Heterophasic polypropylene composition with low shrinkage

Abstract

The present invention relates to a polypropylene composition comprising a heterophasic propylene copolymer wherein the heterophasic propylene copolymer consists of: a propylene homopolymer matrix in an amount of 71 to 92 wt%, preferably 78 to 89 wt%, more preferably 84 to 89 wt%, based on the heterophasic propylene copolymer; an ethylene-propylene copolymer in an amount of from 8 to 29 wt%, preferably from 10 to 29, more preferably from 11 to 29 wt%, even more preferably from 11 to 22 wt%, even more preferably from 11 to 16 wt%, based on the heterophasic propylene copolymer; and wherein the amount of units derived from ethylene is 42 to 60% by weight, more preferably 42 to 55% by weight, more preferably 45 to 51% by weight, based on the ethylene-propylene copolymer, and wherein the polypropylene composition has a melt flow rate (MFR) in the range of 0.50 to 120 dg / min wherein the melt flow rate is determined using ISO 1133-1: 2011 using 2.16 kg at 230 DEG C, and wherein the polypropylene composition has a melt flow rate (MFR) in the range of 0.50 to 120 dg / min. And a methylene sequence ngt in an amount of units derived from ethylene based on the ethylene-propylene copolymer of less than 0.30; and 5.

Description

Technical Field

[0001] The present invention relates to heterophasic polypropylene compositions having low shrinkage in combination with a good impact strength / stiffness balance.

[0002] Furthermore, the present invention also relates to an article comprising the polypropylene composition of the present invention, preferably to an article, wherein the article is produced by injection molding and / or wherein the article is a household article, a packaging article, a healthcare article or an automotive interior article. Background Art

[0003] Polymers, such as polypropylene, are increasingly being used in applications with different requirements. At the same time, tailor-made polymers that meet the requirements of these applications are constantly sought. The requirements can be challenging because many polymer properties are directly or indirectly interconnected, i.e. improving a specific property can only be achieved at the expense of another property. An example of interconnected properties in polypropylene is impact strength and stiffness.

[0004] It is known that the impact strength of polypropylene can be improved by dispersing a rubber phase within the polymer matrix, thereby obtaining a heterophasic polypropylene composition. However, this will result in a decrease in the stiffness of the polypropylene.

[0005] Stiffness can be improved, for example, by increasing the crystallinity of the composition, for example by increasing the amount of isotactic homopolymers within the composition. However, when stiffness is improved, the material becomes more brittle, which reduces impact properties.

[0006] One disadvantage of polypropylene resins is that they are subject to significant post-molding shrinkage in most molding methods. This means that in applications where dimensional tolerances are important, the mold must be customized to the specific composition and the specific molding operation to produce a finished part of the exact dimensions required.

[0007] This shrinkage problem is particularly troublesome when a manufacturer has a mold customized for a certain composition and molding operation and subsequently wishes to substitute a different composition or change the process to, for example, increase the cooling rate.

[0008] WO1996019533 cites several attempts in the art to reduce shrinkage by incorporating shrinkage control agents such as talc and inorganic fillers into polymer materials. However, the use of shrinkage control agents reduces flexibility, reduces toughness, and deteriorates the surface finish of the finished part.

[0009] Furthermore, WO1996019533 states that as an alternative to shrinkage control agents the formulation of the heterophasic polypropylene can be modified by increasing the content of the rubber phase within the polymer matrix of the heterophasic polypropylene composition.

[0010] However, the increase of the rubber phase reduces the stiffness of the heterophasic polypropylene composition. Summary of the invention

[0011] It is therefore an object of the present invention to provide a polypropylene composition having low shrinkage and at the same time a good impact strength / stiffness balance.

[0012] This object is achieved by a polypropylene composition comprising a heterophasic propylene copolymer, wherein the heterophasic propylene copolymer consists of:

[0013] Propylene homopolymer matrix in an amount of 71 to 92 wt.%, preferably 78 to 89 wt.%, more preferably 84 to 89 wt.%, based on the heterophasic propylene copolymer,

[0014] ethylene-propylene copolymer in an amount of 8 to 29 wt%, preferably 10 to 29 wt%, more preferably 11 to 29 wt%, even more preferably 11 to 22 wt%, even more preferably 11 to 16 wt%, based on the heterophasic propylene copolymer, and

[0015] wherein the amount of units derived from ethylene is from 42 to 60% by weight, more preferably from 42 to 55% by weight, more preferably from 45 to 51% by weight, based on the ethylene-propylene copolymer, and

[0016] Wherein, the polypropylene composition has

[0017] A melt flow rate (MFR) in the range of 0.50 to 120 dg / min, wherein the melt flow rate is determined using ISO 1133-1:2011 using 2.16 kg at 230°C, and

[0018] The proportion of methylene sequences n>5 in the amount of units derived from ethylene, based on the ethylene-propylene copolymer, is less than 0.32, preferably less than 0.30.

[0019] Another aspect of the present invention is a polypropylene composition comprising a heterophasic propylene copolymer, wherein the heterophasic propylene copolymer consists of:

[0020] Propylene homopolymer matrix in an amount of 71 to 92 wt.%, preferably 78 to 89 wt.%, more preferably 84 to 89 wt.%, based on the heterophasic propylene copolymer,

[0021] ethylene-propylene copolymer in an amount of 8 to 29 wt%, preferably 10 to 29 wt%, more preferably 11 to 29 wt%, even more preferably 11 to 22 wt%, even more preferably 11 to 16 wt%, based on the heterophasic propylene copolymer, and

[0022] wherein the amount of units derived from ethylene is from 42 to 60% by weight, more preferably from 42 to 55% by weight, more preferably from 45 to 51% by weight, based on the ethylene-propylene copolymer, and

[0023] Wherein, the polypropylene composition has

[0024] A melt flow rate (MFR) in the range of 0.50 to 120 dg / min, wherein the melt flow rate is determined using ISO 1133-1:2011 using 2.16 kg at 230°C, and

[0025] For methylene sequences below 16, n>5. DETAILED DESCRIPTION

[0026] Heterophasic propylene copolymer

[0027] The polypropylene composition according to the present invention comprises a heterophasic propylene copolymer. The heterophasic propylene copolymer consists of:

[0028] - a propylene homopolymer matrix in an amount of 71 to 92 wt.%, preferably 78 to 89 wt.%, more preferably 84 to 89 wt.%, based on the heterophasic propylene copolymer,

[0029] ethylene-propylene copolymer in an amount of 8 to 29 wt.-%, preferably 10 to 29 wt.-%, more preferably 11 to 29 wt.-%, even more preferably 11 to 22 wt.-%, even more preferably 11 to 16 wt.-%, based on the heterophasic propylene copolymer, and

[0030] • wherein the amount of units derived from ethylene, based on the ethylene-propylene copolymer, is from 42 to 60% by weight, more preferably from 42 to 55% by weight, more preferably from 45 to 51% by weight.

[0031] The amount of propylene homopolymer matrix and ethylene-propylene copolymer is 100 wt.%, based on the heterophasic propylene copolymer. The amount of ethylene-propylene copolymer relative to the heterophasic propylene copolymer (sometimes referred to herein as RC) and the amount of units derived from ethylene relative to the amount of ethylene-propylene copolymer in the heterophasic propylene copolymer (sometimes referred to herein as RCC2) can be determined by 13 The results were determined by C-NMR spectroscopy.

[0032] Preferably, the polypropylene composition has a cold xylene soluble content (CXS) in the range of 8 to 29 wt.-%, preferably 10 to 28 wt.-%, more preferably 11 to 22 wt.-%, even more preferably 11 to 16 wt.-%, wherein the cold xylene soluble content (CXS) is measured according to the CRYSTEX method for the heterophasic propylene copolymer of the specification.

