Composition for exterior parts of automobiles

Abstract

A composition for an exterior part of an automobile, the composition comprising a) from 30 wt.-% to 45 wt.-%, based on the total weight of the composition, of a first heterophasic propylene copolymer (HECO1) having a melt flow rate MFR2 from 50 g / 10 min to 250 g / 10 min as determined according to ISO 1133 at 230 DEG C and a load of 2.16 kg, as determined according to the CRYSTEX method, and a second heterophasic propylene copolymer (HECO1) having a melt flow rate MFR2 from 50 g / 10 min to 250 g / 10 min as determined according to the CRYSTEX method. A soluble component (SF) content of from 6 wt.-% to 22 wt.-%, based on the total weight of the first heterophasic propylene copolymer (HECO1), and an ethylene content C2 (SF) of from 15 wt.-% to 30 wt.-%, based on the total weight of soluble components (SF) of the heterophasic propylene copolymer (HECO1), as determined by Fourier transform infrared spectroscopy (FTIR) calibrated with 13C-NMR spectroscopy, b) from 15 wt.-% to 30 wt.-%, based on the total weight of the composition, of a second heterophasic propylene copolymer (HECO2) having an MFR2 from 5 g / 10 min to 15 g / 10 min as determined according to ISO 1133 at 230 DEG C and under a load of 2.16 kg, a soluble component (SF) content from 25 wt.-% to 45 wt.-%, based on the second heterophasic propylene copolymer (HECO2), as determined according to the CRYSTEX method, and an ethylene content C2 (SF) of from 30 wt.-% to 50 wt.-%, based on the total weight of the soluble components (SF) of the heterophasic propylene copolymer (HECO2), as determined by Fourier transform infrared spectroscopy (FTIR) calibrated with 13C-NMR spectroscopy, c) from 8 wt.-% to 18 wt.-%, based on the total weight of the composition, of an ethylene copolymer having a density of from 860 kg / m3 to 880 kg / m3, as determined according to ISO 1183, and an MFR2 of from 0.1 g / 10 min to 3.0 g / 10 min as determined according to ISO 1133 at 190 DEG C and a load of 2.16 kg, and d) from 15 wt.-% to 30 wt.-%, based on the total weight of the composition, of an inorganic filler.

Description

Technical Field

[0001] The present invention relates to a composition for automotive exterior components, an article comprising the composition, and the use of the composition for improving paint adhesion. Background Art

[0002] In the field of automotive applications, polyolefins (such as polypropylene) are the preferred materials because they can be customized to meet specific requirements. For example, heterophasic polypropylene is widely used in the automotive industry due to its good stiffness and reasonable impact strength, such as in bumper applications.

[0003] However, the surface of molded articles obtained from heterophasic polypropylene compositions is quite smooth and has low polarity, resulting in unfavorable preconditions for the interaction with coating materials. Therefore, for high-demanding applications such as automotive components, especially automotive exterior components, pretreatment and application of an adhesion promoter (primer) are usually required to ensure proper paint adhesion. However, due to environmental and economic reasons, it is desirable to minimize the use of primers, preferably avoid using primers altogether.

[0004] EP 3 336 109 A1 discloses a polypropylene composition having excellent paint adhesion and a molded article comprising the composition. The polypropylene composition comprises a first multiphase propylene copolymer as the main part, with a content of 62 wt.-% to 85 wt.-% based on the total weight of the polypropylene composition, and also comprises a second multiphase propylene copolymer and an inorganic filler. However, for certain applications, the corresponding composition is insufficient in terms of stiffness.

[0005] WO 2014 / 191211 A1 relates to a rigid polypropylene composition suitable for primerless coatings. It provides a polypropylene composition comprising a multiphase propylene copolymer having an MFR 2 (230 °C, 2.16 kg) of 10 g / 10 min to 40 g / 10 min, 5 wt.-% to 70 wt.-% of a polypropylene homopolymer, and 20 wt.-% to 40 wt.-% of a filler. However, for certain applications, the corresponding composition has insufficient impact strength. Summary of the Invention

[0006] Therefore, the object of the present invention is to provide a composition that enables a person skilled in the art to produce articles, such as molded articles or injection-molded articles, having good stiffness, good impact strength, and good paint adhesion simultaneously, without the need to apply an adhesion promoter such as a primer.

[0007] Now, it has surprisingly been found that the above object can be achieved by providing a composition, preferably a polypropylene composition, preferably a composition for automotive exterior parts, which composition comprises the following components, or consists of the following components:

[0008] a) A first multiphase propylene copolymer (HECO1) in an amount of 30 wt.-% to 45 wt.-% based on the total weight of the composition, which first multiphase propylene copolymer has

[0009] a melt flow rate MFR as determined according to ISO 1133 at 230 °C and a load of 2.16 kg of 70 g / 10 min to 250 g / 10 min 2 ,

[0010] a soluble fraction (SF) content of 6 wt.-% to 22 wt.-% based on the total weight of the first multiphase propylene copolymer (HECO1) as determined according to the CRYSTEX method, and

[0011] an ethylene content C2(SF) of 15 wt.-% to 30 wt.-% based on the total weight of the soluble fraction (SF) of the multiphase propylene copolymer (HECO1) as determined by Fourier transform infrared spectroscopy (FTIR) calibrated with 13 13C-NMR spectroscopy,

[0012] b) A second multiphase propylene copolymer (HECO2) in an amount of 15 wt.-% to 30 wt.-% based on the total weight of the composition, which second multiphase propylene copolymer has

[0013] an MFR as determined according to ISO 1133 at 230 °C and a load of 2.16 kg of 5 g / 10 min to 15 g / 10 min 2 ,

[0014] a soluble fraction (SF) content of 25 wt.-% to 45 wt.-% based on the second multiphase propylene copolymer (HECO2) as determined according to the CRYSTEX method, and

[0015] an ethylene content C2(SF) of 30 wt.-% to 50 wt.-% based on the total weight of the soluble fraction (SF) of the multiphase propylene copolymer (HECO2) as determined by Fourier transform infrared spectroscopy (FTIR) calibrated with 13 13C-NMR spectroscopy,

[0016] c) An ethylene copolymer in an amount of 8 wt.-% to 18 wt.-% based on the total weight of the composition, which ethylene copolymer has

[0017] a density as determined according to ISO 1183 of 860 kg / m3 to 880 kg / m 3 a density, and

[0018] an MFR as determined according to ISO 1133 at 190 °C and a load of 2.16 kg of from 0.1 g / 10 min to 3.0 g / 10 min 2 ,

[0019] d) an inorganic filler based on 15 wt.-% to 30 wt.-% of the total weight of the composition,

[0020] wherein, as determined according to ISO 1133 at 230 °C and a load of 2.16 kg, the composition has an MFR of from 15 g / 10 min to 30 g / 10 min 2 .

[0021] The present invention is based on a surprising finding that the use of a specific first multiphase propylene copolymer as described herein in a composition can result in a surprising balance between improved paint adhesion, stiffness and impact strength.

[0022] The present invention offers many advantages. The polypropylene-based composition according to the present invention for use in exterior and interior parts of the automotive industry enables weight reduction and design freedom not only at an overall acceptable cost level. In addition, the coatability or paint adhesion of parts formed from the composition according to the present invention is significantly improved when using the latest two-layer primerless paint systems, which is particularly useful for automotive exterior parts.

[0023] As used herein, the expression "homopolymer" refers to polypropylene consisting essentially of propylene units, i.e., polypropylene consisting of at least 99.5 wt.-%, preferably at least 99.7 wt.-%, more preferably at least 99.8 wt.-% of propylene units. In a preferred embodiment, only propylene units are detectable in the propylene homopolymer.

[0024] The "peakedness" of a polymer refers to the form of its molecular weight distribution curve, i.e., the curve shape representing the polymer weight fraction as a function of its molecular weight. If a polymer is produced in a continuous step process using reactors connected in series and different conditions in each reactor, then the different components produced in the different reactors will each have their own molecular weight distribution. When the molecular weight distribution curves of these components are superimposed on the molecular weight distribution curve of the total resulting polymer product, the curve will show two or more maxima, or at least be significantly broader compared to the curve of a single component. Such a polymer product produced in two or more consecutive steps is called bimodal or multimodal depending on the number of steps. Hereinafter, all polymers produced in two or more consecutive steps are referred to as "multimodal". It should be noted that the chemical composition of the different components may also be different.

[0025] Composition

[0026] The composition has a moderate melt flow rate MFR 2 . Determined according to ISO 1133 at 230 °C and a load of 2.16 kg, the composition has an MFR2 of 15 g / 10 min to 30 g / 10 min, preferably 18 g / 10 min to 28 g / 10 min.

[0027] Preferably, determined according to ISO 178 on injection molded specimens, the composition has a flexural modulus in the range of 1750 MPa to 2750 MPa, more preferably in the range of 1800 MPa to 2600 MPa.

[0028] Preferably, determined according to ISO 179 / eA on injection molded specimens, the composition has a Charpy notched impact strength (NIS) at 23 °C in the range of 30 kJ / m 2 to 85 kJ / m 2 range, more preferably in the range of 35 kJ / m 2 to 75 kJ / m 2 .

[0029] The composition comprises two different heterophasic propylene copolymers (HECO), namely a first heterophasic propylene polymer (HECO1) as component a) and a second heterophasic propylene copolymer (HECO2) as component b).

[0030] First heterophasic propylene polymer (HECO1)

[0031] Based on the total weight of the composition, the first heterophasic propylene copolymer (HECO1) is present in an amount of 30 wt.-% to 45 wt.-%, preferably 33 wt.-% to 42 wt.-%, more preferably 35 wt.-% to 40 wt.-%.

