Polymer composition with improved multi-axial impact resistance

Abstract

The present invention relates to a polymer composition with improved multi-axial impact resistance comprising a first heterophasic propylene copolymer, a second heterophasic propylene copolymer and a first ethylene based elastomer and a second ethylene based elastomer. The present invention further relates to a process for the preparation of said polymer composition. The present invention further relates to an automotive part comprising such polymer composition.

Description

[0001] Polymer composition with improved multi-axial impact resistance

[0002] The present invention relates to a polymer composition comprising a first heterophasic propylene copolymer, a second heterophasic propylene copolymer and a first ethylene based elastomer and a second ethylene based elastomer. The present invention further relates to a process for the preparation of said polymer composition. The present invention further relates to an automotive part comprising such polymer composition.

[0003] Polymer compositions, especially polymer compositions based on polypropylene are widely used in automotive industry thanks to their excellent mechanical and chemical properties. The polymer composition material used in automotive preferably has excellent multi-axial impact resistance especially for the sake of safety.

[0004] WO2019030139 discloses a composition comprising (A) a propylene-based polymer, (B1 ) a first elastomer of ethylene and oolefin comonomer having 4 to 10 carbon atoms, (B2) a second elastomer of ethylene and oolefin comonomer having 4 to 10 carbon atoms and (C) an inorganic filler, wherein (B1 ) the first elastomer has a density of 0.850 to 0.890 g / cm3 and a melt flow index of 5 to 50 g / 10min measured in accordance with ASTM D1238 using a 2.16 kg weight and at a temperature of 190 °C, wherein (B2) the second elastomer has a density of 0.850 to 0.890 g / cm3 and a melt flow index of 0.55 to 4 g / 10min measured in accordance with ASTM D1238 using a 2.16 kg weight and at a temperature of 190 °C, wherein the total amount of (B1 ) the first elastomer and (B2) the second elastomer is 2 to 30 wt% based on the total composition, wherein the amount of (C) the inorganic filler is 0.1 to 30 wt% based on the total composition.

[0005] WO2019030139 further discloses that such composition has improved Izod impact resistance (Uni-axial impact).

[0006] The inventor of the present invention found that the result of uni-axial impact resistance can not represent the result of multi-axial impact resistance and there is still a need for the composition with improved multi-axial impact resistance. This purpose is achieved by a polymer composition comprising a first heterophasic propylene copolymer, a second heterophais propylene copolymer, a first ethylene based elastomer and a second ethylene based elastomer, optional inorganic filler and optional additives wherein the melt flow index (MFI) of the first heterophasic propylene copolymer is in the range 70 to 220 g / 10min as determined according to ISO1133-1 :2011 at 230 °C with a 2.16 kg load, wherein the xylene-soluble portion of the first heterophasic propylene copolymer is in the range from 11 to 27 wt% based on the total amount of the first heterophasic propylene copolymer as determined according to ISO16152:2005, wherein the density of the first ethylene based elastomer is in the range from 0.853 to 0.865 g / cm3as measured according to ASTM D792-13, wherein the MFI of the first ethylene based elastomer is in the range from 0.2 to 4.0 g / 10min as measured according to ASTM D1238-13 with a 2.16 kg load at 190°C, wherein the density of the second ethylene based elastomer is in the range from 0.866 to 0.875 g / cm3as measured according to ASTM D792-13, wherein the MFI of the second ethylene based elastomer is in the range from 20 to 50 g / 10min as measured according to ASTM D1238-13 with a 2.16 kg load at 190°C. wherein the total amount of the first ethylene based elastomer and the second ethylene based elastomer is in the range from 20 to 30 wt%, preferably from 21 to 25 wt% basing on the total amount of the polymer composition.

[0007] The inventor surprisingly found the a synergistic effect exists in the combination of the components of the polymer composition, especially between the first heterophasic propylene copolymer, the first ethylene based elastomer and the second ethylene based elastomer.

[0008] Heterophasic propylene copolymer

[0009] A heterophasic propylene copolymer typically has a two-phase structure, comprises a propylene- based semi-crystalline polymer as matrix and a dispersed elastomer phase, usually an ethylene- a-olefin rubber. Heterophasic propylene copolymers are usually prepared in one polymerization process. The first heterophasic propylene copolymer (a)

[0010] The first heterophasic propylene copolymer (a) preferably comprises a first propylene polymer (a1) as matrix and a first ethylene-a-olefin copolymer (a2) as dispersed phase.

