Oil-extended ethylene copolymers

Abstract

A polymer composition having a Mooney viscosity ML, 1+4, at 100°C of at least 45 Mooney units and comprising at least 90% and up to 100% by weight, based on the weight of the total composition, of an oil-extended ethylene-propylene copolymer comprising from 38% to 70% by weight, of units derived from ethylene, further comprising units derived from propylene and, optionally, at least one further comonomer, wherein the oil-extended copolymer comprises from 20 parts to 150 parts per hundred parts of copolymer of an extender oil having a flash point of greater than 220°C (DIN EN ISO 2592) and a paraffinic content as determined according to ASTM 3238 of greater than 70% wherein, preferably, at least a portion of the extender oil is obtained from a sustainable carbon source. Also provided are a process for producing the polymer composition, a process for making a curable polymer composition, an article comprising the reaction product of a curing reaction comprising polymer composition as reactant. Further provided are compositions for making a thermoplastic vulcanizate and a process for producing a thermoplastic vulcanizate, and thermoplastic vulcanizates.

Description

[0001] Oil-Extended Ethylene Copolymers

[0002] Background

[0003] The mechanical properties of ethylene-propylene rubbers like EPDM rubbers can be improved by increasing the molecular weight of the polymer. However, rubbers with high molecular weight, and thus high Mooney viscosities, tend to be difficult to process. Adding oil reduces the Mooney viscosity of the polymer. An oil-extended polymer typically has a lower Mooney viscosity than a polymer of the same molecular weight that is not oil- extended. Oils can be blended with the polymers by dry or wet blending to produce oil- extended polymers. There is a need to provide sustainable oil-extended polymers using either polymers or oils or both from sustainable sources that are compatible.

[0004] Summary

[0005] In one aspect there is provided a polymer composition having a Mooney viscosity ML, 1+4, at 100°C of at least 45 Mooney units and comprising at least 90% and up to 100% by weight, based on the weight of the total composition, of an oil-extended ethylene-propylene copolymer comprising from 38% to 70% by weight, of units derived from ethylene, further comprising units derived from propylene and, optionally, at least one further comonomer, wherein the oil-extended copolymer comprises from 20 parts to 150 parts per hundred parts of copolymer of an extender oil having a flash point of greater than 220°C (DIN EN ISO 2592) and a paraffinic content as determined according to ASTM 3238 of greater than 70% wherein, preferably, at least a portion of the extender oil is obtained from a sustainable carbon source.

[0006] In another aspect there is provided a process for producing the polymer composition comprising:

[0007] (i) polymerizing the ethylene with the propylene and, optionally, one or more further copolymerizable comonomers, in at least one solvent to produce a reaction mixture comprising the at least one solvent and an ethylene-propylene copolymer comprising from 38% to 70% by weight, based on the total weight of the polymer, of units derived from ethylene, and having a Mooney viscosity ML 1+8, 150°C of at least 35 Mooney units;

[0008] (ii) adding from 20 parts to 150 parts of extender oil to the reaction mixture and blending it with the copolymer, wherein the extender oil has a flash point of greater than 220°C (DIN EN ISO 2592) and a paraffinic content as determined according to ASTM 3238 of greater than 70% and wherein, preferably, at least a portion of the extender oil is obtained from a sustainable carbon source,

[0009] (iii) removing the solvent.

[0010] In a further aspect there is provided a process for making a curable polymer composition comprising combining the polymer composition with at least one curing agent for curing the ethylene-propylene copolymer.

[0011] In another aspect there is provided an article comprising the reaction product of a curing reaction comprising as reactants the polymer composition and at least one curing agent for curing the copolymer.

[0012] In a further aspect there is provided a composition for making a thermoplastic vulcanizate, TPV, comprising the polymer composition a thermoplastic resin, preferably selected from a polypropylene, a polyethylene or a combination thereof, and a curative.

[0013] In another aspect there is provided a process for producing a thermoplastic vulcanizate, TPV, comprising blending the polymer composition, a thermoplastic resin, preferably selected from at least one polypropylene, at least one polyethylene or a combination thereof, and a curative, and subjecting the blend to dynamic curing, preferably in an extruder, wherein, preferably, the polymer composition is blended with the thermoplastic resin above the melt temperature of the resin before the curative is added to the blend.

[0014] In a further aspect there is provided a thermoplastic vulcanizate, TPV, obtained from the process.

[0015] Detailed Description

[0016] 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, then the version is referred to that was in force at a date that is closest to March 1 , 2020.

[0017] 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 used interchangeably and are based on the total weight of the composition or polymer, respectively, which is 100 % unless indicated otherwise. When amounts of units derived from a monomer or other ingredients of the polymer are expressed in % by weight based on the weight of copolymer and the copolymer is oil-extended the total weight of the copolymer still refers to the total weight of the copolymer. In other words, the total weight of copolymer of an oil-extended copolymer is the weight of the copolymer and the extender oil minus the weight of the extender oil.

[0018] The term “phr” means parts per hundred parts of rubber.

[0019] Ranges identified in this disclosure include and disclose all values between the endpoints of the range and include the end points unless stated otherwise.

[0020] The words “comprising” and “containing” are used interchangeably. They are used in a nonlimiting meaning. They are meant to include the ingredients or components to which they refer but do not exclude the presence of other ingredients or components. For example, a composition comprising components A and B includes the components A and B but may also include additional components other than A or B. Contrary to the words “comprising” or “containing”, the word “consisting of’ is used in a limiting sense. For example, a composition consisting of components A and B is meant to describe a composition that has no other components than components A and B.

[0021] Polymer compositions

[0022] The polymer compositions according to the present disclosure comprise at least one oil- extended ethylene-propylene copolymer. Typical ethylene-propylene copolymers include EPM and EPDM rubbers. Typically, the polymer compositions consist essentially of ethylene-propylene copolymer and oil and may contain residual amounts from ingredients used in the polymerization reaction and / or additives added during or after the work up procedure, for example stabilizers, like antioxidants. Therefore, the polymer compositions comprise at least 90% by weight and preferably up to 95% by weight and may comprise up to 99% or may even consist of up to 100% by weight of ethylene-copolymer and extender oil (the weight percentages are based on the total weight of the composition which is 100%). Typically, the oil-extended copolymer composition comprises from 20 to 120 parts per 100 parts of ethylene-propylene copolymer of oil. In one embodiment of the present disclosure the composition comprises from 30 to 100 or from 30 to 50 parts of extender oil per 100 parts of copolymer. Typically, the polymer composition has a Mooney viscosity ML, 1+4, at 100°C of at least 45 Mooney units, or at least 50 Mooney units. The compositions may have a Mooney viscosity ML 1 +8 at 150°C of 95. Preferably, the polymer composition has a weight loss of less than 0.05g, preferably less than 0.043g / g extender oil when subjecting it to a heat treatment test defined as follows: a) blending the polymer composition on a two-roll mill at 50°C with 4 phr zinc oxide, 1 .5 phr stearic acid, 1.8 phr N-cyclohexyl-2-benzothiazylesulphenamide and 1 phr sulfur to produce a sheet of curable compound having a thickness 2 mm, b) subjecting the sheet to curing for 30 min at 180°C according to ISO 5602 c) cutting S2-dumbbells from the cured sheets and subject them to heat treatment in dry air according to DIN 53521 at 135°C for 168 hours, d) determining the difference in mass of the cured sheet before and after the heat treatment. Typically, 500 g of polymer composition are needed for making the heat treatment test. The median from 3 measurements is taken.

