Colored thermoplastic composition

Abstract

A colored thermoplastic polymer composition (I) having a brightness value L * equal to or less than 40, the colored thermoplastic polymer composition comprising: (A) up to and comprising 88.5 wt% 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 mica having a particle size equal to or less than 3500 microns, a D50 in the range of 400 microns 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 amount of (A), the amount of (B), the amount of (C) and the amount of (D) are based on the total weight of (A), (B), (C) and optionally (D).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a molded article showing visually distinguishable inclusions embedded in a colored plastic matrix and a thermoplastic polymer composition for obtaining such molded article. BACKGROUND ART

[0002] It is known that thermoplastic polyolefins have a good balance of properties such as high impact resistance and rigidity, light weight and recyclability, which makes thermoplastic polyolefins suitable for the production of molded articles, in particular injection molded articles. Injection molded articles are used in many fields, such as the automotive field.

[0003] In order to meet the growing demand for decorative or aesthetic automotive parts, molded articles are painted, laminated with films or materials similar to textiles, or compounded with non-polymeric materials (such as non-polymeric fibers).

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

[0005] Patent application US5723522A discloses a plastic material containing cellulose fibers, wherein the color of the plastic matrix in which these fibers are embedded contrasts with the color of these fibers.

[0006] Embedding non-polymeric materials in a polymer matrix may result in impairment of the mechanical properties of thermoplastic polyolefins. Uncontrolled modification of the final properties should be carefully avoided, especially in the automotive field where the technical requirements for plastics are extremely strict.

[0007] Against this background, there is still a need to provide a thermoplastic composition that can be used to produce molded articles with a decorative surface and that has an appropriate balance of mechanical properties for extrusion or injection molding. SUMMARY OF THE INVENTION

[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 less than 40, the colored thermoplastic polymer composition 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 mica, the mica having a particle size equal to or less than 3500 microns, a D50 in the range of 400 microns 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 present disclosure has a good balance of physical and mechanical properties, which makes the composition suitable for the production of extruded or injection molded articles preferably (but not limited to) having unique aesthetic features.

[0015] In another aspect, the present disclosure relates to an article comprising the colored thermoplastic polymer composition (I). The articles of the present disclosure are characterized by visually distinguishable inclusions embedded in a colored thermoplastic polymer matrix.

[0016] Thus, in yet another aspect, the present disclosure provides a use of mica for obtaining visually distinguishable inclusions embedded in a colored thermoplastic polymer matrix, the mica having a particle size equal to or less than 3500 microns, a D50 in the range of 400 microns to 2500 microns, and an aspect ratio equal to or greater than 30, the matrix being characterized by a lightness L* value equal to or less than 40 measured in the CIELAB color space.

[0017] Although multiple embodiments are disclosed, 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 can be modified in various obvious respects without departing from the spirit and scope of the claims presented herein. Accordingly, the following detailed description should be regarded as illustrative in nature and not restrictive. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0019] Figure 1 A picture of an injection molded test specimen of Example E1 is provided;

[0020] Figure 2 A picture of an injection molded test specimen of Example E2 is provided;

[0021] Figure 3 Provides a picture of the injection molded test specimen of Comparative Example CE3;

[0022] Figure 4 A picture of the injection molded test specimen of Comparative Example CE4 is provided. DETAILED DESCRIPTION

[0023] In the context of this disclosure;

[0024] - Unless otherwise stated, percentages are expressed by weight;

[0025] - unless otherwise stated, the total weight of the compositions adds up to 100%;

[0026] - the term "comprising" in relation to a polymer, plastic material, polymer composition, mixture or blend shall be interpreted as meaning "comprising or consisting essentially of";

[0027] - The term "consisting essentially of" means that in addition to the mandatory ones, other components may also be present in the material, provided that the basic characteristics of the material are not substantially affected by their presence. Examples of components that do not substantially affect the characteristics of the polymer or polyolefin composition, mixture or blend when present in conventional amounts are catalyst residues, processing aids and melt stabilizers;

[0028] - the term "copolymer" refers to a polymer derived 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 synonymous and refer to material diverted from the waste stream generated by the manufacturing process. It may be material offcuts, defective items, overstocked raw materials, excess inventory, etc.;

[0030] - The term “post-consumer waste” refers to materials discarded after use by the final consumer;

[0031] - The term "virgin" refers to polymers that are obtained from monomers derived from petrochemical feedstocks, such as natural gas or crude oil, and that have 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 may be contained 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 a blend of polypropylene, polyethylene and polystyrene as described below.

