has a Shore hardness in the range of 70 A to 92 A, preferably in the range of 75 A to 90 A and more preferably in the range of 80 A to 90 A, determined by DIN ISO 48-4:2021-02 (average value; indentation for 3 s), using a sample tempered at 100 °C for 20 h after preparation.

[0038] The bulk density of the foamed beads used is preferably in the range of 30 kg / m 3 to 250 kg / cm 3 .

[0039] The expanded thermoplastic polyurethane beads according to the present application belong to the group of particulate foams, which are also called expanded granules (or bead foams, particulate foams, expanded thermoplastic elastomer particles or expanded thermoplastic polyurethane beads). Particulate foams based on thermoplastic polyurethanes or other thermoplastic elastomers and molded articles made thereof (also called molded products) are known (e.g. WO 94 / 20568 A1, WO 2007 / 082838 A1, WO 2017 / 030835 A1, WO 2013 / 153190 A1, WO 2010 / 010010 A1 ) and can be used in many ways.

[0040] In the sense of the present application, foamed beads or granules, or bead foams or granule foams mean foams in the form of granules, the average length of which is preferably in the range from 1 mm to 15 mm, determined according to DS / ISO 13322-2:2021. In the case of non-spherical shapes, for example ellipsoidal granules, the average length means the longest length dimension. (Determined by 3D evaluation of the fine particles, for example by dynamic image analysis using an optical measuring device named "PartAn 3D", Microtrac).

[0041] The single-foam fine particles according to the application preferably have an average mass in the range from 0.1 mg to 50 mg, preferably in the range from 0.5 mg and 45 mg. In this context, average mass means the arithmetic mean based on a sample size of 10 different granules, wherein each granule is weighed three times.

[0042] The foamed granules according to the application generally have a bulk density in the range from 30 g / l to 250 g / l, preferably in the range from 50 g / l to 200 g / l, more preferably in the range from 70 g / l to 180 g / l. The bulk density is measured analogously to DIN ISO 60:1999, wherein the determination of the above values uses a 10 l volume container instead of a 0.1 l volume container compared to the standard, since the measurement of only 0.1 l volume is too inaccurate, in particular for low density and large mass of the foam granules.

[0043] The granule foams according to the application can optionally be optimized by additives such as dyes, processing aids, nucleating agents or stabilizers. The additives can be added during the generation of the precursor of the granule foam or during the foaming step. The precursor is the polymer composition used as input material for foaming.

[0044] Suitable additives can be present in the composition in an amount of 0.01 to 15 wt.-%, preferably in an amount of 0.1 to 10 wt.-%, in particular in an amount of 0.5 to 5 wt.-%, in each case based on the weight of the composition (C1).

[0045] In another embodiment of the present application, the granule foams can be coated.

[0046] In a preferred embodiment of the granule foam molded article according to the application, expanded thermoplastic polyurethane beads of the same composition and the same average mass are used.

[0047] In a preferred embodiment, the granule foam molded article consists of expanded thermoplastic polyurethane beads.

[0048] According to a further aspect, the present application also relates to the method as disclosed above, wherein the thermoplastic elastomer is a thermoplastic polyurethane.

[0049] In a preferred embodiment, the dielectric loss factor of the composition comprising the thermoplastic polyurethane is in the range of 0.04 to 0.2 at 27 MHz and 80 °C.

[0050] In the context of the present invention, the dielectric loss factor is determined using the composition (C1 ) of the compact material, i.e. the composition before the foaming step, or of the foamed beads after melting the foamed beads and annealing and thus obtaining the compact material, unless otherwise stated. The dielectric loss factor can be measured using a dielectric material test fixture called Keysight as described above. For this purpose, a small and compact plate has to be produced by injection molding and then cut into a sheet that can be placed in the dielectric test fixture.

[0051] According to the present invention, the expanded particles containing the thermoplastic elastomer are fused by supplying energy at least partially via an electromagnetic field. The thermal energy generated by the thermoplastic elastomer is sufficient to cause the thermal bonding of the foamed beads.

[0052] Generally, the thermal bonding of the foamed beads is achieved in a mold via high-frequency electromagnetic radiation, in particular via microwaves. High frequency is to be understood as meaning electromagnetic radiation having a frequency of no less than 100 MHz. The electromagnetic radiation used is generally in the frequency range between 100 MHz and 300 GHz. Microwaves having a frequency range of between 0.5 GHz and 100 GHz, more preferably 0.8 GHz to 10 GHz, and an irradiation time of between 1 second and 15 minutes are preferably used. The frequency range of the microwaves is preferably in line with the absorption behavior of the thermoplastic elastomer, or, conversely, the thermoplastic elastomer is selected according to the strength of its absorption behavior relative to the frequency range of the microwave device used.

[0053] The method of the present invention makes it possible to fuse the foamed beads together over a very wide frequency range.

[0054] The energy can be supplied by electromagnetic induction. For this purpose, a dielectric molding tool is placed between at least two capacitor plates generating at least one dielectric field. The expanded foamed beads are loaded into the cavities of the molding tool and heated by applying the dielectric field. As a result, the surface portions of the foamed beads melt, so that the beads become fused and form a molded part. In order to preserve the foamed morphology and melt only the surface of the beads, the method is adapted according to the materials used and the design of the molded article. Generally, the temperature within the mold is in the range of 40 °C below the melting temperature of the composition (C1 ) to 20 °C above the first melting temperature of the composition (C1 ), preferably in the range of 20 °C below the melting temperature of the composition (C1 ) to 10 °C above the first melting temperature of the composition (C1 ), in particular in the range of 10 °C below the melting temperature of the composition (C1 ) to 5 °C above the first melting temperature of the composition (C1 ). The temperature within the mold can be measured, for example, using optical sensors.

[0055] Generally, the energy input is controlled and adjusted by the applied voltage, the irradiation time and the amount of material. Before the molded part can be removed from the molding tool, it has to be stabilized and cooled. Stabilization can be achieved by stopping the active heating or by an active cooling process, such as for example described in EP 3 405 322.

[0056] The fusion by energy radiation is generally carried out in the microwave frequency range of 300 MHz to 300 GHz or in the radio frequency range of 30 kHz to 300 MHz. The microwaves are preferably applied in a frequency range between 0.5 GHz and 100 GHz, particularly preferably in a range between 0.8 GHz and 10 GHz, and the irradiation time used is between 0.1 minutes and 15 minutes. The radio waves are preferably applied in a frequency range between 500 kHz and 100 MHz, particularly preferably in a range between 1 MHz and 100 MHz, and the irradiation time used is between 0.1 minutes and 30 minutes.