[0033] Preferably the heterophasic propylene copolymer has a melt flow rate (MFR) in the range of 0.50 to 120 dg / min, wherein the melt flow rate is determined using ISO 1133-1:2011 using 2.16 kg at 230 °C.

[0034] In some preferred embodiments the heterophasic propylene copolymer has an MFR of 0.50 to 30 dg / min, determined using ISO 1133-1:2011 using 2.16 kg at 230 °C. In some preferred embodiments the heterophasic propylene copolymer has an MFR of 30 to 110 dg / min, determined using ISO 1133-1:2011 using 2.16 kg at 230 °C.

[0035] In some embodiments the heterophasic propylene copolymer within the polypropylene composition is prepared by visbreaking an intermediate heterophasic propylene copolymer having an initial melt flow rate (MFRinitial) as determined according to ISO 1133-1:2011 at 230 °C of 0.5 to 50, preferably 0.5 to 40, more preferably 0.5 to 25 dg / min (MFRinitial) as determined according to ISO 1133-1:2011 at 230 °C using 2.16 kg, by contacting the intermediate heterophasic propylene copolymer during melt mixing with a peroxide in such an amount that a composition comprising a heterophasic propylene copolymer having a desired final melt flow rate (MFRfinal) as determined according to ISO 1133-1:2011 at 230 °C of 0.5 to 120, preferably 0.5 to 80, more preferably 0.5 to 45 dg / min is obtained.

[0036] The term "visbreaking" is well known in the field of the present invention. For example, methods for visbreaking polypropylene are disclosed in US 4,282,076 and EP0063654.

[0037] Several different types of well-known chemical reactions can be used to visbreak the propylene polymer. One example is pyrolysis, which is achieved by exposing the polymer to high temperatures, for example above 350° C. in an extruder. Another method is exposure to strong oxidizing agents. Another method is exposure to ionizing radiation. However, it is preferred to use peroxides for visbreaking. Such materials initiate free radical chain reactions at elevated temperatures, resulting in β-fracture of the polypropylene molecules. Visbreaking can be carried out directly after polymerization and removal of unreacted monomers and before pelletization (during extrusion in an extruder, where shifting of the intermediate heterophasic propylene copolymer occurs). However, the present invention is not limited to such an embodiment, and visbreaking can also be carried out on already pelletized polypropylene, which usually contains stabilizers to prevent degradation.

[0038] Examples of suitable peroxides include organic peroxides having a decomposition half-life of less than 1 minute at the average process temperature during the visbreaking step. Suitable organic peroxides include, but are not limited to, dialkyl peroxides such as dicumyl peroxide, peroxyketals, peroxycarbonates, diacyl peroxides, peroxyesters, and peroxydicarbonates. Specific examples of these include benzoyl peroxide, dichlorobenzoyl peroxide, diisopropyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(peroxybenzoyl)-3-hexene, 1,4-bis(tert-butylperoxyisopropyl)benzene, lauroyl peroxide, tert-butyl peracetate, a,a'-bis(tert-butylperoxy)diisopropylbenzene ( 802), 2,5-dimethyl-2,5-di(tert-butylperoxy)-3-hexene, 2,5-dimethyl-2,5-di(tert-butylperoxy)-hexane, tert-butyl perbenzoate, tert-butyl perphenylacetate, tert-butyl persecanoate, tert-butyl peroxypivalate, isopropyl peroxypivalate, isopropyl hydroperoxide, diisopropyl hydroperoxide, 1,3-bis(tert-butylperoxyisopropyl)benzene, diisopropyl peroxide, tert-butyl peroxyisopropyl carbonate and any combination thereof. Preferably, dialkyl peroxide is used in the method according to the present invention. More preferably, the peroxide is a,a'-bis-(tert-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-di(tert-butylperoxy)-hexane or 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane. Preferably, the peroxide is selected from the group of non-aromatic peroxides.

[0039] A person skilled in the art can easily determine by routine experimentation how much peroxide should be used to obtain a composition with a desired melt flow rate. This also depends on the half-life of the peroxide and on the conditions used for melt mixing, which in turn depends on the exact composition.

[0040] Preferably, the propylene homopolymer matrix has a pentad isotacticity of at least 96 wt.-%, preferably at least 97 wt.-% before any visbreaking step, wherein 13 C NMR pentad isotacticity, and / or a melt flow rate (MFR) determined according to ISO 1133-1:2011 using 2.16 kg at 230° C. in the range of 0.5 to 100, preferably 0.5 to 95, more preferably 0.5 to 85, even more preferably 2 to 40 dg / min. Hopol ).

[0041] Preferably, the melt flow rate (MFR) of the ethylene-propylene copolymer is 橡胶) is in the range of 0.03 to 3.0 dg / min, preferably in the range of 0.04 to 2.5 dg / min, for example in the range of 0.05 to 2.0 dg / min, wherein MFR is calculated according to the following formula 橡胶 :

[0042] MFR rubber = 10^((Log MFR multiphase - matrix content * Log MFR Hopol ) / (rubber content))

[0043] in

[0044] MFR Heterophasic is the MFR (dg / min) of the heterophasic propylene copolymer measured according to ISO 1133-1:2011 (2.16 kg / 230°C),

[0045] MFR Hopol is the MFR (dg / min) of the propylene homopolymer matrix measured according to ISO 1133-1:2011 (2.16 kg / 230°C),

[0046] The matrix content is the fraction of the propylene homopolymer matrix in the heterophasic propylene copolymer,

[0047] The rubber content is the fraction of ethylene-propylene copolymer in the heterophasic propylene copolymer. For the avoidance of any doubt, Log in the formula means log10.

[0048] Preferably, the propylene homopolymer matrix has a molecular weight distribution (Mw / Mn) in the range of 1.0 to 11.0, more preferably in the range of 4.0 to 9.0, wherein Mw denotes the weight average molecular weight and Mn denotes the number average molecular weight, and wherein Mw and Mn are measured according to ISO 16014-1 (4):2003.

[0049] Process for the preparation of heterophasic propylene copolymers

[0050] Heterophasic propylene copolymers are generally prepared by polymerizing propylene in the presence of a catalyst and subsequently polymerizing ethylene with α-olefins in one or more reactors.

[0051] The heterophasic propylene copolymer employed in the process according to the invention may be produced using any conventional technique known to the skilled person, e.g. multistage process polymerization, such as bulk polymerization, gas phase polymerization, slurry polymerization, solution polymerization or any combination thereof. Any conventional catalyst system may be used, e.g. Ziegler-Natta or metallocene. Such techniques and catalysts are described, e.g., in WO06 / 010414; Polypropylene and other Polyolefins, Servan der Ven, Studies in Polymer Science 7, Elsevier 1990; WO06 / 010414, US4399054 and US4472524. Preferably, the heterophasic propylene copolymer is prepared using a Ziegler-Natta catalyst.

[0052] The heterophasic propylene copolymer can be prepared by a process comprising the following steps:

[0053] - polymerizing propylene in the presence of a catalyst to obtain a propylene-based substrate, and

[0054] - Subsequently polymerizing ethylene with α-olefins in a propylene-based matrix in the presence of a catalyst to obtain a heterophasic propylene copolymer. These steps are preferably carried out in different reactors. The catalysts of the first and second steps may be different, but are preferably the same.

[0055] catalyst

[0056] Ziegler-Natta catalyst systems are well known in the art. The term generally refers to a catalyst comprising a solid catalyst compound containing a transition metal (procatalyst) and an organometallic compound (cocatalyst). Optionally, one or more electron donor compounds (external donors) may also be present in the catalyst.

[0057] The transition metal in the transition metal-containing solid catalyst compound is usually selected from Groups 4 to 6 of the Periodic Table of Elements (latest IUPAC notation); more preferably, the transition metal is selected from Group 4; most preferably, titanium (Ti) is used as the transition metal.

