EP4638578A1

EP4638578A1 - Colored thermoplastic composition

Info

Publication number: EP4638578A1
Application number: EP23821672.5A
Authority: EP
Inventors: Alberto FOGUET ROCA; Jürgen Rohrmann; Alexandre Martin; Sylvain BONNO
Original assignee: Basell Poliolefine Italia SRL
Current assignee: Basell Poliolefine Italia SRL
Priority date: 2022-12-19
Filing date: 2023-12-13
Publication date: 2025-10-29
Also published as: WO2024132732A1; CN120322497A; JP2025541180A; KR20250129692A

Abstract

A colored thermoplastic polymer composition (I) having a lightness value L* equal to or lower than 40 comprising: (A) up to and including 88.5 wt.% of a polyolefin; (B) up to and including 1.5 wt.% of a pigment; (C) up to and including 10.0 wt.% of a mica having a particle size equal to or lower than 3500 microns, a D50 ranging from 400 to 2500 microns and an aspect ratio equal to or greater than 30; and (D) optionally, but preferably, up to 7.0 wt.% of an additive, wherein the amounts of (A), (B), (C) and (D) are based on the total weight of (A), (B), (C) and optionally (D).

Description

TITLE

COLORED THERMOPLASTIC COMPOSITION

FIELD OF THE DISCLOSURE

[0001] The present disclosure relates to a molded article showing visually distinguishable inclusions embedded in a colored plastic matrix and to a thermoplastic polymer composition to obtain it.

BACKGROUND OF THE DISCLOSURE

[0002] Thermoplastic polyolefins are known to have a favorable balance of properties, like high impact resistance and stiffness, lightweight and recyclability, which render thermoplastic polyolefins suitable for use in producing molded items, in particular injection molded articles. Injection molded articles find use in many fields, like in the automotive field.

[0003] To satisfy the increase demand for decorative or aesthetically pleasing automotive parts, molded articles are painted, laminated with films or textile-like materials, or compounded with non-polymeric materials, like non-polymeric fibers.

[0004] For instance, US2002/065357A1 discloses a polypropylene molding composition containing up to 3wt.% of carbon fibers, which has a textile-like appearance.

[0005] The patent application US5723522A discloses a plastic material containing cellulose fibers, wherein the color of the plastic matrix in which the fibers are embedded is in contrast with the color of the fibers.

[0006] Embedding a non-polymeric material into a polymer matrix can cause the impairment of the mechanical properties of the thermoplastic polyolefin. Uncontrolled modification of the end properties should be carefully avoided especially in the automotive field, in which the technical requirements for plastic are extremely stringent.

[0007] In this frame, there is still the need to provide a thermoplastic composition having an appropriate balance of mechanical properties for use in extrusion or injection molding, which can be used for the production of a molded article having a decorative surface. SUMMARY OF THE DISCLOSURE

[0008] In a first aspect, the present disclosure provides a colored thermoplastic polymer composition (I) having a lightness value L*, measured in the CIELAB color space, equal to or lower than 40 comprising:

[0009] (A) up to and including 88.5% by weight of a polyolefin;

[0010] (B) up to and including 1.5% by weight of a pigment;

[0011] (C) up to and including 10.0% by weight of a mica having particle size equal to or lower than 3500 microns, a D50 ranging from 400 to 2500 microns and an aspect ratio equal to or greater than 30; and

[0012] (D) optionally, but preferably, up to and including 7.0% by weight of an additive,

[0013] wherein the amounts of (A), (B), (C) and (D) are based on the total weight of

(A)+(B)+(C)+(D).

[0014] The colored thermoplastic polymer composition (I) of the instant disclosure is endowed with a good balance of physical-mechanical properties which render the composition suitable for producing preferably, but not exclusively, extruded or injection molded articles having peculiar aesthetic features.

[0015] In a further aspect, the present disclosure refers to an article comprising the colored thermoplastic polymer composition (I). The article of the instant disclosure is characterized by visually distinguishable inclusions embedded into a colored thermoplastic polymer matrix.

[0016] Accordingly, in a still further aspect, the present disclosure provides the use of a mica having particle size equal to or lower than 3500 microns, a D50 ranging from 400 to 2500 microns and an aspect ratio equal to or greater than 30 to obtain visually distinguishable inclusions embedded in a colored thermoplastic polymer matrix, the matrix being characterized by a lightness L* value, measured in the CIELAB color space, equal to or lower than 40.

[0017] While multiple embodiments are disclosed, still other embodiments will become apparent to those skilled in the art from the following detailed description. As will be apparent, certain embodiments, as disclosed herein, are capable of modifications in various obvious aspects, all without departing from the spirit and scope of the claims as presented herein. Accordingly, the following detailed description is to be regarded as illustrative in nature and not restrictive. BRIEF DESCRIPTION OF THE DRAWING

[0018] The following figures illustrate preferred embodiments of the subject matter disclosed herein. The claimed subject matter may be understood by reference to the following description taken in conjunction with the accompanying figures, in which like reference numerals identify like elements, and in which:

[0019] FIG.l provides a picture of the injection molded test specimen of example El;

[0020] FIG.2 provides a picture of the injection molded test specimen of example E2;

[0021] FIG.3 provides a picture of the injection molded test specimen of comparative example

CE3;

[0022] FIG.4 provides a picture of the injection molded test specimen of comparative example

CE4.

