EP4702088A1

EP4702088A1 - Pigmented mica-containing polypropylene compositions partially derived from recyclates for automotive exterior applications

Info

Publication number: EP4702088A1
Application number: EP24726939.2A
Authority: EP
Inventors: Daniela MILEVA; Hermann Braun; Mario Eggetsberger; Dietmar SALABERGER; Christophe SALLES; Emmanuel BOISSARD
Original assignee: Borealis GmbH
Current assignee: Borealis GmbH
Priority date: 2023-04-25
Filing date: 2024-04-24
Publication date: 2026-03-04
Also published as: WO2024223637A1; CN121057774A

Abstract

A polypropylene composition (PC) being a mixed-plastic polypropylene blend having an MFR₂ of 5.0 to 40.0 g/10 min, an energy to max force at -30 °C of 6.0 to 50.0 J, a puncture energy at -30 °C of 6.0 to 50.0 J, a limonene content of 0.10 to 25.0 ppm, 0.1 to 3.0 wt.-% of mica, and 0.01 to 1.00 wt.-% of coloured pigment; wherein the polymeric part of said polypropylene composition (PC) has: i) a CRYSTEX QC crystalline fraction (CF) having an intrinsic viscosity (iV(CF)) of 1.00 to 2.00 dL/g; ii) a CRYSTEX QC soluble fraction (SF) having an intrinsic viscosity (iV(SF)) of 1.00 to 2.40 dL/g; and iii) an intrinsic viscosity ratio (iV(SF)/iV(CF)) of 1.00 to 2.00.

Description

Pigmented mica-containing polypropylene compositions partially derived from recyclates for automotive exterior applications

Field of the Invention

The present invention relates to a polypropylene composition (PC) being a mixed-plastic polypropylene blend containing recycled material, to articles comprising said polypropylene composition (PC), and to processes for producing said articles.

Background to the Invention

Polyolefins, in particular polyethylene and polypropylene, are increasingly consumed in large amounts in a wide range of applications, including packaging for food and other goods, fibres, automotive components, and a great variety of manufactured articles.

Polypropylene based materials offer significant potential for mechanical recycling, as these materials are extensively used in packaging. Taking into account the huge amount of waste collected compared to the amount of waste recycled back into the stream, there is still a great potential for intelligent reuse of plastic waste streams and for mechanical recycling of plastic wastes.

Development of polyolefins and polyolefin blends is often focused on the continuous goal of improving the balance of mechanical properties, and also the more effective handling of waste streams, for both economical and also environmental reasons. It is usually understood that the use of recycled materials in polymer blends tends to lead to a degradation of mechanical properties, since the mechanical properties of virgin polymers can easily be modified by the polymerization conditions, whereas controlling the properties of a recycled material is intrinsically more difficult, resulting in poorer performance of these compositions.

Surface appearance, in addition to mechanical performance, is of extremely high importance for non-painted injection-moulded articles. Recently, the tendency moves towards obtaining surface appearance close to natural materials such as stone, wood, etc. Such special features are known as “speckled effect”. In order to generate this “speckled effect” specialized masterbatch solutions featuring specks or flecks that don’t melt away during molding process are used. Different particle sizes and colours can be added or mixed together to create a unique look.

One potential particle for achieving a “speckled effect” is mica. Whilst mica has been employed as a reinforcing filler in polypropylene compositions, it is known to the person skilled in the art that the addition of mica results in inferior impact/puncture properties, as may be seen in EP 3 489 296 Al, for example. As such, the development of mica-containing compositions, in particular recy elate -based mica-containing compositions, that are able to maintain impact/puncture properties is a particularly desirous target in polymer development.

Summary of the Invention

The present invention is based on the finding that the blending of mica-containing pigment masterbatch with a particular recyclate blend, a heterophasic propylene-ethylene copolymer, an ethylene-octene elastomer, an inorganic filler, and various additives results in the formation of polypropylene compositions with balanced mechanical properties, in particular low temperature puncture energy and energy to max force, in addition to the desired “speckled effect”.

Alternatively, the inventive polypropylene compositions may be described in terms of its composition properties, rather than the components used in the blending.

Therefore, in a first aspect, the present invention is directed, in its broadest sense, to a polypropylene composition (PC) being a mixed-plastic polypropylene blend, wherein the polypropylene composition (PC) has: a) a melt flow rate (MFR2), determined according to ISO 1133 at 230 °C and 2.16 kg, in the range from 5.0 to 40.0 g/10 min; b) an energy to max force at -30 °C, measured according to ISO 6603-2 using injection- moulded plaques of 60 x 60 x 3 mm and a test speed of 4.4 m/s, in the range from 6.0 to 50.0 J; c) a puncture energy at -30 °C, measured according to ISO 6603-2 using injection- moulded plaques of 60 x 60 x 3 mm and a test speed of 4.4 m/s, in the range from 6.0 to 50.0 J; and d) a limonene content, determined by solid phase microextraction (HS-SPME-GC-MS), in the range from 0.10 to 25.0 ppm; e) a content of mica particles in the range from 0.1 to 3.0 wt.-%, relative to the total weight of the polypropylene composition (PC); and f) a content of coloured pigment in the range from 0.01 to 1.00 wt.-%, relative to the total weight of the polypropylene composition (PC); wherein the polymeric part of said polypropylene composition (PC) has: i) a crystalline fraction (CF) having an intrinsic viscosity (iV(CF)), determined by CRYSTEX QC analysis, in the range from 1.00 to 2.00 dL/g; ii) a soluble fraction (SF) having an intrinsic viscosity (iV(SF)), determined by CRYSTEX QC analysis, in the range from 1.00 to 2.40 dL/g; and iii) an intrinsic viscosity ratio (iV(SF)ZiV(CF)), determined by CRYSTEX QC analysis, in the range from 1.00 to 2.00.

It is preferred that the polypropylene composition (PC) is obtainable by blending at least components a) to f) and optionally component g): a) from 20.0 to 50.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a heterophasic propylene -ethylene copolymer (HECO); b) from 1.0 to 30.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a mixed-plastic polypropylene blend (B) having a melt flow rate (MFR2), determined according to ISO 1133 at 230 °C and 2.16 kg, in the range from 8.0 to 25.0 g/10 min; c) from 14.0 to 24.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of an ethylene-octene elastomer (EC); d) from 5.0 to 17.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of an inorganic filler (F) other than mica; e) from 1.0 to 5.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a mica-containing pigment masterbatch (MPM) that comprises mica, at least one coloured pigment, and a carrier polymer; f) from 0.2 to 5.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of further additives (A); and g) from 0.0 to 10.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a propylene homopolymer (h-PP), wherein the total contents of components a) to f) and optionally component g) add up to at least 95 wt.-%, more preferably at least 98 wt.-%, most preferably 100 wt.-%, relative to the total weight of the polypropylene composition (PC).

In a second aspect, the present invention is directed to a polypropylene composition (PC) having a melt flow rate (MFR2), determined according to ISO 1133 at 230 °C and 2.16 kg, in the range from 5.0 to 40.0 g/10 min and being obtainable by blending at least components a) to f) and optionally component g): a) from 20.0 to 50.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a heterophasic propylene -ethylene copolymer (HECO); b) from 1.0 to 30.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a mixed-plastic polypropylene blend (B) having a melt flow rate (MFR2), determined according to ISO 1133 at 230 °C and 2.16 kg, in the range from 8.0 to 25.0 g/10 min and a limonene content, determined by solid phase microextraction (HS-SPME-GC-MS), in the range from 0.10 to 100 ppm; c) from 14.0 to 24.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of an ethylene-octene elastomer (EC); d) from 5.0 to 17.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of an inorganic fdler (F) other than mica; e) from 1.0 to 5.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a mica-containing pigment masterbatch (MPM) that comprises mica, at least one coloured pigment, and a carrier polymer; f) from 0.2 to 5.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of further additives (A);and g) from 0.0 to 10.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a propylene homopolymer (h-PP), wherein the total contents of components a) to f) and optionally component g) add up to at least 95 wt.-%, more preferably at least 98 wt.-%, most preferably 100 wt.-%, relative to the total weight of the polypropylene composition (PC).

In a third aspect, the present invention is directed to an article, preferably an injection- moulded article, comprising the polypropylene composition (PC) of the first or second aspects in an amount of at least 95 wt.-%, more preferably at least 98 wt.-%, most preferably at least 99 wt.-%.

In a final aspect, the present invention is directed to a process for producing articles of the third aspect, comprising the steps of: a) blending a heterophasic propylene -ethylene copolymer (HECO), a mixed-plastic polypropylene blend (B), an ethylene -octene elastomer (EC), an inorganic filler (F), and further additives (A), thereby obtaining a polymer composition (PE) b) injection moulding the polymer composition (PE) to form an injection-moulded article, wherein a mica-containing pigment masterbatch (MPM) is added during the blending of step a) or during the injection moulding of step b).

Definitions

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although, any methods and materials similar or equivalent to those described herein can be used in practice for testing of the present invention, the preferred materials and methods are described herein. In describing and claiming the present invention, the following terminology will be used in accordance with the definitions set out below.

Unless clearly indicated otherwise, use of the terms “a,” “an,” and the like refers to one or more.

In the following, amounts are given in % by weight (wt.-%) unless it is stated otherwise. A propylene homopolymer is a polymer that essentially consists of propylene monomer units. Due to impurities especially during commercial polymerization processes, a propylene homopolymer can comprise up to 0. 1 mol% comonomer units, preferably up to 0.05 mol% comonomer units and most preferably up to 0.01 mol% comonomer units.

A propylene copolymer is a copolymer of propylene monomer units and comonomer units, preferably selected from ethylene and C-rCs alpha-olefins. A propylene random copolymer is a propylene copolymer wherein the comonomer units are randomly distributed along the polymer chain, whilst a propylene block copolymer comprises blocks of propylene monomer units and blocks of comonomer units. Propylene random copolymers can comprise comonomer units from one or more comonomers different in their amounts of carbon atoms.

Heterophasic propylene copolymers typically comprise: a) a crystalline propylene homopolymer or copolymer matrix (M); and b) an elastomeric rubber, preferably a propylene-ethylene copolymer (E);

In case of a random heterophasic propylene copolymer, said crystalline matrix phase is a random copolymer of propylene and at least one alpha-olefin comonomer.

The elastomeric phase can be a propylene copolymer with a high amount of comonomer that is not randomly distributed in the polymer chain but is distributed in a comonomer-rich block structure and a propylene -rich block structure. A heterophasic polypropylene usually differentiates from a one-phasic propylene copolymer in that it shows two distinct glass transition temperatures Tg which are attributed to the matrix phase and the elastomeric phase.

For the purposes of the present description and of the subsequent claims, the term “recycled waste” is used to indicate a material recovered from both post-consumer waste and industrial waste, as opposed to virgin polymers. Post-consumer waste refers to objects having completed at least a first use cycle (or life cycle), i.e. having already served their first purpose; while industrial waste refers to manufacturing scrap, which does not normally reach a consumer.

The term “virgin” denotes the newly produced materials and/or objects prior to their first use, which have not already been recycled.

The term “recycled material” such as used herein denotes materials reprocessed from “recycled waste”.