[0057] According to another aspect, the present application also relates to the method as disclosed above, wherein in step (ii) the frequency of the electromagnetic field is in the range of 1 MHz to 100 MHz, especially in the range of 25 MHz to 30 MHz. Generally, the irradiation time in step (ii) is in the range of 1 second to 300 seconds.

[0058] According to the present application, the molded body generally has an average thickness in the range of 0.01 cm to 30 cm, preferably in the range of 0.1 cm to 15 cm, more preferably in the range of 0.5 cm to 10 cm, especially in the range of 1 cm to 5 cm.

[0059] Generally, the conditions in step (ii), such as the material of the mold, the distance of the plates and the frequency range used are adapted to generate an electric field of about 0.2 kV / cm to 3 kV / cm.

[0060] The properties of the composition (C1) as well as the thermoplastic elastomer used can vary in a wide range, as long as the JDI E in the range as defined above. Suitable thermoplastic elastomers can be used which for example have a molecular weight Mw in the range of 50 kg / mol to 250 kg / mol. Preferably, the molecular weight Mw is in the range of 60 kg / mol to 200 kg / mol, especially in the range of 100 kg / mol to 180 kg / mol.

[0061] The molecular weight Mw of the thermoplastic elastomer is determined in the context of the present application using GPC, unless otherwise stated. The determination of the weight average molecular weight Mw of the thermoplastic elastomer dissolved in HFIP (hexafluoroisopropanol) is achieved by GPC using the thermoplastic elastomer dissolved in HFIP (hexafluoroisopropanol), unless otherwise stated in the context of the present application. The determination of the molecular weight is achieved by two GPC columns arranged in series (PSS-gel; 100 A; 5 μ; 300*8 mm, Jordi-Gel DVB; Mixed Bed; 5 μ; 250*10 mm; column temperature 60 °C; flow rate 1 mL / min; RI detector). Calibration is performed using polymethyl methacrylate (EasyCal; from PSS, Mainz) and HFIP is used as eluent.

[0062] Expanded particles containing thermoplastic elastomers and processes for their production are known in principle from the prior art. In particular, expanded particles containing thermoplastic polyurethanes are known from the prior art.

[0063] Generally, the molecular weight can be adjusted by methods known to the person skilled in the art, for example by adjusting the process parameters during the production process, the ratio of the raw materials used or also the reactivity of the raw materials used.

[0064] Thermoplastic polyurethanes are generally produced using at least one polyisocyanate, at least one polyol and generally at least one chain extender. Components suitable for producing thermoplastic polyurethanes are known in principle to the person skilled in the art.

[0065] Suitable isocyanates within the context of the present application are in particular diisocyanates, in particular aliphatic or aromatic diisocyanates, more preferably aliphatic diisocyanates.

[0066] Furthermore, in the context of the present application, pre-reacted products can be used as isocyanate component, wherein some of the OH components have already reacted with isocyanate in the aforementioned reaction step. The product obtained is reacted with the remaining OH components in a subsequent step, i.e. the actual polymerization, thus forming the thermoplastic polyurethane.

[0067] Generally used aliphatic diisocyanates are conventional aliphatic and / or cycloaliphatic diisocyanates. Suitable aromatic diisocyanates are also known to the person skilled in the art.

[0068] Mixtures can also be used in principle. An example of a mixture is a mixture which comprises at least one further methylene diphenyl diisocyanate in addition to methylene diphenyl 4,4'-diisocyanate. The term "methylene diphenyl diisocyanate" here means diphenylmethane 2,2'-diisocyanate, diphenylmethane 2,4'-diisocyanate and / or diphenylmethane 4,4'-diisocyanate or a mixture of two or three isomers. Thus, for example, diphenylmethane 2,2'-diisocyanate or diphenylmethane 2,4'-diisocyanate or a mixture of two or three isomers can be used as further isocyanate. In this embodiment, the polyisocyanate composition can also comprise further polyisocyanates mentioned above.

[0069] If further isocyanates are used, these are present in the isocyanate composition (IC) in an amount preferably in the range from 0.1 to 20% by weight, further preferably in the range from 0.1 to 10% by weight and particularly preferably in the range from 0.5 to 5% by weight.

[0070] Preferred examples of higher functionality isocyanates are triisocyanates, such as triphenylmethane 4,4',4"-triisocyanate, and cyanurates of the diisocyanates mentioned above, and oligomers obtainable by partial reaction of diisocyanates with water, such as biurets of the diisocyanates mentioned above, and oligomers obtainable by controlled reaction of semi-blocked diisocyanates with polyols having an average of more than two, and preferably three or more hydroxyl groups.

[0071] The organic isocyanates which can be used are aliphatic, cycloaliphatic, araliphatic and / or aromatic isocyanates.

[0072] Further crosslinking agents can also be used, such as the higher functionality polyisocyanates or polyols mentioned above, or other higher functionality molecules having a plurality of isocyanate-reactive functional groups. Crosslinking of the product can also be achieved within the context of the application by using an excess of isocyanate groups in proportion to the hydroxyl groups. Examples of higher functionality isocyanates are triisocyanates, such as triphenylmethane 4,4',4"-triisocyanate and isocyanurates, and cyanurates of the diisocyanates mentioned above, and oligomers obtainable by partial reaction of diisocyanates with water, such as biurets of the diisocyanates mentioned above, and oligomers obtainable by controlled reaction of semi-blocked diisocyanates with polyols having an average of more than two, and preferably three or more hydroxyl groups.

[0073] Here, within the context of the application, the amount of crosslinking agent, i.e. the amount of higher functionality isocyanate and higher functionality polyol or higher functionality chain extender, is not more than 3% by weight, preferably less than 1% by weight, further preferably less than 0.5% by weight, based on the total mixture of components.

[0074] The polyisocyanate composition can also comprise one or more solvents. Suitable solvents are known to the person skilled in the art. Suitable examples are non- reactive solvents such as ethyl acetate, methyl ethyl ketone and hydrocarbons.

[0075] A polyol composition (PC) can be used according to the present application. According to the present application, the polyol composition (PC) can comprise at least one polyol. Suitable polyols are in principle known to the person 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. It is particularly preferred to use a polyesterol or a polyetherol as polyol. Polycarbonates can likewise be used. Copolymers can also be used in the context of the present application. Polyether polyols are particularly preferred. The number-average molecular weight of the polyols used according to the present application is preferably in the range from 500 g / mol to 5000 g / mol, for example in the range from 550 g / mol to 2000 g / mol, preferably in the range from 600 g / mol to 1500 g / mol, in particular between 650 g / mol and 1000 g / mol. According to the present application, the polyols used can be fossil-based polyols or non-fossil polyols.