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

[0035] - Polypropylene homopolymer;

[0036] - Polypropylene copolymer having up to and including 10.0 wt%, preferably 0.1 wt% to 10.0 wt% of comonomer(s), based on the weight of the copolymer, the comonomer(s) being selected from ethylene, CH2=CHR α-olefins and combinations thereof, where R is a straight-chain or branched C2-C8 alkyl group;

[0037] - Heterophasic polypropylene polymer comprising: 20 wt% to 70 wt% of fraction (a), which contains a polypropylene polymer selected from polypropylene homopolymer, polypropylene copolymer and combinations thereof, where the polypropylene copolymer contains up to and including 10.0 wt% of units derived from the comonomer(s), based on the weight of (a), the comonomer(s) being selected from ethylene, CH2=CHR α-olefins and combinations thereof, where R is a straight-chain or branched C2-C8 alkyl group; and 30 wt% to 80 wt% of polymer fraction (b), which contains an ethylene copolymer having a comonomer selected from propylene, CH2=CHR α-olefins and combinations thereof, where R is a straight-chain or branched C2-C8 alkyl group, where the ethylene copolymer contains 20.0 wt% to 80.0 wt% of units derived from the comonomer(s), based on the weight of fraction (b),

[0038] where the amounts of (a) and (b) are based on the weight of (a)+(b); and

[0039] - Combinations thereof.

[0040] The polyethylene is preferably selected from the group consisting of high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and an elastomeric copolymer of ethylene with 15.0 wt% to 80.0 wt% of comonomer(s) based on the ethylene copolymer, the comonomer(s) being selected from propylene, CH2=CHR α-olefins and combinations thereof, where R is a straight-chain or branched C2-C8 alkyl group.

[0041] When the colored thermoplastic composition (I) comprises a blend of a heterophasic polypropylene polymer and polyethylene, the polyethylene is different from fraction (b) of the heterophasic polypropylene polymer.

[0042] The α-olefins contained in the ethylene and propylene polymers are preferably independently selected from butene-1, hexene-1, octene-1, 4-methyl-1-pentene and combinations thereof.

[0043] Propylene and ethylene polymers suitable for use as component (A) are known in the art. They can be obtained by polymerizing the relevant monomers using known polymerization methods and equipment in the presence of a Ziegler-Natta or metallocene catalyst system. Propylene and ethylene polymers are also available on the market, such as under the trade names Hifax and Metocene sold by LyondellBasell or Engage sold by Dow TM obtained.

[0044] The polystyrene is preferably a saturated or unsaturated styrene or α-methylstyrene block copolymer, preferably containing up to and including 30% by weight of polymerized styrene, preferably 5% to 30% by weight, more preferably 10% to 20% by weight, these weight percentages being based on the weight of the polystyrene.

[0045] More preferably, the polystyrene is a styrene block copolymer selected from the group consisting of polystyrene-polybutadiene-polystyrene (SBS), polystyrene-poly(ethylene-butene)-polystyrene (SEBS), polystyrene-poly(ethylene-propylene)-polystyrene (SEPS), polystyrene-polyisoprene-polystyrene (SIS), polystyrene-poly(isoprene-butadiene)-polystyrene (SIBS), and combinations thereof.

[0046] Styrene and α-methylstyrene block copolymers are preferably prepared by ionic polymerization of the relevant monomers and are available commercially, such as under the trade name Kraton sold by Kraton Polymers TM commercially available.

[0047] In a particularly preferred embodiment, the polyolefin (A) contains up to and including 50.0% by weight, preferably 10.0% to 40.% by weight, more preferably 15.0% to 35.0% by weight of recycled polyolefin, these weight percentages being based on the weight of the polyolefin (A), and the recycled polyolefin is preferably selected from recycled polypropylene, recycled polyethylene, recycled polystyrene, and combinations thereof.

[0048] The recycled polyolefin is derived from pre-consumer waste, post-consumer waste, or a combination thereof, preferably from post-consumer waste. In particular, the recycled polyolefin is derived from the mechanical recycling of at least one of the above waste streams. Methods for the mechanical recycling of post-consumer waste are known in the art, and recycled polyolefins are also available on the market.

[0049] The pigment (B) contained 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 less than 40.

[0050] The pigment (B) is organic, inorganic, organo-inorganic or a combination thereof; preferably the pigment is selected from: carbon black; oxides of metallic elements selected from iron, manganese, chromium and mixtures thereof; aniline black; and combinations thereof. More preferably, the polymer (B) is carbon black.

[0051] 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), these weight percentages being based on the sum of the weights of (A), (B), (C) and (D).

[0052] The pigment (B) is preferably blended with the other components of the colored thermoplastic polymer composition (I) as a masterbatch dispersed in a polymer carrier.

[0053] 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 more preferably from 3.0% to 6.0% by weight of mica (C) having a particle size equal to or less than 3500 microns, a D50 in the range from 400 microns to 2500 microns and an aspect ratio equal to or greater than 30.

[0054] More preferably, the mica (C) has at least one, preferably all of the following properties:

[0055] (i) a particle size equal to or less than 2000 microns, preferably equal to or less than 1700 microns, more preferably equal to or less than 1500 microns; a D50 in the range from 400 microns to 1500 microns, preferably from 600 microns to 1300 microns; and a D10 equal to or greater than 300 microns, preferably equal to or greater than 400 microns, still more preferably equal to or greater than 500 microns; and / or

[0056] (ii) an aspect ratio in the range from 30 to 90.