DETAILED DESCRIPTION OF THE INVENTION

[0023] In the context of the present disclosure;

[0024] - the percentages are expressed by weight, unless otherwise specified;

[0025] - the total weight of a composition sums up to 100%, unless otherwise specified;

[0026] - the term “comprising” referred to a polymer, a plastic material, a polymer composition, mixture or blend, should be construed to mean “comprising or consisting essentially of’;

[0027] - the term “consisting essentially of’ means that, in addition to those components which are mandatory, other components may also be present in the material, provided that the essential characteristics of the material are not materially affected by their presence. Examples of components that, when present in customary amounts, do not materially affect the characteristics of a polymer or of a polyolefin composition, mixture or blend are catalyst residues, processing aids and melt stabilizers;

[0028] - the term “copolymer” is referred to a polymer deriving from the intentional polymerization of at least two different comonomers, i.e. the term “copolymer” includes terpolymers;

[0029] - the terms “pre-consumer waste” and “post-industrial waste” are synonyms and designate a material diverted from the waste stream originating from a manufacturing process. It might be material trimmings, faulty items, overstock raw materials, excess inventory, etc.; [0030] - the term “post-consumer waste” designate a material that is discarded after it has been used by a final consumer;

[0031] - the term “virgin” refers to a polymer obtained from monomers originating from petrochemical feedstock, like natural gas or crude oil, and which has never been used before in a manufacturing process.

[0032] In the following the individual components of the colored thermoplastic polymer composition (I) are defined in more detail. The individual components described below can be comprised in the colored thermoplastic polymer composition (I) in any combination.

[0033] The polyolefin (A) is preferably selected from the group consisting of polypropylene, polyethylene, polystyrene and combinations thereof. More preferably, the thermoplastic polyolefin is blend of polypropylene, polyethylene and polystyrene as described below.

[0034] The polypropylene is preferably selected from the group consisting of:

[0035] - propylene homopolymers;

[0036] - propylene copolymers with up to and including 10.0% by weight, preferably from

0.1% to 10.0% by weight, based on the weight of the copolymer, of a comonomer selected from ethylene, a CH2=CHR alpha-olefin, wherein R a linear or branched C2-C8 alkyl group, and combinations thereof;

[0037] - heterophasic propylene polymers comprising from 20% to 70% by weight of a fraction (a) comprising a propylene polymer selected from a propylene homopolymer, a propylene copolymer and combinations thereof, wherein the propylene copolymer contains up to and including 10.0% by weight, based on the weight of (a), of units deriving from a comonomer selected from ethylene, a CH2=CHR alpha-olefin and a combination thereof, wherein R is a linear or branched C2-C8 alkyl group; and from 30% to 80% by weight of a polymer fraction (b) comprising an ethylene copolymer with a comonomer selected from propylene, a CH2=CHR alpha-olefin, wherein R is a linear or branched C2-C8 alkyl group, and combinations thereof, wherein the ethylene copolymer contains from 20.0% to 80.0% by weight, based on the weight of fraction (b), of units derived from the comonomer, wherein the amounts of (a) and (b) are based on the weight of (a)+(b); and

[0038] - combinations thereof.

[0039] The polyethylene is preferably selected from the group consisting of high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), elastomeric copolymers of ethylene with from 15.0% to 80.0% by weight, based on the ethylene copolymer, of a comonomer selected from propylene, a CH2=CHR alpha-olefin, wherein R is a linear or branched C2-C8 alkyl group, and combinations thereof.

[0040] When the colored thermoplastic composition (I) comprises a blend of an heterophasic propylene polymer and a polyethylene, the polyethylene and the fraction (b) of the heterophasic propylene polymer are different.

[0041] The alpha-olefin comprised in the ethylene and propylene polymers is preferably independently selected from butene- 1, hexene- 1, octene- 1, 4-methyl-l -pentene and combinations thereof.

[0042] Propylene and ethylene polymers suitable for use as component (A) are known in the art. They can be obtained by polymerizing the relevant monomers in the presence of a Ziegler- Natta or metallocene catalyst system, using known polymerization processes and equipment. Propylene and ethylene polymers are also available on the market, like under the tradename of Hifax and Metocene marketed by LyondellBasell or Engage™ marketed by Dow.

[0043] The polystyrene is preferably a saturated or unsaturated styrene or alpha-methylstyrene block copolymer, preferably comprising up to and including 30% by weight of polymerized styrene, preferably from 5% to 30% by weight, more preferably from 10% to 20% by weight, based on the weight of the polystyrene.

[0044] More preferably, the polystyrene is a styrene block copolymer selected from the group consisting of: polystyrene-polybutadiene-polystyrene (SBS), polystyrene-poly(ethylene- butylene)-polystyrene (SEBS), polystyrene-poly(ethylene-propylene)-polystyrene (SEPS), polystyrene-polyisoprene-polystyrene (SIS), polystyrene-poly(isoprene-butadiene)-polystyrene (SIBS) and combinations thereof.

[0045] Styrene and alpha-methylstyrene block copolymers are preferably prepared by ionic polymerization of the relevant monomers and are commercially available, like under the tradename of Kraton™ marketed by Kraton Polymers.

[0046] In a particularly preferred embodiment, the polyolefin (A) comprises up to and including 50.0% by weight, preferably from 10.0% to 40.% by weight, more preferably from 15.0% to 35.0% by weight, based on the weight of the polyolefin (A), of a recycled polyolefin, preferably selected from recycled polypropylene, recycled polyethylene, recycles polystyrene and combinations thereof. [0047] The recycled polyolefin originates from a pre-consumer waste, a post-consumer waste or a combinations thereof, preferably from a post-consumer waste. In particular, the recycled polyolefin originates from the mechanical recycling of at least one of the above-mentioned waste streams. The mechanical recycling processes of post-consumer waste are known in the art and recycled polyolefins are also available on the market.