[0011] The amount of the first propylene polymer (a1) is preferably in the range from 80 to 92 wt%, preferably from 85 to 90 wt% based on the total amount of the first heterophasic propylene copolymer (a).

[0012] The first propylene polymer (a1) in the first heterophasic propylene copolymer (a) can be a propylene homopolymer or / and a propylene-a-olefin copolymer wherein the a-olefin has 2 or 4 to 20 carbon atoms, for example the propylene-a-olefin can be a propylene-ethylene copolymer or a propylene-butene copolymer. Preferably the first propylene polymer (a1) in the first heterophasic propylene copolymer (a) is a propylene homopolymer.

[0013] The melt flow index (MFI) of the first propylene polymer (a1) in the first heterophasic propylene copolymer (a) is preferably in the range from 200 to 500 g / 10min, preferably from 210 to 370 g / 10min, more preferably from 220 to 250 g / 10min as determined according to ISO1133-1 :2011 at 230 °C with 2.16 kg load.

[0014] The amount of the first ethylene-a-olefin copolymer (a2) is preferably in the range from 8 to 20 wt%, preferably from 10 to 15 wt% based on the total amount of the first heterophasic propylene copolymer (a).

[0015] In the first heterophasic propylene copolymer (a), the amount of the moiety derived from ethylene is preferably in the range from 40 to 53 wt% based on the total amount of the first ethylene-a- olefin copolymer (a2).

[0016] The moiety of a-olefin in the first ethylene-a-olefin copolymer (a2) in the first heterophasic propylene copolymer (a) is preferably derived from at least one a-olefin having 3 to 20 carbon atoms, for example the first ethylene-a-olefin copolymer (a2) can be an ethylene-propylene copolymer, for example the first ethylene-a-olefin copolymer (a2) can be an ethylene-butene copolymer, for example the first ethylene-a-olefin copolymer (a2) can be an ethylene-hexene copolymer, for example the first ethylene-a-olefin copolymer (a2) can be an ethylene-octene copolymer, for example the first ethylene-a-olefin copolymer (a2) can be an ethylene-propylene- butene copolymer, for example the first ethylene-a-olefin copolymer (a2) can be an ethylene- propylene-hexene copolymer. Preferably the first ethylene-a-olefin copolymer (a2) in the first heterophasic propylene copolymer (a) is an ethylene-propylene copolymer

[0017] The MFI of the first heterophasic propylene copolymer (a) is in the range from 70 to 220 g / 10min, preferably from 72 to 150 g / 10min, more preferably from 75 to 100 g / 10min, as determined according to ISO1133-1 :2011 at 230 °C with a 2.16 kg load.

[0018] The first heterophasic propylene copolymer (a) can be divided into a first xylene-soluble portion (First CXS) and a first xylene-insoluble portion (First CXI). The amount of the xylene-soluble portion of the first heterophasic propylene copolymer (a) is in the range from 11 to 27 wt%, preferably from 11 to 16 wt% based on the total amount of the first heterophasic propylene copolymer (a) as determined according to ISO16152:2005 at25°C. The amount of the first xylene- insoluble portion based on the total amount of the first heterophasic propylene copolymer is calculated by the following equation:

[0019] First CXI = 100 wt% - First CXS

[0020] The ratio between the intrinsic viscosity of the xylene-soluble portion of the first heterophasic propylene copolymer (a) IVFirstcxs and the intrinsic viscosity of the xylene-insoluble part of the first heterophasic propylene copolymer (a) IVFjrst cxi is preferably in the range from 3.6 to 7.2, more preferably from 4.2 to 5.1 , wherein IVFjrst cxs and IVnrst cxi are measured according to ISO1628- 1 :2009 and IS01628-3:2010 respectively.

[0021] The intrinsic viscosity of the first xylene-insoluble part (First CXI) of the first heterophasic propylene copolymer (a) IVFirstcxi is preferably in the range from 0.90 to 1.26 dl / g, more preferably from 0.95 to 1.25 dl / g, more preferably from 1.0 to 1.15 dl / g, as measured according to ISO1628- 3:2010.

[0022] The intrinsic viscosity of the first xylene-soluble part (First CXS) of the first heterophasic propylene copolymer (a) IVFirstcxs is preferably in the range from 4.5 to 6.5 dl / g, more preferably from 4.8 to 6.5 dl / g, even more preferably from 4.8 to 6.0 dl / g as measured according to IS01628-1 :2009.