A polymer blend denotes a mixture of two or more polymeric components. In general, the blend can be prepared by mixing the two or more polymeric components. Suitable mixing procedures known in the art are post-polymerization blending procedures.

Post-polymerization blending can be dry blending of polymeric components such as polymer powders and/or compounded polymer pellets or melt blending by melt mixing the polymeric components.

A mixed-plastic polypropylene blend indicates that the blend predominantly comprises polypropylene; however, small amounts of other plastic are present. Recyclate blends, in particular post-consumer recyclate blends, are almost always mixed-plastic blends, which reflects the efficiency of the sorting in state of the art recycling processes.

The term “coloured pigment” refers to any pigment that is not a white pigment.

The present invention will now be described in more detail.

Detailed Description

Polypropylene composition (PC) of the first aspect

The present invention is directed, in a first aspect, to a polypropylene composition (PC) being a mixed-plastic polypropylene blend. The polypropylene composition (PC) has a melt flow rate (MFR2), determined according to ISO 1133 at 230 °C and 2.16 kg, in the range from 5.0 to 40.0 g/ 10 min, more preferably in the range from 10.0 to 30.0 g/10 min, most preferably in the range from 15.0 to 25.0 g/10 min.

The polypropylene composition (PC) has an energy to max force at -30 °C, measured according to ISO 6603-2 using injection-moulded plaques of 60 x 60 x 3 mm and a test speed of 4.4 m/s, in the range from 6.0 to 50.0 J, more preferably in the range from 8.0 to 30.0 J, most preferably in the range from 10.0 to 20.0 J.

The polypropylene composition (PC) preferably has an energy to max force at +23 °C, measured according to ISO 6603-2 using injection-moulded plaques of 60 x 60 x 3 mm and a test speed of 4.4 m/s, in the range from 10.0 to 30.0 J, more preferably in the range from 12.0 to 25.0 J, most preferably in the range from 15.0 to 20.0 J.

The polypropylene composition (PC) has a puncture energy at -30 °C, measured according to ISO 6603-2 using injection-moulded plaques of 60 x 60 x 3 mm and a test speed of 4.4 m/s, in the range from 6.0 to 50.0 J, more preferably in the range from 8.0 to 30.0 J, most preferably in the range from 10.0 to 20.0 J.

The polypropylene composition (PC) preferably has a puncture energy at +23 °C, measured according to ISO 6603-2 using injection-moulded plaques of 60 x 60 x 3 mm and a test speed of 4.4 m/s, in the range from 15.0 to 50.0 J, more preferably in the range from 20.0 to 45.0 J, most preferably in the range from 25.0 to 40.0 J.

The polypropylene composition (PC) has a limonene content, determined by solid phase microextraction (HS-SPME-GC-MS), in the range from 0.10 to 25.0 ppm.

The propylene composition (PC) has a content of mica particles in the range from 0.1 to 3.0 wt.-%, more preferably in the range from 0.3 to 2.0 wt.-%, most preferably in the range from 0.5 to 1.5 wt.-%, relative to the total weight of the polypropylene composition (PC). The polypropylene composition (PC) has a content of coloured pigment in the range from 0.01 to 1.00 wt.-%, more preferably in the range from 0.01 to 0.50 wt.-%, most preferably in the range from 0.01 to 0.20 wt.-%, relative to the total weight of the polypropylene composition (PC).

The coloured pigment may be a single coloured pigment or more than one coloured pigment. The one or more coloured pigments are preferably selected from black pigments, most preferably the coloured pigment is carbon black.

The polypropylene composition (PC) preferably has a flexural modulus, determined according to ISO 178 using 80x 10x4 mm³ test bars injection-moulded in line with ISO 19069-2, in the range from 1000 to 2000 MPa, more preferably in the range from 1200 to 1800 MPa, most preferably in the range from 1400 to 1600 MPa.

The polypropylene composition (PC) preferably has a Charpy Notched impact strength at 23 °C, determined according to ISO 179 using 80x 10x4 mm³ test bars injection-moulded in line with ISO 19069-2, in the range from 20 to 100 kJ/m², more preferably in the range from 25 to 80 kJ/m², most preferably in the range from 35 to 60 kJ/m².

The polymeric part of the polypropylene composition (PC) may be characterized according to the CRY STEX QC method using trichlorobenzene (TCB) as a solvent. This method is described below in the determination methods section. The crystalline fraction (CF) contains for the most part the matrix phase and only a small part of the elastomeric phase and the soluble fraction (SF) contains for the most part the elastomeric phase and only a small part of the matrix phase. In some cases, this method results in more useful data, since the crystalline fraction (CF) and the soluble fraction (SF) more accurately correspond to the matrix and elastomeric phases respectively. Due to the differences in the separation methods of xylene extraction and CRYSTEX QC method the properties of XCS/XCI fractions on the one hand and crystalline/soluble (CF/SF) fractions on the other hand are not exactly the same, meaning that the amounts of matrix phase and elastomeric phase can differ as well as the properties. The polymeric part of the polypropylene composition (PC) preferably has an ethylene content (C2(total)), determined by CRYSTEX QC analysis, in the range from 10.0 to 30.0 wt.-%, more preferably in the range from 17.0 to 29.0 wt.-%, most preferably in the range from 24.0 to 28.0 wt.-%.

The polymeric part of the polypropylene composition (PC) preferably has an intrinsic viscosity (iV(total)), determined by CRYSTEX QC analysis, in the range from 1.00 to 2.50 dL/g, more preferably in the range from 1.20 to 2.00 dL/g, most preferably in the range from 1.30 to 1.70 dL/g.

The polymeric part of the polypropylene composition (PC) preferably has a soluble fraction (SF) content, determined by CRYSTEX QC analysis, in the range from 25.0 to 45.0 wt.-%, more preferably in the range from 30.0 to 40.0 wt.-%, most preferably in the range from 32.0 to 37.0 wt.-%

Said soluble fraction (SF) preferably has an ethylene content (C2(SF)) determined by CRYSTEX QC analysis, in the range from 45.0 to 75.0 wt.-%, more preferably in the range from 50.0 to 72.0 wt.-%, most preferably in the range from 55.0 to 70.0 wt.-%.

Said soluble fraction (SF) has an intrinsic viscosity (iV(SF)), determined by CRYSTEX QC analysis, in the range from 1.00 to 2.40 dL/g, more preferably in the range from 1.30 to 2.30 dL/g, most preferably in the range from 1.60 to 2.20 dL/g.

The polymeric part of the polypropylene composition (PC) preferably has a crystalline fraction (CF) content, determined by CRYSTEX QC analysis, in the range from 55.0 to 75.0 wt.-%, more preferably in the range from 60.0 to 70.0 wt.-%, most preferably in the range from 63.0 to 68.0 wt.-%

Said crystalline fraction (CF) preferably has an ethylene content (C2(CF)) determined by CRYSTEX QC analysis, in the range from 0.0 to 10.0 wt.-%, more preferably in the range from 2.0 to 8.0 wt.-%, most preferably in the range from 4.0 to 7.0 wt.-%. Said crystalline fraction (CF) has an intrinsic viscosity (iV(CF)), determined by CRYSTEX QC analysis, in the range from 1.00 to 2.00 dL/g, more preferably in the range from 1.10 to 1.80 dL/g, most preferably in the range from 1.20 to 1.60 dL/g.

The ratio of the intrinsic viscosity of the soluble and crystalline fractions, (iV(SF)/iV(CF)), determined by CRYSTEX QC analysis, is in the range from 1.00 to 2.00, more preferably in the range from 1.20 to 1.80, most preferably in the range from 1.40 to 1.70.

The polypropylene composition (PC) is preferably obtainable by blending at least components a) to f) and optionally component g): a) from 20.0 to 50.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a heterophasic propylene -ethylene copolymer (HECO); b) from 1.0 to 30.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a mixed-plastic polypropylene blend (B) having a melt flow rate (MFR2), determined according to ISO 1133 at 230 °C and 2.16 kg, in the range from 8.0 to 25.0 g/10 min; c) from 14.0 to 24.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of an ethylene-octene elastomer (EC); d) from 5.0 to 17.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of an inorganic filler (F) other than mica; e) from 1.0 to 5.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a mica-containing pigment masterbatch (MPM) that comprises mica, at least one coloured pigment, and a carrier polymer; f) from 0.2 to 5.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of further additives (A); and g) from 0.0 to 10.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a propylene homopolymer (h-PP).

The total contents of components a) to f) and optionally component g) add up to at least 95 wt.-%, more preferably at least 98 wt.-%, most preferably 100 wt.-%, relative to the total weight of the polypropylene composition (PC). More preferably, the polypropylene composition (PC) is obtainable by blending at least components a) to f) and optionally component g): a) from 22.0 to 45.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a heterophasic propylene -ethylene copolymer (HECO); b) from 10.0 to 28.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a mixed-plastic polypropylene blend (B) having a melt flow rate (MFR2), determined according to ISO 1133 at 230 °C and 2.16 kg, in the range from 8.0 to 25.0 g/10 min; c) from 16.0 to 22.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of an ethylene-octene elastomer (EC); d) from 10.0 to 17.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of an inorganic fdler (F) other than mica; e) from 1.5 to 5.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a mica-containing pigment masterbatch (MPM) that comprises mica, at least one coloured pigment, and a carrier polymer; f) from 0.2 to 5.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of further additives (A); and g) from 3.0 to 9.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a propylene homopolymer (h-PP).

Most preferably, the polypropylene composition (PC) is obtainable by blending at least components a) to f) and optionally component g): a) from 25.0 to 40.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a heterophasic propylene -ethylene copolymer (HECO); b) from 15.0 to 25.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a mixed-plastic polypropylene blend (B) having a melt flow rate (MFR2), determined according to ISO 1133 at 230 °C and 2.16 kg, in the range from 8.0 to 25.0 g/10 min; c) from 18.0 to 20.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of an ethylene-octene elastomer (EC); d) from 12.0 to 16.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of an inorganic fdler (F) other than mica; e) from 2.0 to 5.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a mica-containing pigment masterbatch (MPM) that comprises mica, at least one coloured pigment, and a carrier polymer; f) from 0.2 to 5.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of further additives (A); and g) from 5.0 to 8.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a propylene homopolymer (h-PP).

The blending of the polypropylene composition (PC) may be carried out according to a process comprising the steps of: a) providing the heterophasic propylene-ethylene copolymer (HECO), the mixed- plastic polypropylene blend (B), the ethylene -octene elastomer (EC), the inorganic filler (F) other than mica, the mica-containing pigment masterbatch (MPM), the further additives (A) and optionally the propylene homopolymer (h-PP); and b) blending and extruding the heterophasic propylene-ethylene copolymer (HECO), the mixed-plastic polypropylene blend (B), the ethylene-octene elastomer (EC), the inorganic filler (F) other than mica and the further additives (A) at a temperature in the range from 120 to 250 °C in an extruder, preferably a twin-screw extruder, thereby generating the polypropylene composition (PC), preferably in pellet form.