[0057] In a preferred embodiment, the mica (C) is coated mica which comprises a white inorganic pigment, still more preferably coated with a white inorganic pigment which is preferably selected from the group consisting of titanium dioxide, zinc oxide, zinc sulfide and combinations thereof.

[0058] In one embodiment, mica (C) has a particle size in the range of 3500 microns to 1 micron, preferably 2000 microns to 50 microns, more preferably 1700 microns to 100 microns, still more preferably 1500 microns to 200 microns.

[0059] Mica (C) is responsible for forming white inclusions into the dark polymer matrix. If the particle size is greater than 3500 microns, processing (such as extrusion) of the colored thermoplastic polymer composition (I) of the present disclosure is difficult, and clogging of the device may occur. If the mica has an average particle size D50 and optionally also D10 outside the above ranges, an insufficient amount of inclusions (bright spots / white dots) embedded in the colored thermoplastic matrix can be visually discerned, resulting in a perceived aesthetic effect.

[0060] In a preferred embodiment, the colored thermoplastic polymer composition (I) comprises 0.5 wt% to 7.0 wt%, preferably 1.0 wt% to 5.0 wt% of additive (D), where the amount of (D) is based on the total weight of (A), (B), (C), and (D).

[0061] Additive (D) preferably comprises at least one additive selected from the group consisting of light stabilizers (such as UV stabilizers), lubricants, and combinations thereof of the types commonly used in plastics. The colored thermoplastic polymer composition (I) containing at least one additive (D) has improved scratch resistance relative to the same composition lacking the additive.

[0062] Additional compounds preferably included in additive (D) are selected from the group consisting of nucleating agents, antistatic agents, antioxidants, slip agents, lubricants, antacids, melt stabilizers, coupling agents, and combinations thereof.

[0063] In an embodiment, the colored thermoplastic polymer composition (I) further comprises up to and including 40.0 wt%, preferably 1.0% to 40.0%, more preferably 5.0 wt% to 30.0%, still more preferably 10.0 wt% to 25.0% of inorganic filler (E), where the amount of (E) is based on the total amount of components (A), component (B), component (C), component (E), and optionally component (D).

[0064] Inorganic filler (E) is different from mica and is preferably selected from the group consisting of talc, glass fiber, glass beads, calcium carbonate, wollastonite, and combinations thereof, with talc being most preferred.

[0065] In a preferred embodiment, the colored thermoplastic polymer composition (I) comprises the following or consists of:

[0066] - 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), the thermoplastic polyolefin comprising:

[0067] - From 45.0% to 65.0% by weight of a propylene polymer fraction (A1), the propylene polymer fraction comprising: 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 (R1), wherein the amount of the recycled polypropylene (R1) is based on the weight of the propylene polymer fraction (A1);

[0068] - From 5.0% to 20.0% by weight of a virgin ethylene-α-olefin elastomer (A2);

[0069] - From 1.0% to 10.0% of a virgin styrene block copolymer (A3), the virgin styrene block copolymer 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, these weight percentages being based on the weight of the polystyrene (A3),

[0070] wherein the amount of (A1), the amount of (A2) and the amount of (A3) are based on the total weight of (A1), (A2) and (A3);

[0071] - 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) as described above, the pigment being preferably carbon black;

[0072] - 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 the mica (C) as described above;

[0073] - From 0.5% to 7.0% by weight, preferably from 1.0% to 5.0% by weight of a polymer additive (D), the polymer additive comprising additives selected from light stabilizers, lubricants and combinations thereof; and

[0074] - From 1.0% to 40.0%, more preferably from 5.0% to 30.0% by weight, still more preferably from 10.0% to 25.0% by weight of an inorganic filler (E), the inorganic filler being preferably talc,

[0075] wherein the amount of (A), the amount of (B), the amount of (C), the amount of (D) and the amount of (E) are based on the total weight of (A), (B), (C), (D) and (E).

[0076] The native polypropylene contained in the propylene polymer fraction (A1) is preferably selected from the group consisting of: native propylene homopolymers, native heterophasic propylene copolymers, and combinations thereof; more preferably the native polypropylene is a combination thereof.

[0077] The native propylene homopolymer preferably has a melt flow rate greater than 800 g / 10 min, preferably in the range of 1,000 to 2,000 g / 10 min, measured according to method ISO 1133-1:2011 (230 °C / 2.16 kg).

[0078] The native propylene homopolymer contained in the propylene polymer fraction (A1) is obtained by polymerizing propylene in the presence of any catalyst system suitable for obtaining highly stereoselective propylene homopolymers, such as Ziegler-Natta catalyst systems or metallocene catalysts of the types known in the art.