[0058] Although various transition metals can be applied, it is most preferred that titanium is concerned below. However, it is also applicable to the use of other transition metals different from Ti. The titanium-containing compound that can be used as the transition metal compound in the present invention is generally loaded on a carrier containing magnesium and / or containing inorganic oxides (such as silicon oxide or aluminum oxide) that is insoluble in hydrocarbons, and is generally combined with an internal electron donor compound. The solid catalyst compound containing the transition metal can be formed, for example, by reacting titanium halide (IV), an organic internal electron donor compound and a magnesium-containing and / or silicon-containing carrier. The solid catalyst compound containing the transition metal can be further processed or modified with other electron donors or Lewis acid species, and / or can be subjected to one or more washing procedures, as well known in the art.

[0059] Some examples of Ziegler-Natta (pro)catalysts which may be suitably used for the preparation of heterophasic propylene copolymers and methods for their preparation may be found in EP 1 273 595, EP 0 019 330, US 5,093,415, Example 2 of US 6,825,146, US 4,771 ,024 column 10, line 61 to column 11, line 9, WO 03 / 068828, US 4,866,022, WO 96 / 32426 A, Example 1 of WO 2007 / 134851 A1 and WO 2015 / 091983, all of which are hereby incorporated by reference.

[0060] The (pro)catalyst thus prepared can be used in the polymerization of heterophasic propylene copolymers using an external donor such as exemplified herein and a cocatalyst such as exemplified herein.

[0061] In a preferred embodiment, a phthalate-free catalyst is used to make the heterophasic propylene copolymer.

[0062] Because of the increasingly stringent government regulations on the maximum phthalate content of polymers, it is preferred to use so-called phthalate-free internal donors. In the context of the present invention, "substantially phthalate-free" or "phthalate-free" means having a phthalate content based on the total weight of the catalyst that is lower than, for example, 150ppm, alternatively lower than, for example, 100ppm, alternatively lower than, for example, 50ppm, alternatively, for example, lower than 20ppm, for example, 0ppm. The example of phthalates includes, but is not limited to, dialkyl phthalates, wherein the alkyl group contains from about two to about ten carbon atoms. The example of phthalates includes, but is not limited to, diisobutyl phthalate, ethylbutyl phthalate, diethyl phthalate, di-n-butyl phthalate, bis(2-ethylhexyl)phthalate and diisodecyl phthalate.

[0063] Examples of phthalate-free internal donors include, but are not limited to, 1,3-diethers, such as 3,3-bis(methoxymethyl)-2,6-dimethylheptane, 9,9-bis(methoxymethyl)fluorene, optionally substituted malonates, maleates, succinates, glutarates, benzoates, cyclohexene-1,2-dicarboxylate, benzoates, citraconates, aminobenzoates, silyl esters, and derivatives and / or mixtures thereof.

[0064] The catalyst comprising a Ziegler-Natta procatalyst may be activated with an activator, for example an activator selected from benzamides and monoesters, such as alkyl benzoates.

[0065] Catalyst includes cocatalyst. " Cocatalyst " used herein is a term well known in the art in the field of Ziegler-Natta catalysts, and is considered to be a material capable of converting a primary catalyst into an active polymerization catalyst. Generally speaking, a cocatalyst is an organometallic compound of a metal of the 1st, 2nd, 12th or 13th family containing the periodic system (Handbook of Chemistry and Physics, the 70th edition, CRC Press, 1989-1990). Cocatalyst can include any compound known in the art to be used as "cocatalyst", such as hydride, alkylate or arylate of aluminum, lithium, zinc, tin, cadmium, beryllium, magnesium and their combination. Cocatalyst can be a hydrocarbyl aluminum cocatalyst, as known to technicians. Preferably, the cocatalyst is selected from trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, trihexyl aluminum, diisobutyl aluminum hydride, trioctyl aluminum, dihexyl aluminum hydride and their mixture, and most preferably, the cocatalyst is triethyl aluminum (abbreviated as TEAL).

[0066] Examples of external donors are known to those skilled in the art and include, but are not limited to, external electron donors selected from the group consisting of compounds having a structure according to formula III (R 90 )2N—Si(OR 91 )3, having a structure according to Formula IV: (R 92 )Si(OR 93 )3, and mixtures thereof, wherein R 90 , R 91 , R 92 and R 93 Each of the groups is independently a linear, branched or cyclic substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, preferably wherein R 90 , R 91 , R 92 and R 93The groups are each independently a straight-chain unsubstituted alkyl group having 1 to 8 carbon atoms, such as ethyl, methyl or n-propyl, such as diethylaminotriethoxysilane (DEATES), n-propyltriethoxysilane (nPTES), n-propyltrimethoxysilane (nPTMS); and alkyl groups having the general formula Si(OR a ) 4-n R b n An organosilicon compound, wherein n may be 0 to 2, and R a and R b Each of independently represents an alkyl or aryl group, optionally containing one or more heteroatoms such as O, N, S or P, having, for example, 1-20 carbon atoms; such as diisobutyldimethoxysilane (DiBDMS), tert-butylisopropyldimethoxysilane (tBuPDMS), cyclohexylmethyldimethoxysilane (CHMDMS), dicyclopentyldimethoxysilane (DCPDMS) or diisopropyldimethoxysilane (DiPDMS). More preferably, the external electron donor is selected from diisopropyldimethoxysilane (DiPDMS) or diisobutyldimethoxysilane (DiBDMS).

[0067] Preferably, the heterophasic propylene copolymer is produced in a sequential multi(stage) reactor polymerization process, e.g. in a gas phase process, in the presence of a catalyst comprising:

[0068] a) a Ziegler-Natta procatalyst comprising a compound of a transition metal of Group 4 to 6 of IUPAC, a Group 2 metal compound and an internal donor, wherein the internal donor is preferably a non-phthalic compound, more preferably a non-phthalate ester, even more preferably wherein the internal donor is selected from, for example, 3,3-bis(methoxymethyl)-2,6-dimethylheptane, 9,9-bis(methoxymethyl)fluorene, optionally substituted malonates, maleates, succinates, glutarates, benzoates, cyclohexene-1,2-dicarboxylates, benzoates, citraconates, aminobenzoates, silyl esters and derivatives and / or mixtures thereof;

[0069] b) a promoter (Co), and

[0070] c) Optional external donor.

[0071] Preferably, the Ziegler-Natta procatalyst is prepared by a process comprising the following steps:

[0072] a) making compound R 4 z MgX 4 2-z contacting with an alkoxy- or aryloxy-containing silane compound to produce a first intermediate reaction product, namely solid Mg(ORa ) x X 1 2-x , wherein: R a is a straight-chain, branched or cyclic hydrocarbon group independently selected from the group consisting of alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups and one or more combinations thereof; wherein the hydrocarbon group may be substituted or unsubstituted, may contain one or more heteroatoms and preferably has 1 to 20 carbon atoms; wherein R 4 is a straight-chain, branched or cyclic hydrocarbon group independently selected from the group consisting of alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups and one or more combinations thereof; wherein the hydrocarbon group may be substituted or unsubstituted, may contain one or more heteroatoms and preferably has 1 to 20 carbon atoms, preferably R 4 is butyl; wherein X 4 and X 1 are each independently selected from the group consisting of fluoride ion (F-), chloride ion (Cl-), bromide ion (Br-) or iodide ion (I-), preferably chloride ion; z is in the range greater than 0 and less than 2, i.e., 0 < z < 2, and x is an integer from 0 to 2;

[0073] b) Optionally, contacting the solid Mg(OR a ) x X 1 2-x obtained in step i) with at least one activating compound selected from the group consisting of activating electron donors and metal alkoxide compounds of the formula M 1 (OR b ) v-w (OR 3 ) w or M 2 (OR b ) v-w (R 3 ) w to obtain a second intermediate; wherein: M 1 is a metal selected from the group consisting of Ti, Zr, Hf, Al or Si; v is the valence of M 1 ; M 2 is metal Si; v is the valence of M 2 ; R b and R 3 are each independently selected from the group consisting of alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups and one or more combinations thereof; wherein the hydrocarbon group may be substituted or unsubstituted, may contain one or more heteroatoms and preferably has 1 to 20 carbon atoms; wherein w is less than v, preferably v is 3 or 4;

[0074] c) contacting the first intermediate reaction product or the second intermediate reaction product obtained in step i) or ii) respectively with a halogen-containing Ti compound and an internal electron donor.