[0023] Preferably, at least a portion of the oil, the propylene, the ethylene, or a combination thereof, is obtained from a sustainable carbon source. Preferably, the sustainable carbon source is either a recycled material or a bio-based, typically plant-based, material or both. Therefore, an oil-extended polymer can be provided that is made predominantly or even exclusively with materials from a sustainable source. For example, in one embodiment more than 50% by weight, or even more than 75% by weight or even more than 95% by weight of the ingredients of the polymer composition are obtained from a sustainable carbon source, which may in fact be different sustainable carbon sources. Such materials will lower the C02-footprint of the polymer compositions and will reduce the C02-footprint of articles made from them. In one embodiment of the present disclosure the polymer composition, the extender oil, the ethylene-propylene copolymer or a combination thereof is obtained from a material of biological origin, such as a plant-based material. Typically, materials of biological origin, like plant-based materials, have a higher C14-content than materials obtained from fossil sources. Therefore, in one embodiment of the present disclosure the polymer composition has a carbon 14 content as determined by ASTM D6866-18 Method B of at least 5%, preferably at least 15%, more preferably at least 25% or even more than 50% based on the total carbon content, of the composition. Recycled monomers, in particular ethylene but also other alpha-olefin comonomers, such as propylene, may be obtained by the pyrolysis or cracking of carbon-containing waste materials, including but not limited to tires, plastic waste, hydrocarbon-containing waste material such as wood pulp or biomass. They may be used in a so-called mass-balanced process to reduce the overall C02-content of the production chain (see for example, Pete Spanos et al, “Sustainable Keltan EPDM”, RUBBERWORLD.COM, April 2023). Examples of bio-based materials that may be used as sustainable source of carbon include plant-based materials selected from sugar canes, sugar beets, maple, date palm, corn, wheat, barley, sorghum, rice, potato, cassava, sweet potato, algae, materials comprising cellulose, wine, materials comprising hemicelluloses, materials comprising lignin, wood, straw, sugarcane bagasse, sugarcane leaves, corn stover, wood residues, paper, and combinations thereof. Ethylene, for example, may be obtained by fermentation of plant-based material to produce ethanol, which subsequently is dehydrated to produce ethylene. Such processes are known and described, for example in US11267959B2. The polymerization for making ethylene-propylene polymers typically involves catalysts, either of the Ziegler-Natter-type of catalyst based on metallo-organic complexes such as metallocene-type catalysts or post metallocene-type catalysts. Ethylene and other comonomers obtained from a sustainable source may be purified before they are contacted with the polymerization catalysts to remove substances that could poison or reduce the activity of the polymerization catalyst. Purification of the monomer streams may be carried out as known to the persons skilled in the art, for example by removing CO, metals, alcohols and other oxygen-containing hydrocarbons, higher alkenes, sulfur compounds and combinations thereof, for example by using absorbents prior to feeding the monomers streams to the polymerization reactor or by using scavengers in the polymerization reaction as is known in the art. Further efforts may be taken to remove higher alcohols, higher alkenes, oxygen-containing hydrocarbons, sulfur-containing hydrocarbons from the monomer feeds etc., for example, by distilling the ethylene streams or by feeding the streams over absorbents, like resins, active carbon filters. However, it has been found that Ziegler-Natter catalysts and metalloorganic catalysts like the ACE catalyst (see for example, Martin van Duin et al, “Defining EPDM for the past and next 50 years”, Kautschuk Gummi Kunststoffe, 11-12, 2017) are robust enough to produce EPDM polymers with monomers obtained from mass-balance or biological sources like sugar canes etc. without reduced efficiency.

[0024] Therefore, in one embodiment of the present disclosure there is provided a polymer composition having a weight loss of less than 0.05 g / g of extender oil present in the polymer composition, preferably less than 0.043g per g of extender oil present in the polymer composition, when carrying out a heat treatment test as follows: a) blending the polymer composition on a two-roll mill at 50°C with 4 phr zinc oxide, 1 .5 phr stearic acid, 1.8 phr N-cyclohexyl-2-benzothiazylesulphenamide and 1 phr sulfur to produce a sheet of curable compound having a thickness 2 mm, b) subjecting the sheet to curing for 30 min at 180°C according to ISO 5602 c) cutting S2-dumbbells from the cured sheets and subject them to heat treatment in dry air according to DIN 53521 at 135°C for 168 hours, d) determining the difference in mass of the cured sheet before and after the heat treatment, and wherein the polymer composition has a carbon 14 content (14C-content) as determined by ASTM D6866-18 Method B of at least 5%, preferably at least 15%, more preferably at least 25% or even more than 50% based on the total carbon content, of the polymer composition. Preferably, at least a portion of the propylene, at least a portion of the ethylene, or at least a portion of the oil, or a combination thereof, is obtained from a sustainable carbon source. Preferably, the sustainable carbon source is either a recycled material or a plant-based material or a combination thereof.

[0025] Ethylene-propylene copolymers

[0026] An ethylene-propylene copolymer that can be used to make the polymer compositions according to the present disclosure is a copolymer of ethylene, propylene, and, optionally, at least one further comonomer. The copolymer may comprise from 38% to 70%, based on the weight of the polymer of units derived from ethylene. In one embodiment of the present disclosure the copolymer comprises from 41 % to 61 % weight or from 49 to 59% by weight of units derived from ethylene. In one embodiment of the present disclosure the copolymer comprises up to 56 % by weight or up to 52 % by weight of units derived from ethylene. In one embodiment the copolymer of the present disclosure comprises from 52% to 70% by weight or from 54% to 65% by weight, or from 57% to 68% by weight of units derived from ethylene. Preferably, the ethylene-propylene copolymer contains at least 14 % by weight of units derived from propylene.

[0027] Further comonomers

[0028] In addition to units derived from ethylene and propylene, the copolymer according to the present disclosure, optionally, has repeating units derived from one or more further comonomers. Suitable further comonomers include C4-C20-a-olefins, non-conjugated dienes and combinations thereof.