[0076] According to the present application, polyetherols and also polyesterols, block copolymers and hybrid polyols such as, for example, poly(ester / amides) are suitable. According to the present application, preferred polyetherols are polyethylene glycols, polypropylene glycols. Suitable polyols can also be selected from polyadipates, polycarbonates, polycarbonate diols and polycaprolactones.

[0077] In a further embodiment, the present application thus relates to a foamed pellet as described previously, wherein the polyol composition comprises a polyol selected from the group consisting of polyetherols, polyesterols such as polycaprolactone polyols and polycarbonate polyols.

[0078] Suitable polyols are, for example, those having ether and ester blocks, for example polycaprolactones having polyethylene oxide or polypropylene oxide end blocks, or polyethers having polycaprolactone end blocks. According to the present application, preferred polyetherols are polyethylene glycols and polypropylene glycols. Suitable polyols are, for example, polytetramethylene glycol or polytrimethylene glycol. Polycaprolactones are also preferred. According to the present application, polyesterols, in particular non-fossil-based polyesterols, can also be used. Suitable polyesterols are, for example, based on succinic acid. Castor oil-based polyols or lignin-based polyols can also be used.

[0079] Mixtures of different polyols can also be used according to the present application. Preferably, the polyol / polyol composition used has an average functionality of between 1.8 and 2.3, preferably between 1.9 and 2.2, in particular 2. Preferably, the polyol used according to the present application has only primary hydroxyl groups.

[0080] In one embodiment of the present application, a polyol composition (PC) comprising at least polytetrahydrofuran is used. According to the present application, the polyol composition can comprise further polyols in addition to polytetrahydrofuran.

[0081] Suitable further polyols according to the present application are, for example, polyethers, but also polyesters, block copolymers and hybrid polyols such as, for example, poly(ester / amides). Suitable block copolymers are, for example, those having ether and ester blocks, for example polycaprolactone with polyethylene oxide or polypropylene oxide end blocks, or polyethers with polycaprolactone end blocks. Preferred polyether alcohols according to the present application are polyethylene glycol and polypropylene glycol. Polycaprolactone is also preferred as further polyol.

[0082] According to the present application, it is also possible to use non-fossil-based polytetramethylene glycol or polytrimethylene glycol, or a mixture of fossil and non-fossil-based polyols.

[0083] In a particularly preferred embodiment, the polytetrahydrofuran has a number average molecular weight Mn in the range from 500 g / mol to 5000 g / mol, preferably in the range from 500 g / mol to 2000 g / mol, further preferably in the range from 550 g / mol to 2000 g / mol, particularly preferably in the range from 650 g / mol to 1400 g / mol.

[0084] Within the context of the present application, the components of the polyol composition (PC) can vary within a wide range. The polyol composition can also comprise a mixture of various polyols.

[0085] According to the present application, the polyol composition can also comprise a solvent. Suitable solvents are known per se to the person skilled in the art.

[0086] When polytetrahydrofuran is used, the number average molecular weight Mn of the polytetrahydrofuran is preferably in the range from 500 g / mol to 2000 g / mol. The number average molecular weight Mn of the polytetrahydrofuran is further preferably in the range from 650 g / mol to 1400 g / mol.

[0087] In another embodiment, the present application also relates to a foamed pellet as described previously, wherein the polyol composition comprises a polyol selected from the group consisting of polytetrahydrofuran having a number average molecular weight Mn in the range from 500 g / mol to 5000 g / mol.

[0088] In another embodiment, the present application thus relates to the foamed pellets as described previously, wherein the polyol composition comprises a polyol selected from the group consisting of polytetrahydrofurans having a number average molecular weight Mn in the range of 500 g / mol to 2000 g / mol.

[0089] Mixtures of various polytetrahydrofurans, i.e. mixtures of polytetrahydrofurans having different molecular weights, can also be used according to the present application.

[0090] Preferred polyetherols of the present application are polyethylene glycols, polypropylene glycols and polytetrahydrofurans and mixed polyetherols thereof. Mixtures of various polytetrahydrofurans having different molecular weights can also be used according to the present application, for example.

[0091] At least one chain extender (CE1) can be used according to the present application. Suitable chain extenders are known per se to the person skilled in the art. For example, chain extenders are compounds having two groups which are reactive towards isocyanate groups, in particular those having a molecular weight of less than 500 g / mol. Suitable chain extenders are, for example, diamines or diols. Diols are more preferred according to the present application. Mixtures of two or more chain extenders can also be used within the scope of the present application.

[0092] Suitable diols are known in principle to the person skilled in the art. Diols preferably have a molecular weight of < 500 g / mol according to the present application. Aliphatic, araliphatic, aromatic and / or cycloaliphatic diols having a molecular weight of, for example, 50 g / mol to 220 g / mol are usable here as chain extenders according to the present application. Alkanediols having 2 to 10 carbon atoms in the alkylene group, in particular di-alkylene glycols, tri-alkylene glycols, tetra-alkylene glycols, penta-alkylene glycols, hexa-alkylene glycols, hepta-alkylene glycols, octa-alkylene glycols, nona-alkylene glycols and / or deca-alkylene glycols are preferred. Particularly preferred for the present application are 1,2-ethanediol, propane-1,3-diol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol.

[0093] Suitable chain extenders (CE1) within the context of the present application are also branched compounds, such as 1,4-cyclohexanedimethanol, 2-butyl-2-ethylpropanediol, neopentyl glycol, 2,2,4-trimethylpentane-1,3-diol, pinacol, 2-ethylhexane-1,3-diol or cyclohexane-1,4-diol.

[0094] In another embodiment, the present application thus relates to the foamed pellets as described previously, wherein the chain extender (CE1) is selected from the group consisting of propane-1,3-diol, ethane-1,2-diol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol and HQEE.

[0095] According to another aspect, the present application also relates to the process as disclosed above, wherein the thermoplastic polyurethane is obtained or obtainable by reacting at least components (a) to (c):

[0096] (a) a polyisocyanate composition (IC) comprising an isocyanate selected from the group consisting of methylene diphenyl diisocyanate, hexamethylene diisocyanate and pentamethylene diisocyanate;

[0097] (b) at least one chain extender (CE1),

[0098] (c) a polyol composition (PC).

[0099] The properties, in particular the molecular weight, of the obtained thermoplastic polyurethane can be adjusted, for example, by adjusting the temperature applied during the preparation. Generally, lower temperatures result in lower molecular weights. Furthermore, the use of a suitable catalyst and the amount of catalyst used can have an influence on the molecular weight of the obtained thermoplastic polyurethane. The molecular weight of the obtained thermoplastic polyurethane can also be adjusted by the ratio of the components used, in particular the ratio of NCO groups to groups that are reactive towards isocyanate groups.

