Flame-retardant polypropylene composition

Abstract

The present invention relates to a polypropylene composition comprising a hybrid plastic polypropylene blend (PPB), a flame retardant (FR) and an anti-drip agent (AD), and an article comprising the polypropylene composition.

Description

Technical Field

[0001] This invention relates to a polypropylene composition comprising a blended plastic polypropylene blend (PPB), a flame retardant (FR), and an anti-dripping agent (AD), as well as articles comprising said polypropylene composition. Background Technology

[0002] Manufacturers of electric motors and power electronic components have traditionally used housings made of steel or die-cast aluminum. However, with many components now actively cooled, plastic solutions have emerged as a viable option for lightweight structures. Some existing alternatives are primarily based on PC / ABS or polyamide, engineering plastics that are expensive to produce and have a high CO2 footprint.

[0003] One mandatory requirement for electronic enclosures is a UL94 V-0 flame retardant rating when the thickness is less than 1.5 mm. Materials meeting these requirements are highly likely to be metals, halogen-based flame-retardant reinforced polymers, polymers with inherent flame-retardant properties, or non-halogen-based flame-retardant reinforced polymers, such as PC / ABS flame-retardant systems. Because these flame-retardant systems have high loading levels of flame-retardant additives, they can lead to decreased material performance and processing problems. Furthermore, anti-dripping agents are typically required to prevent dripping during combustion.

[0004] Propylene polymers can also be used as the base polymer in flame-retardant systems. Typically, glass fibers are used with polypropylene to achieve specific mechanical properties (e.g., stiffness). However, a major drawback of glass fiber reinforced polypropylene is its dimensional stability along the fiber direction and high warpage, especially when high-flow polypropylene is used as the base polymer. However, low warpage is crucial for particularly high-precision components such as battery holders.

[0005] In recent years, polymer waste has been recognized as a significant environmental and economic problem. Therefore, efforts have been made to recycle polymer waste and use recycled polymers in upgrading recycling applications. Consequently, a decline in mechanical properties is often observed when blending virgin and recycled materials.

[0006] WO2023 / 006797A1 discloses a flame-retardant polypropylene composition comprising high melt strength polypropylene made from virgin components as an anti-dripping agent. The composition meets the UL94 V-0 requirement and exhibits low warpage while maintaining high mechanical properties.

[0007] Surprisingly, it was found that by replacing the virgin propylene polymer used in the WO2023 / 006797A1 composition with a blend of polypropylene polypropylene (PPB) in an amount of up to 90% by weight of the total amount of the flame-retardant polypropylene composition, preferably derived from post-consumer waste, no loss of mechanical properties or UL94 test results was unexpectedly observed. Summary of the Invention

[0008] This invention relates to a polypropylene composition (C) comprising:

[0009] i) 30.0 to 90.0% by weight of mixed plastic polypropylene blends (PPB);

[0010] ii) 10.0 to 40.0% by weight of flame retardant (FR).

[0011] iii) 0.01 to 30.0% by weight of anti-dripping agent (AD), and

[0012] iv) 0 to 25.0% by weight of a propylene polymer (PP), wherein the propylene polymer (PP) has a melt flow rate MFR2 (230°C, 2.16 kg) of at least 15.0 g / 10 min as determined according to ISO 1133.

[0013] All weight percentages are based on the total weight of the polypropylene composition (C).

[0014] Furthermore, the present invention relates to an article comprising a polypropylene composition (C) as described above or below.

[0015] definition

[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. While any methods and materials similar to or equivalent to those described herein may be used in the practice of testing the invention, preferred materials and methods are described herein. In describing and claiming protection for this invention, the following terms will be used as defined below. Unless otherwise expressly stated, the terms “an,” “a,” etc., refer to more than one.

[0017] Blended plastics are defined as those containing small amounts of compounds not typically found in virgin polypropylene blends, such as polystyrene, polyamides, polyesters, wood, paper, limonene, aldehydes, ketones, fatty acids, metals, and / or long-term decomposition products of stabilizers. Virgin polypropylene blends refer to blends derived directly from the production process without any intermediate uses.

[0018] By definition, “hybrid plastics” can be equivalent to polystyrene and / or polyamide-6 and / or limonene and / or fatty acids in detectable amounts.

[0019] Therefore, unlike virgin polymers, blended plastics can originate from both post-consumer waste and industrial waste. Post-consumer waste refers to objects that have completed at least one use cycle (or life cycle), meaning they have fulfilled their first intended purpose. In contrast, industrial waste refers to manufacturing or processing waste that typically does not reach consumers.

[0020] The term "virgin" refers to newly produced materials and / or objects before their first use, which have not yet been recycled.

[0021] The term “recycled material” as used in this article refers to materials derived from “recycled waste” through reprocessing.

[0022] Polymer blends are mixtures of two or more polymer components. Typically, blends are prepared by mixing two or more polymer components. A suitable mixing procedure known in the art is post-polymerization blending. Post-polymerization blending can be a dry blending of polymer components (e.g., polymer powders and / or composite polymer granules) or a melt blending of polymer components by melt mixing.

[0023] A blend of polypropylene plastics indicates that the blend mainly contains polypropylene, but contains small amounts of other plastics.

[0024] A blend of polyethylene plastics indicates that the blend mainly contains polyethylene, but contains small amounts of other plastics.

[0025] Recycled blends, especially post-consumer recycled blends, are almost always mixed plastic blends, reflecting the efficiency of sorting in existing recycling processes.

[0026] Polypropylene refers to a polymer consisting of propylene-derived units in a content of more than 50 mol%.

[0027] Polyethylene refers to a polymer consisting of units derived from ethylene with a content of more than 50 mol%.

[0028] Propylene homopolymers are polymers primarily composed of propylene monomer units. Due to impurities, especially during commercial polymerization, propylene homopolymers may contain up to 0.1 mol% of comonomer units, preferably up to 0.05 mol% of comonomer units, and most preferably up to 0.01 mol% of comonomer units.

[0029] The presence of multiphase properties can be readily determined by the number of glass transition points (e.g., in dynamic mechanical analysis (DMA)) and / or by high-resolution microscopy (e.g., scanning electron microscopy (SEM), transmission electron microscopy (TEM), or atomic force microscopy (AFM)).

[0030] The term "XCS" refers to the cold soluble fraction of xylene (XCS wt%) determined at 25°C according to ISO 16152. The term "XCI" refers to the cold insoluble fraction of xylene (XCI wt%) determined at 25°C according to ISO 16152.

[0031] Reactor blends are blends produced in two or more reactors in series or in a reactor with two or more reaction compartments. Reactor blends can also be produced by blending in solution. Reactor blends differ from compounds produced by melt extrusion.

[0032] Unless otherwise stated, "%" refers to weight % (wt.-%). Detailed Implementation

[0033] This invention relates to a polypropylene composition (C), said polypropylene composition (C) comprising:

[0034] i) 30.0 to 90.0% by weight of mixed plastic polypropylene blends (PPB);

[0035] ii) 10.0 to 40.0% by weight of flame retardant (FR).

[0036] iii) 0.01 to 30.0% by weight of anti-dripping agent (AD), and

[0037] iv) 0 to 25.0% by weight of a propylene polymer (PP), wherein the propylene polymer (PP) has a melt flow rate MFR2 (230°C, 2.16 kg) of at least 15.0 g / 10 min as determined according to ISO 1133.

[0038] All weight percentages are based on the total weight of the polypropylene composition (C).

[0039] Preferably, the total amount of the mixed plastic polypropylene blend (PPB), flame retardant (FR), anti-dripping agent (AD), and optional propylene polymer (PP) accounts for at least 85.0% by weight of the polypropylene composition (C), preferably at least 87.5% by weight, and more preferably at least 90.0% by weight.

[0040] The polypropylene composition (C) according to the present invention may further contain additives (ADDs), such as acid scavengers, antioxidants, colorants, light stabilizers, slip agents, anti-scratch agents, dispersants, processing aids, lubricants, pigments, etc.

[0041] The additives do not include the necessary anti-dripping agent (AD).

[0042] Preferably, the polypropylene composition (C) does not contain any fillers, such as fibers (e.g., glass fibers), talc, or wollastonite.

[0043] In one embodiment, the polypropylene composition comprises a blended plastic polypropylene blend (PPB), a flame retardant (FR), an anti-dripping agent (AD), an optional propylene polymer (PP), and an optional additive (ADD).

[0044] Therefore, the preferred polypropylene composition (C) comprises the following components, and more preferably consists of the following components:

[0045] i) 30.0 to 90.0% by weight, preferably 35.0 to 84.0% by weight, more preferably 40.0 to 79.0% by weight of mixed plastic polypropylene blends (PPB).

[0046] ii) 10.0 to 40.0% by weight, 15.0 to 35.0% by weight, more preferably 20.0 to 32.5% by weight of flame retardant (FR).

[0047] iii) 0.01 to 30.0% by weight, 0.05 to 27.5% by weight, more preferably 0.1 to 25.0% by weight of an anti-dripping agent (AD), and

[0048] iv) 0 to 25.0% by weight, preferably 0 to 22.5% by weight, more preferably 0 to 20.0% by weight of a propylene polymer (PP), wherein the propylene polymer (PP) has a melt flow rate MFR2 (230°C, 2.16 kg) of at least 15.0 g / 10 min as determined according to ISO 1133.

[0049] v) 0 to 15.0% by weight, preferably 0 to 12.5% ​​by weight, more preferably 0 to 10.0% by weight of additives (ADD).

[0050] All weight percentages are based on the total weight of the polypropylene composition (C).

[0051] Preferably, the total amount of the blended polypropylene blend (PPB), flame retardant (FR), anti-dripping agent (AD), and optional propylene polymer (PP) and optional additive (ADD) accounts for at least 90% by weight of the polypropylene composition (C), more preferably 100% by weight.

[0052] In another embodiment, based on the total weight of the polypropylene composition (C), the polypropylene composition (C) may also contain up to 10.0% by weight (e.g., 1.5 to 10% by weight) of additional polymer components, such as polypropylene and / or polyethylene, preferably polyethylene, such as high-density polyethylene.

[0053] Therefore, the preferred polypropylene composition (C) comprises the following components, and more preferably consists of the following components:

[0054] i) 30.0 to 90.0% by weight, preferably 35.0 to 84.0% by weight, more preferably 40.0 to 79.0% by weight of mixed plastic polypropylene blends (PPB).

[0055] ii) 10.0 to 40.0% by weight, 15.0 to 35.0% by weight, more preferably 20.0 to 32.5% by weight of flame retardant (FR).

[0056] iii) 0.01 to 30.0% by weight, 0.05 to 27.5% by weight, more preferably 0.1 to 25.0% by weight of an anti-dripping agent (AD), and

[0057] iv) 0 to 25.0% by weight, preferably 0 to 22.5% by weight, more preferably 0 to 20.0% by weight of a propylene polymer (PP), wherein the propylene polymer (PP) has a melt flow rate MFR2 (230°C, 2.16 kg) of at least 15.0 g / 10 min as determined according to ISO 1133.

[0058] v) 0 to 15.0% by weight, preferably 0 to 12.5% ​​by weight, more preferably 0 to 10.0% by weight of additives (ADD).

[0059] vi) 0 to 10.0% by weight, preferably 1.5 to 10.0% by weight, more preferably 2.5 to 9.0% by weight of additional polymer components,

[0060] All weight percentages are based on the total weight of the polypropylene composition (C).

[0061] Preferably, the total amount of the blended polypropylene blend (PPB), flame retardant (FR), anti-dripping agent (AD), optional propylene polymer (PP), optional additive (ADD), and additional polymer components accounts for at least 90% by weight of the polypropylene composition (C), more preferably 100% by weight.

[0062] Preferably, the melt flow rate (MFR2) of the polypropylene composition (C) according to the invention, as determined according to ISO 1133 at 2.16 kg and 230°C, is 2.5 to 20.0 g / 10 min, more preferably 3.0 to 15.0 g / 10 min, and more preferably 4.0 to 12.5 g / 10 min.

[0063] Regarding mechanical properties, the preferred polypropylene composition (C) has a tensile modulus of at least 1250 MPa, for example 1250 to 3000 MPa, preferably 1500 to 2500 MPa, and more preferably 1650 to 2250 MPa, as determined by ISO 527-1A at 23°C.

[0064] Furthermore, the preferred polypropylene composition (C) has a tensile strength of at least 12 MPa, for example 12 to 40 MPa, preferably 15 to 35 MPa, more preferably 17 to 30 MPa, as determined by ISO 527-1A at 23°C.

[0065] Furthermore, the preferred polypropylene composition (C) has a tensile stress at break of at least 2.3%, for example 2.3 to 7.5%, preferably 2.5 to 7.0%, and more preferably 2.7 to 6.0%, as determined by ISO 527-1A at 23°C.