Alternatively, the blending of the polypropylene composition (PC) may be carried out according to a process comprising the steps of: a) providing the heterophasic propylene-ethylene copolymer (HECO), the mixed- plastic polypropylene blend (B), the ethylene-octene elastomer (EC), the inorganic filler (F) other than mica, the further additives (A) and optionally the propylene homopolymer (h-PP); b) blending and extruding the heterophasic propylene-ethylene copolymer (HECO), the mixed-plastic polypropylene blend (B), the ethylene-octene elastomer (EC), the inorganic filler (F) other than mica and the further additives (A) at a temperature in the range from 120 to 250 °C in an extruder, preferably a twin-screw extruder, thereby generating a precursor polypropylene composition, preferably in pellet form; and c) blending the precursor polypropylene composition and the mica-containing pigment masterbatch (MPM), during an injection moulding process, thereby generating an injection-moulded article comprising the polypropylene composition (PC).

In particular, it is preferred to use a conventional compounding or blending apparatus, e.g. a Banbury mixer, a 2-roll rubber mill, Buss-co-kneader or a twin-screw extruder. More preferably, mixing is accomplished in a co-rotating twin-screw extruder. The polymer materials recovered from the extruder are usually in the form of pellets.

Polypropylene composition (PC) of the second aspect

The polypropylene composition (PC) of the second aspect is obtainable by blending at least components a) to f) and optionally component g): a) from 20.0 to 50.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a heterophasic propylene -ethylene copolymer (HECO); b) from 1.0 to 30.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a mixed-plastic polypropylene blend (B) having a melt flow rate (MFR2), determined according to ISO 1133 at 230 °C and 2.16 kg, in the range from 8.0 to 25.0 g/10 min and a limonene content, determined by solid phase microextraction (HS-SPME-GC-MS), in the range from 0.10 to 100 ppm; c) from 14.0 to 24.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of an ethylene-octene elastomer (EC); d) from 5.0 to 17.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of an inorganic fdler (F) other than mica; e) from 1.0 to 5.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a mica-containing pigment masterbatch (MPM) that comprises mica, at least one coloured pigment, and a carrier polymer; f) from 0.2 to 5.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of further additives (A); and g) from 0.0 to 10.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a propylene homopolymer (h-PP). The total contents of components a) to f) and optionally component g) add up to at least 95 wt.-%, more preferably at least 98 wt.-%, most preferably 100 wt.-%, relative to the total weight of the polypropylene composition (PC).

More preferably, the polypropylene composition (PC) is obtainable by blending at least components a) to f) and optionally component g): a) from 22.0 to 45.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a heterophasic propylene -ethylene copolymer (HECO); b) from 10.0 to 28.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a mixed-plastic polypropylene blend (B) having a melt flow rate (MFR2), determined according to ISO 1133 at 230 °C and 2.16 kg, in the range from 8.0 to 25.0 g/10 min and a limonene content, determined by solid phase microextraction (HS-SPME-GC-MS), in the range from 0.10 to 100 ppm; c) from 16.0 to 22.0 w wt.-%, relative to the total weight of the polypropylene composition (PC), of an ethylene-octene elastomer (EC); d) from 10.0 to 17.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of an inorganic fdler (F) other than mica; e) from 1.5 to 5.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a mica-containing pigment masterbatch (MPM) that comprises mica, at least one coloured pigment, and a carrier polymer; f) from 0.2 to 5.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of further additives (A); and g) from 3.0 to 9.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a propylene homopolymer (h-PP).

Most preferably, the polypropylene composition (PC) is obtainable by blending at least components a) to f) and optionally component g): a) from 25.0 to 40.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a heterophasic propylene -ethylene copolymer (HECO); b) from 15.0 to 25.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a mixed-plastic polypropylene blend (B) having a melt flow rate (MFR2), determined according to ISO 1133 at 230 °C and 2.16 kg, in the range from 8.0 to 25.0 g/10 min and a limonene content, determined by solid phase microextraction (HS-SPME-GC-MS), in the range from 0.10 to 100 ppm; c) from 18.0 to 20.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of an ethylene-octene elastomer (EC); d) from 12.0 to 16.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of an inorganic fdler (F) other than mica; e) from 2.0 to 5.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a mica-containing pigment masterbatch (MPM) that comprises mica, at least one coloured pigment, and a carrier polymer; f) from 0.2 to 5.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of further additives (A); and g) from 5.0 to 8.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a propylene homopolymer (h-PP).

The blending of the polypropylene composition (PC) may be carried out according to a process comprising the steps of: a) providing the heterophasic propylene-ethylene copolymer (HECO), the mixed- plastic polypropylene blend (B), the ethylene-octene elastomer (EC), the inorganic filler (F) other than mica, the mica-containing pigment masterbatch (MPM), the further additives (A) and optionally the propylene homopolymer (h-PP); and b) blending and extruding the heterophasic propylene-ethylene copolymer (HECO), the mixed-plastic polypropylene blend (B), the ethylene-octene elastomer (EC), the inorganic filler (F) other than mica and the further additives (A) at a temperature in the range from 120 to 250 °C in an extruder, preferably a twin-screw extruder, thereby generating the polypropylene composition (PC), preferably in pellet form.

Alternatively, the blending of the polypropylene composition (PC) may be carried out according to a process comprising the steps of: a) providing the heterophasic propylene-ethylene copolymer (HECO), the mixed- plastic polypropylene blend (B), the ethylene-octene elastomer (EC), the inorganic filler (F) other than mica, and the further additives (A); b) blending and extruding the heterophasic propylene -ethylene copolymer (HECO), the mixed-plastic polypropylene blend (B), the ethylene-octene elastomer (EC), the inorganic filler (F) other than mica, the further additives (A) and optionally the propylene homopolymer (h-PP) at a temperature in the range from 120 to 250 °C in an extruder, preferably a twin-screw extruder, thereby generating a precursor polypropylene composition, preferably in pellet form; and c) blending the precursor polypropylene composition and the mica-containing pigment masterbatch (MPM), during an injection moulding process, thereby generating an injection-moulded article comprising the polypropylene composition (PC).

The polypropylene composition (PC) has a melt flow rate (MFR2), determined according to ISO 1133 at 230 °C and 2.16 kg, in the range from 5.0 to 40.0 g/ 10 min, more preferably in the range from 10.0 to 30.0 g/10 min, most preferably in the range from 15.0 to 25.0 g/10 min.

The polypropylene composition (PC) preferably has an energy to max force at -30 °C, measured according to ISO 6603-2 using injection-moulded plaques of 60 x 60 x 3 mm and a test speed of 4.4 m/s, in the range from 6.0 to 50.0 J, more preferably in the range from 8.0 to 30.0 J, most preferably in the range from 10.0 to 20.0 J.

The polypropylene composition (PC) preferably has a puncture energy at -30 °C, measured according to ISO 6603-2 using injection-moulded plaques of 60 x 60 x 3 mm and a test speed of 4.4 m/s, in the range from 6.0 to 50.0 J, more preferably in the range from 8.0 to 30.0 J, most preferably in the range from 10.0 to 20.0 J.

The polypropylene composition (PC) preferably has a limonene content, determined by solid phase microextraction (HS-SPME-GC-MS), in the range from 0.10 to 25.0 ppm.

The propylene composition (PC) preferably has a content of mica particles in the range from 0.1 to 3.0 wt.-%, more preferably in the range from 0.3 to 2.0 wt.-%, most preferably in the range from 0.5 to 1.5 wt.-%, relative to the total weight of the polypropylene composition (PC).

The polypropylene composition (PC) preferably has a content of coloured pigment in the range from 0.01 to 1.00 wt.-%, more preferably in the range from 0.01 to 0.50 wt.-%, most preferably in the range from 0.01 to 0.20 wt.-%, relative to the total weight of the polypropylene composition (PC).

The polymeric part of the polypropylene composition (PC) may be characterized according to the CRY STEX QC method using trichlorobenzene (TCB) as a solvent. This method is described below in the determination methods section. The crystalline fraction (CF) contains for the most part the matrix phase and only a small part of the elastomeric phase and the soluble fraction (SF) contains for the most part the elastomeric phase and only a small part of the matrix phase. In some cases, this method results in more useful data, since the crystalline fraction (CF) and the soluble fraction (SF) more accurately correspond to the matrix and elastomeric phases respectively. Due to the differences in the separation methods of xylene extraction and CRYSTEX QC method the properties of XCS/XCI fractions on the one hand and crystalline/soluble (CF/SF) fractions on the other hand are not exactly the same, meaning that the amounts of matrix phase and elastomeric phase can differ as well as the properties.

The polymeric part of the polypropylene composition (PC) preferably has an ethylene content (C2(total)), determined by CRYSTEX QC analysis, in the range from 10.0 to 30.0 wt.-%, more preferably in the range from 17.0 to 29.0 wt.-%, most preferably in the range from 24.0 to 28.0 wt.-%.

The polymeric part of the polypropylene composition (PC) preferably has a soluble fraction (SF) content, determined by CRYSTEX QC analysis, in the range from 25.0 to 45.0 wt.-%, more preferably in the range from 30.0 to 40.0 wt.-%, most preferably in the range from 32.0 to 37.0 wt.-% Said soluble fraction (SF) preferably has an ethylene content (C2(SF)) determined by CRYSTEX QC analysis, in the range from 45.0 to 75.0 wt.-%, more preferably in the range from 50.0 to 72.0 wt.-%, most preferably in the range from 55.0 to 70.0 wt.-%.

Said soluble fraction (SF) preferably has an intrinsic viscosity (iV(SF)), determined by CRYSTEX QC analysis, in the range from 1.00 to 2.40 dL/g, more preferably in the range from 1.30 to 2.30 dL/g, most preferably in the range from 1.60 to 2.20 dL/g.

Said crystalline fraction (CF) preferably has an ethylene content (C2(CF)), determined by CRYSTEX QC analysis, in the range from 0.0 to 10.0 wt.-%, more preferably in the range from 2.0 to 8.0 wt.-%, most preferably in the range from 4.0 to 7.0 wt.-%.

Said crystalline fraction (CF) preferably has an intrinsic viscosity (iV(CF)), determined by CRYSTEX QC analysis, in the range from 1.00 to 2.00 dL/g, more preferably in the range from l. lO to 1.80 dL/g, most preferably in the range from 1.20 to 1.60 dL/g.

It is preferred that the ratio of the intrinsic viscosity of the soluble and crystalline fractions, (iV(SF)/iV(CF)), determined by CRYSTEX QC analysis, is in the range from 1.00 to 2.00, more preferably in the range from 1.20 to 1.80, most preferably in the range from 1.40 to 1.70.

The properties of the individual components (for both the first and second aspects) will now be detailed in the following sections. The heterophasic propylene-ethylene copolymer (HECO)

The heterophasic propylene ethylene copolymer (HECO) is provided in an amount in the range from 20.0 to 50.0 wt.-%, more preferably in the range from 22.0 to 45.0 wt.-%, most preferably in the range from 25.0 to 40.0 wt.-%, relative to the total weight of the polypropylene composition (PC).

The heterophasic propylene ethylene copolymer (HECO) preferably has a melt flow rate (MFR2), determined according to ISO 1133 at 230 °C and 2.16 kg, in the range from 90 to 250 g/ 10 min, more preferably in the range from 93 to 200 g/10 min, most preferably in the range from 95 to 150 g/10 min.

