Controllable rheology hybrid plastic polypropylene-based blends

Abstract

The present invention relates to a controlled rheology polypropylene composition derived from a polypropylene composition comprising a mixed plastic polypropylene-based blend having a melt flow rate MFR2 of at least 10 g / 10 min and an emission of volatile organic compounds (VOC) of no more than 2.8 [mu] g / g over a time interval of 3.0-8.5 minutes as determined by GC-MS; the invention also relates to a process for the manufacture of said controlled rheology polypropylene composition, to an article comprising said controlled rheology polypropylene composition, and to the use of said controlled rheology polypropylene composition for the manufacture of an article comprising a hybrid plastic polypropylene-based blend.

Description

Technical Field

[0001] The present invention relates to a controlled rheology polypropylene composition, which is derived from a polypropylene composition comprising a mixed plastic polypropylene-based blend, and has a melt flow rate MFR2 of at least 10 g / 10 min and a volatile organic compound (VOC) emission of no more than 2.8 μg / g within a GC-MS time interval of 3.0-8.5 minutes; the present invention relates to a method for manufacturing the controlled rheology polypropylene composition, an article comprising the controlled rheology polypropylene composition, and the use of the controlled rheology polypropylene composition for the manufacture of an article comprising a mixed plastic polypropylene-based blend. Background Art

[0002] Plastics, with their inherent versatility, play a vital role in a sustainable and resource-efficient economy. However, as more and more plastics are manufactured and used in a linear economy, plastic waste is now seen as a serious environmental and social issue. To this end, it is important to form a circular economy where plastic waste gets a second life, i.e. it is recycled. This not only avoids leaving plastic waste in the environment, but also recovers its value. In 2017, the European Commission confirmed that it would focus on the production and use of plastics. The EU's goals are: 1) by 2025, at least 50% of all plastic packaging used in the EU should be recycled; 2) by 2030, all plastic packaging on the EU market should be reusable or easily recyclable. This has prompted brand owners and plastic processors to seek solutions for recycled content or virgin / recycled blends. On January 1, 2021, the EU began to impose a new tax on non-recycled plastic packaging, at a rate of €0.80 / kg, calculated on the weight of non-recycled plastic packaging.

[0003] Therefore, there is an urgent need to find ways to recycle plastic waste. However, the quality of recycled plastics is usually inferior to that of virgin plastics due to degradation, contamination and mixing of different plastics. On the other hand, unlike reactor grades where processability and mechanical properties can be controlled by adjusting polymerization conditions, the processability and mechanical properties of recyclates depend largely on the raw materials and processing. Typically, unmodified recyclates have only a rather narrow range of MFR values ​​(i.e. melt viscosity). Blending them with virgin polymers or treating them with peroxides are common methods to adjust their properties, especially in the case of polyolefins.

[0004] The use of free radical formers to modify the melt viscosity (rheology) of polyolefins is a well-known method for virgin polyolefins. Whether the result is a decrease in molecular weight (degradation) or an increase in molecular weight (crosslinking) depends primarily on the chemical structure of the polyolefin. During polymer processing, the reaction of polypropylene (PP) polymers with free radical formers generally results in polymer degradation, while polyethylene polymers tend to crosslink.

[0005] The controlled degradation of polypropylene to obtain products with lower molecular weight and narrower molecular weight distribution is an important commercial process for producing "controlled rheology" polypropylene.

[0006] Known degradation processes are carried out under the action of heat (especially at temperatures above 280°C) or in the presence of free radical generators. In processing technology, free radical-induced processes are carried out in extruders or injection molding machines at temperatures above 180°C. The free radical generators used are organic peroxides, which are added in diluted form (PP masterbatch, diluted in oil, stabilized on an inorganic support) or directly in liquid form during the processing step. Under the given processing conditions, the peroxides decompose into free radicals, which initiate chain cleavage reactions and form polymers with the desired rheological properties (melt viscosity). The degradation of polypropylene to form products with lower molecular weight (higher melt flow rate (MFR)) and, most importantly, lower melt viscosity is generally referred to as a viscosity-breaking or visbreaking process. Polypropylenes rheologically modified in this way are generally referred to as "controlled rheology" polypropylenes.

[0007] Although peroxides are widely used to modify the rheological properties of polyolefins, they also have disadvantages, such as increased emissions and strict safety regulations that must be followed during storage, handling and transportation. Many peroxides are subject to specific regulatory measures, such as registration under GHS / CLP, specific exposure limits applicable in different countries, etc. (Regulation (EC) No 1272 / 2008 of the European Parliament and of the Council on classification, labelling and packaging of substances and mixtures, amending and repealing Directives 67 / 548 / EEC and 1999 / 45 / EC, and amending Regulation (EC) No 1907 / 2006).

[0008] Controlled rheology polypropylene grades are primarily used for films, fiber applications and injection molding applications where low melt viscosity is a prerequisite for economical processing. Today, a wide range of melt viscosities or molecular weights is required in processing technology.

[0009] Therefore, there is a need to produce a controlled rheology polypropylene composition derived from a polypropylene composition comprising a mixed plastic polypropylene-based blend, which does not show the disadvantages of peroxide-modified polypropylene compositions.

[0010] The present invention provides a controlled rheology polypropylene composition derived from a polypropylene composition comprising a mixed plastic polypropylene-based blend, having a melt flow rate MFR2 of at least 10 g / 10 min and surprisingly showing a low total volatile organic compound (VOC) content, in particular a low volatile organic compound (VOC) emission within a time interval of 3.0 to 8.5 minutes as obtained by GC-MS. Summary of the invention

[0011] The present invention relates to a controlled rheology polypropylene composition (CR-PP) derived from a polypropylene composition (PP) comprising a mixed plastic polypropylene-based blend, wherein the controlled rheology polypropylene composition has:

[0012] a melt flow rate MFR2 measured at 230°C and 2.16 kg according to ISO 1133-1:2011 of at least 10 g / 10 min, such as 10-250 g / 10 min, preferably 15-225 g / 10 min, more preferably 25-200 g / 10 min, still more preferably 40-175 g / 10 min, most preferably 65-150 g / 10 min, wherein the ratio of the melt flow rate MFR2(CR-PP) of the controlled rheology polypropylene composition to the melt flow rate MFR2(PP) of the virgin polypropylene composition is 1.5-30.0; and

[0013] The volatile organic compound (VOC) emission measured by GC-MS within a GC-MS time interval of 3.0-8.5 minutes does not exceed 2.8 μg / g, for example 1.5-2.7 μg / g, preferably 1.7-2.6 μg / g, more preferably 2.0-2.5 μg / g.

[0014] Furthermore, the present invention relates to a method for producing the above or below controlled rheology polypropylene composition, comprising the following steps:

[0015] - Providing a polypropylene composition comprising a mixed plastic polypropylene-based blend;

[0016] - mixing the polypropylene composition with a non-peroxide rheology control agent;

[0017] - Compounding the polypropylene composition with a non-peroxide rheology control agent at a maximum temperature below 250°C, preferably 160-230°C, more preferably 200-220°C.

[0018] Furthermore, the present invention relates to an article comprising the controlled rheology polypropylene composition as described above or below.

[0019] Furthermore, the present invention relates to the use of the controlled rheology polypropylene composition as described above or below for the manufacture of articles comprising a mixed plastic polypropylene-based blend.

[0020] definition

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those of ordinary skill in the art to which the invention belongs. Although any method and material similar or equivalent to the methods and materials described herein can be used in practice to test the present invention, preferred materials and methods are described herein. When describing and claiming the present invention, the following terms will be used according to the definitions hereinafter. Unless otherwise expressly stated, "a", "an" etc. refer to more than one.