[0079] The native heterophasic propylene copolymer contained in the propylene polymer fraction (A1) preferably comprises:

[0080] - 30 wt% to 70 wt%, preferably 40 wt% to 70 wt% of fraction (a), which fraction contains a propylene polymer selected from propylene homopolymers, propylene copolymers, and combinations thereof, wherein the propylene copolymer contains up to and including 10.0 wt% of units derived from a comonomer, based on the weight of fraction (a), the comonomer being selected from ethylene, CH2=CHR α-olefins, and combinations thereof, wherein R is a linear or branched C2-C8 alkyl group, and wherein fraction (a) has a solubility in xylene at 25 °C equal to or less than 10.0 wt%, preferably equal to or less than 8.0 wt%, based on the weight of fraction (a); and

[0081] - 30 wt% to 70 wt%, preferably 30 wt% to 60 wt% of polymer fraction (b), which polymer fraction contains a copolymer of ethylene and a comonomer selected from propylene, CH2=CHR α-olefins, and combinations thereof, wherein R is a linear or branched C2-C8 alkyl group, wherein the ethylene copolymer contains 20.0 wt% to 50.0 wt%, preferably 25 wt% to 45 wt% of units derived from the comonomer, based on the weight of fraction (b), and wherein the amounts of (a) and (b) are referred to as the sum of the weights of (a)+(b).

[0082] The α-olefins contained in fraction (a) and fraction (b) are preferably independently selected from butene-1, hexene-1, octene-1, 4-methyl-1-pentene, and combinations thereof.

[0083] The native heterophasic propylene polymer contained in the propylene polymer fraction (A1) preferably has at least one, preferably all, of the following properties:

[0084] - fraction (a) consists essentially of a propylene homopolymer; and / or

[0085] - fraction (a) has a solubility in xylene at 25 °C equal to or less than 5.0 wt% determined according to the method described in the experimental section; and / or

[0086] - the comonomer contained in fraction (b) is propylene; and / or

[0087] - the melt flow rate measured according to method ISO 1133-1:2011 (230 °C / 2.16 kg) ranges from 0.5 to 40.0 g / 10 min, more preferably from 0.7 to 30.0 g / 10 min; and / or

[0088] - contains fractions ranging from 20 wt% to 50 wt% soluble in xylene at 25 °C, these weight percentages being based on the weight of the heterophasic propylene polymer, where the xylene-soluble fractions are measured as described in the experimental section; and / or

[0089] - a flexural modulus ranging from 500 MPa to 900 MPa measured according to method ISO 178:2010 on injection-molded test specimens.

[0090] The native heterophasic propylene polymer contained in the propylene polymer fraction (A1) is preferably obtained by polymerizing the relevant monomers in the liquid or gas phase in at least two polymerization stages, where the second and each subsequent polymerization stage is carried out in the presence of the polymer produced in the immediately preceding polymerization stage and the catalyst system used.

[0091] The polymerization of the relevant monomers is preferably carried out in the presence of a highly stereoselective Ziegler-Natta catalyst system, which catalyst system comprises:

[0092] (1) a solid catalyst component, which solid catalyst component comprises a magnesium halide support and a stereoregular internal donor, on which magnesium halide support there is a Ti compound having at least a Ti-halogen bond;

[0093] (2) optionally, but preferably, an aluminum-containing cocatalyst; and

[0094] (3) optionally, but preferably, an additional electron donor compound (external donor).

[0095] The solid catalyst component (1) preferably includes TiCl4 in an amount that ensures the presence of 0.5 wt% to 10 wt% of Ti relative to the total weight of the solid catalyst component (1).

[0096] The solid catalyst component (1) includes at least one stereoregular 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.

[0097] Suitable donors are esters of phthalic acid, such as those described in EP45977A2 and EP395083A2, especially diisobutyl phthalate, di-n-butyl phthalate, di-n-octyl phthalate, diphenyl phthalate, benzyl butyl phthalate, and combinations thereof.

[0098] Esters of aliphatic acids can also be selected from esters of malonic acid, such as those described in WO98 / 056830, WO98 / 056833, WO98 / 056834, esters of glutaric acid, such as those disclosed in WO00 / 55215, and esters of succinic acid, such as those disclosed in WO00 / 63261.

[0099] A particular type of diester is those esterified from aliphatic or aromatic diols, such as those described in WO2010 / 078494 and USP 7,388,061.

[0100] In a preferred embodiment, the internal donor is selected from 1,3-diether, such as those described in EP361493, EP728769, and WO02 / 100904.

[0101] A specific mixture of aliphatic or aromatic mono- or dicarboxylic acid esters and 1,3-diether, especially as disclosed in WO07 / 57160 and WO2011 / 061134, can be used as the internal donor.

[0102] The preferred magnesium halide carrier is magnesium dihalide.

[0103] The amount of the internal donor immobilized on the solid catalyst component (1) is 5 to 20 mol% relative to the magnesium dihalide.

[0104] The preparation of the catalyst component according to the general method is described in, for example, European patent applications US4,399,054, US4,469,648, WO98 / 44009A1, and EP395083A2.