The heterophasic propylene ethylene copolymer (HECO) has an ethylene content (C2(total)), determined by CRYSTEX QC analysis, in the range from 5.0 to 20.0 wt.-%, more preferably in the range from 7.0 to 15.0 wt.-%, most preferably in the range from 8.0 to 11.0 wt.-%.

The heterophasic propylene ethylene copolymer (HECO) preferably has a soluble fraction (SF) content, determined by CRYSTEX QC analysis, in the range from 15.0 to 40.0 wt.-%, more preferably in the range from 18.0 to 30.0 wt.-%, most preferably in the range from 20.0 to 26.0 wt.-%.

The heterophasic propylene ethylene copolymer (HECO) preferably has an ethylene content of the soluble fraction (C2(SF)), determined by CRYSTEX QC analysis, in the range from 25.0 to 45.0 wt.-%, more preferably in the range from 30.0 to 38.0 wt.-%, most preferably in the range from 32.0 to 37.0 wt.-%.

The heterophasic propylene ethylene copolymer (HECO) has an intrinsic viscosity of the soluble fraction (iV(SF)), determined by CRYSTEX QC analysis, in the range from 2.00 to 4.00 dL/g, more preferably in the range from 2.60 to 3.80 dL/g, most preferably in the range from 3.20 to 3.60 dL/g. The heterophasic propylene ethylene copolymer (HECO) preferably has a crystalline fraction (CF) content, determined by CRYSTEX QC analysis, in the range from 60.0 to 85.0 wt.-%, more preferably in the range from 70.0 to 82.0 wt.-%, most preferably in the range from 74.0 to 80.0 wt.-%.

The heterophasic propylene ethylene copolymer (HECO) preferably has an ethylene content of the crystalline fraction (C2(CF)), determined by CRYSTEX QC analysis, in the range from 0.0 to 4.0 wt.-%, more preferably in the range from 0.2 to 2.0 wt.-%, most preferably in the range from 0.5 to 1.5 wt.-%.

The heterophasic propylene ethylene copolymer (HECO) has an intrinsic viscosity of the crystalline fraction (iV(CF)), determined by CRYSTEX QC analysis, in the range from 0.50 to 1.70 dL/g, more preferably in the range from 0.70 to 1.40 dL/g, most preferably in the range from 0.80 to 1.10 dL/g.

It is also preferred that the ratio of the intrinsic viscosity of the soluble and crystalline fractions, (iV(SF)ZiV(CF)), determined by CRYSTEX QC analysis, is in the range from 2.80 to 5.00, more preferably in the range from 3.00 to 4.50, most preferably in the range from 3.20 to 4.00.

The mixed-plastic polypropylene blend (B)

The mixed-plastic polypropylene blend (B) is provided in an amount in the range from 1.0 to 30.0 wt.-%, more preferably in the range from 10.0 to 28.0 wt.-%, most preferably in the range from 15.0 to 25.0 wt.-%, relative to the total weight of the polypropylene composition (PC).

The mixed-plastic polypropylene blend (B) is a polypropylene rich recycled material, meaning that it comprises significantly more polypropylene than polyethylene. Recycled waste streams, which are high in polypropylene can be obtained for example from the automobile industry, particularly as some automobile parts such as bumpers are sources of fairly pure polypropylene material in a recycling stream. Preferably, the polypropylene rich recycled material is obtained from recycled waste by means of plastic recycling processes known in the art. Such recyclates are commercially available, e.g. from Corepla (Italian Consortium for the collection, recovery, recycling of packaging plastic wastes), Resource Plastics Corp. (Brampton, ON), Kruschitz GmbH, Plastics and Recycling (AT), Vogt Plastik GmbH (DE), Mtm Plastics GmbH (DE) etc. Non- exhaustive examples of polypropylene rich recycled materials include: Purpolen®PP (Mtm Plastics GmbH), Axpoly® recycled polypropylene pellets (Axion Ltd) and PolyPropylene Copolymer (BSP Compounds).

During recycling, any reasonable measure will usually be taken for any components other than polyethylene and polypropylene to be reduced/removed as far as the final application or use suggests such measures; however, other components are often present in small amounts.

Other such components include polystyrene (PS), polyamides (PA), polyethylene terephthalate (PET), which are all present in as low an amount as possible, preferably below the detection limit.

The mixed-plastic polypropylene blend (B) has a melt flow (MFR2), determined according to ISO 1133 at 230 °C and 2.16 kg, in the range from 8.0 to 25.0 g/ 10 min, more preferably in the range from 12.0 to 23.0 g/10 min, most preferably in the range from 16.0 to 21.0 g/10 min.

The mixed-plastic polypropylene blend (B) preferably has an ethylene content (C2(total)), determined by CRYSTEX QC analysis, in the range from 2.5 to 10.0 wt.-%, more preferably in the range from 3.0 to 9.0 wt.-%, most preferably in the range from 4.0 to 8.0 wt.-%.

The mixed-plastic polypropylene blend (B) preferably has a has a soluble fraction (SF) content, determined by CRYSTEX QC analysis, in the range from 4.0 to 15.0 wt.-%, more preferably in the range from 6.0 to 14.0 wt.-%, most preferably in the range from 8.0 to 13.0 wt.-%. The mixed-plastic polypropylene blend (B) preferably has a has a crystalline fraction (CF) content, determined by CRYSTEX QC analysis, in the range from 85.0 to 96.0 wt.-%, more preferably in the range from 86.0 to 94.0 wt.-%, most preferably in the range from 87.0 to 92.0 wt.-%.

The mixed-plastic polypropylene blend (B) preferably has an ethylene content of the soluble fraction (C2(SF)), determined by CRYSTEX QC analysis, in the range from 20.0 to 50.0 wt.-%, more preferably in the range from 22.0 to 40.0 wt.-%, most preferably in the range from 24.0 to 35.0 wt.-%.

The mixed-plastic polypropylene blend (B) preferably has an ethylene content of the crystalline fraction (C2(CF)), determined by CRYSTEX QC analysis, in the range from 1.0 to 10.0 wt.-%, more preferably in the range from 2.0 to 8.0 wt.-%, most preferably in the range from 3.0 to 6.0 wt.-%.

The mixed-plastic polypropylene blend (B) preferably has an intrinsic viscosity of the soluble fraction (iV(SF)), determined by CRYSTEX QC analysis, in the range from 1.00 to 2.20 dL/g, more preferably in the range from 1.30 to 2.00 dL/g, most preferably in the range from 1.50 to 1.80 dL/g.

The mixed-plastic polypropylene blend (B) preferably has an intrinsic viscosity of the crystalline fraction (iV(CF)), determined by CRYSTEX QC analysis, in the range from 1.00 to 2.20 dL/g, more preferably in the range from 1.30 to 2.00 dL/g, most preferably in the range from 1.50 to 1.80 dL/g.

The mixed-plastic polypropylene blend (B) preferably has an inorganic residue content, as determined by calcination analysis according to DIN ISO 1172: 1996, of 0.05 to 3.0 wt.-%, more preferably in the range from 0. 10 to 2.0 wt.-%, most preferably in the range from 0.50 to 1.5 wt.-%

The mixed-plastic polypropylene blend (B) preferably originates from post-industrial waste or post-consumer waste, most preferably from post-consumer waste. The mixed-plastic polypropylene blend (B) preferably has a limonene content, determined by solid phase microextraction (HS-SPME-GC-MS), in the range from 0.10 to 100 ppm, more preferably in the range from 1.0 to 70 ppm, most preferably in the range from 5.0 to 30 PPm

The presence of limonene is indicative that the mixed-plastic polypropylene blend (B) originates from post-consumer waste.

Further indications of the recycled-nature of the mixed-plastic polypropylene blend (B) include the presence of other polymers, such as polystyrene and polyamide-6, and the presence of fatty acids.

Accordingly, it is further preferred that the mixed-plastic polypropylene blend (B) comprises one or more of polystyrene, polyamide-6 and fatty acids, preferably comprises each of polystyrene, polyamide-6 and fatty acids.

The mixed-plastic polypropylene blend (B) preferably has a Charpy Notched impact strength at 23 °C, determined according to ISO 179 using 80x 10x4 mm³ test bars injection-moulded in line with ISO 19069-2, in the range from 1.0 to 20.0 kJ/m², more preferably in the range from 2.0 to 15.0 kJ/m², most preferably in the range from 3.0 to 10.0 kJ/m².

The mixed-plastic polypropylene blend (B) preferably has a flexural modulus, determined according to ISO 178 using 80x 10x4 mm³ test bars injection-moulded in line with ISO 19069-2, in the range from 1000 to 1600 MPa, more preferably in the range from 1100 to 1500 MPa, most preferably in the range from 1200 to 1400 MPa.

The mixed-plastic polypropylene blend (B) preferably has a density, determined according to ISO 1183-187, in the range from 890 to 950 kg/m³, more preferably in the range from 900 to 940 kg/m³, most preferably in the range from 910 to 930 kg/m³. The ethylene-octene elastomer (EC)

The ethylene-octene elastomer (EC) is an elastomeric copolymer containing ethylene monomers and 1 -octene comonomers.

The ethylene-octene elastomer (EC) is provided in an amount in the range from 14.0 to 124.0 wt.-%, more preferably in the range from 16.0 to 22.0 wt.-%, most preferably in the range from 18.0 to 20.0 wt.-%, relative to the total weight of the polypropylene composition (PC).

The ethylene-octene elastomer (EC) preferably has a melt flow rate (MFR2), determined according to ISO 1133 at 190 °C and 2.16 kg, in the range from 0.2 to 3.0 g/10 min, more preferably in the range from 0.3 to 2.0 g/10 min, most preferably in the range from 0.4 to 1.5 g/10 min.

The ethylene-octene elastomer (EC) preferably has a density, determined according to ISO 1183-187, in the range from 850 to 870 kg/m³, more preferably in the range from 853 to 867 kg/m³, most preferably in the range from 856 to 864 kg/m³.

The optional propylene homopolymer (h-PP)

If present, the propylene homopolymer (h-PP) is provided in an amount in the range from 0.0 to 10.0 wt.-%, more preferably in the range from 3.0 to 9.0 wt.-%, most preferably in the range from 5.0 to 8.0 wt.-%, relative to the total weight of the polypropylene composition (PC).

Preferably, the propylene homopolymer (h-PP) has a melt flow rate (MFR2), determined according to ISO 1133 at 230 °C and 2.16 kg, in the range from 300 to 2000 g/10 min, more preferably in the range from 600 to 1700 g/10 min, most preferably in the range from 900 to 1400 g/10 min. Preferably, the propylene homopolymer (h-PP) has a melting temperature, determined according to according to ISO 11357, in the range from 150 to 170 °C, more preferably in the range from 153 to 165 °C, most preferably in the range from 156 to 160 °C.

The inorganic filler (F) other than mica

The inorganic filler (F) is provided in an amount in the range from 5.0 to 17.0 wt.-%, more preferably in the range from 10.0 to 17.0 wt.-%, most preferably in the range from 12.0 to 16.0 wt.-%, relative to the total weight of the polypropylene composition (PC).

The inorganic filler (F) preferably has a median diameter (dso), determined according to ISO 13320-1 (laser), in the range from 2.0 to 20.0 pm, more preferably in the range from 3.0 to 16.0 pm, most preferably in the range from 4.0 to 12.0 pm.