[0066] Furthermore, or as an alternative to the previous paragraph, it is preferred that the polypropylene composition (C) has a Charpy notched impact strength of at least 1.0 kJ / m², as determined according to ISO 179 1eA at 23°C. 2 For example, 1.0 to 10.0 kJ / m 2 The preferred concentration is 1.2 to 8.5 kJ / m³. 2 More preferably 1.5 to 7.5 kJ / m 2 .

[0067] Preferably, when the test is performed using a 1.5 mm thick specimen and applying condition 1 (i.e., the specimen is conditioned for 48 hours at a constant room temperature of 23 ± 2°C and 50 ± 10% humidity) according to the method described under “Measuring Methods” herein, the polypropylene composition (C) meets the requirements of the UL 94 V-0 standard for the flammability safety of plastic materials.

[0068] Furthermore, when the test is performed using a 1.5 mm thick specimen and applying condition 1 (i.e., the specimen is conditioned in an air-circulating oven at 70 ± 1 °C for 168 hours and then cooled in a desiccator at room temperature for at least 4 hours) according to the method described under “Measuring Methods” in this document, the polypropylene composition (C) preferably meets the requirements of the UL 94 V-0 standard for the flammability safety of plastic materials.

[0069] The polypropylene composition (C) is preferably obtained by blending (preferably melt blending) a plastic polypropylene blend (PPB), a flame retardant (FR), an anti-dripping agent (AD), and optionally a propylene polymer (PP) and optional additives (ADD).

[0070] The following sections will describe in more detail the blended plastic polypropylene (PPB) blend, flame retardant (FR), anti-dripping agent (AD), and propylene polymer (PP).

[0071] Polypropylene blends (PPB)

[0072] The polypropylene composition (C) comprises a blend of polypropylene polymers (PPB).

[0073] Polypropylene blends (PPB) are recycled materials rich in polypropylene, meaning they contain significantly more polypropylene than polyethylene. Polypropylene-rich recycled waste streams can be obtained, for example, from the automotive industry, particularly because some automotive parts (such as bumpers) are sources of fairly pure polypropylene material in recycled streams.

[0074] Preferably, the polypropylene-rich recycled material is obtained from recycled waste using plastic recycling processes known in the art. Such recycled materials are commercially available, for example from Corepla (Italian Union for the Collection, Recycling, and Regeneration of Packaging Plastic Waste), Resource Plastics Corp. (Brampton, Ontario), Kruschitz GmbH, Plastics and Recycling (Austria), Vogt Plastik GmbH (Germany), Mtm ​​Plastics GmbH (Germany), Borealis AG (Austria), and others. Non-exhaustive examples of polypropylene-rich recycled materials include Purpolen. ® PP (Mtm PlasticsGmbH) and Borcycle TM M (Borealis AG).

[0075] During the recycling process, any reasonable measures are typically taken to reduce / remove any components other than polyethylene and polypropylene, provided that the final application or use recommends such measures; however, other components are usually present in small amounts.

[0076] Other components of this type include polystyrene (PS), polyamide (PA), and polyethylene terephthalate (PET), all of which are present in the lowest possible amounts, preferably below the detection limit.

[0077] The melt flow rate (MFR2) of the polypropylene blend (PPB) is preferably in the range of 15.0 to 40.0 g / 10 min, more preferably 16.5 to 35.0 g / 10 min, and even more preferably 17.5 to 30.0 g / 10 min.

[0078] Furthermore, the density of the polypropylene blend (PPB) (determined according to ISO 1183) is preferably 900 to 1030 kg / m³. 3 More preferably, it is 905 to 1020 kg / m 3 More preferably, it is 910 to 1010 kg / m³ 3 .

[0079] Polypropylene blends (PPB) can be characterized using CRYSTEX QC analysis. CRYSTEX QC analysis yields and quantifies the crystalline fraction (CF) and soluble fraction (SF), and allows for analysis of monomer and comonomer content, as well as intrinsic viscosity (iV).

[0080] Polypropylene blends (PPB) preferably exhibit one or all of the following properties in CRYSTEX QC analysis:

[0081] • The content of the crystal fraction (CF), as determined by CRYSTEX QC analysis, is in the range of 80.0 to 96.0% by weight, preferably 82.5 to 95.5% by weight, more preferably 85.0 to 95.0% by weight; and

[0082] • The soluble fraction (SF) content, as determined by CRYSTEX QC analysis, is in the range of 4.0 to 20.0% by weight, preferably 4.5 to 17.5% by weight, and more preferably 5.0 to 15.0% by weight.

[0083] The crystalline fraction (CF) preferably has one or more of the following characteristics, and preferably all of the following characteristics:

[0084] • Through quantitative 13 The ethylene content (C2(CF)) determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy is 1.0 to 15.0% by weight, preferably in the range of 1.5 to 12.5% ​​by weight, more preferably 2.0 to 11.5% by weight; and / or

[0085] • The intrinsic viscosity (iV(CF)) measured in naphthalene at 135°C according to DIN ISO 1628 / 1 is 0.9 to 2.1 dl / g, preferably in the range of 1.0 to 2.0 dl / g, and more preferably in the range of 1.1 to 1.9 dl / g.

[0086] The soluble fraction (SF) preferably has one or more of the following characteristics, and preferably all of the following characteristics:

[0087] • Through quantitative 13The ethylene content (C2(SF)) determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy is in the range of 15.0 to 40.0% by weight, preferably 20.0 to 37.5% by weight, more preferably 22.5 to 35.0% by weight; and / or

[0088] • The intrinsic viscosity (iV(SF)) in naphthalene, measured at 135°C according to DIN ISO 1628 / 1, is 0.9 to 2.2 dl / g, preferably in the range of 1.0 to 2.1 dl / g, and more preferably in the range of 1.1 to 2.0 dl / g.

[0089] The blended plastic polypropylene blend (PPB) preferably contains 2.5 to 15.0% by weight, more preferably 3.0 to 13.5% by weight, and even more preferably 3.5 to 12.5% ​​by weight of ethylene-derived units.

[0090] The inorganic residue content of the polypropylene blend (PPB) determined by calcination analysis according to DIN ISO 1172:1996 is preferably from 0.05 to 3.0% by weight, more preferably from 0.5 to 2.5% by weight, and most preferably from 1.0 to 2.5% by weight.

[0091] The polypropylene blend (PPB) is preferably derived from post-industrial or post-consumer waste, with post-consumer waste being the most preferred source.

[0092] The limonene content (determined by solid-phase microextraction HS-SPME-GC-MS) of the polypropylene blend (PPB) is preferably between 1 and 250 mg / m³. 3 Within the range.

[0093] The presence of limonene indicates that the blended plastic polypropylene (PPB) is derived from post-consumer waste.

[0094] Other indicators of the recyclability of polypropylene blends (PPB) include the presence of other polymers (such as polystyrene and polyamide-6) and the presence of fatty acids.

[0095] Therefore, it is also preferred that the mixed plastic polypropylene blend (PPB) contains one or more of polystyrene, polyamide-6 and fatty acids, and preferably contains each of polystyrene, polyamide-6 and fatty acids.

[0096] Polypropylene blends (PPB) are preferably available in the following CIELAB color space ( ):

[0097] i) The value is 50.0 to 97.0, more preferably 80.0 to 97.0;

[0098] ii) The range is from -5.0 to 0.0;

[0099] iii) The range is from 0.0 to 22.0 (excluding 22.0).

[0100] The tensile modulus of the polypropylene blend (PPB) is preferably from 1,000 to 1,750 MPa, more preferably from 1,100 to 1,600 MPa, and even more preferably from 1,150 to 1,500 MPa.

[0101] Furthermore, the Charpy notched impact strength (CNIS, at 23°C) of the polypropylene blend (PPB) is preferably 3.0 to 7.5 kJ / m. 2 More preferably, it is 4.0 to 7.0 kJ / m 2 .

[0102] Before being blended with other components used to prepare the polypropylene composition (C), the blended plastic polypropylene blend (PPB) can be aerated (e.g., as described in EP3786190A1) to remove volatile components.

[0103] Flame retardant (FR)

[0104] The polypropylene composition (C) contains a flame retardant (FR). The flame retardant (FR) may also be a mixture of two or more flame retardants (FR).

[0105] The flame retardant product can be any flame retardant product suitable for polypropylene resins.

[0106] Preferably, the flame retardant (FR) is halogen-free. In other words, the preferred flame retardant (FR) does not contain any organic or inorganic compounds containing halogen atoms. As used herein, the term "halogen" refers to elements in Group 17 of the periodic table.

[0107] Preferably, the polypropylene composition (C) contains a nitrogen-containing flame retardant (FR).

[0108] Preferably, the nitrogen-containing flame retardant (FR) comprises at least one nitrogen-containing phosphate, more preferably at least one organic nitrogen-containing phosphate. Preferably, the organic nitrogen-containing phosphate is a phosphate of a heterocyclic C3-C6- (more preferably C3-C4-) alkyl or aryl compound containing at least one nitrogen atom.

[0109] According to a preferred embodiment of the present invention, the nitrogen-containing flame retardant (FR) comprises a first nitrogen-containing phosphate (FR1) and a second nitrogen-containing phosphate (FR2) that is different from the first nitrogen-containing phosphate (FR1).

[0110] Preferably, the first nitrogen-containing phosphate (FR1) and the second nitrogen-containing phosphate (FR2) are organic nitrogen-containing phosphates. Particularly preferably, the first nitrogen-containing phosphate (FR1) and the second nitrogen-containing phosphate (FR2) are phosphates of heterocyclic C3-C6- (more preferably C3-C4-) alkyl or aryl compounds containing at least one nitrogen atom.

[0111] Preferably, the first nitrogen-containing phosphate (FR1) is an organic nitrogen-containing polyphosphate. More preferably, the first nitrogen-containing phosphate (FR1) is a polyphosphate of a heterocyclic C3-C6- (more preferably C3-C4-) aryl compound containing at least one nitrogen atom. Particularly preferably, the first nitrogen-containing phosphate (FR1) is a melamine polyphosphate.

[0112] Preferably, the second nitrogen-containing phosphate (FR2) is an organic nitrogen-containing diphosphate. More preferably, the second nitrogen-containing phosphate (FR2) is a diphosphate of a heterocyclic C3-C6- (more preferably C3-C4-) alkyl compound containing at least one nitrogen atom (e.g., two nitrogen atoms). Particularly preferably, the second nitrogen-containing phosphate (FR2) is piperazine pyrophosphate.

[0113] According to a preferred embodiment of the present invention, the weight ratio between the first nitrogen-containing phosphate (FR1) and the second nitrogen-containing phosphate (FR2) is in the range of 60:40 to 40:60.

[0114] Suitable nitrogen-containing flame retardants (FRs) are preferably commercially available. A very suitable example of a commercially available nitrogen-containing flame retardant (FR) is the flame retardant product manufactured and supplied by SULI and sold under the trade name Phlamoon-1090A.

[0115] As described above, based on the total weight of the polypropylene composition (C), the polypropylene composition (C) of the present invention contains 10.0 to 40.0% by weight, preferably 18.0 to 35.0% by weight, more preferably 20.0 to 38.0% by weight, even more preferably 20.0 to 30.0% by weight, and even more preferably 20.0 to 27.0% by weight, for example 20.0 to 25.0% by weight of flame retardant (FR).

[0116] In this document, the amount of flame retardant (FR) refers to the amount of flame retardant (FR) provided by the manufacturer based on the total weight of the polypropylene composition (C). Therefore, the flame retardant (FR) may contain small amounts of other components, such as additives, flame retardant synergists, and / or carrier media. It should therefore be understood that these other components are included in the amount of flame retardant (FR).

[0117] Anti-dripping agent (AD)

[0118] The polypropylene composition (C) of the present invention further comprises an anti-dripping agent (AD).

[0119] The term “anti-dripping agent” as used herein refers to an additive that prevents or reduces the dripping effect of polymer materials under UL94 test conditions. During UL94 testing, it is necessary to observe whether the sample drips and, if so, whether the drips ignite. The rating of a polymer product in the UL94 vertical burning test depends on the burning time and the dripping phenomenon. The burning time after the ignition source is removed determines whether the polymer is rated V0, V1, or unrated (unacceptable). The dripping phenomenon distinguishes between V2 and V1 ratings. If the burning material drips and ignites cotton placed under the test sample, the polymer product will be rated V2. Clearly, the dripping phenomenon is important for the UL94 vertical test (see Y. Wang et al., Journal of Fire Sciences 2012, 30(6), 477-501).

[0120] Anti-dripping agents are typically polymeric materials, such as halogenated polymers (e.g., fluorinated polyolefins), high melt strength polymers (e.g., high melt strength polypropylene), or biopolymers (e.g., lignin).