[0048] The pigment (B) comprised in the colored thermoplastic polymer composition (I) is a dark pigment which, when incorporated into the composition at the claimed concentration provides a colored thermoplastic polymer composition (I) having a lightness value L*, measured in the CIELAB color space, equal to or lower than 40.

[0049] The pigment (B) is organic, inorganic, organo-inorganic or a combination thereof; preferably it is selected from carbon black, oxides of a metal element selected from iron manganese, chromium and mixtures thereof; aniline black and combinations thereof. More preferably, the polymer (B) is carbon black.

[0050] Preferably, the colored thermoplastic polymer composition (I) comprises from 0.1% to 1.5% by weight, preferably from 0.1% to 1.5% by weight, more preferably from 0.3% to 1.0% by weight of the pigment (B), based on the sum of the weights of (A), (B), (C) and (D).

[0051] The pigment (B) is preferably blended with the other components of the colored thermoplastic polymer composition (I) as concentrated masterbatch, like dispersed in a polymer carrier.

[0052] The colored thermoplastic polymer composition (I) comprises up to and including 10.0% by weight, preferably from 1.0% to 10.0% by weight, more preferably from 2.0% to 8.0% by weight, still preferably from 3.0% to 6.0% by weight, of a mica (C) having particle size equal to or lower than 3500 microns, a D50 ranging from 400 to 2500 microns and an aspect ratio equal to or greater than 30.

[0053] More preferably, the mica (C) has at least one, preferably all, the following properties:

[0054] (i) particle size equal to or lower than 2000 microns, preferably equal to or lower than

1700 microns, more preferably equal to or lower than 1500 microns; a D50 ranging from 400 to 1500 microns, preferably from 600 to 1300 microns and a D10 equal to or greater than 300 microns, preferably equal to or greater than 400 microns, still preferably equal to or greater than 500 microns; and/or

[0055] (ii) an aspect ratio ranging from 30 to 90. [0056] In a preferred embodiment, the mica (C) is a coated mica, which comprises, still more preferably is coated with, a white inorganic pigment, preferably selected from the group consisting of titanium dioxide, zinc oxide, zinc sulfide and combinations thereof.

[0057] In one embodiment, the mica (C) has particle size ranging from 3500 to 1 microns, preferably from 2000 to 50 microns, more preferably from 1700 to 100 microns, still more preferably from 1500 to 200 microns.

[0058] The mica (C) is responsible for the formation of the white inclusions into the dark polymer matrix. If the particle size is greater than 3500 microns, the processing, like extrusion, of the colored thermoplastic polymer composition (I) of the present disclosure is difficult and clogging of the apparatus may occur. If the mica has mean particle size D50, and optionally also D10, outside the ranges described above, an insufficient amount of enclosures (bright/white dots) embedded in the colored thermoplastic matrix can be visually distinguished so that an aesthetic effect is perceived.

[0059] In preferred embodiments, the colored thermoplastic polymer composition (I) comprises from 0.5% to 7.0% by weight, preferably from 1.0% to 5.0% by weight, of an additive (D), wherein the amounts of (D) is based on the total weight of (A), (B), (C ), and (D).

[0060] The additive (D) preferably comprises at least one additive selected from a light stabilizer, like a UV stabilizer, a lubricant and combinations thereof, of the type generally used for plastics. The colored thermoplastic polymer composition (I) containing at least one additive (D) has improved scratch resistance with respect to the same composition lacking the additive.

[0061] Further compounds that are preferably comprised in the additive (D) are selected from the group consisting of nucleating agents, antistatic agents, anti-oxidants, slipping agents, lubricants, anti-acids, melt stabilizers, coupling agents and combinations thereof.

[0062] In embodiments, the colored thermoplastic polymer composition (I) further comprises up to and including 40.0% by weight, preferably from 1.0% to 40.0%, more preferably from 5.0% to 30.0% by weight, still preferably from 10.0% to 25.0% by weight, of an inorganic filler (E), wherein the amount (E) is based on the total amount of components (A), (B), (C ), (E) optionally (D).

[0063] The inorganic filler (E) is different from mica and is preferably selected from the group consisting of talc, glass fibers, glass beads, calcium carbonate, wollastonite and combinations thereof, talc being the most preferred. [0064] In a preferred embodiment, the colored thermoplastic polymer composition (I) comprises or consists of:

[0065] - up to 85.0% by weight, preferably from 60.0% to 83.0% by weight, more preferably from 70.0% to 80.0% by weight, of a thermoplastic polyolefin (A) comprising:

- from 45.0% to 65.0% by weight of a propylene polymer fraction (Al) comprising a virgin polypropylene and up to and including 50.0% by weight, preferably from 10.0% to 40.0% by weight, more preferably from 20.0% to 30.0% by weight, of recycled polypropylene (Rl), wherein the amount of the recycled polypropylene (Rl) is based on the weight of the propylene polymer fraction (Al);

- from 5.0% to 20.0% by weight of a virgin ethylene-alpha olefin elastomer (A2);

- from 1.0% to 10.0% of a virgin styrene-block copolymer (A3) comprising up to and including 30% by weight of polymerized styrene, preferably from 5% to 30% by weight, more preferably from 10% to 20% by weight, based on the weight of the polystyrene (A3), wherein the amounts of (Al), (A2) and (A3) are based on total weight of (Al), (A2) and (A3);

[0066] - from 0.1% to 1.5% by weight, preferably from 0.1% to 1.5% by weight, more preferably from 0.3% to 1.0% by weight of a pigment (B) as described above, preferably of carbon black;

[0067] - from 1.0% to 10.0% by weight, preferably from 2.0% to 8.0% by weight, more preferably from 3.0% to 6.0% by weight of a mica (C) as described above;

[0068] - from 0.5% to 7.0% by weight, preferably from 1.0% to 5.0% by weight, of the polymer additive (D) comprising an additive selected from a light stabilizer, a lubricant or combinations thereof; and

[0069] - from 1.0% to 40.0%, more preferably from 5.0% to 30.0% by weight, still preferably from 10.0% to 25.0% by weight, of an inorganic filler (E), preferably talc,

[0070] wherein the amounts of (A), (B), (C), (D) and (E) are based on the total weights of (A), (B), (C ), (D) and (E).