The inorganic filler (F) preferably has a top cut diameter (dgs), determined according to ISO 13320-1 (laser), in the range from 5.0 to 50 pm, more preferably in the range from 7.0 to 45 pm, most preferably in the range from 9.0 to 40 pm.

The inorganic filler (F) preferably has a median diameter (dso), determined according to ISO 13317-3 (sedigraph), in the range from 0.7 to 3.0 pm, more preferably in the range from 1.0 to 2.6 pm, most preferably in the range from 1.2 to 2.2 pm.

The inorganic filler (F) preferably has a top cut diameter (dgs), determined according to ISO 13317-3 (sedigraph), in the range from 2.0 to 20.0 pm, more preferably in the range from 3.0 to 16.0 pm, most preferably in the range from 3.5 to 12.0 pm.

In the broadest sense, the inorganic filler may be any filler other than mica. It is preferred that the inorganic filler is selected from the group containing talc, calcium carbonate, barium sulfate, and mixtures thereof.

Most preferably, the inorganic filler (F) is talc. The mica-containing pigment masterbatch (MPM)

The mica-containing pigment masterbatch (MPM) is provided in an amount in the range from 1.0 to 5.0 wt.-%, more preferably in the range from 1.5 to 5.0 wt.-%, most preferably in the range from 2.0 to 5.0 wt.-%, relative to the total weight of the polypropylene composition (PC).

The mica-containing pigment masterbatch comprises mica, at least one coloured pigment, and a carrier polymer.

The mica-containing pigment masterbatch (MPM) preferably has a content of mica particles in the range from 10 to 50 wt.-%, more preferably in the range from 20 to 40 wt.-%, most preferably in the range from 25 to 35 wt.-%, relative to the total weight of the micacontaining pigment masterbatch (MPM).

The mica-containing pigment masterbatch (MPM) preferably has a content of coloured pigment in the range from 0.50 to 20.0 wt.-%, more preferably in the range from 0.80 to 10.0 wt.-%, most preferably in the range from 1.00 to 2.00 wt.-%, relative to the total weight of the mica-containing pigment masterbatch (MPM).

The at least one coloured pigments are preferably selected from black pigments, most preferably the coloured pigment is carbon black.

The carrier polymer is preferably a polyethylene or a polypropylene, more preferably a polyethylene. It is particularly preferred that the carrier polymer is a low -density polyethylene (LDPE).

The further additives (A)

The further additives (A) are provided in an amount in the range from 0.2 to 5.0 wt.-%. The skilled practitioner would be able to select suitable additives that are well known in the art. The additives (A) are preferably selected from pigments, antioxidants, UV-stabilizers, antiscratch agents, mold release agents, acid scavengers, lubricants, anti-static agents, and mixtures thereof.

It is understood that the content of additives (A), given with respect to the total weight of the polypropylene composition (PC), includes any carrier polymers used to introduce the additives to said polypropylene composition (PC), i.e. masterbatch carrier polymers. An example of such a carrier polymer would be a polypropylene homopolymer in the form of powder.

Article

In a third aspect, the present invention is directed to an article, preferably an injection- moulded article, comprising the polypropylene composition according to any one of the preceding claims in an amount of at least 95 wt.-%, more preferably at least 98 wt.-%, most preferably at least 99 wt.-%.

Preferably, the article, more preferably the injection-moulded article, is an automotive exterior article, more preferably selected from the group consisting of bumpers, side trims, step assists, body panels, and spoilers.

Process

In a fourth aspect, the present invention is directed to a process for producing articles according to the third aspect, comprising the steps of a) blending a heterophasic propylene -ethylene copolymer (HECO), a mixed-plastic polypropylene blend (B), an ethylene -octene elastomer (EC), an inorganic filler (F), further additives (A), and optionally a propylene homopolymer (h-PP), thereby obtaining a polymer composition (PE); and b) injection moulding the polymer composition (PE) to form an injection-moulded article, wherein a mica-containing pigment masterbatch (MPM) is added during the blending of step a) or during the injection moulding of step b).

The choice of whether to add the mica-containing pigment masterbatch (MPM) controls the size of the mica in the final injection-moulded article. Each compounding/extruding step that the mica is exposed to reduces the size of the mica particles in the final injection-moulded article, thus it may be preferably to reduce the number of compounding/extruding steps that the mica is exposed to by opting to add the mica-containing pigment masterbatch (MPM) during step b) rather than step a). Conversely, if a smaller particle size is desired, then it would be preferable to add the mica-containing pigment masterbatch (MPM) during step a).

In one embodiment, the process of the fourth aspect comprises the steps of: a) blending a heterophasic propylene -ethylene copolymer (HECO), a mixed-plastic polypropylene blend (B), a mica-containing pigment masterbatch (MPM), an ethylene -octene elastomer (EC), an inorganic filler (F), further additives (A), and optionally a propylene homopolymer (h-PP), thereby obtaining the polypropylene composition (PC) of the second aspect; b) injection moulding the polypropylene composition (PC) to form an injection- moulded article.

This embodiment is preferred in the case that a small mica particle size is desired in the final injection-moulded article.

In an alternative embodiment, the process of the fourth aspect comprises the steps of: a) blending a heterophasic propylene -ethylene copolymer (HECO), a mixed-plastic polypropylene blend (B), an ethylene -octene elastomer (EC), an inorganic filler (F), further additives (A) and optionally a propylene homopolymer (h-PP), thereby obtaining a polymer composition (PE) b) injection moulding the polymer composition (PE) with a mica-containing masterbatch (MPM) to form an injection-moulded article. This embodiment is preferred in the case that a large mica particle size is desired in the final injection-moulded article.

The polypropylene composition (PC), heterophasic propylene-ethylene copolymer (HECO), the mixed heterophasic propylene-ethylene copolymer (HECO), the mixed-plastic polypropylene blend (B), the ethylene-octene elastomer (EC), the inorganic filler (F), the mica-containing masterbatch (MPM) the further additives (A), and the optional propylene homopolymer (h-PP) are as described for the second aspect. All preferred features and fallback positions given for the components/composition of the second aspect apply mutatis mutandis to the components/composition of the process of the final aspect.

E X A M P L E S

1. Measurement methods

The following definitions of terms and determination methods apply for the above general description of the invention including the claims as well as to the below examples unless otherwise defined.

Quantification of microstructure by NMR spectroscopy

Quantitative nuclear-magnetic resonance (NMR) spectroscopy was used to quantify the comonomer and regiodefect content of the polymers.

Quantitative ¹³C { ¹ H } NMR spectra were recorded in the solution-state using a Broker A vance III 400 NMR spectrometer operating at 400.15 and 100.62 MHz for ’H and ¹³C respectively. All spectra were recorded using a ¹³C optimised 10 mm extended temperature probehead at 125°C using nitrogen gas for all pneumatics. Approximately 200 mg of material was dissolved in approximately 3 ml of 7,2-tetrachloroethane- 2 (TCE-t/2) along with chromium-(III)-acetylacetonate (Cr(acac)3) resulting in a 65 mM solution of relaxation agent in solvent {singh09}. To ensure a homogenous solution, after initial sample preparation in a heat block, the NMR tube was further heated in a rotatary oven for at least 1 hour. Upon insertion into the magnet the tube was spun at 10 Hz. This setup was chosen primarily for the high resolution and quantitatively needed for accurate ethylene content quantification. Standard single-pulse excitation was employed without NOE, using an optimised tip angle, 1 s recycle delay and a bi-level WALTZ 16 decoupling scheme {zhou07,busico07}. A total of 6144 (6k) transients were acquired per spectra.

Quantitative ¹³C{³H} NMR spectra were processed, integrated and relevant quantitative properties determined from the integrals using proprietary computer programs. All chemical shifts were indirectly referenced to the central methylene group of the ethylene block (EEE) at 30.00 ppm using the chemical shift of the solvent. This approach allowed comparable referencing even when this structural unit was not present.

Characteristic signals corresponding to the incorporation of ethylene were observed {wangOO, cheng84, randall89}. The comonomer fraction was quantified using the method of Wang et. al. {wangOO} through integration of multiple signals across the whole spectral region in the ¹³C{¹H} spectra. This method was chosen for its robust nature and ability to account for the presence of regiodefects when needed. Integral regions were slightly adjusted to increase applicability across the whole range of encountered comonomer contents.

For systems where only isolated ethylene in PPEPP sequences was observed the method of Wang et. al. was modified to reduce the influence of non-zero integrals of sites that are known to be not present. This approach reduced the overestimation of ethylene content for such systems and was achieved by reduction of the number of sites used to determine the absolute ethylene content. Through the use of this set of sites the corresponding integral equation becomes _PS = IA + (0.5 * I_B)

PT = ID + IF + ID p = (ps + pr) / 2 e = 0.5 * (I_H + (0.5 * I_B)) fE = e / (e + p) using the same notation used in the article of Wang et. al. {wangOO}.

The mole percent comonomer incorporation was calculated from the mole fraction:

E [mol%] = 100 * fE

The weight percent comonomer incorporation was calculated from the mole fraction:

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

Characteristic signals corresponding to regio defects were observed {resconiOO, wangOO}. The presence of isolated 2,1-erythro regio defects was indicated by the presence of the two methyl sites at 17.7 and 17.2 ppm and confirmed by other characteristic sites. The presence of 2,1 regio defect adjacent an ethylene unit was indicated by the two inequivalent Sa signals at 34.9 ppm and 34.7 ppm respectively and the Tyy at 34.1 ppm.

The amount of isolated 2,1-erythro regio defects (P2ie isolated) was quantified using the average integral of the two characteristic methyl sites at 17.7 (I_es) and 17.4 (I_ee) ppm respectively: P21e isolated ^— ( Ie6 + Ie8 ) / 2

The amount of 2, 1 regio defect adjacent to ethylene (PE2I) was quantified using the methine site at 34.1 ppm (IT_YY):

PE21 = IT_YY The total amount of propene (Ptotai) was quantified based on the methyl region (lens) between 23.0 and 19.9 ppm with correction undertaken for sites included in this region not related to propene insertion. The methyl group P_w resulting from 2,1 regio defect adjacent to ethylene is already present in lens: Ptotai ^— IcH3 + 2 * ?21e isolated

The isolated 2,1-erythro regio defects (P2ie isolated) is multiplied by 2 to take into account the two (2) propene units in the 2, 1-erythro regio defects.