[0032] Determined according to ISO 1133 at 230 °C and a load of 2.16 kg, the first heterophasic propylene copolymer (HECO1) has a melt flow rate MFR of 70 g / 10 min to 250 g / 10 min 2 , preferably 70 g / 10 min to 200 g / 10 min, preferably 75 g / 10 min to 150 g / 10 min, more preferably 80 g / 10 min to 120 g / 10 min.

[0033] As determined by the CRYSTEX method, based on the total weight of the first multiphase propylene copolymer (HECO1), the first multiphase propylene copolymer (HECO1) has a soluble fraction (SF) content of 6 wt.-% to 22 wt.-%, preferably 7 wt.-% to 20 wt.-%, more preferably 8 wt.-% to 18 wt.-%. Correspondingly, as determined by the CRYSTEX method, based on the total weight of the first multiphase propylene copolymer (HECO1), the first multiphase propylene copolymer (HECO1) has a crystalline fraction (CF) content of 78 wt.-% to 94 wt.-%, preferably 80 wt.-% to 93 wt.-%, and more preferably 82 wt.-% to 92 wt.-%.

[0034] As determined by Fourier Transform Infrared Spectroscopy (FTIR) calibrated with 13 C-NMR spectroscopy, based on the total weight of the soluble fraction (SF) of the multiphase propylene copolymer (HECO1), the first multiphase propylene copolymer (HECO1) has an ethylene content C2(SF) of 15 wt.-% to 30 wt.-%, preferably 18 wt.-% to 28 wt.-%, more preferably 20 wt.-% to 26 wt.-%,

[0035] Preferably, as determined by differential scanning calorimetry (DSC) according to ISO 11357, the first multiphase propylene copolymer (HECO1) has a melting temperature Tm in the range of 145 °C to 160 °C, more preferably in the range of 148 °C to 158 °C, and / or

[0036] As determined in decalin according to ISO 1628-3, the intrinsic viscosity of the soluble fraction (IV(SF)) is preferably 2.2 dl / g to 3.2 dl / g.

[0037] Preferably, as determined in decalin according to ISO 1628-3, the ratio of the intrinsic viscosity of the soluble fraction (IV(SF)) to the intrinsic viscosity of the crystalline fraction (IV(CF)) of the first multiphase propylene copolymer (HECO1), (IV(SF)) / (IV(CF)), is greater than 1.8 to 4.0, more preferably 2.2 to 2.5.

[0038] Based on the total weight of the first multiphase propylene copolymer (CHCO1), the content of the component soluble in cold xylene at 25 °C (XCS component) in the first multiphase propylene copolymer (HECO1) is preferably in the range of 6 wt.-% to 22 wt.-%, more preferably in the range of 7 wt.-% to 20 wt.-%, and most preferably in the range of 8 wt.-% to 18 wt.-%, and / or

[0039] As determined by Fourier transform infrared spectroscopy (FTIR) calibrated with 13 C-NMR spectroscopy, based on the total weight of the first multiphase propylene copolymer (HECO1), the first multiphase propylene copolymer (HECO1) has a total ethylene content (total C2) preferably in the range of 1.8 wt.-% to 6.5 wt.-%, more preferably in the range of 1.9 wt.-% to 6.0 wt.-%, and most preferably in the range of 2.0 wt.-% to 5.5 wt.-%.

[0040] Preferably, as determined in decalin according to ISO 1628-3, the fraction soluble in cold xylene (XCS fraction) of the first multiphase propylene copolymer (HECO1) at 25 °C has an intrinsic viscosity (IV(XCS)) of 1.8 dl / g to 3.2 dl / g, preferably 2.0 dl / g to 3.0 dl / g, and most preferably 2.2 dl / g to 2.8 dl / g.

[0041] The first multiphase propylene copolymer (HECO1) comprises a matrix phase (A) and a dispersed phase (B) dispersed in the matrix phase (A), or consists of a matrix phase (A) and a dispersed phase (B) dispersed in the matrix phase (A).

[0042] Matrix phase (A)

[0043] The matrix phase (A) can be unimodal or multimodal, for example bimodal. The matrix phase (A) preferably comprises a propylene copolymer or a propylene homopolymer, or consists of a propylene copolymer or a propylene homopolymer. More preferably, the matrix phase (A) comprises a propylene homopolymer, or consists of a propylene homopolymer.

[0044] Preferably, the matrix phase (A) of the first multiphase propylene copolymer (HECO1) is bimodal, more preferably the matrix phase (A) of the first heterophasic propylene copolymer (HECO1) is bimodal, and comprises a first propylene polymer component and a second propylene polymer component, or consists of a first propylene polymer component and a second propylene polymer component.

[0045] As determined according to ISO 1133 at 230 °C and a load of 2.16 kg, the matrix phase (A) of the first multiphase propylene copolymer (HECO1) (preferably the bimodal matrix phase (A)) has a melt flow rate MFR preferably of 100 g / 10 min to 500 g / 10 min 2 , more preferably 120 g / 10 min to 400 g / 10 min, even more preferably 140 g / 10 min to 200 g / 10 min.

[0046] Based on the total weight of the matrix phase (A) of the first multiphase propylene copolymer (HECO1), the matrix phase (A) of the first heterophasic propylene copolymer (HECO1) (preferably a bimodal matrix phase (A)) contains a component (XCS component) soluble in cold xylene at 25°C, and the content is preferably in the range of greater than 0 wt.-% to less than 2.0 wt.-%, more preferably in the range of 0.30 wt.-% to 1.80 wt.-%.

[0047] Dispersed phase (B)

[0048] The dispersed phase (B) comprises or consists of a copolymer of propylene and a comonomer, and the comonomer is selected from α-olefins having 2 or 4 to 12 carbon atoms as the comonomer, preferably α-olefins having 2 or 4 to 10 carbon atoms as the comonomer, more preferably ethylene, 1-butene and / or 1-hexene, even more preferably ethylene and / or 1-butene, and most preferably ethylene as the comonomer. Therefore, most preferably the dispersed phase (B) comprises or consists of a copolymer of propylene and ethylene. Such a copolymer of propylene and ethylene is also referred to as ethylene-propylene rubber (EPR).

[0049] Preferably, based on the total amount of the dispersed phase (B), the dispersed phase (B) contains comonomer units in an amount of at most 60 mol-%, preferably in the range of 35 mol-% to 60 mol-%, more preferably in the range of 45 mol-% to 55 mol-%.

[0050] Preparation of HECO1

[0051] The first multiphase propylene copolymer (HECO1) is preferably produced in a multi-stage process. Preferably, the first multiphase propylene copolymer (HECO1) comprising the matrix phase (A) and the dispersed phase (B) dispersed in the matrix phase (A) or consisting of the matrix phase (A) and the dispersed phase (B) dispersed in the matrix phase (A) is obtained by a method comprising the following steps:

[0052] a) Preparing the matrix phase (A) of the first multiphase propylene copolymer by the following:

[0053] a1) Polymerizing propylene in a first reactor to obtain a first propylene polymer component,

[0054] a2) Transferring the first propylene polymer component to a second reactor and polymerizing propylene in the second reactor to obtain a second propylene polymer component,

[0055] b) Preparing the dispersed phase (B) of the first multiphase propylene copolymer by the following:

[0056] b1) Transfer the first propylene polymer component and the second propylene polymer component to a third reactor, and polymerize propylene and an α-olefin having 2 or 4 to 10 carbon atoms (preferably an α-olefin having 2 carbon atoms) in the third reactor to obtain a third propylene polymer component.

[0057] Among them, the polymerizations in steps a1), a2) and b1) are carried out in the presence of a metallocene catalyst system as described below.

[0058] The first reactor is preferably a slurry-phase reactor, such as a loop reactor. Preferably, the operating temperature in the first reactor (preferably the loop reactor) is in the range of 62°C to 85°C, more preferably in the range of 65°C to 82°C, and still more preferably in the range of 67°C to 80°C.

[0059] Generally, the pressure in the first reactor (preferably the loop reactor) is in the range of 20 bar to 80 bar, preferably 30 bar to 70 bar, such as 35 bar to 65 bar.

[0060] Preferably, a propylene homopolymer is produced in the first reactor (preferably the loop reactor). Therefore, preferably, the first propylene polymer component is a propylene homopolymer component.

[0061] Preferably, hydrogen is added in the first reactor to control the molecular weight, i.e., the melt flow rate MFR. 2 . Preferably, in step a1), the ratio of hydrogen feed to propylene feed is 0.1 mol / kmol to 0.5 mol / kmol, preferably 0.15 mol / kmol to 0.45 mol / kmol, and most preferably 0.2 mol / kmol to 0.4 mol / kmol.

[0062] The average residence time in the first reactor (preferably the loop reactor) is generally 15 min to 120 min, preferably 20 min to 80 min. As is well known in the art, the average residence time τ can be calculated by the following equation (1):

[0063]

[0064] Where

[0065] V R is the volume of the reaction space (for a loop reactor, it is the volume of the reactor; for a fluidized bed reactor, it is the volume of the fluidized bed).

[0066] Q o is the volumetric flow rate of the product stream (including the polymer product and the fluid reaction mixture).

[0067] The production rate is appropriately controlled by the catalyst feed rate and temperature. The production rate can also be affected by appropriately selecting the monomer concentration. Then, the desired monomer concentration can be achieved by appropriately adjusting the propylene feed rate.

