Polyolefin composition comprising polyethylene and recycled plastic material

Abstract

The present invention relates to a polyolefin composition comprising: a) 20% to 65% by weight (based on the total weight of the polyolefin composition) of at least one high density polyethylene comprising at least one polyethylene homopolymer and at least one polyethylene copolymer, said at least one high density polyethylene having a melt flow rate MFR5 (190 DEG C, 5 kg, measured according to ISO 1133) of at least 0.8 g / 10 minutes and a B10ESCR (measured according to ASTM D1693) of more than 600 hours; b) from 35% to 80% by weight (based on the total weight of the polyolefin composition) of a polyethylene-rich blend of recycled plastic material, the polyethylene-rich blend of recycled plastic material being recycled from waste plastic material derived from post-consumer waste and / or post-industrial waste, wherein the amount of the C2 fraction as measured by NMR of the d2-tetrachloroethylene soluble fraction is 96.5 wt% or more, in particular in the range of 96.5 wt% to 99.9 wt%, and the amount of the continuous C3 fraction as measured by NMR of the d2-tetrachloroethylene soluble fraction is < = 3.5 wt%, in particular in the range of 0.1 wt% to 3.5 wt%; c) optionally further additives wherein the sum of all the ingredients is always 100% by weight, and wherein the polyolefin composition has an impact strength (ISO 179-1, Charpy 1 eA + 23 DEG C) of at least 25 kJ / m2.

Description

[0001] The present invention relates to a polyolefin composition comprising at least one bimodal polyethylene and a recycled plastic material, to an article comprising said polyolefin composition, and to a method for preparing such a polyolefin composition.

[0002] Description

[0003] Polyolefins, especially polyethylene and polypropylene, are increasingly being consumed in large quantities in a wide range of applications, including packaging for food and other items, fibers, automotive components, and a wide variety of manufactured goods. Given the large amount of waste collected compared to the amount of waste recycled back into the stream, there is still great potential for the intelligent reuse of plastic waste streams and the mechanical recycling of plastic waste.

[0004] By virtue of its inherent versatility, plastic plays a crucial role in a sustainable and resource-saving economy. However, with more and more plastics being manufactured and used in a linear economy model, plastic waste is now considered a serious social problem. To this end, it is important to form a circular economy that gives plastic waste a second life (i.e., recycle it). This not only avoids leaving plastic waste in the environment but also restores its value.

[0005] The European Commission confirmed in 2017 that it would focus on plastic production and use. According to the Packaging and Packaging Waste Directive (revised in 2018), the EU aims: 1) by 2025, at least 50% of all plastic packaging in the EU should be recycled, and 2) by 2030, all plastic packaging placed on the EU market should be reusable or easily recyclable. This has prompted brand owners and plastic processors to seek solutions with recycled materials or virgin / recycled blends. As of January 1, 2021, the EU imposed a new tax on non-recycled plastic packaging, calculated at €0.80 / kg based on the weight of non-recycled plastic packaging.

[0006] Therefore, there is an urgent need to find ways to recycle plastic waste. However, due to degradation, contamination, and the mixing of different plastics, recycled plastics are generally inferior in quality to virgin plastics.

[0007] A major trend in the polyolefin field is the use of recycled materials from a variety of sources. Durable goods streams, such as those from yellow bags, yellow bins, community collections, waste electrical equipment (WEE), or end-of-life vehicles (ELV), contain a variety of plastics. These materials can be processed to recover acrylonitrile-butadiene-styrene (ABS), high impact polystyrene (HIPS), polypropylene (PP), and polyethylene (PE) plastics. Separation can be carried out by density separation in water, followed by further separation based on fluorescence, near-infrared absorption, or Raman fluorescence.

[0008] Among plastic wastes, polyethylene is one of the most abundant because of its wide use in the packaging, construction, and pipe industries. Recycled polyethylene is mainly made from items such as bottles and packaging, which are sorted, shredded, washed, and homogenized to provide materials for different applications. Although recycled polyethylene has been used in low-pressure pipes for gardening and agriculture, other applications such as high-pressure pipes are more restricted due to higher requirements.

[0009] Different methods for useful applications of recycled polyethylene have been described.

[0010] WO 2021 / 074785 A1 describes a polyethylene blend comprising: 1 wt% to 50 wt% of recycled polyethylene; and 50 wt% to 99 wt% of a bimodal polyethylene composition. The bimodal polyethylene composition is composed of at least two ethylene copolymer components (a first ethylene copolymer and a second ethylene copolymer).

[0011] WO2021 / 74698A1 relates to a blow-molded article containing post-consumer recycled materials. The article can contain a blended ethylene-based polymer composition having a post-consumer resin (PCR) content ranging from greater than 10 wt% to less than 95 wt% and a virgin resin content ranging from greater than 5 wt% to less than 90 wt%, where the virgin resin is selected from HDPE, LLDPE, LDPE, EVA, or combinations thereof. The PCR is preferably HDPE PCR obtained from blow-molded articles such as lubricant bottles. Generally, although there may be recycling process impurities and the material source may include LLDPE and / or LDPE, such PCR may have a large amount of HDPE. Thus, the PCR may be a mixture of polyethylene (but usually mainly HDPE).

[0012] WO2021 / 074140A1 relates to a polyethylene composition, which comprises: polyethylene, preferably ≥95.0% by weight of polyethylene; and also comprises 100 ppm to 500 ppm of a phenolic antioxidant; 500 ppm to 2500 ppm of an organic phosphite stabilizer; and 500 ppm to 2500 ppm of a metal stearate, based on the total weight of the polyethylene composition.

[0013] As can be seen, it is generally possible to use recycled polyethylene instead of virgin polyethylene. However, when replacing virgin polymers with recycled materials, it is still necessary to improve or maintain thermomechanical properties such as impact strength or environmental stress crack resistance (ESCR).

[0014] Therefore, the object of the present invention is to provide a polyolefin composition in which at least a part of the virgin polyolefin is replaced by a polyolefin material recovered from waste plastic materials, while the thermomechanical properties of such a polyolefin composition are at least maintained or even improved.

[0015] This object has been solved by providing such a polyolefin composition, which comprises:

[0016] a) 20% to 65% by weight (based on the total weight of the polyolefin composition) of at least one high-density polyethylene comprising at least one polyethylene homopolymer and at least one polyethylene copolymer, said at least one high-density polyethylene having a melt flow rate MFR5 (190 °C, 5 kg, measured according to ISO 1133) of at least 0.8 g / 10 min and a B10 ESCR (measured according to ASTM D1693 at 50 °C in 10% Igepal under condition B) of more than 600 hours;

[0017] b) 35% to 80% by weight (based on the total weight of the polyolefin composition) of a polyethylene-rich blend of recycled plastic materials, said polyethylene-rich blend of recycled plastic materials being recovered from waste plastic materials derived from post-consumer waste and / or post-industrial waste, wherein:

[0018] - the amount of the C2 fraction, as measured by NMR of the d2-tetrachloroethylene soluble fraction, is more than 96.5% by weight, particularly in the range of 96.5% to 99.9% by weight, and

[0019] - the amount of the continuous C3 fraction, as measured by NMR of the d2-tetrachloroethylene soluble fraction, is ≤3.5% by weight, particularly in the range of 0.1% to 3.5% by weight;

[0020] c) Optional additional additives, where the sum of all components always adds up to 100% by weight.

[0021] where the impact strength of the polyolefin composition (ISO 179-1, Charpy 1eA + 23 °C) is at least 25 kJ / m 2 .

[0022] Accordingly, there is provided a polyolefin composition comprising recycled plastic material and virgin high-density polyethylene polymers, especially bimodal polyethylene polymers, comprising polyethylene homopolymers and polyethylene copolymers having a low melt flow rate and high environmental stress crack resistance (ESCR). The combination provides a composition in which at least a portion of the virgin polymer is replaced by recycled material having properties such as impact strength and melt flow rate and environmental stress crack resistance (ESCR) that are nearly equivalent to those of the virgin polymer. Such compositions are suitable for bottles and containers.