[0075] In a preferred embodiment, the catalyst used to prepare the polypropylene composition according to the present invention is a catalyst described in detail in WO2021 / 063930, which is incorporated herein by reference. The catalyst comprises a main catalyst, a cocatalyst and an external electron donor. The cocatalyst and the external electron donor may be those mentioned above.

[0076] In one embodiment, as activating compound during step ii), an alcohol is used as activating electron donor and a tetraalkyl titanate is used as metal alkoxide compound.

[0077] In one embodiment, an activator is present. In one embodiment, the activator is ethyl benzoate. In one embodiment, the activator is a benzamide according to formula X:

[0078]

[0079] Where R 70 and R 71 are each independently selected from hydrogen or alkyl, and R 72 , R 73 , R 74 , R 75 , R 76 Each is independently selected from hydrogen, a heteroatom or a hydrocarbon group, which is preferably selected from an alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl group and one or more combinations thereof, more preferably wherein R 70 and R 71 are all methyl and R 72 , R 73 , R 74 and R 75 All are hydrogen, namely N,N'-dimethylbenzamide (Ba-2Me).

[0080] In these preferred embodiments, the internal electron donor used in the process for preparing the procatalyst is a compound according to formula I:

[0081]

[0082] Where R 1 is a secondary alkyl group and R 2 is a non-secondary alkyl group having at least 5 carbon atoms, preferably R 2 is a non-secondary alkyl group having at least 5 carbon atoms, which is branched at the 3-position or at another position.

[0083] Preferably, the internal electron donor used is according to formula I:

[0084]

[0085] Where R 1 is a secondary alkyl group (C3) having at least three carbon atoms, and R 2 is a non-secondary alkyl group having at least 5 carbon atoms, preferably R 1 and R 2 has up to seven carbon atoms (C7), preferably up to six carbon atoms (C6), preferably isopropyl, isobutyl, isopentyl, cyclopentyl, n-pentyl and isohexyl. Preferably, R 2 Branching at position 3 or another position.

[0086] In another embodiment, the internal electron donor is 3,3-bis(methoxymethyl)-2,6-dimethylheptane, according to Formula I, wherein R 1 isopropyl, i.e., a secondary alkyl group, and R 2 is an isopentyl group, i.e. a non-secondary alkyl group and having a branch on the third carbon atom (abbreviated as iPiPen, where iP stands for isopropyl and iPen stands for isopentyl, also known as 3-methyl-butyl). The compound iPiPen has C 13 H 28 Chemical formula of O2; exact mass of 216.21 and molecular weight of 216.37. In a more specific embodiment, iPiPen is used as internal donor and N,N-dimethylbenzamide is preferably used as activator.

[0087]

[0088] In another embodiment, the internal electron donor is (1-methoxy-2-(methoxymethyl)-5-methylhexan-2-yl)cyclopentane, according to Formula I, wherein R 1 is a secondary alkyl cyclopentyl and R 2 is a secondary cyclopentyl group (abbreviated as CPiPen, where CP represents cyclopentyl and iPen represents isopentyl, also known as 3-methyl-butyl). 15 H 30 Chemical formula of O2; exact mass of 242.22 and molecular weight of 242.40. In a more specific embodiment, CPiPen is used as internal donor and N,N-dimethylbenzamide is preferably used as activator.

[0089]

[0090] In another embodiment, the internal electron donor is 3,3-bis(methoxymethyl)-2,7-dimethyloctane, according to Formula I, wherein R1 isopropyl secondary alkyl and R 2 is a non-secondary isohexyl radical with a branch on the third carbon atom (abbreviated as iPiHex, where iP represents isopropyl and iHex represents isohexyl, also known as 4-methyl-pentyl). The compound iPiHex has C 14 H 30 Chemical formula of O2; exact mass of 230.22 and molecular weight of 230.39. In a more specific embodiment, iPiHex is used as internal donor and N,N-dimethylbenzamide is preferably used as activating agent.

[0091]

[0092] In another embodiment, the internal electron donor is 3,3-bis(methoxymethyl)-2-methyloctane, according to Formula I, wherein R 1 isopropyl secondary alkyl and R 2 is a non-secondary non-branched n-pentyl group (abbreviated as iPnPen, wherein iP represents isopropyl and nPen represents n-pentyl). The compound iPnPen has C 13 H 28 Chemical formula of O2; exact mass of 216.21 and molecular weight of 216.37. In a more specific embodiment, iPnPen is used as internal donor and N,N-dimethylbenzamide is preferably used as activator.

[0093]

[0094] In another embodiment, the internal electron donor is 3,3-bis(methoxymethyl)-2,6-dimethyloctane, according to Formula I, wherein R 1 isopropyl secondary alkyl and R 2 is a non-secondary branched isohexyl radical having a branch at the third carbon atom (abbreviated as iPiHex, where iP represents isopropyl and iHex represents isohexyl, also known as 3-methyl-pentyl). The compound iPiHex has C 14 H 32 Chemical formula of O2; exact mass of 230.22 and molecular weight of 230.39. In a more specific embodiment, iPiHex is used as internal donor and N,N-dimethylbenzamide is preferably used as activating agent.

[0095]

[0096] In one embodiment, the substituent R 1 is isopropyl or cyclopentyl. In one embodiment, the substituent R 2 The following table shows the above embodiments together with their abbreviations and R1 and R 2 groups, whether these groups are secondary and whether they are branched.

[0097] According to the present invention, it is also preferred that R 1 is a secondary alkyl group, and R 2 is a non-secondary alkyl group which is branched at the 3-position or another position.

[0098]

[0099] Preferably, the molar ratio of Al in the promoter to Si in the external electron donor is from 1 to 120, such as at least 1 and at most 15, or greater than 15 and at most 120.

[0100] Preferably, the molar ratio of Si in the external electron donor to Ti in the main catalyst is 10 to 30.

[0101] Preferably, the molar ratio of Al in the co-catalyst to Ti in the main catalyst is 50 to 170.

[0102] Preferably, the terminal n-butyl group ( / 1000C) ranges from 0.01 to 0.50, preferably from 0.05 to 0.35, more preferably from 0.09 to 0.30.

[0103] Composition

[0104] The polypropylene composition has a melt flow rate (MFR) in the range of 0.50 to 120 dg / min, wherein the melt flow rate is determined using ISO 1133-1:2011 using 2.16 kg at 230°C. In some preferred embodiments, the MFR of the polypropylene composition measured using ISO 1133-1:2011 using 2.16 kg at 230°C is from 0.50 to 30 dg / min. In some preferred embodiments, the MFR of the polypropylene composition measured using ISO 1133-1:2011 using 2.16 kg at 230°C is from 30 to 120 dg / min.

[0105] In one embodiment of the present invention, the polypropylene composition has less than 16 methylene sequences n>5, wherein by means of C 13-NMR determination of the methylene sequence n>5, preferably according to the methodology described by JC Randall in "Polymer sequence determination Carbon 13 NMR Method", Academic Press (1977) and in "Methylene Sequence Distribution and number average sequences lengths in ethylene-propylene copolymer", Macromolecules Vol. 11, No1, p33, (1978).