[0068] The second reactor is preferably a first gas-phase reactor, such as a first fluidized-bed gas-phase reactor. Preferably, the operating temperature in the second reactor (preferably the first gas-phase reactor) is in the range of 75 °C to 95 °C, more preferably in the range of 78 °C to 92 °C. Preferably, the pressure in the second reactor (preferably in the first gas-phase reactor) is in the range of 5 bar to 50 bar, preferably 15 bar to 40 bar.

[0069] The average residence time in the second reactor (preferably the first gas-phase reactor) is generally 30 min to 130 min. Refer to Equation (1) above.

[0070] Preferably, a propylene homopolymer is produced in the second reactor (preferably the first gas-phase reactor). Thus, preferably, the second propylene polymer component is a propylene homopolymer component.

[0071] Preferably, hydrogen is added to the second reactor to control the molecular weight, i.e., the melt flow rate MFR 2 . Preferably, the ratio of hydrogen to propylene (H2 / C3 ratio) in the second reactor (preferably the first gas-phase reactor) is in the range of 2.0 mol / kmol to 8.5 mol / kmol, more preferably 3.0 mol / kmol to 7.5 mol / kmol.

[0072] The third reactor is preferably a second gas-phase reactor, such as a second fluidized-bed gas-phase reactor. Preferably, the operating temperature in the third reactor (preferably the second gas-phase reactor) is in the range of 65 °C to 85 °C, more preferably in the range of 68 °C to 82 °C. Generally, the operating temperature in the third reactor is lower than that in the second reactor. Generally, the pressure in the third reactor (preferably the second gas-phase reactor) is in the range of 5 bar to 50 bar, preferably 15 bar to 40 bar.

[0073] The average residence time in the third reactor (preferably the second gas-phase reactor) is generally 30 min to 130 min. Refer to Equation (1) above.

[0074] In the third reactor (preferably the second gas-phase reactor), the dispersed phase (B) of the first multiphase propylene copolymer (HECO1) is produced, i.e., a copolymer of propylene and an α-olefin selected from those having 2 or 4 to 12 carbon atoms as a comonomer is produced, preferably an α-olefin having 2 or 4 to 10 carbon atoms, more preferably ethylene, 1-butene and / or 1-hexene, even more preferably ethylene and / or 1-butene and most preferably ethylene as a comonomer. Preferably, in the third reactor (preferably the second gas-phase reactor), a propylene-ethylene copolymer is produced. Accordingly, the third propylene polymer component is a propylene-ethylene copolymer component.

[0075] The ratio of ethylene to propylene (C2 / C3 ratio) in the third reactor (preferably the second gas-phase reactor) is in the range of 700 mol / kmol to 1000 mol / kmol, more preferably 800 mol / kmol to 950 mol / kmol.

[0076] Preferably, the ratio of hydrogen to ethylene (H2 / C2 ratio) in the third reactor (preferably the second gas-phase reactor) is in the range of 0.5 mol / kmol to 3.5 mol / kmol, more preferably 1.0 mol / kmol to 2.5 mol / kmol.

[0077] The combined first propylene polymer component, second propylene polymer component and third propylene polymer component preferably form the first multiphase propylene copolymer (HECO1).

[0078] A preferred multistage process is the slurry-gas phase process defined above, for example the process developed by Borealis and known as technology. In this regard, see EP applications EP 0 887 379 A1 and EP 0517 868 A1.

[0079] In addition to the (main) polymerization stages in at least three reactors, the preparation of the first propylene polymer component, second propylene polymer component and third propylene polymer component may further include prepolymerization in a prepolymerization reactor upstream of the first reactor before them.

[0080] In the pre-polymerization reactor, polypropylene is produced. The pre-polymerization is carried out in the presence of a metallocene catalyst system. However, this does not exclude the option of adding other co-catalysts at a subsequent stage (e.g., in the first reactor) during the polymerization process, for example. In one embodiment, if pre-polymerization is carried out, all components of the metallocene catalyst system are added only to the pre-polymerization reactor. The pre-polymerization reaction is typically carried out at a temperature of 0 °C to 60 °C, preferably 15 °C to 50 °C, and more preferably 20 °C to 45 °C. The pressure in the pre-polymerization reactor is not critical, but must be high enough to keep the reaction mixture in the liquid phase. Thus, the pressure can be 20 to 100 bar, for example 30 bar to 70 bar. The average residence time in the pre-polymerization reactor is typically 15 min to 45 min. Refer to Equation (1) above.

[0081] In a preferred embodiment, the pre-polymerization is carried out in the form of bulk slurry polymerization in liquid propylene, i.e., the liquid phase mainly comprises propylene, in which optional inert components are dissolved.

[0082] Other components can also be added to the pre-polymerization stage. Thus, as is known in the art, hydrogen can be added in the pre-polymerization stage to control the molecular weight of the polypropylene. Precise control of the pre-polymerization conditions and reaction parameters belongs to the conventional technical means in the art.

[0083] Due to the above-specified process conditions in the pre-polymerization, a mixture of the metallocene catalyst system and the polypropylene produced in the pre-polymerization reactor is preferably obtained. Preferably, the metallocene catalyst system is (finely) dispersed in the polypropylene. In other words, the metallocene catalyst particles introduced into the pre-polymerization reactor are broken into smaller fragments, which are evenly distributed in the growing polypropylene. The size of the introduced metallocene catalyst particles and the resulting fragments is not of fundamental relevance to the present invention and is well known to those skilled in the art.

[0084] As described above, if pre-polymerization is used, after the pre-polymerization, the mixture of the metallocene catalyst system and the polypropylene produced in the pre-polymerization reactor is transferred to the first reactor. Generally, the total amount of polypropylene produced in the pre-polymerization reactor is quite low in the first propylene polymer component, the second propylene polymer component, and the third propylene polymer component, usually not exceeding 5.0 wt.-%, more preferably not exceeding 4.0 wt.-%, still more preferably in the range of 0.1 wt.-% to 4.0 wt.-%, such as in the range of 0.5 wt.-% to 3.0 wt.-%.

[0085] In the case of not using pre-polymerization, propylene and other components (such as the metallocene catalyst system) are directly introduced into the first reactor.

[0086] Metallocene catalyst system

[0087] The first multiphase propylene copolymer (HECO1) is prepared in the presence of at least one metallocene catalyst system.

[0088] The metallocene catalyst system can be any supported metallocene catalyst system suitable for the production of multiphase propylene copolymers.

[0089] Preferably, the metallocene catalyst system comprises (i) a metallocene complex, (ii) a cocatalyst system comprising a boron-containing cocatalyst and / or an aluminoxane cocatalyst, and (iii) a support, preferably a support comprising or consisting of silica.

[0090] Preferably, the metallocene catalyst system comprises

[0091] (i) a metallocene complex of formula (I):

[0092]

[0093] wherein each X is independently a σ-donor ligand,

[0094] L is a divalent bridge selected from -R' 2 C-, -R' 2 C-CR' 2 -, -R' 2 Si-, -R' 2 Si-SiR' 2 -, and -R' 2 Ge-, wherein each R' is independently a hydrogen atom or a C 1 -C 20 hydrocarbyl optionally containing one or more heteroatoms from Groups 14-16 of the Periodic Table or fluorine atoms, or optionally two R' groups may combine together to form a ring,

[0095] each R 1 is independently the same or different and is hydrogen, a straight-chain or branched C 1 -C 6 alkyl, C 7-20 arylalkyl, C 7-20 alkylaryl or C 6-20 aryl or an OY group, wherein Y is a C 1-10 hydrocarbyl, and optionally two adjacent R 1 groups may be part of a ring including the phenyl carbon to which they are bonded,

[0096] each R 2 is independently the same or different and is CH 2 -R8 group, where R 8 is H or a straight-chain or branched C 1 -C 6 alkyl, C 3-8 cycloalkyl or C 6-10 aryl;

[0097] R 3 is a straight-chain or branched C 1 -C 6 alkyl, C 7-20 arylalkyl, C 7-20 alkylaryl or C 6 -C 20 aryl;

[0098] R 4 is a C(R 9 ) 3 group, where R 9 is a straight-chain or branched C 1 -C 6 alkyl;

[0099] R 5 is hydrogen or an aliphatic C 1 -C 20 hydrocarbyl optionally containing one or more heteroatoms from Groups 14 - 16 of the Periodic Table;

[0100] R 6 is hydrogen or an aliphatic C 1 -C 20 hydrocarbyl optionally containing one or more heteroatoms from Groups 14 - 16 of the Periodic Table; or

[0101] R 5 and R 6 can combine together to form a 5 - membered saturated carbocyclic ring optionally substituted by n groups R 10 where n is from 0 to 4;

[0102] Each R 10 is the same or different and can be a C 1 -C 20 hydrocarbyl or a C 1 -C 20 hydrocarbyl optionally containing one or more heteroatoms belonging to Groups 14 - 16 of the Periodic Table;

[0103] R 7 is H or a straight-chain or branched C 1 -C 6 alkyl, or an aryl or heteroaryl having 6 to 20 carbon atoms, said aryl or heteroaryl being optionally substituted by 1 to 3 groups R 11 ;

[0104] Each R 11 is independently the same or different and is hydrogen, a straight-chain or branched C 1 -C 6 alkyl, C 7-20 arylalkyl, C 7-20 alkylaryl or C 6-20 aryl or an OY group, where Y is a C 1-10 hydrocarbyl group.

[0105] (ii) a cocatalyst system comprising a boron-containing cocatalyst and / or an aluminoxane cocatalyst, and

[0106] (iii) a support, preferably a support comprising and consisting of silica.