[0023] In the context of the specification, the term "C2 fraction" represents the total amount of ethylene units in the polyethylene-rich blend of recycled plastic material determined by NMR in the d2-tetrachloroethylene soluble fraction.

[0024] The term "continuous C3 fraction" represents the total amount of continuous units having 3 carbon atoms (continuous C3 units) corresponding to polypropylene.

[0025] As described, the polyolefin composition according to the invention comprises a polyethylene-rich blend of recycled plastic material having a high C2 content and a low iPP fraction (i.e., a low continuous C3 content). It has unexpectedly been found that at high recycle contents (≥ 35%), the purity of the polyethylene recycle has a significant effect on the impact strength of the polyolefin composition. Polyolefin compositions prepared with high-purity PE recycle have significantly higher impact strength than composites prepared from lower-purity PE recycle, even though the difference in impact strength between these recycles is not obvious.

[0026] It is to be understood that the polyolefin compositions of the present invention do not contain talc (except for any amounts present in the recycle) and rubber.

[0027] For the purposes of this specification and the appended claims, the term "recycled" is used to indicate that the material is recovered from post-consumer waste and / or industrial waste. That is, post-consumer waste refers to an object that has completed at least a first use cycle (or life cycle), i.e., has reached its first purpose and has passed through the hands of a consumer; while industrial waste refers to manufacturing waste that generally does not reach the consumer.

[0028] As further described below, typical other components derived from the first use are thermoplastic polymers (such as polystyrene and polyamide), talc, chalk, carbon black, pigments (such as TiO2), ink, wood, paper, cellulose, limonene, and fatty acids. The contents of polystyrene (PS) and polyamide (PA) in the recycled polymer can be determined by Fourier Transform Infrared Spectroscopy (FTIR), and the contents of talc, chalk, and carbon black can be measured by Thermogravimetric Analysis (TGA).

[0029] The term "virgin" refers to newly produced materials and / or objects that have not been recycled and are before the first use. In the case where the source of the polymer is not explicitly mentioned, the polymer is a "virgin" polymer.

[0030] According to one embodiment, the polyolefin composition of the present invention comprises:

[0031] a) 30 wt% to 60 wt%, preferably 35 wt% to 55 wt%, more preferably 40 wt% to 50 wt% (based on the total weight of the polyolefin composition) of at least one high-density polyethylene having a melt flow rate MFR5 (190 °C, 5 kg, measured according to ISO 1133) of at least 0.8 g / 10 min and a B10 ESCR (measured at 50 °C in 10% Igepal under condition B according to ASTM D1693) of more than 600 hours;

[0032] b) 40 wt% to 70 wt%, preferably 45 wt% to 65 wt%, more preferably 50 wt% to 60 wt% (based on the total weight of the polyolefin composition) of a polyethylene-rich blend of recycled plastic materials recovered from post-consumer waste and / or post-industrial waste, and

[0033] c) Optionally, additional additives, wherein the sum of all components always adds up to 100 wt%.

[0034] It should be understood that in the polymer composition, the amounts of virgin high-density polyethylene and polyethylene recyclate are always complementary to each other. For example, in one embodiment, the polymer composition may comprise 20 wt% virgin high-density polyethylene and 80 wt% polyethylene recyclate or vice versa, or comprise 30 wt% virgin high-density polyethylene and 70 wt% polyethylene recyclate or vice versa. It should be understood that there may be additives. In such a case, the amounts of virgin polyethylene and polyethylene recyclate may be slightly less, but the weight ratio still basically corresponds to the weight% as indicated.

[0035] In a preferred embodiment, the polyolefin composition of the present invention may comprise:

[0036] - 20% by weight of virgin high density polyethylene and 80% by weight of polyethylene recyclate;

[0037] - 30% by weight of virgin high density polyethylene and 70% by weight of polyethylene recyclate;

[0038] - 35% by weight of virgin high density polyethylene and 65% by weight of polyethylene recyclate;

[0039] - 40% by weight of virgin high density polyethylene and 60% by weight of polyethylene recyclate;

[0040] - 45% by weight of virgin high density polyethylene and 55% by weight of polyethylene recyclate;

[0041] - 50% by weight of virgin high density polyethylene and 50% by weight of polyethylene recyclate;

[0042] - 55% by weight of virgin high density polyethylene and 45% by weight of polyethylene recyclate;

[0043] - 60% by weight of virgin high density polyethylene and 40% by weight of polyethylene recyclate;

[0044] - 65% by weight of virgin high density polyethylene and 35% by weight of polyethylene recyclate.

[0045] In a preferred embodiment, the polyolefin composition comprises at least one stabilizer, in particular at least one antioxidant. The at least one stabilizer may be present in the polyolefin composition in an amount of 0.05% to 0.5% by weight, preferably 0.08% to 0.4% by weight, more preferably 0.10% to 0.3% by weight (based on the total weight of the polymer composition). In any case, the amount of the stabilizer, in particular the stabilizer in the form of an antioxidant, is greater than 500 ppm, preferably greater than 800 ppm, more preferably greater than 1000 ppm, for example 1500 ppm.

[0046] In a preferred embodiment, the impact strength of the polyolefin composition (ISO179-1, Charpy 1eA + 23 °C) is at least 30 kJ / m 2 , preferably at least 33 kJ / m 2 , more preferably at least 35 kJ / m 2 , still more preferably at least 38 kJ / m 2 , particularly in the range of 25 kJ / m 2 to 50 kJ / m 2 , more particularly in the range of 30 kJ / m 2 to 40 kJ / m2 in the range of, and even more particularly in the range of 33 kJ / m 2 to 39 kJ / m 2 .

[0047] In the case of a polyolefin composition comprising 50% to 55% by weight of polyethylene recyclate, the impact strength is in the range of 30 kJ / m 2 to 40 kJ / m 2 , and more particularly in the range of 33 kJ / m 2 to 38 kJ / m 2 .

[0048] The melt flow rate MFR5 (5 kg, 190 °C, measured according to ISO 1133) of the polyolefin composition is at least 0.8 g / 10 min, preferably at least 0.85 g / 10 min, more preferably at least 0.9 g / 10 min, particularly in the range of 0.8 g / 10 min to 2.0 g / 10 min, preferably 0.85 g / 10 min to 1.5 g / 10 min, more preferably 0.9 g / 10 min to 1.2 g / 10 min.

[0049] The melt flow rate MFR2 (2.16 kg, 190 °C, measured according to ISO 1133) of the polyolefin composition is at least 0.1 g / 10 min, preferably at least 0.15 g / 10 min, more preferably at least 0.2 g / 10 min, particularly in the range of 0.1 g / 10 min to 0.8 g / 10 min, preferably 0.15 g / 10 min to 0.5 g / 10 min, more preferably 0.2 g / 10 min to 0.3 g / 10 min.

[0050] In another embodiment, the polyolefin composition of the present invention has a Young's modulus of 800 MPa to 950 MPa, preferably 850 MPa to 900 MPa, more preferably 870 MPa to 880 MPa; a yield strength of 20 MPa to 30 MPa, preferably 23 MPa to 26 MPa; and a fracture strain of 50% to 110%, preferably 60% to 105%, such as 60% or 103%.

[0051] Virgin polyethylene polymer

[0052] The polyolefin composition of the present invention comprises 20% to 65% by weight, preferably 30% to 60% by weight, more preferably 35% to 55% by weight, even more preferably 40% to 50% by weight (based on the total weight of the polyolefin composition) of at least one high-density polyethylene having a melt flow rate MFR5 (190 °C, 5 kg, measured according to ISO 1133) of at least 0.8 g / 10 min;

[0053] In one embodiment, the weight-average molecular weight Mw (determined by GPC) of at least one high-density polyethylene is from about 110,000 g / mol to about 280,000 g / mol. In another embodiment, the weight-average molecular weight Mw (determined by GPC) of at least one high-density polyethylene is greater than about 110,000 g / mol to less than about 260,000 g / mol. In a further embodiment, the weight-average molecular weight Mw (determined by GPC) of at least one high-density polyethylene is from about 125,000 g / mol to about 240,000 g / mol, or from about 135,000 g / mol to 220,000 g / mol.