[0105] 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.

[0106] In a preferred embodiment, the catalyst system includes an additional electron donor compound (3) (external electron donor) selected from silicon compounds, ethers, esters, amines, heterocyclic compounds (especially 2,2,6,6-tetramethylpiperidine) and ketones.

[0107] Preferred silicon compounds are selected from methylcyclohexyldimethoxysilane (C-donor), dicyclopentyldimethoxysilane (D-donor) and mixtures thereof.

[0108] The polymerization temperature preferably ranges from 20 °C to 100 °C, and for the process in the liquid phase, the polymerization pressure is preferably from 3.3 to 4.3 Mpa, and for the process in the gas phase, the polymerization pressure is preferably from 0.5 to 3.0 MPa.

[0109] The molecular weight of the polymer is adjusted by feeding a molecular weight regulator such as hydrogen into the polymerization reactor.

[0110] The amounts of component (a) and component (b) correspond to the split between the reactors.

[0111] The recycled propylene polymer (R1) is preferably derived from a pre-consumer waste stream, or a post-consumer waste stream or a combination thereof, in particular a mechanically recycled polypropylene derived from a post-consumer waste stream. The recycled propylene polymer (R1) has at least one, preferably all of the following properties:

[0112] - A melt flow rate in the range of 5.0 to 20.0 g / 10 min, preferably 8.0 to 17.0 g / 10 min, measured according to method ISO 1133-1:2011 (230 °C / 2.16 kg); and / or

[0113] - A flexural modulus in the range of 700 MPa to 1500 MPa, preferably 800 MPa to 1200 MPa, measured according to method ISO 178:2010 on an injection molded test specimen.

[0114] The virgin ethylene-α-olefin elastomer (A2) preferably contains 15.0 wt% to 50.0 wt% of a comonomer based on the ethylene-α-olefin elastomer, the comonomer being selected from propylene, CH2=CHR α-olefins and combinations thereof, where R is a straight-chain or branched C2-C8 alkyl group. The α-olefin is preferably selected from butene-1, hexene-1, octene-1, 4-methyl-1-pentene and combinations thereof.

[0115] The native ethylene-α-olefin elastomer (A2) is different from fraction (b).

[0116] The ethylene-α-olefin elastomer (A2) preferably has at least one, more preferably all of the following properties:

[0117] - A density in the range of 0.862 to 0.870 g / cm measured according to method ASTM D792; and / or 3 and / or

[0118] - A melt index in the range of 1.0 to 10.0 g / 10 min, preferably 3.0 to 8.0 g / 10 min, measured according to method ISO 1133-1:2011 (190 °C / 2.16 kg); and / or

[0119] - A tear strength in the range of 15.0 to 30.0 kN / m measured according to method ASTM D624; and / or

[0120] - A tensile modulus (100% secant) in the range of 0.5 MPa to 3.0 MPa measured according to method ASTM D638 on a compression-molded test specimen.

[0121] The ethylene copolymer (A2) can be commercially obtained, for example, under the trade name Engage, and is generally prepared using known polymerization methods, such as solution polymerization in the presence of a metallocene-based catalyst system. sold under the trade name Engage, and is generally prepared using known polymerization methods, such as solution polymerization in the presence of a metallocene-based catalyst system.

[0122] The styrene block copolymer (A3) preferably has at least one, preferably all of the following properties:

[0123] - A melt index in the range of 5.0 to 50.0 g / 10 min, preferably 10.0 to 40.0 g / 10 min, measured according to method ASTM D1238 (230 °C, 5.0 kg); and / or

[0124] - A Shore hardness A value equal to or lower than 60, preferably in the range of 30 to 65, measured according to method ASTM 2240 (10 s).

[0125] The colored thermoplastic polymer composition (I) of the present disclosure is prepared by blending the components in an extruder operating under conventional conditions (such as a temperature higher than the melting temperature of the thermoplastic polyolefin (A), preferably at a die temperature equal to or greater than 220 °C, preferably in the range of 210 °C to 270 °C), preferably a co-rotating or counter-rotating twin-screw extruder.

[0126] In a preferred embodiment, a method for preparing a colored thermoplastic polymer composition (I) comprises feeding the components into a twin-screw extruder, wherein mica (C) is fed via a side feeder.

[0127] The colored thermoplastic polymer composition (I) has at least one, preferably all of the following properties:

[0128] - A lightness value L* equal to or less than 30 measured in the CIELAB color space; and / or

[0129] - A lightness value L* equal to or greater than 0.5 measured in the CIELAB color space; and / or

[0130] - A melt flow rate equal to or greater than 10.0 g / 10 min, preferably in the range of 15.0 to 50.0 g / 10 min according to method ISO 1133-1:2011 (230 °C / 2.16 kg); and / or

[0131] - A flexural modulus equal to or greater than 1200 MPa, preferably in the range of 1350 MPa to 1800 MPa measured on injection molded test specimens according to method ISO 178:2010; and / or

[0132] - Impact resistance equal to or greater than 30 mJ / mm 2 preferably in the range of 35 to 50 mJ / mm 2 as measured by Charpy notched impact according to method AcN ISO 179 / 1eA at 23 °C and equal to or greater than 3.0 mJ / mm 2 preferably in the range of 3.5 to 7.0 mJ / mm 2 at -20 °C.

