Flame-retardant polypropylene composition

Abstract

The present invention relates to a polypropylene composition (C) comprising a propylene homopolymer, a hybrid plastic polypropylene blend (PPB), a flame retardant (FR), fibers (F) and optionally an adhesion promoter (AP). The invention also relates to an article comprising said polypropylene composition (C).

Description

TECHNICAL FIELD

[0001] The present invention relates to a polypropylene composition comprising a mixed plastic polypropylene blend (PPB) and a flame retardant (FR). The present invention further relates to an article comprising the polypropylene composition. BACKGROUND

[0002] Motor and power electronics manufacturers have been using steel or die cast aluminum housings for a long time. However, as many components nowadays are actively cooled, a plastic solution offers the possibility to realize lightweight constructions. Some of the existing alternatives are mainly based on PC / ABS or polyamides, which are engineering plastics with high production costs and a high CO2 footprint.

[0003] Furthermore, one of the mandatory requirements for electronic housings is to reach a UL94 V-0 flame retardant rating at a thickness below 1.5 mm. Materials that fulfill these requirements are most likely metals, halogen-based flame retardant reinforced polymers, polymers with intrinsic flame retardancy or the use of non-halogen-based flame retardant reinforced polymers such as PC / ABS flame retardant systems. Due to the high loading of flame retardant additives in such flame retardant systems, material property degradation and conversion issues occur. Furthermore, anti-dripping agents are usually added to prevent dripping during the burning process.

[0004] Polypropylene polymers can also be used as base polymers for flame retardant systems. In general, glass fibers are used in combination with polypropylene to achieve specific mechanical properties (e.g. stiffness). However, the main drawback of glass fiber reinforced polypropylene is the dimensional stability of the fiber direction and the high warpage, especially when using high flow polypropylene as base polymer. However, low warpage is crucial for high precision parts such as battery holders and the like.

[0005] In recent years, polymer waste has been considered a major environmental and economic problem. Therefore, efforts have been made to recycle polymer waste and use the recycled polymers for upcycling applications. However, a decrease in mechanical properties is usually observed when virgin starting materials and recycled materials are mixed.

[0006] WO 2022 / 189647 A1 discloses a flame retardant reinforced high flow polypropylene composition made from virgin components, which fulfills the requirements of UL94 V-0 and exhibits low warpage while the mechanical properties remain at a high level.

[0007] Surprisingly, it was found that replacing up to 30 wt.-% of the virgin polypropylene polymer in the composition of WO 2022 / 189647 A1 with a mixed plastic polypropylene blend (PPB), preferably from post-consumer waste, did not observe the expected loss in mechanical properties and UL94 testing. Summary of the Invention

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

[0009] i) 5.0 to 40.0 wt.% of propylene homopolymer (PP-H), wherein the propylene homopolymer (PP-H) has a melt flow rate MFR2 (230°C, 2.16 kg) of at least 75.0 g / 10 min as determined according to ISO 1133;

[0010] ii) 5.0 to 20.5 wt.% of a mixed plastic polypropylene blend (PPB), wherein the mixed plastic polypropylene blend (PPB) 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;

[0011] iii) 10.0 to 40.0 wt.% flame retardant (FR);

[0012] iv) 10.0 to 40.0 wt.% of fiber (F); and

[0013] v) 0.0 to 5.0 wt.% of adhesion promoter (AP).

[0014] All weight percentages are based on the total weight of the polypropylene composition (C).

[0015] Furthermore, the present invention relates to an article comprising the polypropylene composition (C) described above or below.

[0016] definition

[0017] 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 the invention may be tested in practice using similar or equivalent methods and materials as described herein, preferred materials and methods are described herein. In describing and claiming protection for this invention, the following terms will be used according to the definitions below. Unless explicitly stated otherwise, the use of the terms "a," "an," and similar terms refers to more than one.

[0018] Blended plastics are defined as containing small amounts of compounds not normally present 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.

[0019] By definition, "mixed plastics" can be equivalent to detectable amounts of polystyrene and / or polyamide-6 and / or limonene and / or fatty acids.

[0020] Therefore, unlike virgin polymers, blended plastics can originate from post-consumer waste and industrial waste. Post-consumer waste refers to items that have completed at least their first use cycle (or life cycle), i.e., items that have achieved their first purpose. In contrast, industrial waste refers to manufacturing waste, or conversion waste, that does not typically reach consumers.

[0021] The term "raw" refers to newly produced materials and / or articles that have not yet been recycled and are before their first use.

[0022] The term “recycled material” as used in this article refers to materials that are reprocessed from “recycled waste”.

[0023] Polymer blends are mixtures of two or more polymer components. Typically, blends are prepared by mixing two or more polymer components. A suitable mixing process 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 process by melt mixing the polymer components.

[0024] Mixed plastic polypropylene blends refer to blends that mainly contain polypropylene, but also contain small amounts of other plastics.

[0025] A blend of polyethylene plastics refers to a blend that mainly contains polyethylene, but also contains small amounts of other plastics.

[0026] Recyclable blends, especially post-consumer recycled blends, are almost always mixed plastic blends, reflecting the efficiency of sorting in the most advanced recycling processes available.

[0027] Polypropylene refers to a polymer composed of more than 50 mol% units derived from propylene.

[0028] Polyethylene refers to a polymer composed of more than 50 mol% of units derived from ethylene.

[0029] Propylene homopolymers are polymers primarily composed of propylene monomer units. Due to impurities, especially those from commercial polymerization processes, polypropylene 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.

[0030] The presence of multiphase properties can be readily determined by the number of glass transition points in, for example, in dynamic mechanical analysis (DMA) and / or high-resolution microscopy (e.g., scanning electron microscopy (SEM), transmission electron microscopy (TEM), or atomic force microscopy (AFM)).

[0031] 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.

[0032] Reactor blends refer to blends produced in reactors with two or more reactors in series or reactors with two or more reaction chambers. Reactor blends can also be prepared by solution blending. Reactor blends are contrasted with compounds produced by melt extrusion.

[0033] Unless otherwise specified, "%" refers to weight - % (wt. - %). Detailed Implementation

[0034] This invention relates to a polypropylene composition (C) comprising:

[0035] i) 5.0 to 40.0 wt.-%, preferably 10.0 to 35.0 wt.-%, more preferably 20.0 to 30.0 wt.-%, of propylene homopolymer (PP-H), wherein the propylene homopolymer (PP-H) has a melt flow rate MFR2 (230°C, 2.16 kg) of at least 75.0 g / 10 min as determined according to ISO 1133;

[0036] ii) 5.0 to 20.5 wt.-%, preferably 10.0 to 20.3 wt.-%, more preferably 150 to 20.1 wt.-%, of a mixed plastic polypropylene blend (PPB) 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;

[0037] iii) 10.0 to 40.0 wt.-%, preferably 15.0 to 35.0 wt.-%, more preferably 20.0 to 32.5 wt.-% of flame retardant (FR);

[0038] iv) 10.0 to 40.0 wt.-%, preferably 12.0 to 38.0 wt.-%, more preferably 20.0 to 30.0 wt.-%, of fiber (F); and

[0039] v) 0.0 to 5.0 wt.-%, preferably 0.4 to 3.0 wt.-%, more preferably 1.0 to 2.0 wt.-% of adhesion promoter (AP).

[0040] All weight percentages are based on the total weight of the polypropylene composition (C).

[0041] Preferably, the total content of propylene homopolymer (PP-H), blended plastic polypropylene blend (PPB), flame retardant (FR), fiber (F), and optional adhesion promoter (AP) is at least 90 wt.- of the polypropylene composition (C).