[0121] In a preferred embodiment, the anti-dripping agent (AD) is a halogenated polymer, such as a halogenated polyolefin, preferably a fluorinated polyolefin, such as polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and polychlorotrifluoroethylene (PCTFE). Polytetrafluoroethylene (PTFE) is the most preferred.

[0122] In the embodiments where the anti-dripping agent (AD) is a halogenated polymer (preferably polytetrafluoroethylene (PTFE)), the amount of anti-dripping agent (AD) in the polypropylene composition (C) is typically 0.01 to 5.0% by weight, preferably 0.05 to 2.5% by weight, and more preferably 0.1 to 1.5% by weight, based on the total weight of the polypropylene composition (C).

[0123] According to another preferred embodiment of the invention, the anti-dripping agent (AD) is halogen-free. In other words, preferably, the anti-dripping agent (AD) does not contain any organic or inorganic compounds containing halogen atoms. The term "halogen" as used herein refers to elements in Group 17 of the periodic table.

[0124] In the embodiment described, the anti-dripping agent (AD) is preferably high melt strength polypropylene (HMS-PP).

[0125] High melt strength polypropylene is branched, and therefore differs from linear polypropylene in that its main chain contains side chains, while unbranched polypropylene (i.e., linear polypropylene) does not. These side chains have a significant impact on the rheology of polypropylene. Therefore, linear polypropylene and high melt strength polypropylene can be clearly distinguished by their flow behavior under stress.

[0126] Therefore, melt strength (e.g., F) 30 Melt strength (F) depends on the general flowability of high melt strength polypropylene, such as the melt flow rate (MFR2). The higher the MFR2 of high melt strength polypropylene, the higher its F... 30 The lower the melt strength. However, compared to linear polypropylene, high melt strength polypropylene has a higher F... 30 The melt strength to MFR2 ratio is higher than that of linear polypropylene.

[0127] Branching can be achieved by using a specific catalyst (i.e., a specific single-active-site catalyst) or by chemical modification. For the preparation of branched polypropylene obtained by using a specific catalyst, refer to EP1892264. For branched polypropylene obtained by chemical modification, refer to EP0879830A1. In this case, branched polypropylene is also referred to as high melt strength polypropylene.

[0128] The branching index g' defines the degree of branching and is related to the number of branches in the polymer. Preferably, the branching index g' of high melt strength polypropylene (HMS-PP) as determined by GPC is less than or equal to 0.95, more preferably less than or equal to 0.9, and even more preferably less than or equal to 0.85, for example less than or equal to 0.8.

[0129] F of high melt strength polypropylene (HMS-PP) 30 The melt strength is preferably at least 2.5 cN, more preferably 2.5 to 50 cN.

[0130] In addition, the v of high melt strength polypropylene (HMS-PP) 30 The melt extensibility is preferably at least 200 mm / s, more preferably 200 to 500 mm / s.

[0131] F 30 Melt strength and v 30 Melt elongation was measured according to ISO 16790:2005.

[0132] Furthermore, preferably, the melt flow rate (MFR2) of the high melt strength polypropylene (HMS-PP) as measured according to ISO 1133 (230°C, 2.16 kg) is in the range of 0.5 to 25.0 g / 10 min.

[0133] Furthermore, high melt strength polypropylene (HMS-PP) can be further defined by its strain hardening factor (SHF). Therefore, preferably, high melt strength polypropylene (HMS-PP) has a strain hardening factor of 3.0 s. -1The strain hardening factor (SHF) measured at a strain rate of 2.5 and a Hencky strain is at least 1.7, more preferably at least 1.9, even more preferably in the range of 1.9 to 7.0, and even more preferably in the range of 1.9 to 6.5.

[0134] In one embodiment, high melt strength polypropylene (HMS-PP) has the following characteristics:

[0135] The melt flow rate MFR2 (230°C, 2.16 kg) is 0.5 to 7.5 g / 10 min, preferably 1.0 to 5.0 g / 10 min, and more preferably 1.8 to 3.0 g / 10 min, as measured according to ISO 1133.

[0136] At least 10 cN, preferably 10 to 50 cN of F 30 Melt strength; and

[0137] At least 200 mm / s, preferably 200 to 300 mm / s v 30 Melt elongation.

[0138] F 30 Melt strength and v 30 Melt elongation was measured according to ISO 16790:2005.

[0139] In another embodiment, high melt strength polypropylene (HMS-PP) has the following characteristics:

[0140] The melt flow rate MFR2 (230°C, 2.16 kg) measured according to ISO 1133 is greater than 7.5 and less than 11.0 g / 10 min, preferably 8.5 to 10.5 g / 10 min, and more preferably 9.0 to 10.0 g / 10 min.

[0141] At least 2.5 cN, preferably at least 5.0 cN, more preferably 5.0 to 25 cN of F 30 Melt strength; and

[0142] At least 200 mm / s, preferably 200 to 500 mm / s v 30 Melt elongation.

[0143] F 30 Melt strength and v 30 Melt elongation was measured according to ISO 16790:2005.

[0144] Preferably, the melting temperature Tm of the high melt strength polypropylene (HMS-PP) is at least 130°C, more preferably at least 135°C, and most preferably at least 140°C. The crystallization temperature Tc is preferably at least 120°C.

[0145] In addition, high melt strength polypropylene (HMS-PP) can be high melt strength random propylene copolymer (R-HMS-PP) or high melt strength propylene homopolymer (H-HMS-PP), preferably high melt strength propylene homopolymer (H-HMS-PP).

[0146] For the purposes of this invention, the term "propylene homopolymer" refers to polypropylene that is substantially composed of propylene units (i.e., at least 97 mol%, preferably at least 98 mol%, more preferably at least 99 mol%, and most preferably at least 99.8 mol%). In a preferred embodiment, only propylene units are detectable in the propylene homopolymer.

[0147] If high melt strength polypropylene (HMS-PP) is a high melt strength random propylene copolymer (R-HMS-PP), then it contains monomers copolymerized with propylene, such as comonomers, such as ethylene and / or C4 to C4 copolymers. 12 α-olefins, especially ethylene and / or C4 to C5 10 α-Olefins, such as 1-butene and / or 1-hexene. Preferably, the high melt strength random propylene copolymer (R-HMS-PP) comprises, in particular, monomers selected from ethylene, 1-butene, and 1-hexene copolymerized with propylene. More specifically, the high melt strength random propylene copolymer (R-HMS-PP) contains units derived from ethylene and / or 1-butene in addition to propylene. In a preferred embodiment, the high melt strength random propylene copolymer (R-HMS-PP) contains only units derived from ethylene and propylene. The comonomer content in the high melt strength random propylene copolymer (R-HMS-PP) is preferably more than 0.2 and less than 10.0 mol%, more preferably more than 0.5 and less than 7.0 mol%.

[0148] It is worth mentioning in this regard that high melt strength polypropylene (HMS-PP), which is a high melt strength propylene homopolymer (H-HMS-PP) or a high melt strength random propylene copolymer (R-HMS-PP), can also contain unsaturated monomers that are different from the comonomers defined for high melt strength random propylene copolymers (R-HMS-PP). In other words, high melt strength propylene homopolymers (H-HMS-PP) or high melt strength random propylene copolymers (R-HMS-PP) can contain unsaturated monomers, such as bifunctional unsaturated monomers and / or polyfunctional unsaturated low molecular weight polymers (as defined in detail below), which are different from propylene, ethylene, and other C4 to C6 polymers. 12 α-Olefins. Therefore, for high melt strength polypropylene (HMS-PP), the definitions of homopolymers and copolymers actually refer to unmodified polypropylene used to obtain melt strength polypropylene (HMS-PP) through chemical modification, as described in detail below.

[0149] As previously mentioned, high melt strength polypropylene (HMS-PP) is a modified polypropylene. Therefore, high melt strength polypropylene (HMS-PP) can also be defined by its method of acquisition. High melt strength polypropylene (HMS-PP) is preferably the result of treating unmodified polypropylene with a thermally decomposable free radical forming agent and / or ionizing radiation. However, in this case, the risk of degradation of the unmodified polypropylene is high, which is undesirable. Therefore, modification is preferably achieved by using bifunctional unsaturated monomers and / or polyfunctional unsaturated low molecular weight polymers as bridging units for chemical bonding. Suitable methods for obtaining high melt strength polypropylene (HMS-PP) are disclosed, for example, in EP0787750, EP0879830A1 and EP0890612A2. All documents are incorporated herein by reference. Therefore, the amount of peroxide is preferably in the range of 0.05 to 3.00 wt.% based on unmodified polypropylene.

[0150] Therefore, in a preferred embodiment, high melt strength polypropylene (HMS-PP) comprises:

[0151] (a) derived from the following units (when the high melt strength polypropylene (HMS-PP) is a high melt strength propylene homopolymer (H-HMS-PP)):

[0152] (i) Propylene, and

[0153] (ii) Bifunctional unsaturated monomers and / or polyfunctional unsaturated low molecular weight polymers;

[0154] or

[0155] (b) Units derived from the following (when the high melt strength polypropylene (HMS-PP) is a high melt strength random propylene copolymer (R-HMS-PP):

[0156] (i) Propylene,

[0157] (ii) Ethylene and / or C4 to C 10 α-olefins, such as 1-butene and / or 1-hexene, preferably ethylene, and

[0158] (iii) Bifunctional unsaturated monomers and / or polyfunctional unsaturated low molecular weight polymers.

[0159] The term "bifunctional or polyfunctional unsaturated" as used above preferably refers to the presence of two or more non-aromatic double bonds, such as in divinylbenzene, cyclopentadiene, or polybutadiene. Only these difunctional or polyfunctional unsaturated compounds, which can preferably be polymerized via free radicals, are used. The unsaturated sites in these compounds are in a chemically bonded state that is not actually "unsaturated," because each double bond is used to form a covalent bond with the polymer chain of the unmodified polypropylene.

[0160] Bifunctional unsaturated monomers and / or polyfunctional unsaturated low molecular weight polymers (preferably number average molecular weight (M) n The reaction of polypropylene with unmodified polypropylene (≤10000 g / mol, synthesized from one and / or multiple unsaturated monomers) can be carried out in the presence of thermal free radical forming agents (e.g., decomposable free radical forming agents, such as thermally decomposable peroxides) and / or ionizing radiation or microwave radiation.

[0161] Bifunctional unsaturated monomers can be:

[0162] • Divinyl compounds, such as divinylaniline, m-divinylbenzene, p-divinylbenzene, divinylpentane, and divinylpropane;

[0163] • Allyl compounds, such as allyl acrylate, allyl methacrylate, allyl methyl maleate, and allyl vinyl ether;

[0164] • Dienes, such as 1,3-butadiene, chloroprene, cyclohexadiene, cyclopentadiene, 2,3-dimethylbutadiene, heptaadiene, hexadiene, isoprene and 1,4-pentadiene;

[0165] • Aromatic and / or aliphatic bis(maleimide) bis(limonimide) and mixtures of these unsaturated monomers.

[0166] The particularly preferred bifunctional unsaturated monomers are 1,3-butadiene, isoprene, dimethylbutadiene, and divinylbenzene.

[0167] Multifunctional unsaturated low molecular weight polymers (preferably number average molecular weight (M) n (≤10000g / mol) can be synthesized from more than one unsaturated monomer.

[0168] Examples of such low molecular weight polymers are:

[0169] • Polybutadiene, especially polybutadiene in which different microstructures (i.e. 1,4-cis, 1,4-trans and 1,2-(vinyl)) in the polymer chain are mainly in the 1,2-(vinyl) configuration;

[0170] • A copolymer of butadiene and styrene having 1,2-(vinyl) in the polymer chain.

[0171] Preferred low molecular weight polymers are polybutadiene, especially polybutadiene in which more than 50.0% by weight of butadiene is in the 1,2-(vinyl) configuration.

[0172] High melt strength polypropylene (HMS-PP) may contain more than one difunctional unsaturated monomer and / or a polyfunctional unsaturated low molecular weight polymer. More preferably, the total amount of difunctional unsaturated monomer and polyfunctional unsaturated low molecular weight polymer in the high melt strength polypropylene (HMS-PP) is from 0.01 to 10.0% by weight.

[0173] As described above, it is preferable to use bifunctional unsaturated monomers and / or polyfunctional unsaturated low molecular weight polymers in the presence of thermally decomposable free radical forming agents.

[0174] The preferred thermal decomposition free radical forming agent is a peroxide. More preferably, the thermal decomposition free radical forming agent is selected from acyl peroxides, alkyl peroxides, hydroperoxides, peresters, and peroxycarbonates.

[0175] The following peroxides are particularly preferred:

[0176] Acyl peroxides: benzoyl peroxide, 4-chlorobenzoyl peroxide, 3-methoxybenzoyl peroxide and / or methylbenzoyl peroxide.

