3d-printable compositions comprising polylactic acid and a crosslinked functional ethylene-vinyl acetate copolymer

Abstract

A 3D-printable composition in the form of a filament, a granule or a plurality thereof comprising a polymer composition that comprises polylactic acid and a crosslinked ethylene-vinylacetate copolymer having at least one functional groups that is crosslinked. Also provided is a spool comprising wound up onto it the 3D-printable composition in the form of a filament, a process of producing an article by 3D-printing, 3D-printed articles and a process for making the 3D-printable composition.

Description

[0001] 3D-PRINTABLE COMPOSITIONS COMPRISING POLYLACTIC ACID AND A CROSSLINKED FUNCTIONAL ETHYLENE-VINYL ACETATE COPOLYMER

[0002] Background

[0003] Additive manufacturing, also commonly referred to as 3D-printing , has been adopted widely by businesses and individuals to replace or supplement more traditional forms of manufacture. Various 3D-printing techniques and printers are available. Almost of all of them involve melting and solidifying a material to form an article. Many 3D-printers use filaments or granules as feedstock. 3D-printers using filaments as feedstock are known in the art as FFF-printers (fused filament fabrication) and printers using granules as feedstock are referred to on the art as FGF-printers (fused granular fabrication). In such machines, a filament or granules are heated and extruded through a nozzle which deposits the material on a removable platform (printer bed) to build up the desired object layer-by-layer. FFF- based and FGF-based printers are commercially available and so are filaments or granules for 3D-printing. Common materials for producing such filaments and granules are based on polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS) as described, for example, in international patent application WO2015148521A1. Thermoplastic materials are easy to process by 3D-printing while elastomeric materials are not because elastomeric materials do not melt. Another problem with 3D-printing of elastomers is poor layer-to-layer adhesion such that multi-layer articles are difficult to produce. 3D-printing of elastomeric materials is desirable because they impart higher elasticity on the articles compared to thermoplastic materials. In international patent application WO2015197515A1 3D-printing of thermoplastic polyurethanes is reported to produce 3D-printed articles that have some elasticity. In KR1020160029309A filaments are disclosed prepared from blending a biodegradable polymer, which can be a polylactic acid, and a polyolefin bearing a hydrophilic group. In JP2021130250A filaments made from blends of a biodegradable polymer, which can be a polylactic acid, and an ethene-vinylacetate copolymer. According to this document, preferably a mixture of ethene-vinylacetate copolymers is used and the ethene-vinylacetate copolymers may be cross-linked before they are blended with the biodegradable polymer.

[0004] While the 3D-printing technology has undergone notable improvements in recent years, further improvements remain desirable.

[0005] Summary

[0006] Therefore, in one aspect there is provided a 3D-printable composition in the form of a filament, a granule or a plurality thereof comprising a polymer composition that comprises at least one thermoplastic polymer comprising a polylactic acid and at least one cross-linked functionalized elastomer having at least one functional group that is cross-linked and wherein the elastomer is an ethylene-vinylacetate polymer comprising units derived from ethylene and vinylacetate.

[0007] In another aspect there is provided a spool comprising, wound up onto it, the 3D-printable composition in the form of a filament.

[0008] In a further aspect there is provided a process of producing an article comprising providing the 3D-printable composition, or a plurality thereof, and subjecting it to 3D-printi ng in at least one 3D-printer suitable for printing filaments or granules to create at least one shaped article.

[0009] In yet another aspect there is provided an article comprising at least a component obtained by the process.

[0010] In yet a further aspect there is provided a process for making the 3D-printable composition comprising a step (i) comprising providing a polymer composition comprising of mixture of (a) at least one thermoplastic polymer comprising a polylactic acid, and (b) at least one elastomer, wherein the elastomer is an ethylene-vinylacetate polymer comprising units derived from ethylene and vinylacetate and is functionalised to comprise at least one functional group that can be cross-linked in a curing reaction and, optionally, (c) at least one curing agent for cross-linking the functional group; a step (ii) comprising forming the polymer composition into a filament, a granule or a plurality thereof, a step (iii) comprising subjecting the polymer composition to curing, optionally, in the presence of a curing agent, wherein step (iii) is carried out before, during or after step (ii).

[0011] Brief Description of the Drawings

[0012] Figure 1 is a schematic representation of a 3D-printer.

[0013] Figure 2 is a schematic view of a coiled filament.

[0014] Figure 3 is a schematic view of pellets which can be used as feedstock.

[0015] Corresponding reference characters indicate corresponding parts throughout the several views. Detailed Description

[0016] In the following description the terms "comprising”, "containing”, "including", "having" are not intended to exclude the presence of any additional component, step or procedure. For example, a composition referred to herein as “comprising components A and B” means other components may be present in that composition, in addition to the components A and B.

[0017] In the following description norms may be used. If not indicated otherwise, the norms are used in the version that was in force on March 1 , 2020. If no version was in force at that date because, for example, the norm has expired, the version is referred to that was in force at a date that is closest to March 1 , 2020.

[0018] In the following description the amounts of ingredients of a composition or polymer may be indicated interchangeably by “weight percent”, “wt. %” or “% by weight”. The terms “weight percent”, “wt. %” or “% by weight” are based on the total weight of the composition or polymer, respectively, which is 100 % unless indicated otherwise.

[0019] The term “phr” means parts per hundred parts of rubber.

[0020] Ranges identified in this disclosure include and disclose all values between the endpoints of the range and include the end points unless stated otherwise.

[0021] The term “substituted” is used to describe hydrocarbon-containing organic compounds where at least one hydrogen atom has been replaced by a chemical entity other than a hydrogen. That chemical entity is referred to herein interchangeably as “substituent”, “residue” or “radical”. For example, the term “a methyl group substituted by fluorine” refers to a fluorinated methyl group and includes the groups -CF3, -CHF2and -CH2F. The term “unsubstituted” is meant to describe a hydrocarbon-containing organic compound of which none of its hydrogen atoms have been replaced. For example, the term “unsubstituted methyl residue” refers to a methyl, i.e. -CH3.

[0022] For a complete understanding of the present invention and the advantages thereof, reference is made to the following detailed description.

[0023] It should be appreciated that the various aspects and embodiments of the detailed description disclosed herein are illustrative of the specific ways to make and use the invention and do not limit the scope of invention when taken into consideration with the claims and the detailed description. It will also be appreciated that features from different aspects and embodiments of the invention may be combined with features from different aspects and embodiments of the invention.

[0024] 3D-printinq and 3D-printable compositions

[0025] The 3D-printable compositions according to the present disclosure can be used in a process to produce articles by 3D-printing in at least one 3D printer. Typically, the 3D-printable compositions are provided in the form of elongated or spherical articles. In a preferred embodiment of the present disclosure the 3D-printable compositions are in the form of granules (also referred to as “pellets”) or filaments. A filament typically is an elongated article and may have a diameter of from 1 to 12 mm, preferably from 1 mm to 5 mm or from 1 mm to 3 mm. In one embodiment of the present disclosure the filament has a length of at least 50 mm, preferably at least 3 m. Typical filaments for use in commercial FFF-printers have a diameter of 1 .75 mm or 2.85 mm.

[0026] Typically, a granule has a diameter of from 1 mm up to 100, preferably up to 13 mm and a length of less than 50, preferably less than 23 mm.

[0027] The granules may be of spherical, oval or, typically, of cylindrical shape. Mixtures of granules with different shapes may be used. The granules may have a diameter of from about 1 mm to about 100 mm, preferably up to about 13 mm. They may have a length from about 1 mm and less than 50 mm, preferably less than 23 mm.

[0028] The filaments and granules preferably have a constant diameter, but in case the granule or filament do not have a constant diameter but different diameters, the largest diameter is referred to for the dimensions described above. The dimensions for the length refer to the length orthogonal to the diameter.