[0042] The polypropylene composition (C) according to the present invention may further include additives (AD), such as acid scavengers, antioxidants, colorants, light stabilizers, slip agents, scratch resistant agents, dispersants, processing aids, lubricants, pigments, etc.

[0043] Therefore, preferably, the polypropylene composition (C) comprises the following components, more preferably, it consists of the following components:

[0044] i) 5.0 to 40.0 wt.-%, preferably 10.0 to 35.0 wt.-%, more preferably 20.0 to 30.0 wt.-%, of propylene homopolymer (PP-H), wherein the propylene homopolymer (PP-H) has a melt flow rate MFR2 (230°C, 2.16 kg) of at least 75.0 g / 10 min as determined according to ISO 1133;

[0045] ii) 5.0 to 20.5 wt.-%, preferably 10.0 to 20.3 wt.-%, more preferably 150 to 20.1 wt.-%, of a mixed plastic polypropylene blend (PPB) 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;

[0046] iii) 10.0 to 40.0 wt.-%, preferably 15.0 to 35.0 wt.-%, more preferably 20.0 to 32.5 wt.-% of flame retardant (FR);

[0047] iv) 10.0 to 40.0 wt.-%, preferably 12.0 to 38.0 wt.-%, more preferably 20.0 to 30.0 wt.-%, of fiber (F); and

[0048] v) 0.0 to 5.0 wt.-%, preferably 0.4 to 3.0 wt.-%, more preferably 1.0 to 2.0 wt.-% of an adhesion promoter (AP); and

[0049] vi) 0.01 to 5.0 wt.-%, preferably 0.1 to 3.5 wt.-%, more preferably 0.2 to 2.0 wt.-% of additives (AD).

[0050] All weight percentages are based on the total weight of the polypropylene composition (C). Additives (AD) will be described in more detail below.

[0051] Preferably, the total content of propylene homopolymer (PP-H), blended plastic polypropylene blend (PPB), flame retardant (FR), fiber (F), adhesion promoter (AP) and additive (AD) is at least 90 wt.- of the polypropylene composition (C), more preferably the total is 100 wt.-.

[0052] According to a preferred embodiment of the present invention, the polypropylene composition (C) is free of fluoropolymers. Specifically, preferably, the content of fluoropolymers in the polypropylene composition (C) is no more than 0.5 wt.-%, more preferably no more than 0.1 wt.-%, and even more preferably no more than 0.01 wt.-%, for example, 0.001 wt.-%. Particularly preferably, no fluoropolymers are used in the production process of the polypropylene composition (C).

[0053] As used herein, the term "fluoropolymer" refers to polymer compounds containing fluorine atoms. Examples of fluoropolymers include polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and polychlorotrifluoroethylene (PCTFE).

[0054] Preferably, the melt flow rate (MFR2) of the polypropylene composition (C) according to ISO 1133, measured at 2.16 kg and 230 °C, is 2.5 to 30.0 g / 10 min, more preferably 5.0 to 25.0 g / 10 min, and more preferably 10.0 to 22.5 g / 10 min.

[0055] For mechanical properties, preferably, the tensile modulus of the polypropylene composition (C) as determined according to ISO 527-1A at 23°C is at least 5500 MPa, for example, 5500 to 10000 MPa, more preferably 6000 to 9500 MPa, and more preferably 6250 to 9000 MPa.

[0056] Furthermore, preferably, the tensile strength of the polypropylene composition (C) as determined by ISO 527-1A at 23°C is at least 50 MPa, for example 50 to 100 MPa, more preferably 55 to 95 MPa, and more preferably 60 to 90 MPa.

[0057] Furthermore, preferably, the tensile stress at break of the polypropylene composition (C), as determined according to ISO 527-1A at 23°C, is at least 1.7%, for example, from 1.7% to 5.0%, more preferably from 2.0% to 4.5%, and more preferably from 2.2% to 4.0%.

[0058] As a supplement to or alternative to the preceding content, preferably, the polypropylene composition (C) has a Charpy notched impact strength of at least 6.5 kJ / m², as determined according to ISO 179-1eA at 23°C. 2 For example, 6.5 to 15.0 kJ / m 2 Preferably, it is 6.7 to 12.5 kJ / m 2 More preferably, it is 7.0 to 10.0 kJ / m 2 .

[0059] Preferably, when the test is performed using a 1.5 mm thick specimen and under the conditions described in Part 1 (i.e., the specimen is conditioned for 48 hours at a constant temperature of 23±2°C and 50±10% humidity) according to the “UL 94 Vertical Burning Test” method described in the “Measuring Methods” section of this document, the polypropylene composition (C) meets the requirements of the UL94 V-0 standard for the flammability safety of plastic materials.

[0060] Furthermore, when measured according to the “UL 94 Vertical Burning Test” method described in the “Measuring Methods” section of this document, using a specimen with a thickness of 1.5 mm and applying the conditions in Part 1 (i.e., conditioning the sample in an air-circulating oven at 70±1°C for 168 hours, and then cooling it in a desiccator at room temperature for at least 4 hours), the polypropylene composition (C) preferably meets the requirements of the UL 94 V-0 standard for the flammability safety of plastic materials.

[0061] Preferably, the polypropylene composition (C) is prepared by blending (preferably melt blending) propylene homopolymer (PP-H), blended plastic polypropylene blend (PPB), flame retardant (FR), glass fiber (GF), adhesion promoter (AP), and optional additives (AD).

[0062] The following sections will describe in more detail the propylene homopolymer (PP-H), blended polypropylene (PPB), flame retardant (FR), glass fiber (GF), and adhesion promoter (AP).

[0063] Propylene homopolymer (PP-H)

[0064] The polypropylene composition (C) contains propylene homopolymer (PP-H).

[0065] Propylene homopolymer (PP-H) can also be a mixture of two or more propylene homopolymer components. However, preferably, propylene homopolymer (PP-H) consists of a single propylene homopolymer component.

[0066] The melt flow rate (MFR2, 230°C, 2.16 kg) of the propylene homopolymer (PP-H) as determined according to ISO 1133 is at least 75.0 g / 10 min, for example, 75.0 to 750 g / 10 min, preferably 75.0 to 700 g / 10 min, and more preferably 100 to 650 g / 10 min.

[0067] In one specific embodiment, the melt flow rate MFR2 (230°C, 2.16 kg) of the propylene homopolymer (PP-H) as determined according to ISO 1133 is 105 to 600 g / 10 min, preferably 110 to 550 g / 10 min, more preferably 120 to 500 g / 10 min, even more preferably 200 to 500 g / 10 min, and most preferably 300 to 500 g / 10 min.

[0068] Preferably, the melting temperature Tm of the propylene homopolymer (PP-H) as determined by DSC is 155 to 170°C, more preferably 157 to 165°C.

[0069] Furthermore, the density of the propylene homopolymer (PP-H), as determined according to ISO 1183, is preferably 890 to 910 kg / m³. 3 More preferably, it is 895 to 905 kg / m 3 .

[0070] Preferably, the polydispersity index (i.e., the ratio of weight-average molecular weight to number-average molecular weight, Mw / Mn) of the propylene homopolymer (PP-H) as measured by GPC is less than 5.0, for example, from 1.5 to 4.5, and more preferably from 2.0 to 4.0.

[0071] Preferably, the propylene homopolymer (PP-H) has a flexural modulus of at least 1200 MPa, for example, from 1200 MPa to 1750 MPa, and more preferably from 1400 MPa to 1600 MPa, as determined by ISO 178 Method A.