[0133] The lightness L* of the colored thermoplastic composition (I) is determined on a part of the composition where no inclusions are embedded.

[0134] The colored thermoplastic polymer composition (I) of the present disclosure is suitable for producing articles with a good balance of physical and mechanical properties and a pleasing aesthetic appearance.

[0135] Thus, on the other hand, the present disclosure relates to an article comprising the above-mentioned colored thermoplastic polymer composition (I), characterized in that the article comprises visually distinguishable inclusions embedded in a colored thermoplastic polymer matrix. Preferably, the article is an injection molded article, such as an interior or exterior part of a vehicle.

[0136] In a preferred embodiment, the article comprises at least 13,000 visually distinguishable inclusions per square meter (acceptable result), more preferably 14,000 to 20,000 visually distinguishable inclusions per square meter.

[0137] Preferably, the visually distinguishable inclusion has a nominal diameter equal to or greater than 150 microns, preferably in the range of 150 microns to 1,500 microns, where the nominal diameter corresponds to the diameter of the circle surrounding the visually distinguishable inclusion.

[0138] The visually distinguishable inclusion appears as a white dot embedded in a dark plastic matrix.

[0139] In another aspect, the present disclosure relates to the use of mica for obtaining visually distinguishable inclusions embedded in a colored thermoplastic polymer matrix, the mica having a particle size equal to or less than 3,500 microns, a D50 in the range of 400 microns to 2,500 microns, and an aspect ratio equal to or greater than 30, and the colored thermoplastic polymer matrix having a lightness L* value equal to or less than 40 measured in the CIELAB color space.

[0140] Mica (c) preferably has at least one, preferably all of the properties disclosed herein.

[0141] The thermoplastic polymer is preferably as described above.

[0142] The features characterizing the subject matter of the present disclosure are not inseparably linked to each other. Thus, the preferred range of one feature can be combined with the more or less preferred ranges of different features, regardless of their preferred levels.

[0143] Examples

[0144] The following examples are illustrative only and are not intended to limit the scope of the present disclosure in any way.

[0145] Characterization methods: The following methods are used to determine the properties indicated in the specification, claims, and examples.

[0146] Melt flow rate: Determined according to method 1133-1:2011.

[0147] Solubility of the propylene polymer in xylene at 25 °C: 2.5 g of the polymer sample and 250 ml of xylene are introduced into a glass flask equipped with a cooler and a magnetic stirrer. The temperature is raised to 135 °C within 30 minutes. The resulting clear solution is kept under reflux and stirred for another 30 minutes. The solution is cooled in two stages. In the first stage, the temperature is lowered to 100 °C in air with stirring for 10 to 15 minutes. 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 kept at 25 °C with stirring during the last 10 minutes. The solid formed is filtered on a fast filter paper (e.g., Whatman filter paper grade 4 or 541). 100 ml of the filtered solution (S1) is poured into a pre-weighed aluminum container, which is heated to 140 °C on a hot plate under a nitrogen stream to remove the solvent by evaporation. Then the container is kept in an oven at 80 °C under vacuum until a constant weight is reached. Then the amount of polymer soluble in xylene at 25 °C is calculated. The XS(I) and XS A values are determined experimentally. The fraction (XS B ) of the component (B) soluble in xylene at 25 °C can be calculated by the following formula:

[0148] XS = W(A) × (XS A ) + W(B) × (XS B )

[0149] where W(A) and W(B) are the relative amounts of component (A) and component (B), respectively, and W(A) + W(B) = 1.

[0150] Comonomer content: Determined by IR using a Fourier transform infrared spectrometer (FTIR). The spectrum of the polymer pressed film is recorded with absorbance relative to the wave number (cm-1). The following measurements are used to calculate the ethylene content:

[0151] - The area (At) of the combined absorption band between 4482 and 3950 cm-1, which is used for spectral normalization of the film thickness;

[0152] - Subtract the linear baseline and eliminate the remaining constant offset in the range of 790 - 660 cm-1;

[0153] The method is calibrated using a polymer standard based on 13C NMR analysis.

[0154] Sample Preparation: Use a hydraulic press to obtain thick sheets by pressing approximately 1 g of the sample between two aluminum foils. The pressing temperature is 180 ± 10 °C (356 °F), the pressure is approximately 10 kg / cm2, and the duration is approximately 1 minute (at least two pressing operations for each specimen). Cut a small portion from the sheet to mold the film. The recommended film thickness range is 0.02 cm to 0.05 cm.