[0106] In one embodiment of the present invention, the polypropylene composition has a proportion of methylene sequences n>5 in the amount of units derived from ethylene, based on the ethylene-propylene copolymer, of less than 0.32, preferably less than 0.30, wherein by means of C 13 -NMR determination of the methylene sequence n>5, preferably according to the methodology described by JC Randall in "Polymer sequence determination Carbon 13 NMR Method", Academic Press (1977) and in "Methylene Sequence Distribution and number average sequences lengths in ethylene-propylene copolymer", Macromolecules Vol. 11, No 1, p 33, (1978).

[0107] Preferably, the amount of heterophasic propylene copolymer is at least 95 wt.-%, preferably more than 96 wt.-%, more preferably more than 97 wt.-%, even more preferably more than 98 wt.-%, based on the polypropylene composition.

[0108] Inorganic fillers

[0109] The composition according to the present invention may contain an inorganic filler. Suitable examples of inorganic fillers include talc, calcium carbonate, wollastonite, barium sulfate, kaolin, glass flakes, layered silicates (bentonite, montmorillonite, montmorillonite) and mica. For example, the inorganic filler is selected from talc, calcium carbonate, wollastonite, mica and mixtures thereof. More preferably, the inorganic filler is talc.

[0110] Preferably, the inorganic filler has a median diameter d50, determined according to ISO 13320-1:2020, of 5 to 20 μm, preferably 3 to 15 μm.

[0111] The composition according to the invention may be free or substantially free of inorganic fillers. For example, the composition according to the invention may comprise less than 1.0 wt%, less than 0.1 wt% or less than 0.01 wt% of inorganic fillers.

[0112] additive

[0113] In some embodiments, the polypropylene composition additionally comprises additives, e.g. in an amount of 0.10 to 1.0 wt.-%, based on the polypropylene composition.

[0114] Suitable additives include, but are not limited to, stabilizers. The stabilizer may, for example, be selected from a heat stabilizer, an antioxidant and / or a UV stabilizer. Examples include conventional stabilizers such as Irgafos 168, Irganox 1010 and / or Irganox B225.

[0115] Additives may further include nucleating agents, colorants such as pigments and dyes; clarifying agents; surface tension adjusting agents; lubricants; flame retardants; mold release agents; flow improvers; plasticizers; antistatic agents; foaming agents; and slip agents.

[0116] In one aspect, the present invention provides an article comprising a polypropylene composition of the present invention. Preferably, based on the article, the amount of the polypropylene composition is at least 95% by weight. Preferably, the article is prepared by injection molding. Preferably, the article is a household article, such as a vacuum cleaner housing, household chemicals and paint, or a packaged article, such as a container, a crate, a box, a battery shell, a bucket, a flower pot, a food container / package, an ice cream container, a thin-walled package, a lid and a closure, a health care package, or a health care article, such as a drug delivery article, a laboratory ware, a medical device, a medical diagnostic article, or an automotive interior article, such as a dashboard bracket, a door panel, an instrument panel, an instrument panel bracket, a door cladding, a door fixture, an armrest, a pillar cladding, a seat cladding, a trunk cladding, an interior decoration, and applications in heating, ventilation, and air conditioning (HVAC) applications.

[0117] In one aspect, the present invention provides the use of the polypropylene composition of the present invention for preparing articles. Preferably, based on the article, the amount of the polypropylene composition is at least 95% by weight. Preferably, the article is prepared by injection molding. Preferably, the article is a household article, such as a vacuum cleaner housing, household chemicals and paint, or a packaged article, such as a container, a crate, a box, a battery shell, a bucket, a flower pot, a food container / package, an ice cream container, a thin-walled package, a lid and a closure, a health care package, or a health care article, such as a drug delivery article, a laboratory ware, a medical device, a medical diagnostic article, or an automotive interior article, such as a dashboard bracket, a door panel, an instrument panel, an instrument panel bracket, a door cladding, a door fixture, an armrest, a pillar cladding, a seat cladding, a trunk cladding, an interior decoration, and applications in heating, ventilation, and air conditioning (HVAC) applications.

[0118] In one aspect, the present invention provides a method for preparing an article, comprising the steps of:

[0119] a. Provide a polypropylene composition of the present invention, and

[0120] b. Converting the polypropylene composition into an article, for example by using extrusion or injection molding methods.

[0121] In one aspect, the present invention provides a process for preparing a polypropylene composition according to the present invention, comprising:

[0122] i) polymerizing propylene in the presence of a catalyst to obtain a propylene homopolymer matrix, and

[0123] ii) subsequently polymerizing ethylene with propylene in the presence of a catalyst in a propylene homopolymer matrix to obtain a heterophasic propylene copolymer,

[0124] Preferably, steps i) and ii) are carried out in different reactors,

[0125] wherein steps i) and ii) are carried out in the presence of a catalyst comprising

[0126] a. A Ziegler-Natta procatalyst comprising a compound of a transition metal of Group 4 to 6 of IUPAC, a Group 2 metal compound and an internal donor, wherein the internal donor is a non-phthalic acid compound, more preferably a non-phthalate ester, even more preferably wherein the internal donor is selected from, for example, 3,3-bis(methoxymethyl)-2,6-dimethylheptane, 9,9-bis(methoxymethyl)fluorene, optionally substituted malonates, maleates, succinates, glutarates, benzoates, cyclohexene-1,2-dicarboxylates, benzoates, citraconates, aminobenzoates, silyl esters and derivatives and / or mixtures thereof;

[0127] b. a promoter (Co), and

[0128] c. Optional external donor.

[0129] Although the present invention has been described in detail for purposes of illustration, it should be understood that such details are solely for that purpose and variations may be made therein by one skilled in the art without departing from the spirit and scope of the present invention as defined by the claims.

[0130] It is further noted that the present invention relates to any possible combination of features described herein, including all possible combinations of embodiments described herein, preferably in particular those combinations of features or embodiments presented in the claims. Thus, it will be appreciated that all combinations of features or embodiments relating to compositions according to the invention; all combinations of features or embodiments relating to methods according to the invention; and all combinations of features or embodiments relating to compositions according to the invention with features or embodiments relating to methods according to the invention are described herein.

[0131] It is also noted that the term "comprising / including / containing" does not exclude the presence of other elements. However, it is also understood that a description of a product / composition comprising certain components also discloses a product / composition consisting of these components. A product / composition consisting of these components may be advantageous because it provides a simpler and more economical method for preparing the product / composition. Similarly, it is also understood that a description of a method comprising certain steps also discloses a method consisting of these steps. A method consisting of these steps may be advantageous because it provides a simpler and more economical method.

[0132] The invention is now explained with the aid of the following examples without, however, being restricted thereto.

[0133] Example

[0134] Method for preparing primary catalyst

[0135] For Examples E1, E2 and E3 of the present invention: the main catalyst was prepared according to the method disclosed in Example 1 of WO2021 / 063930A1;

[0136] For comparative examples CE1, CE2 and CE3: the procatalyst was prepared according to the method disclosed in Example 1 of US 4,866,022.

[0137] Process conditions of embodiments E1, E2, E3, CE1, CE2 and CE3 of the present invention

[0138] The gas phase polymerization to produce the heterophasic propylene copolymers E1, E2, E3, CE1, CE2 and CE3 was carried out in a set of two horizontal cylindrical stirred bed gas phase reactors connected in series.

[0139] In the first reactor (R1) a homopolymer is formed and in the second reactor (R2) an ethylene-propylene copolymer (also referred to as "rubber" or "rubber phase" in the examples) is formed to produce a heterophasic propylene copolymer. Both reactors are operated in continuous mode.