[0023] The first heterophasic propylene copolymer (a) is preferably a non-visbroken heterophasic propylene copolymer. The term non-visbroken is known in the art, yet for the avoidance of doubt it means that the materials was not treated such as to modify the molecular weight and / or the molecular weight distribution of the polymer directly after polymerisation. In other words, non- visbroken polymers are not treated with peroxides, radiation, or any other initiating source for chain breaking reactions to occur. An advantage of non-visbroken polypropylenes over vis-broken polypropylenes is that the former generally suffer less from the release of low molecular weight materials, such materials inherently being produced upon visbreaking and is not desired for automitve application. For the avoidance of doubt, the term reactor grade indicates that the copolymer is non-visbroken. The first heterophasic propylene copolymer (a) is preferably a reactor grade heterophasic propylene copolymer.

[0024] The process to produce the first heterophasic propylene copolymer (a) is known in the art. Preferably the first heterophasic propylene copolymer (a) is produced in a sequential polymerization process comprising at least two reactors, more preferably the polypropylene of the present invention is produced in a sequential polymerization process comprising at least three reactors.

[0025] The catalyst used in the preparation of the first heterophasic propylene copolymer (a) is also know in the art, for example Ziegler-Natta catalyst, metallocene catalyst. Preferably the catalyst used to produce the first heterophasic propylene copolymer is free of phthalate, for example the catalyst comprises compounds of a transition metal of Group 4 to 6 of IIIPAC, a Group 2 metal compound and an internal donor wherein said internal donor is a compound selected from optionally substituted malonates, maleates, succinates, glutarates, cyclohexene-1 ,2-dicarboxylates, benzoates, citraconate and derivatives and / or mixtures thereof.

[0026] For example the catalyst used in the preparation of the first heterophasic propylene copolymer (a) is a Ziegler-Natta catalyst comprising a procatalyst, at least one external donor, a co-catalyst and an optional internal donor wherein the external electron donor is chosen from the group consisting of a compound having a structure according to Formula III (R90)2N-Si(OR91)3 , a compound having a structure according to Formula IV: (R92)Si(OR93)3 and mixtures thereof, wherein each of R90, R91, R92and R93groups are each independently a linear, branched or cyclic, substituted or unsubstituted alkyl having between 1 and 10 carbon atoms, preferably a linear unsubstituted alkyl having between 1 and 8 carbon atoms, preferably ethyl, methyl or n-propyl.

[0027] In one embodiment, R90and R91are each ethyl (compound of Formula III is diethylaminotriethoxysilane, DEATES). In another embodiment, R92is n-propyl and R93are each ethyl (compound of Formula IV is n-propyl triethoxysilane, nPTES) or in another embodiment R92is n-propyl and R93are each methyl (compound of Formula IV is n-propyl trimethoxysilane, nPTMS). Preferably, the heterophasic propylene copolymer of the invention is prepared by a catalyst system comprising a Ziegler-Natta catalyst and at least one external electron donor chosen from the group of a compound having a structure according to Formula III (R90)2N-Si(OR91)3, a compound having a structure according to Formula IV: (R92)Si(OR93)3 and mixtures thereof.

[0028] A "co-catalyst" is a term well-known in the art in the field of Ziegler-Natta catalysts and is recognized to be a substance capable of converting the procatalyst to an active polymerization catalyst. Generally, the co-catalyst is an organometallic compound containing a metal from group 1 , 2, 12 or 13 of the Periodic System of the Elements (Handbook of Chemistry and Physics, 70th Edition, CRC Press, 1989- 1990). The co-catalyst may include any compounds known in the art to be used as “co-catalysts”, such as hydrides, alkyls, or aryls of aluminum, lithium, zinc, tin, cadmium, beryllium, magnesium, and combinations thereof. The co-catalyst may be a hydrocarbyl aluminum co-catalyst, such as triisobutylaluminum, trihexylaluminum, di-isobutylaluminum hydride, dihexylaluminum hydride, isobutylaluminum dihydride, hexylaluminum dihydride, diisobutylhexylaluminum, isobutyl dihexylaluminum, trimethylaluminum, triethylaluminum, tripropylaluminum, triisopropylaluminum, tri-n-butylaluminum, trioctylaluminum, tridecylaluminum, tridodecylaluminum, tribenzylaluminum, triphenylaluminum, trinaphthylaluminum, and tritolylaluminum. In an embodiment, the cocatalyst is selected from triethylaluminum, triisobutylaluminum, trihexylaluminum, di-isobutylaluminum hydride and dihexylaluminum hydride. More preferably, trimethylaluminium, triethylaluminium, triisobutylaluminium, and / or trioctylaluminium. Most preferably, triethylaluminium (abbreviated as TEAL). The co-catalyst can also be a hydrocarbyl aluminum compound such as tetraethyl-dialuminoxane, methylaluminoxane, isobutylaluminoxane, tetraisobutyl-dialuminoxane, diethylaluminumethoxide, diisobutylaluminum chloride, methylaluminum dichloride, diethylaluminum chloride, ethylaluminum dichloride and dimethylaluminum chloride, preferably TEAL.