[0107] The term "σ-donor ligand" is well known to those skilled in the art and is a group that binds to a metal through a σ bond. Thus, the anionic ligand "X" can independently be a halogen or selected from R', OR', SiR' 3 , OSiR' 3 , OSO 2 CF 3 , OCOR', SR', NR' 2 or PR' 2 groups, where R' is independently hydrogen, a straight-chain or branched, cyclic or acyclic C 1 to C 20 alkyl, C 2 to C 20 alkenyl, C 2 to C 20 alkynyl, C 3 to C 12 cycloalkyl, C 6 to C 20 aryl, C 7 to C 20 arylalkyl, C 7 to C 20 alkylaryl, C 8 to C 20 arylalkenyl, where the R' groups may optionally contain one or more heteroatoms belonging to Groups 14 to 16. In a preferred embodiment, the anionic ligand "X" is the same and is either a halogen (such as Cl) or methyl or benzyl. A preferred monovalent anionic ligand is a halogen, especially chlorine (Cl).

[0108] More information, especially regarding the preparation of such catalysts, can be found in, for example, WO 2013 / 007650A1.

[0109] The preferred metallocene complex (i) of the metallocene catalyst comprises:

[0110] rac-dimethylsilanediylbis[2-methyl-4-(3’,5′-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride

[0111] rac-anti-dimethylsilanediyl[2-methyl-4-(4′-tert-butylphenyl)-inden-1-yl][2-methyl-4-(4’tertbutylphenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride

[0112] rac-anti-dimethylsilanediyl[2-methyl-4-(4′-tert-butylphenyl)-inden-1-yl][2-methyl-4-phenyl-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride

[0113] rac-anti-dimethylsilanediyl[2-methyl-4-(3′,5′-tert-butylphenyl)-1,5,6,7-tetrahydro-sindacen-1-yl][2-methyl-4-(3’,5’-dimethyl-phenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride

[0114] rac-anti-dimethylsilanediyl[2-methyl-4,8-bis-(4′-tert-butylphenyl)-1,5,6,7-tetrahydro-sindacen-1-yl][2-methyl-4-(3’,5’-dimethyl-phenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride

[0115] rac-anti-dimethylsilanediyl[2-methyl-4,8-bis-(3’,5’-dimethylphenyl)-1,5,6,7-tetrahydro-s-indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride

[0116] rac-anti-dimethylsilanediyl[2-methyl-4,8-bis-(3’,5’-dimethylphenyl)-1,5,6,7-tetrah ydro-s-indacen-1-yl][2-methyl-4-(3’,5’-5-ditert-butyl-phenyl)-5-methoxy-6-tert-butyl inden-1-yl]zirconium dichloride,

[0117] or their corresponding dimethylzirconium analogues.

[0118] Particularly preferred is rac-anti-dimethylsilanediyl[2-methyl-4,8-bis-(3’,5’-dimethylphenyl)-1,5,6,7-tetrah ydro-s-indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butyl inden-1-yl]zirconium dichloride.

[0119] Also particularly preferred is that the metallocene catalyst system comprises a metallocene complex (i) of formula (II):

[0120]

[0121] wherein each R 1 is independently the same or different and is hydrogen or a straight-chain or branched C 1 -C 6 alkyl group, with at least one of the Rs on each phenyl group not being hydrogen, 1 Rˊ is a C

[0122] -C 1 -C 10 hydrocarbyl group, preferably a C 1 -C 4 hydrocarbyl group, and more preferably methyl, and X is independently a hydrogen atom, a halogen atom, a C 1 -C 6 alkoxy group, a C 1 -C 6 alkyl group, a phenyl group or a benzyl group.

[0123] Most preferably, X is chlorine, benzyl or methyl. Preferably, the two X groups are the same. The most preferred options are two chlorines, two methyls or two benzyls, especially two chlorines.

[0124] Particularly preferred is the racemic-trans-dimethylsilanediyl[2-methyl-4,8-bis(3',5'-dimethylphenyl)-1,5,6,7-tetrahydro-s-dicyclopentadienylphenyl-1-yl][2-methyl-4-(3',5'-dimethylphenyl)-5-methoxy-6-tert-butylindene-1-yl]zirconium dichloride of formula (III):

[0125]

[0126] The ligands required to form the complex and thus the catalysts of the present invention can be synthesized by any method, and a skilled organic chemist will be able to design various synthetic schemes for manufacturing the necessary ligand materials. For example, WO 2007 / 116034 discloses the necessary chemical knowledge. Synthetic schemes can generally also be found in WO 2002 / 02576, WO 2011 / 135004, WO 2012 / 084961, WO 2012 / 001052, WO 2011 / 076780, WO 2015 / 158790 and WO 2018 / 122134. In particular, reference is made to WO 2019 / 179959, which describes the most preferred catalysts of the present invention.

[0127] Cocatalyst system

[0128] To form the active catalytic species, cocatalysts well known in the art are generally required. A cocatalyst system (ii) comprising a boron-containing cocatalyst and / or an aluminoxane cocatalyst is used in combination with the metallocene complex (i) defined above.

[0129] The aluminoxane cocatalyst can be one of those of formula (IV):

[0130]

[0131] wherein n is generally from 6 to 20, and R has the following meanings.

[0132] Aluminoxane is formed upon partial hydrolysis of an organoaluminum compound, such as those of the general formula AlR 3 、AlR 2 Y and Al 2 R 3 Y 3 wherein R can be, for example, C 1 -C 10 alkyl (preferably C 1 -C 5 alkyl), or C3 -C 10 cycloalkyl, C 7 -C 12 arylalkyl or alkylaryl and / or phenyl or naphthyl of, and wherein Y may be hydrogen, halogen (preferably chlorine or bromine) or C 1 -C 10 alkoxy (preferably methoxy or ethoxy). The resulting oxygen-containing aluminoxane is generally not a pure compound, but a mixture of oligomers of formula (IV).

[0133] The preferred aluminoxane is methylaluminoxane (MAO). Since the aluminoxane used as a cocatalyst according to the present invention is not a pure compound due to its preparation method, the molar concentration of the aluminoxane solution hereinafter is based on their aluminum content.

[0134] In addition, a boron-containing cocatalyst can be used instead of the aluminoxane cocatalyst, or the aluminoxane cocatalyst can be used in combination with a boron-containing cocatalyst.

[0135] Those skilled in the art will understand that in the case of using a boron-based cocatalyst, it is usually prealkylated by the reaction of the complex with an alkylaluminum compound (such as TIBA). This procedure is well known and any suitable alkylaluminum can be used, such as Al(C 1 -C 6 alkyl) 3 . The preferred alkylaluminum compounds are triethylaluminum, triisobutylaluminum, triisohexylaluminum, tri-n-octylaluminum and triisooctylaluminum.

[0136] Alternatively, when using a borate cocatalyst, the metallocene complex is in its alkylated form, i.e., for example, a dimethylmetallocene complex or a diphenylmethylmetallocene complex can be used.

[0137] Valuable boron-based cocatalysts include those of formula (V)

[0138] BY 3 (V)

[0139] wherein Y is the same or different and is a hydrogen atom, an alkyl group having from 1 to about 20 carbon atoms, an aryl group having from 6 to about 15 carbon atoms, an alkylaryl group, an arylalkyl group, a haloalkyl group or a haloaryl group (wherein each has from 1 to 10 carbon atoms in the alkyl group and from 6 to 20 carbon atoms in the aryl group), or fluorine, chlorine, bromine or iodine. Preferred examples of Y are methyl, propyl, isopropyl, isobutyl or trifluoromethyl, unsaturated groups such as aryl or haloaryl, for example phenyl, tolyl, benzyl, p-fluorophenyl, 3,5-difluorophenyl, pentachlorophenyl, pentafluorophenyl, 3,4,5-trifluorophenyl and 3,5-bis(trifluoromethyl)phenyl. Preferred options are borane trifluoride, triphenylborane, tris(4-fluorophenyl)borane, tris(3,5-difluorophenyl)borane, tris(4-fluoromethylphenyl)borane, tris(2,4,6-trifluorophenyl)borane, tris(pentafluorophenyl)borane, tris(tolyl)borane, tris(3,5-dimethylphenyl)borane, tris(3,5-difluorophenyl)borane and / or tris(3,4,5-trifluorophenyl)borane.

[0140] Tris(pentafluorophenyl)borane is particularly preferred.

[0141] However, it is preferred to use borates, i.e., compounds containing the borate 3+ ion.

[0142] Such ionic cocatalysts preferably contain non-coordinating anions such as tetrakis(pentafluorophenyl)borate and tetraphenylborate. Suitable counterions are protonated amines or aniline derivatives such as methylammonium, anilinium, dimethylammonium, diethylammonium, N-methylanilinium, diphenylammonium, N,N-dimethylanilinium, trimethylammonium, triethylammonium, tri-n-butylammonium, methyldiphenylammonium, pyridinium, p-bromo-N,N-dimethylanilinium or p-nitro-N,N-dimethylanilinium.