The mole percent of isolated 2,1-erythro regio defects was quantified with respect to all propene:

[2 le] mol% = 100 * P₂le isolated / Ptotai

The mole percent of 2,1 regio defects adjacent to ethylene was quantified with respect to all propene:

[E21] mol% = 100 * P_E2i / Ptotai

The total amount of 2,1 defects was quantified as following:

[21] mol% = [21e] + [E21]

Characteristic signals corresponding to other types of regio defects (2,1-threo, 3,1 insertion) were not observed {resconiOO}. zhou07 Zhou, Z., Kuemmerle, R., Qiu, X., Redwine, D., Cong, R., Taha, A., Baugh, D. Winniford, B., J. Mag. Reson. 187 (2007) 225 busico07 Busico, V., Carbonniere, P., Cipullo, R., Pellecchia, R., Severn, J., Talarico, G., Macromol. Rapid Commun. 2007, 28, 1128 resconiOO Resconi, L., Cavallo, L., Fait, A., Piemontesi, F., Chem. Rev. 2000, 100, 1253 wangOO Wang, W-J., Zhu, S., Macromolecules 33 (2000), 1157 cheng84 Cheng, H. N., Macromolecules 17 (1984), 1950 singh09 Singh, G., Kothari, A., Gupta, V., Polymer Testing 28 5 (2009), 475 randall89 Randall, J. Macromol. Sci., Rev. Macromol. Chem. Phys. 1989, C29, 201. CRYSTEX QC analysis

Crystalline and soluble fractions method

The crystalline (CF) and soluble fractions (SF) of the polypropylene (PP) compositions as well as the comonomer content and intrinsic viscosities of the respective fractions were analyzed by use of the CRYSTEX instrument, Polymer Char (Valencia, Spain). Details of the technique and the method can be found in literature (Ljiljana Jeremie, Andreas Albrecht, Martina Sandholzer & Markus Gahleitner (2020) Rapid characterization of high-impact ethylenepropylene copolymer composition by cry stallization extraction separation: comparability to standard separation methods, International Journal of Polymer Analysis and Characterization, 25:8, 581-596)

The crystalline and amorphous fractions are separated through temperature cycles of dissolution at 160 °C, crystallization at 40 °C and re-dissolution in 1,2,4-trichlorobenzene at 160 °C. Quantification of SF and CF and determination of ethylene content (C2) are achieved by means of an integrated infrared detector (IR4) and for the determination of the intrinsic viscosity (IV) an online 2-capillary viscometer is used.

The IR4 detector is a multiple wavelength detector measuring IR absorbance at two different bands (CH3 stretching vibration (centred at app. 2960 cm ¹) and the CH stretching vibration (2700-3000 cm ¹) that are serving for the determination of the concentration and the Ethylene content in Ethylene-Propylene copolymers. The IR4 detector is calibrated with series of 8 EP copolymers with known Ethylene content in the range of 2 wt.-% to 69 wt.-% (determined by ¹³C-NMR) and each at various concentrations, in the range of 2 and 13mg/ml. To encounter for both features, concentration and ethylene content at the same time for various polymer concentrations expected during Crystex analyses the following calibration equations were applied:

Cone = a + b*Abs(CH) + c*(Abs(CH))² + d*Abs(CH₃) + e*(Abs(CH₃)² + f*Abs(CH)*Abs(CH₃) (Equation 1)

CH₃/1000C = a + b*Abs(CH) + c* Abs(CH₃) + d * (Abs(CH₃)/Abs(CH)) + e * (Abs(CH₃)/Abs(CH))² (Equation 2) The constants a to e for equation 1 and a to f for equation 2 were determined by using least square regression analysis.

The CH3/IOOOC is converted to the ethylene content in wt.-% using following relationship:

Wt.-% (Ethylene in EP Copolymers) = 100 - CH3/IOOOTC * 0.3 (Equation 3)

Amounts of Soluble Fraction (SF) and Crystalline Fraction (CF) are correlated through the XS calibration to the “Xylene Cold Soluble” (XCS) quantity and respectively Xylene Cold Insoluble (XCI) fractions, determined according to standard gravimetric method as per ISO16152. XS calibration is achieved by testing various EP copolymers with XS content in the range 2-31 wt.-%. The determined XS calibration is linear:

Wt.-% XS = 1,01* Wt.-% SF (Equation 4)

Intrinsic viscosity (IV) of the parent EP copolymer and its soluble and crystalline fractions are determined with a use of an online 2-capillary viscometer and are correlated to corresponding IV’ s determined by standard method in decalin according to ISO 1628-3. Calibration is achieved with various EP PP copolymers with IV = 2-4 dL/g. The determined calibration curve is linear:

IV (dL/g) = a* Vsp/c (equation 5)

The samples to be analyzed are weighed out in concentrations of lOmg/ml to 20mg/ml. To avoid injecting possible gels and/or polymers which do not dissolve in TCB at 160 °C, like PET and PA, the weighed out sample was packed into a stainless steel mesh MW 0, 077/D 0,05mmm.

After automated filling of the vial with 1,2,4-TCB containing 250 mg/1 2,6-tert-butyl-4- methylphenol (BHT) as antioxidant, the sample is dissolved at 160 °C until complete dissolution is achieved, usually for 60 min, with constant stirring of 400rpm. To avoid sample degradation, the polymer solution is blanketed with the N2 atmosphere during dissolution. A defined volume of the sample solution is injected into the column filled with inert support where the crystallization of the sample and separation of the soluble fraction from the crystalline part is taking place. This process is repeated two times. During the first injection the whole sample is measured at high temperature, determining the IV [dl/g] and the C2[wt.%] of the PP composition. During the second injection the soluble fraction (at low temperature) and the crystalline fraction (at high temperature) with the crystallization cycle are measured (wt.-% SF, wt.-% C2, IV).

Melt Flow Rate

The melt flow rate (MFR) is determined according to ISO 1133 and is indicated in g/10 min. The MFR is an indication of the flowability, and hence the processability, of the polymer. The higher the melt flow rate, the lower the viscosity of the polymer. The MFR2 of polypropylene is determined at a temperature of 230 °C and a load of 2.16 kg.

Density:

The density is measured according to ISO 1183-187. Sample preparation is done by compression moulding in accordance with ISO 1872-2:2007.

The xylene soluble fraction at room temperature (XCS, wt.-%): The amount of the polymer soluble in xylene is determined at 25 °C according to ISO 16152; 5^th edition; 2005- 07-01.

DSC analysis, melting temperature (T_m) and heat of fusion (Hf), crystallization temperature (T_c) and heat of crystallization (H_c): measured with a TA Instrument Q200 differential scanning calorimetry (DSC) on 5 to 7 mg samples. DSC is run according to ISO 11357 / part 3 /method C2 in a heat / cool / heat cycle with a scan rate of 10 °C/min in the temperature range of -30 to +225 °C. Crystallization temperature (T_c) and crystallization enthalpy (H_c) are determined from the cooling step, while melting temperature (T_m) and melting enthalpy (H_m) are determined from the second heating step.

The Flexural Modulus is determined according to ISO 178 method A (3-point bending test) on 80 mm * 10 mm x 4 mm specimens. Following the standard, a test speed of 2 mm/min and a span length of 16 times the thickness was used. The testing temperature was 23±2 ° C. Injection moulding was carried out according to ISO 19069-2 using a melt temperature of 230 °C for all materials irrespective of material melt flow rate.

Notched impact strength (NIS)

The Charpy notched impact strength (NIS) is measured according to ISO 179 leA at +23 °C or -20 °C, using injection moulded bar test specimens of 80x 10x4 mm³ prepared in accordance with ISO 19069-2 using a melt temperature of 230 °C for all materials irrespective of material melt flow rate.

Average particle size (diameter) 50 and top cut 95

The particle size definitions are calculated from the particle size distribution [mass percent] as determined by two different methods:

Laser diffraction method, using Laser Mastersizer, according to ISO 13320-1.

Sedigraph method, i.e. gravitational liquid sedimentation, according to ISO 13317-3.

The dso is defined as the median diameter, whilst dgs is the diameter at the 95^th percentile, as observed from the particle size distribution.

Inorganic residues and carbon black determination

Inorganic residues are quantified according to DIN ISO 1172: 1996 using a Perkin Elmer TGA 8000. Approximately 10-20 mg of material was placed in a platinum pan. The temperature was equilibrated at 50 °C for 10 minutes, and afterwards raised to 950 °C under nitrogen at a heating rate of 20 °C/min. The ash content was evaluated as the weight % at 850 °C.

Afterwards the temperature was lowered to 300 °C at 20 °C/min, gas switched to oxygen, and the temperature was raised again to 900 °C. The weight loss in this final step was assigned to carbon black. Fourier transform (FT) infrared (IR) spectroscopy in transmission mode for identification of mica in samples of MPM (mica-containing pigment masterbatch).

The FTIR spectrum was recorded in the solid-state using a Bruker Vertex 70 FTIR spectrometer. Spectra were recorded on 25x25 mm square films of 30 pm thickness prepared by compression moulding at 190°C and 100 bar of pressure for 30 seconds. The film was cooled down by using a room temperature press for additional 30 seconds.

Standard transmission FTIR spectroscopy was employed using a spectral range of 4000-400 cm ¹, an aperture of 6 mm, a spectral resolution of 2 cm ¹, 16 background scans, 16 spectrum scans, an interferogram zero filling factor of 32 and Norton Beer strong apodisation.

Identification of mica was done by assigning the characteristic bands of mica from literature [B. B. Zviagina et. al. Minerals 2020, 10(2), 153; and L. Vaculikova et. al. Acta Geodyn. Geomater. 2005, Vol 2, No.2 (138), 167-175] and SpectraBaseTM, Wiley. Based on the information available in these public domains, we can assign the following bands centered around 3620 cm'¹ (O-H stretching vibration), 1008 cm'¹ (Si-0 stretching vibration), 529 cm'¹ (Si-O-Al bending vibration), and 473 cm'¹ (Si- O-Si bending) as characteristic bands for the presence of Mica.

Limonene detection

The determination of limonene is based on a static headspace (HS) approach. This analysis uses a combination of a HS sampler with a gas chromatograph (GC) and a mass spectrometer (MS) for screening purposes.

Samples were delivered to the lab in sealed aluminium-coated polyethylene (PE) bags. Prior to the analysis, samples were cryo-milled, a portion of 2.000 ± 0.100 g was weighed in a 20 ml HS vial and tightly closed. For every sample, a double determination was performed. HS/GC/MS parameters

• HS parameters (Agilent G1888 Headspace Sampler)

Vial equilibration time: 120 min (sample), 5 min (standard)

Oven temperature: 100 °C (sample), 200 °C (standard)

Loop temperature: 110 °C (sample), 205 °C (standard)

Transfer line temperature: 120 °C (sample), 210 °C (standard)

Low shaking

GC parameters (Agilent 7890A GC System) Column: ZB-WAX 7HG-G007-22

(30 m x 250 pm x 1 pm)

Carrier gas: Helium 5.0

Flow: 2 ml/min

Split: 5: 1

GC oven program: 35 °C for 0.1 min

10 °C/min until 250 °C

250 °C for 1 min

• MS parameters (Agilent 5975C inert XL MSD)

Acquisition mode: Scan

Scan parameters:

Low mass: 20

High mass: 200

Threshold: 10

• Software/Data evaluation

MSD ChemStation E.02.02.1431

MassHunter GC/MS Acquisition B.07.05.2479 AMDIS GC/MS Analysis Version 2.71 NIST/EPA/NIH Mass Spectral Library (2011 version)

NIST Mass Spectral Search Program Version 2.0 g

• AMDIS deconvolution parameters

Minimum match factor: 80

Threshold: Low

Scan direction: High to Low

Data file format: Agilent files

Instrument type: Quadrupole

Component width: 20

Adjacent peak subtraction: Two

Resolution: High

Sensitivity: Very high

Shape requirements: Medium Solvent tailing : 91 m/z

Column bleed: 207 m/z

Min. model peaks: 2

Min. S/N: 10

5 Min. certain peaks: 0.5

• MSD ChemStation integration parameters

Integrator: ChemStation

Initial area reject: 0

Initial peak width: 0.005

10 Shoulder detection: off

Initial thre shold : 10.5

In this study, the statement “below the limit of detection (< LOD)” describes a condition where either the match factor is below 80 (AMDIS) or the signal to noise ratio (Pk-pk S/N = Corrected signal/Pk-pk noise, MSD ChemStation signal to noise report) of the peak in the

15 sample run is below 3. The results refer solely to the measured samples, time of measurement and the applied parameters.