[0029] The use of filaments and granules in 3D printers is well known in the art. When granules or filaments are used as feedstock, 3D printers with a suitable printer head for printing such materials are used. Typically, the printer head comprises a heated extruder. 3D-printing with granules is referred to in the art also as “FGF” (fused granular fabrication) and 3D-printing with filaments is referred to in the art also as “FFF” (fused filament fabrication). FGF- and FFF- based 3D printers are commercially available and may be used. A typical 3D-printing process involves heating the filament or granule, extruding the molten filament or granule through a nozzle, which typically forms the printer head or is a part thereof, and depositing it onto a removable platform (printer bed). The printer head or the printer bed (platform) can be moved with respect to each other such that an object can be formed by depositing the 3D- printable material onto the platform, where it solidifies, layer by layer to create a three- dimensional object.

[0030] T o improve the adhesion between the platform (bed) and the first layer of deposited (printed) material, the bed may be heated, or an adhesive may be used or a combination thereof. The 3D-printable compositions according to the present disclosure have a good layer-to- layer adhesion so that multiple layers can be printed onto each other. After the printing has been completed the 3D-printed article may be removed from the platform.

[0031] A typical 3D-printing process is described, for example in WO2015 / 148521 A, incorporated herein by reference. FIG. 1 schematically depicts the use of an additive manufacturing apparatus 1 to form an object 4 using a filament 2 according to the present disclosure. The additive manufacturing apparatus 1 shown in FIG. 1 can be a conventional 3D-printing apparatus as known in the art or as commercially available. Such apparatus typically includes a positioning system 5 which controls the position and movement of extruder and heating element 6. Positioning system 5 controls the position at which the heated filament 2 is deposited to form part of the object in a three-dimensional space and is oftentimes referred to as an x-y-z positioning system.

[0032] The object 4 being made is supported on a build platform 7 that, in some apparatus, includes a thermal control system. A 3D model of the object to be built is communicated to controller 8 which is used to control the operation of the apparatus 1 . Although controller 8 is depicted as a single component, it may take the form of multiple processing units that are in communication with 1 . A spool 3 with filament 2 feeds heated extruder 6 with material for forming object 4.

[0033] The feed-rate of filament 2 and temperature of the extrusion heating element 6 are controlled by controller 8 which are factors that can affect the physical properties and color of the material in final product 4. Although a single built object 4 is illustrated, an almost limitless number of different types of objects can be made using an additive manufacturing process. Although a relatively simple apparatus 1 is depicted, the filament 2 may be used in a more complex apparatus. For example, multiple filaments 2 may be used in an apparatus having multiple extrusion nozzles with each nozzle being fed by a different filament spool this allows the printer to quickly switch between filaments having different properties, such as different colors or different physical properties. 3D printers adapted to process filaments are known in the art as “FFF-printers”. Such printers are commercially available. Oftentimes, filaments for 3D printers are wrapped on spools, as depicted in Fig. 2, with the 3D printers being adapted to have the spools removably mounted thereon to allow for the convenient loading of filaments on the 3D printer and easy feeding of the filament to the nozzle of the printer. The use of such spools is well known in the art. Therefore, in one aspect of the present disclosure there is provided a spool comprising the 3D-printable composition according to the present disclosure in the shape of a filament wound up onto the spool.

[0034] Filaments can be formed by extruding the polymer composition according to the present disclosure through a die as is known in the art, typically by melting the polymer compositions and extruding them through a die. Typically, the extruded filaments are cooled for example by feeding them through a water bath. To make filaments of great length, e.g., “continuous filaments” the first end of the extrudate may be attached to a spool that is connected to a motor that controls the rotation speed of the spool and thus also controls the line feet and drawing force onto the extrudate.

[0035] Instead of forming a filament 2, the 3D-printable composition according to the present disclosure could, instead, be used to form pellets 9 as schematically depicted in FIG. 3. When using granules as feedstock the 3D-printing process is essentially the same as has been illustrated in Fig. 1 except that granules are used as feedstock. Granules are not fed to the nozzle by a spool but rather by a hopper or other appropriate feeding devices. 3D printers adapted to process granules are known in the art as “FGF-printers”. Such printers are commercially available.

[0036] Granules can be prepared in the same way as filaments but for making granules the extrudate is cut into granule length sections. These granules could then be used in a subsequent extrusion process to form a filament or as feedstock for a 3D printer. When using the granules to form a filament, it may be advantageous to add one or more additive to the composition before extruding the filament. Likewise, one or more additives may be added to the polymer composition according to the present disclosure before or during forming the composition into granules or filaments.

[0037] In a preferred embodiment of the present disclosure, the 3D-printable composition has a tensile strength of at least 5 MPa, preferably at least 10 MPa, as determined according to DIN 53505, and a peak maximum melting temperature, Tm, obtained from the second heating run at 10 K / min according to DIN 53765 using differential scanning calorimetry (DSC) of from 110°C to 280°C, preferably from 120°C to 250°C. Preferably, the 3D-printable composition has an elongation at break of at least 15%, preferably at least 40%. Preferably, the 3D-printable compositions have either an elongation at break of at least 50% or at least 100% as determined according to DIN 53504, or a melt flow index (MFI) at 210°C and 21.2 kg load of at least 1 g / 10 min as determined according to DIN EN ISO 1 133. In one embodiment of the present disclosure the 3D-printable composition is elastic as determined by having an elongation at break of at least 90%, at least 100% or at least 200%. In one embodiment of the present disclosure the 3D-printable composition has a tensile strength of at least 14 MPa.

[0038] In one embodiment of the present disclosure the 3D-printable composition has a tensile strength of at least 7 MPa, preferably at least 12 MPa, as determined according to DIN 53504 and a peak maximum melting temperature, Tm, obtained from the second heating run at 10 K / min according to DIN 53765 using differential scanning calorimetry (DSC), from 1 10°C to 280° C, preferably from 130 to 280°C. The composition either has an elongation at break of at least 50%, or at least 90%, or at least 100%, as determined according to DIN 53504, or a melt flow index (MFI) at 210°C and 21.2 N load of at least 1 g / 10 min as determined according to DIN EN ISO 1133 or both.

[0039] Polymer compositions

[0040] The 3D-printable compositions according to the present disclosure can be obtained by shaping a polymer composition into articles, preferably into filaments or granules as described above. Therefore, the 3D-printable compositions according to the present disclosure comprises a polymer composition. The polymer composition comprises a blend comprising at least one thermoplastic polymer and at least one elastomer. The elastomer may be a functionalized elastomer comprising one or more functional groups that can be cross-linked in a curing reaction and thus cross-link the elastomer. The curing reaction can be carried out by subjecting the functional group to curing, which can be done by physically, for example but not limiting to UV-curing, curing by irradiation with y-beams or laser beams. Typically, the curing reaction is carried out chemically, for example, in the presence of at least one curing agent or curing system capable of cross-linking the functional groups.

[0041] Preferably, the elastomer is a functionalized elastomer and comprises one or more functional groups that can be cross-linked for cross-linking the elastomer in a curing reaction. Preferably, the polymer composition is at least partially cured and comprises the functionalized elastomer in at least partially cured form, preferably where at least a fraction of the functional groups of the functionalized elastomer has been subjected to a curing reaction to cross-link the elastomer. The polymer composition may comprise the reaction product of curing the blend comprising the at least one thermoplastic polymer and the at least one elastomer, preferably at least one functionalized elastomer. Preferably, the curing is carried out in the presence of at least one curing agent or curing system capable of cross- linking the one or more functional group of the functionalized elastomer. Preferably, the polymer composition is a thermoplastic vulcanizate (TPV), which is a compound that contains cross-linked elastomer particles dispersed in a thermoplastic matrix. Typically, thermoplastic polymers (also referred to herein as “thermoplasts”) have melting points and are thermally processable, which means they can be shaped, molten and reshaped. Thermoplasts are not elastic, i.e. they have no or only a low elongation at break. Vulcanisates are cross-linked elastomers. They are elastic but cannot be thermally processed by shaping, melting and reshaping because the cross-linked elastomers do not have a melting point and do not melt. TPVs are cross-linked compositions comprising a thermoplast and an elastomer, wherein at least the elastomer is cross-linked. The crosslinked elastomer is dispersed as small particles in the thermoplast matrix. TPV’s can be obtained by mixing the elastomer and thermoplast, typically at a temperature above the melting point of the thermoplast. Typically, the elastomer is dispersed into the molten thermoplast. The mixture is subjected to dynamic curing. Typically, curing of elastomers is carried out in a mold, typically under application of heat, pressure or both. This curing method does not apply shear forces and is referred to herein as “static curing”. In dynamic curing the curing is carried out under application of shear forces, preferably in addition to the application of heat. During curing the elastomer particles begin to cross-link. Under the conditions of dynamic curing the cross-linking elastomer particles are prevented from forming a continuous phase by the shear forces applied and are dispersed again as particles in the thermoplast phase. Upon cooling, the thermoplast solidifies with the crosslinked elastomer particles dispersed in it, and thus “freezes” the phase distribution generated in the dynamic curing. The resulting compound, the TPV, has a predominantly continuous thermoplastic phase in which the cross-linked elastomers form a discontinuous phase, or thermoplast and cross-linked elastomer form a co-continuous phase. TPV’s have a melting point because of the presence of the continuous thermoplast phase but also have some elasticity due to the presence of the dispersed cross-linked elastomer particles. Therefore, thermoplastic vulcanizates show thermoplastic behavior, for example they have a melting point and can be reshaped by melting and cooling but also have elastic properties due to the presence of the cross-linked elastomer particles.