[0177] Alkyl peroxides: allyl tert-butyl peroxide, 2,2-bis(tert-butylperoxybutane), 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, n-butyl-4,4-bis(tert-butylperoxy)valerate, diisopropylaminomethyltert-pentyl peroxide, dimethylaminomethyltert-pentyl peroxide, diethylaminomethyltert-butyl peroxide, dimethylaminomethyltert-butyl peroxide, 1,1-bis(tert-pentylperoxy)cyclohexane, tert-pentyl peroxide, tert-butylcumyl peroxide, tert-butyl peroxide and / or 1-hydroxybutyl-n-butyl peroxide.

[0178] Peresters and peroxycarbonates: butyl peracetate, cumyl peracetate, cumyl perpropionate, cyclohexyl peracetate, di-tert-butyl peradiate, di-tert-butyl perazelate, di-tert-butyl perglutarate, di-tert-butyl perphthalate perthalate), di-tert-butyl persecanoate, 4-nitrocumyl perpropionate, 1-phenylethyl perbenzoate, nitrophenylperbenzoate, tert-butylbicyclo-(2,2,1)heptane percarboxylic acid, tert-butyl-4-methyl perbutyrate, tert-butylcyclobutane percarboxylic acid, tert-butylcyclohexyl peroxycarboxylic acid, tert-butylcyclopentyl percarboxylic acid, tert-butylcyclopropane percarboxylic acid, tert-butyl dimethyl percinnamate, tert-butyl-2-(2,2-diphenylvinyl) perbenzoate, tert-butyl-4-methoxy perbenzoate, tert-butyl perbenzoate, tert-butylcarboxylic acid ring Hexane, tert-butyl pernaphthalate, tert-butyl peroxyisopropyl carbonate, tert-butyl pertoluate, tert-butyl-1-phenylcyclopropane percarboxylate, tert-butyl-2-propenyl perpenten-2-o-octanoate, tert-butyl-1-methylcyclopropyl percarboxylate, tert-butyl-4-nitrobenzene peracetate, tert-butyl-nitrobenzene peroxycarbamate, tert-butyl-N-succinimide percarboxylate, tert-butyl percrotonate, tert-butyl permaleate, tert-butyl permethacrylate, tert-butyl peroctanoate, tert-butyl peroxyisopropyl carbonate, tert-butyl perisobutyrate, tert-butyl peracrylate, and / or tert-butyl perpropionate.

[0179] A mixture of the above-mentioned free radical forming agents can also be considered.

[0180] Preferably, the unmodified polypropylene is a propylene homopolymer.

[0181] Following preparation, high melt strength polypropylene (HMS-PP) can undergo modification steps to further modify the polymer. Such modification steps include, for example, grafting, in which one or more functional comonomers are grafted onto the polypropylene chain; and visbreaking, in which the molecular weight of the polypropylene is reduced by mixing the molten polymer with a free radical generator (e.g., peroxide) in an extruder. These steps are well known to those skilled in the art and relevant references can be found in the literature.

[0182] In embodiments where the anti-dripping agent (AD) is preferably high melt strength polypropylene (HMS-PP), the amount of anti-dripping agent (AD) in the polypropylene composition (C) is typically 10.0 to 30.0% by weight, preferably 12.5 to 27.5% by weight, and more preferably 15.0 to 25.0% by weight, based on the total weight of the polypropylene composition (C).

[0183] Propylene polymer (PP)

[0184] The flame-retardant polypropylene composition (C) may optionally include a propylene polymer (PP). The propylene polymer (PP) may also be a mixture of two or more propylene polymer (PP) components.

[0185] The melt flow rate (MFR2) of propylene polymer (PP) as determined according to ISO 1133 (230°C, 2.16 kg) is at least 15.0 g / 10 min, for example in the range of 15.0 to 300 g / 10 min.

[0186] Particularly preferably, the melt flow rate MFR2 (230°C, 2.16 kg) of the propylene polymer (PP) (determined according to ISO 1133) is at least 45.0 g / 10 min, for example in the range of 45.0 to 300 g / 10 min, preferably in the range of 60.0 to 200 g / 10 min, and more preferably in the range of 80.0 to 120 g / 10 min.

[0187] Propylene polymer (PP) can be a homopolymer or copolymer of propylene. Furthermore, propylene polymer (PP) can contain more than one different propylene polymer (PP) component.

[0188] If the propylene polymer (PP) is a copolymer of propylene, preferably, the comonomer is selected from ethylene and / or C4 to C8 α-olefins. Particularly preferably, the comonomer is ethylene. For a propylene polymer (PP) containing more than one (e.g., two) different propylene polymer components (all propylene copolymers), preferably all propylene polymer components contain the same comonomer, such as ethylene.

[0189] Preferably, the propylene polymer (PP) is a copolymer of propylene with ethylene and / or at least one other C4 to C8 α-olefin.

[0190] The comonomer content (such as ethylene content) of the propylene polymer (PP) is preferably 2.0 to 25.0 mol%, more preferably 4.0 to 20.0 mol%, and even more preferably 6.0 to 15.0 mol%, for example 6.2 to 12.0 mol%.

[0191] In a preferred embodiment of the present invention, the propylene polymer (PP) is a multiphase propylene copolymer (HECO) comprising:

[0192] i) Matrix (M), which is a propylene polymer;

[0193] ii) Elastomer (E), which is a copolymer containing units derived from propylene and ethylene and / or C4 to C8 α-olefins.

[0194] In this invention, the term "multiphase" generally refers to an elastomer that is (finely) dispersed within a matrix. In other words, the elastomer forms inclusions within the matrix. Therefore, the matrix contains (finely) dispersed inclusions that are not part of the matrix, and these inclusions contain the elastomer. According to the invention, the term "inclusion" preferably indicates that the matrix and the inclusions form different phases within the multiphase polypropylene, and that the inclusions can be observed, for example, by a high-resolution microscope (e.g., an electron microscope or a scanning force microscope).

[0195] Multiphase propylene copolymers (HECO) can be characterized using CRYSTEX QC analysis. CRYSTEX QC analysis yields crystalline fractions (CF) and soluble fractions (SF), which can be quantified and analyzed in terms of monomer and comonomer content, as well as intrinsic viscosity (iV).

[0196] Multiphase propylene copolymers (HECO) are preferably characterized by one or all of the following properties in CRYSTEX QC analysis:

[0197] • The content of the crystal fraction (CF), as determined by CRYSTEX QC analysis, is in the range of 80.5 to 92.0% by weight, preferably in the range of 82.0 to 90.0% by weight, and more preferably in the range of 83.0 to 86.0% by weight; and

[0198] • The soluble fraction (SF) content, as determined by CRYSTEX QC analysis, is in the range of 8.0 to 19.5% by weight, preferably in the range of 10.0 to 18.0% by weight, and more preferably in the range of 13.0 to 17.0% by weight.

[0199] The crystalline fraction (CF) preferably has one or more, preferably all of the following characteristics:

[0200] • Through quantitative 13 The ethylene content (C2(CF)) determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy is 0.1 to 5.0 wt%, preferably 0.2 to 4.0 wt%, more preferably 0.5 to 3.0 wt%; and / or

[0201] • The intrinsic viscosity (iV(CF)) measured in naphthalene at 135°C according to DIN ISO 1628 / 1 is less than 1.8 dl / g, preferably 0.8 to 1.6 dl / g, more preferably 0.9 to 1.3 dl / g.

[0202] The soluble fraction (SF) preferably has one or more, preferably all of the following characteristics:

[0203] • Through quantitative 13The ethylene content (C2(SF)) determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy is in the range of 25.0 to 45.0 wt%, preferably in the range of 27.5 to 43.0 wt%, and more preferably in the range of 30.0 to 42.0 wt%; and / or

[0204] • The intrinsic viscosity (iV(SF)) measured in naphthalene at 135°C according to DIN ISO 1628 / 1 is 1.50 to 4.00 dl / g, preferably 1.60 to 3.00 dl / g, and more preferably 1.70 to 2.50 dl / g.

[0205] In a particular embodiment, the intrinsic viscosity (iV(SF)) of the multiphase propylene copolymer (HECO) measured in naphthalene at 135°C according to DIN ISO 1628 / 1 is preferably 2.00 to 4.00 dl / g, more preferably 2.30 to 3.70 dl / g, and more preferably 2.50 to 3.30 dl / g.

[0206] The multiphase propylene copolymer (HECO) preferably contains 2.5 to 12.5% ​​by weight, more preferably 4.0 to 10.0% by weight, and even more preferably 5.0 to 7.5% by weight of ethylene-derived units.

[0207] The intrinsic viscosity ratio (IV(SF) / IV(CF)) of the soluble fraction to the crystalline fraction is preferably greater than 1.0, more preferably 1.3 to 2.5, and even more preferably 1.4 to 2.0.

[0208] The ethylene content ratio (C2(SF) / C2(CF)) of the soluble fraction to the crystalline fraction is preferably in the range of 7.5 to 22.5, more preferably in the range of 10.0 to 20.0, and even more preferably in the range of 15.0 to 17.5.

[0209] Multiphase propylene copolymers (HECO) preferably possess one or more, preferably all of the following properties:

[0210] • A melting temperature Tm of 155 to 175°C, more preferably 157 to 172°C, and even more preferably 160 to 170°C; and / or

[0211] • A crystallization temperature Tc of 115 to 135°C, more preferably 117 to 132°C, and even more preferably 119 to 130°C;

[0212] The melting temperature and the crystallization were both determined by differential scanning calorimetry (DSC).

[0213] Multiphase propylene copolymers (HECO) preferably exhibit a good balance of mechanical properties, impact resistance, and thermal stability.

[0214] The tensile modulus of the multiphase propylene copolymer (HECO) is preferably 1200 to 1600 MPa, more preferably 1250 to 1550 MPa, and even more preferably 1300 to 1500 MPa.

[0215] Furthermore, the Charpy notched impact strength (CNIS at 23°C) of the multiphase propylene copolymer (HECO) is preferably from 1.0 to 7.5 kJ / m. 2 More preferably, it is 2.0 to 5.0 kJ / m 2 .

[0216] Preferably, the multiphase propylene copolymer (HECO) consists only of propylene units and ethylene units.

[0217] Although not measured, the sum of the unit content of propylene (C3) in the soluble fraction (SF) and the unit content of ethylene (C2) in the soluble fraction (SF) is preferably 100 by weight.

[0218] The content of propylene (C3)-derived units in the soluble fraction (SF) is preferably 55.0 to 75.0% by weight, more preferably 57.0 to 72.5% by weight, and even more preferably 58.0 to 70.0% by weight.

[0219] Although not measured, the sum of the unit content of propylene (C3) in the crystalline fraction (CF) and the unit content of ethylene (C2) in the crystalline fraction (CF) is preferably 100 by weight.

[0220] The content of propylene (C3)-derived units in the crystalline fraction (CF) is preferably 95.0 to 99.9% by weight, more preferably 96.0 to 99.8% by weight, and even more preferably 97.0 to 99.5% by weight.

[0221] The total content of propylene (C3)-derived units in the multiphase propylene copolymer (HECO) is preferably 87.5 to 97.5% by weight, more preferably 90.0 to 96.0% by weight, and even more preferably 92.5 to 95.0% by weight.

[0222] Multiphase propylene copolymer (HECO) is preferably a native polymer.

[0223] Multiphase propylene copolymers suitable as multiphase propylene copolymers (HECO) are commercially available.

[0224] Before blending with other components used to prepare the polypropylene composition (C), the multiphase propylene copolymer (HECO) can be ventilated (e.g., as described in EP3786190A1) to remove volatile components.

[0225] Additives (ADD)

[0226] In addition to blended polypropylene (PPB), flame retardants (FR), anti-dripping agents (AD), and optional propylene polymers (PP), the polypropylene composition (C) may also contain additives (ADD). Typical additives include acid scavengers, antioxidants, colorants, light stabilizers, slip agents, scratch inhibitors, dispersants, processing aids, lubricants, pigments, etc.

[0227] The additives do not include the necessary anti-dripping agent (AD).

[0228] Preferably, the additive (ADD) does not include fillers such as fibers (e.g., glass fibers), talc, or wollastonite.

[0229] Based on the total weight of the polypropylene composition (C), the content of additives in the polypropylene composition (C) of the present invention generally does not exceed 15.0% by weight, preferably in the range of 0.1% to 12.5% ​​by weight, and more preferably in the range of 0.1% to 10.0% by weight.

[0230] Such additives are commercially available, for example, as described in Hans Zweifel's Handbook of Plastic Additives (6th edition, 2009, pp. 1141-1190).

[0231] Furthermore, the term "additive (AD)" according to the present invention also includes carrier materials, particularly polymer carrier materials.