[0029] C4-C20-a-olefins:

[0030] C4-C20-a-olefins (also referred to herein as” C4-C20alpha olefins”) are olefins containing from four to twenty carbon atoms and having a single aliphatic carbon-carbon double bond. The double bond is located at the terminal front end (alpha-position) of the olefin. The a- olefins can be aromatic or aliphatic, linear, branched or cyclic. Examples include but are not limited to 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1 -tetradecene, 1-pentadecene, 1-hexadecene, 1-hepta-decene, 1 -octadecene, 1 -nonadecene, 1-eicosene, 3-methyl-1 -butene, 3-methyl-1 -pentene, 3-ethyl- 1 -pentene, 4-methyl-1 -pentene, 4-methyl-1 -hexene, 4, 4-dimethyl-1 -hexene, 4,4-dimethyl- 1-pentene, 4-ethyl-1 -hexene, 3-ethyl-1 -hexene, 9-methyl-1 -decene, 11-methyl-1 -dodecene and 12-ethyl-1 -tetradecene. The alpha olefins may be used in combination.

[0031] Non-conjugated dienes:

[0032] Non-conjugated dienes are polyenes comprising at least two double bonds, the double bonds being non-conjugated in chains, rings, ring systems or combinations thereof. The polyenes may have endocyclic and / or exocyclic double bonds and may have no, the same or different types of substituents. The double bonds are at least separated by two carbon atoms. The non-conjugated dienes are preferably aliphatic, more preferably alicyclic and aliphatic. Suitable non-conjugated dienes include aromatic polyenes, aliphatic polyenes and alicyclic polyenes, preferably polyenes with 6 to 30 carbon atoms (C6-C3o-polyenes, more preferably C6-C3o-dienes). Specific examples of non-conjugated dienes include 1 ,4- hexadiene, 3-methyl-1 ,4-hexadiene, 4-methyl-1 ,4-hexadiene, 5-methyl-1 ,4-hexadiene, 4- ethyl-1 ,4-hexadiene, 3,3-dimethyl-1 ,4-hexadiene, 5-methyl-1 ,4-heptadiene, 5-ethyl-1 ,4- heptadiene, 5-methyl-1 ,5-heptadiene, 6-methyl-1 ,5-heptadiene, 5-ethyl-1 ,5-heptadiene, 1 ,6-octadiene, 4-methyl-1 ,4-octadiene, 5-methyl-1 ,4-octadiene, 4-ethyl-1 ,4-octadiene, 5- ethyl-1 ,4-octadiene, 5-methyl-1 ,5-octadiene, 6-methyl-1 ,5-octadiene, 5-ethyl-1 ,5- octadiene, 6-ethyl-1 ,5-octadiene, 1 ,6-octadiene, 6-methyl-1 ,6-octadiene, 7-methyl-1 ,6- octadiene, 6-ethyl-1 ,6-octadiene, 6-propyl- 1 ,6-octadiene, 6-butyl-1 ,6-octadiene, 4-methyl- 1 ,4-nonadiene, 5-methyl-1 ,4-nonadiene, 4-ethyl-1 ,4-nonadiene, 5-ethyl-1 ,4-nonadiene, 5- methyl-1 ,5-nonadiene, 6-methyl-1 ,5-nonadiene, 5-ethyl-1 ,5-nonadiene, 6-ethyl-1 ,5- nonadiene, 6-methyl-1 ,6-nonadiene, 7-methyl-1 ,6-nonadiene, 6-ethyl-1 ,6-nonadiene, 7- ethyl-1 ,6-nonadiene, 7-methyl-1 ,7-nonadiene, 8-methyl-1 ,7-nonadiene, 7-ethyl-1 ,7- nonadiene, 5-methyl-1 ,4-decadiene, 5-ethyl-1 ,4-decadiene, 5-methyl-1 ,5-decadiene, 6- methyl-1 ,5-decadiene, 5-ethyl-1 ,5-decadiene, 6-ethyl-1 ,5-decadiene, 6-methyl-1 ,6- decadiene, 6-ethyl-1 ,6-decadiene, 7-methyl-1 ,6-decadiene, 7-ethyl-1 ,6-decadiene, 7- methyl-1 ,7-decadiene, 8-methyl-1 ,7-decadiene, 7-ethyl-1 ,7-decadiene, 8-ethyl-1 ,7- decadiene, 8-methyl-1 ,8-decadiene, 9-methyl-1 ,8-decadiene, 8-ethyl-1 ,8-decadiene, 1 ,5,9-decatriene, 6-methyl-1 ,6-undecadiene, 9-methyl-1 ,8-undecadiene, dicyclopentadiene, and combinations thereof.

[0033] Further examples of non-conjugated dienes include dual polymerizable dienes. Dual polymerizable dienes include vinyl substituted aliphatic monocyclic and non-conjugated dienes, vinyl substituted bicyclic and unconjugated aliphatic dienes, alpha-omega nonconjugated dienes. Dual polymerizable dienes may cause or contribute to the formation of polymer branching. Specific examples include 1 ,4-divinylcyclohexane, 1 ,3- divinylcyclohexane, 1 ,3-divinylcyclopentane, 1 ,5-divinylcyclooctane, 1 -allyl-4-vinylcyclo- hexane, 1 ,4 diallyl cyclohexane, 1-allyl-5-vinylcyclooctane, 1 ,5-diallylcyclooctane, 1-allyl-4- isopropenyl-cyclohexane, 1-isopropenyl-4-vinylcyclohexane and 1-isopropenyl-3- vinylcyclopentane, dicyclopentadiene and 1 ,4-cyclohexadiene. Preferred are nonconjugated vinyl norbornenes and C8-Ci2alpha omega linear dienes. The dual polymerizable dienes may be further substituted with at least one group comprising a heteroatom of group 13-17 for example O, S, N, P, Cl, F, I, Br, or combinations thereof. Examples of aromatic non-conjugated polyenes include vinylbenzene (including its isomers) and vinyl-isopropenyl benzene (including its isomers).

[0034] Preferred non-conjugated dienes include alicyclic polyenes. Alicyclic dienes have at least one cyclic unit. In a preferred embodiment the non-conjugated dienes are selected from polyenes having at least one endocyclic double bond and optionally at least one exocyclic double bond.

[0035] Preferred examples include dicyclopentadiene (DCPD), 2,5-norbornene, 5-vinyl-2- norbornene (VNB), 1 ,7-octadiene, 1 ,9-decadiene, 5-vinyl-2-norbornene (VNB) 5- methylene-2-norbornene and 5-ethylidene-2-norbornene (ENB) and combinations thereof.

[0036] In one embodiment the copolymer of the present disclosure contains only ENB as further comonomer.