[0042] Preferably, the ethylene vinyl acetate (EVM) elastomer is cured or at least partially cured in the curing reaction. Preferably, a functionalized elastomer is used, which either ensures that only the elastomer is cured or facilitates the cross-linking of the elastomer, or both. The curing reaction then only or predominantly affects the functional groups of the functionalized elastomer through which the elastomer cross-links. A further advantage of using a functionalized elastomer instead of a non-functionalized elastomer is that greater amounts of elastomer can be used for making the blend, and the resulting cross-linked blend still has a melting point and can be processed by melting. Greater amounts of elastomeric component may lead to softer and more elastic articles. Greater amounts include amounts of elastomer that are equal to or greater (by weight) than the amount of thermoplastic polymer.

[0043] A non-functionalized elastomer may also be blended with a thermoplastic polymer to provide a blend that has a melting point and that can be thermally processed into filaments or granules. However, in this case the elastomeric component may only be present in an amount that is equal or less than the amount (weight) of thermoplastic polymer. Moreover, the resulting compounds may be less elastic. In a preferred embodiment of the present disclosure, the polymer composition has a tensile strength of at least 5 MPa, preferably at least 10 MPa, as determined according to DIN 53505, and a peak maximum melting temperature, Tm, obtained from the second heating run at 10 K / min according to DIN 53765 using differential scanning calorimetry (DSC), of 110°C to 280° C. Preferably, the polymer composition has an elongation at break of at least 15%, preferably at least 40%, more preferably at least 90%. Preferably, the polymer compositions have either an elongation at break of at least 50%, or at least 90%, or at least 100% as determined according to DIN 53504, or a melt flow index (MFI) at 210°C and 21.2 N load of at least 1 g / 10 min as determined according to DIN EN ISO 1133. In one embodiment of the present disclosure the polymer composition has an elongation at break of at least 100% or at least 200%. In one embodiment of the present disclosure the polymer composition has a tensile strength of at least 14 MPa. The ingredients and their amounts may be selected to reach these properties. Optimum amounts can be determined by routine experimentation.

[0044] Preferably, for making the polymer composition the thermoplastic polymer and elastomer may be blended in a weight ratio of thermoplastic polymer to elastomer of from 1 : 10 to 10: 1 or from 1 :5 to 5:1. In one embodiment, the polymer composition has a weight ratio of thermoplastic polymer to elastomer from 3: 1 to 1 :3. In one embodiment of the present disclosure the elastomer, preferably the elastomer, is present in a greater amount by weight than the thermoplastic polymer, and, preferably, is present in amount of at least 50% by weight based on the total weight of the composition. The polymer composition according to the present disclosure may comprise, for example, from 5% by weight to 95% by weight of thermoplastic polymer and from 95% by weight to 5% by weight of elastomer (based on the total weight of the polymer composition). Preferably, the polymer composition comprises from 15% by weight to 85 % by weight of thermoplastic polymer and from 85% by weight to 15% by weight of elastomer (based on the total weight of the polymer composition), or from 51 % by weight and up to 75% by weight, or up to 85% by weight or up to 95% by weight of elastomer (based on the total weight of the polymer composition). In another preferred embodiment of the present disclosure the polymer composition comprises from 25% by weight to 75 % by weight of thermoplastic polymer and from 75% by weight to 25% by weight of elastomer (based on the total weight of the polymer composition). It is understood that the elastomer and thermoplastic polymer may be present as reaction product of a curing reaction, i.e., at least the elastomer may be present in cross-linked or partially cross-linked form.

[0045] In one embodiment of the present disclosure the polymer composition comprises at least 50% by weight, preferably at least 90% by weight, more preferably at least 95% by weight and most preferably at least 98% by weight, based on the weight of the polymer composition, of the reaction product of curing a blend comprising the at least one thermoplastic polymer and the at least one elastomer of the present disclosure, preferably the at least one functionalized elastomer according to the present disclosure.

[0046] Preferably, the 3D-printable compositions according to the present disclosure may be obtained by a process comprising: a step (i) comprising combining the elastomer and the thermoplastic polymer and, optionally, one or more additive to prepare the polymer composition; a step (ii) comprising forming the polymer composition into a filament, a granule or a plurality thereof, a step (iii) comprising subjecting the polymer composition to curing wherein the step (iii) is carried out before, during or after step (ii).

[0047] The polymer composition provided in step (i) is preferably obtained by dispersing the elastomer in the thermoplastic polymer at conditions where the thermoplastic polymer is in a molten form.

[0048] Step (ii) preferably comprises shaping by extrusion. In this step (ii), the polymer composition may be shaped into granules. The granules may be molten and reshaped, for example into filaments, or vice versa. Both filaments and granules can be reshaped by melting and cooling them. Additives may be added prior to the formation of the filaments or granules or afterwards, for example before or during (an optional) reshaping of the granules or filaments. Additives including those described below, may also be added during step (i) or during step (ii) or during both steps. Additives (in particular curing agents) may also be blended with the elastomer before blending the elastomer with the thermoplastic polymer. Additives may also be blended with the thermoplastic polymer before blending it with the elastomer. Additives may also be added to the blend of elastomer and thermoplastic polymer.

[0049] The curing in step (iii) is preferably carried out in the presence of a curing agent but may also be carried out by physical curing, in which case a functional group is chosen that crosslinks upon physical curing.

[0050] The elastomer according to the present disclosure preferably is an EVM polymer. Preferably, although not necessary, the EVM polymer is functionalized to comprise at least one functional group that can cross-link in a curing reaction. If a functionalized EVM polymer is used, preferably at least one curing agent is added during or after making the polymer composition and the process may comprise the step (iii) comprising subjecting the polymer composition to curing. The curing agent is selected from those that are capable of crosslinking the respective functional groups. The type and amount of curing agent depends on the functional group and as is known to the skilled person. Non-limiting examples of functional groups and curing agents will be described below. The curing step (iii) may be carried out before, during or after step (ii). Preferably, the curing is carried out by dynamic curing, i.e., by curing during application of shear force, for example curing in an extruder. Preferably, the curing is carried out during step (ii), for example during extrusion, for example when extruding the polymer composition into filaments or granules. The curing (vulcanization) of the functionalized elastomer typically may be carried out at a temperature in the range of 100 to 250°C, preferably 140 to 220°C, particularly preferably 160 to 200°C. Preferably, the curing is carried out as dynamic curing, i.e., curing is carried out under shear force, for example during extrusion, for example in an extruder, preferably also at elevated temperature, preferably at conditions where the thermoplast is molten.

[0051] The 3D-printable compositions according to the present disclosure may comprise from 10% and up to at least 50%, up to at least 75%, up to at least 90% or even up to 100% by weight, based on the total weight of the 3D-printable composition, of a polymer composition according to the present disclosure.