[0100] Herein, the quantitative ratio of the components used is preferably chosen such that a hard segment content in the range of 5% to 80%, preferably in the range of 10% to 55%, in particular in the range of 13% to 45%, more preferably in the range of 15% to 40% is obtained. Unless stated otherwise, this hard segment content is calculated according to formula (I):

[0101]

[0102] It has been found that thermoplastic polyurethanes having a molecular weight Mwin the range of 50 kg / mol to 250 kg / mol and a hard segment content of the thermoplastic polyurethane in the range of 15% to 50% are particularly suitable for the preparation of moldings.

[0103] According to another aspect, the present application also relates to the process as disclosed above, wherein the hard segment content of the thermoplastic polyurethane is in the range of 15% to 50%, the hard segment content being calculated according to formula (I):

[0104]

[0105] Furthermore, it has been found that the crystallinity of the thermoplastic elastomer can have an influence on the properties of the mold obtained. It has been found that thermoplastic elastomers, in particular thermoplastic polyurethanes having a low crystallinity, are particularly suitable for the production of the molding body. The crystallinity can be determined by DSC measurement according to DIN EN ISO 11357-3:2018, including a 10-minute drying step at 100 °C in the measurement system before the start of the measurement, wherein the cooling rate to the starting temperature of the measurement is 20 K / min and the heating rate from the starting temperature up to 250 °C is 10 K / min.

[0106] The composition (C1) comprises a thermoplastic elastomer, but can also comprise suitable amounts of further additives, for example the composition (C1) can comprise at least one additive selected from the group of dipropylene glycol and water.

[0107] Suitable additives can also be selected from the group of esters of carboxylic acids and diols or triols, for example ethylene glycol esters of acetic acid or citric acid, glycerol esters of acetic acid or citric acid or diols and liquid polyglycols, such as triethylene glycol or tripropylene glycol, for example 1,2,3-propanetriol triacetate (triacetin, glycerol triacetate), triethylene glycol or tripropylene glycol.

[0108] In the context of the present application, metal fibers or carbon fibers can also be used as additives.

[0109] These additives can be present in the composition in an amount of 0.01 to 10% by weight, preferably in an amount of 0.01 to 5% by weight, in particular in an amount of 0.01 to 2% by weight, in each case based on the weight of the composition (C1).

[0110] In one embodiment of the present application, the granular foam comprises polar additives which increase the dielectric heating effect by absorbing electromagnetic radiation. The polar additives are preferably selected from the group consisting of inorganic salts, esters of carboxylic acids and diols or triols or glycols, amines, urea compounds, polyols and glycerol.

[0111] The polymeric foam beads can be coated with water or other polar liquids or additives containing functional groups and hydrocarbons such as urea or esters of carboxylic acids and di- or triols or glycols and liquid polyethylene glycols. Preferably, the coating is applied in a proportion of 0.1 to 10 % by weight, more preferably in a proportion of 1 to 6 % by weight, based on the granular foam used. In another embodiment of the present application, the polymeric foam beads are coated with a solution of inorganic salts, such as for example a sodium chloride solution, before fusing by electromagnetic radiation. Preferably, the concentration of the applied salt solution is in the range of 0.1 to 5 % by weight, more preferably between 0.1 and 0.8 % by weight. The above-mentioned functionalization to increase the dielectric heating intensity of non-polar polymeric foam beads can be carried out analogously to the methods described in EP 3053732 or WO16146537. In general, the polar additives are applied to polymeric foam beads that cannot be excited by electromagnetic radiation or cannot be excited sufficiently by electromagnetic radiation and thus cannot be heated without a suitable additive. For this purpose, the frequency range of the electromagnetic radiation applied is adjusted to the absorption behavior of the polar coating or additive, or vice versa, the polar liquid or additive is selected based on the absorption behavior depending on the available frequency range of the device used. The fusing polymer range of the device used. The fusing of polymeric foam beads based on thermoplastic polyurethane (TPU) or thermoplastic polyamide (TPA) by electromagnetic radiation can preferably be realized in the context of the present application without the use of polar additives.

[0112] According to the application, the composition (C1) can also comprise one or more thermoplastic polymers, in particular a suitable amount of a thermoplastic elastomer, as long as a homogeneous composition (C1) is obtained. Suitable thermoplastic polymers such as polyolefins, polystyrene or polyamides are in principle known to the person skilled in the art and can be present, for example, in an amount of 0.01 to 10 % by weight, based on the composition (C1).

[0113] The molded part can be produced by a molding machine. For this purpose, the foamed particles are either manually fed into the forming tool or automated by using pressurized air. The forming tool, also referred to as mold or molding tool, comprises two main components, an injection plate with a filling nozzle and a counter plate. In order to generate the molded part, the two plates are pressed together, thereby forming a cavity in the shape of the molded part. The filling of the mold cavity can be carried out by a crack filling method or a pressure filling method.

[0114] The crack filling method comprises the following steps:

[0115] (i') injection of the expanded foam particles into the mold cavity without back pressure of the counter plate,

[0116] (ii') fusing of the particles while mechanically closing the plates of the mold,

[0117] (iii') cooling the molded part, and

[0118] (iv') demolding the produced part,

[0119] wherein in step (i') the gap between the injection mold plate and the counter plate, also referred to as crack height, is adjusted. In step (i') the mold cavity is filled with a predetermined amount of expanded beads. In step (ii') the volume of the mold cavity is reduced compared to step (i') because the two parts of the molding tool are tightly closed, thus the intermediate gap disappears. This leads to an increase in pressure within the mold cavity. The expanded beads are thus pressed against each other and can thus fuse to obtain the molded part.

[0120] The degree of compression is an important parameter to control the quality of the fusion of the molded part. The degree of compression is calculated by dividing the dosage volume of each cycle by the volume of the mold cavity adjusted in step (ii'), wherein the dosage volume of each cycle is given by the dosage weight of each cycle divided by the bulk density of the expanded beads.

[0121] In one embodiment according to the present application, the degree of compression is in the range of 1.7 to 2.3. Preferably, the degree of compression in the crack filling method is below 2.

[0122] The pressure filling method comprises the following steps:

[0123] (i') injection of expanded foam particles into the mold cavity by pneumatic pressure while tightly pressing the two plates of the mold together,

[0124] (ii') fusing the particles,

[0125] (iii') cooling the molded part,

[0126] (iv') demolding the produced part.

[0127] Since the injection pressure applied in step (i') is stopped in step (ii'), the inserted foam beads can further expand, thus press against each other, and thus become fused and form the molded part.

[0128] The fusion in step (ii') can be induced by at least one electromagnetic field, independent of the chosen loading method.

[0129] According to another embodiment, the present application thus also relates to the method as disclosed above, wherein in step (i) the crack filling method is used.