[0037] In one embodiment the copolymer of the present disclosure contains only VNB as further comonomer.

[0038] In one embodiment the copolymer of the present disclosure contains only DCPD as further comonomer.

[0039] In one embodiment the copolymer of the present disclosure contains only ENB and VNB as further comonomer.

[0040] In one embodiment the copolymer of the present disclosure contains only ENB, VNB or DCPD or a combination thereof as further comonomer.

[0041] In a typical embodiment of the present disclosure the copolymer contains at least 3 wt. % and up to and including 20 wt. % of units derived from the one or more further comonomer. In another preferred embodiment, the copolymer contains from 3 to 18 wt. % of units derived from the one or more further comonomers, more preferably from 7 to 18 wt. %, for example from 8 to 15 wt. %. In a preferred embodiment the copolymer contains from 3 wt. % and up to 20% wt. % of units derived from ENB, and, more preferably from 6 to 18 wt. % of units derived from ENB, from 7 to 17 wt. %, or from 8 to 15 wt. %, of units derived from ENB (all wt.% based on the total weight of the copolymer). In one embodiment, the copolymer of the present disclosure contains from 0 wt. % to 5 wt. %, more preferably from 0.10 wt. % to 3 wt. %, or from 0.2 wt. % to 1 .2 wt. % of units derived from VNB.

[0042] The ethylene-propylene copolymer according to the present disclosure may have an ENB content per polymer chain of at least 10, at least 20, at least 30, at least 40, at least 50, or at least 60. In one embodiment of the present disclosure the ethylene copolymer according to the present disclosure has an ENB content per polymer chain of from about 55 up to about 125.

[0043] The ethylene-propylene copolymers used for making the polymer compositions according to the present disclosure preferably have a high Mooney viscosity, for example a Mooney viscosity ML 1+8 at 150°C of at least 35 Mooney units, preferably at least 45 or at least 55 Mooney units. The copolymers may have Mooney viscosities up to 200 Mooney units or above 200 Mooney units, which means the Mooney viscosity cannot be measured anymore.

[0044] The ethylene-propylene copolymers used for making the polymer compositions according to the present disclosure preferably have a weight average molecular weight (Mw) of at least 100,000 g / mol and up to 1 ,000.000 g / mol. In one embodiment the copolymers have an Mw of at least 250,000 g / mol and more preferably at least 300,000 g / mol. In one embodiment the copolymers may have an Mw from 350,000 g / mol and up to 700,000 g / mol. In one embodiment of the present disclosure the number-averaged molecular weight (Mn) of the ethylene-copolymers may be from about 25 to 500 kg / mol, or from 40 to 230 kg / mol, or from 65 to 165 kg / mol. The ethylene copolymer of the present disclosure preferably may have a molecular weight distribution (Mw / Mn), of at least 2.0, for example from 2.3 to 4.5 or from 3.5 to 25 or from 3.7 to 10. Preferably, the ethylene copolymers according to the present disclosure are branched, for example with a branching level of AS between 2 and 60 degrees, more preferably with a AS between 15 and 55 degrees or between 8 to 50 degrees. AS is expressed in degrees and is the difference between the phase angle 8 at a frequency of 0.1 rad / s and the phase angle 8 at a frequency of 100 rad / s, as determined by Dynamic Mechanical Spectroscopy (DMS) at 125 °C. Copolymer preparation

[0045] The copolymers according to the present disclosure can be prepared by a process comprising copolymerizing ethylene, propylene and, optionally, at least one further comonomer as known in the art of producing ethylene-copolymers. The polymers may be produced by using conventional catalysts, like for example Ziegler-Natta-catalysts or metallocene-type catalysts or a combination of catalysts. Ziegler-Natta catalysts are nonmetallocene type catalysts based on halides of transition metals, in particular titanium or vanadium. Metallocene-type catalysts are organometallic catalysts wherein the metal is bonded to at least one cyclic organic ligand, preferably at least one cyclopentadienyl or at least one indenyl ligand. In one embodiment a Ziegler-Natta catalyst is used. In another embodiment, preferably a metallocene-type catalyst is used. In another embodiment a combination of two or more metallocene-type catalysts is used.

[0046] The polymerization can be carried out in the gas phase, in a slurry, or in solution in an inert solvent, preferably a hydrocarbon solvent. The polymerization may be carried out continuously, for example in one or more continuously stirred tank reactors, one or more loop rectors, or as a batch reaction in one or more batch reactors or a combination thereof. The continuous reaction may be carried out adiabatically or non-adiabatically. Multiple reactors may be used and may be connected in series or in parallel. Solvents and monomers may be chilled prior to entering the reaction for temperature control. Monomers may be evaporated for temperature control.

[0047] Preferably, the polymerization is carried out as solvent polymerization. Preferred solvents include one or more hydrocarbon solvent. Suitable solvents include C5-12 hydrocarbons such as pentane, hexane, heptane, octane, cyclohexane, methylcyclohexane, pentamethyl heptane, hydrogenated naphtha, isomers and mixtures thereof. The polymerization may be conducted at temperatures from 10 to 250 °C, depending on the product being made. Most preferably the polymerisation is performed at temperatures greater than 50 °C, if performed in solution.

[0048] In a preferred embodiment the polymerization includes the use of one or more chain transfer agent to control the molecular weight of the polymer. A preferred chain transfer agent includes hydrogen (H2). The diene content per polymer chain can be controlled, for example, by controlling the amount of dienes in the reaction and the molecular weight (chain length) as known in the art. Branching can be introduced as known in the art, for example by using specific catalysts, for example vinyl group creating catalysts, or by using monomers that create polymer branching, for example dual polymerizable dienes or by using a combination of both. The degree of branching can be controlled, for example, by adjusting their amounts or feed streams during the polymerization as is known in the art.

[0049] Extender oils and oil-extension

[0050] The oil-extended copolymers are preferably obtained by blending one or more extender oils with the copolymer to obtain a homogeneous blend. Blending can be carried out by dry blending or by wet blending. Dry blending involves mixing the (isolated) polymer and the oil. Preferably, the oil-extension is carried out by wet blending. Preferably, the oil is added to the reaction mixture from the polymerization reaction containing the produced copolymer and is blended with the copolymer, preferably prior to working up the polymer, more preferably prior to removing the solvent.