[0029] For example, the procatalyst may be prepared by a process comprising the steps of providing a magnesium-based support, contacting said magnesium-based support with a Ziegler-Natta type catalytic species, an internal donor, and an activator, to yield the procatalyst. For example, the Examples of US 5,093,415 of Dow discloses an improved process to prepare a procatalyst. Preferably, the procatalyst is a chemical compound comprising titanium.

[0030] In the context of the present invention, the molar ratio between Si and Ti element in the catalyst system is preferably in the range from 0.1 to 40, preferably from 0.1 to 20, even more preferably from 1 to 20 and most preferably from 2 to 10. Preferably the molar ratio between Al and Ti element in the catalyst system is in the range from 5 to 500, preferably from 15 to 200, more preferably from 30 to 160, most preferably from 50 to 140.

[0031] In one embodiment, the molar ratio between Si and Ti element is the molar ratio between the external donor and the procatalyst.

[0032] In one embodiment, the molar ratio between Al and Ti element is the molar ratio between the cocatalyst and the procatalyst.

[0033] The second heterophasic propylene copolymer (b)

[0034] The second heterophasic propylene copolymer (b) preferably comprises a second propylene polymer (b1) as matrix and a second ethylene-a-olefin copolymer (b2) as dispersed phase.

[0035] The amount of the second propylene polymer (b1) is preferably in the range from 70 to 92 wt%, preferably from 72 to 90 wt% based on the total amount of the second heterophasic propylene copolymer (a).

[0036] Preferably the MFI of the second heterophasic propylene copolymer (b) is in the range from 10 to 150 g / 10min, more preferably from 12 to 120 g / 10min as determined according to ISO1133- 1 :2011 at 230 °C with a 2.16 kg load.

[0037] The second heterophasic propylene copolymer (b) can be divided into a second xylene-soluble portion (Second CXS) and a second xylene-insoluble portion (Second CXI). The amount of the xylene-soluble portion of the second heterophasic propylene copolymer (b) is preferably in the range from 11 to 27 wt%, preferably from 11 to 16 wt% based on the total amount of the second heterophasic propylene copolymer (b) as determined according to ISO16152:2005 at 25°C.

[0038] The amount of the Second CXI may be calculated in the similar manner as the First CXI.

[0039] The intrinsic viscosity of the second xylene-insoluble part (Second CXI) of the second heterophasic propylene copolymer (a) IVSecondcxi is preferably in the range from 1.15 to 1.60 dl / g, more preferably from 1.18 to 1.40 dl / g, as measured according to IS01628-3:2010. The intrinsic viscosity of the second xylene-soluble part (Second CXS) of the second heterophasic propylene copolymer (a) IVsecond cxs is preferably in the range from 2.0 to 4.80 dl / g, more preferably from 2.15 to 4.75 dl / g as measured according to ISO1628-1 :2009.

[0040] The second heterophasic propylene copolymer may be produced in the same process as the first heterophasic propylene copolymer.

[0041] The first ethylene based elastomer

[0042] The first ethylene based elastomer is preferably an ethylene-a-olefin copolymer wherein the a- olefin has 3 to 20 carbon atoms, for example the ethylene-a-olefin copolymer is an ethylenepropylene copolymer, for example the ethylene-a-olefin copolymer is an ethylene-butene copolymer, for example the ethylene-a-olefin copolymer is an ethylene-hexene copolymer, for example the ethylene-a-olefin copolymer is an ethylene-octene copolymer or a combination thereof.

[0043] Preferably the first ethylene based elastomer is an ethylene-butene copolymer or / and an ethylene-octene copolymer. More preferably the first ethylene based elastomer is an ethylene- octene copolymer.

[0044] Preferably the amount of moiety derived from ethylene in the first ethylene based elastomer is in the range from 42 to 60 wt%, preferably from 43 to 55 wt%, more preferably from 44 to 50 wt%, based on the total amount of the first ethylene based elastomer.