[0022] Mixed plastics are defined as the presence of small amounts of compounds not normally present in virgin polypropylene blends, such as polystyrene, polyamides, polyesters, wood, paper, limonene, aldehydes, ketones, fatty acids, metals, other inorganics (such as chalk or talc) and / or long-term decomposition products of stabilizers. Virgin polypropylene blends are blends directly from the production process without intermediate use.

[0023] By definition, "mixed plastics" may be equated to detectable amounts of polystyrene and / or polyamide and / or limonene and / or fatty acids.

[0024] Mixed plastics can therefore come from post-consumer waste and industrial waste, rather than virgin polymers. Post-consumer waste refers to items that have completed at least their first use cycle (or life cycle), i.e. have served their first purpose. In contrast, industrial waste refers to starter lump, wash-off material and manufacturing waste, respectively conversion waste, which usually do not reach the hands of consumers.

[0025] Polymer blends are mixtures of two or more polymer components. In general, blends can be 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 dry blending of polymer components such as polymer powders and / or composite polymer particles, or can be melt blending by melt mixing of polymer components.

[0026] Polypropylene refers to a polymer consisting of units derived from propylene in an amount exceeding 50 mol%.

[0027] A controlled rheology polypropylene composition is a polypropylene composition, the rheology of which, for example expressed in terms of its molecular weight Mw or melt flow rate MFR2, is controlled by degradation caused by a rheology control agent. DETAILED DESCRIPTION

[0028] In one aspect, the present invention relates to a controlled rheology polypropylene composition (CR-PP) derived from a polypropylene composition (PP) comprising a mixed plastic polypropylene-based blend, wherein the controlled rheology polypropylene composition has:

[0029] a melt flow rate MFR2 measured at 230°C and 2.16 kg according to ISO 1133-1:2011 of at least 10 g / 10 min, such as 10-250 g / 10 min, preferably 15-225 g / 10 min, more preferably 25-200 g / 10 min, still more preferably 40-175 g / 10 min, most preferably 65-150 g / 10 min, wherein the ratio of the melt flow rate MFR2(CR-PP) of the controlled rheology polypropylene composition to the melt flow rate MFR2(PP) of the virgin polypropylene composition is 1.5-30.0; and

[0030] The volatile organic compound (VOC) emission within a time interval of 3.0-8.5 minutes determined by GC-MS does not exceed 2.8 μg / g, for example, 1.5-2.7 μg / g, preferably 1.7-2.6 μg / g, more preferably 2.0-2.5 μg / g.

[0031] The controlled rheology polypropylene composition is derived from a polypropylene composition comprising a mixed plastic polypropylene-based blend.

[0032] In the following the non-modified polypropylene composition comprising the mixed plastic polypropylene composition is also referred to as "virgin polypropylene composition".

[0033] The original polypropylene composition is modified in the presence of a non-peroxide rheology control agent to obtain a controlled rheology polypropylene composition as described in the method section below.

[0034] The mixed plastic polypropylene-based blends present in the original (non-modified) polypropylene composition are properly characterized by CRYSTEX QC analysis. In the CRYSTEX QC analysis, a crystalline fraction (CF) and a soluble fraction (SF) are obtained, the monomer and comonomer content of these fractions as well as the intrinsic viscosity (iV) can be quantified and analyzed.

[0035] Mixed plastic polypropylene-based blends showed the following properties in CRYSTEX QC analysis:

[0036] - a crystalline fraction (CF) content of 85.0-96.0 wt.-%, preferably 86.5-95.5 wt.-%, more preferably 88.0-95.0 wt.-%, determined according to CRYSTEX QC analysis; and

[0037] - the soluble fraction (SF) content determined according to CRYSTEX QC analysis is 4.0-15.0 wt.-%, preferably 4.5-13.5 wt.-%, more preferably 5.0-12.0 wt.-%.

[0038] The crystalline fraction (CF) has one or more, preferably all, of the following properties:

[0039] - By quantitative 13 an ethylene content (C2(CF)) of 3.0-12.5 wt.-%, preferably 4.0-11.0 wt.-%, more preferably 5.0-10.0 wt.-%, as determined by FT-IR spectroscopy calibrated with C-NMR spectroscopy; and / or

[0040] The intrinsic viscosity (iV(CF)) measured in decalin at 135° C. according to DIN ISO 1628 / 1 is preferably from 1.2 to 2.4 dl / g, more preferably from 1.3 to 2.2 dl / g, still more preferably from 1.4 to 2.0 dl / g.

[0041] The soluble fraction (SF) has one or more, preferably all, of the following characteristics:

[0042] - By quantitative 13 The ethylene content (C2(SF)), determined by FT-IR spectroscopy calibrated with C-NMR spectroscopy, is preferably in the range of 20.0 to 40.0 wt.-%, preferably in the range of 22.0 to 37.0 wt.-%, more preferably in the range of 24.0 to 34.0 wt.-%; and / or

[0043] The intrinsic viscosity (iV(SF)) measured in decalin at 135° C. according to DIN ISO 1628 / 1 is from 0.9 to 2.0 dl / g, preferably from 1.0 to 1.9 dl / g, more preferably from 1.1 to 1.7 dl / g.

[0044] Preferably, the mixed plastic polypropylene-based blend comprises polypropylene and polyethylene.

[0045] The weight ratio of polypropylene to polyethylene is generally 99.5:0.5-70:30; preferably 99:1-80:20; more preferably 97:3-82:18.

[0046] The mixed plastic polypropylene-based blend preferably comprises more than 50 mol-% of units derived from propylene.

[0047] Preferably, the mixed plastic polypropylene based blend comprises units derived from ethylene in an amount of 2.5-20.0 wt.-%, more preferably 4.0-17.5 wt.-%, still more preferably 5.0-15.0 wt.-%, determined by NMR.

[0048] Furthermore, the mixed plastic polypropylene-based blend preferably has one or more, preferably all, of the following properties:

[0049] - melt flow rate MFR2 (230°C, 2.16 kg, ISO1133) is 8.0-30.0 g / 10 min, preferably 9.0-25.0 g / 10 min, more preferably 12.0-20.0 g / 10 min; and / or

[0050] - a limonene content of 0.1-50 ppm as determined using solid phase microextraction (HS-SPME-GC-MS); and / or

[0051] - a chalk content of 0-1.5 wt%, preferably 0.01-1.0 wt%, more preferably 0.1-0.7 wt%, as determined by IR; and / or

[0052] - a polyamide content of 0-1.5 wt%, preferably 0-1.0 wt%, more preferably 0-0.7 wt%, as determined by IR; and / or

[0053] - a polystyrene content of 0.1-2.0 wt%, preferably 0.2-1.5 wt%, more preferably 0.3-1.2 wt%, as determined by IR; and / or

[0054] - a talc content of 0-1.5 wt%, preferably 0.01-1.0 wt%, more preferably 0.1-0.7 wt%, as determined by IR; and / or

[0055] - a polypropylene (iPP) content of 80-99 wt%, preferably 82-98 wt%, more preferably 84-96 wt%, determined by IR.

[0056] The mixed plastic polypropylene based blend is preferably a post-consumer recycled polypropylene based blend and / or a post-industrial recycled polypropylene based blend.

[0057] Preferably, based on the total weight of the original polypropylene composition, the content of the mixed plastic polypropylene-based blend in the original polypropylene composition is 25.0-99.999 wt%, preferably 29.0-99.995 wt%, more preferably 40.0-99.99 wt%, and even more preferably 50.0-99.9 wt%.

[0058] The original polypropylene composition may contain other polymer components, and the content of the other polymer components is 0-74.9 wt%, preferably 0-70.9 wt%, even more preferably 0-59.9 wt%, further more preferably 0-49.9 wt%, based on the total weight of the original polypropylene composition.

[0059] The other polymer component is preferably a polypropylene resin, such as a propylene homopolymer, a propylene random copolymer or a heterophasic propylene copolymer.