[0051] Preferably, the extender oil preferably has a paraffin content of at least 70%, preferably at least 90%, more preferably at least 95%. The paraffin content can be determined according to ASTM 3238, which for the meaning of the present application can also be applied to oils that are not petroleum-based. Preferably, the oil is a paraffinic oil and preferably is based on linear or branched hydrocarbons or mixture of linear and branched hydrocarbons. Preferably, the combined amount of hydrogen and carbon of the oil is at least 90%, preferably at least 99%. Preferably, the extender oil has a kinematic viscosity of 50 to 150 mm2 / s at 40°C, preferably from 55 to 75 mm2 / s (determined according to DIN EN ISO 3104). Preferably, the oil used for the oil-extension has a kinematic viscosity at 100°C of at least 5 mm2 / s, preferably from 8 to 35, or from 9 to 25 mm2 / s (determined according to DIN EN ISO 3104). Preferably, the extender oil is from a sustainable carbon source. More preferably, the oil is plant-based. Typically, plant-based materials, including terpenes are subjected to hydrogenation to remove unsaturations. Plant-sourced oils are commercially available from various suppliers. Typically, plant-sourced oils have a lower refractive index than mineral oils. Preferably, the oil used as extender oil in the present disclosure has a refractive index of not more than 1.47 at 20°C (determined according to DIN EN ISO 51423-02), more preferably not more than 1 .470. Preferably, the oil has a flash point of greater than 220°C, preferably greater than 250°C or at least 260°C (DIN EN ISO 2592). Preferably, the oil is predominantly or essentially fully saturated. Predominantly, as referred to herein means less than 10% of unsaturated hydrocarbons are present. The degree of saturation can be determined by the iodine number. Materials having an iodine number of less than 1g l2 / 100g are considered herein as “essentially fully saturated”. Preferably, the oil has an iodine number of 0.5g l2 / 100g or less. The iodine number can be determined, for example, by titration according to the Wijs method, see for example Metrohm Application Note H-076 (AN-H-076, www.metrohm.com). Preferably, the oil has a glass transition temperature of less than -70°C. The glass transition temperature (Tg) can be determined, for example, according to DIN 53765.

[0052] Rubber compounds

[0053] The ethylene-propylene copolymers are typically provided by rubber manufactures in the form of bales. Such bales typically have a length of at least 30 cm, a width of at least 20 cm and a height of at least 10 cm. The bales are typically sold to rubber compounders. The compounders blend the rubber with additives to produce so-called rubber compounds. The rubber compounds typically are prepared by blending the ingredients in a kneader or on a mill. Such compounds typically contain from 10 to 50% by weight of rubber and the remainder includes fillers, curatives, processing additives, such as processing oil and other additives tailored to the article to be produced by subjecting the rubber compound to curing and shaping. To increase the content of bio-based materials of rubber compounds and to reduce the CO2footprint of articles made from rubber compounds, ingredients of biobased sources or other sustainable sources may be used, as described, for example, in Martin van Duin and Philip Hough, “Green EPDM Compounds”, Kautschuk Gummi Kunststoffe, 01-2, 2018, pages 26-37 and in Martin van Duin et al in Chapter 5, Lightweight and Sustainable Materials for Automotive Applications, CRC Press, 2017. For example, recovered carbon black (rCB) may be used instead of conventional carbon black filler. Recovered carbon black may be obtained, for example, from recycling of scrap tire, roofing membrane scrap, conveyor belt scrap or hose scrap, may be used. Silica-based fillers obtained from rice husk ash may be used to replace conventional silica fillers. Instead of fossil-based mineral processing oils sustainable oils from recycled oils, for example from automotive motor oil recycling, may be used as processing oils. Plant-based oils may be used as processing oils also, for example corn oil, coconut oil, linseed oil, rapeseed oil, soybean oil or vegetable oil.

[0054] The rubber compounds are curable and can be cured to provided vulcanized rubber compounds or “vulcanizates”. Curing agents as known in the art may be used. Suitable curing (vulcanizing) agents include but are not limited to sulfur, sulfur chloride, sulfur dichloride, 4,4'-dithiodimorpholine, morpholine disulfide; alkylphenol disulfide, tetramethylthiuram disulfide (TMTD), tertaethylthiuram disulfide (TETD), selenium dimethyldithiocarbamate, and organic peroxides. Organic peroxides include but are not limited to dicumyl peroxide (DCP), 2,5-di(t-butylperoxy)-2,5-dimethyl-hexane (DTBPH), di(t- butylperoxyisopropyl)benzene (DTBPIB), 2,5-di(benzoylperoxy)-2,5-dimethylhexane, 2,5- (t-butylperoxy)-2,5-dimethyl-3-hexyne (DTBPHY), di-t-butyl-peroxide and di-t- butylperoxide-3,3,5-trimethylcyclohexane (DTBTCH) or mixtures of these peroxides. Sulfur or a sulfur-containing curing agent is preferably used in an amount of 0.1 to 10 phr. Organic peroxide-based curing agents may be used in an amount from 0.1 to 15 phr, preferably from 0.5 to 5 phr. Sulfur may be used in combination with one or more vulcanization accelerators and activators. Examples of vulcanization accelerators include, but are not limited to, N- cyclohexyl-2-benzothiazole-sufenamide, N-oxydiethylene-2-benzothiazole-sulfen-amide,

[0055] N,N-diisopropyl-2-benzothiazole-sulfen-amide, 2-mercaptobenzothiazole, 2-(2,4- dinitrophenyl)mercaptobenzothiazole, 2-(2,6-diethyl-4-morpholinothio)benzothiazole, dibenzothiazyl-disulfide, diphenylguanidine, triphenylguanidine, di-o-tolylguanidine, o-tolyl- bi-guanide, diphenylguanidine-phthalate, an acetaldehyde-aniline reaction product, a butylaldehyde-aniline condensate, hexamethylenetetramine, acetaldehyde ammonia, 2- mercaptoimidazoline, thiocarbaniride, diethylthiourea, dibutylthiourea, trimethylthiourea, di- o-tolylthiourea, tetramethylthiuram monosulfide, TMTD, TETD, terabutylthiuram disulfide, dipentamethylenethiuram tetrasulfide, zinc dimethyldithiocarbamate, zinc diethylthiocarbamate, zinc di-n-butylthiocarbamate, zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate, selenium dimethyldithiocarbamate, tellurium diethyldithiocarbamate, zinc dibutylxanthate and ethylenethiourea. The vulcanization additives may typically be used in an amount of from

[0056] O.1 to 10 parts, preferably from 0.2 to 5 parts or from 0.25 to 2 parts per 100 parts of copolymer. Examples of the vulcanization activators, include but are not limited to, metal oxides, such as magnesium oxide and zinc oxide, stearic acid or its metal salts or combinations thereof. Typically, vulcanization activators are used in amounts from 0.5 to 10 parts per 100 parts of copolymer, preferably in amounts from 0.5 to 5 phr.