[0143] Preferred ionic compounds that can be used according to the present invention include:

[0144] triethylammoniumtetra(phenyl)borate,

[0145] tributylammoniumtetra(phenyl)borate,

[0146] trimethylammoniumtetra(tolyl)borate,

[0147] tributylammoniumtetra(tolyl)borate,

[0148] tributylammonium tetra(pentafluorophenyl)borate

[0149] tripropylammonium tetra(dimethylphenyl)borate

[0150] tributylammonium tetra(trifluoromethylphenyl)borate

[0151] tributylammonium tetra(4-fluorophenyl)borate, N,N-dimethylcyclohexylammonium tetrakis(pentafluorophenyl)borate

[0152] N,N-dimethylbenzylammonium tetrakis(pentafluorophenyl)borate

[0153] N,N-dimethylanilinium tetra(phenyl)borate, N,N-diethylanilinium tetra(phenyl)borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate

[0154] N,N-di(propyl)ammonium tetrakis(pentafluorophenyl)borate

[0155] di(cyclohexyl)ammonium tetrakist(pentafluorophenyl)borate

[0156] triphenylphosphonium tetrakis(phenyl)borate,

[0157] triethylphosphonium tetrakis(phenyl)borate,

[0158] diphenylphosphonium tetrakis(phenyl)borate, tri(methylphenyl)phosphonium tetrakis(phenyl)borate,

[0159] tri(dimethylphenyl)phosphonium tetrakis(phenyl)borate,

[0160] triphenylcarbenium tetrakis(pentafluorophenyl)borate,

[0161] or ferrocenium tetrakis(pentafluorophenyl)borate.

[0162] Preferably, triphenylcarbenium tetrakis(pentafluorophenyl)borate, N,N-dimethylcyclohexylammonium tetrakis(pentafluorophenyl)borate or N,N-dimethylbenzylammonium tetrakis(pentafluorophenyl)borate.

[0163] Surprisingly, it has been found that certain boron cocatalysts are particularly preferred.

[0164] The preferred borates used in the present invention thus contain a trityl ion. Thus, the use of N,N-dimethylammonium tetrakis(pentafluorophenyl)borate and Ph 3 CB(PhF 5 ) 4 and its analogs are thus particularly preferred.

[0165] According to the present invention, the preferred cocatalyst is aluminoxane, more preferably methylaluminoxane, a combination of aluminoxane and alkylaluminum, a boron or borate cocatalyst, and a combination of aluminoxane and a boron-based cocatalyst.

[0166] A suitable amount of the cocatalyst is well known to those skilled in the art.

[0167] The molar ratio of boron to the metal ions of the metallocene can range from 0.5:1 mol / mol to 10:1 mol / mol, preferably from 1:1 mol / mol to 10:1 mol / mol, and particularly from 1:1 mol / mol to 5:1 mol / mol.

[0168] The molar ratio of Al to the metal ions of the metallocene in the aluminoxane can range from 1:1 mol / mol to 2000:1 mol / mol, preferably from 10:1 mol / mol to 1000:1 mol / mol, and more preferably from 50:1 mol / mol to 500:1 mol / mol.

[0169] The metallocene catalyst system used in the polymerization process of the present invention is used in a supported form. The carrier (iii) used comprises silica and is preferably composed of silica. In other words, the carrier is preferably a silica carrier. Those skilled in the art are aware of the steps required for supporting metallocene catalysts.

[0170] Particularly preferably, the carrier is a porous material, so that the metallocene complex can be loaded into the pores of the carrier, for example, using methods similar to those described in WO 94 / 14856 (Mobil), WO 95 / 12622 (Borealis), and WO2006 / 097497.

[0171] The average particle size of the carrier can generally be from 10 μm to 100 μm. However, it has been found that there are particular advantages if the carrier has an average particle size of from 15 μm to 80 μm, preferably from 18 μm to 50 μm.

[0172] The particle size distribution of the carrier is described below. The silica carrier preferably has a D50 of from 10 μm to 80 μm, more preferably from 18 μm to 50 μm. In addition, the silica carrier preferably has a D10 of from 5 μm to 30 μm and a D90 of from 30 μm to 90 μm.

[0173] Second multiphase propylene copolymer (HECO2)

[0174] Based on the total weight of the composition, the second heterophasic propylene copolymer (HECO2) is present in an amount of from 15 wt.-% to 30 wt.-%, preferably from 18 wt.-% to 28 wt.-%, and more preferably from 20 wt.-% to 25 wt.-%.

[0175] Determined according to ISO 1133 at 230 °C and a load of 2.16 kg, the second multiphase propylene copolymer (HECO2) has a melt flow rate MFR of from 5 g / 10 min to 15 g / 10 min 2 , preferably from 6 g / 10 min to 13 g / 10 min.

[0176] As determined according to the CRYSTEX method, based on the total weight of the second multiphase propylene copolymer (HECO2), the second multiphase propylene copolymer (HECO2) has a soluble fraction (SF) content of from 25 wt.-% to 45 wt.-%, preferably from 27 wt.-% to 40 wt.-%, more preferably from 29 wt.-% to 38 wt.-%.

[0177] As determined by Fourier transform infrared spectroscopy (FTIR) calibrated with 13 13C-NMR spectroscopy, based on the total weight of the soluble fraction (SF) of the second multiphase propylene copolymer (HECO2), the second multiphase propylene copolymer (HECO2) has an ethylene content C2(SF) of from 30 wt.-% to 50 wt.-%, preferably from 32 wt.-% to 45 wt.-%, more preferably from 35 wt.-% to 42 wt.-%,

[0178] Preferably, as determined according to ISO 1628-3 in decalin, the second multiphase propylene copolymer (HECO2) has an intrinsic viscosity (IV(SF)) of the soluble fraction of from 3.0 dl / g to 7.0 dl / g, more preferably from 3.2 dl / g to 6.5 dl / g, and / or

[0179] Determined by differential scanning calorimetry (DSC) according to ISO 11357, the melting temperature Tm is in the range from 162 °C to 170 °C, more preferably from 164 °C to 168 °C.

[0180] Ethylene copolymer

[0181] The composition further comprises an ethylene copolymer as component c). The ethylene copolymer is preferably a plastomer. Preferably, based on the total weight of the composition, the ethylene copolymer is present in an amount of from 10 wt.-% to 16 wt.-%.

[0182] Preferably, determined according to ISO 1133 at 190 °C and a load of 2.16 kg, the ethylene copolymer has an MFR of from 0.3 g / 10 min to 2.5 g / 10 min 2 .

[0183] Preferably, the ethylene copolymer is a copolymer of ethylene and a comonomer, and the comonomer is selected from α-olefins having 3 to 10 carbon atoms, preferably an α-olefin having 8 carbon atoms. In other words, the ethylene copolymer is preferably an ethylene-octene copolymer.

[0184] Based on the total amount of the ethylene copolymer, the amount of the α-olefin having 3 to 10 carbon atoms (more preferably an α-olefin having 8 carbon atoms) present in the ethylene copolymer is less than 50 mol-%.

[0185] Inorganic filler

[0186] The composition further comprises an inorganic filler as component d).

[0187] The inorganic filler is preferably a mineral filler. Based on the total weight of the composition, the inorganic filler is preferably present in an amount of 18 wt.-% to 28 wt.-%.

[0188] The inorganic filler (or more preferably the mineral filler) is selected from talc, wollastonite, kaolin, mica, clay or mixtures thereof, and more preferably the filler is talc.

[0189] Preferably, as determined according to ISO 13317-3 (sedimentation diagram), the inorganic filler has a median particle size D50 of 5 μm to 20 μm.

[0190] It should be noted that the inorganic filler does not belong to the category of additive e) described herein. The inorganic filler is generally a commercially available product.

[0191] Additive

[0192] Preferably, the composition further comprises the following components, or consists of the following components:

[0193] e) An additive in an amount of 0.5 wt.-% to 5.0 wt.-% based on the total weight of the composition.

[0194] The additive can be a compound or a mixture of two or more compounds. Preferably, the additive comprises one or more of antioxidants, UV stabilizers, antistatic agents, acid scavengers, nucleating agents, carbon black or mixtures thereof, or consists of one or more of antioxidants, UV stabilizers, antistatic agents, acid scavengers, nucleating agents, carbon black or mixtures thereof. At least one additive can be added to the composition in the form of a masterbatch. Preferably, the carbon black is in the form of a carbon black masterbatch.

[0195] This additive is commercially available and is described, for example, in "Plastic Additives Handbook", 6th edition 2009 of Hans Zweifel (pages 1141 to 1190).

[0196] Polypropylene homopolymer

[0197] Preferably, the composition further comprises, or consists of, the following components:

[0198] f) a homopolypropylene (PP-H) in an amount greater than 0 wt.-% and at most 3 wt.-%, preferably 0.1 wt.-% to 2.5 wt.-%, more preferably 0.5 wt.-% to 2.0 wt.-%, based on the total weight of the composition.

[0199] Preferably, as measured according to ISO 1133 at 230 °C and a load of 2.16 kg, the homopolypropylene (PP-H) has an MFR of 1 g / 10 min to 100 g / 10 min 2 , more preferably 1.5 g / 10 min to 50 g / 10 min, and even more preferably 2 g / 10 min to 10 g / 10 min.

[0200] It should be noted that the homopolypropylene f) is not (or does not correspond to) the matrix (A) of the first multiphase propylene copolymer (HECO1) and / or the matrix of the second multiphase propylene copolymer described herein. In other words, the homopolypropylene f) is preferably a compound different from the matrix (A) of the first multiphase propylene copolymer (HECO1) a) and / or different from the matrix of the second multiphase propylene copolymer (HECO2) b) described herein.

[0201] Article

[0202] The present invention also provides an article, preferably a molded article, more preferably an injection molded article, comprising the composition according to the present invention. The article (preferably a molded article, more preferably an injection molded article) is preferably an exterior automotive part or an interior automotive part. The exterior automotive parts are selected from bumpers, rocker panels, body panels, side trims, step assists, and spoilers.