[0052] EVM Polymers

[0053] The elastomers used in the present disclosure preferably are EVM polymers. EVM polymers as referred to herein are copolymers comprising units derived from ethylene and vinyl acetate and are also referred to herein as “ethylene-vinylacetate polymers”. The EVM polymers may have a content of units derived from vinyl acetate of at least 40% and up to 90% by weight, based on the total weight of the polymer. Preferably, they comprise at least 45% by weight or at least 50% by weight of units derived from vinyl acetate, for example between 50% and 75% by weight. Preferably, the amount of units derived from vinyl acetate is less than 90% by weight. Copolymers consisting of ethylene and vinyl acetate having a content of vinyl acetate below 40% and above 90% by weight typically are thermoplastic materials. Preferably, the EVM polymers have a content of units derived from ethylene at least 10% by weight based on the total weight of the polymer, preferably at least 15%, or at least 20%, or at least 25% by weight.

[0054] The EVM polymers, may have a Mooney viscosity (ML (1+4) 100°C) of at least 10 Mooney units (MU), preferably between 10 and 75 Mooney units. The EVM polymers may typically have a melt flow index (MFI, 190°, 2.16 kg) of 1 g to 75 g / 10 min, for example from 1g to 15 g / 10 min or from 5g to 35 g / 10 mins, or from 16 g to 75 g / 10 min. The EVM polymers may typically have a polydispersity (PDI) from 2 to 10, preferably from 3 to 8. PDI is determined as PDI = Mw / Mn, where Mwrepresents the weight average and Mnthe number average of the molecular weight. The EVM polymers may typically have a weight average molar mass Mw from 30 000 g / mol to 400 000 g / mol, preferably from 60 000 g / mol to 375000 g / mol or from 100 000 g / mol to 340 000 g / mol. The EVM polymers may typically have a glass transition temperature from -45 to +25 °C, preferably from -40 to +20 °C or from -35 to +15 °C (measured by DSC with a heating rate of 10 K / min).

[0055] In a preferred embodiment according to the present description the EVM polymer is a functionalized polymer. Preferably, the EVM polymer is functionalized to comprise at least one functional group that can be cross-linked in a curing reaction. The one or more functional group may be activated thermally, or by irradiation or chemically by using one or more curative agent. Examples of suitable functional groups include carbon-carbon double bonds, carbon-carbon triple bonds, epoxy groups, anhydride groups, hydroxy groups, carboxylate groups and combinations thereof. Preferably, the functionalized EVM polymer has a minimum content of units derived from the one or more functionalized comonomers of 0.1% by weight, preferably 0.5% by weight or 0.8% by weight, based on the total weight of the copolymer. Preferably, the functional group can be cross-linked chemically, i.e., by means of a curing agent or curing system.

[0056] In one embodiment of the present disclosure the functional group is an anhydride group.

[0057] Anhydride groups include those according to the general formula (1): In formula (1) R1 represents a chemical bond or a Ci-C6alkyl, a Ci-C6halogenated alkyl, a Ci-C6hydroxy alkyl, a Ci-C6alkyl ether or a polyether with 3 to 12 C-atoms. R2 represents a -CH2- group of which one hydrogen atom, optionally, may be substituted with a halogen, a Ci-C6alkyl, a Ci-C6halogenated alkyl, a Ci-C6hydroxy alkyl, a Ci-C6alkyl ether or polyether. R3 is a -CH2- group of which one hydrogen atom, optionally, may be substituted with a halogen, a C2-C6alkylene or alkylalkylene, a Ci-C6halogenated alkylene or alkylalkylene, a Ci-C6hydroxy alkylene or alkylalkylene, a C3-C6alkylene ether or alkyetheralkylene or alkyletheretheralkylene. The * indicates the connection to the polymer chain.

[0058] In another embodiment of the present disclosure the functional group is an epoxide group as represented in formula (2):

[0059] In formula (2) m is either 0 or 1 ;

[0060] X is O, O(CR2)P, (CR2)PO, C(=O)O, C(=O)O(CR2)P, C(=O)NR, (CR2)P, N(R), N(R)(CR2)P, P(R), P(R)(CR2)P, P(=O)(R), P(=O)(R)(CR2)P, S, S(CR2)P, S(=O), S(=O)(CR2)P, S(=O)2(CR2)Por S(=O)2, wherein R is H or a linear or branched hydrocarbon group having from 1 bis 13 carbon atoms that may comprise one or more O-atom, in addition carbon and hydrogen atoms ;

[0061] Y represents a divalent unit derived from a mono- or polyunsaturated monomer having from 2 to 20 carbon atoms selected from conjugated or non-conjugated dienes, alkynes and vinyl compounds, or Y represents a divalent unit having from 2 to 10 carbon atoms and one or more heteroatoms in addition to hydrogen atoms, wherein the heteroatoms are selected from O, Si and N and combinations thereof, preferably Y is selected from polyalkylene glycol ethers, polyalkylene oxides, polysiloxanes, polyols, polycarbonates, polyurethanes, polyisocyanates, polysaccharides, polyesters and polyamides, n and p are the same or different and are each in the range of 0 to 10 000, preferably 0 to 100 and especially preferably n is in the range from 0 to 100 and at the same time P = 0, R4, R5and R6are identical or different and represent H or a C1-C3 alkyl, preferably at least two and more preferably all of R4, R5and R6represent H.

[0062] In a preferred embodiment of the present disclosure the functional group corresponds to formula (2) wherein R4, R5, R6are all H, n is 0, m is 1 , X corresponds to = OR’, R”OR’, C(=O)OR’ and preferably X is C(=O)OR’. R’ is a linear or branched diavalent alkylene having from 1 to 20 carbon atoms and that, optinally, may be unsaturated, and wherein in case the alyklene has more than 1 carbon atom the alkylene chain, optionally, may be interrupted once or more than once by an oxygen atom. More preferably, R’ is (-CH2)q- with q being 1 , 2, 3, or from 4 to 12. R” is a cycloalkyl, an aryl or an alkyaryl and preferably is benzyl or an alkylated benzyl.

[0063] The functional groups may be introduced as known in the art, for example by grafting or by using functionalized comonomers. Preferably, the functional group is introduced by using one or more functionalized comonomers. Therefore, in one embodiment according to the present disclosure, the EVM polymer further comprises units derived from one or more functionalized comonomer, i.e., a comonomer bearing at least one functional group. Preferably, the functionalized comonomer is an alpha-olefinic monomer bearing one or more functional groups that can be cross-linked.

[0064] Preferably, the maximum content of the one or more functionalized comonomers is 10% by weight, or 6.2% by weight, 5.0% by weight, or 4.5% by weight. The % by weight are based on the total weight of the copolymer.

[0065] In one embodiment of the present disclosure the functional comonomer is an anhydride- functionalized monomer and bears one or more anhydride group. Anhydride groups include those according to the general formula (3):

[0066] Formula (3) is identical with formula (1) except that the * indicates the connection to an olefinic monomer having from 1 to 12 carbon atoms. Preferably the olefinic monomer is an alpha-olefin selected from ethylene, propylene, butene, acrylate or methacrylate.

[0067] In one embodiment of the present disclosure the functionalized comonomer comprises at least one epoxy group. Suitable epoxy-functionalized comonomers include those of general formula (4): wherein X, m, Y, n, R4, R5and R6are described as in formula (2) above. R1, R2, and R3, represent, independently from each other, a linear or branched alkyl, aryl, heteroaryl, arylalkyl, heteroarylalkyl, alkoxy, aryloxy, heteroaryloxy, amino, amido, carbamoyl, alkylthio, arylthio, sulphanyl, thiocarboxyl, sulphinyl, sulphono, sulphino, sulpheno, sulphonic acids, sulphamoyl, hydroxyimino, alkoxycarbonyl, hydroxyl, phosphonato, phosphinato, silyl, silyloxy, nitrile, borates, selenates, carbonyl, carboxyl, oxycarbonyl, oxysulphonyl, oxo, thioxo, epoxy, cyanates, thiocyanates, isocyanates, thioisocyanates or isocyanides. Preferably, R1and R2both represent H and R3represents H or CH3.