[0057] Peroxide-based curing agents may be used in combination with one or more coagents. Examples of suitable coagents include cyanurates, such as triallyl cyanurate and triallylisocyanurate, and (meth)acrylates, such as trimethylolpropane-trimethacrylate, ethyleneglyclol-dimethacrylate, zinc-dimethacrylate and zincdiacrylate. Further examples include divinylbenzene, p-quinonedioxime, m-phenylene dimaleimide, (high vinyl) polybutadiene, and combinations thereof. Typically, from 0.1 up to 5 parts of coagents may be used per 100 parts of copolymer. Peroxide-based curing agents may also be used in combination with sulfur or sulfur-based curing agents. Other curing agents include resol or resol-based curing agents. Fillers

[0058] Typically, fillers may be used in an amount of 20 to 500 phr. Fillers as known in the art may be used including carbon black, silica, calcium carbonate, talcum and clay. The fillers may be surface-treated, for example with silanes. Combinations of two or more of such fillers may be used. Preferably, the filler comprises carbon black and / or silanized silica. Further fillers may include one or more rubber other than the copolymer according to the present disclosure. Preferably, fillers from a sustainable source or obtained from a plant-based material, for example lignin-based materials.

[0059] Other rubber additives (rubber auxiliaries')

[0060] Other rubber additives include those commonly used in the art of rubber compounding. Examples include but are not limited to antioxidants (e.g., hindered phenolics such as commercially available under the trade designation IRGANOX 1010 or IRGANOX 1076 from BASF); phosphites (for example those commercially available under the trade designation IRGAFOS 168), desiccants (e.g. calcium oxide), tackifiers (e.g. polybutenes, terpene resins, aliphatic and aromatic hydrocarbon resins, alkali metal and glycerol stearates, and hydrogenated rosins and the like), bonding agents, heat stabilizers; antiblocking agents; release agents; anti-static agents pigments; colorants; dyes, processing aids (e.g. factice, fatty acids, stearates, poly-or di-ethylene glycols), antioxidants, heat stabilisers (e.g. poly-2, 2, 4-trimethyl-1 ,2-dihydroquinoline or zinc 2- mercaptobenzimidazole), UV stabilisers, anti-ozonants, blowing agents and mould releasing agents, partitioning agents or processing aids like talc or metal salts, such as e.g. zinc stearate, magnesium stearate or calcium stearate and plasticizers (plasticizer lubricating oil, for example those commercially available under the trade designation PLI PROCESS OIL P460), paraffin, liquid paraffin, petroleum asphalt, vaseline, low molecular weight polyisobutylene or polybutylene, liquid EPDM or EPM, coal tar pitch, castor oil, linseed oil, beeswax, atactic polypropylene and cumarone indene resin. Plasticizers may be used typically in amounts from 20 to 250 phr.

[0061] In addition to, or instead of, the above auxiliaries, auxiliaries from a sustainable source may be used to further reduce the C02-footprint of the compound, for example those described in Martin van Duin and Philip Hough, “Green EPDM Compounds”, Kautschuk Gummi Kunststoffe, 01-2, 2018, pages 26-37 and in Martin van Duin et al in Chapter 5, Lightweight and Sustainable Materials for Automotive Applications, CRC Press, 2017. For making articles the rubber compounds are subjected to curing and shaping. Curing (also referred to as “vulcanization”) may take place before, during or after shaping. Articles made by using the ethylene-propylene copolymer according to the present disclosure contain the polymer in cured form, i.e., the polymer is cross-linked either with itself or with other crosslinkable ingredients of the composition used to make the article, for example other curable rubbers. For making articls the rubber compounds may be subjected to one or more curing and shaping processes including, but not limited to, extrusion molding, compression molding, injection molding, foaming, extrusion blow-molding, injection blow-molding, ISBM (Injection Stretched Blow-Molding) and combinations thereof. Typical articles include, but are not limited to, foams, sponges, hoses, belts, seals, engine mounts, roofing material or gaskets. The oil-extended ethylene copolymers of the present disclosure may be used to make layers of layered articles, for example as external or internal layer. Examples of layered materials include hoses, including garden hoses, coolant hoses and hoses for under-the-hood applications and belts including, but are not limited to, conveyor belts, escalator belts and engine belts. The oil-extended ethylene-copolymers of the present disclosure may be used to reduce noise or as vibration-damping materials, for example as engine mounts or in other applications. The ethylene-copolymers according to the present disclosure may be used as sealing materials or for making seals. Seals include solid seals. A solid seal means the material is not foamed and contrary to a foamed material does not contain a cellular or sponge-like structure. Examples of solid seals include seals to make articles airtight, watertight or to reduce vibrations. Examples include O-rings, flanges for openings, for example in washing machines and other devices. The oil-extended ethylene copolymers according to the present disclosure, may also be used for making foamed articles including sponge-like seals or foamed seals.

[0062] The oil-extended copolymers of the present disclosure may be combined with other polymers to make composite materials, or blends or multi-layer articles. Such polymeric resins include, for example, polyethylene, polyethylene copolymers such as ethylene maleic anhydride and the like, polypropylene, polystyrene, polybutadiene, polyvinylchloride, ethylene-vinyl acetate copolymer (EVA), polyesters such as polyethylene terephthalate (PET), polyhydroxyalkanoate (PHA), high impact polystyrene (HIPS), and acrylonitrile butadiene styrene (ABS), polyurethane, elastomers such as 5-vinyl-2-norbornene-EPDM, polysulfide rubber, ethylene propylene rubber (EPM) other than the copolymers according to the present disclosure, poly(ethylene-methyl acrylate), poly(ethylene-acrylate), ethylene propylene diene rubber (EPDM), vinyl silicone rubber (VMQ), fluorosilicone (FVMQ), nitrile rubber (NBR), acrylonitrile-butadiene-styrene (ABS), styrene butadiene rubber (SBR), styrene-butadiene-styrene block copolymers (SBS), styrene-ethylene-butylene-styrene triblock copolymer (SEBS), polybutadiene rubber (BR), styrene-isoprene-styrene block copolymers (SIS), partially hydrogenated acrylonitrile butadiene (HNBR), natural rubber (NR), synthetic polyisoprene rubber (IR), neoprene rubber (CR), polychloropropene, bromobutyl rubber, chlorobutyl rubber, chlorinated poly(ethylene), vinylidene fluoride copolymers (CFM), silicone rubber, vinyl silicone rubber, chlorosulfonated poly(ethylene), fluoroelastomer, elastomeric polyolefins, such as ethylene C3-C12 alpha olefin copolymers, and combinations thereof. In a particular embodiment of the present disclosure the copolymers may be used to make thermoplastic vulcanizates (TPVs). TPV’s comprise finely-divided rubber particles dispersed within a thermoplastic matrix. Advantageously, the rubber particles are cross-linked to promote elasticity. The dispersed rubber phase is referred to also as the discontinuous phase and the thermoplastic phase as continuous phase. TPV’s have the benefit of the elastomeric properties provided by the rubber with the processability of thermoplastics. TPV’s are prepared by dynamic curing. In dynamic curing the rubber is cured using one or more curing agents within a blend with at least one thermoplastic resin under application of shear force, e.g. , while the polymers are undergoing mixing or mastication at some elevated temperature, preferably above the melt temperature of the thermoplastic polymer. Typically, dynamic curing is carried out in an extruder under conditions where the rubber is ground into small particles and is dispersed in the molten thermoplastic and is then subjected to curing and the resulting TPV is extruded from the extruder. Thermoplastic resins typically include polypropylene, polyethylene and combinations thereof as well as combinations with other thermoplastic resins. Examples of TPV’s and method of producing TPV are described, for example, in international patent application WO2019199486A1 , incorporated herein by reference, in particular to pages 11- 15 for selecting thermoplastic polymers and in particular to pages 21-25 for methods of making TPV’s. For suitability in making TPV’s, the oil-extended copolymers are desirably resistant to heat because of the heat generated by the dynamic curing. Mass loss of the oil- extended polymers during dynamic curing is undesired.