[0045] The density of the first ethylene based elastomer according to the present invention is in the range from 0.853 to 0.865 g / cm3, preferably from 0.856 to 0.863 g / cm3, as measured according to ASTM D792-13.

[0046] The MFI of the first ethylene based elastomer is in the range from 0.2 to 4.0 g / 10min, preferably from 0.3 to 2.5 g / 10min, more preferably from 0.4 to 1.8 g / 10min as measured according to ASTM D1238-13 with a 2.16 kg load at 190°C.

[0047] The first ethylene based elastomer may be prepared using methods known in the art, for example by using a single site catalyst, i.e., a catalyst the transition metal components of which is an organometallic compound and at least one ligand of which has a cyclopentadienyl anion structure through which such ligand bondingly coordinates to the transition metal cation. This type of catalyst is also known as "metallocene" catalyst. Metallocene catalysts are for example described in U.S. Patent Nos. 5,017,714 and 5,324,820. The ethylene based elastomer may also be prepared using traditional types of heterogeneous multi-sited Ziegler-Natta catalysts.

[0048] The second ethylene based elastomer

[0049] The second ethylene based elastomer is preferably an ethylene-a-olefin copolymer wherein the a-olefin has 3 to 20 carbon atoms, for example the ethylene-a-olefin copolymer is an ethylenepropylene copolymer, for example the ethylene-a-olefin copolymer is an ethylene-butene copolymer, for example the ethylene-a-olefin copolymer is an ethylene-hexene copolymer, for example the ethylene-a-olefin copolymer is an ethylene-octene copolymer or a combination thereof.

[0050] Preferably the second ethylene based elastomer is an ethylene-butene copolymer or / and an ethylene-octene copolymer. More preferably the second ethylene based elastomer is an ethylene- octene copolymer.

[0051] Preferably the amount of moiety derived from ethylene in the second ethylene based elastomer is in the range from 35 to 50 wt%, preferably from 37 to 45 wt%, more preferably from 38 to 43 wt%, based on the total amount of the second ethylene based elastomer.

[0052] The density of the second ethylene based elastomer according to the present invention is in the range from 0.866 to 0.875 g / cm3, preferably from 0.868 to 0.873 g / cm3, as measured according to ASTM D792-13.

[0053] The MFI of the second ethylene based elastomer is in the range from 20 to 50 g / 10min, preferably from 25 to 38 g / 10min, more preferably from 28 to 33 g / 10min as measured according to ASTM D1238-13 with a 2.16 kg load at 190°C.

[0054] The second ethylene based elastomer may be produced in the same process as the first ethylene based elastomer.

[0055] Inorganic filler The polymer composition according to the present invention may further comprise an inorganic filler.

[0056] Suitable examples of inorganic fillers include but are not limited to talc, calcium carbonate, wollastonite, barium sulfate, kaolin, glass flakes, laminar silicates (bentonite, montmorillonite, smectite) and mica.

[0057] For example, the inorganic filler is chosen from the group of talc, calcium carbonate, wollastonite, mica and mixtures thereof.

[0058] More preferably, the inorganic filler is talc. The mean particle size of talc (D50) of talc is preferably in the range from 0.1 to 10.2 micron, preferably from 0.3 to 8.1 micron, more preferably from 0.5 to 5.2 micron, even more preferably from 0.6 to 2.5 micron according to sedimentation analysis, Stockes’ law (ISO 13317-3:2001).

[0059] Optional additives

[0060] The polymer composition according to the present invention may further contain additives, for instance nucleating agents and clarifiers, stabilizers, release agents, plasticizers, anti-oxidants, lubricants, antistatics, cross linking agents, scratch resistance agents, high performance fillers, pigments and / or colorants, flame retardants, blowing agents, acid scavengers, recycling additives, anti-microbials, anti-fogging additives, slip additives, anti-blocking additives, polymer processing aids and the like. Such additives are well known in the art. The amount of the additives is preferably to be at most 5.0 wt%, preferably at most 4.5 wt%, preferably at most 4 wt%, more preferably at most 3.8 wt% based on the total amount of the polymer composition. The reason for the preference of the low amount of additives is that at this amount, additives do not have negative influence on the desired properties of the polymer composition according to the present invention.

[0061] Polymer composition

[0062] The MFI of the polymer composition is preferably in the range from 23 to 38 g / 10min.