[0068] In a preferred embodiment of the present disclosure the functional group corresponds to formula (2) wherein R1, R2, R4, R5, R6are all H, R3is H or CH3, n is 0, m is 1 , X corresponds to = OR’, R”OR’, C(=O)OR’ and preferably X is C(=O)OR’, R’ is a linear or branched diavalent alkylene having from 1 to 20 carbon atoms and that, optinally, may be unsaturated, and wherein in case the alyklene has more than 1 carbon atom the alkylene chain, optionally, may be interrupted once or more than once by an oxygen atom, R” is a cycloalkyl, an aryl or an alkyaryl and preferably is benzyl or an alkylated benzyl. More preferably, R’ is (-CH2)q- with q being 1 , 2, 3, or from 4 to 12.

[0069] Preferred examples of epoxy-functionalized comonomers include but are not limited to glycidyl(meth)acrylates. Preferred examples include 2-ethylglycidyl acrylate, 2-ethylglycidyl methacrylate, 2-(n-propyl)glycidyl acrylate, 2-(n-propyl)glycidyl methacrylate, 2-(n- butyl)glycidyl acrylate, 2-(n-butyl)glycidyl methacrylate, glycidylmethyl acrylate, glycidylmethyl methacrylate, glycidyl acrylate, (3',4'-epoxyheptyl)-2-ethyl acrylate, (3', 4'- epoxyheptyl)-2-ethyl methacrylate, 6',7'-epoxyheptyl acrylate, 6',7'-epoxyheptyl methacrylate, allyl glycidyl ether, allyl 3,4-epoxyheptyl ether, 6,7-epoxyheptyl allyl ether, vinyl glycidyl ether, vinyl 3,4-epoxyheptyl ether, 3,4-epoxyheptyl vinyl ether, 6,7- epoxyheptyl vinyl ether, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p- vinylbenzyl glycidyl ether and 3-vinylcyclohexene oxide.

[0070] Preferably, the copolymer comprises units derived from a functional comonomer selected from a glycidyl (alkyl)acrylate, preferably selected from glycidyl acrylate, glycidyl methacrylate or a combination thereof. Preferably the copolymer comprises only one type of epoxy-functionalized comonomer. Although the functional groups have been described with embodiments where the functional groups are either comprise an anhydride group or an epoxy group it will be understood by the person skilled in the art that other functional groups with their corresponding curing agents / systems may be used as well.

[0071] Further, optional comonomers

[0072] The EVM polymers according to the present disclosure may also comprise units derived from further, optional comonomers, for example from 0 to 20% by weight based on the total weight of the EVM polymer. The further, optional monomers can each be used individually or in combination. The total amount of these further optional comonomers may be 15% by weight or less, and preferably 10% by weight or less, or 5% by weight or less. The total content of units derived from ethylene, vinyl acetate, functionalized comonomers and optional further comonomers adds up to 100% by weight, based on the total weight of the copolymer.

[0073] The further, optional comonomers may be non-functionalized or functionalized but not with functional groups that can be cross-linked.

[0074] Specific Examples of such further, optional comonomers include, but are not limited to, alkyl acrylates and methacrylates having from 1 to 8 carbon atoms in the alkyl portion. Further examples include alkoxyalkyl (meth)acrylates having from 2 to 8 carbon atoms in the alkoxy alkyl portion. Further examples include polyethylene glycol (meth)acrylates, preferably with 1 to 12 ethylene glycol units. Other examples include vinyl esters, preferably vinyl propionate and vinyl butyrate, vinyl ketones, preferably methyl vinyl ketone and ethyl vinyl ketone, vinyl aromatic compounds, preferably styrene, a-methylstyrene and vinyltoluene; conjugated dienes, preferably butadiene and isoprene; a-monoolefins, preferably propylene and 1 -butene; vinyl monomers having a hydroxyl group, preferably p-hydroxyethyl acrylate and 4-hydroxybutyl acrylate; vinyl and vinylidene monomers having a nitrile group, preferably acrylonitrile, methacrylonitrile and 3-cyanoethyl acrylate; unsaturated amide monomers, preferably acrylamide and N-methylmethacrylamide. Yet further examples include (meth)acrylic acid esters including those described in US2018 / 0112020 A1.

[0075] Preferably, the EVM polymer according to the present disclosure comprises no units derived from one or more further, optional comonomers or comprises less than 1% by weight of such units. In a preferred embodiment, the EVM polymer comprises only units derived only from monomers selected from ethylene, vinyl acetate and one or more, preferably one, epoxy-functionalized comonomer. Preferably, the epoxy-functionalized comonomer carries at least one glycidyl group.

[0076] The units derived from the monomers may be distributed statistically over the polymer chain of the EVM polymer or may be distributed as blocks. A random distribution is preferred.

[0077] The EVM polymers may be prepared by solution polymerization, as known in the art, or as described, for example, in US2017 / 0335037 A1. They are also commercially available, for example, under the trade designation LEVAPREN, LE AMELT and LEVAPREN NPG from ARLANXEO Deutschland GmbH, Germany.

[0078] The major or even exclusive components of the EVM polymers, i.e., the ethylene and vinyl acetate monomers, typically are obtained from fossil resources, for example by distillation from fossil raw materials in so-called naphtha-crackers. However, as described, for example, in international patent application WO2019 / 202405 A1 , both monomers can be obtained from sustainable resources also, for example, from renewable sources such as plants including sugar canes. To obtain ethylene from a renewable source (also referred to as “bio-based ethylene”), the renewable source is first fermented to produce ethanol. The ethanol is then subjected to a dehydration reaction to form ethylene. For making bio-based vinyl acetate the renewable source is fermented to produce ethanol, which is then oxidized to form acetic acid. The acetic acid is then reacted with ethylene (which may also be a biobased ethylene) to produce vinyl acetate.

[0079] Both monomers may also be obtained from recycled materials, for example recycled plantbased materials or recycled plastic or rubber, for example, obtained by pyrolysis. Both, the use of monomers obtained from recycled materials or from renewable sources will reduce the carbon dioxide footprint of the polymer production (see, for example WO2019 / 202405 A1) or Pete Spanos et al., ‘Sustainable Keltan EPDM’ in rubberworld.com, pages 46-52, April 2023, where the principle has been demonstrated forthe generation and use of ISCC+- certified ethylene in EPDM polymers. The principles shown there for ethylene-propylene- diene polymers (EPDM) can be applied also to the use of ethylene and vinyl acetate for making EVA-copolymers). Therefore, in one embodiment, there is provided a 3D-printable composition that comprises from at least 50% by weight, or even at least 75% by weight or even at least 95% by weight, based on the total weight of the composition of ingredients obtained from one or more sustainable resource, preferably form a plant-based resource. The plant-based origin can be determined by the C14 content as described, for example, in W02019 / 202405A1 , incorporated herein by reference. Thermoplastic Polymers

[0080] It is believed that the thermoplastic polymer used in the polymer compositions according to the present disclosure is not critical and can be selected depending on the desired endproperties of the article, or for economic reasons or both. Preferably, the thermoplastic polymer is selected from the group consisting of polypropylene homo- and copolymers, polylactic acid homo- and copolymers, and polyethylene terephthalate homo- and copolymers. It is understood that the homo- or copolymers include unmodified and modified polymers, i.e., homo- or copolymers that may be modified or functionalized. The thermoplastic polymer may be random polymer, a block-polymer, a core-shell polymer, a coupled polymer, a grafted (co)polymer or a blend of one or more polymers. Preferably, the thermoplastic polymer has a melting point of from 110 to 280 °C. Preferably, the thermoplastic polymer has an MFI measured at 210 °C with 21.2 N load of from 1 to 100 g / 10 min, preferably from 2 to 57 g / 10 min, or from 2 to 15g / min. Preferably, the thermoplastic polymer is a poly lactic acid homo- or copolymer. Polylactic acids may comprise units derived from L- or D-lactic acid or both.

[0081] Additional Ingredients (Additives)

[0082] The 3D-printable compositions and the polymer compositions according to the present disclosure may comprise one or more additional ingredients, also referred herein as “additives”. Additives may be used as known in the art. Typical additives include but are not limited to curing agents, fillers, stabilizers like antioxidants or light stabilizers, processing aids, dyes and pigments, rheology modifiers, viscosity modifiers. They may be used as needed, if needed at all and in amounts as appropriate as can be identified or optimized by routine experiments. Typical total amounts of additives include, for example, from 0 to 100 parts by weight or from 1 to 10 parts by weight per 100 parts of weight of the 3D-printable composition. Specific examples of some additives will be described in greater detail below.