[0063] Therefore, in a preferred embodiment of the present disclosure, there is provided a composition for making a thermoplastic vulcanizate, TPV, comprising the ethylenepropylene composition according to the present disclosure, a thermoplastic resin, preferably selected from a polypropylene, a polyethylene or a combination thereof, and a curative.

[0064] In another preferred embodiment of the present disclosure there is provided a process for producing a thermoplastic vulcanizate, TPV, comprising blending the polymer composition according to the present disclosure, a thermoplastic resin, preferably selected from at least one polypropylene, at least one polyethylene or a combination thereof, and a curative, and subjecting the blend to dynamic curing, preferably in an extruder, wherein, preferably, the polymer composition is blended with the thermoplastic resin above the melt temperature of the resin before the curative is added to the blend. Also provided is a thermoplastic vulcanizate, TPV, obtained from this process.

[0065] The present disclosure will be illustrated further by way of examples, without any intention, however, to limit the disclosure to these examples and embodiments represented in these examples.

[0066] Test methods

[0067] Polymer composition:

[0068] Fourier transformation infrared spectroscopy (FT-IR) can be used to determine the composition of the copolymers according to ASTM D 3900 for the C2 / C3 ratio and D 6047 for the diene content on pressed polymer films.

[0069] AS:

[0070] Polymer branching level can be characterized by the parameter AS. AS, expressed in degrees, is the difference between the phase angle 8 at a frequency of 0.1 rad / s and the phase angle 8 at a frequency of 100 rad / s, as determined by Dynamic Mechanical Spectroscopy (DMS) at 125 °C and 10% strain. This quantity A8 is a measure for the amount of long chain branched structures present in the polymer and has been introduced in H.C. Booij, Kautschuk + Gummi Kunststoffe, Vol. 44, No. 2, pages 128-130, which is incorporated herein by reference.

[0071] Molecular weights and molecular weight distribution:

[0072] The molecular weight of the polymer (Mw), the number-averaged molecular weight of the polymer (Mn), the z average molecular weight (Mz) and the molecular weight distribution (MWD, defined as the ratio between Mw and Mn) of the ethylene-copolymers can be determined by gel permeation chromatography (GPC). A Polymer Char GPC from Polymer Characterisation S.A. Valencia, Spain. The Chromatograph can be equipped with an on line viscometer (Polymer charV-400 Viscometer), an online infrared detector (IR% MCT), with 3 AGILENT PL OLEXIS columns (7.5 x 300mm) and a Polymer Char autosampler. Universal calibration of the system is performed with polyethylene (PE) standards. The polymer samples are weighed in a concentration range of 0.3 to 1 .3 mg / ml into the vials of the autosampler. In the autosampler the vials are filled automatically with solvent (1 ,2,4-tri- chlorobenzene, TCB) stabilized with 1g / l di-tert-butyl-paracresol (DBPC). The samples are kept in a high temperature oven at 160°C for 4 hours. After this dissolution time, the samples are automatically filtered by an in-line filter before being injected onto the columns. The chromatograph system is operated at 160°C. The flow rate of the TCB eluent is 1 .OmL / min.

[0073] ENB units per polymer chain:

[0074] The number of ENB units per polymer chain is calculated using the equation:

[0075] ([ENB] x 10 x Polymer Mn) / 120 g / mol, wherein [ENB] is the content of ENB units in the polymer in wt. % (based on the total weight of the polymer which is 100%). 120 g / mol is the molecular weight of ENB. ‘Polymer Mn’ means the number average molecular weight of the polymer in kg / mol.

[0076] Mooney viscosity:

[0077] The Mooney viscosity was measured according to ISO 289. The test conditions (ML 1+4) at 100°C or (ML 1+8) at 150°C as is indicated for the individual measurements.

[0078] Experiments

[0079] Polymers and polymer properties:

[0080] In a first step oil-extended polymers were prepared by mixing various polymers 1 and 2 with 30 phr of various oils (oils 1-4) on a two-roll mill. The properties of the polymers and oils used to make the oil-extended compositions are shown in table 1 and table 2, respectively. The properties of the resulting oil-extended polymer compositions are shown in table 3. Individual experiments are abbreviated as “Ex”. Comparative experiments are abbreviated as “CEx”.

[0081] Table 1 : Properties of the polymers

[0082] The polymer comprised C2 (ethylene), ENB and the remainder was C3 (propylene).

[0083] *MV = Mooney viscosity, ML1 +8,150°C Table 2: Properties of oils

[0084] Table 3: Properties of oil-extended polymer compositions:

[0085] *MU = Mooney units

[0086] Heat Treatment Tests:

[0087] The oil-extended polymers produced in the first step were blended on a two-roll mill at 50°C with 4 phr zinc oxide, 1.5 phr stearic acid, 1.8 phr N-cyclohexyl-2- benzothiazylesulphenamide (RHENOGRAN CBS80) and 1 phr sulfur to produce sheets of curable compound with 2 mm thickness, which were then subjected to curing (30 min at 180°C, ISO 5602). S2-dumbbells were cut from the cured sheets and subjected to heat treatment in dry air according to DIN 53521 at 135°C for 168 hours. The changes in mass and volumes prior and after heat treatment were recorded and are shown in table 4.

[0088] Table 4: heat treatment at 135°C for 168 hours

[0089] Table 4 shows that the oil-extended polymers with oils according to the present disclosure are more heat-resistant (almost no volume and mass change after heat treatment), which shows good compatibility of the high molecular weight polymer and the oil. Oil1 and 2 had a similar flask point and so had oils 3 and 4. However, although the flash points were almost identical, the mass loss after heat treatment differed, which is believed to show a difference in compatibility of the oils with the polymer. The weight loss in g / g of extender oil can be calculated as follows (using the data from CEx1): weight of sample: 1OOphr polymer + 30 phr = 100g polymer + 30 g oil. Weight loss of 1.8% corresponds to weight loss of 130g x 0.018 = 2.34 g. 2.34 g / 30g oil = weight loss of 0.078 g / g extender oil.