[0140] During operation, the polypropylene powder produced in the first reactor is discharged into the second reactor through the powder discharge system.

[0141] The temperature of the powder bed is measured by a series of internal thermocouples. The data from these thermocouples is used to control the quench flow to the various quench nozzles.

[0142] Hydrogen is fed to both reactors independently to control the melt flow index ratio of the homopolymer powder and the copolymer powder. In this regard, RCC2 is the amount of ethylene incorporated in the rubber fraction (wt%) and RC is the amount of rubber incorporated in the heterophasic propylene copolymer (wt%), as determined by 13 Determined by C-NMR spectroscopy.

[0143] Table 1. Reaction conditions for heterophasic copolymer compositions

[0144]

[0145] Si / Ti is the ratio of external donor (DiPDMS) to main catalyst

[0146] Al / Si is the ratio of co-catalyst (TEAL) to external donor (DiPDMS)

[0147] H2 / C3 is the molar ratio of hydrogen to propylene

[0148] C2 / C3 is the molar ratio of ethylene to propylene.

[0149] Table 2. Molecular properties

[0150]

[0151] Granulation of E1, E2, E3, CE1, CE2 and CE3

[0152] Pellets were prepared from powder compositions E1, E2, E3, CE1, CE2 and CE3 by extrusion process in a twin screw.

[0153] The corresponding compositions of Examples E4 and CE4 were prepared by extruding E1 and CE1 powders, respectively, in a twin screw with 500 ppm Irganox 1010, 500 pm Irgafos 168 and 500 ppm calcium stearate.

[0154] The corresponding compositions of Examples E5 and CE5 were prepared by extruding E1 and CE1 powders, respectively, in a twin screw with 500 ppm Irganox 1010, 500 pm Irgafos 168, 500 ppm calcium stearate and 500 ppm Mina 11 from Milliken as alpha-nucleating agent and 0.025 wt% Luperox 101M050.

[0155] By in a mixture with 500 ppm Irganox 1010, 500 pm Irgafos 168 and 500 ppm calcium stearate and 0.5 wt% talc as an α-nucleating agent and 250 ppm from Milliken The corresponding compositions of Examples E6 and CE6 were prepared by extruding E2 and CE2 powders, respectively, in a twin screw extruder containing HPN20E, 2000 ppm Atmer 129, an antistatic agent, and 0.025 wt% Luperox 101M050.

[0156] The corresponding compositions of Examples E7 and CE7 were prepared by extruding E3 and CE3 powders, respectively, in a twin screw with 0.1215 wt% peroxide + 0.05 wt% calcium stearate + 0.5 wt% talc + 0.2 wt% Irg B225.

[0157] Table 3. Properties of Examples E3, E4, E5, E6, E7 and Comparative Examples CE3, CE4 and CE5 and CE6 and CE7

[0158]

[0159] As can be seen from the above table, the multiphase PP composition according to the present invention shows less shrinkage without adding a rubber phase (which would affect the stiffness of the material).

[0160] Measurement method

[0161] Shrinkage method:

[0162] Shrinkage 3D measurement ISO 294-4 (+1 hour 90°C), at 23°C, after 1 day

[0163] MFR

[0164] MFRhopol, MFRinitial and MFRfinal of the heterophasic propylene copolymer composition, matrix phase and dispersed phase are measured according to ISO 1133 using 2.16 kg load at 230 °C.

[0165] Impact strength

[0166] The impact strength was determined by measuring the Izod impact strength according to ISO 180 4A at 23° C., 0° C. and −20° C. Test geometry: 65*12.7*3.2 mm, according to ISO 37 / 2, notch 45°, vertical orientation.

[0167] Flexural modulus

[0168] Flexural modulus was determined according to ASTM D790-10 at 23°C in parallel (II) orientation. Test geometry: 65*12.7*3.2 mm.

[0169] RC, RCC2 and TC2

[0170] use 13 C-NMR spectroscopy was used to measure RC and RCC2. To this end, approximately 150 mg of material was dissolved in 1,1,2,2-tetrachloroethane-d2 (TCE-d2). To ensure a homogeneous solution, sample preparation was performed in a heated rotary oven. NMR measurements were performed in solution using a Bruker 500Advance III HD spectrometer running 1H and 13C at 500.16 and 125.78 MHz, respectively, and equipped with a 10 mm dual cryogenically cooled probe head running at 125 °C. 13C-NMR experiments were performed using standard single pulse excitation with NOE and two-level WALTZ16 decoupling scheme (Zhou Z. et al. J. Mag. Reson 187 (2007) 225. A total of 512 transients were acquired for each spectrum. The spectra were calibrated by setting the central signal of the triplet state of TCE at 74.2 ppm. Quantitative 13C NMR spectra were processed, integrated and relevant quantitative properties determined from the integrals using a proprietary computer program.

[0171] The total ethylene content (TC2) of the copolymer was calculated from RC and RCC2.

[0172] CRYSTEX Method

[0173] The CRYSTEX method described in WO2019179959 and herein can determine the following properties of heterophasic propylene copolymers:

[0174] - Amount of amorphous soluble fraction (CXS) in the heterophasic propylene copolymer.

[0175] The measurement of this property can be carried out according to the CRYSTEX method by a CRYSTEX QC instrument of the CRYSTEX QC Polymer Char (Valencia, Spain). A schematic diagram of the CRYSTEX QC instrument is given in Del Hierro, P.; Ortin, A.; Monrabal, B.; 'Soluble Fraction Analysis in polypropylene, The Column', February 2014, pp. 18-23.

[0176] The CRYSTEX QC instrument includes an infrared detector (IR4) and an online dual capillary viscometer. Quantification is accomplished by an infrared detector that detects IR absorbance in two different bands (CH3 and CH2).

[0177] The machine was calibrated using the cold xylene soluble (CXS) fraction and the cold xylene insoluble (CXI) fraction of various propylene polymers with known CXS content determined by standard gravimetric method according to ISO16152.

[0178] CRYSTEX process for heterophasic propylene copolymers

[0179] A sample of the heterophasic propylene copolymer to be analyzed was weighed at a concentration of 5 mg / mL. After automatically filling the vial with 1,2,4-TCB containing 250 mg / L 2,6-tert-butyl-4-methylphenol (BHT) as antioxidant, the sample was dissolved at 170°C until complete dissolution was achieved, for 120 min, while continuously stirring at 800 rpm.

[0180] CRYSTEX process for propylene homopolymers

[0181] A sample of the PP homopolymer to be analyzed (out of the first reactor: propylene homopolymer matrix) was weighed at a concentration of 10 mg / mL. After automatically filling the vial with 1,2,4-TCB containing 250 mg / L 2,6-tert-butyl-4-methylphenol (BHT) as an antioxidant, the sample was dissolved at 170°C until complete dissolution was achieved, for 60 min, while continuously stirring at 800 rpm.

[0182] Methylene sequence n>5

[0183] The number of weight percent of methylene groups present between two consecutive methyl and methylene groups in the polymer chain is relative to the total number of uninterrupted methylene sequences (greater than 5) and is calculated according to the methodology described by JC Randall in "Polymer sequence determination Carbon 13 NMR Method", Academic Press 1977 and in "Methylene Sequence Distribution and number average sequences lengths in ethylene-propylene copolymer" Macromolecules Vol. 11, No 1, p 33, (1978) with the aid of 13 C-NMR determination.

[0184] Terminal n-butyl ( / 1000C)

[0185] The terminal n-butyl groups ( / 1000C) were determined according to Carvill et al., Macromolecules 1998, 31, 3783-3789, wherein the signal at 14.15 ppm was measured in TCE-d2 at 125°C. 13 C NMR spectra, the spectra were calibrated using the TCE signal at 74.2 ppm and a chemical shift correction of +2.1 ppm was used to account for the measurement temperature difference of Carvill et al. to 125°C, as used in the methods of the Examples herein. The number of n-butyl end groups is expressed as "per 1000C ( / 1000C)".