[0203] Based on the total weight of the article, the article (preferably a molded article, more preferably an injection molded article) comprises an amount of at least 60 wt.-%, more preferably at least 80 wt.-%, and most preferably at least 95 wt.-% of the inventive composition. Usually, based on the total weight of the article, the article (preferably a molded article, more preferably an injection molded article) comprises an amount of at most 100 wt.-% or at most 99.5 wt.-%, or at most 99 wt.-% of the composition according to the invention.

[0204] If applicable, all preferred embodiments of the composition according to the invention are also preferred embodiments of the article.

[0205] Use

[0206] The present invention also provides the use of the composition according to the invention for improving the paint adhesion. Preferably, the composition according to the invention is used for improving the paint adhesion on the surface of an article (preferably a molded article, more preferably an injection molded article). The article (preferably a molded article, more preferably an injection molded article) is preferably an automotive exterior part or an automotive interior part. The automotive exterior parts are selected from bumpers, sill plates, body panels, side moldings, step assist devices, and spoilers. According to the paint adhesion test described herein, the paint adhesion is determined by the delamination area. Preferably, the delamination area according to the paint adhesion test is less than 57 mm 2 , more preferably less than 55 mm 2 , more preferably less than 53 mm 2 . Usually, the delamination area is greater than 1 mm 2 or greater than 5 mm 2 or greater than 10 mm 2 or greater than 20 mm 2 .

[0207] If applicable, all preferred embodiments of the composition according to the invention and the article according to the invention are also preferred embodiments of the use according to the invention.

[0208] In particular, the present invention also relates to the use of the composition according to the invention for achieving a delamination area according to the paint adhesion test of less than 57 mm on the surface of an article (preferably a molded article, more preferably an injection molded article) 2 , more preferably less than 55 mm 2 , more preferably less than 53 mm 2 . Usually, the delamination area is greater than 1 mm 2 or greater than 5 mm 2 or greater than 10 mm 2 or greater than 20 mm 2 . Detailed Description

[0209] The present invention will now be further described by way of non-limiting examples.

[0210] Experimental section

[0211] 1. Measurement method

[0212] Unless otherwise defined, the following definitions of terms and measurement methods apply to the above general description of the present invention and the following examples.

[0213] a) Melt flow rate (MFR)

[0214] The melt flow rate (MFR) is measured according to ISO 1133 and expressed in g / 10 min. The higher the melt flow rate, the lower the viscosity of the polymer. The MFR of polypropylene 2 is measured at 230 °C and a load of 2.16 kg, and the MFR of polyethylene 2 is measured at 190 °C and a load of 2.16 kg.

[0215] The MFR of component (B) produced in the presence of component (A) 2 , is calculated using the measured value of the MFR of component (A) 2 and the measured value of the MFR of the mixture ("final") obtained after producing component (B): 2 Log(MFR

[0216] ) = weight fraction (A) * Log(MFR 最终 ) + weight fraction (B) * LOG(MFR A ) B )

[0217] b) CRYSTEX: Determination of crystalline and soluble components and their respective properties (IV and ethylene content)

[0218] The crystalline fraction (CF) and the soluble fraction (SF) of the polypropylene composition, as well as the comonomer content and the intrinsic viscosity of each fraction, were analyzed using a CRYSTEX instrument from Polymer Char (Valencia, Spain). Details of the technique and method can be found in the literature (Ljiljana Jeremic, Andreas Albrecht, Martina Sandholzer & Markus Gahleitner (2020) Rapid characterization of high-impact ethylene-propylene copolymer composition by crystallization extraction separation: comparability to standard separation methods, International Journal of Polymer Analysis and Characterization, 25:8, 581-596).

[0219] The crystalline and amorphous fractions were separated by a temperature cycle of dissolution at 160 °C, crystallization at 40 °C, and redissolution at 160 °C in 1,2,4-trichlorobenzene. The quantification of SF and CF and the determination of the ethylene content (C2) were achieved by an integrated infrared detector (IR4), and for the determination of the intrinsic viscosity (iV), an on-line 2-capillary viscometer was used.

[0220] The IR4 detector is a multi-wavelength detector that measures the IR absorbance at two different bands (CH 3 stretching vibration (centered at about 2960 cm -1 -1) and CH stretching vibration (2700 cm -1 -3000 cm -1 -1)), and these two different bands are used to determine the concentration and ethylene content in ethylene-propylene copolymers. Eight EP copolymers with known ethylene contents (determined by 13 C-NMR) in the range of 2 wt.-% to 69 wt.-% were used, and each was at various concentration ranges from 2 mg / ml to 13 mg / ml to calibrate the IR4 detector. To simultaneously meet the two characteristics (concentration and ethylene content) of various polymer concentrations expected during Crystex analysis, the following calibration equation was applied:

[0221] Conc = a + b*Abs(CH) + c*(Abs(CH)) 2 + d*Abs(CH 3) + e * (Abs(CH 3 ) 2 + f * Abs(CH) * Abs(CH 3 ) (Equation 1)

[0222] CH 3 / 1000C = a + b * Abs(CH) + c * Abs(CH 3 ) + d * (Abs(CH 3 ) / Abs(CH)) + e * (Abs(CH 3 ) / Abs(CH)) 2 (Equation 2)

[0223] The constants a to e in Equation 1 and the constants a to f in Equation 2 are determined by using the least - squares regression analysis.

[0224] The following relationship is used to convert CH 3 / 1000C to ethylene content (wt.-%):

[0225] wt.-% (ethylene in the EP copolymer) = 100 - CH 3 / 1000TC * 0.3 (Equation 3)

[0226] The contents of the soluble fraction (SF) and the crystalline fraction (CF) are related to the amounts of "cold xylene soluble" (XCS) and cold xylene insoluble (XCI) components by XS calibration, and these amounts are determined by the ISO 16152 standard gravimetric method. The XS calibration is achieved by testing various EP copolymers with XS contents in the range of 2 - 31 wt.-%. The determined XS calibration is linear:

[0227] wt.-% XS = 1.01 * wt% SF (Equation 4)

[0228] The intrinsic viscosity (iV) of the parent EP copolymer and its soluble and crystalline components is measured using an on - line 2 - capillary viscometer and correlated with the corresponding iV determined by the standard method in decalin according to ISO 1628 - 3. The calibration is carried out using various EP - PP copolymers with iV = 2 - 4 dL / g. The determined calibration curve is linear:

[0229] iV (dL / g) = a * Vsp / c (Equation 5)

[0230] The samples to be analyzed are weighed at a concentration of 10 mg / ml to 20 mg / ml. To avoid injecting possible gels and / or polymers (such as PET and PA) that are insoluble in TCB at 160 °C, the weighed samples are loaded into a stainless - steel mesh (MW 0.077 / D 0.05 mm).

[0231] After automatically filling a vial with 1,2,4-TCB containing 250 mg / l of 2,6-di-tert-butyl-4-methylphenol (BHT) as an antioxidant, the sample was dissolved at 160 °C until complete dissolution was achieved, typically for 60 min, and continuously stirred at a speed of 400 rpm. To avoid sample degradation, during the dissolution process, the polymer solution was enclosed under a N 2 atmosphere.

[0232] A certain volume of the sample solution was injected into a column filled with an inert support, and crystallization of the sample and separation of soluble components from crystalline components were carried out in the column. This process was repeated twice. At the first injection, the entire sample was measured at a high temperature to determine the iV [dl / g] and C 2 [wt.-%] of the PP composition. At the second injection, the soluble components (at low temperature) and crystalline components (at high temperature) (wt.-% SF, wt.-% C 2 、iV) in the crystallization cycle were measured.

[0233] c) Xylene cold solubles (XCS)

[0234] Xylene cold solubles (XCS, wt.-%) were determined at 25 °C according to the first edition of ISO 16152 (2005-07-01).

[0235] d) Intrinsic viscosity

[0236] The intrinsic viscosity was measured according to DIN ISO 1628 / 1, October 1999 edition (in decalin at 135 °C).

[0237] e) Quantitative microstructure by NMR spectroscopy - ethylene content in HECO

[0238] The comonomer content of the polymer was quantified using quantitative nuclear magnetic resonance (NMR) spectroscopy. Using a Bruker AvanceⅢ 400 NMR spectrometer, for 1 H and 13 C, operations were carried out at 400.15 MHz and 100.62 MHz respectively, and quantitative 13 C{ 1 H} NMR spectra were recorded in the solution state. Nitrogen was used for all pneumatics, and all spectra were recorded using a 13 C optimized 10 mm extended temperature probe at 125 °C. Approximately 200 mg of the material was dissolved in 3 ml of 1,2-tetrachloroethane-d 2 (TCE-d 2 ) and chromium-(III)-acetylacetone (Cr(acac) 3) A solution of 65 mM relaxant in the solvent was obtained (Singh, G., Kothari, A., Gupta, V., Polymer Testing 28 5 (2009), 475). To ensure the homogeneity of the solution, after preparing the initial sample in a hot block, the NMR tube was further heated in a spinning oven for at least 1 hour. After inserting the magnet, the tube was spun at 10 Hz. This setting was chosen mainly for the high resolution and quantification required to accurately determine the ethylene content. Standard single-pulse excitation was used without NOE, with an optimized tip angle, 1 s recycle delay, and a double-layer WALTZ16 decoupling scheme (Zhou, Z., Kuemmerle, R., Qiu, X., Redwine, D., Cong, R., Taha, A., Baugh, D. Winniford, B., J. Mag. Reson. 187 (2007) 225; Busico, V., Carbonniere, P., Cipullo, R., Pellecchia, R., Severn, J., Talarico, G., Macromol. Rapid Commun. 2007, 28, 1128). A total of 6144 (6k) transients were obtained for each spectrum. The quantitative 13 C{ 1 H} NMR spectra were processed, integrated, and the relevant quantitative properties were determined from the integration using a proprietary computer program. Using the chemical shift of the solvent, all chemical shifts were indirectly referenced to the central methylene group in the ethylene region (EEE) located at 30.00 ppm. This method allows for comparative reference even if this structural unit is absent. Characteristic signals corresponding to the incorporation of ethylene were observed (Cheng, H. N., Macromolecules 17 (1984), 1950).