[0054] In one embodiment, the density (according to ISO 1183-1) of at least one high-density polyethylene is at least 900 kg / m 3 , preferably at least 950 kg / m 3 , particularly in the range of 930 kg / m 3 to 970 kg / m 3 , preferably 940 kg / m 3 to 960 kg / m 3 , more preferably 950 kg / m 3 to 960 kg / m 3 range.

[0055] In another embodiment, the melt flow rate MFR5 (5 kg, 190 °C, measured according to ISO 1133) of at least one high-density polyethylene is at least 0.9 g / 10 min, preferably at least 1 g / 10 min, particularly in the range of 0.8 g / 10 min to 2.0 g / 10 min, preferably 0.85 g / 10 min to 1.5 g / 10 min, more preferably 0.9 g / 10 min to 1.2 g / 10 min.

[0056] In another embodiment, the melt flow rate MFR2 (2.16 kg, 190 °C, measured according to ISO 1133) of at least one high-density polyethylene is at least 0.1 g / 10 min, preferably at least 0.15 g / 10 min, more preferably at least 0.2 g / 10 min, particularly in the range of 0.1 g / 10 min to 0.8 g / 10 min, preferably 0.15 g / 10 min to 0.5 g / 10 min, more preferably 0.2 g / 10 min to 0.3 g / 10 min.

[0057] In yet another embodiment, the B10 ESCR of at least one high density polyethylene is above 800 hours (measured at 50 °C in 10% Igepal under condition B according to ASTM D1693), preferably above 1000 hours, more preferably above 1500 hours, even more preferably above 2000 hours, particularly in the range of 600 hours to 10,000 hours, preferably 800 hours to 8000 hours, more preferably 1000 hours to 5000 hours.

[0058] In yet another embodiment, the impact strength (ISO179-1, Charpy 1eA +23 °C) of at least one high density polyethylene is at least 30 kJ / m 2 , preferably at least 35 kJ / m 2 , more preferably at least 40 kJ / m 2 , still more preferably at least 45 kJ / m 2 , particularly in the range of 30 kJ / m 2 to 50 kJ / m 2 , more particularly in the range of 33 kJ / m 2 to 48 kJ / m 2 , even more particularly in the range of 35 kJ / m 2 to 47 kJ / m 2 .

[0059] In one embodiment, bimodal polyethylene is used as at least one virgin high density polyethylene in the polyolefin composition of the present invention. The properties and characteristics of the virgin bimodal polyethylene that can be used in the polyolefin composition of the present invention are described below.

[0060] As used herein, the term "bimodal" means that the polymer is composed of two polyethylene fractions that are produced under different polymerization conditions, resulting in different (weight average) molecular weights and molecular weight distributions of the fractions. The form of the molecular weight distribution curve of the multimodal polymer, i.e., the graphical appearance of the polymer weight fraction as a function of its molecular weight, will show two or more maxima, or will generally be significantly broader compared to the curve of a single fraction.

[0061] The bimodal polyethylene comprises polyethylene homopolymers and polyethylene copolymers.

[0062] The term "ethylene homopolymer" means a polymer formed essentially only of ethylene monomer units (i.e., 99.9 wt% or more ethylene). It will be understood that trace amounts of other monomers may be present since industrial ethylene contains trace amounts of other monomers.

[0063] The term "ethylene copolymer" means that the copolymer contains both ethylene and at least one α-olefin comonomer. The comonomer is one or more suitable α-olefins, such as but not limited to 1-butene, 1-hexene, 1-octene, etc., where 1-butene is preferred.

[0064] Bimodal polyethylene (BPE-1):

[0065] At least one bimodal polyethylene (BPE-1) contains a polyethylene homopolymer and a polyethylene copolymer. The copolymer is based on ethylene and 1-butene as comonomers. Preferably, based on the total weight of the polymer, the content of 1-butene in the polymer (determined by NMR) is in the range of 0.1 wt% to 2 wt%, preferably 0.2 wt% to 1.2 wt%, and more preferably 0.3 wt% to 1 wt%, for example, 0.5 wt%.

[0066] Its melt flow rate MFR5 (190 °C, 5 kg, measured according to ISO 1133) is in the range of 1.0 g / 10 min to 1.5 g / 10 min, preferably 1.1 g / 10 min to 1.3 g / 10 min, more preferably 1.1 g / 10 min to 1.2 g / 10 min.

[0067] The melt flow rate MFR2 (190 °C, 2.16 kg, measured according to ISO 1133) is in the range of 0.15 g / 10 min to 0.5 g / 10 min, preferably 0.2 g / 10 min to 0.4 g / 10 min, more preferably 0.25 g / 10 min to 0.3 g / 10 min.

[0068] Its B10 ESCR is above 800 hours (measured according to ASTM D1693 at 50 °C in 10% Igepal under Condition B according to ASTM D1693), preferably above 1000 hours, more preferably above 1500 hours, even more preferably above 2000 hours, particularly in the range of 800 hours to 10,000 hours, preferably 1000 hours to 8000 hours, more preferably 1500 hours to 5000 hours.

[0069] The density is about 940 kg / m 3 to 970 kg / m 3 , preferably 950 kg / m 3 to 960 kg / m 3 .

[0070] Its impact strength (ISO179-1, Charpy 1eA +23 °C) is at least 30 kJ / m 2 , preferably at least 35 kJ / m 2 , particularly in the range of 30 kJ / m 2 to 40 kJ / m2 within the range of, more particularly between 33 kJ / m 2 and 37 kJ / m 2 and, for example, is 35 kJ / m 2 .

[0071] It has a Young's modulus of from 900 MPa to 1000 MPa, preferably from 950 MPa to 980 MPa, more preferably from 970 MPa to 980 MPa; a yield strength of from 20 MPa to 30 MPa, preferably from 23 MPa to 26 MPa; and a fracture strain of from 25% to 50%, preferably from 30% to 40%.

[0072] Bimodal polyethylene (BPE-2):

[0073] At least one bimodal polyethylene (BPE-2) comprises a polyethylene homopolymer and a polyethylene copolymer. The copolymer is based on ethylene and 1-butene as comonomers. Preferably, based on the total weight of the polymer, the content of 1-butene in the polymer (determined by NMR) is in the range of from 0.1% by weight to 2% by weight, preferably from 0.2% by weight to 1.2% by weight, and more preferably from 0.3% by weight to 1% by weight, for example 0.5% by weight.

[0074] Its melt flow rate MFR5 (190 °C, 5 kg, measured according to ISO 1133) is in the range of from 0.5 g / 10 min to 1.5 g / 10 min, preferably from 0.7 g / 10 min to 1.2 g / 10 min, more preferably from 0.8 g / 10 min to 1.0 g / 10 min, for example 0.9 g / 10 min.

[0075] The melt flow rate MFR2 (190 °C, 2.16 kg, measured according to ISO 1133) is in the range of from 0.1 g / 10 min to 0.5 g / 10 min, preferably from 0.15 g / 10 min to 0.4 g / 10 min, more preferably from 0.2 g / 10 min to 0.3 g / 10 min.

[0076] Its B10 ESCR is above 600 hours (measured according to ASTM D1693 at 50 °C in 10% Igepal under condition B according to ASTM D1693), preferably above 1000 hours, more preferably above 1500 hours, even more preferably above 2000 hours, particularly in the range of from 600 hours to 8,000 hours, preferably from 1000 hours to 6000 hours, more preferably from 1500 hours to 5000 hours.

[0077] The density is about 940 kg / m 3 to 970 kg / m 3 and preferably 950 kg / m 3From 0 to 960 kg / m 3 。

[0078] Its impact strength (ISO 179-1, Charpy 1eA + 23 °C) is at least 35 kJ / m 2 , preferably at least 40 kJ / m 2 , particularly in the range of 35 kJ / m 2 to 55 kJ / m 2 , more particularly in the range of 40 kJ / m 2 to 50 kJ / m 2 , for example 46 kJ / m 2 。

[0079] It has a Young's modulus of 900 MPa to 1200 MPa, preferably 950 MPa to 1100 MPa, more preferably 1000 MPa to 1050 MPa; a yield strength of 25 MPa to 35 MPa, preferably 28 MPa to 30 MPa; and a fracture strain of 20% to 40%, preferably 22% to 25%.