[0063] Preferably the amount of the first heterophasic propylene copolymer is in the range from 12 to 55 wt%, more preferably from 13 to 43 wt% basing on the total amount of the polymer composition. Preferably the amount of the second heterophasic propylene copolymer is in the range from 18 to 40 wt%, more preferably from 20 to 27 wt% basing on the total amount of the polymer composition.

[0064] Preferably the amount of the first ethylene based elastomer is in the range from 9 to 15 wt%, more preferably from 10 to 13 wt% basing on the total amount of the polymer composition.

[0065] Preferably the amount of the second ethylene based elastomer is in the range from 10 to 15 wt%, more preferably from 10 to 13 wt% basing on the total amount of the polymer composition.

[0066] The amount of the total amount of the first ethylene based elastomer and the second ethylene based elastomer is in the range from 20 to 30 wt%, preferably from 21 to 25 wt% basing on the total amount of the polymer composition.

[0067] Preferably the ratio between the amount of the first ethylene based elastomer and the amount of the second ethylene based elastomer is in the range from 1.5:1 to 1 :1.5, more preferably from 1.2:1 to 1 :1.2.

[0068] Preferably the amount of the inorganic filler is in the range from 10 to 25 wt% basing on the total amount of the polymer composition.

[0069] Preferably the total amount of the first heterophasic propylene copolymer, the second heterophasic propylene copolymer, the first ethylene based elastomer, the second ethylene based elastomer, and the inorganic filler is at least 90 wt%, preferably at least 95 wt%, more preferably at least 98 wt%, basing on the total amount of the polymer composition.

[0070] Preferably the total amount of the first heterophasic propylene copolymer, the second heterophasic propylene copolymer, the first ethylene based elastomer, the second ethylene based elastomer, the inorganic filler and optional additives is 100 wt% basing on the total amount of the polymer composition.

[0071] Preferably the polymer composition has a YD or YS break type of at least 35 % in VEM measurement according to ISO 6603-A2.

[0072] Preferably the polymer composition has a Ductility type of breaking of at least 75 % in MAI measurement according to ASTM D3763.

[0073] Preferably the polymer composition has a tensile modulus of at least 1300 MPa as measured according to ISO 527 / 1A The polymer composition according to the invention can for example be prepared in a compounding process.

[0074] The present invention further relates to an article comprising the polymer composition according the invention. Preferably the article is an automotive exterior part. Preferably the amount of the polymer composition is at least 90 wt%, preferably at least 92 wt%, more preferably at least 95 wt%, even more preferably at least 98 wt% of the total amount of the article.

[0075] The article can for example be prepared in an injection molding process. Examples

[0076] Materials:

[0077] FPC 100 is commercially available from SABIC under the name of SABIC PP FPC100. It has a MFI of 100 g / 10min as measured according to ISO 1133

[0078] The production processes of Polymer B and D are shown as below in Table 1 Table 1 : Process conditions of Heterophasic propylene copolymer (HECO) In Table 1 , R1 refers to the first reactor, R2 refers to the second reactor, Al / Ti is the molar ratio of the co-catalyst to the procatalyst, Si / Ti is the molar ratio of the external donor to the procatalyst, H2 / C3 is the molar ratio of hydrogen to propylene, C2 / C3 is the molar ratio of ethylene to propylene, split is the amount of substance produced in R1 or R2 based on the amount of the total Polymer B or D respectively. The properties of Polymer B, and D provided in Table 2.

[0079] Table 2: Properties of Heterophasic propylene copolymer (HECO)

[0080] Details Polymer B Polymer D

[0081] MFR (g / 10min) 14 77

[0082] PP homopolymer matrix MFI (g / 10min) 85 230

[0083] PP homopolymer matrix (wt. %) 74 86

[0084] CXS fraction (wt. %) 22

[0085] IV CXS (dl / g) 4.59 5.35

[0086] IV CXI (dlZ g) 1.29 1.04

[0087] IV CXS / IV CXI 3.56 5.14

[0088] FPC 100 is a heterophasic propylene copolymer commercially available from SABIC. It has a melt flow index of 100 g / 10min as measured according to ISO 1133-1 :2011 (2.16kg, 230°C), CXS of 16.0 wt%, IV of CXS 2.3 dl / g and IV of CXI 1 .2 dl / g.