[0130] As mentioned above, the energy is supplied by electromagnetic induction. For this purpose, a dielectric molding tool is placed between at least two capacitor plates that generate at least one dielectric field. The expanded foam beads are loaded into the cavities of the molding tool and heated by applying the dielectric field. Thus, the surface portions of the foam beads melt, so that the beads become fused and form the molded part. In order to preserve the foam morphology and melt only the bead surface, the method is adapted according to the material used and the design of the molded article. Generally, the energy input is controlled and adjusted by the applied voltage, the irradiation time and the amount of material. Before the molded part can be removed from the molding tool, it has to be stabilized and cooled. Stabilization can be achieved by stopping the active heating or by an active cooling process, such as described for example in EP 3 405 322.

[0131] The fusion by energy radiation is generally carried out in the microwave frequency range of 300 MHz to 300 GHz or in the radio frequency range of 30 kHz to 300 MHz. Microwaves are preferably applied in a frequency range between 0.5 GHz and 100 GHz, particularly preferably in a range between 0.8 GHz and 10 GHz, and the irradiation time used is between 1 second and 15 minutes. Radio waves are preferably applied in a frequency range between 500 kHz and 100 MHz, particularly preferably in a range between 1 MHz and 80 MHz, and the irradiation time used is between 1 second and 30 minutes.

[0132] The expanded particles comprising thermoplastic elastomers can be molded without the use of additional additives that can be stimulated by electromagnetic fields, in particular additives that can be stimulated by electromagnetic fields to increase the temperature in the mold. Preferably, no additives are used in the method according to the application that can be stimulated by electromagnetic fields in a way that leads to an increase in temperature in the mold.

[0133] According to a further aspect, the present application also relates to the method as disclosed above, wherein no additives are added in step (i) or (ii) that can be stimulated by electromagnetic fields leading to an increase in temperature in the mold.

[0134] According to a further aspect, the present application also relates to the use of expanded particles containing a composition (C1) comprising at least a thermoplastic elastomer for fusing the particles by at least partially supplying energy via electromagnetic fields to produce a molded body, wherein the composition (C1) has a factor JDI E <3. E :

[0135]

[0136] wherein T mis the melting temperature of (C1) determined via DSC, which is measured based on DIN EN ISO 11357-3:2013 with a heating rate of 20 K / min and drying the sample at 100 °C for 10 min under nitrogen prior to the measurement, determined at the maximum enthalpy point at the first peak in the first heating cycle,

[0137] tan delta is the energy dielectric loss factor of the composition of components measured according to DIN EN IEC 62631-2-2:2022 at 80 °C at 27 MHz.

[0138] According to another aspect, the present application also relates to a molded body obtainable or obtained by the process as disclosed above.

[0139] Due to their elastomeric properties, the bead foams of the present application can be used for applications in the field of sports, footwear and packaging, for example as safety footwear or as packaging for electronic components or instruments.

[0140] The present application additionally provides the use of the foamed pellets of the present application for the production of molded bodies for shoe midsoles, shoe insoles, shoe combination soles, bicycle saddles, bicycle tires, shock-absorbing elements, cushioning elements, mattresses, gaskets, grips, protective films, components for motor vehicle interior and exterior parts, for balls and sports equipment, or as floor coverings, in particular for sports grounds, track and field grounds, sports halls, children's playgrounds and roads. The present application additionally provides the use of the foamed pellets of the present application for the production of consumer or industrial goods, parts in the field of motor vehicles or packaging.

[0141] It is preferred that the foamed pellets of the present application are used for the production of molded bodies for shoe midsoles, shoe insoles, shoe combination soles or cushioning elements for shoes.

[0142] Here, the shoe is preferably an outdoor shoe, a sports shoe, a sandal, a boot or a safety shoe, particularly preferably a sports shoe.

[0143] According to another aspect, the present application also relates to the use of a molded body according to or obtainable according to the process as disclosed above in shoe soles, shoe sole parts, shoe midsoles, shoe insoles, shock-absorbing elements, cushioning elements, gaskets, grips, floors, mattresses, sports goods, bicycle saddles, tires and in motor vehicle interior and exterior parts. According to another aspect, the present application also relates to the use of a molded body as disclosed above in shoe soles, shoe sole parts, shoe midsoles, shoe insoles, shock-absorbing elements, cushioning elements, gaskets, grips, floors, mattresses, sports goods, bicycle saddles, tires and in motor vehicle interior and exterior parts.

[0144] Further embodiments of the present application can be found in the claims and embodiments. It should be understood that the features of the subject-matter / method / use according to the present application described above and set forth in the claims below can be combined with each other in any way, not only in the combinations explicitly indicated in each case. For example, the combination of preferred features with particularly preferred features or of features not further characterized with particularly preferred features etc. is thus also implicitly covered, even if this combination is not explicitly mentioned.

[0145] Exemplary embodiments of the present application are listed below, but these do not limit the present application. In particular, the present application also encompasses those embodiments resulting from the combination of the properties cited and thus specified hereinafter.

[0146] 1. Molded body comprising expanded particles fused using electromagnetic fields, the expanded particles containing a composition (C1), the composition comprising a thermoplastic elastomer, wherein the composition (C1) has a factor JDI E < 3. E

[0147]

[0148] wherein T m is the melting temperature of (C1) determined via DSC, which is measured based on DIN EN ISO 11357-3:2013 with a heating rate of 20 K / min and drying the sample at 100 °C for 10 min under nitrogen prior to the start of the measurement, determined at the maximum enthalpy point at the first peak in the first heating cycle,

[0149] tan delta is the energy dielectric loss factor of the component of the composition measured at 80 °C at 27 MHz according to DIN EN IEC 62631-2-2:2022.

[0150] 2. Molded body according to embodiment 1, wherein the thermoplastic elastomer is a thermoplastic polyurethane.

[0151] 3. Molded body according to embodiment 1 or 2, wherein the molded body has an average thickness in the range of 0.1 cm to 30 cm.

[0152] 4. Molded body according to any one of embodiments 1 to 3, wherein the molded body has a tensile strength of more than 0.6 MPa, preferably more than 0.7 MPa, more preferably more than 0.8 MPa, more preferably more than 0.85 MPa, more preferably more than 0.9 MPa, especially more than 1.0 MPa, determined according to ASTM D 5035:2015.

[0153] ​5. Process for the preparation of a molded body comprising expanded particles containing a composition (C1), the composition comprising at least a thermoplastic elastomer, the process comprising the steps of

[0154] (i) loading the expanded particles containing a composition (C1) into a mold,

[0155] (ii) fusing the expanded particles containing a thermoplastic elastomer by at least partially supplying energy via an electromagnetic field,

[0156] wherein the composition (C1) has a factor JDI E < 3, E :

[0157] wherein T m is the melting temperature of (C1) determined via DSC, the melting temperature being measured based on DIN EN ISO 11357-3:2013 with a heating rate of 20 K / min and drying the sample at 100 °C for 10 min under nitrogen prior to the measurement, determined at the maximum enthalpy point at the first peak in the first heating cycle,

[0158] tan delta is the energy dielectric loss factor of the component of the composition measured at 80 °C at 27 MHz according to DIN EN IEC 62631-2-2:2022.