[0083] Cross-linker (Curing agents):

[0084] In one embodiment of the present disclosure the 3D-printable composition is at least partially cured, for example by having subjected the functionalized EVM polymer to at least partial curing in the presence of a suitable cross-linker (curing agent). A cross-linker as known in the art may be used that is capable of cross-linking the functionalized EVM- polymer. The cross-linker may be a single cross-linker or a combination of two or more cross-linker or may comprise a crosslinking system comprising one or more cross-linker and one or more cross-linking aids. Typical examples of cross-linkers include a low molecular weight crosslinker but also cross-linkers of a higher weight may be used. Low molecular weight crosslinkers include those having a molar mass of up to 2000 g / mol, preferably up to 1000 g / mol, for example cross-linkers having a molecular weight of up to 600 g / mol, up to 400 g / mol or up to 200 g / mol. The low molecular weight crosslinkers may be aliphatic, aromatic, heteroaromatic, cycloaliphatic or heterocycloaliphatic compounds. Preferred examples for cross-linking functional groups containing an epoxy-group include polycarboxylic acids, polycarboxylic esters, polycarboxylic anhydrides or combinations thereof. They may be di-, tri- or tetracarboxylic acids. Specific examples include aliphatic dicarboxylic acids, preferably glutaric acid, dodecanedioic acid, adipic acid or combinations thereof. Further specific examples of aliphatic low molecular weight crosslinkers are: malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, dodecanedioic acid, tridecanetrioic acid, tetradecanedioic acid, octadecanedioic acid, eicosandioic acid, methylmalonic acid, ethylmalonic acid, tetramethylsuccinic acid, 2;2'- dimethylsuccinic acid, malic acid, a-methylmalic acid, a- hydroxy glutaric acid, a- hydroxyadipic acid, oxosuccinic acid, 2-oxoadipic acid, acetylmalonic acid, 2- hydroxy glutaric acid, maleic acid, citraconic acid, glutaconic acid, muconic acid, citric acid, tartaric acid, 1 ,2,3-propanetricarboxylic acid, 1 ,2,3-propenetricarboxylic acid, 1 ,3,5- pentanetricarboxylic acid, cystine, aspartic acid, glutamic acid, 2-hydroglutamic acid, iminodiacetic acid, ethylenediaminetetraacetic acid, maleic anhydride, methylmaleic anhydride, succinic anhydride, dodecenyl succinic anhydride, ethylenediaminetetraacetic dianhydride, polyacelaic polyanhydride, glutaric anhydride, 2,2'dimethylglutaric anhydride, sebacic anhydride, azelaic anhydride, dodecanedioic anhydride, eicosandioic anhydride, citraconic anhydride, cyclomaleic anhydride, diglycolic anhydride, and thioglycolic anhydride.

[0085] Examples of aromatic low molecular weight crosslinkers include phthalic acid, 3- methylphthalic acid, terephthalic acid, phthalonic acid, hemipinic acid, benzophenone dicarboxylic acid, phenylsuccinic acid, trimellitic acid, pyromellitic acid, phthalic anyhdride, diphenic anhydride, isatoic anhydride, trimellitic anhydride, pyromellitic anhydride, tetrahydrophthalic anhydride, tetrachlorophthalic anhydride, and tetrabromophthalic anhydride.

[0086] Examples of cycloaliphatic low molecular weight crosslinkers include: hexahydrophthalic acid, hexahydroterephthalic acid, cis-1 ,3-cyclopentanedicarboxylic acid, cis-1 ,4- cyclohexanedicarboxylic acid, 1 ,5-cyclooctanedicarboxylic acid, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, and 1 ,2-cyclohexanedicarboxylic anhydride. The low molecular weight crosslinkers may be used individually or in combination. They may be used in a total amount of usually 0.1 to 15 parts by weight, preferably 0.5 to 5 parts by weight, per 100 parts by weight of the EVM polymer. Preferably, the amounts are selected so that about one carboxyl group of the low molecular weight crosslinker is added per epoxy group of the EVM polymer.

[0087] The cross-linker may be used in combination with one or more crosslinking aids as known in the art. Examples include quaternary ammonium salt or phosphonium salt of the formula where Y is a nitrogen or phosphorus atom, each of the radicals Ri, R2, R3 and R4is independently selected from an alkyl, aryl, alkylaryl or polyoxyalkylene group having from 1 to 25 carbon atoms, wherein two or three of these groups may form a heterocyclic ring system together with the nitrogen atom or the phosphorus atom Y. Preferably, R1, R2, R3 and R4are independently selected from an alkyl group having from 1 to 10 carbon atoms or an aryl or alkylaryl group having from 6 to 10 carbon atoms. X- represents an anion of an inorganic or organic acid. Preferred anions include Cl’, Br, k, HSO4_, H2PO4_, R5COO’, R5OSO3’, RsSO’ and R5OPO3’ where R5is an C1-C10-alkyl group of an aryl or alkylaryl group having from 6 to 10 carbon atoms.

[0088] Specific examples include tetraethylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium iodide, n-dodecyltrimethylammonium bromide, cetyldimethylbenzylammonium chloride, methylcetyldibenzylammonium bromide, cetyldimethylethylammonium bromide, cetyltrimethylammonium bromide, octadecyltrimethylammonium bromide, cetylpyridium chloride, cetylpyridium bromide, 1 ,8- diazabicyclo[5.4.0]undecene-7-methylammonium methosulphate, 1 ,8- diazabicyclo[5.4.0]undecene-7-benzylammonium chloride, cetyltrimethylammonium alkylphenoxypoly(ethyleneoxy)ethyl phosphate, cetylpyridium sulphate, tetraethylammonium acetate, trimethylbenzylammonium benzoate, trimethylbenzylammonium p-toluenesulphonate and trimethylbenzylammonium borate.

[0089] Specific examples of quaternary phosphonium salts include triphenylbenzylphosphonium chloride, triphenylbenzylphosphonium bromide, triphenylbenzylphosphonium iodide, triphenylmethoxymethylphosphonium chloride, triethylbenzylphosphonium chloride, tricyclohexylbenzylphosphonium chloride, trioctylmethylphosphonium dimethyl phosphate, tetrabutylphosphonium bromide and trioctylmethylphosphonium acetate.

[0090] The quaternary ammonium and phosphonium salts may be used in a total amount of usually 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, per 100 parts by weight of the EVM polymer. The optimum amounts can be identified by routine experiments.

[0091] Fillers:

[0092] Typical fillers include carbon black, aluminium hydroxide, aluminum oxide, microspheres, magnesium hydroxide, talc, silica, calcium carbonate, aluminium silicate, titanium oxide, and zinc oxide. Silanes, for example, can be added to modify the filler surface during manufacture of the 3D-printable composition. Fillers that have been surface-modified in a previous process may be used.

[0093] Antioxidants:

[0094] Antioxidants may be used as known in the art. Typically, they are used in amounts of 0 to 5 parts by weight or 0.5 to 3 parts by weight, based on 100 parts by weight of the 3D- printable composition.

[0095] Processing aids:

[0096] Processing aids include, for example, saturated or partly unsaturated fatty acids and oleic acids and derivatives thereof (fatty acid esters, fatty acid salts, fatty alcohols, fatty acid amides). These agents are used in amounts of 0 to 10 parts by weight, preferably 0 to 2 parts by weight, particularly preferably 0 to 1 part by weight, based on 100 parts by weight of the 3D-printable composition.

[0097] Articles / Applications

[0098] The 3D-printable compositions according to the present disclosure may be used for making articles by 3D-printing. The articles may be soft and elastic because of the presence of the EVM polymer. The 3D-printable compositions may be 3D-printed to produce elastic articles, for example articles having an elongation at break of at least 90%. Typical articles (or components of articles) that may be produced with the 3D-printable compositions include, but are not limited to, fixtures, hoses, tubing, connectors, seals including O-rings, bottle caps, and noise-damping articles. The present disclosure is illustrated further by way of examples. It is not intended to limit the disclosure to the examples and to the embodiments illustrated in these examples.