[0071] The virgin polypropylene comprised in the propylene polymer fraction (Al) is preferably selected from the group consisting of virgin propylene homopolymers, virgin heterophasic propylene copolymers and combinations thereof; more preferably the virgin polypropylene is a combination thereof. [0072] The virgin propylene homopolymer preferably has a melt flow rate greater than 800 g/10 min, preferably ranging from 1,000 to 2,000 g/lOmin, measured according to the method ISO 1133-1 :2011 (230°C/2.16kg).

[0073] The virgin propylene homopolymer comprised in the propylene polymer fraction (Al) is obtained by polymerizing propylene in the presence of any catalyst system suitable to obtain highly stereospecific propylene homopolymers, like a Ziegler Natta catalyst system or a metallocene catalyst, of the type known in the art.

[0074] The virgin heterophasic propylene copolymer comprised in the propylene polymer fraction (Al) preferably comprises:

[0075] - from 30% to 70% by weight, preferably from 40% to 70% by weight, of a fraction

(a) comprising a propylene polymer selected from a propylene homopolymer, a propylene copolymer and combinations thereof, wherein the propylene copolymer contains up to and including 10.0% by weight, based on the weight of the fraction (a), of units deriving from a comonomer selected from ethylene, a CH2=CHR alpha-olefin and a combination thereof, wherein R is a linear or branched C2-C8 alkyl group, and wherein the fraction (a) has solubility in xylene at 25°C equal to or lower than 10.0% by weight, preferably equal to or lower than 8.0% by weight, based on the weight of the fraction (a); and

[0076] - from 30% to 70% by weight, preferably from 30% to 60% by weight, of a polymer fraction (b) comprising a copolymer of ethylene with a comonomer selected from propylene, a CH2=CHR alpha-olefin, wherein R is a linear or branched C2-C8 alkyl group, and combinations thereof, wherein the ethylene copolymer contains from 20.0% to 50.0% by weight, preferably from 25% to 45% by weight, based on the weight of the fraction (b), of units deriving from the comonomer, and wherein the amounts of (a) and (b) are referred to the sum of the weights of (a)+(b).

[0077] The alpha-olefin comprised in fraction (a) and (b) is preferably independently selected from butene- 1, hexene- 1, octene- 1, 4-methyl-l -pentene and combinations thereof.

[0078] The virgin heterophasic propylene polymer comprised in the propylene polymer fraction (Al) preferably has at least one, preferably all the following properties:

[0079] - the fraction (a) consists essentially of a propylene homopolymer; and/or

[0080] - the fraction (a) has solubility in xylene at 25 °C determined according to the method described in the experimental section equal to or lower than 5.0% by weight; and/or [0081] - the comonomer comprised in the fraction (b) is propylene; and/or

[0082] - a melt flow rate ranges from 0.5 to 40.0 g/10 min, more preferably from 0.7 to 30.0 g/10 min, measured according to the method ISO 1133-1 :2011 (230°C/2.16kg); and/or

[0083] - comprises a fraction soluble in xylene at 25°C ranging from 20% to 50% by weight, based on the weight of the heterophasic propylene polymer, wherein the xylene soluble fraction is measured as described in the experimental section; and/or

[0084] - a flexural modulus ranging from 500 MPa to 900 MPa, measured according to the method ISO 178:2010 on injection molded test specimens.

[0085] The virgin heterophasic propylene polymer comprised in the propylene polymer fraction (Al) is preferably obtained by polymerizing the relevant monomers in the liquid or gasphase in at least two polymerization stages, wherein the second and each subsequent polymerization stage is carried out in the presence of the polymer produced and the catalyst system used in the immediately preceding polymerization stage.

[0086] The polymerization of the relevant monomers is preferably carried out in the presence of a highly stereospecific Ziegler-Natta catalyst systems comprising:

[0087] (1) a solid catalyst component comprising a magnesium halide support on which a Ti compound having at least a Ti-halogen bond is present, and a stereoregulating internal donor;

[0088] (2) optionally, but preferably, an Al-containing cocatalyst; and

[0089] (3) optionally, but preferably, a further electron-donor compound (external donor).

[0090] The solid catalyst component (1) preferably comprises TiCL in an amount securing the presence of from 0.5 to 10% by weight of Ti with respect to the total weight of the solid catalyst component (1).

[0091] The solid catalyst component (1) comprises at least one stereoregulating internal electron donor compound selected from mono or bidentate organic Lewis bases, preferably selected from esters, ketones, amines, amides, carbamates, carbonates, ethers, nitriles, alkoxysilanes and combinations thereof.

[0092] Suitable donors are the esters of phthalic acids such as those described in EP45977A2 and EP395083 A2, in particular di-isobutyl phthalate, di-n- butyl phthalate, di-n-octyl phthalate, diphenyl phthalate, benzylbutyl phthalate and combinations thereof. [0093] Esters of aliphatic acids can also be selected from esters of malonic acids such as those described in WO98/056830, WO98/056833, WO98/056834, esters of glutaric acids such as those disclosed in WOOO/55215, and esters of succinic acids such as those disclosed WOOO/63261.