[0159] 6. The process according to embodiment 5, wherein the thermoplastic elastomer is a thermoplastic polyurethane.

[0160] 7. The process according to embodiment 5 or 6, wherein the molded body has an average thickness in the range of 0.1 cm to 30 cm.

[0161] 8. The process according to any one of embodiments 5 to 7, wherein the thermoplastic elastomer is a thermoplastic polyurethane having a Shore hardness in the range of 70 A to 92 A.

[0162] 9. The process according to any one of embodiments 5 to 8, wherein the composition (C1) comprises at least one further thermoplastic polymer, in particular at least one further thermoplastic elastomer.

[0163] 10. The process according to any one of embodiments 5 to 9, wherein the composition (C1) comprises at least one additive selected from the group consisting of dipropylene glycol and water.

[0164] 11. The method according to any one of embodiments 5 to 10, wherein in step (ii) a voltage of 3 kV to 9 kV is applied for a duration of 1 s to 300 s.

[0165] 12. The method according to any one of embodiments 5 to 11, wherein in step (i) a crack-filling method is used.

[0166] 13. The method according to any one of embodiments 5 to 12, wherein no additives are added in step (i) or (ii) which are capable of being stimulated by an electromagnetic field leading to an increase in temperature in the mold.

[0167] 14. Use of expanded particles containing a composition (C1) comprising at least a thermoplastic elastomer for producing a molded body by at least partially fusing the particles via an electromagnetic field supply of energy, wherein the composition (C1) has a factor JDI E < 3 in the range of 0.3 < JDI E

[0168]

[0169] wherein T m is the melting temperature of (C1) determined via DSC, which is measured based on DIN EN ISO 11357-3:2013 with a heating rate of 20 K / min and drying the sample at 100 °C for 10 min under nitrogen prior to the measurement, determined at the maximum enthalpy point at the first peak in the first heating cycle,

[0170] tan delta is the energy dielectric loss factor of the component of the composition measured at 80 °C at 27 MHz according to DIN EN IEC 62631-2-2:2022.

[0171] 15. The use according to embodiment 14, wherein the thermoplastic elastomer is a thermoplastic polyurethane.

[0172] 16. The use according to any one of embodiments 14 or 15, wherein the thermoplastic elastomer is a thermoplastic polyurethane having a Shore hardness in the range of 70 A to 92 A.

[0173] 17. The use according to any one of embodiments 14 to 16, wherein the composition (C1) comprises at least one further thermoplastic polymer, in particular at least one further thermoplastic elastomer.

[0174] 18. The use according to any one of embodiments 14 to 17, wherein the composition (C1) comprises at least one additive selected from the group consisting of dipropylene glycol and water. ​

[0175] 19. Molding, obtainable by or by the method according to any one of embodiments 5 to 13.

[0176] 20. Molding, obtainable by or by a method for producing a molding, the molding comprising expanded particles comprising a composition (C1) comprising at least a thermoplastic elastomer, the method comprising the steps of

[0177] (i) loading the expanded particles comprising a composition (C1) into a mold,

[0178] (ii) fusing the expanded particles comprising a thermoplastic elastomer by at least partially supplying energy via an electromagnetic field,

[0179] wherein the composition (C1) has a factor JDI E < 3 in the range of 0.3 < JDI E :

[0180]

[0181] wherein T m is the melting temperature of (C1) determined via DSC, which is measured based on DIN EN ISO 11357-3:2013 with a heating rate of 20 K / min and drying the sample at 100 °C for 10 min under nitrogen prior to the measurement, determined at the maximum enthalpy point at the first peak in the first heating cycle,

[0182] tan delta is the energy dielectric loss factor of the component of the composition measured at 80 °C at 27 MHz according to DIN EN IEC 62631-2-2:2022.

[0183] 21. The molding according to embodiment 20, wherein the thermoplastic elastomer is a thermoplastic polyurethane.

[0184] 22. The molding according to embodiment 20 or 21, wherein the molding has an average thickness in the range of 0.1 cm to 30 cm.

[0185] 23. The molding according to any one of embodiments 20 to 22, wherein the thermoplastic elastomer is a thermoplastic polyurethane having a Shore hardness in the range of 70 A to 92 A.

[0186] 24. The molding according to any one of embodiments 20 to 23, wherein the composition (C1) comprises at least one further thermoplastic polymer, in particular at least one further thermoplastic elastomer.

[0187] 25. The molding according to any one of embodiments 20 to 24, wherein the composition (C1) comprises at least one additive selected from the group consisting of dipropylene glycol and water.

[0188] 26. The molding according to any one of embodiments 20 to 25, wherein in step (ii) a voltage of 3 kV to 9 kV is applied for a duration of 1 s to 300 s.

[0189] 27. The molding according to any one of embodiments 20 to 26, wherein in step (i) a crack-filling method is used.

[0190] 28. The molding according to any one of embodiments 20 to 27, wherein no additive is added in step (i) or (ii) which is capable of being stimulated by an electromagnetic field leading to an increase in temperature in the mold.

[0191] 29. Use of the molding according to any one of embodiments 1 to 4 or of the molding obtained according to or capable of being obtained according to the method according to any one of embodiments 5 to 13 in shoe soles, shoe sole parts, midsoles, insoles, shock-absorbing elements, cushioning elements, pads, grips, floorings, mattresses, sports goods, bicycle saddles, tires and in interior and exterior parts of motor vehicles.

[0192] 30. Molding comprising expanded particles fused using an electromagnetic field, the expanded particles containing a composition (C1) comprising a thermoplastic polyurethane, wherein the composition (C1) has a factor JDI E < 0.3 < JDI E < 3.

[0193]

[0194] wherein T m is the melting temperature of (C1) determined via DSC, which is measured based on DIN EN ISO 11357-3:2013 with a heating rate of 20 K / min and drying the sample at 100 °C for 10 min under nitrogen prior to the measurement, determined at the maximum enthalpy point at the first peak in the first heating cycle,

[0195] tan d is the energy dielectric loss factor of the component of the composition measured at 80 °C at 27 MHz according to DIN EN IEC 62631-2-2:2022.

[0196] wherein the particle foam molding consists of expanded thermoplastic polyurethane beads.