[0060] The other polymer component may be a virgin polymer component or a recycled polymer component derived from, for example, a post-consumer recycled polymer blend and / or a post-industrial recycled polymer blend. Preferably, the other polymer component is a virgin polymer component.

[0061] Other polymer components are usually added to the original polypropylene composition in order to adjust the properties of the original polypropylene composition for its subsequent use.

[0062] The original polypropylene composition is blended with a non-peroxide rheology control agent, preferably by compounding to obtain a polypropylene composition with controlled rheology.

[0063] Therefore, the non-peroxide rheology control agent is added to the original polypropylene composition in an amount of 0.001-5.0 wt%, more preferably 0.005-2.5 wt%, still more preferably 0.01-1.5 wt%, based on the total weight of the original polypropylene composition and the non-peroxide rheology control agent combination.

[0064] The non-peroxide rheology control agent is suitable for increasing the melt flow rate of the original polypropylene composition during compounding, preferably at elevated temperature, to obtain a controlled rheology polypropylene composition.

[0065] The non-peroxide rheology control agent preferably comprises at least two components (I) and (II).

[0066] Component (I) is preferably a piperazine ester derivative, such as a (1,2,2,6,6-pentaalkyl-4-piperidinyl) ester derivative, wherein the alkyl residues at positions 1, 2, 2, 6 and 6 are preferably independently selected from C1-C 12 Alkyl is more preferably selected from C1-C4 alkyl, such as methyl, ethyl, propyl, n-butyl, isobutyl or tert-butyl, still more preferably selected from methyl or ethyl. Most preferably, all alkyl residues in positions 1, 2, 2, 6 and 6 are methyl.

[0067] Particularly suitable as component (I) is bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, as shown in formula (I):

[0068]

[0069] Component (II) is preferably an aromatic carbonyl component, more preferably an aromatic dicarbonyl component, and still more preferably an aromatic diketone component.

[0070] Particularly suitable as component (II) is 1,4-diacetylbenzene, as shown in formula (II);

[0071]

[0072] The non-peroxide rheology control agent is preferably added to the original polypropylene composition in the form of a masterbatch, wherein at least two components are present in a polymer matrix.

[0073] In a preferred embodiment where the non-peroxide rheology control agent is added to the original polypropylene composition in the form of a masterbatch, the polymer compounds of the polymer matrix are accounted for by the non-peroxide rheology control agent.

[0074] In said embodiment, the amount of compounds (I) and (II) added to the original polypropylene composition is preferably 0.001-1.0 wt%, more preferably 0.005-0.5 wt%, still more preferably 0.01-0.3 wt%, based on the total weight of the original polypropylene composition.

[0075] Alternatively, the non-peroxide rheology control agent is added in its neat form to the original polypropylene composition.

[0076] Non-peroxide rheology control agents do not comprise peroxides, ie, do not contain peroxides, such as organic peroxides.

[0077] More preferably, the original polypropylene composition comprises no peroxide, ie contains no peroxide, such as organic peroxide.

[0078] The original polypropylene composition may further comprise additives, for example one or more additives selected from antioxidants, UV stabilizers, slip agents, nucleating agents, pigments, lubricants, masterbatch polymers and / or anti-fogging agents.

[0079] The additives are typically present in the composition in an amount of up to 4.0 wt.-%, such as 0.01 to 4.0 wt.-%, preferably 0.05 to 3.0 wt.-%, based on the total weight of the original polypropylene composition.

[0080] The melt flow rate MFR2 (230° C., 2.16 kg, ISO 1133) of the original polypropylene composition is typically 8.0 to 40 g / 10 min, preferably 9.0 to 35 g / 10 min, more preferably 10.0 to 30 g / 10 min.

[0081] The controlled rheology polypropylene composition is preferably obtained from a virgin polypropylene composition by compounding the virgin polypropylene composition with a non-peroxide rheology control agent and optional additives at a maximum temperature below 250°C, preferably 160-230°C, more preferably 200-220°C.

[0082] During the compounding step, the polymer components of the original polypropylene composition degrade, thereby reducing the melt viscosity of the compounded composition, which can be measured as an increased melt flow rate of the final controlled rheology polypropylene composition. The degradation rate can be controlled by, for example, controlling the amount of non-peroxide rheology control agent or controlling the compounding conditions (e.g., compounding temperature profile).

[0083] The controlled rheology polypropylene composition thus obtained has a melt flow rate MFR2 measured according to ISO 1133-1:2011 at 230°C and 2.16 kg of at least 10 g / 10 min, for example 10 to 250 g / 10 min, preferably 15 to 225 g / 10 min, more preferably 25 to 200 g / 10 min, still more preferably 40 to 175 g / 10 min, most preferably 65 to 150 g / 10 min.

[0084] The ratio of the melt flow rate MFR2(CR-PP) of the controlled rheology polypropylene composition to the melt flow rate MFR2(PP) of the virgin polypropylene composition is 1.5-30.0, preferably 1.7-25.0, more preferably 2.0-20.0.

[0085] The controlled rheology polypropylene composition is characterized by a specific pattern of degradation products, which can be analyzed as volatile organic compounds (VOC). VOC is defined as any organic compound with an initial boiling point less than or equal to 250°C measured at a standard atmospheric pressure of 101.3 kPa (EU VOC Solvent Emissions Directive 199 / 13 / EC) and is therefore easily analyzed by GC-MS.

[0086] Preferably, the controlled rheology polypropylene composition has a total volatile organic compound (VOC) content determined according to VDA 278 below 500 μg / g, such as 50-450 μg / g, more preferably 150-400 μg / g, still more preferably 200-350 μg / g.

[0087] In gas chromatography-mass spectrometry (GC-MS) analysis, volatile organic compounds can be analyzed by their GC-MS peaks varying with time. Thus, the controlled rheology polypropylene composition exhibits characteristically low volatile organic compound (VOC) emissions in the early time interval of 3.0-8.5 minutes.

[0088] The controlled rheology polypropylene composition has a volatile organic compound (VOC) emission within a time interval of 3.0-8.5 minutes measured by GC-MS of no more than 2.8 μg / g, for example 1.5-2.7 μg / g, preferably 1.7-2.6 μg / g, more preferably 2.0-2.5 μg / g.

[0089] Furthermore, the controlled rheology polypropylene composition preferably has a volatile organic compound (VOC) emission within a time interval of 3.0-4.0 minutes as determined by GC-MS of no more than 1.5 μg / g, such as 0.1-1.5 μg / g, more preferably 0.3-1.3 μg / g, still more preferably 0.5-1.0 μg / g.

[0090] Furthermore, the controlled rheology polypropylene composition preferably has a volatile organic compound (VOC) emission within a time interval of 16.5-21.5 minutes as determined by GC-MS of no more than 50.0 μg / g, such as 15.0-50.0 μg / g, more preferably 20.0-40.0 μg / g, still more preferably 22.5-30.0 μg / g.

[0091] Furthermore, the controlled rheology polypropylene composition preferably has a volatile organic compound (VOC) emission within a time interval of 32.0-34.5 minutes as determined by GC-MS of no more than 80.0 μg / g, such as 35.0-80.0 μg / g, more preferably 40.0-77.5 μg / g, still more preferably 50-76.0 μg / g.

[0092] The above-mentioned volatile organic compound (VOC) emissions are determined by GC-MS, preferably by GC-MS on a chromatographic column with a length of 50 m and / or a diameter of 0.32 mm and / or a layer thickness of 0.52 μm. The chromatographic column is preferably a fused silica column. Furthermore, the chromatographic column preferably comprises a non-polar, bonded, cross-linked material containing 5% phenyl polysiloxane and 95% methyl polysiloxane.