[0094] Particular type of diesters are those deriving from esterification of aliphatic or aromatic diols such as those described in W02010/078494 and USP 7,388,061.

[0095] In a preferred embodiment, the internal donor is selected from 1,3-diethers such as those described in EP361493, EP728769 and WO02/100904.

[0096] Specific mixtures of internal donors, in particular of aliphatic or aromatic mono or dicarboxylic acid esters and 1,3-diethers as disclosed in W007/57160 and WO2011/061134 can be used as internal donor.

[0097] Preferred magnesium halide support is magnesium dihalide.

[0098] The amount of internal donor that remains fixed on the solid catalyst component (1) is 5 to 20% by moles, with respect to the magnesium dihalide.

[0099] The preparation of catalyst components according to a general method is described for example in European Patent Applications US4,399,054, US4,469,648, W098/44009A1 and EP395083A2.

[0100] The catalyst system preferably comprises an Al-containing cocatalyst (2) selected from Al-trialkyls, preferably selected from the group consisting of Al-triethyl, Al-triisobutyl and Al-tri- n-butyl. The Al/Ti weight ratio in the catalyst system is from 1 to 1000, preferably from 20 to 800. [0101] In preferred embodiments, the catalyst system comprises a further electron donor compound (3) (external electron donor) selected among silicon compounds, ethers, esters, amines, heterocyclic compounds, particularly 2,2,6,6-tetramethylpiperidine, and ketones.

[0102] Preferred silicon compounds are selected among methylcyclohexyldimethoxysilane (C-donor), dicyclopentyldimethoxysilane (D-donor) and mixtures thereof.

[0103] The polymerization temperature is preferably comprised in the range from 20°C to 100°C and the polymerization pressure is preferably from 3.3 to 4.3 MPa for a process in liquid phase and from 0.5 to 3.0 MPa for a process in the gas phase.

[0104] The molecular weight of the polymers is regulated by feeding a molecular weight regulator, like hydrogen, into a polymerization reactor.

[0105] The amounts of components (a) and (b) correspond to the split between the reactors. [0106] The recycled propylene polymer (Rl) is preferably a mechanically recycled polypropylene deriving from a pre-consumer waste stream, or a post-consumer waste stream, or a combinations thereof, especially from a post-consumer waste stream, the recycled propylene polymer (Rl) having at least one, preferably all, the following properties:

[0107] - melt flow rate ranging from 5.0 to 20.0 g/lOmin, preferably from 8.0 to 17.0 g/lOmin, measured according to the method ISO 1133-1 :2011 (230°C/2.16kg); and/or

[0108] - a flexural modulus ranging from 700 MPa to 1500 MPa, preferably from 800 MPa to

1200 MPa, measured according to the method ISO 178:2010 on injection molded test specimens.

[0109] The virgin ethylene-alpha olefin elastomer (A2) preferably comprises 15.0% to 50.0% by weight, based on the ethylene-alpha olefin elastomer, of a comonomer selected from propylene, a CH2=CHR alpha-olefin, wherein R is a linear or branched C2-C8 alkyl group, and combinations thereof. The alpha-olefin is preferably selected from butene- 1, hexene- 1, octene- 1, 4-methyl-l- pentene and combinations thereof.

[0110] The virgin ethylene-alpha olefin elastomer (A2) is different from the fraction (b).

[0111] The ethylene-alpha olefin elastomer (A2) preferably has at least one, more preferably all the following properties:

[0112] - a density ranging from 0.862 to 0.870 g/cm³, measured according to the method

ASTM D792; and/or

[0113] - a melt index ranging from 1.0 to 10.0 g/lOmin, preferably from 3.0 to 8.0 g/lOmin, measured according to the method ISO 1133-1 :2011 (190°C/2.16kg); and/or

[0114] - a tear strength ranging from 15.0 to 30.0 kN/m, measured according to the method

ASTM D624; and or

[0115] - a tensile modulus (100% secant) ranging from 0.5 MPa to 3.0 MPa, measured according to the method ASTM D638 on compression molded test specimens.

[0116] Ethylene copolymers (A2) are commercially available for example under the tradename of Engage, marketed by Dow® and are generally prepared using known polymerization processes, like solution polymerization carried out in the presence of a metallocene-based catalyst system.

[0117] The styrene block copolymer (A3) preferably has at least one, preferably all, the following properties: [0118] - melt index ranging from 5.0 to 50.0 g/10min., preferably from 10.0 to 40.0 g/10min., measured according to the method ASTM D1238 (230°C, 5.0 Kg); and/or

[0119] - Shore A value equal to or lower than 60, preferably ranging from 30 to 65, measured according to the method ASTM 2240 (10 sec.).

[0120] The colored thermoplastic polymer composition (I) of the present disclosure is prepared by blending the components in an extruder, preferably in a twin-screw extruder, either co-rotating or counter-rotating, operated under conventional conditions, like a temperature above the melting temperature of the thermoplastic polyolefin (A), preferably at a die temperature equal to or greater than 220°C, preferably ranging from 210°to 270°C.

[0121] In a preferred embodiment, the process to prepare the colored thermoplastic polymer composition (I) comprises feeding the components to a twin-screw extruder, wherein the mica (C) is fed via a side feeder.