[0089] TI2600C is a heterophasic propylene copolymer commercially available from Braskem. It has a melt flow index of 66 g / 10min as measured according to ISO 1133 (2.16kg, 230°C), CXS of 10.1 wt%, IV of CXS 6.70 dl / g and IV of CXI 1 .30 dl / g.

[0090] Engage 8407 is an ethylene octene copolymer commercially available from Dow, it has an MFI of 30 g / 10min as measured according to ASTM D1238-13 (190°C, 2.16kg). It has a density of 0.870 g / cm3 as measured according to ASTM D792-13.

[0091] Engage 8200 is an ethylene octene copolymer commercially available from Dow, it has an MFI of 5 g / 10min as measured according to ASTM D1238-13 (190°C, 2.16kg). It has a density of 0.870 g / cm3 as measured according to ASTM D792-13.

[0092] Tafmer DF605 is an ethylene butene copolymer commercially available from Mitsui Chemicals, it has an MFI of 0.5 g / 10min as measured according to ASTM D1238-13 (190°C, 2.16kg). It has a density of 0.861 g / cm3 as measured according to ASTM D792-13. Fortify C1055D is an ethylene octene copolymer commercially available from SABIC, it has an MFI of 1 g / 10min as measured according to ASTM D1238-13 (190°C, 2.16kg). It has a density of 0.857 g / cm3 as measured according to ASTM D792-13.

[0093] HAR talc is a high aspect ratio talc commercially available from Imerys Talc. The mean particle size of talc (D50) of Luzenac HAR T84 is 2 micron as measured according to sedimentation analysis, Stockes’ law (ISO 13317-3:2001).

[0094] Additive package 1 consists of 40 wt% color masterbatch, 20 wt% acid scavenger, 12 wt% slipping agent, 16 wt% antioxidant, 4 wt% nucleating agent and 8 wt% UV stabilizer basing on the total amount of Additive package 1 .

[0095] Additive package 2 consists of 75 wt% color masterbatch, 9 wt% slipping agent, 9 wt% antioxidant and 7 wt% UV stabilizer basing on the total amount of Additive package 2.

[0096] Pellets of Examples were prepared by compounding the components in Table 3 in a KraussMaffei Berstorff ZE40A_UTX 43D twin-screw extruder with the following setting: 400 rpm screw speed, 150kg / h throught put, 38% torque, 235 °C as temperature and 13 bar as head pressure.

[0097] Measurement

[0098] MFI of the composition and / or polypropylene is measured according to ISO 1133-1 :2011 (2.16kg, 230°C);

[0099] Weight percentage of the xylene-soluble part (CXS) and weight percentage of the xylene- insoluble part (CXI)

[0100] Weight percentage of the xylene-soluble part (CXS) of the heterophasic propylene copolymers was determined according to 15016152:2005 at 25°C. Weight percentage of xylene-insoluble part (CXI) of the heterophasic propylene copolymers was calculated using the following equation:

[0101] CXI = 100 wt% - CXS

[0102] Both xylene-soluble and xylene-insoluble parts (CXS and CXI) obtained in this test were used in the intrinsic viscosity (IV) test. Intrinsic viscosity (IV)

[0103] Intrinsic viscosity (IV) of CXS and CXI was determined according to 1801628-1:2009 and 1801628-3:2010 respectively in decalin at 135 °C. Charpy at 23°C and -30°C was measured according to ISO179 / 1eA;

[0104] Tensile modulus was measured according to ISO 527 / 1 A;

[0105] MAI (multi axial impact) was carried out according to ASTM D3763;

[0106] VEM was carried out according to ISO 6603-A2. Result

[0107] Table 3 Formulations and testing result of Examples

[0108] VEM break type rating:

[0109] YD : Yielding followed by deep drawing (Ductile) - most preferred

[0110] YS : Yielding followed by stable cracking (Semi-ductile) - preferred YU : Yielding followed by unstable cracking (Semi-brittle) - least preferred

[0111] NY : No yielding (Brittle) - not preferred

[0112] Clearly the comparison between lEs and CEs show that the lEs according to the invention have improved multi-axial impact resistance according to the MAI at -30°C and VEM at -40°C.