[0197] 31. Process for the preparation of a molded body comprising expanded particles containing a composition (C1), the composition comprising at least a thermoplastic elastomer, the process comprising the steps of

[0198] (i) loading the expanded particles containing a composition (C1) into a mold,

[0199] (ii) fusing the expanded particles containing a thermoplastic elastomer by at least partially supplying energy via an electromagnetic field,

[0200] wherein the composition (C1) has a factor JDI E < 3 in the range of 0.3 < JDI E :

[0201]

[0202] wherein T m is the melting temperature of (C1) determined via DSC, the melting temperature being measured based on DIN EN ISO 11357-3:2013 with a heating rate of 20 K / min and drying the sample at 100 °C for 10 min under nitrogen prior to the measurement, determined at the maximum enthalpy point at the first peak in the first heating cycle,

[0203] tan d is the energy dielectric loss factor of the component of the composition measured at 80 °C at 27 MHz according to DIN EN IEC 62631-2-2:2022,

[0204] wherein the fusing with electromagnetic radiation is achieved without using a polar additive.

[0205] 32. Process for the preparation of a molded body comprising expanded particles containing a composition (C1), the composition comprising at least a thermoplastic elastomer, the process comprising the steps of

[0206] (i) loading the expanded particles containing a composition (C1) into a mold,

[0207] (ii) fusing the expanded particles containing a thermoplastic elastomer by at least partially supplying energy via an electromagnetic field,

[0208] wherein the composition (C1) has a factor JDI E < 3 in the range of 0.3 < JDI E :

[0209]

[0210] wherein T mis the melting temperature of (C1) determined via DSC, which is measured based on DIN EN ISO 11357-3:2013 with a heating rate of 20 K / min and drying the sample at 100 °C for 10 min under nitrogen prior to the measurement, determined at the maximum enthalpy at the first peak in the first heating cycle,

[0211] tan delta is the energy dielectric loss factor of the composition of components measured according to DIN EN IEC 62631-2-2:2022 at 80 °C at 27 MHz,

[0212] wherein no additive is added in step (i) or (ii) which is capable of being stimulated by an electromagnetic field to cause an increase in temperature in the mold.

[0213] 33. The method according to any one of embodiments 31 to 32, wherein the thermoplastic elastomer is a thermoplastic polyurethane.

[0214] 34. The method according to any one of embodiments 31 to 33, wherein the composition (C1) comprises at least one additive selected from the group consisting of dipropylene glycol and water.

[0215] 35. The method according to any one of embodiments 31 to 34, wherein in step (ii) a voltage of 3 kV to 9 kV is applied for a duration of 1 s to 300 s.

[0216] 36. The method according to any one of embodiments 31 to 35, wherein in step (i) a crack-filling method is used.

[0217] 37. A molded body, which is obtainable by or by the method according to any one of embodiments 31 to 36.

[0218] 38. Use of a molded body obtained or obtainable according to the method according to any one of embodiments 31 to 36 in shoe soles, shoe sole parts, midsoles, insoles, shock-absorbing elements, cushioning elements, pads, grips, floorings, beddings, sports goods, bicycle saddles, tires, and in automotive interior and exterior parts.

[0219] The application is further described by examples. The examples relate to practical and in some cases preferred embodiments of the application, which do not limit the scope of the application. Example

[0220] 1 Preparation of the sample and reference material

[0221] 1.1 Synthesis of the TPU by extrusion

[0222] The following examples (see table 1 for components) were prepared:

[0223] The production of the examples and references was carried out in a twin-screw extruder ZSK58 MC from Coperion with a process length of 48 D (12 barrels). Discharge of the melt from the extruder took place via a gear pump. After melt filtration, the polymer melt was processed into granules by underwater pelletizing, which was dried continuously in a heated vortex bed at 40 to 90 °C.

[0224] The polyols, chain extenders and diisocyanates and, if necessary, catalysts were metered into the first zone. The supply of further additives took place in zone 8, as described above.

[0225] The barrel temperatures were in the range from 150 to 230 °C. The melt discharge and underwater pelletizing took place at a melt temperature of 210 to 245 °C. The screw rotation speed was between 180 and 240 1 / min. The throughput was in the range from 180 to 220 kg / h.

[0226] Table 1 : Composition of the thermoplastic materials metered in the reaction extruder as example and reference (counterexample) materials Amount of the fractions

[0227]

[0228] * 1,4-butanediol

[0229] ** 1,6-hexanediol

[0230] These preparations of the examples and references resulted in thermoplastic polyurethanes having the properties listed in table 2.

[0231] Table 2

[0232]

[0233] 1.2 ETPU obtained by extrusion

[0234] After production of the raw materials, they were further processed into expanded

[0235] The thermoplastic polyurethane granules were as follows.

[0236] For this purpose, the dried sample and reference material (see Table 1) were mixed and melted together with additional additives (0.05% to 0.15% by weight of talc as a nucleating agent and possible chain extender (0.6% to 1.2% by weight of polymer composition x-Flex 2905MB, BASF Polyurethanes GmbH) in a twin-screw extruder (ZE40, KraussMaffei Berstorff) at a temperature range of 160°C to 220°C.

[0237] As a blowing agent, CO2 (1.1% to 2.2% by weight based on the polymer composition) and N2 (0.1% to 0.25% by weight based on the polymer composition) are injected into the melt in an extruder and mixed with thermoplastic polyurethane and other additives to form a homogeneous melt.

[0238] The exact polymer compositions of the various embodiments and counterexamples are listed in Table 1. The molten mixture was then pumped via a gear pump (approximately 160°C to 200°C, depending on the material composition) into a perforated plate (approximately 180°C to 200°C, depending on the material composition), cut into granules in the cutting chamber of an underwater granulation (UWG) machine, and transported and expanded underwater with conditioned and pressurized water.

[0239] After separating the expanded particles from the water using a centrifugal dryer, the expanded particles were dried at 60°C for 2 hours.

[0240] 1.3 ETPU obtained by the vessel / batch process

[0241] Reference material 3 was prepared by container / batch method (Table 2).

[0242] Thermoplastic polyurethane beads are impregnated with butane and nitrogen in a can or autoclave at a temperature of 100°C to 120°C and a pressure of 20 bar to 38 bar, wherein the foaming agent is 20% to 30% by weight.

[0243] The sudden drop in pressure caused the foaming agent to expand and the reference material 3 to foam.

[0244] Centrifugal dryer is used to separate the beads from the water, and finally warm air is used for drying and degassing.

[0245] 2. Moulding of the eTPU

[0246] The bead foams were molded using Wave Foamer C from Kurtz company at an electromagnetic field frequency of 27.14 MHz (radio frequency molding) and a capacitor plate distance of 4.5 cm. The mold was prepared from polyethylene terephthalate with a length and width of 200 mm each and a variable height which could be set to 10 mm and 20 mm.