[0239] Characteristic signals corresponding to the 2,1 erythro regio-defects were observed (as described in L. Resconi, L. Cavallo, A. Fait, F. Piemontesi, Chem. Rev. 2000, 100 (4), 1253, in Cheng, H. N., Macromolecules 1984, 17, 1950, and in W-J. Wang and S. Zhu, Macromolecules 2000, 33 1157), and corrections for the influence of regio-defects on the determination performance were required. Characteristic signals corresponding to other types of regio-defects were not observed.

[0240] Using the method of Wang et al. (Wang, W-J., Zhu, S., Macromolecules 33 (2000), 1157), by 13Integrate multiple signals in the entire spectral region of the C{ 1 H} spectrum to quantify the comonomer components. This method is chosen because of its robust nature and the ability to account for the presence of regional defects when needed. The integration region was slightly adjusted to improve the applicability of the comonomer content encountered over the entire range.

[0241] For systems where only isolated ethylene is observed in the PPEPP sequence, the method of Wang et al. was modified to reduce the effect of non-zero integrals at sites known not to exist. This method reduces the overestimation of the ethylene content in such systems and is achieved by reducing the number of sites used to determine the absolute ethylene content:

[0242] E = 0.5(Sββ + Sβγ + Sβδ + 0.5(Sαβ + Sαγ))

[0243] By using this set of sites, the corresponding integration equation becomes:

[0244] E = 0.5(I H + I G + 0.5(I C + I D ))

[0245] Use the same notation as used by Wang et al. (Wang, W-J., Zhu, S., Macromolecules 33(2000), 1157) in the article. The equation for the absolute content of propylene was not modified.

[0246] Calculate the mole percentage of comonomer incorporation in mole fraction:

[0247] E[mol-%] = 100*fE

[0248] Calculate the weight percentage of comonomer incorporation in mole fraction:

[0249] E[wt%] = 100*(fE*28.06) / ((fE*28.06)+((1 - fE)*42.08))

[0250] Use the analytical method of Kakugo et al. (Kakugo, M., Naito, Y., Mizunuma, K., Miyatake, T. Macromolecules 15(1982)1150) to determine the comonomer sequence distribution at the triad level. This method is chosen because of its robust nature and the slight adjustment of the integration region to improve the applicability of the comonomer content over a wider range.

[0251] f) Flexural modulus (FM)

[0252] The flexural modulus (FM) was determined by the three-point bending method on injection-molded specimens in accordance with ISO 178. The injection-molded specimens had dimensions of 80 × 10 × 4 mm as described in EN ISO 1873-2 3 . When determining the flexural modulus, the crosshead speed was 2 mm / min.

[0253] g) Charpy notched impact strength (Charpy NIS)

[0254] The Charpy notched impact strength was determined on injection-molded specimens in accordance with ISO 179-1eA at +23 °C and -20 °C. The injection-molded specimens had dimensions of 80 × 10 × 4 mm as described in EN ISO 1873-2 3 .

[0255] h) Coefficient of linear thermal expansion (CLTE)

[0256] The coefficient of linear thermal expansion (CLTE) was determined in accordance with ISO 11359-2:1999. The test specimens were 10 mm long segments cut from the same injection-molded specimens used for determining the flexural modulus. Measurements were made in the machine direction at a heating rate of 1 °C / min in the temperature range from -30 °C to +80 °C and at a heating rate of 1 °C / min in the temperature range from 23 °C to +80 °C.

[0257] i) Coating adhesion

[0258] Adhesion was characterized by the resistance of a decorative coating (such as a paint) after cleaning with a high-pressure washer under the following specific conditions. Injection-molded sample plates (150 mm × 80 mm × 3 mm) were produced at a melt temperature of 240 °C and a mold temperature of 50 °C. The flow front velocity was 100 mm / s. Before coating, the plates were cleaned with Zeller-Gmelin mm / s for 5 min. Subsequently, the surface was activated by flame, where a burner distributed a mixture of propane (9 l / min) and air (180 l / min) in a ratio of 1:20 over the polymer matrix at a speed of 670 mm / s. The flame treatment step was carried out twice. Then, the polymer substrate was coated with 2 layers: a primer (black, R2342) and a varnish ( R3203H).

[0259] The decorative coating is scribed onto the substrate using a Sikkens cutting tool to a total depth of approximately 130 μm (including the coating and the substrate), forming a cross with 100 mm long branches. On each coated substrate, 3 lines with corresponding crosses are cut. The cut area is further exposed to a hot water stream at a temperature of T, which is directed at an angle α towards the test plate surface at a distance d for a duration t. The water flow rate results in a water jet pressure and is determined by the type of nozzle installed at the end of the water pipe.

[0260] The following parameters are used:

[0261] T (water) = 60 °C; t = 60 s; d = 100 mm, α = 90°, water pressure is 60 bar, nozzle type = Walter 13 / 32.

[0262] Adhesion is evaluated by quantifying the area of the failed or delaminated coating (mm 2 ) for each test line. For each example, 5 specimens (150 mm × 80 mm × 3 mm) have been tested. For this purpose, images of the test lines before and after steam jet exposure are taken. Then the delaminated area is calculated using image processing software. The average failure area of the 3 test lines on 5 specimens (i.e., the average of a total of 15 test points) is used as the average failure area.

[0263] j) Median particle size D50 (sedimentation)

[0264] The median particle size D50 (sedimentation) is calculated from the particle size distribution [mass percentage] determined by gravitational liquid sedimentation according to ISO 13317-3 (sedimentation diagram).

[0265] k) Particle size and particle size distribution

[0266] Laser diffraction measurement using a Coulter LS200 is used to determine the particle size distribution. The particle size and particle size distribution are scales for measuring the particle size. The D values (D10 (or d10), D50 (or d50), and D90 (or d90)) represent the cut-off points for 10%, 50%, and 90% of the cumulative mass of the sample. When the particles are arranged in ascending order of mass as a reference, the D value can be considered as the diameter of the sphere that divides the mass of the sample into a specific percentage. For example, D10 is the diameter at which 10% of the sample mass consists of particles with a diameter smaller than this value. D50 is the diameter of the particles, where 50% of the sample mass is smaller than this value and 50% of the sample mass is larger than this value. D90 is the diameter at which 90% of the sample mass consists of particles with a diameter smaller than this value. The D50 value is also known as the median particle size. Based on the laser diffraction measurement according to ISO13320, volume D values are obtained based on the volume distribution.

[0267] i) Differential scanning calorimetry (DSC)

[0268] Differential scanning calorimetry (DSC) analysis was performed on 5 mg to 7 mg samples using a TA Instrument Q200 differential scanning calorimeter (DSC) to determine the melting temperature (T m ) and melt enthalpy (H m ), crystallization temperature (T c ) and crystallization heat (H c , H cr ). The DSC was operated in a heating / cooling / heating cycle according to ISO 11357 / Part 3 / Method C2 at a scanning rate of 10 °C / min over a temperature range of -30 °C to +225 °C.

[0269] The crystallization temperature (T c ) and crystallization heat (H c ) were determined from the cooling step, while the melting temperature (T m ) and melting enthalpy (H m ) were determined from the second heating step.

[0270] Throughout the specification, the term T c or (T cr ) is understood to be the peak temperature of crystallization determined by DSC at a cooling rate of 10 K / min (i.e., 0.16 K / sec).

[0271] 2. Examples

[0272] a) Materials

[0273] HECO1 is a high-flow multiphase propylene copolymer prepared as described below. The polymerization details are given in Table 1 below and the properties are given in Table 2 below.

[0274] HECO-A is a high-flow multiphase propylene copolymer with an MFR of 100 g / 10 min 2 , prepared using a Ziegler-Natta catalyst commercially available from LyondellBasell under the trade name “Avant ZN180M” in combination with triethylaluminum (TEAL) as a cocatalyst and dicyclopentadienyldimethoxysilane (donor D) as an external donor. The polymerization details are given in Table 1 below and the properties are given in Table 2 below.

[0275] HECO2 is a multiphase propylene copolymer (HECO) with an MFR of 11 g / 10 min 2, prepared using the Ziegler-Natta catalyst used for HPP2 in WO2014191211 A1; the preparation concept of this catalyst is generally described in, for example, patent publication texts EP491566, EP591224, and EP586390. This catalyst is used in combination with triethylaluminum (TEAL) as a cocatalyst and dicyclopentadienyl dimethoxysilane (donor D) as an external donor. The polymerization details are given in Table 1 below, and the properties are given in Table 2 below.

[0276] The propylene homopolymer HJ120UB has an MFR of 75 g / 10 min 2 (at 230 °C, 2.16 kg), and is commercially available from Borealis AG, Austria.

[0277] PP-H is a propylene homopolymer with an MFR of 75 g / 10 min 2 (at 230 °C, 2.16 kg), and is prepared in a single-loop reactor using the same metallocene catalyst as HECO1.

[0278] The ethylene-octene elastomer Engage 8100 has a density of 870 kg / m 3 and an MFR of 1 g / 10 min 2 (at 190 °C; 21.16 kg), and is commercially available from Dow Chemical Company, USA.