[0080] Blend of recycled materials

[0081] The polyolefin composition of the present invention may comprise 35% to 80% by weight, preferably 40% to 70% by weight, more preferably 45% to 65% by weight, even more preferably 50% to 60% by weight, for example 55% by weight (based on the total weight of the polyolefin composition) of a polyethylene-rich blend of recycled plastic materials comprising polyethylene and polypropylene, said polyethylene-rich blend of recycled plastic materials being recovered from waste plastic materials derived from post-consumer waste and / or post-industrial waste, and having a melt flow rate MFR5 (190 °C, 5 kg, measured according to ISO 1133) of at least 0.8 g / 10 min.

[0082] The blend is obtained from a recycled waste stream. The blend can be recycled post-consumer waste or post-industrial waste, for example from the automotive industry, or alternatively, a combination of both. Particularly preferably, the blend consists of recycled post-consumer waste and / or post-industrial waste.

[0083] Preferably, the polyethylene-rich recycled material is obtained from recycled waste by plastic recycling methods known in the art. Such recycled materials are commercially available from, for example, Corepla (Italian Consortium for the collection, recovery, recycling of packaging plastic wastes), Resource Plastics Corp. (Brampton, Ontario), Kruschitz GmbH, Plastics and Recycling (Austria), Vogt Plastik GmbH (Germany), Mtm Plastics GmbH (Germany), etc. Non-exhaustive examples of polyethylene-rich recycled materials include: PURPOLEN PE (Mtm Plastics GmbH), food-grade rHDPE (BIFFA PLC), and a range of polyethylene-rich materials such as HD-LM02041 from PLASgran Ltd. It is believed that the present invention can be applied to a wide range of recycled polyethylene-rich materials or materials or compositions having a high content of recycled polyethylene. The polyethylene-rich recycled material can be in the form of granules. It can be obtained from the household waste stream (i.e., it is a product of household recycling), such as the "yellow bag" recycling system operating in some parts of Germany.

[0084] In one embodiment, the polyethylene-rich blend of recycled plastic materials comprises:

[0085] - a C2 fraction in an amount, as measured by NMR of the d2-tetrachloroethylene soluble fraction, of more than 97.0 wt%, preferably more than 98.0 wt%, more preferably more than 99.0 wt%, particularly in the range of 97.0 wt% to 99.5 wt%, preferably in the range of 97.5 wt% to 99.0 wt%, and

[0086] - a continuous C3 fraction in an amount, as measured by NMR of the d2-tetrachloroethylene soluble fraction, of 3.0 wt% or less, preferably 2.5 wt% or less, more preferably 1.5 wt% or less, even more preferably 1.0 wt% or less, particularly in the range of 0 wt% (not measurable) to 3.0 wt%, preferably 0.1 wt% to 2.0 wt%, more preferably 0.1 wt% to 1.5 wt%, even more preferably 0.1 wt% to 1.0 wt%, and still more preferably 0.1 wt% to 0.5 wt%.

[0087] In another embodiment, the polyethylene-rich blend of recycled plastics has a C4 content of less than 1.0 wt%, preferably less than 0.8 wt%, more preferably less than 0.5 wt% (as measured by NMR of the d2-tetrachloroethylene soluble fraction), a C6 content of less than 1.0 wt%, preferably less than 0.8 wt%, more preferably less than 0.5 wt% (as measured by NMR of the d2-tetrachloroethylene soluble fraction), and an undetectable LDPE content (as measured by NMR of the d2-tetrachloroethylene soluble fraction).

[0088] The polyethylene fraction of the recycled material can include recycled high-density polyethylene (rHDPE), recycled medium-density polyethylene (rMDPE), recycled low-density polyethylene (rLDPE), recycled linear low-density polyethylene (rLLDPE), and mixtures thereof. In one embodiment, the recycled material is high-density PE with an average density greater than 0.940 g / cm 3 , preferably greater than 0.945 g / cm 3 , most preferably greater than 0.950 g / cm 3 .

[0089] In another embodiment, the polyethylene-rich blend of recycled plastic materials further comprises additional components selected from the group consisting of polystyrene, stabilizers, polyamides, talc, chalk, paper, wood, metals, limonene, fatty acids, and mixtures thereof.

[0090] Due to the recycling source, the blend can contain: up to 10%, preferably up to 3 wt%, of organic fillers, and / or inorganic fillers, and / or additives, relative to the weight of the blend.

[0091] As described above, based on the total weight of the blend (A), the recycled blend can contain one or more additional components selected from the following:

[0092] - up to 3.0 wt% of stabilizers, preferably up to 2.0 wt% of stabilizers,

[0093] - up to 4.0 wt% of polyamides, preferably up to 2.0 wt% of polyamides,

[0094] - up to 3.0 wt% of talc, preferably up to 1.0 wt% of talc,

[0095] - up to 3.0 wt% of chalk, preferably up to 1.0 wt% of chalk,

[0096] - up to 1.0 wt% of paper, preferably up to 0.5 wt% of paper,

[0097] - up to 1.0 wt% of wood, preferably up to 0.5 wt% of wood, and

[0098] - Metals up to 0.5% by weight, preferably up to 0.1% by weight of metals.

[0099] According to one embodiment, the impact strength (ISO 179-1, Charpy 1eA + 23 °C) of the polyethylene-rich blend of recycled plastic materials is at least 25 kJ / m 2 , more preferably at least 28 kJ / m 2 , particularly in the range of 25 kJ / m 2 to 40 kJ / m 2 , more particularly in the range of 25 kJ / m 2 to 35 kJ / m 2 , even more particularly in the range of 25 kJ / m 2 to 30 kJ / m 2 range.

[0100] According to another embodiment, the melt flow rate MFR5 (5 kg, 190 °C, measured according to ISO 1133) of the polyethylene-rich blend of recycled plastic materials is at least 0.8 g / 10 min, preferably at least 1 g / 10 min, particularly in the range of 0.8 g / 10 min to 2.0 g / 10 min, preferably 0.8 g / 10 min to 1.5 g / 10 min.

[0101] The melt flow rate MFR2 (2.16 kg, 190 °C, measured according to ISO 1133) of the polyethylene-rich blend of recycled plastic materials is at least 0.1 g / 10 min, preferably at least 0.15 g / 10 min, more preferably at least 0.2 g / 10 min, but always not more than 0.5 g / 10 min; particularly in the range of 0.1 g / 10 min to 0.5 g / 10 min, preferably 0.2 g / 10 min to 0.45 g / 10 min.

[0102] The polyethylene-rich blend of recycled plastics has a Young's modulus of 800 MPa to 1000 MPa, preferably 840 MPa to 900 MPa; a yield strength of 20 MPa to 30 MPa, preferably 24 MPa to 26 MPa; and a fracture strain of 30% to 140%, such as 35% or 134%.

[0103] In another embodiment, the density of the recycled blend is 920 kg / m 3 to 980 kg / m 3 , preferably 950 kg / m 3 to 960 kg / m 3 .

[0104] In the following, more specific embodiments of the polymer composition according to the present invention are described.

[0105] In a first embodiment, a polyolefin composition is provided, which comprises:

[0106] a) 40 wt% to 50 wt% (based on the total weight of the polyolefin composition) of at least one high-density polyethylene (BPE-1) comprising at least one polyethylene homopolymer and at least one polyethylene copolymer, said at least one high-density polyethylene (BPE-1) having a melt flow rate MFR5 (190 °C, 5 kg, measured according to ISO 1133) of at least 1.0 g / 10 min and a B10 ESCR (measured according to ASTM D1693 at 50 °C in 10% Igepal under condition B) of more than 800 hours;

[0107] b) 50 wt% to 60 wt% (based on the total weight of the polyolefin composition) of a polyethylene-rich blend of recycled plastic materials (blend A1), wherein:

[0108] - the amount of the C2 fraction, as measured by NMR of the d2-tetrachloroethylene soluble fraction, is more than 98.0 wt%, particularly in the range of 98.5 wt% to 99.5 wt%, and

[0109] - the amount of the continuous C3 fraction, as measured by NMR of the d2-tetrachloroethylene soluble fraction, is ≤ 1.5 wt%, particularly in the range of 0.1 wt% to 1.5 wt%;

[0110] c) Optionally, additional additives, wherein the sum of all components always adds up to 100 wt%.