[0072] Propylene homopolymer (PP-H) can be directly prepared in a polymerization reactor using known processes described in several patent applications (e.g., EP0320150, EP0480190, EP0622380, EP1303547, EP1538167, EP1783145, WO2007 / 140019, etc.). Alternatively, propylene homopolymer (PP-H) can also be obtained using controlled rheology (CR) techniques, including, for example, viscous cleavage, which refers to post-reactor treatment of polymers with low melt flow rates to induce controlled cleavage of polymer molecules in the molten state. Cleavage can be achieved through mechanical shearing, radiation, oxidation, or chemical methods (e.g., using peroxides). Preferably, controlled rheology treatment is performed using organic peroxides. The viscosity-reducing pyrolysis process for propylene polymer materials is well known to those skilled in the art and has been described in numerous patent applications (e.g., US3940379, US4951589, US4282076, US5250631, EP0462574, WO02 / 096986, WO2004 / 113438, etc.). The polymer used as the starting compound for controlled rheology treatment can be prepared by any polymerization process known in the art. This polymerization process can be continuous or batch, and can be carried out using known methods in the liquid phase (optionally in the presence of an inert diluent), in the gas phase, or via liquid-gas phase mixing techniques. The process is preferably carried out in the presence of a stereotactic catalyst system. The catalyst can be any conventional stereotactic Ziegler-Natta catalyst or any metallocene catalyst capable of catalyzing the formation of propylene polymers.

[0073] The propylene homopolymer (PP-H) is preferably the original polymer.

[0074] Propylene homopolymers suitable for use as propylene homopolymers (PP-H) are commercially available.

[0075] Before being mixed with other components to prepare the polypropylene composition (C), the propylene homopolymer (PP-H) may be ventilated (e.g., as described in EP3786190A1) to remove volatile components.

[0076] Mixed plastic polypropylene blend (PPB)

[0077] The polypropylene composition (C) comprises a blend of polypropylene polymers (PPB).

[0078] Polypropylene blends (PPB) are recycled materials rich in polypropylene, meaning they contain significantly more polypropylene than polyethylene. Polypropylene-rich recycling streams can be obtained from, for example, the automotive industry, especially since some automotive parts (such as bumpers) are sources of relatively pure polypropylene material in recycling streams.

[0079] 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 Reuse of Packaging Plastic Waste), Resource Plastics Corp. (Bampton, Ontario), Kruschitz GmbH, Plasticsand Recycling (Austria), Vogt Plastik GmbH (Germany), Mtm ​​Plastics GmbH (Germany), Borealis AG (Austria), etc. Non-exhaustive examples of polypropylene-rich recycled materials include: Purpolen ® PP (MtmPlastics GmbH) and Borcycle TM M (Borealis AG).

[0080] During recycling, any reasonable measures are typically taken (where the final application or use indicates the need for such measures) to reduce / remove any components other than polyethylene and polypropylene; however, other components are usually present in small amounts.

[0081] Other such components include polystyrene (PS), polyamide (PA), and polyethylene terephthalate (PET), which are present in the lowest possible amounts, preferably below the detection limit.

[0082] Preferably, the melt flow rate (MFR2) of the polypropylene blend (PPB) is 15.0 to 40 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, as determined by ISO 1133 at 230 °C and 2.16 kg.

[0083] Furthermore, the density of the polypropylene blend (PPB) as 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 .

[0084] Polypropylene blends (PPB) 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).

[0085] Preferably, the blended polypropylene (PPB) plastics exhibit one or more of the following properties in CRYSTEX QC analysis:

[0086] - The content of the crystal fraction (CF) as determined by CRYSTEX QC analysis is 80.0 to 96.0 wt.-%, preferably 82.5 to 95.5 wt.-%, more preferably 85.0 to 95.0 wt.-%; and

[0087] - The soluble fraction (SF) content, as determined by CRYSTEX QC analysis, is 4.0 to 20.0 wt.-, preferably 4.5 to 17.5 wt.-, and more preferably 5.0 to 15.0 wt.-.

[0088] The crystalline fraction (CF) preferably has one or more, preferably all of the following properties:

[0089] -Through quantitative 13 The ethylene content (C2(CF)) determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy is 1.0 to 15.0 wt.-%, preferably 1.5 to 12.5 wt.-%, more preferably 2.0 to 11.5 wt%; and / or

[0090] - The intrinsic viscosity (iV(CF)) of decahydronaphthalene, as determined according to DIN ISO 1628 / 1 at 135°C, is 0.9 to 2.1 dl / g, preferably 1.0 to 2.0 dl / g, and more preferably 1.1 to 1.9 dl / g.

[0091] Preferably, the soluble fraction (SF) has one or more, preferably all of, the following properties:

[0092] -Through quantitative 13 The ethylene content (C2(SF)) determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy is 15.0 to 40.0 wt.-%, preferably 20.0 to 37.5 wt.-%, more preferably 22.5 to 35.0 wt.-%; and / or

[0093] - The intrinsic viscosity (iV(SF)) of decahydronaphthalene, as determined according to DIN ISO 1628 / 1 at 135°C, is 0.9 to 2.2 dl / g, preferably 1.0 to 2.1 dl / g, and more preferably 1.1 to 2.0 dl / g.

[0094] Preferably, the mixed plastic polypropylene blend (PPB) contains 2.5 to 15.0 wt.-%, more preferably 3.0 to 13.5 wt.-%, and most preferably 3.5 to 12.5 wt.-% of ethylene-derived units.

[0095] Preferably, the inorganic residue content of the polypropylene blend (PPB) as determined by calcination analysis according to DIN ISO 1172:1996 is 0.05 to 3.0 wt.-, more preferably 0.5 to 2.5 wt.-, and most preferably 1.0 to 2.5 wt.-.

[0096] Preferably, the mixed plastic polypropylene blend (PPB) is derived from post-industrial or post-consumer waste, with post-consumer waste being the most preferred source.

[0097] The preferred limonene content of the polypropylene blend (PPB) determined by solid-phase microextraction (HS-SPME-GC-MS) is 1 to 250 mg / m³. 3 .

[0098] The presence of limonene indicates that the blended plastic polypropylene (PPB) is derived from post-consumer waste.

[0099] 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.

[0100] Therefore, it is also preferable 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.

[0101] CIELAB color space for blended polypropylene (PPB) plastics The preferred option is:

[0102] i) The value is 50.0 to 97.0, more preferably 80.0 to 97.0;

[0103] ii) The range is from -5.0 to 0.0;

[0104] iii) The range is from 0.0 to 22.0 (excluding 22.0).

[0105] Preferably, the tensile modulus of the mixed plastic polypropylene blend (PPB) is 1000 to 1750 MPa, more preferably 1100 to 1600 MPa, and even more preferably 1150 to 1500 MPa.

[0106] Furthermore, preferably, the Charpy notched impact strength (CNIS at 23°C) of the blended plastic polypropylene (PPB) is 3.0 to 7.5 kJ / m. 2 More preferably, it is 4.0 to 7.0 kJ / m 2 .

[0107] Before blending with other components to prepare a polypropylene composition (C), the blended plastic polypropylene blend (PPB) may be ventilated (e.g., as described in EP3786190A1) to remove volatile components.

[0108] Flame retardant (FR)

[0109] The polypropylene composition (C) contains a flame retardant (FR). The flame retardant (FR) may be a mixture of two or more flame retardants (FR).

[0110] The flame retardant product can be any flame retardant product suitable for polypropylene resins.

[0111] Preferably, the flame retardant (FR) is halogen-free. In other words, preferably, the flame retardant (FR) 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.

[0112] Preferably, the polypropylene composition (C) contains a nitrogen-containing flame retardant (FR).

[0113] 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.

[0114] 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), wherein the second nitrogen-containing phosphate (FR2) is different from the first nitrogen-containing phosphate (FR1).

[0115] 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.

[0116] 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.

[0117] 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.