[0279] The ethylene-octene copolymer Engage 8137 has a density of 864 kg / m 3 and an MFR of 13 g / 10 min 2 (at 190 °C; 21.16 kg), and is commercially available from Dow Chemical Company, USA.

[0280] Talc Luzenac HAR T84 with an average particle size D50 of 11.5 μm is used as an inorganic filler and is commercially available from Imerys Talc, France.

[0281] HC001A-B1 is a polypropylene homopolymer with an MFR of 2.7 g / 10 min 2 (at 230 °C, 2.16 kg) and a density of 905 kg / m 3 and is commercially available from Borealis AG, Austria.

[0282] Additive 1 is a polyethylene-based carbon black masterbatch and is commercially available from Premix Oy, Finland under the name CBMB-LD.09.

[0283] Additive 2 is an antistatic agent, which is a glyceride and commercially available from Danisco GmbH, Austria under the trade name Dimodan HP (CAS No. 97593-29-8).

[0284] Additive 3 is a phosphorus-based antioxidant and commercially available from BASF AG, Germany under the trade name Irgafos 168 (FF) (CAS No. 31570-04-4).

[0285] Additive 4 is calcium stearate as an acid scavenger and commercially available from Baerlocher, Germany under the trade name Ceasit SW (CAS No. 1592-23-0).

[0286] Additive 5 is a sterically hindered phenol as an antioxidant and commercially available from BASF AG, Germany under the trade name Irganox 1010 (FF) (CAS No. 6683-19-8).

[0287] b) Polymerization of HECO1

[0288] The following catalysts are used for the preparation of HECO1. The metallocene complexes have been used as described in WO 2019 / 179959 A1:

[0289]

[0290] [rac-trans-dimethylsilanediyl[2-methyl-4,8-bis-(3',5'-dimethylphenyl)-1,5,6,7-tetrahydro-s-dicyclopentadienylphenyl-1-yl][2-methyl-4-(3',5'-dimethylphenyl)-5-methoxy-6-tert-butylindene-1-yl]zirconium dichloride

[0291] The supported metallocene catalyst is produced similar to IE2 in WO 2019 / 179959 A1.

[0292] HECO1 is prepared using the said catalyst in a Borstar PP pilot plant, which uses a sequential process including a prepolymerization reactor, a loop reactor and two gas-phase reactors. The polymerization and reactor conditions are given in Table 1 below.

[0293] Table 1: Preparation of the multiphase propylene copolymers HECO1, HECO-A and HECO2

[0294]

[0295]

[0296]

[0297] The properties of the multiphase propylene copolymers HECO1, HECO-A, and HECO2 are given in Table 2 below.

[0298] Table 2: Properties of the Multiphase Propylene Copolymer

[0299] HECO1 HECO-A HECO2 Particle data <![CDATA[MFR 2 > g / 10min 91 100 11 Tm ℃ 152 165 165 Tc ℃ 118 121 116 Crystex data SF wt.-% 12.1 15 31.3 CF wt.-% 87.9 85 68.7 C2 wt.-% 3.5 8.8 15.1 C2(SF) wt.-% 22.2 39 38.6 C2(CF) wt.-% 0 3.5 5.1 IV dl / g 1.3 1.4 2.1 IV(SF) dl / g 2.7 2.9 3.6 IV(CF) dl / g 1.1 1.1 1.5 IV(SF) / IV(CF) - 2.45 2.64 2.39

[0300] The composition was prepared by melt blending using a twin-screw extruder Coperion ZSK-40. During the mixing process, the following temperature profile was set: 190 °C, 210 °C, 230 °C, 210 °C.

[0301] The components and amounts used in preparing the polypropylene composition IE1 of the present invention and the comparative polypropylene compositions CE1, CE2, and CE3 are summarized in Table 3 below.

[0302] Table 3: Inventive Composition and Comparative Compositions

[0303]

[0304]

[0305] The properties of the polypropylene composition IE1 of the present invention and the comparative polypropylene compositions CE1, CE2, and CE3 are summarized in Table 4 below.

[0306] Table 4: Properties of the Inventive Composition and Comparative Compositions

[0307]

[0308] From the results shown in Table 4, it can be seen that IE1 performs best in the delamination test, while showing high stiffness (flexural modulus), good impact strength, and comparable CLTE.

Claims

1. A composition for automotive exterior parts, the composition comprising a) a first multiphase propylene copolymer (HECO1) based on 30 wt.-% to 45 wt.-% of the total weight of the composition, the first multiphase propylene copolymer having Melt flow rate MFR determined according to ISO 1133 at 230 °C and 2.16 kg load is from 70 g / 10 min to 250 g / 10 min 2 , a soluble fraction (SF) content of 6 wt.-% to 22 wt.-% based on the total weight of the first multiphase propylene copolymer (HECO1), as determined according to the CRYSTEX method, and As determined by Fourier transform infrared spectroscopy (FTIR) calibrated with 13 13C-NMR spectroscopy, the ethylene content C2(SF) of the soluble fraction (SF) based on the multiphase propylene copolymer (HECO1) is from 15 wt.-% to 30 wt.-%. b) a second multiphase propylene copolymer (HECO2) based on 15 wt.-% to 30 wt.-% of the total weight of the composition, the second multiphase propylene copolymer having MFR determined according to ISO 1133 at 230 °C and 2.16 kg load to be from 5 g / 10 min to 15 g / 10 min 2 , a soluble fraction (SF) content of 25 wt.-% to 45 wt.-% based on the second multiphase propylene copolymer (HECO2), as determined according to the CRYSTEX method, and As determined by Fourier transform infrared spectroscopy (FTIR) calibrated with 13 13C-NMR spectroscopy, the ethylene content C2(SF) of the soluble fraction (SF) based on the multiphase propylene copolymer (HECO2) is from 30 wt.-% to 50 wt.-%. c) an ethylene copolymer based on 8 wt.-% to 18 wt.-% of the total weight of the composition, the ethylene copolymer having Density determined in accordance with ISO 1183 is 860 kg / m 3 to 880 kg / m 3 and MFR as determined according to ISO 1133 at 190 °C and a load of 2.16 kg of from 0.1 g / 10 min to 3.0 g / 10 min 2 , d) an inorganic filler based on 15 wt.-% to 30 wt.-% of the total weight of the composition, wherein Determined according to ISO 1133 at 230 °C and a load of 2.16 kg, the composition has an MFR of 15 g / 10 min to 30 g / 10 min 2 .

2. The composition according to claim 1, wherein as determined by differential scanning calorimetry (DSC) according to ISO 11357, the first multiphase propylene copolymer (HECO1) has a melting temperature Tm in the range of 145 °C to 160 °C, and / or an intrinsic viscosity of the soluble fraction (IV(SF)) of 2.0 dl / g to 3.5 dl / g as determined in decalin according to ISO 1628-3.

3. The composition according to any one of the preceding claims, wherein as determined in decalin according to ISO 1628-3, the second multiphase propylene copolymer (HECO2) has an intrinsic viscosity of the soluble fraction (IV(SF)) of 3.0 dl / g to 7.0 dl / g, and / or a melting temperature Tm in the range of 162 °C to 170 °C as determined by differential scanning calorimetry (DSC) according to ISO 11357.

4. The composition according to any one of the preceding claims, wherein the ethylene copolymer is a copolymer of ethylene and an α-olefin having 3 to 10 carbon atoms, preferably a copolymer of ethylene and an α-olefin having 8 carbon atoms.

5. The composition according to any one of the preceding claims, further comprising e) an additive based on 0.5 wt.-% to 5.0 wt.-% of the total weight of the composition.

6. The composition according to claim 5, wherein the additive comprises one or more of antioxidants, UV stabilizers, antistatic agents, acid scavengers, nucleating agents, carbon black or mixtures thereof.

7. The composition according to any one of the preceding claims, wherein the inorganic filler is selected from talc, wollastonite, kaolin, mica, clay or mixtures thereof, preferably the filler is talc.

8. The composition according to any one of the preceding claims, wherein the inorganic filler has a median particle size D50 of 5 μm to 20 μm.

9. The composition according to any one of the preceding claims, further comprising f) An atactic polypropylene (PP-H) of up to 3 wt.-% based on the total weight of the composition.

10. The composition according to claim 9, wherein, The propylene homopolymer (PP-H) has an MFR of from 1 g / 10 min to 100 g / 10 min as measured according to ISO 1133 at 230 °C and a load of 2.16 kg 2 .

11. The composition according to any one of the preceding claims, wherein, Based on the total weight of the first multiphase propylene copolymer (HECO1), the content of the component (XCS component) soluble in cold xylene at 25 °C in the first multiphase propylene copolymer (HECO1) is in the range of 6 wt.-% to 22 wt.-%, and / or As determined by Fourier transform infrared spectroscopy (FTIR) calibrated with 13 13C-NMR spectroscopy, based on the total weight of the first multiphase propylene copolymer (HECO1), the first multiphase propylene copolymer (HECO1) has a total ethylene content (total C2) in the range of 1.8 wt.-% to 6.5 wt.-%.

12. The composition according to any one of the preceding claims, wherein, Measured on an injection-molded specimen according to ISO 178, the composition has a flexural modulus in the range of 1750 MPa to 2750 MPa.

13. The composition according to any one of the preceding claims, wherein, Determined on injection molded specimens according to ISO 179 / eA, the composition has a Charpy notched impact strength in the range of 30 kJ / m 2 to 75 kJ / m 2 at 23 °C.

14. An article comprising the composition according to any one of the preceding claims, preferably an automotive exterior part.

15. Use of the composition according to any one of claims 1 to 13 for improving paint adhesion.

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