[0247] For molding, the cavity was opened and the required amount of material (previously accurately weighed) was placed evenly into one half of the open mold by hand. Then, the mold was closed to a height of 10 mm and the molding process was started. The foam beads were irradiated for a certain time at a certain voltage, followed by a cooling step. Finally, the mold was opened again and the part was demolded.

[0248] The amount (weight) of bead foam used and the molding conditions used are shown in Table 3. The plates were produced by adjusting the core of the mold to a final volume of 200 x 200 x 10 mm 3 The manufacturing procedure was carried out as described above. The stabilization of the plates was completed by waiting time (passive cooling) according to the table below.

[0249] Table 3

[0250]

[0251] The examples and comparative examples in Table 3 show that the molded bodies according to the application have a higher tensile strength than the comparative examples.

[0252] 3. Methods used

[0253] 3.1 DSC

[0254] DSC was measured based on DIN EN ISO 11357-3:2013 with a heating rate of 20 K / min (drying of the test specimen at 100 °C for 10 min under nitrogen prior to the start of the measurement). The melting temperature was determined at the maximum enthalpy point at the first peak in the first heating cycle.

[0255] 3.2 Tensile strength E-TPU

[0256] The measurement was carried out according to ASTM D 5035:2015 using test specimens (150 x 25 mm, 4 x 10 mm; punched from the plates) at a test rate of 100 mm / min.

[0257] 3.3 Part density

[0258] The density of the foamed parts made from thermoplastic polymers was determined based on DIN EN ISO 845:2009.

[0259] 3.4 Dielectric properties

[0260] For the values described in the present application, measurements were made using an impedance analyzer (Keysight E4991B) and a dedicated sample test fixture (16453A) that allows dielectric evaluation from 1 MHz to 1 GHz in the temperature range from -55°C to +150°C according to DIN EN IEC 62631-2-2:2022. The test fixture was placed in a laboratory oven for dielectric characterization in the temperature range expected to occur during the molding process. Prior to the measurements, the system was calibrated using open circuit, short circuit, load (with PTFE) compensation.

[0261] Cited literature

[0262] WO2014 / 198779 A1

[0263] WO2015 / 052265 A1

[0264] DE102013110242 A1

[0265] EP3698949 A1

[0266] WO2017 / 125410 A1

[0267] WO2017 / 125410 A1

[0268] EP3808522 A1

[0269] WO 2017 / 125410 A1

[0270] WO 2001 / 64414A1

[0271] WO 2019 / 162172 A1

[0272] DE 10 2013 012 515 A1

[0273] WO 94 / 20568A1

[0274] WO 2007 / 082838 A1

[0275] WO2017 / 030835A1

[0276] WO 2013 / 153190 A1

[0277] WO 2010 / 010010 A1

[0278] EP3405322A1

[0279] Kunststoffhandbuch [Plastics Handbook], Volume 7, "Polyurethane [Polyure- thanes]", Carl Hanser Verlag, 3rdedition 1993, Chapter 3.1

Claims

1. A molded body comprising expanded particles fused using an electromagnetic field, said expanded particles containing a composition (C1) comprising a thermoplastic elastomer, wherein said composition (C1) has a JDI content of 0.3 < JDI. E Factor JDI in the range of <3 E : Where T m The melting temperature (C1) was determined by DSC based on DIN EN ISO 11357-3:2013, with a heating rate of 20 K / min and the sample dried at 100 °C under nitrogen for 10 minutes before the start of the measurement. It was determined at the maximum enthalpy point at the first peak during the first heating cycle. tanδ is the energy dielectric loss factor of the components of the composition, measured at 80°C and 27MHz according to DIN EN IEC 62631-2-2:2022.

2. The molded body according to claim 1, wherein the thermoplastic elastomer is thermoplastic polyurethane.

3. The molded article according to claim 1 or 2, wherein the particulate foam molded article is composed of expanded thermoplastic polyurethane beads.

4. A method for preparing a molded body comprising expanded particles containing a composition (C1), said composition comprising at least a thermoplastic elastomer, said method comprising the following steps: (i) Loading the expanded particles containing the composition (C1) into a mold, (ii) The expanded particles containing the thermoplastic elastomer are fused together by supplying energy, at least partially via an electromagnetic field. The composition (C1) wherein has a concentration of 0.3 < JDI E Factor JDI in the range of <3 E : Where T m The melting temperature (C1) was determined by DSC based on DIN EN ISO 11357-3:2013, with a heating rate of 20 K / min and the sample dried at 100 °C under nitrogen for 10 minutes prior to the start of the measurement. The melting temperature was determined at the maximum enthalpy point at the first peak during the first heating cycle. tanδ is the energy dielectric loss factor of the components of the composition, measured at 80°C and 27MHz according to DIN EN IEC 62631-2-2:2022.

5. The method of claim 4, wherein fusion by electromagnetic radiation is achieved without the use of polar additives.

6. The method according to any one of claims 4 or 5, wherein no additives that can be stimulated by an electromagnetic field and cause the temperature in the mold to rise are added in step (i) or (ii).

7. The method according to any one of claims 4 to 6, wherein the thermoplastic elastomer is thermoplastic polyurethane.

8. The method according to any one of claims 4 to 7, wherein the composition (C1) comprises at least one additive selected from the group consisting of dipropylene glycol and water.

9. The method according to any one of claims 4 to 8, wherein in step (ii), a voltage of 3 kV to 9 kV is applied for a duration of 1 second to 300 seconds.

10. The method according to any one of claims 4 to 9, wherein in step (i), a crack filling method is used.

11. Use of expanded particles containing at least a thermoplastic elastomer (C1) for fusing said particles by supplying energy at least partially via an electromagnetic field to prepare a molded body, wherein said composition (C1) has a density of 0.3 < JDI E Factor JDI in the range of <3 E : Where T m The melting temperature (C1) was determined by DSC based on DIN EN ISO 11357-3:2013, with a heating rate of 20 K / min and the sample dried at 100 °C under nitrogen for 10 minutes prior to the start of the measurement. The melting temperature was determined at the maximum enthalpy point at the first peak during the first heating cycle. tanδ is the energy dielectric loss factor of the components of the composition, measured at 80°C and 27MHz according to DIN EN IEC 62631-2-2:2022.

12. A molded body that can be obtained by or by any one of claims 4 to 10.

13. Use of the molded body according to any one of claims 1 to 3, or the molded body obtained by or according to any one of claims 4 to 10, in shoe soles, shoe sole parts, shoe midsoles, shoe insoles, shock-absorbing elements, cushioning elements, padding, grips, flooring, mattresses, sporting goods, bicycle saddles, tires, and in motor vehicle interior and exterior parts.

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