Claims

Claim1. A polymer composition comprising a first heterophasic propylene copolymer, a second heterophasic propylene copolymer, a first ethylene based elastomer, a second ethylene based elastomer, an inorganic filler and optional additives wherein the melt flow index (MFI) of the first heterophasic propylene copolymer is in the range 70 to 220 g / 10min as determined according to ISO1133-1:2011 at 230 °C with a 2.16 kg load, wherein the xylene-soluble portion of the first heterophasic propylene copolymer is in the range from 11 to 27 wt% based on the total amount of the first heterophasic propylene copolymer as determined according to ISO16152:2005, wherein the density of the first ethylene based elastomer is in the range from 0.853 to 0.865 g / cm3as measured according to ASTM D792-13, wherein the MFI of the first ethylene based elastomer is in the range from 0.2 to 4.0 g / 10min as measured according to ASTM D1238-13 with a 2.16 kg load at 190°C, wherein the density of the second ethylene based elastomer is in the range from 0.866 to 0.875 g / cm3as measured according to ASTM D792-13, wherein the MFI of the second ethylene based elastomer is in the range from 20 to 50 g / IOmin as measured according to ASTM D1238-13 with a 2.16 kg load at 190°C, wherein the amount of the first ethylene based elastomer is in the range from 9 to 15 wt%, the amount of the second ethylene based elastomer is in the range from 10 to 15 wt%, and the total amount of the first ethylene based elastomer and the second ethylene based elastomer is in the range from 20 to 30 wt%, preferably from 21 to 25 wt%, basing on the total amount of the polymer composition, wherein the total amount of the first heterophasic propylene copolymer, the second heterophasic propylene copolymer, the first ethylene based elastomer, the second ethylene based elastomer, and the inorganic filler is at least 90 wt% of the polymer composition.

2. The polymer composition according to claim 1 wherein the MFI of the polymer composition is in the range from 23 to 38 g / 10min as determined according to ISO1133-1 :2011 at 230 °C with a 2.16 kg load.

3. The polymer composition according to claim 1 or 2 wherein the intrinsic viscosity of the first xylene-insoluble part of the first heterophasic propylene copolymer is in the range from 0.90 to1.26 dl / g, preferably from 0.95 to 1.25 dl / g, more preferably from 1.0 to 1.15 dl / g, as measured according to ISO1628-3:2010.

4. The polymer composition according to any one of the previous claims wherein the MFI of the second heterophasic propylene copolymer is in the range from 10 to 150 g / 10min, preferably from 12 to 120 g / 10min as determined according to ISO1133-1 :2011 at 230 °C with a 2.16 kg load.

5. The polymer composition according to any one of the previous claims wherein the amount of the xylene-soluble portion of the second heterophasic propylene copolymer is in the range from 11 to 27 wt%, preferably from 11 to 16 wt% based on the total amount of the second heterophasic propylene copolymer as determined according to 18016152:2005 at 25°C.

6. The polymer composition according to any one of the previous claims wherein the first ethylene based elastomer is an ethylene-butene copolymer or / and an ethylene-octene copolymer, preferably the first ethylene based elastomer is an ethylene-octene copolymer.

7. The polymer composition according to any one of the previous claims wherein the amount of moiety derived from ethylene in the first ethylene based elastomer is in the range from 42 to 60 wt%, preferably from 43 to 55 wt%, more preferably from 44 to 50 wt%, based on the total amount of the first ethylene based elastomer.

8. The polymer composition according to any one of the previous claims wherein the second ethylene based elastomer is an ethylene-butene copolymer or / and an ethylene-octene copolymer, preferably the second ethylene based elastomer is an ethylene-octene copolymer.

9. The polymer composition according to any one of the previous claims wherein the amount of the first heterophasic propylene copolymer is in the range from 12 to 55 wt%, preferably from 13 to 43 wt% basing on the total amount of the polymer composition.

10. The polymer composition according to any one of the previous claims wherein the amount of the first ethylene based elastomer is in the range from 10 to 13 wt% basing on the total amount of the polymer composition.

11. The polymer composition according to any one of the previous claims wherein the amount of the second ethylene based elastomer is in the range from 10 to 13 wt% basing on the total amount of the polymer composition.

12. The polymer composition according to any one of the previous claims, wherein the amount of the inorganic filler is in the range from 10 to 25 wt%.

13. The polymer composition according to any one of the previous claims wherein the total amount of the first heterophasic propylene copolymer, the second heterophasic propylene copolymer, the first ethylene based elastomer, the second ethylene based elastomer, the optional inorganic filler and additives is 100 wt% basing on the total amount of the polymer composition14. The polymer composition according to any one of the previous claims wherein the polymer composition has a YD or YS break type of at least 35 % in VEM measurement according to ISO 6603- A2.

15. An article comprising the polymer composition according to any one of the previous claims wherein the article is an automotive exterior part.

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