[0118] According to a preferred embodiment of the present invention, the weight ratio of the first nitrogen-containing phosphate (FR1) to the second nitrogen-containing phosphate (FR2) is 60:40 to 40:60.

[0119] Preferably, the suitable nitrogen-containing flame retardant (FR) is commercially available. A highly suitable example of a commercially available nitrogen-containing flame retardant (FR) is the Phlamoon-1090A flame retardant product manufactured and supplied by SULI Corporation.

[0120] As described above, based on the total weight of the polypropylene composition (C), the polypropylene composition (C) according to the present invention contains 10.0 to 40.0 wt.-%, preferably 18.0 to 35.0 wt.-%, more preferably 20.0 to 38.0 wt.-%, even more preferably 20.0 to 30.0 wt.-%, and even more preferably 20.0 to 27.0 wt.-%, for example 20.0 to 25.0 wt.-%, of a flame retardant (FR).

[0121] In this document, the flame retardant (FR) content refers to the content of flame retardant (FR) supplied by the manufacturer based on the total weight of the polypropylene composition (C). Accordingly, the flame retardant (FR) may contain small amounts of other components, such as additives, flame retardant synergists, and / or carrier media. Therefore, it should be understood that such other components should be included in the flame retardant (FR) content.

[0122] Fiber (F)

[0123] The basic component of the polypropylene composition (C) is fiber (F).

[0124] Preferably, the fiber (F) is selected from glass fiber, carbon fiber, polymer fiber, cellulose fiber, metal fiber, mineral fiber, ceramic fiber, and mixtures thereof. More preferably, the fiber (F) is glass fiber and / or carbon fiber.

[0125] Particularly preferably, the fiber (F) is glass fiber (GF). Preferably, the glass fiber (GF) is chopped glass fiber, also known as short glass fiber (SGF) or chopped strand, and / or long glass fiber (LGF), preferably long glass fiber (LGF) made of glass roving.

[0126] Particularly preferred is that the fiber (F) is short glass fiber (SGF).

[0127] Preferably, after the fiber-reinforced composition (C) is injection molded according to EN ISO 1873-2, the weight-average fiber length of the chopped or short glass fibers (SGF) in the fiber-reinforced composition (C) as determined by FASEP is 0.2 to 1.2 mm, more preferably 0.25 to 1.0 mm, and even more preferably 0.3 to 0.8 mm.

[0128] The initial average length of the short glass fibers (SGF) supplied by the supplier (i.e., the average length of the short fibers (SFG) before melt blending with the propylene polymer (PP), flame retardant (FR) and optional adhesion promoter (AP)) differs from the weight-average fiber length of the short glass fibers (SGF) in the fiber-reinforced composition (C).

[0129] Preferably, the initial average length of the chopped or short glass fibers (SGF) used in the fiber-reinforced composition (C) is 2.0 to 10.0 mm, more preferably 2.3 to 9.0 mm, and even more preferably 2.5 to 8.0 mm, for example 3.0 to 7.0 mm.

[0130] Preferably, the average diameter of the chopped or short glass fibers (SGF) used in the fiber-reinforced composition (C) is 5 to 20 μm, more preferably 6 to 18 μm, and even more preferably 8 to 16 μm.

[0131] Preferably, the initial aspect ratio of the short glass fiber (SGF) is 125 to 650, more preferably 150 to 500, and even more preferably 200 to 450. The aspect ratio refers to the ratio of the average length to the average diameter of the fiber.

[0132] The initial average length and initial average aspect ratio of short glass fiber (SGF) refer to the values ​​of the raw material provided by the supplier.

[0133] Adhesion promoter (AP)

[0134] According to the present invention, the polypropylene composition (C) optionally further comprises an adhesion promoter (AP). The adhesion promoter (AP) is a polar modified polypropylene (PM-PP) homopolymer or copolymer.

[0135] In embodiments of the present invention, when the fiber (F) is glass fiber and / or carbon fiber, the polypropylene composition (C) preferably contains an adhesion promoter (AP).

[0136] Polar-modified polypropylene (PM-PP) homopolymers or copolymers contain low molecular weight compounds with reactive polar groups. Modified polypropylene homopolymers and copolymers are most preferred, for example, propylene with ethylene or with other α-olefins (e.g., C4 to C5). 10Copolymers of α-olefins, because they are highly compatible with the propylene polymer (PP) in the polypropylene composition (C).

[0137] For the structure, the polar modified polypropylene (PM-PP) homopolymer or copolymer is preferably selected from grafted homopolymer or copolymer.

[0138] In this case, polar modified polypropylene (PM-PP) homopolymers or copolymers containing groups derived from polar compounds are preferred, particularly those selected from acid anhydrides, carboxylic acids, carboxylic acid derivatives, primary and secondary amines, hydroxy compounds, oxazolines and epoxides, and ionic compounds.

[0139] Specific examples of the polar compounds include unsaturated cyclic anhydrides and their aliphatic diesters and diacid derivatives. Specifically, maleic anhydride and straight-chain and branched dialkyl maleates selected from C1 to C10, straight-chain and branched dialkyl fumarates selected from C1 to C10, itaconic anhydride, straight-chain and branched dialkyl itaconic acid esters selected from C1 to C10, acrylic acid, maleic acid, fumaric acid, itaconic acid, and mixtures thereof can be used.

[0140] It is particularly preferred to use polypropylene homopolymers or copolymers grafted with maleic anhydride or acrylic acid as polar modified polypropylene (PM-PP) homopolymers or copolymers, i.e. adhesion promoters (AP).

[0141] Modified polymers, i.e. adhesion promoters, can be prepared in a simple manner by reactive extrusion of polymers, for example by reacting with maleic anhydride or acrylic acid in the presence of a free radical generating agent (such as an organic peroxide), as disclosed in US4,506,056, US4,753,997 or EP1805238.

[0142] The preferred content of groups derived from polar compounds in polar modified polypropylene (PM-PP) homopolymers or copolymers (i.e., adhesion promoters (AP)) is 0.5 to 5.0 wt.-%. For example, the content is 0.5 to 4.5 wt.-%, preferably 0.5 to 4.0 wt.-%, and more preferably 0.5 to 3.5 wt.-%.

[0143] For polar modified polypropylene (PM-PP) homopolymers or copolymers (i.e., adhesion promoters (AP)), the preferred melt flow rate MFR2 (230°C, 2.16 kg) is 20.0 to 400 g / 10 min. Particularly preferred is the melt flow rate MFR2 (230°C, 2.16 kg) of the polar modified polypropylene (PM-PP) homopolymer or copolymer, which is 40.0 to 300 g / 10 min, and more preferably 50.0 to 250 g / 10 min.

[0144] In a preferred embodiment of the invention, the adhesion accelerator (AP) is a maleic anhydride-modified polypropylene homopolymer or copolymer and / or an acrylic acid-modified polypropylene homopolymer or copolymer. Preferably, the adhesion accelerator (AP) is a maleic anhydride-modified polypropylene homopolymer and / or an acrylic acid-modified polypropylene homopolymer, and more preferably a maleic anhydride-modified polypropylene homopolymer. For example, suitable polar modified polypropylene (PM-PP) homopolymers or copolymers include, for example, maleic anhydride-grafted polypropylene homopolymers (PP-g-MAH) and acrylic acid-grafted polypropylene homopolymers (PP-g-AA).

[0145] Additive (AD)

[0146] In addition to propylene homopolymer (PP-H), polypropylene blends (PPB), nitrogen-containing flame retardants (FR), fibers (F), and optional adhesion promoters (AP), polypropylene compositions (C) may also contain additives (AD). Typical additives include acid scavengers, antioxidants, colorants, light stabilizers, slip agents, scratch resistant agents, dispersants, processing aids, lubricants, pigments, etc.