[0155] Flexural Modulus: Determined according to method ISO 178:2010 on injection molded test specimens (80 x 10 x 4 mm) obtained according to method ISO 1873-2:2007.

[0156] Impact Resistance: Charpy notched impact AcN determined according to method ISO 179 / 1eA at 23 °C and at -20 °C.

[0157] Shrinkage Rate: Measured on injection molded plates. Ten test specimens are obtained by injection molding the thermoplastic composition in a 194,96 x 99,66 x 2,48 mm mold using a Krauss Maffei KM 160CX injection molding machine (mold temperature 35 °C, injection speed 33 mm / s, cooling time 30 minutes). Before testing, the specimens are allowed to stand at a temperature of 23 ± 2 °C for 48 hours. The dimensions of the specimens are measured with a micrometer and compared with the dimensions of a reference metal plate having the same mold dimensions. The shrinkage rate is calculated as the average of 10 measurements using the following formula:

[0158]

[0159] where

[0160] Ci is the shrinkage rate in a selected direction (longitudinal or transverse);

[0161] DR is the dimension of the reference metal plate in the selected direction; and

[0162] DS is the dimension of the sample in the selected direction.

[0163] Brightness: Measured in the CIELAB color space with a Datacolor 850 sphere spectrophotometer with a d / 8° geometry; illumination source: pulsed xenon filtered to approximate D65.

[0164] Particle Sizes D50 and D10: Measured by sieve analysis. By definition, D50 > D10.

[0165] Mica Aspect Ratio, Number of Inclusions / m 2 and Inclusion Size: Visually determined on injection molded articles using a digital microscope.

[0166] Raw Materials:

[0167] PP1: An acrylate polymer composition consisting essentially of: 42% by weight of fraction (a), which fraction comprises a propylene homopolymer; and 58% by weight of fraction (b), which fraction comprises a propylene-ethylene copolymer containing 42% by weight of units derived from ethylene, the acrylate polymer composition having a melt flow rate of 20.0 g / 10 min (230 °C, 2.16 Kg) and a solubility in xylene at 25 °C of 35.0% by weight, and having a flexural modulus greater than 600 MPa. The acrylate polymer composition PP1 is a reactor blend of fraction (a) and fraction (b) obtained by sequential polymerization of the relevant monomers in two stages.

[0168] PP2: An acrylate polymer composition comprising: 67% by weight of fraction (a), which fraction comprises a propylene homopolymer, fraction (a) having a solubility in xylene of less than 2.5% by weight; and 33% by weight of fraction (b), which fraction comprises a propylene-ethylene copolymer containing 33% by weight of units derived from ethylene, the acrylate polymer composition comprising 29.0% by weight of a fraction soluble in xylene and having a melt flow rate of 0.9 g / 10 min (230 °C, 2.16 Kg) and a flexural modulus of 800 MPa. The acrylate polymer composition PP2 is obtained as described in Example 4 of WO2004 / 087805.

[0169] PP3: A very high melt flow rate propylene homopolymer having a melt flow rate of 1800 g / 10 min (230 °C, 2.16 Kg) obtained by a metallocene catalyst system.

[0170] rPP: Having a melt flow rate of 12.0 g / 10 min (230 °C, 2.16 Kg), a density of 0.90 g / cm 3 (ISO1183) and a flexural modulus of 1100 MPa of mechanically recycled polypropylene.

[0171] Engage TM 11547: An ethylene-octene elastomer sold by Dow, having a melt index of 5.0 g / 10 min (ASTM D1238, 190 °C / 2.16 Kg), a tensile modulus 100% secant of 1.50 MPa (ASTM D638 on compression molded samples) and a tear strength of 22.0 kN / m (ASTM D624).

[0172] Kraton TM G1657:A linear triblock copolymer based on styrene and ethylene / butene, sold by Kraton Corp., has a polystyrene content of 13 wt%, a melt index of 22.0 G / 10 min (230 °C, 5.0 Kg), and a Shore hardness A value of 47 (ASTM D2240).

[0173] Luzenac talc T84 : Talc sold by Imerys.

[0174] Micacolor600SF : Mica sold by SOPAP (Société de Production et d’Adaptation des Polymères) in France. Micacolor 600SF has a particle size less than 1300 microns, a D50 of ca. 870 microns, and a D10 of ca. 630 microns.

[0175] Micavi 700 : Supplied by Cavisa, this mica has a particle size less than 900 microns, a D50 of ca. 450 microns, and a D10 of ca. 320 microns.

[0176] Mica-MU TM 800 : Mica sold by Imerys, having a particle size less than 900 microns, a D50 less than 300 microns, and a D10 less than 100 microns.

[0177] 944 : A light stabilizer (CAS No. 71878 - 19 - 8) sold by BASF.

[0178] 770 : Bis(2,2,6,6 - tetramethyl - 4 - piperidyl) sebacate light stabilizer sold by BASF.