[0122] The colored thermoplastic polymer composition (I) has at least one, preferably all, the following properties:

[0123] - a lightness value L*, measured in the CIELAB color space, equal to or lower than

30; and/or

[0124] - a lightness value L*, measured in the CIELAB color space, equal to or greater than

0.5; and/or

[0125] - melt flow rate equal to or greater than 10.0 g/lOmin, preferably ranging from 15.0 to

50.0 g/10 min, according to the method ISO 1133-1:2011 (230°C/2.16 kg); and/or

[0126] - flexural modulus equal to or greater than 1200 MPa, preferably ranging from 1350

MPa to 1800 MPa, measured according to the method ISO 178:2010 on injection molded test specimens; and/or

[0127] - impact resistance, as measured by the Charpy notched impact according to the method AcN ISO 179/leA, equal to or greater than 30 mJ/mm², preferably ranging from 35 to 50 mJ/mm², at 23°C and equal to or greater than 3.0 mJ/mm², preferably ranging from 3.5 to 7.0 mJ/mm², at -20°C.

[0128] The lightness L* of the colored thermoplastic composition (I) is determined on a portion of the composition wherein no inclusion is embedded. [0129] The colored thermoplastic polymer composition (I) of the present disclosure are suitable to produce articles having a good balance of physical-mechanical properties and a pleasant aesthetic appearance.

[0130] Accordingly, in a further aspect, the present disclosure refers to an article comprising the colored thermoplastic polymer composition (I) described above, characterized in that the article comprises visually distinguishable inclusions embedded in a colored thermoplastic polymer matrix. Preferably, the article is an injection molded article, like an interior or exterior part of a vehicle.

[0131] In a preferred embodiment, the article comprises at least 13,000 visually distinguishable inclusions per square meter (acceptable results), more preferably from 14,000 to 20,000 visibly distinguishable inclusions per square meter.

[0132] Preferably, the visually distinguishable inclusions have a nominal diameter equal to or greater than 150 microns, preferably ranging from 150 to 1,500 microns, wherein the nominal diameter corresponds to the diameter of a circle encompassing the visually distinguishable inclusion.

[0133] The visually distinguishable inclusions appears as white dots embedded in a dark plastic matrix.

[0134] In a further aspect, the present disclosure refers to the use of a mica having particle size equal to or lower than 3,500 microns, a D50 ranging from 400 to 2500 microns and an aspect ratio equal to or greater than 30 to obtain visually distinguishable inclusions embedded in a colored thermoplastic polymer matrix having a lightness L* value, measured in the CIELAB color space, equal to or lower than 40.

[0135] The mica (c) is preferably endowed with at least one, preferably all, the properties disclosed above.

[0136] The thermoplastic polymer is preferably as described above.

[0137] The features describing the subject matter of the present disclosure are not inextricably linked to each other. Hence, preferred ranges of one feature may be combined with more or less preferred ranges of a different feature, independently from their level of preference.

[0138] EXAMPLES

[0139] The following examples are illustrative only, and are not intended to limit the scope of the disclosure in any manner whatsoever. [0140] CHARACTERIZATION METHODS: the following methods are used to determine the properties indicated in the description, claims and examples.

[0141] Melt Flow Rate: Determined according to the method ISO 1133-1 :2011.

[0142] Solubility in xylene at 25°C for propylene polymers: 2.5 g of polymer sample and

250 ml of xylene are introduced in a glass flask equipped with a refrigerator and a magnetic stirrer. The temperature is raised in 30 minutes up to 135°C. The obtained clear solution is kept under reflux and stirring for further 30 minutes. The solution is cooled in two stages. In the first stage, the temperature is lowered to 100°C in air for 10 to 15 minute under stirring. In the second stage, the flask is transferred to a thermostatically controlled water bath at 25°C for 30 minutes. The temperature is lowered to 25°C without stirring during the first 20 minutes and maintained at 25°C with stirring for the last 10 minutes. The formed solid is filtered on quick filtering paper (eg. Whatman filtering paper grade 4 or 541). 100 ml of the filtered solution (SI) is poured in a previously weighed aluminum container, which is heated to 140°C on a heating plate under nitrogen flow, to remove the solvent by evaporation. The container is then kept on an oven at 80°C under vacuum until constant weight is reached. The amount of polymer soluble in xylene at 25°C is then calculated. XS(I) and XSA values are experimentally determined. The fraction of component (B) soluble in xylene at 25°C (XSB) can be calculated from the formula:

XS = W(A)X(XSA) + W(B)X(XSB) wherein W(A) and W(B) are the relative amounts of components (A) and (B), respectively, and W(A)+ W(B)=1.

[0143] Comonomer content: determined by IR using Fourier Transform Infrared Spectrometer (FTIR). The spectrum of a pressed film of the polymer is recorded in absorbance vs. wavenumbers (cm-1). The following measurements are used to calculate the ethylene content:

- Area (At) of the combination absorption bands between 4482 and 3950 cm-1 which is used for spectrometric normalization of film thickness;

- a linear baseline is subtracted in the range 790 - 660 cm-1 and the remaining constant offset is eliminated;

The method is calibrated by using polymer standards based on 13C NMR analyses.

Sample preparation: Using a hydraulic press, a thick sheet is obtained by pressing about 1g of sample between two aluminum foils. Pressing temperature is 180±10°C (356°F) and about 10 kg/cm2 pressure for about one minute (minimum two pressing operations for each specimen). A small portion is cut from this sheet to mold a film. Recommended film thickness ranges between 0.02-0.05 cm.

[0144] Flexural Modulus: determined according to the method ISO 178:2010 on injection molded test specimens (80 x 10 x 4 mm) obtained according to the method ISO 1873-2:2007.

[0145] Impact resistance: Charpy notched impact AcN determined according to the method ISO 179/leA at 23 °C and at -20°C.