Standard solutions

For a positive identification and comparison with the (lowest) odour detection thresholds (ODT), a limonene standard was used.

20 For the HS/GC/MS analysis, 5 pl of the respective standard was injected in a 20 ml HS vial, tightly closed and measured.

Assuming full vaporisation of the standard substance, the concentration limonene in the HS c_G was estimated as listed in Table 1.

Table 1: Calibration standard and ODT

25

Data evaluation

The concentration of an analyte in the HS c_G is calculated by considering the substance amount m_G and the available HS volume V_G (Equation 1).

Equation 1

To estimate the concentration of an analyte in the HS above a polymer sample, the response factor, Rfo a one-point calibration is required (Equation 2). By integrating the extracted ion chromatogram (EIC), the peak area is obtained for the analyte. The corresponding target ion is listed in Table 1.

R f ₌ _ -

■* Peak rc

Equation 2

The concentration of an analyte in the HS above a polymer sample, _c^^ample i_s calculated by multiplying the response factor with the EIC peak area of the sample (Equation 3).

Cg“^mp(e [mg/m³] = Rf * Peak area^Samp(e

Equation 3

Additionally, the odour relevance of an analyte in the HS above a polymer sample is estimated by the odour activity value (OAV). Therefore, the concentration of an analyte in the HS above a polymer sample _c^^ample is compared with the (lowest) odour detection threshold (ODT) found in literature (Equation 4) [1], A value above 1 indicates the relevance of an analyte to the odour at the given HS temperature.

Equation 4

Considerations and limitations

It must be considered that the ODT for some substances is below the detection limit (LOD) of the method. Therefore, components below the LOD might be missed although still relevant to the overall odour.

The OAV is based on the assumption that the HS parameters are somewhat relatable to the measurement conditions of an ODT determination. Of course, this is not fully applicable because temperature settings of 100 °C are not necessarily chosen for such experiments and have therefore limited practical value. Nevertheless, this approach can at least indicate the odour relevance of the defined marker substances.

References

[1] Van Gemert L. J., Odour Thresholds: Compilations of odour threshold values in air, water and other media, Utrecht, Oliemans Punter & Partners BV, 2011.

Puncture energy and Energy to max Force

Puncture energy and Energy to max Force were determined on plaques with dimensions 60 x 60 x 3 mm³ machined from injection-molded plaques using an instrumented falling weight impact testing according to ISO 6603-2. The test was performed at either 23 °C or -30 °C (as indicated) with a lubricated tip with a diameter of 20 mm and impact velocity of 4.4 mm/s. Six specimens were tested for each sample and the resulting six force-deflection curves were used to calculate the mean value for energy to maximum force and puncture energy. In addition, impact failure type was evaluated. ISO6603-2 defines the following impact failure types; the number in brackets was assigned to calculate a numeric value for impact failure (mean value derived from six tested samples):

YD yielding (zero slope at maximum force) followed by deep drawing (1)

YS yielding (zero slope at maximum force) followed by (at least partially) stable cracking

(2)

YU yielding (zero slope at maximum force) followed by unstable cracking (3)

NY no yielding (4)

2. Examples

2.1 Synthesis of heterophasic propylene-ethylene copolymers (HECOs)

Catalyst for HECO 1

The catalyst used in the polymerisation processes was the commercial ZN 180M of Basell with triethyl-aluminium (TEA) as co-catalyst and dicyclo pentyl dimethoxy silane (donor D) as donor.

Preparation of the catalyst and polymerization for HECO2

For the polymerization process of HECO2 a Ziegler-Natta type catalyst as used in for the inventive examples of WO2016/066446 Al and prepolymerized with vinylcyclohexane to achieve nucleation with poly(vinylcycloxehane) was used.

Nucleation by prepolymerization with vinylcyclohexane is described in EP290256 Bl and EP2960279B1 in detail.

The catalyst system defined above was used in combination with thriethyl-aluminium (TEAL) as co-catalyst and dicyclopenta dienyl-dimethoxy silane (Donor D) as external donor.

Preparation of the catalyst for HECO3

First, 0. 1 mol of MgCT x 3 EtOH was suspended under inert conditions in 250 ml of decane in a reactor at atmospheric pressure. The solution was cooled to the temperature of-15°C and 300 ml of cold TiCL was added while maintaining the temperature at said level. Then, 10 the temperature of the slurry was increased slowly to 20°C. At this temperature, 0.02 mol of dioctylphthalate (DOP) was added to the slurry. After the addition of the phthalate, the temperature was raised to 135°C during 90 minutes and the slurry was allowed to stand for 60 minutes. Then, another 300 ml of TiCL was added and the temperature was kept at 135°C for 120 minutes. After this, the catalyst was filtered from the liquid and washed six 15 times with 300 ml heptane at 80°C. Then, the solid catalyst component was filtered and dried. Catalyst and its preparation concept is described in general e.g. in patent publications EP 491566, EP 591224 and EP 586390. The catalyst was further modified (VCH modification of the catalyst). 35 ml of mineral oil (Paraffmum Liquidum PL68) was added to a 125 ml stainless steel reactor followed by 0.82 20 g of triethyl aluminum (TEAL) and 0.33 g of dicyclopentyl dimethoxy silane (donor D) under inert conditions at room temperature. After 10 minutes 5.0 g of the catalyst prepared above (Ti content 1.4 wt.-%) was added and after additionally 20 minutes 5.0 g of vinylcyclohexane (VCH) was added. The temperature was increased to +60°C during 30 minutes and was kept there for 20 hours. Finally, the temperature was decreased to +20°C 25 and the concentration of unreacted VCH in the oil/catalyst mixture was analysed and was found to be 200 ppm weight

The subsequent polymerization has been effected under the following conditions.

Table 1 Polymerization conditions for the HECOs

The heterophasic copolymers HEC01, HEC02, and HEC03 were compounded in a corotating twin-screw extruder Coperion ZSK 47 at 220 °C with 0.15 wt.-% antioxidant (Irganox B215FF from BASF AG, Germany; this is a l:2-mixture of Pentaerythrityl-tetrakis(3-(3’,5’- di-tert. butyl-4-hydroxyphenyl)-propionate, CAS-no. 6683-19-8, and Tris (2,4-di-t- butylphenyl) phosphite, CAS-no. 31570-04-4); 0.05 wt.-% of Ca-stearate (CAS-no.1592-23- 0, commercially available from Faci, Italy).

2.2 Mixed-plastic polypropylene blends (B)

The properties of the mixed-plastic polypropylene blends (Bl and B2) are given in Table 2.

Table 2 Properties of mixed-plastic polypropylene blends (Bl and B2)

The mixed-plastic polypropylene blends (Bl and B2) further comprise minor amounts of polystyrene, polyamide-6 and fatty acids.

2.3 Compounding of Inventive, Comparative and Reference Compositions

The inventive and comparative compositions were prepared based on the recipes indicated in Table 3 by compounding in a co-rotating twin-screw extruder Coperion ZSK 40 at 220 °C. For RE1, CE1, RE2, IE4 and IE5, all components are added during this compounding step, whilst for CE2, IE1, IE2, and IE3, the mica-containing pigment masterbatch was added in a separate step during the injection moulding of the specimens for mechanical testing. Adding in a separate step reduces the number of compounding/extruding steps that the mica is exposed to, helping to maintain a larger mica particle size in the final article/specimen.

In addition to the HECOs and the mixed-plastic polypropylene blends described above, the following commercially available components were also employed:

ECI an elastomeric ethylene-butene copolymer with a trade name of Engage HM7487, commercially available from Dow Chemicals (USA), having an MFR2 (190 °C) of 0.27 g/10 min and a density of 860 kg/m³.

EC2 an elastomeric ethyl ene-octene copolymer with a trade name of

Engage 8180, commercially available from Dow Chemicals (USA), having an MFR2 (190 °C) of 0.6 g/10 min and a density of 863 kg/m³.

EC3 an elastomeric ethylene-octene copolymer with a trade name of

Engage 8842, commercially available from Dow Chemicals (USA), having an MFR2 (190 °C) of 1.0 g/10 min and a density of 857 kg/m³. h-PP a commercial propylene homopolymer HL712FB, commercially available from Borealis AG (Austria), having MFR₂ (230 °C) of 1200 g/lOmin and a Tm of 158 °C.

Fl talc with a trade name of Luzenac HAR T84, commercially available from Imerys (France), with median diameter dso of 2.0 pm and top cut diameter dgs of 11.3 pm, as determined by Sedigraph analysis (ISO 13317-3), and median diameter dso of 10.5 pm and top cut diameter dgs of 34.2 pm, as determined by laser diffraction (ISO 13320-1), with a DL/DS of 5.25. F2 talc with a trade name of Jetfine 3CA, commercially available from Imerys (France), with median diameter dso of 1.3 pm and top cut diameter dgs of 3.9 pm, as determined by Sedigraph analysis (ISO 13317-3), and median diameter dso of 4.4 pm and top cut diameter dgs of 9.9 pm, as determined by laser diffraction (ISO 13320-1), with a DL/DS of 3.38.

MPM mica-containing pigment masterbatch containing 30 wt.-% of mica and 1.5 wt.-% carbon black, with the remaining weight being an LDPE masterbatch carrier.