[0111] wherein the impact strength (ISO179-1, Charpy 1eA +23 °C) of the polyolefin composition is at least 35 kJ / m 2 .

[0112] In a second embodiment, a polyolefin composition is provided, which comprises:

[0113] a) 40 wt% to 50 wt% (based on the total weight of the polyolefin composition) of at least one high-density polyethylene (BPE-2) comprising at least one polyethylene homopolymer and at least one polyethylene copolymer, said at least one high-density polyethylene (BPE-2) having a melt flow rate MFR5 (190 °C, 5 kg, measured according to ISO 1133) of at least 0.8 g / 10 min and a B10 ESCR (measured according to ASTM D1693 at 50 °C in 10% Igepal under condition B) of more than 600 hours;

[0114] b) 50 wt% to 60 wt% (based on the total weight of the polyolefin composition) of a polyethylene-rich blend of recycled plastic materials (blend A2), wherein:

[0115] - If the amount of the C2 fraction as measured by NMR of the d2-tetrachloroethylene soluble fraction is 98.5% by weight or more, particularly in the range of 90.0% to 99.9% by weight, and

[0116] - If the amount of the consecutive C3 fraction as measured by NMR of the d2-tetrachloroethylene soluble fraction is 1.0% by weight or less, particularly in the range of 0.1% to 0.5% by weight;

[0117] c) Optional additional additives, where the sum of all components always adds up to 100% by weight.

[0118] where the impact strength (ISO 179-1, Charpy 1eA + 23 °C) of the polyolefin composition is at least 30 kJ / m 2 .

[0119] Stabilizer

[0120] As described above, the polyolefin composition of the present invention comprises at least one stabilizer, particularly at least one antioxidant.

[0121] Examples of antioxidants commonly used in the art are sterically hindered phenols (e.g., CAS No. 6683-19-8, also sold as Irganox 1010 FF TM by BASF), phosphorus-based antioxidants (e.g., CAS No. 31570-04-4, also sold as Hostanox PAR 24 (FF) TM by Clariant or sold as Irgafos 168 (FF) TM by BASF), sulfur-based antioxidants (e.g., CAS No. 693-36-7, as Irganox PS-802 FL TM by BASF).

[0122] At least one stabilizer may be present in the polyolefin composition in an amount of 0.05% to 0.5% by weight, preferably 0.08% to 0.4% by weight, more preferably 0.10% to 0.3% by weight (based on the total weight of the polymer composition).

[0123] Additional additives

[0124] In another embodiment, the polyolefin composition may comprise additional additives. Examples of additives for the composition are pigments or dyes (e.g., carbon black), antacids and / or UV agents, antistatic agents, nucleating agents, and agents for utilization (e.g., processing aids). Preferred additives are carbon black, at least one antioxidant, and / or at least one UV stabilizer.

[0125] Typically, based on the weight of the total composition, the amount of these additives ranges from 0 wt% to 5.0 wt%, preferably from 0.01 wt% to 3.0 wt%, more preferably from 0.01 wt% to 2.0 wt%.

[0126] Antacids are also commonly known in the art. Examples are calcium stearate, sodium stearate, zinc stearate, magnesium and zinc oxides, synthetic hydrotalcite (e.g., SHT, CAS No. 11097-59-9), lactates and lactylates, and calcium stearate (CAS No. 1592-23-0) and zinc stearate (CAS No. 557-05-1).

[0127] Common anti-blocking agents are natural silica, such as diatomaceous earth (e.g., CAS No. 60676-86-0 (SuperfFloss TM ), CAS No. 60676-86-0 (SuperFloss E TM ), or CAS No. 60676-86-0 (Celite499 TM ), synthetic silica (e.g., CAS No. 7631-86-9, CAS No. 7631-86-9, CAS No. 7631-86-9, CAS No. 7631-86-9, CAS No. 7631-86-9, CAS No. 7631-86-9, CAS No. 112926-00-8, CAS No. 7631-86-9, or CAS No. 7631-86-9), silicates (e.g., aluminum silicate (kaolin) CAS No. 1318-74-7, sodium aluminum silicate CAS No. 1344-00-9, calcined kaolin CAS No. 92704-41-1, aluminum silicate CAS No. 1327-36-2, or calcium silicate CAS No. 1344-95-2), synthetic zeolites (e.g., calcium sodium aluminosilicate hydrate CAS No. 1344-01-0, CAS No. 1344-01-0, or calcium sodium aluminosilicate hydrate CAS No. 1344-01-0).

[0128] The anti-UV agent is, for example, bis-(2,2,6,6-tetramethyl-4-piperidyl)-sebacate (CAS No. 52829-07-9, Tinuvin 770); 2-hydroxy-4-n-octyloxy-benzophenone (CAS No. 1843-05-6, Chimassorb 81). Preferred UV stabilizers can be low molecular weight UV stabilizers and / or high molecular weight UV stabilizers, such as n-hexadecyl 3,5-di-tert-butyl-4-hydroxybenzoate, a mixture of 2,2,6,6-tetramethyl-4-piperidinol and esters of higher fatty acids (mainly stearic acid), and / or poly((6-morpholino-s-triazine-2,4-diyl)(1,2,2,6,6-pentamethyl-4-piperidyl)imino)hexamethylene(1,2,2,6,6-pentamethyl-4-piperidyl)imino)).

[0129] It is to be understood that the present invention also relates to a method for producing a polyolefin composition as defined herein. The method comprises the following steps:

[0130] - providing a mixture of:

[0131] a) at least one high density polyethylene having a melt flow rate MFR5 (190 °C, 5 kg, measured according to ISO 1133) of at least 0.8 g / 10 min, in an amount of 20 wt% to 65 wt% (based on the total weight of the polyolefin composition);

[0132] b) a polyethylene-rich blend of recycled plastic materials in an amount of 35 wt% to 80 wt% (based on the total weight of the polyolefin composition), the polyethylene-rich blend of recycled plastic materials being recovered from waste plastic materials derived from post-consumer waste and / or post-industrial waste, wherein:

[0133] - the amount of the C2 fraction, as measured by NMR of the d2-tetrachloroethylene soluble fraction, is above 96.5 wt%, particularly in the range of 96.5 wt% to 99.9 wt%, and

[0134] - the amount of the consecutive C3 fraction, as measured by NMR of the d2-tetrachloroethylene soluble fraction, is ≤ 3.5 wt%, particularly in the range of 0.1 wt% to 3.5 wt%;

[0135] c) optional additional additives, wherein the sum of all components always adds up to 100 wt%,

[0136] - melting the mixture in an extruder, and

[0137] - optionally pelletizing the obtained polyolefin composition.

[0138] For the purposes of the present invention, any suitable melting and mixing means known in the art can be used to perform the mixing and melting.

[0139] However, the melting and mixing steps are preferably carried out in a mixer and / or blender, high-shear mixer or low-shear mixer, high-speed blender or twin-screw extruder. Most preferably, the melting and mixing steps are carried out in a twin-screw extruder such as a co-rotating twin-screw extruder. Such twin-screw extruders are well known in the art, and the person skilled in the art will adjust the melting and mixing conditions (such as melting temperature, screw speed, etc.) according to the process equipment.

[0140] The polyolefin composition according to the present invention can be used in a wide range of applications, for example in the manufacture of containers and bottles.

[0141] The present invention will now be described in more detail with reference to the examples.

[0142] Experimental Section

[0143] The following examples are included to demonstrate certain aspects and embodiments of the present invention as set forth in the claims. However, those skilled in the art should understand that the following description is merely illustrative and should not be construed as a limitation of the present invention in any way.