[0146] Shrinkage: measured on injection molded plaques. 10 test specimen are obtained by injection molding of the thermoplastic composition in a 194,96 x 99,66 x 2,48 mm mold using a Krauss Maffei KM 160 CX injection molding machine (mold temperature 35°C, injection speed 33 mm/s, cooling time 30 min.). The specimens are conditioned for 48h at a temperature of 23±2°C before testing. The dimensions of the specimens are measured with a micrometer and compared to the dimensions of the reference metallic plaque having the same dimensions of the mould. The shrinkage is calculated as mean value over 10 measures using the following formula:

100 x DR - DS) Ci = -

DR

[0147] wherein

Ci is the shrinkage in one selected direction (longitudinal or transverse);

DR is the dimension of the reference metallic plaque in the selected direction; and

DS is the dimension of the sample in the selected direction.

[0148] Lightness: measured in the CIELAB color space with a d/8° geometry sphere spectrophotometer Datacolor 850; illuminating source: pulsed xenon filtered to approximate D65. [0149] Particle size, D50 and D10: measured by sieve analysis. By definition, D50 > D10.

[0150] Mica aspect ratio, number of inclusions per m² and dimension of the inclusions: visually determined using a digital microscope on an injection molded article.

[0151] RAW MATERIALS:

[0152] PPI: a propylene polymer composition consisting essentially of 42% by weight of a fraction (a) comprising a propylene homopolymer and 58% by weight of a fraction (b) comprising propylene-ethylene copolymer containing 42% by weight of units derived from ethylene, the propylene polymer composition having melt flow rate (230°C, 2.16 Kg) of 20.0 g/lOmin and solubility in xylene at 25°C of 35.0% by weight, having flexural modulus greater than 600 MPa. The propylene polymer composition PPI is a reactor blend of fraction (a) and fraction (b) obtained by a sequential polymerization in two stages of the relevant monomers.

[0153] PP2: a propylene polymer composition comprising 67% by weight of a fraction (a) comprising a propylene homopolymer, the fraction (a) having solubility in xylene lower than 2.5% by weight and 33% by weight of a fraction (b) comprising a propylene ethylene copolymer containing 33% by weight of units deriving from ethylene, the propylene polymer composition comprising a fraction soluble in xylene of 29.0% by weight and having melt flow rate (230°C, 2.16Kg) of 0.9 g/lOmin and a flexural modulus of 800 MPa. The propylene polymer composition PP2 was obtained as described in W02004/087805, example 4.

[0154] PP3: an extremely high melt flow rate propylene homopolymer having melt flow rate (230°C, 2.16 Kg) of 1800 g/lOmin obtained by a metallocene catalyst system.

[0155] rPP: mechanically recycled polypropylene having melt flow rate (230°C, 2.16 Kg) of 12.0 g/lOmin, density of 0.90 g/cm3 (ISO1183) and flexural modulus of 1100 MPa.

[0156] Engage™ 11547: an ethylene-octene elastomer marketed by Dow, having melt index (ASTM D1238, 190°C/2.16Kg) of 5.0 g/lOmin, tensile modulus 100% secant (ASTM D638 on compression molded samples) 1.50 MPa and tear strength (ASTM D624) of 22.0 kN/m.

[0157] Kraton™ G1657: a linear triblock copolymer based on styrene and ethylene/butylene marketed by Kraton Corp., with a polystyrene content of 13 wt.%, having melt index (230°C, 5.0 Kg) of 22.0 G710 min and a Shore A value (ASTM D2240) of 47.

[0158] Luzenac HAR® talc T84: a talc marketed by Imerys.

[0159] Micacolor 600SF : mica marketed by SOPAP (Societe de Production et d’ Adaptation des Polymeres), France. Micacolor 600SF has particle size lower than 1300 microns, D50 of ca.870 microns and D10 of ca. 630 microns.

[0160] Micavi 700 : supplied by Cavisa, the mica has particle size lower than 900 microns, D50 of ca.450 microns and D10 of ca. 320 microns.

[0161] Mica-MU™ 800: mica marketed by Imerys having particle size of less than 900 microns, a D50 lower than 300 microns and a D10 lower than 100 microns.

[0162] Chimassorb® 944: light stabilizer marketed by BASF (CAS No. 71878-19-8).

[0163] Tinuvin® 770: bis(2,2,6,6,-tetramethyl-4-piperidyl)sebacate, a light stabilizer marketed by BASF. [0164] Pigment concentrate: masterbatch containing 70 wt.% of carbon black and 50 wt.% of polyolefin carrier.

[0165] Examples El and comparative examples CE2-CE4

[0166] Colored thermoplastic polymer compositions were prepared by blending the components indicated in table 1 in a ZSK-70 extruder, operated at a melting temperature ranging from 185°C to 240°C at 200-300 rpm.

[0167] The mica and talc were fed to the extruder via side feeder.

[0168] The composition were injection molded into test specimens 80 x 10 x 4 mm obtained according to the method ISO 1873-2:2007, tested and visually inspected. Results are illustrated in table 1.

Table 1

Claims

What is claimed is:

1. A colored thermoplastic polymer composition (I) having a lightness value L*, measured in the CIELAB color space, equal to or lower than 40 comprising:

(A) up to and including 88.5% by weight of a polyolefin;

(B) up to and including 1.5% by weight of a pigment;

(C) up to and including 10.0% by weight of a mica having a particle size equal to or lower than 3500 microns, a D50 ranging from 400 to 2500 microns and an aspect ratio equal to or greater than 30; and

(D) optionally, but preferably, up to and including 7.0% by weight of an additive, wherein the amounts of (A), (B), (C) and (D) are based on the total weight of (A), (B), (C) and optionally (D).

2. The colored thermoplastic polymer composition (I) of claim 1 , wherein the polyolefin (A) is selected from the group consisting of polypropylene, polyethylene, polystyrene and combinations thereof.