[0232] Polymer carrier materials

[0233] Preferably, based on the weight of the polypropylene composition (C), the polypropylene composition (C) contains no more than 5.0% by weight, preferably no more than 3.0% by weight, and more preferably no more than 2.0% by weight of other polymers different from the blended plastic polypropylene (PPB), anti-dripping agent (AD), and optional propylene polymer (PP). Any polymer used as an additive (ADD) carrier material is not included in the amount of the polymer compound shown in this invention, but is included in the amount of the corresponding additive.

[0234] The polymer carrier material for the additive (ADD) is a carrier polymer to ensure uniform distribution in the polypropylene composition (C) of the present invention. The polymer carrier material is not limited to a specific polymer. The polymer carrier material can be an ethylene homopolymer, an ethylene copolymer obtained from ethylene and α-olefin comonomers (e.g., C3 to C8 α-olefin comonomers), a propylene homopolymer, and / or a propylene copolymer obtained from propylene and α-olefin comonomers (e.g., ethylene and / or C4 to C8 α-olefin comonomers). Preferably, the polymer carrier material does not contain monomer units that can be derived from styrene or its derivatives.

[0235] Implementation

[0236] In a preferred embodiment, the polypropylene composition comprises, preferably, the following components:

[0237] i) 55.0 to 90.0% by weight, preferably 62.5 to 84.0% by weight, more preferably 66.5 to 79.0% by weight of mixed plastic polypropylene blends (PPB);

[0238] ii) 10.0 to 40.0% by weight, 15.0 to 35.0% by weight, more preferably 20.0 to 32.5% by weight of flame retardant (FR);

[0239] iii) 0.01 to 5.0% by weight, preferably 0.05 to 2.5% by weight, more preferably 0.1 to 1.5% by weight of an anti-dripping agent, said anti-dripping agent being a halogenated polyolefin, preferably a fluorinated polyolefin, and most preferably polytetrafluoroethylene (PTFE); and

[0240] iv) 0% by weight of a propylene polymer (PP) with a melt flow rate (MFR2, 230°C, 2.16 kg) of at least 15.0 g / 10 min as determined according to ISO 1133; and

[0241] v) 0 to 15.0% by weight, preferably 0 to 12.5% ​​by weight, more preferably 0 to 10.0% by weight of additives (ADD).

[0242] All weight percentages are based on the total weight of the polypropylene composition (C).

[0243] In the described embodiment, the polypropylene composition (C) is free of propylene polymer (PP) and contains halogenated polymers, such as halogenated polyolefins, preferably fluorinated polyolefins, such as polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and polychlorotrifluoroethylene (PCTFE). Polytetrafluoroethylene (PTFE) is the most preferred.

[0244] Because of the presence of a small amount (not exceeding 5.0% by weight) of halogenated polyolefin as an anti-dripping agent (AD), a very high weight percentage (at least 55.0% by weight) of mixed plastic polypropylene blend (PPB) can be added to the polypropylene composition (C).

[0245] Surprisingly, the best results were observed in the UL94 test when all the propylene polymer (PP) was replaced with a blend of plastic polypropylene (PPB) in the polypropylene composition (C).

[0246] In a second preferred embodiment, the polypropylene composition comprises, preferably, the following components:

[0247] i) 30.0 to 80.0% by weight, preferably 35.0 to 70.0% by weight, more preferably 40.0 to 60.0% by weight of mixed plastic polypropylene blend (PPB).

[0248] ii) 10.0 to 40.0% by weight, 15.0 to 35.0% by weight, more preferably 20.0 to 32.5% by weight of flame retardant (FR);

[0249] iii) 10.0 to 30.0% by weight, preferably 12.5 to 27.5% by weight, more preferably 15.0 to 25.0% by weight of an anti-dripping agent, wherein the anti-dripping agent is high melt strength polypropylene (HMS-PP).

[0250] iv) 0% by weight of a propylene polymer (PP) with a melt flow rate (MFR2, 230°C, 2.16 kg) of at least 15.0 g / 10 min as determined according to ISO 1133; and

[0251] v) 0 to 15.0% by weight, preferably 0 to 12.5% ​​by weight, more preferably 0 to 10.0% by weight of additives (ADD).

[0252] All weight percentages are based on the total weight of the polypropylene composition (C).

[0253] In the second embodiment, the polypropylene composition (C) does not contain propylene polymer (PP).

[0254] Furthermore, in the second embodiment, the polypropylene composition (C) is free of fluoropolymers. In particular, it is preferred that the content of fluoropolymers in the polypropylene composition (C) is no more than 0.5% by weight, more preferably no more than 0.1% by weight, and even more preferably no more than 0.01% by weight, for example, no more than 0.001% by weight. Particularly preferably, no fluoropolymers are used in the production of the polypropylene composition (C).

[0255] As used herein, the term "fluoropolymer" refers to a polymer compound that contains fluorine atoms. Examples of fluoropolymers are polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and polychlorotrifluoroethylene (PCTFE).

[0256] High melt strength polypropylene (HMS-PP) has been introduced into polypropylene compositions (C) to replace fluoropolymers as anti-dripping agents.

[0257] High melt strength polypropylene (HMS-PP) is introduced into the polypropylene composition (C) in an amount of at least 10.0% by weight so that at least 30.0% by weight of mixed plastic polypropylene blend (PPB) can be added to the polypropylene composition (C).

[0258] Surprisingly, good results were observed in the UL94 test when all the propylene polymer (PP) was replaced with a blended plastic polypropylene blend (PPB) in the polypropylene composition (C).

[0259] In the third embodiment, the polypropylene composition comprises, preferably, the following components:

[0260] i) 30.0 to 69.0% by weight, preferably 35.0 to 60.0% by weight, more preferably 40.0 to 50.0% by weight of mixed plastic polypropylene blend (PPB).

[0261] ii) 10.0 to 40.0% by weight, 15.0 to 35.0% by weight, more preferably 20.0 to 32.5% by weight of flame retardant (FR);

[0262] iii) 10.0 to 30.0% by weight, preferably 12.5 to 27.5% by weight, more preferably 15.0 to 25.0% by weight of an anti-dripping agent, wherein the anti-dripping agent is high melt strength polypropylene (HMS-PP).

[0263] iv) 11.0 to 25.0% by weight, preferably 12.5 to 22.5% by weight, more preferably 15.0 to 20.0% by weight of a propylene polymer (PP), wherein the propylene polymer (PP) has a melt flow rate MFR2 (230°C, 2.16 kg) of at least 15.0 g / 10 min as determined according to ISO 1133; and

[0264] v) 0 to 15.0% by weight, preferably 0 to 12.5% ​​by weight, more preferably 0 to 10.0% by weight of additives (ADD).

[0265] All weight percentages are based on the total weight of the polypropylene composition (C).

[0266] Furthermore, in the third embodiment, the polypropylene composition may also contain additional polymer components, such as polypropylene and / or polyethylene, preferably polyethylene, such as high-density polyethylene, wherein the content of the additional polymer components is not more than 10.0% by weight, for example, 1.5 to 10% by weight, based on the total weight of the polypropylene composition (C).

[0267] Therefore, in the third embodiment, the polypropylene composition (C) preferably comprises the following components, and more preferably consists of the following components:

[0268] i) 30.0 to 69.0% by weight, preferably 35.0 to 60.0% by weight, more preferably 40.0 to 50.0% by weight of mixed plastic polypropylene blend (PPB).

[0269] ii) 10.0 to 40.0% by weight, 15.0 to 35.0% by weight, more preferably 20.0 to 32.5% by weight of flame retardant (FR);

[0270] iii) 10.0 to 30.0% by weight, preferably 12.5 to 27.5% by weight, more preferably 15.0 to 25.0% by weight of an anti-dripping agent, wherein the anti-dripping agent is high melt strength polypropylene (HMS-PP).

[0271] iv) 11.0 to 25.0% by weight, preferably 12.5 to 22.5% by weight, more preferably 15.0 to 20.0% by weight of a propylene polymer (PP), wherein the propylene polymer (PP) has a melt flow rate MFR2 (230°C, 2.16 kg) of at least 15.0 g / 10 min as determined according to ISO 1133; and

[0272] v) 0 to 15.0% by weight, preferably 0 to 12.5% ​​by weight, more preferably 0 to 10.0% by weight of additives (ADD).

[0273] vi) 0 to 10.0% by weight, preferably 1.5 to 10.0% by weight, more preferably 2.5 to 9.0% by weight of additional polymer components.

[0274] All weight percentages are based on the total weight of the polypropylene composition (C).

[0275] In the third embodiment, the polypropylene composition (C) is free of fluoropolymers. In particular, it is preferred that the content of fluoropolymers in the polypropylene composition (C) is no more than 0.5% by weight, more preferably no more than 0.1% by weight, and even more preferably no more than 0.01% by weight, for example, no more than 0.001% by weight. Particularly preferably, no fluoropolymers are used in the production of the polypropylene composition (C).

[0276] As used herein, the term "fluoropolymer" refers to a polymer compound that contains fluorine atoms. Examples of fluoropolymers are polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and polychlorotrifluoroethylene (PCTFE).

[0277] High melt strength polypropylene (HMS-PP) has been introduced into polypropylene compositions (C) to replace fluoropolymers as anti-dripping agents.

[0278] High melt strength polypropylene (HMS-PP) is introduced into the polypropylene composition (C) in an amount of at least 10.0% by weight so that at least 30.0% by weight of mixed plastic polypropylene blend (PPB) can be added to the polypropylene composition (C).

[0279] In the embodiments described, it has been found that when a small amount (11.0 to 25.0% by weight) of propylene polymer (PP) is introduced into the polypropylene composition (C), good results are observed in the UL94 test, while the polypropylene composition (C) has a high melt flow rate, which ensures good processability in injection molding.

[0280] Therefore, particularly preferably, the melt flow rate (MFR2) of the propylene polymer (PP) is at least 45.0 g / 10 min, for example in the range of 45.0 to 300 g / 10 min, preferably in the range of 60.0 to 200 g / 10 min, and more preferably in the range of 80.0 to 120 g / 10 min. The introduction of the propylene polymer (PP) also shifts the balance of mechanical properties towards the slightly more rigid polypropylene composition (C).

[0281] More preferably, the propylene polymer (PP) in the third embodiment is a multiphase propylene copolymer, such as the multiphase propylene copolymers described above and below.

[0282] Products

[0283] The present invention also relates to an article comprising a polypropylene composition (C) as defined above or below. In particular, the present invention relates to an article comprising at least 60% by weight, more preferably at least 80% by weight, even more preferably at least 90% by weight, for example at least 95% by weight or at least 99% by weight of a polypropylene composition (C) as defined above or below. In a particularly preferred embodiment, the present invention relates to an article composed of a polypropylene composition (C) as defined above or below.

[0284] Preferably, the article is an automotive article in the field of electronic components, such as cable insulation, electrical equipment housing, and part and container of power electronic components in automotive parts and household appliance parts, etc.

[0285] The present invention will now be described in further detail through the embodiments provided below. Example

[0286] A. Measurement Method

[0287] Unless otherwise defined, the following terms and measurement methods apply to the general description of the invention above and the embodiments described below.

[0288] MFR2 (230°C) is measured according to ISO 1133 (230°C, 2.16 kg load).

[0289] MFR2 (190°C) is measured according to ISO 1133 (190°C, 2.16 kg load).

[0290] Quantitative analysis of microstructure using NMR spectroscopy

[0291] Quantitative nuclear magnetic resonance (NMR) spectroscopy is used to quantify the comonomer content and comonomer sequence distribution of polymers. A Bruker Advance III 400 NMR spectrometer was used to record quantitative data in solution. 13 C{ 1 HNMR spectroscopy, targeting 1 H and 13 The operating frequencies of C are 400.15 MHz and 100.62 MHz, respectively. All spectra are used... 13 A C-optimized 10mm wide-temperature probe was used for recording at 125°C, and nitrogen was used for all pneumatic devices. Approximately 200 mg of material was dissolved in 3 ml of 1,2-tetrachloroethane along with chromium acetylacetone (Cr(acac)3). d 2 (TCE- d 2A 65 mM relaxant solution was obtained in the solvent (Singh, G., Kothari, A., Gupta, V., Polymer Testing 28 5 (2009), 475). To ensure solution homogeneity, the NMR tubes were further heated in a rotary oven for at least 1 hour after initial sample preparation in a heating block. The tubes were then inserted into a magnet and rotated at 10 Hz. This setup was chosen primarily to obtain the high resolution and quantification required for accurate ethylene content quantification. Standard single-pulse excitation was employed, with no NOE, using an optimized pulse tip angle, a 1-second cyclic delay, and a two-stage WALTZ16 decoupling scheme (Zhou, Z., Kuemmerle, R., Qiu, X., Redwine, D., Cong, R., Taha, A., Baugh, D. Winniford, B., J. Mag. Reson. 187 (2007) 225; Busico, V., Carbonniere, P., Cipullo, R., Pellecchia, R., Severn, J., Talarico, G., Macromol. Rapid Commun. 2007, 28, 1128). A total of 6144 (6 k) transient signals were acquired for each spectrum.