[0186] Isotacticity 13 C NMR

[0187] 175 mg of polypropylene pellets were dissolved in 3 ml of deuterated tetrachloroethylene (C2D2Cl4) containing 2,6-di-tert-butyl-4-methylphenol (BHT) at 130°C (5 mg BHT in 200 ml C2D2Cl). The spectra were recorded on a Bruker Avance 500 spectrometer equipped with a cryogenically cooled probe head operating at 125°C. 13 C NMR spectroscopy.

[0188] The isotacticity of the mmmm pentad level is given by 13 C NMR spectroscopy measurements, in % based on total pentad amount.

[0189] GPC / SEC

[0190] The number average molecular weight (Mn), weight average molecular weight (Mw) and Z average molecular weight (Mz) were determined using ISO16014-1(4):2003. SEC-DV was used with universal calibration. SEC measurements were performed on a PolymerChar GPC system. The sample was dissolved in 1,2,4-trichlorobenzene (TCB) stabilized with 1 g / L butylhydroxytoluene (BHT) at a concentration of 0.3-1.3 mg / mL at 160°C for 4 hours. 300 μL of the polymer solution was injected with a mobile phase flow rate of 1.0 ml / min. Infrared detection IR5 MCT and a differential viscometer were used. To establish a universal calibration line, polyethylene standards were used.

Claims

1. A polypropylene composition comprising a heterophasic propylene copolymer, Wherein the heterophasic propylene copolymer consists of: - a propylene homopolymer matrix in an amount of 71 to 92 wt.%, preferably 78 to 89 wt.%, more preferably 84 to 89 wt.%, based on the heterophasic propylene copolymer, ethylene-propylene copolymer in an amount of 8 to 29 wt%, preferably 10 to 29, more preferably 11 to 29 wt%, even more preferably 11 to 22 wt%, even more preferably 11 to 16 wt%, based on the heterophasic propylene copolymer, and ●Among them, The amount of units derived from ethylene, based on the ethylene-propylene copolymer, is from 42 to 60% by weight, more preferably from 42 to 55% by weight, more preferably from 45 to 51% by weight, and Wherein, the polypropylene composition has a melt flow rate (MFR) in the range of 0.50 to 120 dg / min, wherein the melt flow rate is determined using ISO 1133-1:2011 using 2.16 kg at 230°C, and • A proportion of methylene sequences n>5 in the amount of units derived from ethylene, based on the ethylene-propylene copolymer, of less than 0.32, preferably less than 0.

30.

2. A polypropylene composition comprising a heterophasic propylene copolymer, Wherein the heterophasic propylene copolymer consists of: - a propylene homopolymer matrix in an amount of 71 to 92 wt.%, preferably 78 to 89 wt.%, more preferably 84 to 89 wt.%, based on the heterophasic propylene copolymer, ethylene-propylene copolymer in an amount of 8 to 29 wt%, preferably 10 to 29, more preferably 11 to 29 wt%, even more preferably 11 to 22 wt%, even more preferably 11 to 16 wt%, based on the heterophasic propylene copolymer, and ●Among them, The amount of units derived from ethylene, based on the ethylene-propylene copolymer, is from 42 to 60% by weight, more preferably from 42 to 55% by weight, more preferably from 45 to 51% by weight, and Wherein, the polypropylene composition has a melt flow rate (MFR) in the range of 0.50 to 120 dg / min, wherein the melt flow rate is determined using ISO 1133-1:2011 using 2.16 kg at 230°C, and ●Methylene sequences below 16 n>5.

3. A polypropylene composition according to any of the preceding claims, wherein the heterophasic propylene copolymer within the polypropylene composition is prepared by visbreaking an intermediate heterophasic propylene copolymer having an initial melt flow rate (MFRinitial) determined according to ISO 1133-1:2011 at 230 °C of 0.5 to 50, preferably 0.5 to 40, more preferably 0.5 to 25 dg / min (MFRinitial) determined according to ISO 1133-1:2011 at 230 °C using 2.16 kg, with a peroxide in such an amount that a composition comprising the heterophasic propylene copolymer having a desired final melt flow rate (MFRfinal) determined according to ISO 1133-1:2011 at 230 °C of 0.5 to 120, preferably 0.5 to 80, more preferably 0.5 to 45 dg / min (MFRfinal) is obtained.

4. The polypropylene composition according to anyone of the preceding claims, wherein the polypropylene composition has a cold xylene soluble content (CXS) in the range of 8 to 29 wt.-%, preferably 10 to 28, more preferably 11 to 22 wt.-%, even more preferably 11 to 16 wt.-%, wherein the cold xylene soluble content (CXS) is measured according to the CRYSTEX method for heterophasic propylene copolymers of the specification.

5. The polypropylene composition according to anyone of the preceding claims, wherein the propylene homopolymer matrix has a cold xylene soluble content (CXS) in the range of 1 to 4 wt.-%, preferably 1 to 3 wt.-%, wherein the cold xylene soluble content (CXS) is measured according to the CRYSTEX method for propylene homopolymers of the specification.

6. The polypropylene composition according to any of the preceding claims, wherein the propylene homopolymer matrix prior to any visbreaking step has a. at least 96% by weight, preferably at least 97% by weight, of the pentad isotacticity, wherein the use 13 C NMR to determine the isotacticity of the pentad, and / or b. Melt flow rate (MFR) measured according to ISO 1133-1:2011 using 2.16 kg at 230 ° C in the range of 0.5 to 100, preferably 0.5 to 95, more preferably 0.5 to 85, even more preferably 2 to 40 dg / min Hopol ).

7. Polypropylene composition according to anyone of the preceding claims, wherein the heterophasic propylene copolymer has less than 16 methylene sequences n>5.

8. Polypropylene composition according to anyone of the preceding claims, wherein the amount of heterophasic propylene copolymer is at least 95 wt.-%, based on the polypropylene composition, and / or the polypropylene composition additionally comprises additives, e.g. in an amount of 0.10 to 2.0 wt.-%, based on the polypropylene composition.

9. The polypropylene composition according to any of the preceding claims, wherein the heterophasic propylene copolymer is produced in a sequential multi-reactor polymerization process in the presence of a catalyst comprising: a) a Ziegler-Natta procatalyst comprising a compound of a transition metal of Group 4 to 6 of IUPAC, a Group 2 metal compound and an internal donor, wherein the internal donor is preferably a non-phthalic compound, more preferably a non-phthalate ester, even more preferably wherein the internal donor is selected from, for example, 3,3-bis(methoxymethyl)-2,6-dimethylheptane, 9,9-bis(methoxymethyl)fluorene, optionally substituted malonates, maleates, succinates, glutarates, benzoates, cyclohexene-1,2-dicarboxylates, benzoates, citraconates, aminobenzoates, silyl esters and derivatives and / or mixtures thereof; b) a promoter (Co), and c) Optional external donor.