[0090] Effect of fillers

[0091] Examples 1 and 2 and Comparative Examples 1 to 6 were repeated except that 50 phr carbon black filler was mixed with the oil-extended polymers before the curative system was added. The properties are shown in table 5 and the results of the heat treatment tests are shown in table 6.

[0092] Table 5: Properties of the filled oil-extended polymer compositions: T able 6: Heat treatment at 135°C for 168 hours

[0093] Table 6 shows that the oil-extended polymers with the oils according to the present disclosure are more heat-resistant (almost no volume and mass change after heat treatment) also in the presence of fillers.

Claims

Claims1. A polymer composition having a Mooney viscosity ML, 1+4, at 100°C of at least 45 Mooney units and comprising at least 90% and up to 100% by weight, based on the weight of the total composition, of an oil-extended ethylene-propylene copolymer comprising from 38% to 70% by weight, of units derived from ethylene, further comprising units derived from propylene and, optionally, at least one further comonomer, wherein the oil-extended copolymer comprises from 20 parts to 150 parts per hundred parts of copolymer of an extender oil having a flash point of greater than 220°C (DIN EN ISO 2592) and a paraffinic content as determined according to ASTM 3238 of greater than 70% wherein, preferably, at least a portion of the extender oil or of the copolymer is obtained from a sustainable carbon source.

2. The polymer composition of claim 1 wherein the oil-extended ethylene-propylene copolymer comprises from 41% to 61% by weight of units derived from ethylene, and wherein the polymer composition comprises the extender oil in an amount of 30 to 100 parts per hundred parts of the copolymer and wherein the extender oil has a flash point of greater than 250°C or preferably at least 260°C.

3. The polymer composition according to claim 1 or claim 2, wherein the extender oil has a paraffinic content of at least 90% or an iodine number of less than 1g l2 / 100 g, or a combination thereof.

4. The polymer composition of any one of the preceding claims, wherein the extender oil has a kinematic viscosity of 50 to 150 mm2 / s at 40°C, as determined according to DIN EN ISO 3104, or a kinematic viscosity at 100°C of from 8 to 35, as determined according to DIN EN ISO 3104, or a combination thereof.

5. The polymer composition of any one of the preceding claims having a weight loss of less than 0.05 g per g of extender oil present in the polymer composition when carrying out a heat treatment test as follows: a) blending the polymer composition on a two-roll mill at 50°C with 4 phr zinc oxide, 1 .5 phr stearic acid, 1.8 phr N-cyclohexyl-2-benzothiazylesulphenamide and 1 phr sulfur to produce a sheet of curable compound having a thickness 2 mm, b) subjecting the sheet to curing for 30 min at 180°C according to ISO 5602 c) cutting S2-dumbbells from the cured sheets and subject them to heat treatment in dry air according to DIN 53521 at 135°C for 168 hours,d) determining the difference in mass of the cured sheet before and after the heat treatment.

6. The polymer composition of any one of the preceding claims wherein (a) at least a portion of the propylene, at least a portion of the ethylene, or both, is obtained from a sustainable carbon source, wherein the sustainable carbon source is either a recycled material or a plant-based material or both, or (b) wherein the polymer composition has a carbon 14 content as determined by ASTM D6866-18 Method B of at least 5%, preferably at least 15%, more preferably at least 25% or even more than 50% based on the total carbon content, of the composition, or a combination of (a) and (b).

7. The polymer composition of any one of the preceding claims wherein the ethylenepropylene copolymer used to make the oil-extended copolymer has a Mooney viscosity ML 1 +8 at 150°C of at least 35 Mooney units, preferably at least 55 Mooney units, and which is greater than the Mooney viscosity of the copolymer composition.

8. The polymer composition of any one of the preceding claims wherein the at least one further comonomer is selected from 5-vinyl-2-norbornene, VNB, 5-ethylidene-2-norbornene or dicyclopentadiene, DCPD, or a combination thereof.

9. The polymer composition of any one of the preceding claims wherein the copolymer comprises from 3% to 12% by weight, based on the total weight of the polymer, of 5- ethylidene-2-norbornene, ENB, as a further comonomer and wherein the ethylenepropylene copolymer used to make the oil-extended copolymer has an ENB content per polymer chain of at least 50, preferably from 70 to 100.

10. The polymer composition of any one of the preceding claims wherein the polymer composition, the extender oil, the ethylene-propylene copolymer or a combination thereof has a carbon 14 content as determined by ASTM D6866-18 Method B of at least 5%, preferably at least 15%, more preferably at least 25%, based on the total carbon content of composition.11 . A process for producing the polymer composition according to any one of the preceding claims comprising:(i) polymerizing the ethylene with the propylene and, optionally, one or more further copolymerizable comonomers, in at least one solvent to produce a reaction mixture comprising the at least one solvent and an ethylene-propylene copolymer comprising from 38% to 70% by weight, based on the total weight of the polymer, of units derived fromethylene, and having a Mooney viscosity ML 1+8, 150°C of at least 35 Mooney units;(ii) adding from 20 parts to 150 parts of extender oil to the reaction mixture and blending it with the copolymer, wherein the extender oil has a flash point of greater than 220°C (DIN EN ISO 2592) and a paraffinic content as determined according to ASTM 3238 of greater than 70% and wherein, preferably, at least a portion of the extender oil is obtained from a sustainable carbon source,(iii) removing the solvent.

12. A process for making a curable polymer composition comprising combining the polymer composition of any one of claims 1 to 10 with at least one curing agent for curing the ethylene-propylene copolymer.

13. An article comprising the reaction product of a curing reaction comprising as reactants the polymer composition of any one of claims 1 to 10 and at least one curing agent for curing the copolymer.

14. A composition for making a thermoplastic vulcanizate, TPV, comprising a polymer composition according to any one of claims 1 to 10, a thermoplastic resin, preferably selected from a polypropylene, a polyethylene or a combination thereof, and a curative.

15. A process for producing a thermoplastic vulcanizate, TPV, comprising blending a polymer composition according to any one of claims 1 to 10, a thermoplastic resin, preferably selected from at least one polypropylene, at least one polyethylene or a combination thereof, and a curative, and subjecting the blend to dynamic curing, preferably in an extruder, wherein, preferably, the polymer composition according to claims 1 to 10 is blended with the thermoplastic resin above the melt temperature of the resin before the curative is added to the blend.

16. A thermoplastic vulcanizate, TPV, obtained from the process of claim 15.

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