[0099] Examples, Materials and Methods

[0100] Methods

[0101] Mooney viscosity: The Mooney viscosity (MV) was determined at ML 1+4, 100 °C according to DIN 53523.

[0102] Melt flow index: The melt flow index (MFI) was measured with a MI-3 plastometer from Gbttfert Werkstoff-Prufmaschinen GmbH, Germany, at 210 °C with 21.2 N load and 5 min pre-heating according to DIN EN ISO 1133.

[0103] Glass transition temperature and melting point: The glass transition temperature, Tg, the peak maximum melting temperature, Tm, and the (specific) enthalpy of fusion, AH, were obtained from second heating runs at 10 K / min using according to DIN 53765 using differential scanning calorimetry (DSC).

[0104] Hardness tests: Shore A and D hardness (ShA and ShD) and tensile tests (tensile strength at break (TS) and elongation at break (EaB)) were carried out according to DIN 53505 and DIN 53504, respectively. For the former, pellets were plasticized in an internal mixer (Brabender GmbH & Co. KG, Germany, 85 ml, 100-160 °C, 50 rpm) and 6.3 mm thick slabs were compression molded between PTFE foils for 5 min at 170°C and 120 bar. For the latter, dumbbell-shaped S2 test specimens were injection molded on a micro compounder (Xplore Instruments B.V., The Netherlands). For each compound formulation, five S2 specimens were analysed, and median values were calculated for TS and EaB. The tensile tests of the 3D-printed samples were carried out with the 3D-printed dumbbell-shaped S2 test specimens.

[0105] Gel permeation chromatography: GPC measurements were undertaken with a QS 02808 HT GPC-IR device from Polymer Characterization, S.A., Spain, equipped with a IR5 detector at 150 °C, using 1 ,2-Dichlorobenzene (DCB) as the solvent for the analysis of Luminy L130. The polymer characteristics of Luminy LX 175, EVM Polymer and ENR, GPC measurements were carried out by GPC on an Agilent 1260 Infinity RID device from Agilent Technologies, Inc., with tetrahydrofuran (THF) as solvent at 35 °C (DIN 55672).

[0106] 3D-printing: Dumbbell-shaped S2 test specimens (DIN 53504) were 3D-printed with a Tumaker NX Pro pellet 3D printer from International Technology 3D Printers, S.L., equipped with a nozzle with 0.8 mm diameter. For samples 1-2 and 4-12, the die temperature was set to 210 °C, and for sample 3 to 220 °C. The temperature of the extruder screw and the bed were set to 160 and 70 °C, respectively. 3DLAC spray adhesive from Laboratorios 3D Print, S.L., Spain, was applied to the bed of the printer before printing samples 1-6. No adhesive was applied for printing samples 7 and 10 because adherence of these samples to the bed was sufficient. For samples 1-6, the z stepping height was 1 mm and, for samples 7 and 10, 1.4 mm. The extrusion factor was set to 100 for samples 1-6 and to 120 for samples 4-7 and sample 10. Two layers were printed along the contour line of the test specimen. At the inside of the test specimen, the filaments were arranged at an angle of 45° to the specimen longitudinal axis. The infill density was 100 %.

[0107] Materials

[0108] Polylactic acid (PLA) was purchased from Nordmann, Rassmann GmbH and Resinex Germany GmbH underthe trade designations Luminy LX175, Luminy L130, and Ingeo 4043D. The PLA was dried with hot air in silos from Motan Holding GmbH for 6 to 12 h at 80 °C before use. As is shown in table 1 , the PLAs designated Luminy and Ingeo were obtained from different suppliers and may have a different isomer composition (ratio of L- and D-froms) but were similar for their physical properties such as for example Tg and melting points.

[0109] The EVM Polymer was an epoxy-functionalized ethylene-vinyl acetate copolymer containing 60 wt% by weight of vinyl acetate and 3 wt% of glycidyl methacrylate. The EVM Polymer was stored at 7 °C until use.

[0110] Epoxidized natural rubber (ENR 25) with 25 mol.% epoxidation was purchased from Weber & Schaer, Germany. ENR was stored at room temperature and shredded together with dry ice into pieces with an edge length of 3-6 mm shortly before use.

[0111] Methyltetrahydrophthalic anhydride (MTHPA, CAS # 1 1070-44-3) used as curing agent and tetrabutylammonium bromide used as accelerator (TBAB, CAS # 1643-19-2) were purchased from TCI Deutschland GmbH, Germany.

[0112] Table 1 : properties of the polymers used in the examples.

[0113] ¬ available, n.a.

[0114] #PLA polymer is a semi-crystalline solid at 100 °C; thus ML 1+4 100 °C cannot be measured

[0115] * tested at 190 °C and 21 .2 N

[0116] $measured ShD-hardness was below application limits of test method (30-90 ShD) Table 1 (continued)

[0117] * taken from E. H. Backes, et al., ‘Analysis of the degradation during melt processing of PLA / Biosilicate composites’, J. Compos. Sci. 3, 52 (2019) and thus obtained by a different method than used for the LUMINY grades.

[0118] Examples

[0119] Examples 1 - 12:

[0120] Small pellets were produced from blends of PLA and EVM polymers (examples 1 to 6) and blends of PLA and ENR (comparative examples 7-12) by dynamic vulcanization on a twin screw extruder (ZWE 27 Maxx TSE from Leistritz AG with 28.3 mm screw diameter and 48barrel length to diameter ratio). TBAB and the polymers were fed into the extruder with dosing devices from Brabender GmbH & Co. KG. The MTHPA was added via a syringe pump. The extruder intake area was set to 100 °C, the extruder zones to 200 °C, and the die at 210 °C. For the TPV’s produced with EVM and ENR polymer, the machine adapter was set to 200 and 210 °C, respectively, the screw speed to 100 rpm, resulting in a mass throughput of 8 kg I h, and 230 and 215 °C mass temperature, respectively. The melt was pelletized with an underwater granulator unit from Maag Germany GmbH at 40 °C water temperature and 1 .900 rpm blade speed. The pellet diameter was 3-4 mm. The pellets were subjected to 3D-printing to print dumbbell-shaped S2 test specimens (DIN 53504) with a pellet 3D printer as described above. The ingredients for making the granules for 3D-pri ntin g are shown in tables 2 (examples 1-6) and 3 (examples 7-12). The mechanical properties of the granules are shown in tables 4 for examples 1-6 and in table 5 for comparative examples 7-12. The properties of samples obtained by 3D-printing are shown in table 7 for example 1-6 and in table 8 for comparative examples 7-12. Table 6 shows the properties of 3D-printed samples obtained from using the PLA polymers alone. Table 2: Composition of compounds for producing TPV’s according to examples 1 to 6.

[0121] Table 3: Composition of compounds with ENR for producing TPV’s (examples 7-12).

[0122] Table 4: Mechanical properties of TPV’s used as feedstock for 3D-printing (examples 1-6). Tg(1> and Tg(2 )denote the first and second glass transition temperatures obtained in the second DSC heat runs. Table 5: Mechanical properties of TPV’s obtained with functionalized NR (ENR) instead of functionalized EVM and used as feedstock for 3D-printing (examples 7-12).

[0123] Tg<1> and Tg<2> denote the first and second glass transition temperatures obtained in the second DSC heat runs.

[0124] Table 6: Tensile properties of 3D-printed samples obtained with PLA only (comparative).

[0125] Table 7: Tensile properties of 3D-printed samples obtained with the TPV’s produced in examples 1-6.

[0126] Table 8: Tensile properties of 3D-printed samples obtained with the TPV’s produced in examples 7-12 with functionalized NR(ENR).

[0127] $The extruded filaments do not adhere to each other and an object could not be printed.

[0128] Examples 13 and 14 (comparative)

[0129] Using the twin screw extruder machine and underwater granulator unit described above, granules 3-4 mm in diameter were prepared from blends containing only PLA (INGEO 4043D) and the EVM Polymer of the examples above but no curing system and, therefore, the blends were not cured and were not TPV’s. The ingredients for making the granules for 3D-printing are shown in table 9. The properties of the granules are shown in table 10. The granules were subjected to 3D-printing to produce dumbbell-shaped S2 test specimens (DIN 53504) in a pellet 3D printer as described above. The properties of the 3D printed samples are listed in table 11.