10. The polypropylene composition according to claim 7, wherein the Ziegler-Natta procatalyst is prepared according to the following steps: a. Make compound R 4 z MgX 4 2-z contacting with an alkoxy- or aryloxy-containing silane compound to produce a first intermediate reaction product, namely solid Mg(OR a ) x X 1 2-x ,in: R a is a straight-chain, branched or cyclic hydrocarbon group independently selected from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups and one or more combinations thereof; wherein the hydrocarbon group may be substituted or unsubstituted, may contain one or more heteroatoms and preferably has 1 to 20 carbon atoms; wherein R 4 is a straight-chain, branched or cyclic hydrocarbon group independently selected from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups and one or more combinations thereof; wherein the hydrocarbon group may be substituted or unsubstituted, may contain one or more heteroatoms and preferably has 1 to 20 carbon atoms, preferably R 4 is butyl; wherein X 4 and X 1 are each independently selected from the group consisting of fluoride ion (F-), chloride ion (Cl-), bromide ion (Br-) or iodide ion (I-), preferably chloride ion; z is in the range greater than 0 and less than 2, i.e., 0 < z < 2, and x is an integer from 0 to 2; b. Optionally, the solid Mg(OR) obtained in step i) a ) x X 1 2-x and an activated electron donor selected from the group consisting of 1 (OR b ) v-w (OR 3 ) w or M 2 (OR b ) v-w (R 3 ) w to obtain a second intermediate product; wherein: M 1 is a metal selected from the group consisting of Ti, Zr, Hf, Al or Si; v is M 1 The valence of 2 is metal Si; v is M 2 The valence of b and R 3 Each is a straight chain, branched or cyclic hydrocarbon group independently selected from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups and one or more combinations thereof; wherein the hydrocarbon group may be substituted or unsubstituted, may contain one or more heteroatoms and preferably has 1 to 20 carbon atoms; wherein w is less than v, preferably v is 3 or 4; c. contacting the first intermediate reaction product or the second intermediate reaction product obtained in step a) or b), respectively, with a halogen-containing Ti compound and an internal electron donor.

11. The polypropylene composition according to claim 7 or 8, wherein the internal donor is 3,3-bis(methoxymethyl)-2,6-dimethylheptane, and / or wherein the activating compound is NN-dimethylbenzamide and / or wherein the cocatalyst is preferably selected from the group consisting of trimethylaluminum, triethylaluminum, triisobutylaluminum, trihexylaluminum, diisobutylaluminum hydride, trioctylaluminum, dihexylaluminum hydride and mixtures thereof.

12. The polypropylene composition according to claims 7 to 9, wherein the external donor is selected from the list comprising organosilicon compounds, silanes, alkoxysilanes, alkylsilanes, alkylalkoxysilanes and aliphatic / aromatic esters, such as dicyclopentyldimethoxysilane, di-tert-butyldimethoxysilane, methylcyclohexyldimethoxysilane, ethylcyclohexyldimethoxysilane, diphenyldimethoxysilane, diisopropyldimethoxysilane, di-n-propyldimethoxysilane, diisobutyldimethoxysilane, di-n-butyldimethoxysilane, cyclopentyltrimethoxysilane, isopropyltrimethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, ethyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, cyclopentylpyrrolidinyldimethoxysilane, bis(pyrrolidinyl)-dimethoxysilane, and mixtures thereof, preferably di(isopropyl)dimethoxysilane (DiPDMS).

13. An article comprising the polypropylene composition according to any one of the preceding claims, wherein the amount of the polypropylene composition is at least 95 wt.%, based on the article, and / or wherein the article is prepared by injection molding, and / or wherein the article is a household article, such as a vacuum cleaner housing, household chemicals and paints, or a packaging article, such as a container, a crate, a box, a battery housing, a bucket, a flower pot, a food container / packaging, an ice cream container, a thin wall packaging, a lid and a closure, a healthcare packaging, or a healthcare article, such as a drug delivery article, a laboratory ware, a medical device, a medical diagnostic article, or an automotive interior article, such as a dashboard tray, a door panel, an instrument panel, a dashboard tray, a door covering, a door fixture, an armrest, a pillar covering, a seat covering, a trunk covering, an interior trim, and applications in heating, ventilation, and air conditioning (HVAC) applications.

14. Use of the polypropylene composition according to any one of claims 1 to 10 for preparing an article, wherein the amount of the polypropylene composition is at least 95 wt.%, based on the article, and / or wherein the article is prepared by injection molding, and / or wherein the article is a household article, such as a vacuum cleaner housing, household chemicals and paints, or a packaging article, such as a container, a crate, a box, a battery housing, a bucket, a flower pot, a food container / packaging, an ice cream container, a thin wall packaging, a lid and a closure, a healthcare packaging, or a healthcare article, such as a drug delivery article, a laboratory ware, a medical device, a medical diagnostic article, or an automotive interior article, such as a dashboard tray, a door panel, an instrument panel, a dashboard tray, a door covering, a door fixture, an armrest, a pillar covering, a seat covering, a trunk covering, an interior trim, and applications in heating, ventilation, and air conditioning (HVAC) applications.

15. A method for preparing an article, the method comprising the following steps a. providing a polypropylene composition as described in any one of claims 1-10, and b. converting the polypropylene composition into an article, for example by using extrusion or injection molding processes.

16. A method for preparing a polypropylene composition according to any one of claims 1 to 10, comprising i) polymerizing propylene in the presence of a catalyst to obtain a propylene homopolymer-based matrix, and ii) subsequently polymerizing ethylene with propylene in the presence of a catalyst in a propylene homopolymer matrix to obtain said heterophasic propylene copolymer, wherein steps i) and ii) are carried out in different reactors, The catalyst used in step i) and in the second step ii) comprises a) a Ziegler-Natta procatalyst comprising a compound of a transition metal of Group 4 to 6 of IUPAC, a Group 2 metal compound and an internal donor, wherein the internal donor is preferably a non-phthalic compound, more preferably a non-phthalate ester, even more preferably wherein the internal donor is selected from, for example, 3,3-bis(methoxymethyl)-2,6-dimethylheptane, 9,9-bis(methoxymethyl)fluorene, optionally substituted malonates, maleates, succinates, glutarates, benzoates, cyclohexene-1,2-dicarboxylates, benzoates, citraconates, aminobenzoates, silyl esters and derivatives and / or mixtures thereof; b) a promoter (Co), and c) Optional external donor.

17. The method according to claim 14, wherein the Ziegler-Natta procatalyst is prepared according to the following steps: a. Make compound R 4 z MgX 4 2-z contacting with an alkoxy- or aryloxy-containing silane compound to produce a first intermediate reaction product, namely solid Mg(OR a ) x X 1 2-x ,in: R a is a straight chain, branched or cyclic hydrocarbon group independently selected from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups and one or more combinations thereof; wherein the hydrocarbon group may be substituted or unsubstituted, may contain one or more heteroatoms and preferably has 1 to 20 carbon atoms; wherein R 4 is a straight chain, branched or cyclic hydrocarbon group independently selected from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups and one or more combinations thereof; wherein the hydrocarbon group may be substituted or unsubstituted, may contain one or more heteroatoms and preferably has 1 to 20 carbon atoms, preferably R 4 is butyl; wherein X 4 and X 1 Each is independently selected from the group consisting of fluoride ion (F-), chloride ion (Cl-), bromide ion (Br-) or iodide ion (I-), preferably chloride ion; z is in the range of greater than 0 and less than 2, i.e. 0 <z<2; b. Optionally, the solid Mg(OR) obtained in step i) a ) x X 1 2-x and an activated electron donor selected from the group consisting of 1 (OR b ) v-w (OR 3 ) w or M 2 (OR b ) v-w (R 3 ) w to obtain a second intermediate product; wherein: M 1 is a metal selected from the group consisting of Ti, Zr, Hf, Al or Si; v is M 1 The valence of 2 is metal Si; v is M 2 The valence of b and R 3 Each is a straight chain, branched or cyclic hydrocarbon group independently selected from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups and one or more combinations thereof; wherein the hydrocarbon group may be substituted or unsubstituted, may contain one or more heteroatoms and preferably has 1 to 20 carbon atoms; wherein w is less than v, preferably v is 3 or 4; c. contacting the first intermediate reaction product or the second intermediate reaction product obtained in step a) or b), respectively, with a halogen-containing Ti compound and an internal electron donor.

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