[0144] Test Methods

[0145] Unless otherwise defined, the following definitions of terms and determination methods apply to the above general description of the present invention and the following examples.

[0146] Production of multipurpose specimens (MPS) and Type 1 Charpy specimens

[0147] All MPS and Charpy type 1 bar specimens were produced via injection molding on an Engel Victory 60 (Engel, Austria) under the conditions described in ISO 3167 (Plastics—Multipurpose test specimens), ISO 179-1 (Plastics—Determination of Charpy impact properties—Part 1: Non-instrumented impact test), and ISO 17855-2 (Plastics—Polyethylene (PE) moulding 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, the MPS were used for tensile testing, and the type 1 bar specimens were used for Charpy notched impact testing according to ISO 179-1 after notching (see more information about the testing later).

[0148] Melt flow rate (MFR)

[0149] MFR measurements were carried out on a Zwick / Roell Mflow melt flow indexer (ZwickRoell, Germany) at 190 °C with 5 kg according to ISO 1133-1 (Plastics—Determination of the melt mass-flow rate (MFR) and melt volume-flow rate (MVR) of thermoplastics—Part 1: Standard method). Cutting was performed every 3 mm piston movement. The time between cuts was measured, and each extrudate was weighed on an ABS220-4 electronic balance (Kern & Sohn, Germany). The MFR in g / 10 min for each cut was calculated by extrapolation to 10 minutes. For each material, one measurement was made. Within one measurement, 6 cuts were made and used to calculate the mean value and standard deviation.

[0150] Environmental stress crack resistance (ESCR)

[0151] Environmental stress cracking resistance was tested according to ASTM D 1693, Method B using 10% Igepal at 50 °C with the Bell test. Specimens for testing were prepared by compression molding according to ISO 17855-2. The thickness of the compression molded sheet was 1.84 mm to 1.97 mm.

[0152] Density

[0153] Density measurements were carried out using a Sartorius CPA225D laboratory balance (Sartorius, Germany) according to ISO 1183-1 (Plastics - Methods for determining the density of non-cellular plastics - Part 1: Immersion method, liquid pycnometer method and titration method). Samples were cut from the sprue-sided shoulders of a multi-purpose specimen (MPS). In the first step, the corresponding samples were dried and weighed to measure their mass (m S,A ) in air. In the second step, the samples were immersed in deionized water and placed under a buoyancy cage connected to the balance so that the buoyancy of the samples (m S.IL ) could be measured without the need for a sinker. A wire was used to release the air bubbles from the samples, and the temperature of the immersion liquid was recorded for calculating its density (ρ IL ). The variables A and B were corrected with the measuring instrument and the sample density was calculated according to the following formula:

[0154]

[0155] For each material, the average value and standard deviation were calculated using five samples cut from separate MPSs.

[0156] Tensile properties

[0157] The mechanical properties (Young's modulus, yield strength, and fracture strain) were examined at 23 °C using a universal testing machine Zwick AllroundLine Z020 (Zwick Roell, Germany) equipped with multiple extensometers. The test parameters and MPS were used according to ISO 527-1 (Plastics – Determination of tensile properties – Part 1: General principles) and ISO 527-2 (Part 2: Test conditions for moulding and extrusion plastics), with a traverse speed of 1 mm / min for Young's modulus determination up to a strain of 0.25%, and thereafter 50 mm / min up to fracture. The calculation of tensile modulus, yield stress, and fracture strain was completed according to ISO 527-1. Thus, the tensile modulus was calculated by regression as the slope of the stress / strain curve between 0.05% and 0.25%, the yield stress as the stress at the first occurrence of an increase in strain without an increase in stress, and the fracture strain as the strain at which the sample fractured. The strain was recorded up to yield using the multiple extensometers. Thereby, the nominal strain was calculated according to ISO 527-1 by means of the crosshead displacement via method B. This process was integrated into the test software TestXpert III (v1.61, Zwick Roell, Germany) used and automated. For each material, five MPS were tested for calculating the mean value and standard deviation.

[0158] Charpy notched impact strength

[0159] Impact tests were carried out on injection-molded type 1 bar specimens on a Zwick / Roell HIT25P pendulum impact testing machine (Zwick Roell, Germany) according to ISO 179-1 (Plastics – Determination of Charpy impact properties – Part 1: Non-instrumented impact test) (see above information). After pre-testing to determine the appropriate pendulum size (5 J or 2 J pendulum), in each case, the pendulum with the highest available energy that still met the requirements was selected to test the corresponding material. Notches were produced using a Leica RM2265 microtome (Leica, Germany) and measured with a Mitutoyo Absolute 547-313 digital thickness gauge with a wedge tip. The test conditions were 23 °C and specimens with edge notches had a notch radius of 0.25 mm (1 eA). For each material, ten specimens were tested to calculate the mean value and standard deviation.

[0160] Oxidation induction temperature

[0161] The oxidation induction temperature (dynamic OIT) was characterized using a DSC 4000 differential thermal analysis (DTA) instrument (PerkinElmer, USA) according to ISO 11357-6 (Plastics – Differential scanning calorimetry (DSC) – Part 6: Determination of oxidation induction time (isothermal OIT) and oxidation induction temperature (dynamic OIT)). Samples were cut from the shoulders of injection-molded MPS and encapsulated in perforated aluminum pans. The average sample weight was approximately 5 mg. A single heating step from 23 °C to 300 °C was carried out at a heating rate of 10 K / min, using synthetic air as the purge gas and at a flow rate of 20 ml / min. The intersection point of the slopes before and during oxidation gave the oxidation onset or oxidation induction temperature (in °C). For each material, five samples cut from separate MPS were used to calculate the mean value and standard deviation.

[0162] Gel permeation chromatography (GPC)

[0163] According to ISO 16014-1:2003, ISO 16014-2:2003, ISO 16014-4:2003 and ASTM D 6474-12, the number-average molecular weight (Mn), weight-average molecular weight (Mw), z-average molecular weight (Mz), molecular weight distribution (MWD) described by the polydispersity index PDI = Mw / Mn, and its breadth are determined by gel permeation chromatography (GPC) using the following equations:

[0164]

[0165] For a constant elution volume interval ΔV i , where A i and M i are the chromatographic peak slice area and the polyolefin molecular weight (MW) respectively, related to the elution volume V i , and N equals the number of data points obtained from the chromatogram between the integration limits.

[0166] A high-temperature GPC instrument equipped with an infrared (IR) detector (IR4 or IR5 from PolymerChar, Valencia, Spain), three Agilent-PLgel Olexis columns, and one Agilent-PLgel Olexis guard column is used. As the solvent and mobile phase, 1,2,4-trichlorobenzene (TCB) stabilized with 250 mg / L of 2,6-di-tert-butyl-4-methylphenol is used. The chromatographic system is run at 160 °C and a constant flow rate of 1 mL / min. 200 μL of the sample solution is injected for each analysis. Data acquisition is performed using Agilent Cirrus software version 3.3 or PolymerChar GPC-IR control software.

[0167] The column set is calibrated using 19 narrow MWD polystyrene (PS) standards in the range of 0.5 kg / mol to 11,500 kg / mol by universal calibration (according to ISO 16014-2:2003). The PS standards are dissolved at room temperature over several hours. The conversion from the peak molecular weight of polystyrene to the molecular weight of polyolefin is completed using the Mark Houwink equation and the following Mark Houwink constants:

[0168] K PS = 19 x 10 -3 mL / g, α PS = 0.655

[0169] K PE = 39 x 10 -3 mL / g, α PE = 0.725

[0170] K PP = 19 x 10 -3 mL / g, α PP = 0.725

[0171] A third-order polynomial fitting was used to fit the calibration data.

[0172] All samples were prepared in the concentration range of 0.5 mg / ml to 1 mg / ml and dissolved at 160 °C for 3 hours under continuous gentle shaking, for PE.

[0173] NMR measurement

[0174] NMR measurement of virgin polyethylene polymer

[0175] Quantitative nuclear magnetic resonance (NMR) spectroscopy was used to quantify the comonomer content of the native polymer.