[0130] Table 9: Composition of compounds for producing blends of PLA and functionalized EVM without curing (comparative examples 13 and 14).

[0131] Table 10: Mechanical properties of blends used as feedstock for 3D-printing (examples 13 and 14).

[0132] * tested at 190 °C and 21.2 N, Tg(1 )and Tg(2 )denote the first and second glass transition temperatures obtained in the second heat run. Table 11 : Tensile properties of 3D-printed samples obtained with the blends produced in examples 13 and 14.

[0133] A comparison of table 11 with table 7 shows that the articles produced with the TPV’s of examples 1-6 (obtained by curing of the functionalized EVM in the presence of the thermoplastic polymer) have a much higher elasticity than those obtained by blending the thermoplastic polymer with the functionalised EVM without using a curing system. The articles produced in examples 1-6 (table 7) have an elasticity (elongation at break) of greater than 90% and therefore, can be regarded to be elastic articles.

Claims

Claims1 . A 3D-printable composition in the form of a filament, a granule or a plurality thereof wherein the 3D-printable composition comprises a polymer composition that comprises at least one thermoplastic polymer comprising a polylactic acid and at least one cross-linked functionalized elastomer having at least one functional group that is cross-linked and wherein the elastomer is an ethylene-vinylacetate polymer comprising units derived from ethylene and vinylacetate.

2. The 3D-printable composition of claim 1 wherein the filament is an elongated article and has a diameter of from 1 to 12, preferably from 1 to 5 mm, and a length of at least 50 mm, preferably at least 3 m and wherein the granule has a diameter of up to 100, preferably up to 13 mm and a length of less than 50, preferably less than 23 mm.

3. The 3D-printable composition according to any one of the preceding claims having a tensile strength of at least 5 MPa when tested according to DIN 53504 and a peak maximum melting temperature, Tm, obtained from the second heating run at 10 K / min according to DIN 53765 using differential scanning calorimetry (DSC) of 110°C to 280° C and an elongation at break of at least 50% when tested according to DIN 535044. The 3D- printable composition according to any one of the preceding claims having a tensile strength of at least 7 MPa as determined according to DIN 53504 and a peak maximum melting temperature, Tm, obtained from the second heating run at 10 K / min when tested according to DIN 53765 using differential scanning calorimetry (DSC), from 110°C to 280° C and either having an elongation at break of at least 50% or at least 100%, when tested according to DIN 53504, or a melt flow index (MFI) at 210°C and 21.2 N load of at least 1 g / 10 min, when tested according to DIN EN ISO 1133, or both.

5. The 3D-printable composition according to any one of the preceding claims wherein the at least one cross-linked functional group is comprises a cross-linked unit selected from an anhydride unit, epoxide unit, a combination thereof or a plurality thereof.

6. The 3D-printable composition according to any one of the preceding claims comprising at least 50% by weight, preferably at least 75% by weight, more preferably at least 95% by weight of the polymer composition, wherein the % by weight is based on the total weight of the 3D-printable composition which is 100%.

7. The 3D-printable composition according to any one of the preceding claims wherein either the ethylene or the vinyl acetate or both are obtained from a sustainable source selected from a plant-based source, a recycled material or a combination thereof.

8. A spool comprising, wound up onto it, at least one filament according to any one of the preceding claims.

9. A process of producing an article comprising providing a 3D-printable composition according to any one of claims 1 to 7 or a plurality thereof and subjecting it to 3D-pri nting in at least one 3D-printer suitable for printing filaments or granules to create at least one shaped article.

10. An article comprising at least a component obtained by the process of claim 9.

11. A process for making a 3D-printable composition according to any one of claims 1 to 7 comprising a step (i) comprising providing a polymer composition comprising of mixture of (a) at least one thermoplastic polymer comprising a polylactic acid, and (b) at least one elastomer, wherein the elastomer is an ethylene-vinylacetate polymer comprising units derived from ethylene and vinylacetate and is functionalised to comprise at least one functional group that can be cross-linked in a curing reaction and, optionally, (c) at least one curing agent for cross-linking the functional group; a step (ii) comprising forming the polymer composition into a filament, a granule or a plurality thereof, a step (iii) comprising subjecting the polymer composition to curing, optionally, in the presence of a curing agent, wherein step (iii) is carried out before, during or after step (ii).

12. The process of claim 11 wherein the ethylene-vinylacetate polymer comprises at least 10 % by weight, based on the total weight of the elastomer, of units derived from ethylene, from 40 % to 90 % by weight, based on the total weight of the elastomer, of units derived from vinyl acetate and from 0-30 % by weight, based on the total weight of the elastomer, of units derived from at least one further comonomer.

13. The process according to any one of claims 11 or 12 wherein the at least one functional group that can be cross-linked in a curing reaction comprises an anhydride, an epoxide, a combination thereof or a plurality thereof.

14. The process according to any one of claims 11 to 13, wherein the functional group corresponds to the general formulae (1) or (2):wherein in formula (1)R1 represents a chemical bond or a Ci-C6alkyl, a Ci-C6halogenated alkyl, a Ci-C6hydroxy alkyl, a Ci-C6alkyl ether or a polyether with 3 to 12 C-atoms,R2 represents a -CH2- group of which one hydrogen atom, optionally, may be substituted with a halogen, a Ci-C6alkyl, a Ci-C6halogenated alkyl, a Ci-C6hydroxy alkyl, a Ci-C6alkyl ether or polyether,R3 is a -CH2- group of which one hydrogen atom, optionally, may be substituted with a halogen, a C2-C6alkylene or alkylalkylene, a Ci-C6halogenated alkylene or alkylalkylene, a Ci-C6hydroxy alkylene or alkylalkylene, a C3-C6alkylene ether or alkyetheralkylene or alkyletheretheralkylene and wherein in formula (2) m is either 0 or 1 ;X is O, O(CR2)P, (CR2)PO, C(=O)O, C(=O)O(CR2)P, C(=O)NR, (CR2)P, N(R), N(R)(CR2)P, P(R), P(R)(CR2)P, P(=O)(R), P(=O)(R)(CR2)P, S, S(CR2)P, S(=O), S(=O)(CR2)P, S(=O)2(CR2)Por S(=O)2, wherein R is H or a linear or branched hydrocarbon group having from 1 bis 13 carbon atoms that may comprise one or more O-atom, in addition carbon and hydrogen atoms;Y represents a divalent unit derived from a mono- or polyunsaturated monomer having from 2 to 20 carbon atoms selected from conjugated or non-conjugated dienes, alkynes and vinyl compounds, or Y represents a divalent unit having from 2 to 10 carbon atoms and one or more heteroatoms in addition to hydrogen atoms, wherein the heteroatoms are selected from O, Si and N and combinations thereof, preferably Y is selected from polyalkylene glycol ethers, polyalkylene oxides,polysiloxanes, polyols, polycarbonates, polyurethanes, polyisocyanates, polysaccharides, polyesters and polyamides, n and p are the same or different and are each in the range of 0 to 10 000, preferably 0 to 100 and especially preferably n is in the range from 0 to 100 and at the same time p = 0,R4, R5and R6are identical or different and represent H or a C1-C3 alkyl, preferably at least two and more preferably all of R4, R5and R6represent H.

15. The process according to any one of claims 11 to 14 wherein the thermoplastic polymer comprising the polylactic acid has a melting point of from 110 to 280°C and, optionally, a melt flow index (MFI at 210 °C with 21.2 N load) of from 1 to 100 g / 10 min, preferably from 2 to 57 g / 10 min.

16. The process according to any one of claims 11 to 15 wherein the curable polymer composition is obtained by dispersing the functionalised ethylene-vinylacetate elastomer in the thermoplastic polymer at conditions where the thermoplastic polymer is in a molten form.

17. The process according to any one of claims 11 to 16 wherein the ethylenevinylacetate polymer comprises at least one further comonomer selected from an alphaolefin that is functionalized to bear the at least one functional group that can be cross-linked in a curing reaction.

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