A Additive masterbatch containing (relative to the total weight of the total composition, rather than the total weight of the masterbatch) 1.01 wt.-% of a masterbatch carrier propylene homopolymer with a trade name of HC001 A, commercially available from Borealis AG (Austria), 0. 12 wt.-% of an antistatic agent with a trade name of Dimodan HP FF (CAS- no. 97593-29-8), commercially available from Danisco (Denmark), 0.20 wt.-% of a slip agent with a trade name of Finawax-0, commercially available from Fine Organics (India), 0.20 wt.-% of calcium stearate (CAS-no. 1592-23-0), commercially available from Baerlocher (Germany) under the trade name Ceasit FI, 0.40 wt.-% of a UV stabilizer with a reade name of Uvasorb HA19 (CAS-no. 106990-43-6), commercially available from 3 V (USA), 0.20 wt.-% of a UV stabilizer blend with a trade name of Sabostab UV228, commercially available from Sabo S.p.A (Italy), 0.20 wt.-% of an antioxidant with a trade name of Irganox 1076 (CAS-no. 2082-79-3), commercially available from BASF AG (Germany), and 0.07 wt.-% of an antioxidant with a trade name of Irgafos 168 (CAS-no. 31570-04-4), commercially available from BASF AG (Germany). Table 3 Recipes for inventive and comparative examples

The properties of the inventive and comparative compositions are given in Table 4. As can be seen from Table 4, the inventive examples IE1 to IE5 maintain an acceptable balance of stiffness and impact properties at room temperature relative to RE2 (i.e. an analogous composition without the mica-containing pigmented masterbatch (MPM)). On the other hand. CE1 and CE2 have notably reduced puncture energy at room temperature relative to RE1. More critically, the low temperature (-30 °C) energy to max force and puncture energy are much better for IE1 to IE5 versus CE1 and CE2. The effect of the invention has been verified for methods wherein the MPM is added during injection moulding (CE2 and IE1 to IE3) as well as methods wherein the MPM is added during the compounding (CE1, IE4 and IE5), demonstrating the flexibility of the present invention when differing snowflake visual effects are desired. Table 4 Properties of the inventive and comparative compositions

Claims

C L A I M S

1. A polypropylene composition (PC) being a mixed-plastic polypropylene blend, wherein the polypropylene composition (PC) has: a) a melt flow rate (MFR2), determined according to ISO 1133 at 230 °C and 2.16 kg, in the range from 5.0 to 40.0 g/10 min; b) an energy to max force at -30 °C, measured according to ISO 6603-2 using injection-moulded plaques of 60 x 60 x 3 mm and a test speed of 4.4 m/s, in the range from 6.0 to 50.0 J; c) a puncture energy at -30 °C, measured according to ISO 6603-2 using injection-moulded plaques of 60 x 60 x 3 mm and a test speed of 4.4 m/s, in the range from 6.0 to 50.0 J; and d) a limonene content, determined by solid phase microextraction (HS-SPME- GC-MS), in the range from 0.10 to 25.0 ppm; e) a content of mica particles in the range from 0. 1 to 3.0 wt.-%, relative to the total weight of the polypropylene composition; and f) a content of coloured pigment in the range from 0.01 to 1.00 wt.-%, relative to the total weight of the polypropylene composition; wherein the polymeric part of said polypropylene composition (PC) has: i) a crystalline fraction (CF) having an intrinsic viscosity (iV(CF)), determined by CRYSTEX QC analysis, in the range from 1.00 to 2.00 dL/g; ii) a soluble fraction (SF) having an intrinsic viscosity (iV(SF)), determined by CRYSTEX QC analysis, in the range from 1.00 to 2.40 dL/g; and iii) an intrinsic viscosity ratio (iV(SF)/iV(CF)), determined by CRYSTEX QC analysis, in the range from 1.00 to 2.00.

2. The polypropylene composition (PC) according to claim 1, wherein the soluble fraction (SF) content of the polymeric part of the polypropylene composition (PC), determined by CRYSTEX QC analysis, is in the range from 25.0 to 45.0 wt.-% and the crystalline fraction (CF) content of the polymeric part of the polypropylene composition (PC), determined by CRYSTEX QC analysis, is in the range from 55.0 to 75.0 wt.-%, with both contents expressed as a wt.-% relative to the total weight of the polymeric part of the polypropylene composition (PC).

3. The polypropylene composition (PC) according to claim 1 or claim 2, wherein the crystalline fraction (CF) has an ethylene content (C2(CF)), determined by CRYSTEX QC analysis, in the range from 0.0 to 10.0 wt.-%, and/or the soluble fraction (SF) has an ethylene content (C2(SF)), determined by CRYSTEX QC analysis, in the range from 45.0 to 75.0 wt.-%.

4. The polypropylene composition (PC) according to any one of the preceding claims, having an ethylene content (C2(total)), determined by CRYSTEX QC analysis, in the range from 10.0 to 30.0 wt.-%.

5. The polypropylene composition (PC) according to any one of the preceding claims, having one or more, preferably all, of the following properties: a) an energy to max force at 23 °C, measured according to ISO 6603-2 using injection-moulded plaques of 60 x 60 x 3 mm and a test speed of 4.4 m/s, in the range from 10 to 30 J; b) a puncture energy at 23 °C, measured according to ISO 6603-2 using injection-moulded plaques of 60 x 60 x 3 mm and a test speed of 4.4 m/s, in the range from 15 to 50 J; c) a Charpy Notched impact strength at 23 °C, determined according to ISO 179 using 80* 10x4 mm³ test bars injection-moulded in line with ISO 19069- 2, in the range from 20 to 100 kJ/m²; and d) a flexural modulus, determined according to ISO 178 using 80x 10x4 mm³ test bars injection-moulded in line with ISO 19069-2, in the range from 1000 to 2000 MPa.

6. The polypropylene composition (PC) according to any one of the preceding claims, being obtainable by blending at least components a) to f) and optionally component g): a) from 20.0 to 50.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a heterophasic propylene-ethylene copolymer (HECO); b) from 1.0 to 30.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a mixed-plastic polypropylene blend (B) having a melt flow rate (MFR2), determined according to ISO 1133 at 230 °C and 2.16 kg, in the range from 8.0 to 25.0 g/ 10 min; c) from 14.0 to 24.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of an ethylene-octene elastomer (EC); d) from 5.0 to 17.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of an inorganic filler (F) other than mica; e) from 1.0 to 5.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a mica-containing pigment masterbatch (MPM) that comprises mica, at least one coloured pigment, and a carrier polymer; f) from 0.2 to 5.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of further additives (A); and g) from 0.0 to 10.0 wt.-%, relative to the total weight of the polypropylene composition (PC), of a propylene homopolymer (h-PP), wherein the total contents of components a) to f) and optionally component g) add up to at least 95 wt.-%, more preferably at least 98 wt.-%, most preferably 100 wt.- %, relative to the total weight of the polypropylene composition (PC).

7. The polypropylene composition (PC) according to claim 6, wherein the heterophasic propylene-ethylene copolymer (HECO) has one or more, preferably all, of the following properties: a) a melt flow rate (MFR2), determined according to ISO 1133 at 230 °C and 2.16 kg, in the range from 90 to 250 g/ 10 min; b) an ethylene content (C2(total)), determined by CRYSTEX QC analysis, in the range from 5.0 to 20.0 wt.-%; c) a soluble fraction (SF) content, determined by CRYSTEX QC analysis, in the range from 15.0 to 40.0 wt.-% and a crystalline fraction (CF) content, determined by CRYSTEX QC analysis, in the range from 60.0 to 85.0 wt.- 0 //o, . d) an ethylene content of the soluble fraction (C2(SF)), determined by CRYSTEX QC analysis, in the range from 25 to 40 wt.-%; e) an ethylene content of the crystalline fraction (C2(CF)), determined by CRYSTEX QC analysis, in the range from 0.0 to 4.0 wt.-%; f) an intrinsic viscosity of the soluble fraction (iV(SF)), determined by CRYSTEX QC analysis, in the range from 2.00 to 4.00 dL/g; g) an intrinsic viscosity of the crystalline fraction (iV(CF)), determined by CRYSTEX QC analysis, in the range from 0.50 to 1.70 dL/g; and h) an intrinsic viscosity ratio (iV(SF)ZiV(CF)), determined by CRYSTEX QC analysis, in the range from 2.80 to 5.00.

8. The polypropylene composition (PC) according to either claim 6 or claim 7, wherein the mica-containing pigment masterbatch (MPM) has one or more, preferably all, of the following features: a) a content of mica particles in the range from 10 to 50 wt.-% relative to the total weight of the mica-containing pigment masterbatch (MPM); b) a content of coloured pigment in the range from 0.50 to 20.0 wt.-% relative to the total mica-containing pigment masterbatch (MPM); and c) the coloured pigment is carbon black.

9. The polypropylene composition (PC) according to any one of claims 6 to 8, wherein the ethylene -octene elastomer (EC) has a melt flow rate (MFR2), determined according to ISO 1133 at 190 °C and 2.16 kg, in the range from 0.2 to 3.0 g/10 min and/or a density, determined according to ISO 1183-187, in the range from 850 to 870 kg/m³.

10. The polypropylene composition (PC) according to any one of claims 6 to 9, wherein the inorganic filler (F) is talc, preferably having a median particle size dso before compounding, as determined by the laser diffraction method according to ISO 13320-1, in the range from 1.0 to 20.0 pm and/or an aspect ratio before compounding, as determined by scanning electron microscopy, in the range from 2.0 to 9.0.

11. The polypropylene composition (PC) according to any one of claims 6 to 10, wherein the mixed-plastic polypropylene blend (B) has one or more, preferably all, of the following properties: a) an ethylene content (C2(total)), determined by CRYSTEX QC analysis, in the range from 2.5 to 10.0 wt.-%; b) a soluble fraction (SF) content in the range from 4.0 to 15.0 wt.-% and a crystalline fraction (CF) in the range from 85.0 to 96.0 wt.-%, both determined by CRYSTEX QC analysis; c) an ethylene content of the crystalline fraction (C2(CF)), determined by CRYSTEX QC analysis, in the range from 1.0 to 10.0 wt.-%; d) an ethylene content of the soluble fraction (C2(SF)), determined by CRYSTEX QC analysis, in the range from 20 to 50 wt.-%; e) an intrinsic viscosity of the crystalline fraction (iV(CF)), determined by CRYSTEX QC analysis, in the range from 1.00 to 2.20 dL/g; f) an intrinsic viscosity of the soluble fraction (iV(SF)), determined by CRYSTEX QC analysis, in the range from 1.00 to 2.20 dL/g; g) an inorganic residue content, as determined by calcination analysis according to DIN ISO 1172: 1996, of 0.05 to 3.0 wt.-%; h) a limonene content, determined by solid phase microextraction (HS-SPME- GC-MS), in the range from 0.10 to 25.0 ppm; and i) a density, determined according to ISO 1183-187, in the range from 0.890 to 0.950 kg/m³.

12. The polypropylene composition (PC) according to any one of claims 6 to 11, wherein the mixed-plastic polypropylene blend (B) has: a) a Charpy Notched impact strength at 23 °C, determined according to ISO 179 using 80* 10x4 mm³ test bars injection-moulded in line with ISO 19069- 2, in the range from 1.0 to 20.0 kJ/m²; and/or b) a flexural modulus, determined according to ISO 178 using 80x 10x4 mm³ test bars injection-moulded in line with ISO 19069-2, in the range from 1000 to 1600 MPa.

13. The polypropylene composition (PC) according to any one of claims 6 to 12, wherein the mixed-plastic polypropylene blend (B) originates from post-consumer waste.

14. An article, preferably an injection-moulded article, comprising the polypropylene composition according to any one of the preceding claims in an amount of at least 95 wt.-%, more preferably at least 98 wt.-%, most preferably at least 99 wt.-%.

15. A process for producing articles according to claim 14, comprising the steps of: a) blending a heterophasic propylene -ethylene copolymer (HECO) as defined in claim 6 or claim 7, a mixed-plastic polypropylene blend (B) as defined in claim 6, 11, 12 or 13, an ethylene-octene elastomer (EC) as defined in claim 6 or claim 9, an inorganic filler (F) as defined in claim 6 or claim 10, further additives (A) as defined in claim 6, and optionally a propylene homopolymer (h-PP) as defined in claim 6, thereby obtaining a polymer composition (PE); and b) injection moulding the polymer composition (PE) to form an injection- moulded article, wherein a mica-containing pigment masterbatch (MPM) as defined in claim 6 or claim 8 is added during the blending of step a) or during the injection moulding of step b).