[0176] Using for 1 H and 13 C were recorded in the molten state using a Bruker Avance III 500 NMR spectrometer operating at 500.13 MHz and 125.76 MHz respectively for quantitative 13 C{ 1 H} NMR spectra. Nitrogen was used for all pneumatic devices. 13The C-optimized 7 mm magic-angle spinning (MAS) probe was used to record all spectra at 150 °C. Approximately 200 mg of the material was loaded into a 7 mm outer diameter zirconia MAS rotor and spun at 4 kHz. This setting was chosen primarily for the high sensitivity required for rapid determination and accurate quantification (Klimke, K., Parkinson, M., Piel, C., Kaminsky, W., Spiess, H.W., Wilhelm, M., Macromol. Chem. Phys. 2006; 207: 382., Parkinson, M., Klimke, K., Spiess, H.W., Wilhelm, M., Macromol. Chem. Phys. 2007; 208: 2128., Castignolles, P., Graf, R., Parkinson, M., Wilhelm, M., Gaborieau, M., Polymer 50 (2009) 2373). Standard single-pulse excitation was employed, using transient NOE at a short recycle delay of 3 s (Pollard, M., Klimke, K., Graf, R., Spiess, H.W., Wilhelm, M., Sperber, O., Piel, C., Kaminsky, W., Macromolecules 2004; 37: 813., Klimke, K., Parkinson, M., Piel, C., Kaminsky, W., Spiess, H.W., Wilhelm, M., Macromol. Chem. Phys. 2006; 207: 382.) and the RS-HEPT decoupling scheme (Filip, X., Tripon, C., Filip, C., J. Mag. Resn. 2005, 176, 239, Griffin, J.M., Tripon, C., Samoson, A., Filip, C., and Brown, S.P., Mag. Res. in Chem. 2007 45, S1, S198). A total of 1024 (1k) transients were acquired for each spectrum.

[0177] Quantification was performed on the 13 C{ 1 H} NMR spectra using a custom automated spectral analysis program. All chemical shifts were internally referenced to the bulk methylene signal (δ+) at 30.00 ppm (J. Randall, Macromol. Sci., Rev. Macromol. Chem. Phys. 1989, C29, 201).

[0178] Characteristic signals corresponding to incorporated 1-butene were observed (J. Randall, Macromol. Sci., Rev. Macromol. Chem. Phys. 1989, C29, 201.), and all amounts were calculated relative to all other monomers present in the polymer, with a quantification limit of 0.2 mol% butene.

[0179] Characteristic signals resulting from the incorporation of isolated 1-butene (i.e., EEBEE comonomer sequences) were observed. Considering the number of reported sites for each comonomer, the integral of the signal at 39.8 ppm attributed to the *B2 site was used to quantify the incorporation of isolated 1-butene:

[0180] B = I ＊B2

[0181] When characteristic signals resulting from the incorporation of consecutive 1-butene (i.e., EBBE comonomer sequences) were observed, considering the number of reported sites for each comonomer, the integral of the signal at 39.3 ppm attributed to the ααB2B2 site was used to quantify such consecutive 1-butene incorporation:

[0182] BB = 2 * Iαα B2B2

[0183] When characteristic signals resulting from the incorporation of non-consecutive 1-butene (i.e., EBEBE comonomer sequences) were also observed, considering the number of reported sites for each comonomer, the integral of the signal at 24.7 ppm attributed to the ββB2B2 site was used to quantify such non-consecutive 1-butene incorporation:

[0184] BEB = 2 * Iββ B2B2

[0185] Since the *B2 site of isolated (EEBEE) 1-butene and the *βB2B2 site of non-consecutively incorporated (EBEBE) 1-butene overlap respectively, the total amount of isolated 1-butene incorporation was corrected based on the amount of non-consecutive 1-butene present:

[0186] B = I ＊B2 -2 * Iββ B2B2

[0187] In the case where no other signals indicating other comonomer sequences (i.e., butene chain initiation) were observed, the total 1-butene comonomer content was calculated based only on the amounts of isolated (EEBEE) 1-butene, consecutive (EBBE) 1-butene, and non-consecutive (EBEBE) 1-butene comonomer sequences:

[0188] B 总计 = B + BB + BEB

[0189] Characteristic signals generated by saturated end groups were observed. The content of such saturated end groups was quantified using the average of the integrals of the signals at 22.8 ppm and 32.2 ppm, which respectively belong to the 2s site and the 3s site:

[0190] S = (1 / 2) * (I 2S + I 3S )

[0191] The relative content of ethylene was quantified using the integral of the main methylene (δ+) signal at 30.00 ppm:

[0192] E = (1 / 2) * Iδ +

[0193] The total ethylene comonomer content was calculated based on the main methylene signal and taking into account other observed comonomer sequences or ethylene units present in the end groups:

[0194] E 总计 = E + (5 / 2) * B + (7 / 2) * BB + (9 / 2) * BEB + (3 / 2) * S

[0195] Then the total mole fraction of 1-butene in the polymer was calculated as:

[0196] fB = B 总计 / (E 总计 + B 总计 )

[0197] The total comonomer incorporation of 1-butene in mole percentage was calculated from the mole fraction in the usual way:

[0198] B[mol%] = 100 * fB

[0199] The total comonomer incorporation of 1-butene in weight percentage was calculated from the mole fraction in the standard way:

[0200] B[wt%] = 100 * (fB * 56.11) / ((fB * 56.11) + ((1 - fB) * 28.05))

[0201] NMR measurement of recycled materials

[0202] Quantification was performed on the C2-rich fraction, PP (continuous C3), LDPE, and polyethylene short branches in polyethylene-based recyclates.

[0203] Using a Bruker AVNEO 400 MHz NMR spectrometer operating at 400.15 MHz for 1 H and 13 100.62 MHz for 13 13C, quantitative1 {H}-NMR spectra. Nitrogen was used for all pneumatic devices 13 C-optimized 10 mm extended temperature probe was used to record all spectra at 125 °C. Approximately 200 mg of the material was dissolved in approximately 3 ml of 1,2-tetrachloroethane-d2 (TCE-d2) together with approximately 3 mg of BHT (2,6-di-tert-butyl-4-methylphenol CAS 128-37-0) and chromium(III) acetylacetonate (Cr(acac)3), resulting in a 60 mM solution of the relaxant in the solvent {singh09}. To ensure a homogeneous solution, after initial sample preparation in a heating block, the NMR tube was further heated in a rotary oven for at least 1 hour. After insertion into the magnet, the tube was rotated at 10 Hz. Standard single-pulse excitation without NOE was used, with an optimized tip angle, 1 s recycle delay, and a two-stage WALTZ16 decoupling scheme {zhou07, busico07}. Each spectrum was acquired with a total of 6144 (6k) transients.

[0204] A dedicated computer program was used to process, integrate, and determine the relevant quantitative characteristics from the integration of the quantitative 13 C{ 1 H}-NMR spectra. All chemical shifts were indirectly referenced to the center methylene of the ethylene block (EEE) at 30.00 ppm using the chemical shift of the solvent. Characteristic signals corresponding to polyethylene and polypropylene with different short-chain branches (B1, B2, B4, B5, B6plus) were observed {randall89, brandolini00}.