[0292] Processing and quantitative integration using proprietary computer programs. 13 C{ 1 ¹H NMR spectra were used, and the relevant quantitative properties were determined from the integration. Chemical shifts of the solvent were used, with all chemical shifts indirectly referenced to the central methylene group of the ethylene block (EEE) at 30.00 ppm. This method allows for comparable references even in the absence of this structural unit. Characteristic signals corresponding to ethylene incorporation were observed (Cheng, HN, Macromolecules 17 (1984), 1950).

[0293] For polypropylene homopolymers, all chemical shifts are internally referenced to the methyl isotactic pentamematic group (mmmm) at 21.85 ppm.

[0294] Characteristic signals corresponding to regional defects (Resconi, L., Cavallo, L., Fait, A., Piemontesi, F., Chem. Rev. 2000, 100, 1253; Wang, WJ., Zhu, S., Macromolecules 33 (2000), 1157; Cheng, HN, Macromolecules 17 (1984), 1950) or comonomers were observed.

[0295] Stereoregularity distribution was quantified by integrating the methyl region between 23.6 and 19.7 ppm, with corrections made for any sites unrelated to the target stereo sequence (Busico, V., Cipullo, R., Prog. Polym. Sci. 26 (2001) 443; Busico, V., Cipullo, R., Monaco, G., Vacatello, M., Segre, AL, Macromoleucles 30 (1997) 6251).

[0296] Specifically, by subtracting representative regional defects and comonomer integrals from specific integral regions of the stereo sequence, the quantitative influence of regional defects and comonomers on the stereoregularity distribution is corrected.

[0297] Isothetic regularity was determined at the pentamematic level and reported as the percentage of isothetic pentamematic (mmmm) sequences relative to all pentamematic sequences:

[0298]

[0299] The presence of defects in the 2,1 equatorial region is indicated by the presence of two methyl sites at 17.7 and 17.2 ppm, and confirmed by other characteristic sites.

[0300] No characteristic signals corresponding to other types of regional defects were observed (Resconi, L., Cavallo, L., Fait, A., Piemontesi, F., Chem. Rev. 2000, 100, 1253).

[0301] The amount of defects in the 2,1 equatorial region was quantified using the average integral of two characteristic methyl sites at 17.7 and 17.2 ppm:

[0302] P 21e = ( I e6 + I e8 ) / 2

[0303] The amount of primary propylene insertion 1,2 was quantified based on the methyl region, after correction for sites within this region unrelated to primary insertion and primary insertion sites not located in this region:

[0304] P 12 = I CH3 + P 12e

[0305] The total amount of propylene is quantified as the sum of primary inserted propylene and all other existing regional defects:

[0306] P 总 = P 12 + P 21e

[0307] 2,1 The molar percentage of defects in the reddish region was quantified relative to all propylene:

[0308]

[0309] For copolymers, characteristic signals corresponding to ethylene incorporation were observed (Cheng, HN, Macromolecules 17 (1984), 1950).

[0310] Since regional defects have also been observed (Resconi, L., Cavallo, L., Fait, A., Piemontesi, F., Chem. Rev. 2000, 100, 1253; Wang, WJ., Zhu, S., Macromolecules 33 (2000), 1157; Cheng, HN, Macromolecules 17 (1984), 1950), it is necessary to correct for the effect of such defects on the comonomer content.

[0311] The comonomer fraction was determined using the method of Wang et al. (Wang, WJ., Zhu, S., Macromolecules 33 (2000), 1157), by analyzing... 13 C{ 1 Quantification is achieved by integrating multiple signals across the entire spectral region of the H spectrum. This method was chosen because of its robustness and ability to account for regional defects when necessary. The integration region was slightly adjusted to increase applicability across the entire range of comonomer contents encountered.

[0312] For systems where only isolated ethylene is observed in the PPEPP sequence, the method of Wang et al. was modified to reduce the influence of non-zero integrals from sites known to be absent. This method reduces the overestimation of ethylene content in such systems by reducing the number of sites used to determine absolute ethylene content to:

[0313]

[0314] By using this set of sites, the corresponding integral equation becomes:

[0315]

[0316] The same notation used is employed in the article by Wang et al. (Wang, WJ., Zhu, S., Macromolecules 33 (2000), 1157). The equation for absolute propylene content remains unchanged.

[0317] The molar percentage of comonomers incorporated is calculated from the mole fraction:

[0318]

[0319] The weight percentage of comonomers incorporated is calculated as a mole fraction:

[0320]

[0321] The distribution of comonomer sequences at the ternary group level was determined using the analytical method of Kakugo et al. (Kakugo, M., Naito, Y., Mizunuma, K., Miyatake, T. Macromolecules 15 (1982) 1150). This method was chosen because of its robustness and because the integration region was slightly adjusted to increase applicability to a wider range of comonomer contents.

[0322] Crystallization extraction (CRYSTEX)

[0323] Determination of crystalline and soluble fractions and their respective properties (IV and ethylene content)

[0324] The crystalline fraction (CF) and soluble fraction (SF) of polypropylene compositions, as well as the comonomer content and intrinsic viscosity of each fraction, were analyzed using a CRYSTEX instrument from Polymer Char (Valencia, Spain). Detailed information on this technique and method can be found in the literature (Ljiljana Jeremic, Andreas Albrecht, Martina Sandholzer & Markus Gahleitner (2020) Rapid characterization of high-impact ethylene–propylene copolymer composition by crystallization extraction separation: comparability to standard separation methods, International Journal of Polymer Analysis and Characterization, 25:8, 581-596).

[0325] Crystalline and amorphous fractions were separated by a temperature cycle of dissolution in 1,2,4-trichlorobenzene at 160°C, crystallization at 40°C, and redissolution at 160°C. Quantification of SF and CF, as well as determination of ethylene content (C2), were achieved using an integrated infrared detector (IR4), and intrinsic viscosity (iV) was determined using an online dual-capillary viscometer.

[0326] The IR4 detector is a multi-wavelength detector that measures two different wavelengths (CH3 stretching vibration, centered at approximately 2960 cm⁻¹). -1 (at the location) and CH stretching vibration (2700-3000cm) -1 The infrared absorbance of the IR4 detector is used to determine the concentration and ethylene content of ethylene-propylene copolymers. The IR4 detector is calibrated using a series of eight EP copolymers with known ethylene contents, ranging from 2% to 69% by weight. 13 (C-NMR determination), the concentrations of each copolymer varied, ranging from 2 to 13 mg / ml. To simultaneously obtain two characteristics (concentration and ethylene content) for the expected polymer concentrations during Crystex analysis, the following calibration equation was applied:

[0327] (Equation 1)

[0328] (Equation 2)

[0329] The constants a to e in equation 1 and the constants a to f in equation 2 were determined using least squares regression analysis.

[0330] Use the following relationship to convert CH3 / 1000C to ethylene content in weight percent:

[0331] (Equation 3)

[0332] The amounts of the soluble fraction (SF) and crystalline fraction (CF) were correlated, respectively, with the amounts of the "xylene cold soluble" (XCS) and xylene cold insoluble (XCI) fractions determined according to the ISO 16152 standard gravimetric method via XS calibration. XS calibration was achieved by testing various EP copolymers with XS contents ranging from 2-31 wt%. The determined XS calibration was linear.

[0333] (Equation 4)

[0334] The intrinsic viscosity (iV) of the parent EP copolymer and its soluble and crystalline fractions was determined using an online dual-capillary viscometer and correlated with the corresponding iV determined by the standard method in naphthalene according to ISO 1628-3. Calibration was performed using various EP / PP copolymers with iV = 2-4 dL / g. The determined calibration curves were linear.

[0335] (Equation 5)

[0336] The samples to be analyzed were weighed at concentrations ranging from 10 mg / ml to 20 mg / ml. To avoid injecting possible gels and / or polymers (e.g., PET and PA) that are insoluble in TCB at 160°C, the weighed samples were placed in a stainless steel mesh with a MW 0.077 / D 0.05 mm diameter.

[0337] After automatically injecting 1,2,4-TCB containing 250 mg / L of 2,6-di-tert-butyl-4-cresol (BHT) as an antioxidant into the sample vial, the sample is dissolved at 160°C with constant stirring at 400 rpm until completely dissolved, typically over 60 minutes. To prevent sample degradation, the polymer solution is covered under a nitrogen atmosphere during the dissolution process.

[0338] A specified volume of sample solution is injected into a column packed with an inert support, where sample crystallization and separation of the soluble and crystalline fractions occur. This process is repeated twice. During the first injection, the entire sample is measured at high temperature, and the iV [dl / g] and C2 [wt%] of the PP composition are determined. During the second injection, the soluble fraction (at low temperature) and the crystalline fraction (at high temperature) are measured under crystallization cycles (wt% SF, wt% C2, iV).

[0339] Intrinsic viscosity

[0340] The intrinsic viscosity was measured according to DIN ISO 1628 / 1, October 1999 (at 135°C, in naphthalene).

[0341] Density: ISO 1183, measured on a molded plate.

[0342] DSC analysis, melting temperature (T) m ) and heat of fusion (H f ), crystallization temperature (T) c ) and heat of crystallization (H c )

[0343] Measurements were taken on samples ranging from 5 to 7 mg using a TA Instrument Q200 differential scanning calorimeter (DSC). The DSC was operated according to ISO 11357 / Part 3 / Method C2, employing a heating / cooling / heating cycle at a scan rate of 10°C / min, covering a temperature range of -30 to +225°C. Crystallization temperature (T...) c ) and enthalpy of crystallization (H c The melting temperature (T) is determined from the cooling step. m ) and enthalpy of fusion (H m This is determined from the second heating step.

[0344] Xylene cold solubles (XCS, wt%): The content of xylene cold solubles (XCS) was determined at 25°C according to ISO 16152 (first edition; 2005-07-01).

[0345] Charpy notched impact strength according to ISO 179-1 / 1eA at 23°C using injection-molded specimens (80×10×4mm) prepared according to EN ISO 1873-2. 3 ) Measurement.

[0346] Tensile properties were determined on 4 mm thick injection-molded dumbbell-shaped specimens prepared according to EN ISO 1873-2. Tensile modulus was determined according to ISO 527-1A at a strain rate of 1 mm / min and at 23°C, 80°C, and 120°C, and yield stress was determined at a strain rate of 50 mm / min and at 23°C, 80°C, and 120°C.

[0347] The flexural modulus was determined on 80 mm × 10 mm × 4 mm specimens according to ISO 178 Method A (three-point bending test). According to the standard, a test speed of 2 mm / min and a span length 16 times the thickness were used. The test temperature was 23 ± 2 °C. Injection molding was carried out according to ISO 19069-2, and all materials were used with a melt temperature of 230 °C regardless of the melt flow rate of the material.

[0348] The ash content was measured according to the ISO 3451-1 (1997) standard.

[0349] Limonene detection

[0350] Estimation of limonene

[0351] The determination of benzene and limonene was based on the static headspace (HS) method. This analysis combines an HS injector with a gas chromatograph (GC) and a mass spectrometer (MS) for screening purposes.

[0352] Samples were transported to the laboratory in sealed aluminum-coated polyethylene (PE) bags. Before analysis, the samples were cryogenically ground, and a 2.000 ± 0.100 g portion was weighed into a 20 ml HS vial and tightly capped. Duplicate determinations were performed for each sample.

[0353] HS / GC / MS parameters

[0354]

[0355]

[0356] In this study, the statement "below the detection limit (<LOD)" describes the following situation: the matching factor is below 80 (AMDIS) or the signal-to-noise ratio of the peak in the sample run (Pk-pk S / N = corrected signal / Pk-pk noise, MSD ChemStation signal-to-noise ratio report) is below 3. The results refer only to the measured sample, the measurement time, and the applied parameters.

[0357] Standard solution

[0358] For positive identification and comparison with the (lowest) odor detection threshold (ODT), limonene standards were used.

[0359] For HS / GC / MS analysis, 5 µl of the corresponding standard was injected into a 20 ml HS vial, tightly capped, and measured.

[0360] Assuming complete evaporation of the standard substance, the concentration of limonene in the HS was estimated as listed in the following table.

[0361] Table: Calibration standards and ODT

[0362]

[0363] Data evaluation

[0364] Concentration of analyte in HS By considering the amount of substance and available HS volume Calculate (Equation 1).

[0365] (Equation 1)

[0366] To estimate the concentration of the analyte in the HS above the polymer sample, a single-point calibrated response factor is required. Rf (Equation 2). The peak area of ​​the analyte is obtained by integrating the extracted ion chromatogram (EIC). The corresponding target ions are listed in the table above.