[0093] Preferably, GC-MS measurements are performed as follows: the carrier gas flow rate (preferably helium flow rate) is 2.0 mL / min and / or the furnace temperature is initially 40°C and maintained for 2 minutes, then at 3°C ​​min -1 The heating rate was raised to 92 °C and then to 5 °C min -1 The heating rate was increased to 160 °C and then to 10 °C min -1 The temperature was raised to a final temperature of 280° C. at a heating rate of 1000 ℃, and the final temperature was maintained for 10 minutes.

[0094] Volatile organic compounds (VOCs) can also be identified individually by GC-MS.

[0095] Therefore, preferably, the relative content of the compound selected from α-methylstyrene, acetophenone, 2-phenyl-2-propanol, 2-ethoxy-2-methylpropane, pentylene hydrate, 2-butanone, ethyl acetate and 2-[3-(2-hydropropan-2-yl)phenyl]2-propanol in the total content of volatile organic compounds (VOC) measured by GC-MS does not exceed 1.0%, for example, 0.01-1.0%, preferably 0.05-0.9%, more preferably 0.1-0.8%

[0096] These compounds, α-methylstyrene, acetophenone, 2-phenyl-2-propanol, 2-ethoxy-2-methylpropane, amylene hydrate, 2-butanone, ethyl acetate and 2-[3-(2-hydropropan-2-yl)phenyl]2-propanol, can be attributed to residual unreacted organic peroxides and peroxide decomposition products. Therefore, the low content of these compounds indicates that the degradation of the controlled rheology polypropylene composition is not caused by peroxides, especially organic peroxides.

[0097] On the contrary, the total content of volatile organic compounds (VOC) as determined by GC-MS preferably comprises a relative content of at least 5.0%, for example 5.0-20.0%, more preferably 10.0-18.5% of compounds selected from 1,3-diacetylbenzene, 1,4-diacetylbenzene, 1-[3-(1-hydroxy-1-methylethyl)phenyl]ethanone and 1-[3-(1-hydroxy-1-methylethyl)phenyl]ethanone.

[0098] The Young's modulus of the controlled rheology polypropylene composition is preferably at least 900 MPa, such as 900-1500 MPa, preferably 950-1400 MPa, more preferably 1000-1350 MPa.

[0099] Furthermore, the controlled rheology polypropylene composition preferably has a yield strength of at least 20 MPa, such as 20-40 MPa, more preferably 21-37 MPa, still more preferably 22-35 MPa.

[0100] Furthermore, the controlled rheology polypropylene composition preferably has a strain at break of at least 5.0%, such as 5.0-35%, more preferably 7.5-32%, still more preferably 9.0-30%.

[0101] Furthermore, the controlled rheology polypropylene composition preferably has a Charpy notched impact strength of at least 3.5 kJ / m measured at 23°C. 2 , for example 3.5-7.5 kJ / m 2 , more preferably 4.0-6.5 kJ / m 2 , and more preferably 4.5-6.0 kJ / m 2 .

[0102] In another aspect, the present invention relates to a method for producing the above or below controlled rheology polypropylene composition, comprising the following steps:

[0103] - Providing a polypropylene composition comprising a mixed plastic polypropylene-based blend;

[0104] - mixing the polypropylene composition with a non-peroxide rheology control agent;

[0105] - Compounding the polypropylene composition with a non-peroxide rheology control agent at a maximum temperature below 250°C, preferably 160-230°C, more preferably 200-220°C.

[0106] Accordingly, the polypropylene composition comprising the mixed plastic polypropylene-based blend preferably reflects all embodiments and properties of the original polypropylene composition as described above or below.

[0107] Furthermore, the non-peroxide rheology control agent preferably reflects all of the embodiments and characteristics described above or below for the non-peroxide rheology control agents.

[0108] Furthermore, the controlled rheology polypropylene composition preferably reflects all the embodiments and characteristics of the controlled rheology polypropylene composition described above or below.

[0109] The original polypropylene composition is preferably compounded with the non-peroxide rheology control agent and optional additives at a maximum temperature below 250°C, preferably 160-230°C, more preferably 200-220°C, preferably as described above or below.

[0110] The weight ratio of the original polypropylene composition to the non-peroxide rheology control agent is preferably 99.999:0.001-95.0:5.0, more preferably 99.995:0.005-97.5:2.5, still more preferably 99.99:0.01-98.5:1.5.

[0111] The compounding step is preferably carried out in an extruder. Preferred extruders are, for example, single-screw extruders, counter-rotating and co-rotating twin-screw extruders, planetary gear extruders, ring extruders or co-kneaders, etc. It is also possible to use extruders with at least one evacuable degassing chamber.

[0112] Suitable extruders and kneaders are described, for example, in “Handbuch der Kunststoffextrusion, Vol. 1 Grundlagen, ed. F. Hensen, W Knappe, H. Potente, 1989, pp. 3-7, ISBN: 3-446-14339-4 (Vol. 2 Extrusionanlagen 1986, ISBN 3-446-14329-7)”.

[0113] In another aspect, the present invention relates to an article comprising the controlled rheology polypropylene composition described above or below.

[0114] Therefore, the controlled rheology polypropylene composition preferably reflects all the embodiments and characteristics of the controlled rheology polypropylene composition described above or below.

[0115] The article is preferably an injection molded article, a nonwoven article (eg, a meltblown nonwoven article), or a film.

[0116] To make articles, the controlled rheology polypropylene composition may be melt blended with other polymer components, additives, pigments and / or fillers.

[0117] The other polymer component is preferably a polypropylene resin, such as a propylene homopolymer, a propylene random copolymer or a heterophasic propylene copolymer.

[0118] The other polymer component may be a virgin polymer component, or a recycled polymer component derived from, for example, a post-consumer recycled polymer blend and / or a post-industrial recycled polymer blend.

[0119] Polymer components are usually added to the original polypropylene composition in order to adjust the properties of the article.

[0120] Based on the total weight of the article, the content of the controlled rheology polypropylene composition in the article is preferably 25-100 wt%, more preferably 35-100 wt%, and even more preferably 50-100 wt%.

[0121] In a last aspect, the present invention relates to the use of a controlled rheology polypropylene composition as described above or below for the manufacture of an article comprising a mixed plastic polypropylene-based blend.

[0122] Therefore, the controlled rheology polypropylene composition, mixed plastic polypropylene-based blend and articles preferably reflect all the embodiments and characteristics of the controlled rheology polypropylene composition, mixed plastic polypropylene-based blend and articles described above or below.

[0123] Experimental Section

[0124] The present invention includes the following examples to demonstrate certain aspects and embodiments of the present invention described in the claims. However, it should be understood by those skilled in the art that the following description is illustrative only and should not be considered in any way as limiting the present invention.

[0125] 1. Test Method

[0126] CRYSTEX

[0127] Determination of the crystalline fraction (CF) and the soluble fraction (SF) and their respective characteristics (IV and ethylene content)

[0128] The crystalline fraction (CF) and soluble fraction (SF) of the polypropylene composition, as well as the comonomer content and intrinsic viscosity of each fraction, were analyzed using the CRYSTEX instrument from Polymer Char (Valencia, Spain). Detailed information on this technology 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)

[0129] The crystalline and amorphous fractions were separated by the following temperature cycle: dissolution at 160° C., crystallization at 40° C., and redissolution in 1,2,4-trichlorobenzene at 160° C. SF and CF were quantified by an integrated infrared detector (IR4) and the ethylene content (C2) was determined, and the intrinsic viscosity (iV) was determined using an online 2-capillary viscometer.