[0147] The content of additives in the polypropylene composition (C) of the present invention is generally no more than 5.0 wt.-, preferably 0.5 to 3.5 wt.-.

[0148] These additives are commercially available, and are described, for example, in Hans Zweifel's Handbook of Plastic Additives (6th edition, 2009, pp. 1141-1190).

[0149] Furthermore, according to the present invention, the term "additive (AD)" also includes carrier materials, particularly polymer carrier materials.

[0150] Polymeric carrier material

[0151] Preferably, the polypropylene composition (C) does not contain any polymers other than propylene homopolymer (PP-H), polypropylene blend (PPB), and adhesion promoter (AP), and its content, based on the total weight of the polypropylene composition (C), does not exceed 5.0 wt.-%, preferably not more than 3.0 wt.-%, and more preferably not more than 2.0 wt.-%. Any polymer used as a carrier material for additives (AD) is not included in the content of the polymer compounds described in this invention, but is included in the content of the corresponding additive.

[0152] The polymer carrier material of the additive (AD) is a carrier polymer used to ensure its 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 may be an ethylene homopolymer, an ethylene copolymer derived from ethylene and α-olefin comonomers (e.g., C3 to C8 α-olefin comonomers), a propylene homopolymer, and / or a propylene copolymer derived 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 derived from styrene or its derivatives.

[0153] Article

[0154] The present invention also relates to an article comprising the polypropylene composition (C) defined above or below. In particular, the present invention relates to an article comprising at least 60 wt.-%, more preferably at least 80 wt.-%, even more preferably at least 90 wt.-%, for example at least 95 wt.-% or at least 99 wt.-% of the polypropylene composition (C) defined above or below. In a particularly preferred embodiment, the present invention relates to an article comprising the polypropylene composition (C) defined above or below.

[0155] Preferably, the article is an automotive article in the field of electronic components, such as cable insulation, electrical housing, containers and components of power electronic components for automotive parts and household appliances.

[0156] The present invention will be described in more detail below through the provided embodiments.

[0157] Example

[0158] A. Measurement Method

[0159] Unless otherwise defined, the following terms and measurement methods apply to the above general description of the invention and the following embodiments.

[0160] MFR2 (230°C) was determined according to ISO 1133 (230°C, 2.16 kg load).

[0161] MFR2 (190°C) was determined according to ISO 1133 (190°C, 2.16 kg load).

[0162] Quantitative analysis of microstructure using NMR spectroscopy

[0163] Quantitative nuclear magnetic resonance (NMR) spectroscopy was used to quantify the comonomer content and comonomer sequence distribution of the polymer. A Bruker Advance III 400 NMR spectrometer was used, recordings at 400.15 MHz and 100.62 MHz, respectively. 1 H and13 Quantitative analysis of C in solution state 13 C{ 1 H⁺ NMR spectroscopy. Using... 13 A C-optimized 10mm extended temperature probe was used to record all spectra at 125°C, with nitrogen used for all pneumatic devices. Approximately 200 mg of the material was dissolved in approximately 3 mL of chromium acetylacetone (Cr(acac)3). 1,2 -Tetrachloroethane- d 2 (TCE- d 2) A 65 mM relaxant solution was formed in the solvent (Singh, G., Kothari, A., Gupta, V., Polymer Testing 28 5 (2009), 475). To ensure solution homogeneity, after initial sample preparation in a heating block, the NMR tube was further heated in a rotary thermostat for at least 1 hour. The tube was then inserted into a magnet and rotated at 10 Hz. This setting was chosen primarily for the high resolution and quantification required for accurate ethylene content determination. Standard single-pulse excitation without NOE was employed, using an optimized apex cone 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. RapidCommun. 2007, 28, 1128). A total of 6144 (6 k) transients were acquired for each spectrum.

[0164] Using proprietary computer programs for quantitative analysis 13 C{ 1 The ¹H NMR spectra were processed and integrated, and the relevant quantitative characteristics were determined based on the integration. All chemical shifts were indirectly referenced to the central methylene group of the ethylene block (EEE) at 30.00 ppm using the solvent. 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).

[0165] For propylene homopolymers, all chemical shifts are associated with the methyl isotactic pentad at 21.85 ppm. mmmm (This is for internal reference only.)

[0166] 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.

[0167] Stereoregularity distribution was quantified by integrating the methyl region between 23.6 and 19.7 ppm and correcting for 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).

[0168] Specifically, by subtracting the integral values ​​of representative regional defects and comonomers from specific integral regions of the stereo sequence, the quantitative influence of regional defects and comonomers on the stereoregularity distribution is corrected.

[0169] Isotacticity is determined at the quintanium level and expressed as the percentage of isotopic quintanium (mmmm) sequences to all quintanium sequences:

[0170]

[0171] The presence of two methyl sites at 17.7 and 17.2 ppm indicates the presence of a 2,1 erythromorphic region defect, which is confirmed by other characteristic sites.

[0172] 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).

[0173] Defects in the 2,1 equatorial region were quantified using the average integral of two characteristic methyl sites located at 17.7 and 17.2 ppm, respectively.

[0174] P 21e = ( I e6 + I e8 ) / 2

[0175] The content of primary propylene incorporation 1,2 was quantified by the methyl region, and corrections were made for sites within this region that do not involve primary incorporation and primary incorporation sites not included in this region:

[0176] P 12 = I CH3 + P 12e

[0177] The total propylene content is quantified as the sum of primary propylene admixtures and all other existing regional defects:

[0178] P 总 = P 12 + P 21e

[0179] Based on all propylene, the molar percentage of defects in the 2,1 erythmic region was quantified:

[0180]

[0181] For copolymers, characteristic signals corresponding to ethylene incorporation were observed (Cheng, HN, Macromolecules 17 (1984), 1950).

[0182] 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.

[0183] Using the method of Wang et al. (Wang, WJ., Zhu, S., Macromolecules 33 (2000), 1157), by analyzing... 13 C{ 1The comonomer fraction is quantified by integrating multiple signals across the entire spectral region in the H spectrum. This method is chosen because of its robustness and ability to account for regional defects when needed. Minor adjustments are made to the integration region to improve applicability across the entire range of comonomer contents encountered.

[0184] 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 the integral of known non-existent sites. This method reduces the overestimation of ethylene content in such systems by reducing the number of sites used to determine the absolute ethylene content to the following:

[0185]

[0186] Using this set of sites, the corresponding integral equation becomes:

[0187] E = 0.5(I H +I G + 0.5(I C + I D ))

[0188] The same notation as used in the article by Wang et al. (Wang, WJ., Zhu, S., Macromolecules 33 (2000), 1157) is used. The formula for the absolute content of propylene is unchanged.

[0189] The molar percentage of comonomer added is calculated from the molar fraction:

[0190]

[0191] Calculate the weight percentage of comonomer added based on mole fraction:

[0192]

[0193] 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 the ability to make minor adjustments to the integration region to improve its applicability to a wider range of copolymer contents.

[0194] Crystallization extraction (CRYSTEX)

[0195] Determination of crystalline and soluble fractions and their respective characteristics (IV and ethylene content).

[0196] The crystalline fraction (CF) and soluble fraction (SF) in polypropylene compositions, as well as the comonomer content and intrinsic viscosity of each fraction, were analyzed using a CRYSTEX instrument from PolymerChar (Valencia, Spain). Details of this technique and method can be found in the literature (Ljiljana Jeremic, Andreas Albrecht, Martina Sandholzer and 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).

[0197] The crystalline and non-crystalline fractions were separated by a temperature cycle of dissolution at 160 °C, crystallization at 40 °C, and redissolution in 1,2,4-trichlorobenzene at 160 °C. SF and CF were quantified and ethylene content (C2) was determined using an integrated infrared detector (IR4), and intrinsic viscosity (iV) was determined using an online 2-capillary viscometer.