[0367] (Equation 2)

[0368] Concentration of analyte in HS above polymer sample It is calculated by multiplying the response factor by the EIC peak area of ​​the sample (Equation 3).

[0369] (Equation 3)

[0370] Furthermore, the odor correlation of the analytes in the HS above the polymer sample was estimated using odor activity values ​​(OAV). Therefore, the concentration of the analytes in the HS above the polymer sample was... Compare with the (lowest) odor detection threshold (ODT) found in the literature (Equation 4) [1]. A value greater than 1 indicates that the analyte is correlated with odor at a given HS temperature.

[0371] (Equation 4)

[0372] Factors to consider and limitations

[0373] It must be considered that the ODT of some substances is below the detection limit (LOD) of this method. Therefore, components below the LOD may be missed, even though they are still relevant to the overall odor.

[0374] OAV is based on the assumption that HS parameters are correlated to some extent with the measurement conditions of ODT. Of course, this is not entirely applicable, as a 100°C temperature setting is not necessarily chosen for such experiments, thus limiting its practical value. Nevertheless, this method can at least indicate the odor correlation of defined labeled substances.

[0375] Given all the assumptions and limitations mentioned, the concentrations and odor activity values ​​of HS measured above the sample should only be considered as rough estimates.

[0376] References

[0377] [1] Van Gemert LJ, Odour Thresholds: Compilations of odourthreshold values ​​in air, water and other media, Utrecht, Oliemans Punter &Partners BV, 2011.

[0378] Branching index g'

[0379] Relative branching amount is determined using the g'-index of the branched polymer sample. The long-chain branching (LCB) index is defined as follows: It is well known that increasing the g' value decreases the branching content. [η] is the intrinsic viscosity of a polymer sample of a specific molecular weight in a TCB at 160°C, measured using an online viscosity detector and a concentration detector. The intrinsic viscosity was measured using the Solomon-Gatesman equation as described in the Cirrus Multi-Offline SEC-Software version 3.2 manual.

[0380] The required concentration for each elution slice was determined by an RI detector.

[0381] It is the intrinsic viscosity of a linear sample. This is the viscosity of branched samples with the same molecular weight and chemical composition. Number-average (g') n and weight g' w Defined as:

[0382]

[0383] Where a i It is the dW / dlogM of the series i, A i It is the cumulative dW / dlogM of the polymer up to fraction i. The linear reference (linear isotactic PP) varies with molecular weight. Measured using an online viscosity detector. The following K and α values ​​were obtained from linear references with a molecular weight range of logM = 4.5–6.1 ( (α = 0.681). The molecular weight of each slice used for g' calculation. Calculated using the following relationship: [η] for each specific sample br,iMeasured using an online viscosity and concentration detector.

[0384] gpcBR index:

[0385] The gpcBR index is calculated using the following formula:

[0386]

[0387] Mw (LS15) is calculated based on the elution area of ​​light scattering at a 15° angle, and [η] (bulk) (bulk) is calculated based on the elution area of ​​the corresponding viscosity detector. Both are calculated using Cirrus Multi-Offline SEC-Software version 3.2 and the following methods.

[0388]

[0389] Where K LS It is the light scattering constant at a 15° angle, dn / dc is the refractive index increment calculated based on the detector constant of the RI detector, and K IV It is the detector constant of the viscometer, Sp i C is the specific viscosity of each chromatographic slice, and C is the corresponding concentration, in g / dl.

[0390] F 30 Melt strength and v 30 Melt elongation

[0391] The tests described in this paper follow ISO 16790:2005. Strain hardening behavior was determined using the method described in the article “Rheotens-Mastercurves and Drawability of Polymer Melts, MH Wagner, Polymer Engineering and Science, Vol. 36, pp. 925-935”. The strain hardening behavior of the polymer was analyzed using a Rheotens apparatus (Göttfert GmbH, Germany, 74711 Clothmark, Siemens Street 2), in which a melt strip is stretched downwards by a set acceleration.

[0392] Rheotens experiments simulate industrial spinning and extrusion processes. In principle, the melt is extruded or forced through a circular die, and the resulting strip is drawn down. The stress on the extrudate is recorded as a function of melt properties and measured parameters (particularly the ratio of yield to draw speed, which is essentially a measure of extension rate). For the results presented below, the material was extruded using a HAAKE Polylab system laboratory extruder and a gear pump with a cylindrical die (L / D = 6.0 / 2.0 mm). To measure F... 30 Melt strength and v 30 Melt elongation, by bypassing a portion of the extruded polymer, sets the pressure at the extruder outlet (= gear pump inlet) to 30 bar.

[0393] The gear pump was pre-adjusted to a sliver extrusion speed of 5 mm / s, and the melt temperature was set to 200°C. The spinning length between the die and the Rheotens wheel was 80 mm. At the start of the experiment, the take-up speed of the Rheotens wheel was adjusted to the speed at which the polymer sliver was extruded (with zero tensile force). The experiment was then initiated by slowly increasing the take-up speed of the Rheotens wheel until the polymer filament broke. The wheel acceleration was sufficiently small to allow for measurement of tensile force under quasi-steady-state conditions. The acceleration of the downwardly stretched melt sliver was 120 mm / s. 2 Rheotens operates in conjunction with the PC program EXTENS. This is a real-time data acquisition program used to display and store measurement data of tensile force and pull-down speed. The endpoint of the Rheotens curve (force relative to wheel speed), i.e., the point where the polymer strip breaks, is taken as F. 30 Melt strength and v 30 The value of melt elongation.

[0394] The UL 94 vertical burning test was performed according to UL 94:2016. Samples were injection molded into strips 125±5 mm long, 13.0±0.5 mm wide, and 0.8 to 3.2 mm thick (1.5 mm thickness was used in the Examples section). Under Condition 1, samples were conditioned for 48 hours at a constant room temperature of 23±2°C and 50±10% humidity. Under Condition 2, samples were conditioned for 168 hours in a forced-air oven at 70±1°C, and then cooled in a desiccator at room temperature for at least 4 hours before testing. The test must be performed within 30 minutes of removing the sample from its conditioning environment. The sample was suspended vertically in the test chamber, and a first ignition was performed for 10 seconds, followed by a second ignition for another 10 seconds. The burning time after each ignition was recorded, along with any afterglow, burning drips from the cotton at the bottom of the test chamber, and whether the flame or afterglow spread to the fixture. The grade was V-0, V-1, V-2, or no grade, depending on the thickness of the test object.

[0395] B. Experiment

[0396] Polypropylene blends (PPB)

[0397] Table 1 shows the properties of the two polypropylene / polyethylene blends (PPB-1 and PPB-2) used for evaluation. Since these compositions are derived from a mechanical recycling process, the properties are expressed as a range.

[0398] Table 1: Properties of Polypropylene / Polyethylene Blends (Blends PPB-1 and PPB-2)

[0399]

[0400] Propylene polymer (PP)

[0401] Catalyst preparation

[0402] The catalyst used to produce the multiphase propylene copolymer HECO1 is the commercially available Ziegler-Natta catalyst from Lyondell Basell (Italy), traded as ZN180M.

[0403] The catalyst used to prepare the multiphase propylene copolymer HECO2 was prepared as follows:

[0404] 3.4 L of 2-ethylhexanol and 810 mL of propylene glycol butyl monoether (molar ratio 4 / 1) were added to a 20 L reactor. Then, 7.8 L of a 20% BEM (butylethyl magnesium) toluene solution (provided by Crompton GmbH) was slowly added to the well-stirred alcohol mixture. The temperature was maintained at 10°C during the addition. After addition, the temperature of the reaction mixture was raised to 60°C and mixing continued at this temperature for 30 minutes. Finally, after cooling to room temperature, the obtained magnesium alkoxide was transferred to a storage container. 21.2 g of the magnesium alkoxide prepared above was mixed with 4.0 mL of bis(2-ethylhexyl) citrate for 5 minutes. After mixing, the resulting magnesium complex was immediately used to prepare the catalyst component. 19.5 mL of titanium tetrachloride was placed in a 300 mL reactor equipped with a mechanical stirrer at 25°C. The stirring speed was adjusted to 170 rpm. 26.0 g of the magnesium complex prepared above was added over 30 minutes, maintaining the temperature at 25°C. Add 3.0 mL of Viscoplex 1-254 and 1.0 mL of toluene solution containing 2 mg Necadd 447. Then add 24.0 mL of heptane to form an emulsion. Continue mixing at 25°C for 30 minutes. Then raise the reactor temperature to 90°C over 30 minutes. Stir the reaction mixture at 90°C for another 30 minutes. Then stop stirring and allow the reaction mixture to stand at 90°C for 15 minutes.

[0405] The solid material was washed five times: washing was carried out at 80°C with stirring for 30 minutes at 170 rpm. After stopping stirring, the reaction mixture was allowed to stand for 20-30 minutes, followed by siphoning.

[0406] Wash 1: Wash with a mixture of 100 ml toluene and 1 ml electron donor.

[0407] Washing 2: Wash with a mixture of 30 ml TiCl4 and 1 ml electron donor.

[0408] Washing 3: Wash with 100 mL of toluene.

[0409] Washing 4: Wash with 60 mL of heptane.

[0410] Washing 5: Wash with 60 mL of heptane while stirring for 10 minutes.

[0411] Then stop stirring, let the reaction mixture stand for 10 minutes, and let the temperature drop to 70°C. Then siphon it and then purge with N2 for 20 minutes to produce an air-sensitive powder.

[0412] VCH modification of catalysts

[0413] Under room temperature and inert conditions, 35 mL of mineral oil (Paraffinum Liquidum PL68) was added to a 125 mL stainless steel reactor, followed by 0.82 g of triethylaluminum (TEAL) and 0.33 g of dicyclopentyldimethoxysilane (electron donor D). After 10 minutes, 5.0 g of the catalyst prepared in step 1a (Ti content 1.4 wt%) was added, followed by 5.0 g of vinylcyclohexane (VCH) after another 20 minutes. The temperature was raised to 60°C within 30 minutes and maintained for 20 hours. Finally, the temperature was lowered to 20°C, and the concentration of unreacted VCH in the oil / catalyst mixture was analyzed and found to be 120 ppm (by weight).

[0414] Polymerization of HECO1 and HECO2

[0415] HECO1 and HECO2 are produced in a configuration of prepolymerization / loop reactor / gas phase reactor 1 / gas phase reactor 2, followed by a granulation step.

[0416] For HECO1, the first catalyst system described above is used, combined with triethylaluminum (TEAL) as a co-catalyst and dicyclopentadienyldimethoxysilane (electron donor D) as an external electron donor.

[0417] For HECO2, the second catalyst system described above is used.

[0418] The preparation processes of the two propylene polymers (PP) (both multiphase propylene copolymers, HECO1 and HECO2) are summarized in Table 2.

[0419] Table 2: Polymerization conditions of HECO1 and HECO2

[0420]

[0421] Multiphase copolymers HECO1 and HECO2 were compounded in a Coperion ZSK 47 co-rotating twin-screw extruder at 220°C, with the addition of 0.15% by weight of antioxidant (Irganox B215FF from BASF AG, Germany; a 1:2 mixture of pentaerythritol tetra(3-(3',5'-di-tert-butyl-4-hydroxyphenyl)propionate) (CAS No. 6683-19-8) and tris(2,4-di-tert-butylphenyl) phosphite (CAS No. 31570-04-4)) and 0.05% by weight of calcium stearate (CAS No. 1592-23-0, purchased from Faci, Italy).

[0422] Preparation of polypropylene composition (C)

[0423] The components were melt-blended in a co-rotating twin-screw extruder in the amounts shown in Table 3.

[0424] Table 3: Composition and Performance of Comparative Examples and Inventions

[0425]

[0426] nd means undetermined

[0427] •FR is SULI’s commercial flame retardant composition Phlamoon-1090A, which contains 55 to 60% by weight melamine polyphosphate and 40 to 55% by weight piperazine pyrophosphate.

[0428] HMS-PP is Borealis' commercial long-chain branched polypropylene WB140HMS, with a melt flow rate (MFR2, 230°C, 2.16 kg) of 2.1 g / 10 min. 30 The melt strength is 36 cN, v 30 The melt elongation is 230 mm / s.

[0429] • The PTFE is commercially available PTFEDYNEONTF2025ZPTFE (3M).

[0430] CB1 is a commercial carbon black masterbatch CBMB-LD-09-A02 (containing 40% carbon black in LDPE).

[0431] • HDPE is Borealis AG's commercial high-density polyethylene MB7541, with an MFR (190°C / 2.16kg, ISO1133) of 4g / 10min and a density (ISO 1183) of 954kg / m³.