[0179] Pigment concentrate : A masterbatch containing 70 wt% carbon black and 50 wt% polyolefin carrier.

[0180] Examples E1 and Comparative Examples CE2 to CE4

[0181] The colored thermoplastic polymer composition is prepared by blending the components shown in Table 1 in a ZSK - 70 extruder operating at a melt temperature in the range of 185 °C to 240 °C and at 200 rpm to 300 rpm.

[0182] The mica and talc are fed into the extruder via a side feeder.

[0183] The composition was injection molded into test specimens 80 x 10 x 4 mm obtained according to method ISO 1873-2:2007 and tested and visually inspected. The results are illustrated in Table 1.

[0184] Table 1

[0185]

[0186]

Claims

1. A colored thermoplastic polymer composition (I), the colored thermoplastic polymer composition having a lightness value L* equal to or less than 40 measured in the CIELAB color space, the colored thermoplastic polymer composition 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 mica, the mica having a particle size equal to or less than 3500 microns, a D50 in the range of 400 microns 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) according to 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 10.0% to 40.0% by weight, more preferably 15.0% to 35.0% by weight of recycled polyolefin, the weight percentages being based on the weight of the polyolefin (A), and the recycled polyolefin is 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 preceding claims, wherein the pigment (B) is selected from the following: carbon black; oxides of metal elements 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 preceding claims, the colored thermoplastic polymer composition comprising 0.1% to 1.5% by weight, preferably 0.1% to 1.5% by weight, more preferably 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 preceding claims, wherein the mica is coated mica.

7. The colored thermoplastic polymer composition (I) according to any one of the preceding claims, wherein the mica (C) has at least one, preferably all of the following properties: (i) A particle size equal to or less than 2000 microns, preferably equal to or less than 1700 microns, more preferably equal to or less than 1500 microns; a D50 in the range of 400 microns to 1500 microns, preferably 600 microns to 1300 microns; and a D10 equal to or greater than 300 microns, preferably equal to or greater than 400 microns, more preferably equal to or greater than 500 microns; and / or (ii) An aspect ratio in the range of 30 to 90.

8. The colored thermoplastic polymer composition (I) according to any one of the preceding claims, said colored thermoplastic polymer composition 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 the preceding claims, said colored thermoplastic polymer composition comprising from 0.5% to 7.0% by weight, preferably from 1.0% to 5.0% by weight of said 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 preceding claims, wherein said polymer additive (D) comprises additives selected from the group consisting of light stabilizers, lubricants and combinations thereof.

11. The colored thermoplastic polymer composition (I) according to any one of the preceding claims, said colored thermoplastic polymer composition 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 more 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 component (A), component (B), component (C), component (E) and optionally component (D).

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

13. The colored thermoplastic polymer composition (I) according to any one of the preceding claims, said colored thermoplastic polymer composition 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), said polyolefin comprising: - from 45.0% to 65.0% by weight of a propylene polymer fraction (A1), said propylene polymer fraction comprising: 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 (R1), wherein the amount of said recycled polypropylene (R1) is based on the weight of the propylene polymer fraction (A1); - from 5.0% to 20.0% by weight of a virgin elastomeric copolymer (A2) of ethylene and a comonomer, said comonomer being selected from the group consisting of propylene, CH2=CHR α-olefins and combinations thereof, wherein R is a straight or branched C2-C8 alkyl group; - 1.0% to 10.0% of a native styrene block copolymer (A3), said native styrene block copolymer comprising up to and including 30% by weight, preferably 5% to 30% by weight, more preferably 10% to 20% by weight of polymerized styrene, said weight percentages being based on the weight of the native styrene block copolymer (A3), wherein the amounts of (A1), (A2) and (A3) are based on the sum of the weights of (A1), (A2) and (A3); - 0.1% to 1.5% by weight, preferably 0.1% to 1.5% by weight, more preferably 0.3% to 1.0% by weight of a pigment (B), said pigment preferably being carbon black; - 1.0% to 10.0% by weight, preferably 2.0% to 8.0% by weight, more preferably 3.0% to 6.0% by weight of mica (C); - 0.5% to 7.0% by weight, preferably 1.0% to 5.0% by weight of a polymer additive (D), said polymer additive comprising additives selected from light stabilizers, lubricants and combinations thereof; and - 1.0% to 40.0%, more preferably 5.0% to 30.0% by weight, still more preferably 10.0% to 25.0% by weight of an inorganic filler (E), said inorganic filler preferably being 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 to 13, characterized in that, The article comprises visually distinguishable inclusions embedded in a colored thermoplastic polymer matrix.

15. Use of a mica for obtaining visually distinguishable inclusions embedded in a colored thermoplastic polymer matrix, said mica having a particle size equal to or less than 3500 microns, a D50 in the range of 400 microns to 2500 microns and an aspect ratio equal to or greater than 30, and said colored thermoplastic polymer matrix having a brightness L* value measured in the CIELAB color space equal to or less than 40.

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