[0198] 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 IR4 detectors is used to determine the concentration and ethylene content in ethylene-propylene copolymers. The IR4 detector uses a series of eight known ethylene contents (ranging from 2 to 69 wt%). 13 The calibration was performed using EP copolymers (measured by C-NMR), each copolymer having a different concentration ranging from 2 to 13 mg / ml. To simultaneously meet two characteristics (i.e., concentration and ethylene content) for the expected multiple polymer concentrations during Crystex analysis, the following calibration equation was applied:

[0199]

[0200] (Equation 1)

[0201]

[0202] (Equation 2)

[0203] The constants a to e in Equation 1 and the constants a to f in Equation 2 are determined by least squares regression analysis.

[0204] Use the following relationship to convert CH3 / 1000C to ethylene content (wt.-%):

[0205]

[0206] (Equation 3)

[0207] The amounts of soluble fraction (SF) and crystalline fraction (CF) were correlated, respectively, with the amounts of "cold xylene soluble fraction" (XCS) and "cold xylene insoluble fraction" (XCI) determined according to the standard gravimetric method of ISO 16152 via XS calibration. XS calibration was performed by detecting various EP copolymers with XS contents ranging from 2 to 31 wt.%. The determined XS calibration was linear.

[0208] (Equation 4)

[0209] The intrinsic viscosity (iV) of the EP copolymer masterbatch and its soluble and crystalline fractions was determined using an online 2-capillary viscometer and correlated with the corresponding iV determined in decahydronaphthalene according to standard methods of ISO 1628-3. Calibration was performed using various EP and PP copolymers with iV = 2-4 dL / g. The determined calibration curves were linear.

[0210] (Equation 5)

[0211] The sample to be analyzed was weighed at a concentration of 10 to 20 mg / ml. To avoid the possibility of injecting gels and / or polymers (e.g., PET and PA) that are insoluble in TCB at 160°C, the weighed sample was placed in a stainless steel mesh (MW 0.077 / D 0.05 mm).

[0212] After automatically filling the sample vial with 1,2,4-TCB containing 250 mg / L 2,6-tert-butyl-4-methylphenol (BHT) (as an antioxidant), dissolve the sample at 160°C until completely dissolved, typically for 60 minutes with continuous stirring at 400 rpm. To prevent sample degradation, the polymer solution is covered with a nitrogen atmosphere during the dissolution process.

[0213] A certain volume of sample solution is injected into a column filled with an inert support, where sample crystallization occurs and the soluble fraction is separated from the crystallized portion. This process is repeated twice. During the first injection, the entire sample is measured at high temperature to determine the iV [dl / g] and C2 [wt.%] of the PP composition. During the second injection, the soluble fraction (low temperature) and the crystalline fraction (high temperature) are measured by the crystallization cycle (wt.% SF, wt.% C2, iV).

[0214] Intrinsic viscosity

[0215] The intrinsic viscosity was determined in decahydronaphthalene at 135°C according to DIN ISO 1628 / 1 (October 1999).

[0216] Density: Measured on a molded plate according to ISO 1183.

[0217] DSC analysis, melting temperature (T) m ) and heat of fusion (H f ), crystallization temperature (T) c ) and heat of crystallization (H c Samples ranging from 5 to 7 mg were analyzed using a TAInstrument Q200 differential scanning calorimeter (DSC). The DSC was operated according to ISO 11357 / Part 3 / Method C2 with 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 heat of crystallization (H c The melting temperature (T) is determined by the cooling step, while the melting temperature (T) is determined by the melting step. m ) and heat of fusion (H m The value is determined by the second heating step.

[0218] Xylene cold solubles (XCS, wt.-%): The content of xylene cold solubles (XCS) is determined at 25°C according to ISO 16152 (first edition, 1 July 2005).

[0219] Charpy notched impact strength was determined at 23°C according to ISO 179-1 / 1eA for injection-molded specimens (80×10×4mm) prepared according to EN ISO 1873-2.

[0220] Tensile properties were determined on injection-molded specimens (dog-bone shape, 4 mm thickness) 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 temperatures of 23 °C, 80 °C, and 120 °C. Yield stress was determined at a strain rate of 50 mm / min and temperatures of 23 °C, 80 °C, and 120 °C.

[0221] Flexural modulus was determined according to ISO 178 Method A (3-point bending test) on an 80 mm × 10 mm × 4 mm specimen. A test speed of 2 mm / min and a span length of 16 times the thickness were used, as per the standard. The test temperature was 23 ± 2 °C. Injection molding was performed according to ISO 19069-2, with all materials using a melt temperature of 230 °C, regardless of the material melt flow rate.

[0222] Ash content was determined according to ISO 3451-1 (1997).

[0223] Limonene detection

[0224] Determination of limonene

[0225] The determination of benzene and limonene was based on a static headspace (HS) method. This analysis combined screening using an HS injector, gas chromatography (GC), and mass spectrometry (MS).

[0226] Samples were delivered to the laboratory in sealed aluminized polyethylene (PE) bags. Before analysis, the samples were freeze-ground, and 2.000 ± 0.100 g of sample was weighed, placed in a 20 mL HS bottle, and sealed. Each sample was analyzed twice.

[0227] HS / GC / MS parameters

[0228] •HS parameters (Agilent G1888 headspace sampler)

[0229] Sample vial equilibration time: 120 minutes (samples), 5 minutes (standards)

[0230] Heating chamber temperature: 100℃ (samples), 200℃ (standards)

[0231] Ambient temperature: 110℃ (sample), 205℃ (standard)

[0232] Transmission line temperature: 120℃ (sample), 210℃ (standard)

[0233] low oscillation

[0234] • GC parameters (Agilent 7890A GC system)

[0235] Column: ZB-WAX 7HG-G007-22 (30m×250µm×1µm)

[0236] Carrier gas: Helium 5.0

[0237] Flow rate: 2 ml / min

[0238] Traffic split: 5:1

[0239] GC temperature program: 35℃ for 0.1 min

[0240] Increase the temperature to 250℃ at a rate of 10℃ / min.

[0241] Hold at 250℃ for 1 minute

[0242] • MS Specifications (Agilent 5975C Inert XL MSD)

[0243] Acquisition Mode: Scan

[0244] Scan parameters:

[0245] Low quality number: 20

[0246] High quality number: 200

[0247] Threshold: 10

[0248] • Software / Data Evaluation

[0249] MSD ChemStation E.02.02.1431

[0250] MassHunter GC / MS data acquisition software B.07.05.2479

[0251] AMDIS GC / MS Analysis Software Version 2.71

[0252] NIST / EPA / NIH Mass Spectrometry Library (2011 Edition)

[0253] NIST Mass Spectrometry Search Program Version 2.0

[0254] •AMDIS deconvolution parameters

[0255] Minimum matching factor: 80

[0256] Threshold: Low

[0257] Scanning direction: From high to low

[0258] Data file format: Agilent file

[0259] Instrument type: Quadrupole

[0260] Component width: 20

[0261] Adjacent peak subtraction: 2

[0262] Resolution: High

[0263] Sensitivity: Extremely High

[0264] Peak shape requirement: Medium

[0265] Solvent tailing: 91 m / z

[0266] Column bleed: 207 m / z

[0267] Minimum model peak: 2

[0268] Minimum S / N: 10

[0269] Minimum specific peak: 0.5

[0270] • MSD ChemStation integration parameters

[0271] Integrator: ChemStation

[0272] Initial minimum peak area: 0

[0273] Initial peak width: 0.005

[0274] Shoulder peak detection: Off

[0275] Initial threshold: 10.5

[0276] In this study, the expression "below the detection limit (<LOD)" refers to the case where 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 are only related to the measured sample, measurement time, and applied parameters.