[0130] The IR4 detector is a multi-wavelength detector that measures two different wavelength bands (CH3 stretching vibration (centered at about 2960cm -1 ) and CH stretching vibration (2700-3000cm -1 ) is used to determine the concentration and ethylene content of ethylene-propylene copolymers. The IR4 detector is used with a series of 8 known ethylene contents ranging from 2 wt% to 69 wt% (by 13 C-NMR measurement) was calibrated with EP copolymers, each copolymer having a different concentration of 2-13 mg / ml. In order to simultaneously meet the two characteristics of the various polymer concentrations expected during Crystex analysis, i.e., concentration and ethylene content, the following calibration equation was applied:

[0131] Concentration = a + b * absorbance (CH) + c * (absorbance (CH)) 2 +d*absorbance(CH3)+e*(absorbance(CH3) 2 +f*absorbance(CH)*absorbance(CH3) (Formula 1)

[0132] CH3 / 1000C = a+b*absorbance(CH3)+c*absorbance(CH3)+d*(absorbance(CH3) / absorbance(CH3))+e*(absorbance(CH3) / absorbance(CH3)) 2 (Formula 2)

[0133] Constants a to e of Formula 1 and constants a to f of Formula 2 are determined by least squares regression analysis.

[0134] The CH3 / 1000C is converted to ethylene content (in wt%) using the following relationship:

[0135] wt.-% (ethylene in EP copolymer) = 100-CH3 / 1000TC*0.3 (Formula 3)

[0136] The amounts of the soluble fraction (SF) and the crystalline fraction (CF) are related by means of the XS calibration to the amounts of the "xylene cold soluble" (XCS) fraction and the "xylene cold insoluble" (XCI) fraction, respectively, determined by the standard gravimetric method according to ISO 16152. The XS calibration was achieved by testing a number of EP copolymers with an XS content in the range of 2-31 wt%. The determined XS calibration is linear:

[0137] wt%XCS=1.01*wt%SF (Formula 4)

[0138] The intrinsic viscosity (iV) of the polymer and its soluble and crystalline fractions was determined using an online 2-capillary viscometer and correlated to the corresponding iV determined by the standard method in decalin according to ISO 1628-3. Calibration was performed with various EP PP copolymers with iV = 2-4 dL / g. The calibration curve determined was linear:

[0139] iV(dL / g)=a*Vsp / c (Formula 5)

[0140] The samples to be analyzed were weighed at a concentration of 10-20 mg / ml. To avoid the injection of gels and / or polymers that may not dissolve in TCB at 160°C, such as PET and PA, the weighed samples were loaded into a stainless steel mesh with MW 0.077 / D 0.05 mm.

[0141] After automatically filling the vial with 1,2,4-TCB containing 250 mg / l 2,6-tert-butyl-4-methylphenol (BHT) as an antioxidant, the sample was dissolved at 160°C until completely dissolved, usually for 60 minutes, with continuous stirring at 400 rpm. To avoid sample degradation, the polymer solution was covered with a nitrogen atmosphere during the dissolution process.

[0142] A certain volume of sample solution is injected into a column filled with an inert carrier, where the sample is crystallized and the soluble fraction is separated from the crystalline part. 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 polymer blend. During the second injection, the soluble fraction (low temperature) and the crystalline fraction (high temperature) of the crystallization cycle are measured (wt.-% SF, wt.-% C2, iV), where wt.-% CF is calculated as follows:

[0143] wt.-%CF=100–wt.-%SF.

[0144] Determination of the amount of "iPP", "PVC", "PA", "PET", "PS", etc. by infrared spectroscopy transmission method Sample preparation:

[0145] All calibration samples and samples to be analyzed were prepared in a similar manner on fused press plates.

[0146] About 2-3 g of the compound to be analyzed are melted at 190°C. Then, a pressure of 60-80 bar is applied in a hydraulic heated press for 20 seconds. The sample is then cooled to room temperature in a cold press within 40 seconds under the same pressure to control the morphology of the compound. The thickness of the plate is controlled by a 2.5 cm × 2.5 cm metal calibration frame plate with a thickness of 100-200 μm (depending on the MFR of the sample); two plates are produced in parallel at the same time and under the same conditions. The thickness of each plate is measured before any FTIR measurement; all plates have a thickness of 100-200 μm.

[0147] In order to control the plate surface and avoid any disturbance during the measurement, all plates were pressed between two sheets of double-sided silicone release paper.

[0148] For powder samples or heterogeneous compounds, the pressing process was repeated three times to improve homogeneity by pressing and cutting the samples under the same conditions as above.

[0149] Spectrometer:

[0150] Use a standard transmission FTIR spectrometer, such as a Bruker Vertex 70 FTIR spectrometer, with the following settings:

[0151] - Spectral range 4000-400cm -1 ,

[0152] -Aperture is 6mm,

[0153] - Spectral resolution is 2cm -1 ,

[0154] -16 background scans, 16 spectral scans,

[0155] -The interference pattern is filled with zeros with a factor of 32

[0156] -Norton Beer High Cut Toe.

[0157] The spectra were recorded and analyzed by Bruker Opus software.

[0158] Calibration samples:

[0159] Since FTIR is an auxiliary method, several calibration standards are mixed to cover the target analysis range, typically:

[0160] -0.2-2.5wt% polyamide (PA)

[0161] -0.1-5wt% polystyrene (PS)

[0162] - 0.2-2.5 wt% polyethylene terephthalate (PET)

[0163] -0.1-4wt% polyvinyl chloride (PVC)

[0164] The following commercial materials were used in the compound: Borealis HC600TF as iPP, Borealis FB3450 as HDPE, and for the target polymer, RAMAPET N1S (Indorama Polymer) for PET, (BASF) for polyamide 6, Styrolution PS 486N (Ineos) for high-impact polystyrene (HIPS), and Inovyn PVC 263B (in powder form) for PVC.

[0165] All compounds were produced on a small scale in a Haake kneader at temperatures below 265°C and times less than 10 minutes to avoid degradation.

[0166] Antioxidants such as Irgafos 168 (3000ppm) are also added to minimize degradation.

[0167] calibration:

[0168] The FTIR calibration principle is the same for all components: the intensity of a specific FTIR spectral band is divided by the plate thickness and the intensity of the 1 H or 13 C solution NMR determination of the component content.

[0169] Each specific FTIR absorption band is chosen because: regardless of the composition of the calibration standards and actual samples, its intensity increases with increasing concentration of the component and is isolated from the rest of the peaks.

[0170] This method is described in the publication by Signoret et al. (“Alterations of plastic spectra in MIR and the potential impacts on identification towards recycling”, Resources, conservation and Recycling journal, 2020, Vol. 161, Article No. 104980).

[0171] The wavelength of each calibration band is:

[0172] -PA is 3300cm -1 ,

[0173] -PS is 1601cm -1 ,

[0174] -PET is 1410cm -1 ,

[0175] -PVC is 615cm -1 ,

[0176] -iPP is 1167cm -1 .

[0177] A linear calibration (linear relationship based on Beer-Lambert's law) is constructed for each polymer component i. A typical linear correlation for such a calibration is shown below:

[0178]

[0179] in

[0180] x i is the fraction of polymer component i (in wt%);

[0181] E i is the absorbance intensity of the specific band associated with polymer component i (in au). These specific bands are: PA is 3300 cm -1 , PS is 1601cm -1 PET is 1410cm -1 PVC is 615cm -1 , iPP is 1167cm -1 ;

[0182] d is the thickness of the sample plate;

[0183] A i and B i are the two correlation coefficients determined for each calibration curve.

[0184] The following bands are used to estimate the content of EVA, chalk and talc:

[0185] EVA: 607cm -1 The center band

[0186] Chalk: 1798cm -1 The center band

[0187] Talc: 3676cm -1 The center band

[0188] For each calibration standard (when available), the amount of each component is given by 1 H or 13 C solution state NMR determination, which is the primary method (except PA). The NMR measurements are performed on exactly the same FTIR plate used to construct the FTIR calibration curve.

[0189] Quantification of microstructure by NMR spectroscopy

[0190] Quantitative nuclear magnetic resonance (NMR) spectroscopy is used to quantify the ethylene content in the polymer.