3. The colored thermoplastic polymer composition (I) according to claim 1 or 2, wherein the polyolefin (A) comprises up to and including 50.0% by weight, preferably from 10.0% to 40.% by weight, more preferably from 15.0% to 35.0% by weight, based on the weight of the polyolefin (A), of a recycled polyolefin, preferably selected from recycled polypropylene, recycled polyethylene, recycled polystyrene and combinations thereof.

4. The colored thermoplastic polymer composition (I) according to any one of the previous claims, wherein the pigment (B) is selected from carbon black, oxides of a metal element selected from iron, manganese, chromium and mixtures thereof; aniline black and combinations thereof, preferably carbon black.

5. The colored thermoplastic polymer composition (I) according to any one of the previous claims comprising from 0.1% to 1.5% by weight, preferably from 0.1% to 1.5% by weight, more preferably from 0.3% to 1.0% by weight of the pigment (B), wherein the amount of (B) is based on the total weight of (A), (B), (C) and optionally (D).

6. The colored thermoplastic polymer composition (I) according to any one of the previous claims, wherein the mica is a coated mica.

7. The colored thermoplastic polymer composition (I) according to any one of the previous claims, wherein the mica (C) has at least one, preferably all, the following properties:

(i) a particle size equal to or lower than 2000 microns, preferably equal to or lower than 1700 microns, more preferably equal to or lower than 1500 microns; a D50 ranging from 400 to 1500 microns, preferably from 600 to 1300 microns and a D10 equal to or greater than 300 microns, preferably equal to or greater than 400, more preferably equal to or greater than 500 microns; and/or

(ii) an aspect ratio ranging from 30 to 90.

8. The colored thermoplastic polymer composition (I) according to any one of the previous claims comprising from 1.0% to 10.0% by weight, preferably from 2.0% to 8.0% by weight, more preferably from 3.0% to 6.0% by weight of mica (C), wherein the amount of (C) is based on the sum of the weights of (A), (B), (C) and optionally (D).

9. The colored thermoplastic polymer composition (I) according to any one of previous claims comprising from 0.5% to 7.0% by weight, preferably from 1.0% to 5.0% by weight, of the polymer additive (D), wherein the amount of (D) is based on the total weight of (A), (B), (C) and (D).

10. The colored thermoplastic polymer composition (I) according to any one of the previous claims, wherein the polymer additive (D) comprises an additive selected from a light stabilizer, a lubricant and a combination thereof.

11. The colored thermoplastic polymer composition (I) according to any one of the previous claims, further comprising up to and including 40.0% by weight, preferably from 1.0% to

40.0%, more preferably from 5.0% to 30.0% by weight, still preferably from 10.0% to 25.0% by weight, of an inorganic filler (E), wherein the amount of (E) is based on the sum of the weights of components (A), (B), (C ), (E) and optionally (D).

12. The colored thermoplastic polymer composition (I) according to claim 11, wherein the inorganic filler (E) is selected from the group consisting of talc, glass fibers, glass beads, calcium carbonate, wollastonite and combinations thereof.

13. The colored thermoplastic polymer composition (I) according to any one of the previous claims comprising:

- up to and including 85.0% by weight, preferably from 60.0% to 83.0% by weight, more preferably from 70.0% to 80.0% by weight, of a polyolefin (A) comprising:

- from 45.0% to 65.0% by weight of a propylene polymer fraction (Al) comprising a virgin polypropylene and up to and including 50.0% by weight, preferably from 10.0% to 40.0% by weight, more preferably from 20.0% to 30.0% by weight of a recycled polypropylene (Rl), wherein the amount of the recycled polypropylene (Rl) is based on the weight of the propylene polymer fraction (Al);

- from 5.0% to 20.0% by weight of a virgin elastomeric copolymer (A2) of ethylene with comonomer selected from propylene, a CH2=CHR alpha-olefin, , wherein R is a linear or branched C2-C8 alkyl group, and combinations thereof;

- from 1.0% to 10.0% of a virgin styrene-block copolymer (A3) comprising up to and including 30% by weight, preferably from 5% to 30% by weight, more preferably from 10% to 20% by weight, of polymerized styrene, based on the weight of the virgin styrene-block copolymer (A3), wherein the amounts of (Al), (A2) and (A3) are based on the sum of the weights of (Al), (A2) and (A3);

- from 0.1% to 1.5% by weight, preferably from 0.1% to 1.5% by weight, more preferably from 0.3% to 1.0% by weight of a pigment (B), preferably of carbon black;

- from 1.0% to 10.0% by weight, preferably from 2.0% to 8.0% by weight, more preferably from 3.0% to 6.0% by weight of a mica (C); - from 0.5% to 7.0% by weight, preferably from 1.0% to 5.0% by weight, of a polymer additive (D) comprising an additive selected from a light stabilizer, a lubricant and combinations thereof; and

- from 1.0% to 40.0%, more preferably from 5.0% to 30.0% by weight, still preferably from 10.0% to 25.0% by weight, of an inorganic filler (E), preferably of talc, wherein the amounts of (A), (B), (C), (D) and (E) are based on the total weight of (A), (B), (C ), (D) and (E).

14. An article, preferably an injection molded article, comprising the colored thermoplastic polymer composition (I) according to any one of claims 1-13, characterized in that the article comprises visually distinguishable inclusions embedded in a colored thermoplastic polymer matrix.

15. Use of a mica having particle size equal to or lower than 3500 microns, a D50 ranging from 400 to 2500 microns and an aspect ratio equal to or greater than 30 to obtain visually distinguishable inclusions embedded in a colored thermoplastic polymer matrix having a lightness L* value, measured in the CIELAB color space, equal to or lower than 40.