[0277] Standard solution

[0278] To perform accurate identification and comparison with the (lowest) odor detection threshold (ODT), limonene standard was used.

[0279] In HS / GC / MS analysis, 5 μl of the corresponding standard was injected into a 20 ml HS sample vial, sealed, and then detected.

[0280] Assuming complete vaporization of the standard substance, the concentration of limonene in HS was estimated as shown in the following table.

[0281] Table: Calibration standards and ODT

[0282]

[0283] Data evaluation

[0284] Concentration of the analyte in HS was calculated (Equation 1) by considering the amount of substance and the available HS volume (Equation 1).

[0285] Formula 1

[0286] 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.

[0287] Formula 2

[0288] 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).

[0289] Formula 3

[0290] Furthermore, the odor relevance of the analytes in the HS above the polymer sample was estimated using odor activity value (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 the odor at a given HS temperature.

[0291] Formula 4

[0292] Factors to consider and limitations

[0293] 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.

[0294] OAV is based on the assumption that there is a certain correlation between HS parameters and the measurement conditions of ODT. Of course, this is not entirely applicable, because such experiments do not necessarily use a temperature setting of 100°C, thus limiting their practical value.

[0295] Nevertheless, this method can at least demonstrate the correlation between defined marker substances and odor.

[0296] Given all the assumptions and limitations mentioned, the concentrations and odor activity values ​​measured in the HS above the sample can only be used as rough estimates.

[0297] References

[0298] [1]Van Gemert LJ, Odour Thresholds: Compilations of odourthreshold values ​​in air, water and other media, Utrecht, Oliemans Punter &Partners BV, 2011.

[0299] The average fiber diameter was determined according to ISO 1888:2006(E) Method B.

[0300] Weight-average fiber length and fiber length distribution were determined according to the FASEP (FAser (German: fiber) SEParation) method on injection-molded specimens prepared according to ENISO 1873-2. Fibers were separated from the polymer matrix by pyrolysis in a TGA furnace (625°C for glass fibers, 500°C for carbon fibers) or by solution and physical separation. The separated fibers were suspended in deionized water, and the suspension was diluted until fiber quantity and overlap reached equilibrium. The average fiber length was determined by grayscale image processing using FASEP 1.9.44.0 (IDM system, Darmstadt, Germany), and statistical analysis was performed by calculating the average fiber length and fiber length distribution. Accurate results were obtained for images with a small number of fiber clusters and arbitrary fiber cuts. This was achieved by fractionating specific fibers with water. The fraction for glass fibers should be equal to or less than 30 mg / L, and the fraction for carbon fibers should be equal to or less than 20 mg / L. The number of fiber clusters relative to the fraction of free fibers should be less than 20% for short fibers and less than 15% for long fibers.

[0301] During the evaluation process, FASEP software (ImageProPlus with FASEP module) was used to separate the fibers from the background, remove dust and other irrelevant features, separate fibers when they overlapped, and automatically measure the length of each fiber.

[0302] Average fiber length Ln and weight-average fiber length Lp were determined according to ISO 22314:05:2006:

[0303]

[0304] In addition to the settings used, the evaluation report must include the following values:

[0305] • The total fiber count after merging all images for each sample

[0306] •Ln, Lp (as defined above)

[0307] • Lmin and Lmax of the fiber after merging all images for each sample

[0308] • Fiber length distribution

[0309] • Fiber quality

[0310] • Local fiber gradation

[0311] The UL94 vertical burning test was conducted according to UL94:2016. Samples were injection molded with dimensions of 125±5 mm in length, 13.0±0.5 mm in width, and a thickness of 0.8 to 3.2 mm (1.5 mm thickness was used in the examples). According to Part 1, samples were conditioned for 48 hours at a constant temperature of 23±2°C and 50±10% humidity. According to Part 2, samples were conditioned for 168 hours in an air-circulating oven at 70±1°C, and then cooled to room temperature in a desiccator for at least 4 hours before testing. The test must be conducted within 30 minutes of sample conditioning. The sample was suspended vertically in the test chamber, and an initial ignition was performed for 10 seconds, followed by a second ignition for 10 seconds. The burning time after each ignition was recorded, and the presence of afterglow, ignition of burning droplets on the bottom of the chamber, and spread of the flame or afterglow to the fixture were observed. The rating was V-0, V-1, V-2, or no rating depending on the thickness of the sample.

[0312] Experiment B

[0313] Polypropylene blends (PPB)

[0314] 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, their properties are expressed as ranges.

[0315] Table 1: Properties of Polypropylene / Polyethylene Blends (Blends PPB-1 and PPB-2)

[0316]

[0317] multiphase propylene copolymer HECO

[0318] The catalyst used to prepare the multiphase propylene copolymer HECO is a Ziegler-Natta catalyst, which is commercially available from LyondellBasell (IT) under the trade name ZN180M.

[0319] HECO was prepared using a configuration of prepolymerization / loop reactor / gas phase reactor 1 / gas phase reactor 2, followed by a granulation step.

[0320] For HECO, the catalyst system defined above is used in combination with triethylaluminum (TEAL) as a co-catalyst and dicyclopentadienyldimethoxysilane (donor D) as an external donor.

[0321] The polymerization conditions are shown in Table 2.

[0322] Table 2: Polymerization conditions of HECO

[0323]

[0324]

[0325] The multiphase copolymer HECO was compounded at 220°C in a Coperion ZSK 47 co-rotating twin-screw extruder with the addition of 0.15 wt.% of an antioxidant (Irganox B215FF from BASF AG, Germany; this is a 1:2 mixture of pentaerythritol tetrakis(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 wt.% of calcium stearate (CAS No. 1592-23-0, available from Faci, Italy).

[0326] Preparation of polypropylene composition (C)

[0327] PP1 or HECO (for RE1) and PPB, together with flame retardant composition (FR), glass fiber (GF), adhesion promoter (AP) and additive (AD), are melt-blended in a co-rotating twin-screw extruder at the amounts shown in Table 3 below.

[0328] Table 3: Composition and characteristics of comparative examples and embodiments of the invention

[0329]

[0330] PP1 is Borealis' commercial propylene homopolymer HL504FB, with a melt flow rate (ISO 1133; 230℃, 2.16kg load) of 450g / 10min, a melting temperature Tm of 161℃, and a flexural modulus of 1519MPa. It is produced by viscosity-reducing pyrolysis of a matrix polymer prepared with a post-phthalate Ziegler-Natta catalyst.

[0331] FR is Phlamoon-1090A, a commercial flame retardant composition from SULI, containing 55 to 60 wt.% melamine polyphosphate and 40 to 55 wt.% piperazine pyrophosphate.

[0332] GF is the commercial product ECS03T-480H of Nippon Electric Glass Co., Ltd., with a wire diameter of 13.0μm and a wire length of 3mm.

[0333] AP is SCONA TPPP 8112 GA, an adhesive accelerator manufactured by Scona Corporation. It is a polypropylene functionalized with maleic anhydride, with a maleic anhydride content of 1.4 wt.- and a melt flow rate (190°C, 2.16 kg) greater than 80 g / 10 min.

[0334] CB is a masterbatch containing 40 wt.% carbon black.

[0335] AO1 is an antioxidant 2,2'-oxamidobis-(ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, commercially available under the brand name Naugard XL-1 from Addivant.

[0336] AO2 is the antioxidant tris(2,4-di-tert-butylphenyl) phosphite, commercially available under the brand name Irgafos 168 from BASF.

[0337] AO3 is the antioxidant pentaerythritol tetrakis(3-(3',5'-di-tert-butyl-4-hydroxyphenyl)propionate), commercially available under the name Irganox 1010 from BASF.