[0191] Quantitative analysis was recorded in solution using a Bruker Avance III 400 NMR spectrometer. 13 C{ 1 H}NMR spectroscopy, spectrometer for 1 H and 13 C runs at 400.15 and 100.62 MHz respectively. 13 All spectra were recorded at 125°C using a C optimized 10 mm extended temperature probe head and nitrogen was used for all pneumatics. About 200 mg of the material was dissolved in about 3 ml of 1,2-tetrachloroethane-d2 (TCE-d2) along with about 3 mg of BHT (2,6-di-tert-butyl-4-methylphenol, CAS 128-37-0) and chromium (III) acetylacetonate (Cr(acac)3) to give a 60 mM relaxation agent solution in solvent as described in "G. Singh, A. Kothari, V. Gupta, Polymer Testing 2009, 28(5), 475".

[0192] To ensure that the solution is homogeneous, the NMR tube is further heated in a rotary furnace for at least 1 hour after preliminary sample preparation in a heating block. After the tube is inserted into the magnet, it is rotated at a speed of 10 Hz. This setting is selected mainly for the quantitative needs of high resolution and accurate quantification of ethylene content. Standard single pulse excitation without NOE is adopted, using optimized tip angle, 1 second cycle delay and double-stage WALTZ16 decoupling scheme, as described in "Z. Zhou, R. Kuemmerle, X. Qiu, D. Redwine, R. Cong, A. Taha, D. Baugh, B. Winniford, J. Mag. Reson. 187 (2007) 225 and V. Busico, P. Carbonniere, R. Cipullo, C. Pellecchia, J. Severn, G. Talarico, Macromol. Rapid Commun. 2007, 28, 1128". A total of 6144 (6k) transients are obtained for each spectrum.

[0193] Quantitative 13 C{ 1 The H} NMR spectra were processed and integrated, and the relevant quantitative properties were determined from the integration. All chemical shifts were indirectly referenced to the central methylene of the ethylene segment (EEE) at 30.00 ppm using the chemical shift of the solvent. Even if this structural unit is not present, the method can be referenced similarly.

[0194] A characteristic signal corresponding to the incorporation of ethylene was observed (as described in "Cheng, HN, Macromolecules 1984, 17, 1950") and the comonomer fraction was calculated as the fraction of ethylene in the polymer relative to all monomers in the polymer:

[0195] fE=(E / (P+E))

[0196] The comonomer fraction was calculated using the method of "WJ. Wang and S. Zhu, Macromolecules 2000, 33 1157" by 13 C{ 1 The quantification is performed by integrating multiple signals across the entire spectral region in the H} spectrum. Minor adjustments to the integration region increase applicability over the entire range of comonomer content.

[0197] Calculate the mole percentage of added comonomer from the mole fraction:

[0198] E[mol%]=100*fE

[0199] Calculate the weight percentage of added comonomer from the mole fraction:

[0200] E[wt%]=100*(fE*28.06) / ((fE*28.06)+((1-fE)*42.08))

[0201] Melt flow rate (MFR)

[0202] According to ISO 1133-1:2011 standard (Plastics - Determination of melt mass flow rate (MFR) and melt volume flow rate (MVR) of thermoplastics - Part 1: Standard method), MFR measurement was performed using a Zwick / Roell Mflow melt flow indexer (Zwick Roell, Germany) at 230°C and 2.16 kg. The piston was cut every 5 mm. The time between cuts was measured and each extrudate was weighed on an ABS220-4 electronic balance (Kern & Sohn, Germany). Extrapolated to 10 minutes, the MFR (in g / 10 min) for each cut was calculated. One measurement was performed for each material. In one measurement, 6 cuts were performed and used to calculate the average value.

[0203] Production of Multi-Purpose Specimens (MPS) and Charpy Type 1 Specimens

[0204] All MPS were produced by injection molding using an Engel Victory 60 (Engel, Austria) according to ISO 3167 (Plastics - Multipurpose test specimens) and ISO 19069-2 (Plastics - Polypropylene (PP) molding and extrusion materials - Part 2: Preparation of test specimens and determination of properties). The specimens were conditioned at 23 °C and 50% relative humidity for at least three days. After conditioning, these specimens were used for tensile tests. In addition, type 1 specimens for Charpy notched impact testing according to ISO 179-1 were produced by injection molding and subsequently notched after conditioning at 23 °C and 50% relative humidity for at least three days. The tests were performed after conditioning at 23 °C and 50% relative humidity for at least 16 hours.

[0205] Tensile properties

[0206] Mechanical properties (Young's modulus, yield strength and strain at break) were tested at 23°C using a Zwick AllroundLine Z020 universal testing machine (Zwick Roell, Germany) equipped with a multi-extensometer. Test parameters and MPS were used according to ISO 527-1:2012 (Plastics - Determination of tensile properties - Part 1: General principles) and ISO527-2:2012 standards (Part 2: Test conditions for molded and extruded plastics), with a moving speed of 1 mm / min for determination of Young's modulus until the strain was 0.25%, then 50 mm / min until failure. Five MPS were tested for each material to calculate the average value.

[0207] Charpy notched impact strength

[0208] Impact tests were performed using a Zwick / Roell HIT25P pendulum impact tester (Zwick Roell, Germany) according to ISO 179-1:2010 (Plastics - Determination of Charpy impact properties - Part 1: Non-instrumented impact test). After preliminary testing to determine the appropriate pendulum size, a 0.5 joule pendulum was used for all tests. The notch was made with a Leica RM2265 microtome (Leica, Germany) and measured with a Mitotoyo notch depth micrometer (Wels, Austria). The test conditions were 23°C and the notch radius of the edge notched specimen was 0.25 mm (1eA). Ten specimens of each material were tested to calculate the average value.

[0209] GC-MS analysis

[0210] The analyzed materials were compounded on the same day, stored in closed aluminum bottles for 3 days, and then pressed at 180°C into The pressed plates were stored in plastic bags at room temperature for 5 days. Two samples of 4 mm × 30 mm size were punched out of the previously pressed plates for each material.

[0211] The qualitative and (semi) quantitative determination of volatile organic compounds (VOC) was carried out according to the method based on VDA 278. The determination was carried out using a PerkinElmer Clarus 690SQ 8 gas chromatograph-mass spectrometer (GC-MS), equipped with a PerkinElmer TurboMatrix 650 automatic thermal desorption device (ATD). The separation of VOC was carried out using a non-polar HP Ultra2 (Agilent Technologies, USA), and the helium (He) flow rate and temperature scheme are shown in Table 1. According to VDA 278, VOC was thermally desorbed at 90°C for 30 minutes.

[0212] Qualitative evaluation was performed using TurboMass software 6.1.2.2024 (including NIST / EPA / NIH mass spectral library 2.2). For (semi-)quantitative results, 0.5 mg mL in methanol was used before the determination. -1 A single-point calibration was performed with a toluene standard solution. To be able to measure the calibration solution, 4 μL of the solution was loaded into the packed column injector via an autosampler, which was connected to a sample tube filled with Tenax TA. The injector was heated to 430 °C and the flow rate was 20 mL min -1 The sample was purged with a helium flow rate of 100 μL for 30 minutes. In addition, a blank test was performed with 4 μL of methanol (VWR Chemicals, USA). According to VDA 278, the calibration standard was thermally desorbed at 280 °C for 30 minutes. In addition, a blank test was performed on an empty sample tube before each material analysis. The sample was measured twice. The highest value of the two samples measured represents the VOC value (in μg g -1 sample).

[0213] As described above, the VOC emission values ​​were determined by external single-point calibration using a toluene standard solution. The mass of toluene loaded into the Tenax TA packed sample tube, m std The ratio of (μg) to the corresponding peak area gives the so-called response factor Rf (see formula below).

[0214]

[0215] This factor is then multiplied by the sample peak area and the sample mass m s The quotient of (unit: mg) gives the value of semi-quantitative VOC emissions (unit: μg / g).