[0432] AO1 is the antioxidant 2,2'-oxalamide bis-(ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), which is commercially available as Addivant's Naugard XL-1.

[0433] AO2 is the antioxidant tris(2,4-di-tert-butylphenyl) phosphite, which is commercially available as BASF's Irgafos168.

[0434] AO3 is the antioxidant pentaerythritol tetrakis(3-(3',5'-di-tert-butyl-4-hydroxyphenyl)propionate), which is commercially available as BASF's Irganox 1010.

[0435] The flame retardancy and mechanical properties of the comparative and inventive compositions are summarized in Table 4.

[0436] Table 4: Performance of Comparative Examples and Invention Examples

[0437]

[0438] The UL94 vertical burning test was conducted under the conditions described in Section 1 of “Measurement Method - UL94 Vertical Burning Test” above, i.e., the sample was conditioned for 48 hours at a constant room temperature of 23±2°C and a humidity of 50±10%.

[0439] The UL94 vertical burning test was conducted under conditions 2 as described in Section 2 of “Measurement Methods - UL94 Vertical Burning Test” above, i.e., the sample was conditioned in a forced-air oven at 70±1°C for 168 hours and then cooled in a desiccator at room temperature for at least 4 hours.

[0440] nd = Undetermined

[0441] The inventive examples containing the mixed plastic polypropylene blends PPB-1 and PPB-2 surprisingly exhibit performance comparable to that of Reference Example RE1, which contains only the native multiphase propylene copolymer HECO as a propylene polymer.

[0442] Comparative Example CE1, containing 36.8 wt% of a blend of polypropylene PPB-1 and 36.8 wt% of HECO2, failed the UL94 vertical burning test under Condition 1. Comparative Example CE2, containing 14.8 wt% of a blend of polypropylene PPB-2 and 58.9 wt% of HECO2, failed the UL94 vertical burning test under both Condition 1 and Condition 2. Therefore, these compositions are not suitable as flame-retardant materials for electronic enclosures.

Claims

1. A polypropylene composition (C), wherein, The polypropylene composition (C) comprises: i) 30.0 to 90.0% by weight of mixed plastic polypropylene blends (PPB); ii) 10.0 to 40.0% by weight of flame retardant (FR). iii) 0.01 to 30.0% by weight of anti-dripping agent (AD), and iv) 0 to 25.0% by weight of a propylene polymer (PP), wherein the propylene polymer (PP) has a melt flow rate MFR2 (230°C, 2.16 kg) of at least 15.0 g / 10 min as determined according to ISO 1133. All weight percentages are based on the total weight of the polypropylene composition (C).

2. The polypropylene composition (C) according to claim 1, wherein, The polypropylene composition (C) has one or more of the following properties: • In the UL94 flame retardancy test after 48 hours of conditioning according to condition section 1, the UL94 rating is V-0; • In the UL94 flame retardancy test after 168 hours of conditioning according to condition section 2, the UL94 rating was V-0. The UL94 flame retardancy test was conducted on injection-molded samples with a length of 125±5 mm, a width of 13.0±0.5 mm, and a thickness of 1.5 mm.

3. The polypropylene composition (C) according to claim 1 or 2, wherein, The polypropylene composition (C) has one or more of the following properties: • The tensile modulus, as determined by ISO 527-1A at 23°C, is at least 1250 MPa, for example 1250 to 3000 MPa, preferably 1500 to 2500 MPa, and more preferably 1650 to 2250 MPa. • The tensile strength measured at 23°C according to ISO 527-1A is at least 12 MPa, for example 12 to 40 MPa, preferably 15 to 35 MPa, more preferably 17 to 30 MPa; • The tensile stress at break, as determined by ISO 527-1A at 23°C, is at least 2.3%, for example, from 2.3 to 7.5%, preferably from 2.5 to 7.0%, and more preferably from 2.7 to 6.0%.

4. The polypropylene composition (C) according to any one of claims 1 to 3, wherein, The polypropylene composition (C) has one or more of the following properties: • The Charpy notched impact strength at 23°C, as determined by ISO 179-1 / 1eA, is at least 1.0 kJ / m. 2 For example, 1.0 to 10.0 kJ / m 2 The preferred concentration is 1.2 to 8.5 kJ / m³. 2 More preferably 1.5 to 7.5 kJ / m 2 ; • The melt flow rate (MFR2) measured according to ISO 1133 at 2.16 kg and 230°C is 2.5 to 20.0 g / 10 min, preferably 3.0 to 15.0 g / 10 min, and more preferably 4.0 to 12.5 g / 10 min.

5. The polypropylene composition (C) according to any one of claims 1 to 4, wherein, The mixed plastic polypropylene blend (PPB) has the following characteristics: • The content of the crystal fraction (CF), as determined by CRYSTEX QC analysis, is in the range of 80.0 to 96.0% by weight, preferably in the range of 82.5 to 95.5% by weight. • The soluble fraction (SF) content, as determined by CRYSTEX QC analysis, is in the range of 4.0 to 20.0% by weight, preferably in the range of 4.5 to 17.5% by weight. • The crystalline fraction (CF) is obtained through quantitative analysis. 13 The ethylene content (C2(CF)) determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy is in the range of 1.0 to 15.0% by weight, preferably in the range of 1.5 to 12.5% ​​by weight; • The intrinsic viscosity (iV(CF)) of the crystalline fraction (CF) is in the range of 0.9 to 2.1 dl / g, preferably in the range of 1.0 to 2.0 dl / g, and more preferably in the range of 1.1 to 1.9 dl / g; • The soluble fraction (SF) is obtained through quantitative analysis. 13 The ethylene content (C2(SF)) determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy is in the range of 15.0 to 40.0% by weight, preferably in the range of 20.0 to 37.5% by weight; and • The intrinsic viscosity (iV(SF)) of the soluble fraction (SF) is in the range of 0.9 to 2.2 dl / g, preferably in the range of 1.0 to 2.1 dl / g, and more preferably in the range of 1.1 to 2.0 dl / g.

6. The polypropylene composition (C) according to any one of claims 1 to 5, wherein, The mixed plastic polypropylene blend (PPB) has one or more of the following properties: • The melt flow rate MFR2, as determined according to ISO 1133 at 2.16 kg and 230°C, is 15.0 to 40.0 g / 10 min, preferably 16.5 to 35.0 g / 10 min, and more preferably 17.5 to 30.0 g / 10 min; • The density, as determined by ISO 1183, is 900 to 1030 kg / m³. 3 Preferably, it is 905 to 1020 kg / m³ 3 More preferably 910 to 1010 kg / m 3 ; • The limonene content, determined using solid-phase microextraction (HS-SPME-GC-MS), ranged from 1 to 250 mg / m³. 3 ; • The tensile modulus, as determined according to ISO 527-2, is from 1000 MPa to 1750 MPa, preferably from 1100 MPa to 1600 MPa; • The Charpy notched impact strength at 23°C, as determined by ISO 179-1 / 1eA, is 3.0 to 7.5 kJ / m. 2 Preferably, it is 4.0 to 7.0 kJ / m 2 .

7. The polypropylene composition (C) according to any one of claims 1 to 6, wherein, The flame retardant (FR) is a nitrogen-containing flame retardant (FR); more preferably, the flame retardant (FR) comprises a first nitrogen-containing phosphate (FR1) and a second nitrogen-containing phosphate (FR2), optionally, the weight ratio between the first nitrogen-containing phosphate (FR1) and the second nitrogen-containing phosphate (FR2) is in the range of 60:40 to 40:60, wherein the first nitrogen-containing phosphate (FR1) is preferably melamine polyphosphate, and the second nitrogen-containing phosphate (FR2) is preferably piperazine pyrophosphate.

8. The polypropylene composition (C) according to any one of claims 1 to 7, wherein, The flame retardant (FR) is halogen-free.

9. The polypropylene composition (C) according to any one of claims 1 to 8, wherein, The polypropylene composition (C) comprises: i) 55.0 to 90.0% by weight, preferably 62.5 to 84.0% by weight, more preferably 66.5 to 79.0% by weight of mixed plastic polypropylene blends (PPB); ii) 10.0 to 40.0% by weight, 15.0 to 35.0% by weight, more preferably 20.0 to 32.5% by weight of flame retardant (FR); iii) 0.01 to 5.0% by weight, preferably 0.05 to 2.5% by weight, more preferably 0.1 to 1.5% by weight of an anti-dripping agent, wherein the anti-dripping agent is a halogenated polyolefin, preferably a fluorinated polyolefin, and most preferably polytetrafluoroethylene (PFTE). iv) 0% by weight of propylene polymer (PP), said propylene polymer (PP) having a melt flow rate MFR2 (230°C, 2.16 kg) of at least 15.0 g / 10 min as determined according to ISO 1133, and v) 0 to 15.0% by weight, preferably 0 to 12.5% ​​by weight, more preferably 0 to 10.0% by weight of additives (ADD). All weight percentages are based on the total weight of the polypropylene composition (C).

10. The polypropylene composition (C) according to any one of claims 1 to 8, wherein, The polypropylene composition (C) comprises: i) 30.0 to 80.0% by weight, preferably 35.0 to 70.0% by weight, more preferably 40.0 to 60.0% by weight of mixed plastic polypropylene blend (PPB). ii) 10.0 to 40.0% by weight, 15.0 to 35.0% by weight, more preferably 20.0 to 32.5% by weight of flame retardant (FR). iii) 10.0 to 30.0% by weight, preferably 12.5 to 27.5% by weight, more preferably 15.0 to 25.0% by weight of an anti-dripping agent, wherein the anti-dripping agent is high melt strength polypropylene (HMS-PP). iv) 0% by weight of a propylene polymer (PP), wherein the propylene polymer (PP) has a melt flow rate MFR2 (230°C, 2.16 kg) of at least 15.0 g / 10 min as determined according to ISO 1133; and v) 0 to 15.0% by weight, preferably 0 to 12.5% ​​by weight, more preferably 0 to 10.0% by weight of additives (ADD). All weight percentages are based on the total weight of the polypropylene composition (C).

11. The polypropylene composition (C) according to any one of claims 1 to 8, wherein, The polypropylene composition (C) comprises: i) 30.0 to 69.0% by weight, preferably 35.0 to 60.0% by weight, more preferably 40.0 to 50.0% by weight of mixed plastic polypropylene blend (PPB). ii) 10.0 to 40.0% by weight, 15.0 to 35.0% by weight, more preferably 20.0 to 32.5% by weight of flame retardant (FR). iii) 10.0 to 30.0% by weight, preferably 12.5 to 27.5% by weight, more preferably 15.0 to 25.0% by weight of an anti-dripping agent, wherein the anti-dripping agent is high melt strength polypropylene (HMS-PP). iv) 11.0 to 25.0% by weight, preferably 12.5 to 22.5% by weight, more preferably 15.0 to 20.0% by weight of a propylene polymer (PP), wherein the propylene polymer (PP) has a melt flow rate MFR2 (230°C, 2.16 kg) of at least 15.0 g / 10 min as determined according to ISO 1133; and v) 0 to 15.0% by weight, preferably 0 to 12.5% ​​by weight, more preferably 0 to 10.0% by weight of additives (ADD). All weight percentages are based on the total weight of the polypropylene composition (C).

12. The polypropylene composition (C) according to claim 10 or 11, wherein, The polypropylene composition (C) contains no more than 0.5% by weight of fluoropolymer, more preferably no more than 0.1% by weight, even more preferably no more than 0.01% by weight, for example no more than 0.001% by weight, and most preferably no fluoropolymer.

13. The polypropylene composition (C) according to any one of claims 1 to 12, wherein, The propylene polymer (PP) is a multiphase propylene copolymer (HECO), which has one or more of the following properties: • The melt flow rate MFR2 (230°C, 2.16 kg) as determined according to ISO 1133 is at least 45.0 g / 10 min, for example in the range of 45.0 to 300 g / 10 min, preferably in the range of 60.0 to 200 g / 10 min, and more preferably in the range of 80.0 to 120 g / 10 min; • Based on the total weight of the multiphase propylene copolymer (HECO), the xylene cold soluble fraction (XCS) ranges from 7.0 to 25.0% by weight; The xylene-soluble fraction (XCS) of the multiphase propylene copolymer (HECO) has the following characteristics: • Comonomer content higher than 35.0 mol.% and / or • Intrinsic viscosity (IV) below 3.5 dl / g as determined by ISO 1628 / 1 (at 135°C in naphthalene).

14. The polypropylene composition (C) according to any one of claims 1 to 13, wherein, The total amount of the mixed plastic polypropylene blend (PPB), the flame retardant (FR), the anti-dripping agent (AD), and the optional propylene polymer (PP) accounts for at least 85.0% by weight of the polypropylene composition (C).

15. An article comprising the polypropylene composition (C) according to any one of claims 1 to 14.

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