[0338] Table 4 summarizes the flame retardant and mechanical properties of the comparative composition and the inventive composition.

[0339] Table 4: Performance of Comparative Examples and Embodiments of the Invention

[0340]

[0341] The UL94 vertical burning test was conducted according to the conditions described in Part 1 of the “Measurement Method - UL94 Vertical Burning Test” section above, i.e., the sample was conditioned for 48 hours at a constant temperature of 23±2℃ and a humidity of 50±10%.

[0342] The UL94 vertical burning test was conducted according to the conditions described in Part 2 of the “Measurement Methods - UL94 Vertical Burning Test” section above, namely, the sample was 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.

[0343] nd = Undetermined

[0344] Examples IE1 and IE2 of the invention, which contain 20.0 wt.-% of mixed plastic polypropylene blends PPB-1 and PPB-2, unexpectedly exhibited performance comparable to that of Reference Example RE1, which contained only the original multiphase propylene copolymer HECO as a propylene-based polymer.

[0345] Comparative Example CE1, containing 21.0 wt.% of the blended polypropylene polypropylene blend PPB-1, failed the UL94 vertical burning test under Condition 2. Comparative Example CE2, containing 22.0 wt.% of the blended polypropylene polypropylene blend PPB-1, failed the UL94 vertical burning test under both Condition 1 and Condition 2. Therefore, these compositions are not suitable for use as flame-retardant materials for electronic enclosures.

Claims

1. A polypropylene composition (C), wherein, The polypropylene composition (C) comprises: i) 5.0 to 40.0 wt.% of propylene homopolymer (PP-H), wherein the propylene homopolymer (PP-H) has a melt flow rate MFR2 (230°C, 2.16 kg) of at least 75.0 g / 10 min as determined according to ISO 1133; ii) 5.0 to 20.5 wt.% of a mixed plastic polypropylene blend (PPB), wherein the mixed plastic polypropylene blend (PPB) 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; iii) 10.0 to 40.0 wt.% flame retardant (FR); iv) 10.0 to 40.0 wt.% of fiber (F); and v) 0.0 to 5.0 wt.% of adhesion promoter (AP); 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 a melt flow rate (MFR2) of 2.5 to 30.0 g / 10 min, preferably 5.0 to 25.0 g / 10 min, and more preferably 10.0 to 22.5 g / 10 min, as determined according to ISO 1133 at 2.16 kg and 230 °C.

3. The polypropylene composition (C) according to claim 1 or 2, wherein, The polypropylene composition (C) has a Charpy notched impact strength of at 23°C of at least 6.5 kJ / m, as determined according to ISO 179-1 / 1eA. 2 For example, 6.5 to 15.0 kJ / m 2 Preferably, it is 6.7 to 12.5 kJ / m 2 More preferably, it is 7.0 to 10.0 kJ / m 2 .

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 as determined by ISO 527-1A at 23°C: • The tensile modulus is at least 5500 MPa, for example, 5500 to 10000 MPa, preferably 6000 to 9500 MPa, and more preferably 6250 to 9000 MPa; • Tensile strength is at least 50 MPa, for example 50 to 100 MPa, preferably 55 to 95 MPa, more preferably 60 to 90 MPa; • The tensile stress at break is at least 1.7%, for example, from 1.7 to 5.0%, preferably from 2.0 to 4.5%, more preferably from 2.2 to 4.0%.

5. The polypropylene composition (C) according to any one of claims 1 to 4, wherein, The polypropylene composition (C) has one or more of the following properties: • After 48 hours of adjustment according to condition 1, achieve UL94 classification V-0 in the UL94 flame retardancy test; • After a 168-hour adjustment period according to Part 2 of the conditions, it achieves UL94 Class V-0 rating in the UL94 flame retardancy test. The above properties were measured 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.

6. The polypropylene composition (C) according to any one of claims 1 to 5, wherein, i) The fluoropolymer content in the polypropylene composition (C) is not more than 0.5 wt.-%, more preferably not more than 0.1 wt.-%, even more preferably not more than 0.01 wt.-%, for example 0.001 wt.-%, and most preferably free of fluoropolymers; and / or ii) The nitrogen-containing flame retardant (FR) is halogen-free.

7. The polypropylene composition (C) according to any one of claims 1 to 6, wherein, The mixed plastic polypropylene blend (PPB) has the following characteristics: • The crystalline fraction (CF) content, as determined by CRYSTEX QC analysis, is 80.0 to 96.0 wt.-%, preferably 82.5 to 95.5 wt.-%. • The soluble fraction (SF) content, as determined by CRYSTEX QC analysis, is 4.0 to 20.0 wt.-%, preferably 4.5 to 17.5 wt.-%. • The crystalline fraction (CF) is based on quantitative... 13 The ethylene content (C2(CF)) determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy is 1.0 to 15.0 wt.-%, preferably 1.5 to 12.5 wt.-%. • The intrinsic viscosity (iV(CF)) of the crystalline fraction (CF) is 0.9 to 2.1 dl / g, preferably 1.0 to 2.0 dl / g, and more preferably 1.1 to 1.9 dl / g; • The soluble fraction (SF) is based on quantitative... 13 The ethylene content (C2(SF)) determined by FT-IR spectroscopy calibrated by C-NMR spectroscopy is 15.0 to 40.0 wt.-%, preferably 20.0 to 37.5 wt.-%; and • The intrinsic viscosity (iV(SF)) of the soluble fraction (SF) is 0.9 to 2.2 dl / g, preferably 1.0 to 2.1 dl / g, and more preferably 1.1 to 2.0 dl / g.

8. The polypropylene composition (C) according to any one of claims 1 to 7, 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 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, it is 910 to 1010 kg / m³ 3 ; • The limonene content, as determined by solid-phase microextraction (HS-SPME-GC-MS), ranges 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 .

9. The polypropylene composition (C) according to any one of claims 1 to 8, wherein, The flame retardant (FR) is a nitrogen-containing flame retardant (FR), more preferably comprising a first nitrogen-containing phosphate (FR1) and a second nitrogen-containing phosphate (FR2), and optionally, the weight ratio of the first nitrogen-containing phosphate (FR1) to the second nitrogen-containing phosphate (FR2) is 60:40 to 40:

60.

10. The polypropylene composition (C) according to claim 9, wherein, The first nitrogen-containing phosphate (FR1) is melamine polyphosphate, and the second nitrogen-containing phosphate (FR2) is piperazine pyrophosphate.

11. The polypropylene composition (C) according to any one of claims 1 to 10, wherein, The propylene homopolymer (PP-H) has a melt flow rate (MFR2, 230°C, 2.16 kg) of 105 to 600 g / 10 min as determined by ISO 1133.

12. The polypropylene composition (C) according to any one of claims 1 to 11, wherein, The fiber (F) is glass fiber (GF), preferably short glass fiber (SGF), and the weight-average fiber length of the glass fiber (GF) after injection molding according to EN ISO 1873-2, as determined by the FASEP method described in "Method", is 0.2 to 1.2 mm.

13. The polypropylene composition (C) according to any one of claims 1 to 12, wherein, The adhesion promoter (AP) is polar modified polypropylene (PM-PP), which is a propylene homopolymer or copolymer grafted with maleic anhydride, and the polar modified polypropylene (PM-PP) has a melt flow rate (MFR2, 230°C, 2.16 kg) of at least 20.0 g / 10 min as determined by ISO 1133.

14. The polypropylene composition (C) according to any one of claims 1 to 13, wherein, The total content of the propylene polymer (PP), flame retardant (FR), fiber (F), and optional adhesion promoter (AP) is at least 90 wt.- 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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