[0216]

[0217] This assessment can be applied to the entire chromatogram obtained from a given GC-MS measurement to obtain the total VOC content, or to parts thereof, i.e. specific time intervals in a given chromatogram. The latter gives semi-quantitative VOC emission values ​​associated with a single peak or a group of peaks (i.e. a single substance or a group of substances) within a specific time interval of the corresponding chromatogram. It should be noted that in the context of this patent, the terms "VOC content" and "VOC emissions" are used interchangeably.

[0218] Table 1: ATD and GC-MS parameters

[0219]

[0220] 2. Materials

[0221] Blend A: The properties of the mixed plastic polypropylene-based blends (Blend A) used for evaluation are shown in Table 1. Since these blends are derived from a mechanical recycling process, the properties are presented as ranges.

[0222] Table 2: Properties of mixed plastic polypropylene-based blends (Blend A)

[0223]

[0224]

[0225] PP B is a native heterophasic propylene copolymer with a melt flow rate MFR2 (230°C, 2.16 kg, ISO 1133) of 0.25 g / 10 min, a flexural modulus (ISO 178) of 2000 MPa and a Charpy notched impact strength (23°C, ISO 179-1) of 30 kJ / m 2 , commercially available from Borealis AG.

[0226] PP C is a native heterophasic propylene copolymer with a melt flow rate MFR2 (230°C, 2.16 kg, ISO 1133) of 100 g / 10 min, a flexural modulus (ISO 178) of 1500 MPa and a Charpy notched impact strength (23°C, ISO 179-1) of 4 kJ / m 2 , commercially available from Borealis AG.

[0227] PP D is a native heterophasic propylene copolymer with a melt flow rate MFR2 (230°C, 2.16 kg, ISO 1133) of 35 g / 10 min, a flexural modulus (ISO 178) of 1600 MPa and a Charpy notched impact strength (23°C, ISO 179-1) of 6.5 kJ / m 2 , commercially available from Borealis AG.

[0228] The rheology control agent RCA 1 is a non-peroxide rheology control agent comprising bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate and 1,4-diacetylbenzene in a polymer matrix. The commercial product may be GRAFTALEN MB EB-150H05 from Lehmann & Voss & Co. KG.

[0229] Rheology control agent RCA 2 is 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane, 20% on polypropylene, commercially available as Nouryon 301-20PP.

[0230] The rheology control agent RCA 3 is a rheology control agent containing peroxide in a polymer matrix, and a commercially available product may be GRAFTALEN MB EB-150DC10 from Lehmann & Voss & Co. KG.

[0231] The rheology control agent RCA 4 is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane in a polymer matrix, and a commercial product thereof may be Trigonox 101-20PP from Nouryon.

[0232] The rheology control agent RCA 5 is a peroxide masterbatch, and a commercially available product may be Polyvel CR5P from Polyvel Inc.

[0233] 3.Blending conditions

[0234] In producing the controlled rheology polypropylene compositions of inventive examples IE1 to IE8 and comparative examples CE1 to CE4, the following compounding conditions were used. Reference example RE1 reflects 100 wt% of blend A compounded using the same conditions:

[0235] Extruder: Twin-screw co-rotating extruder Leistritz ZSE 18MAXX

[0236] Screw speed: 600U / min

[0237] Output: 10kg / h

[0238] Region 1 30℃ Area 2 170℃ Area 3 200℃ Region 4 205℃ Area 5 210℃ Area 6 220℃ Area 7 210℃ Area 8 210℃ Area 9 210℃ Region 10 210℃ Area 11 210℃ Area 12 210℃ stop 210℃

[0239] The compositions of Examples IE1 to IE8 are shown in Table 3, and the compositions of CE1 to CE4 and RE1 are shown in Table 4.

[0240] Table 3: Composition of Examples IE1 to IE8

[0241] IE1 IE2 IE3 IE4 IE5 IE6 IE7 IE8 Blend A [wt%] 99.45 99.00 55.00 55.00 55.00 55.00 55.00 55.00 PP B [wt%] - - 44.50 44.00 43.00 - - - PP C [wt%] - - - - - - - 44.50 PP D [wt%] - - - - - 44.50 44.00 - RCA 1[wt%] 0.55 1.00 0.50 1.00 2.00 0.50 1.00 0.50 RCA 2 [wt%] - - - - - - - - RCA 3[wt%] - - - - - - - - RCA 4 [wt%] - - - - - - - - RCA 5 [wt%] - - - - - - - -

[0242] Table 4: Composition of CE1 to CE4 and RE1

[0243]

[0244]

[0245] 4. Properties of the Controlled Rheology Polypropylene Compositions in Examples

[0246] GC-MS was performed on Inventive Example IE1, Reference Example RE1, and Comparative Examples CE1 to CE4. The total VOC content and VOC emissions within a specific GC-MS time interval were measured. In addition, the amount of specific VOC components was determined from the GC-MS data, and the melt flow rate was determined.

[0247] Table 5 lists the VOC data and MFR2 values, Table 6 lists the total amounts of different VOC components, and Table 7 lists the relative amounts of different VOC components.

[0248] Table 5: MFR2 values, total VOC emissions and VOC emissions measured at specific selected time intervals in GC-MS.

[0249]

[0250] nm = not measurable, i.e. below the limit of detection and / or below the limit of quantification

[0251] Table 6: Total amount of individual VOC components obtained by GC-MS (in μg / g)

[0252]

[0253]

[0254] nm = not measurable, i.e. below the limit of detection and / or below the limit of quantification

[0255] Table 7: Relative amounts of individual VOC components as a percentage of the total VOC content derived from GC-MS

[0256] RE1 IE1 CE1 CE4 α-Methylstyrene nm nm 4.0 nm Acetophenone nm 0.6 27.3 0.4 2-Phenyl-2-propanol nm nm 8.1 nm 2-Ethoxy-2-methylpropane nm nm nm nm Amylene hydrate nm nm nm nm 2-Butanone nm nm nm nm Ethyl acetate nm nm nm nm 2-[3-(2-Hydroxypropyl-2-yl)phenyl]2-propanol nm 0.2 nm 0.8 1,3-Diacetylbenzene nm 6.0 0.2 12.9 1,4-Diacetylbenzene nm 5.0 0.2 nm 1-[3-(1-Hydroxy-1-methylethyl)phenyl]-ethanone nm 3.4 nm 8.1 1-[4-(1-Hydroxy-1-methylethyl)phenyl]-ethanone 3.2 nm nm

[0257] nm = not measurable, i.e. below the limit of detection and / or below the limit of quantification

[0258] Tables 7 and 8 show that the controlled rheology polypropylene composition of Example IE1 of the present invention shows only a small amount of volatile organic compounds, such as α-methylstyrene, acetophenone, 2-phenyl-2-propanol, 2-ethoxy-2-methylpropane, pentylene hydrate, 2-butanone, ethyl acetate and 2-[3-(2-hydropropan-2-yl)phenyl]2-propanol, which can be attributed to residual unreacted organic peroxides and peroxide decomposition products. Only a small amount of acetophenone was detected.

[0259] Table 8 lists the additionally measured mechanical properties of inventive examples IE2 to IE8, reference example RE1 and comparative example CE1.

[0260] Table 8: Mechanical properties of Examples IE2 to IE8, RE1 and CE2

[0261] RE1 CE2 IE2 IE3 IE4 IE5 IE6 IE7 IE8 <![CDATA[MFR2[g / 10min]]]> 13.8 68 120 19 48 143 70 120 113 <![CDATA[Charpy NIS [kJ / m 2 > 6.2 5.2 4.8 5.4 5.0 4.7 5.9 5.0 4.9 Young's modulus [MPa] 1170 1240 1080 1180 1140 1090 1110 1060 1060 Yield strength [MPa] 27.2 25.4 23.6 28.2 27.4 27.0 26.0 24.9 25.3 Fracture strain [%] 46.5 10 9.7 20.2 11.8 11.9 13.9 7.6 10.6

[0262] The controlled rheology polypropylene compositions of the inventive examples IE1-IE8 show an improved balance of properties in terms of high melt flow rate, good impact properties and good mechanical properties. Comparing IE2 with RE1 and CE2, it can be seen that the addition of a non-peroxide rheology control agent to IE2 increases the melt flow rate to a greater extent than the addition of the same amount of a peroxide rheology control agent to CE2. As a result, the impact properties and mechanical properties are only compromised to a lesser extent by degradation.

[0263] From IE3 to IE8, it can be seen that the impact properties and mechanical properties can be adjusted by adding virgin polypropylene resin to the original polypropylene composition.

Claims

1. A controlled rheology polypropylene composition (CR-PP) derived from a polypropylene composition (PP) comprising a mixed plastic polypropylene-based blend, wherein: The controlled rheology polypropylene composition has: a melt flow rate MFR2 measured at 230°C and 2.16 kg according to ISO 1133-1:2011 of at least 10 g / 10 min, such as 10-250 g / 10 min, preferably 15-225 g / 10 min, more preferably 25-200 g / 10 min, still more preferably 40-175 g / 10 min, most preferably 65-150 g / 10 min, wherein the ratio of the melt flow rate MFR2(CR-PP) of the controlled rheology polypropylene composition to the melt flow rate MFR2(PP) of the virgin polypropylene composition is 1.5-30.0; and The volatile organic compound (VOC) emission within a time interval of 3.0-8.5 minutes determined by GC-MS does not exceed 2.8 μg / g, for example, 1.5-2.7 μg / g, preferably 1.7-2.6 μg / g, more preferably 2.0-2.5 μg / g.

2. The controlled rheology polypropylene composition according to claim 1, wherein: The controlled rheology polypropylene composition has: The volatile organic compound (VOC) emission measured by GC-MS within a time interval of 3.0-4.0 minutes does not exceed 1.5 μg / g, for example 0.1-1.5 μg / g, preferably 0.3-1.3 μg / g, more preferably 0.5-1.0 μg / g; and / or The volatile organic compound (VOC) emission measured by GC-MS within a time interval of 16.5-21.5 minutes does not exceed 50.0 μg / g, for example 15.0-50.0 μg / g, preferably 20.0-40.0 μg / g, more preferably 22.5-30.0 μg / g; and / or The volatile organic compound (VOC) emission within a time interval of 32.0-34.5 minutes determined by GC-MS does not exceed 80.0 μg / g, for example, 35.0-80.0 μg / g, preferably 40.0-77.5 μg / g, more preferably 50-76.0 μg / g.

3. The controlled rheology polypropylene composition according to claim 1 or 2, wherein: As determined by GC-MS, the relative content of the compound selected from α-methylstyrene, acetophenone, 2-phenyl-2-propanol, 2-ethoxy-2-methylpropane, pentene hydrate, 2-butanone, ethyl acetate and 2-[3-(2-hydropropan-2-yl)phenyl]2-propanol in the total content of volatile organic compounds (VOC) does not exceed 1.0%, for example, 0.01-1.0%, preferably 0.05-0.9%, and more preferably 0.1-0.8%.

4. The controlled rheology polypropylene composition according to any one of the preceding claims, wherein The controlled rheology polypropylene composition has a total volatile organic compound (VOC) content of less than 500 μg / g, such as 50-450 μg / g, preferably 150-400 μg / g, more preferably 200-350 μg / g, as measured according to VDA 278.

5. The controlled rheology polypropylene composition according to any one of the preceding claims, wherein The controlled rheology polypropylene composition has: - a Young's modulus of at least 900 MPa, for example 900-1500 MPa, preferably 950-1400 MPa, more preferably 1000-1350 MPa, measured according to ISO 527-1, -2:2012 on multipurpose injection moulded test specimens prepared according to ISO 3167 and ISO 19069-2; and / or - a yield strength of at least 20 MPa, such as 20-40 MPa, preferably 21-37 MPa, more preferably 22-35 MPa, measured according to ISO 527-1, -2:2012 on multipurpose injection moulded test specimens prepared according to ISO 3167 and ISO 19069-2; and / or - a strain at break of at least 5.0%, for example 5.0-35%, preferably 7.5-32%, more preferably 9.0-30%, measured according to ISO 527-1, -2:2012 on multipurpose injection moulded test specimens prepared according to ISO 3167 and ISO 19069-2; and / or - Charpy notched impact strength of at least 3.5 kJ / m at 23°C measured according to ISO 179-1:2010 on multipurpose injection moulded test specimens prepared according to ISO 3167 and ISO 19069-2 2 , for example 3.5-7.5 kJ / m 2 , preferably 4.0-6.5 kJ / m 2 , more preferably 4.5-6.0 kJ / m 2 .

6. The controlled rheology polypropylene composition according to any one of the preceding claims, wherein The mixed plastic polypropylene-based blend is a post-consumer recycled polypropylene-based blend and / or a post-industrial recycled polypropylene-based blend.

7. The controlled rheology polypropylene composition according to any one of the preceding claims, wherein Based on the total weight of the original polypropylene composition, the content of the mixed plastic polypropylene-based blend in the original polypropylene composition is 25.0-99.999wt%, preferably 29.0-99.995wt%, more preferably 40.0-99.99wt%, and even more preferably 50.0-99.9wt%.

8. The controlled rheology polypropylene composition according to any one of the preceding claims, wherein The ratio of the melt flow rate MFR2(CR-PP) of the controlled rheology polypropylene composition to the melt flow rate MFR2(PP) of the original polypropylene composition is 1.7-25.0, preferably 2.0-20.

0.

9. The controlled rheology polypropylene composition according to any one of the preceding claims, wherein The controlled rheology polypropylene composition can be obtained by compounding a raw polypropylene composition with a non-peroxide rheology control agent at a maximum temperature below 250°C, preferably 160-230°C, more preferably 200-220°C.

10. The controlled rheology polypropylene composition according to claim 9, wherein: The non-peroxide rheology control agent comprises at least two components (I) and (II), component (I) is a piperazine ester derivative, such as a (1,2,2,6,6-pentaalkyl-4-piperidinyl) ester derivative, wherein the alkyl residues at positions 1, 2, 2, 6 and 6 are preferably independently selected from C1-C12 alkyl, more preferably selected from C1-C4 alkyl, such as methyl, ethyl, propyl, n-butyl, isobutyl or tert-butyl, still more preferably selected from methyl or ethyl, and most preferably have the formula (I) as well as Component (II) is an aromatic carbonyl component, more preferably an aromatic dicarbonyl component, still more preferably an aromatic diketone component, and most preferably has the formula (II): Preferably, the non-peroxide rheology control agent is added in the form of a masterbatch wherein at least two components are present in a polymer matrix.

11. A method for producing a controlled rheology polypropylene composition according to any one of the preceding claims, comprising the steps of: - Providing a polypropylene composition comprising a mixed plastic polypropylene-based blend; - mixing the polypropylene composition with a non-peroxide rheology control agent; - Compounding the polypropylene composition with the non-peroxide rheology control agent at a maximum temperature below 250°C, preferably 160-230°C, more preferably 200-220°C.

12. The method according to claim 11, wherein: The weight ratio of the original polypropylene composition to the non-peroxide rheology control agent is 99.999:0.001-95.0:5.0, preferably 99.995:0.005-97.5:2.5, and more preferably 99.99:0.01-98.5:1.

5.

13. An article comprising the controlled rheology polypropylene composition of any one of the preceding claims.

14. Use of the controlled rheology polypropylene composition according to any one of claims 1 to 10 for the manufacture of articles comprising mixed plastic polypropylene-based blends.

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