[0205] Characteristic signals corresponding to the presence of polyethylene were observed, including isolated B1 branches (starB1 33.3 ppm), isolated B2 branches (starB2 39.8 ppm), isolated B4 branches (twoB4 23.4 ppm), isolated B5 branches (threeB5 32.8 ppm), all branches longer than 4 carbons (starB4plus 38.3 ppm), and the third carbon from the end of the saturated aliphatic chain (3s 32.2 ppm). If one or the other structural element was not observable, it was excluded from the equation. The intensity (Iddg) of the combined ethylene backbone methylene carbons, including polyethylene backbone carbons (dd 30.0 ppm), γ-carbons (g 29.6 ppm), 4s and threeB4 carbons (to be compensated later), was between 30.9 ppm and 29.3 ppm, excluding Tββ from polypropylene. The amount of C2-related carbons was quantified using all the signals mentioned according to the following equation:

[0206] fC C2总计= (Iddg - ItwoB4) + (IstarB1 * 6) + (IstarB2 * 7) + (ItwoB4 * 9) + (IthreeB5 * 10) + ((IstarB4plus - ItwoB4 - IthreeB5) * 7) + (I3s * 3)

[0207] When characteristic signals corresponding to the presence of polypropylene (PP, continuous C3) are observed at 46.7 ppm, 29.0 ppm, and 22.0 ppm, the amount of PP-related carbon is quantified using the integral of Sαα at 46.6 ppm:

[0208] fC PP = Isαα * 3

[0209] The weight percentages of the C2 fraction and polypropylene can be quantified according to the following equations:

[0210] weight C2级分 = fC C2总计 * 100 / (fC C2总计 + fC PP )

[0211] weight PP = fC PP * 100 / (fC C2总计 + fC PP )

[0212] Characteristic signals corresponding to various short-chain branches are observed, and since the relevant branches will be α-olefins, their weight percentages are quantified by quantifying the weight fraction of each:

[0213] f weight C2 = fC C2总计 – ((IstarB1 * 3) – (IstarB2 * 4) – (ItwoB4 * 6) – (IthreeB5 * 7)

[0214] f weight C3 (isolated C3) = IstarB1 * 3

[0215] f weight C4 = IstarB2 * 4

[0216] f weight C6 = ItwoB4 * 6

[0217] f weight C7 = IthreeB5 * 7

[0218] f total 重量％ = f weight C2 + f weight C3 + f weight C4 + f weight C6 + f weight C7

[0219] weight C7 = f weight C7 * 100 / f total 重量％

[0220] Normalization of all weight fractions yields the amounts of the weight percentages of all relevant branched chains:

[0221] f total 重量％总计 = f weight C2 + f weight C3 + f weight C4 + f weight C6 + f weight C7 + fC PP Total weight C2 = f weight C2 * 100 / f total 重量％总计

[0222] Total weight C3 = f weight C3 * 100 / f total 重量％总计

[0223] Total weight C4 = f weight C4 * 100 / f total 重量％总计

[0224] Total weight C6 = f weight C6 * 100 / f total 重量％总计

[0225] Total weight C7 = f weight C7 * 100 / f total 重量％总计

[0226] It can be assumed that the B5 branched chains produced only by the polymerization of ethylene under high pressure are almost constant in LDPE to estimate the content of LDPE. We found that if quantified as C7, the average amount of B5 is 1.46 wt%. In the case of this assumption, the LDPE content within a certain range (about 15 wt% (= LOQ) to 90 wt%) can be estimated, which, in terms of LOQ, depends on the SNR ratio of the three B5 signals:

[0227] wt% LDPE (based on total PO) = Total weight C7 * 100 / 1.46

[0228] wt% LDPE (based on C2-rich fraction) = weight C7 * 100 / 1.46

[0229] Blends of different recycled materials were used. The blends are characterized by the following properties:

[0230] Blend A1

[0231] MFR5 0.8 g / 10 min to 0.83 g / 10 min, MFR2 0.25 g / 10 min to 0.28 g / 10 min, density 0.95 kg / m 3 ; Young's modulus 900 MPa, yield strength 25.6 MPa, elongation at break 35.4%; impact strength (notched Charpy test at 23 °C) 26 KJ / m 2 to 27 KJ / m 2 , Total C2: 98.7 wt%; continuous C3 content 0.9 wt%

[0232] Blend A2

[0233] MFR5 is 1.4 g / 10 min to 1.5 g / 10 min, MFR2 is 0.45 g / 10 min to 0.5 g / 10 min, density 0.968 kg / m 3 ; Young's modulus 840 MPa, yield strength 24.0 MPa, fracture strain 134.3%; impact strength (notched Charpy test at 23°C) 28 KJ / m 2 to 29 KJ / m 2 , C2 total: 99.0 wt%; continuous C3 content 0.3 wt%

[0234] Blend A3 : Comparative example

[0235] MFR5 is 1.2 g / 10 min to 1.3 g / 10 min, MFR2 is 0.4 g / 10 min to 0.43 g / 10 min, density 0.95 kg / m 3 ; PE enthalpy 177.66 J / g, PE Tm 131.91°C, Young's modulus 899 MPa, yield strength 24.7 MPa, fracture strain 49.2%; impact strength (notched Charpy test at 23°C) 23 KJ / m 2 to 24 KJ / m 2 , C2 total: 96.1 wt%; continuous C3 content 3.7 wt%

[0236] The virgin polymers used are bimodal polyethylene BPE-1 and bimodal polyethylene BPE-2. Both are described above.

[0237] In Table 1 below, several examples (Comparative - CE; Invention - IE) are summarized. The blends of virgin polymers and recycled materials are produced on a twin-screw extruder. Table 1 shows the properties of the polyolefin compositions according to the present invention, such as melt flow rate, modulus, and Charpy notched impact strength.

[0238] Table 1 relates to polyolefin compositions comprising the following:

[0239] - Comparative example (CE1): bimodal polyethylene BPE-1;

[0240] - Comparative example (CE2): bimodal polyethylene BPE-2;

[0241] - Comparative example (CE3): blend of bimodal polyethylene BPE-2 and 30 wt% recycled material (blend A3);

[0242] - Comparative example (CE4): blend of bimodal polyethylene BPE-2 and 30 wt% recycled material (blend A2);

[0243] - Comparative Example (CE5): Blend of bimodal polyethylene BPE-2 and 50 wt% recycled material (Blend A3);

[0244] - Comparative Example (CE6): Blend of bimodal polyethylene BPE-2 and 55 wt% recycled material (Blend A3);

[0245] - Invention Example (IE1): Blend of bimodal polyethylene BPE-1 and approximately 55 wt% recycled material (Blend A1);

[0246] - Invention Example (IE2): Blend of bimodal polyethylene BPE-2 and approximately 55 wt% recycled material (Blend A2);

[0247] - Comparative Example (CE7): Recycled material blend (Blend A3);

[0248] - Comparative Example (CE8): Recycled material blend (Blend A1);

[0249] - Comparative Example (CE9): Recycled material blend (Blend A2).

[0250] The following additives were used: Antioxidants: AO1 (Irganox 1010), AO2 (Irgafos 168).

[0251] As can be seen in Table 1, at higher PE recyclate loadings, the effect of high purity is more pronounced. In the case of 30% recyclate, the difference in the impact strength of the composites is not obvious. In contrast, in the case of >50% recyclate, the composites prepared with Blend A1 and Blend A2 (continuous C3 content < 1.0 wt%) showed significantly higher impact strength than the composites prepared with Blend A3 (continuous C3 content of 3.7 wt%), even though the difference in the impact strength of these recyclates is not obvious.

[0252]

[0253]

Claims

1. A polyolefin composition, comprising: a) 20% to 65% by weight (based on the total weight of the polyolefin composition) of at least one high-density polyethylene comprising at least one polyethylene homopolymer and at least one polyethylene copolymer, said at least one high-density polyethylene having a melt flow rate MFR5 (190 °C, 5 kg, measured according to ISO 1133) of at least 0.8 g / 10 min and a B10 ESCR (measured according to ASTM D1693) of more than 600 hours; b) 35% to 80% by weight (based on the total weight of the polyolefin composition) of a polyethylene-rich blend of recycled plastic materials, said polyethylene-rich blend of recycled plastic materials being recovered from waste plastic materials derived from post-consumer waste and / or post-industrial waste, wherein: - the amount of the C2 fraction measured by NMR of the d2-tetrachloroethylene soluble fraction is above 96.5% by weight, particularly in the range of 96.5% to 99.9% by weight, and - the amount of the continuous C3 fraction measured by NMR of the d2-tetrachloroethylene soluble fraction is ≤ 3.5% by weight, particularly in the range of 0.1% to 3.5% by weight; c) Optionally, additional additives, wherein the sum of all components always adds up to 100% by weight, wherein the polyolefin composition is characterized in that: The impact strength (ISO 179-1, Charpy 1eA + 23 °C) is at least 25 kJ / m 2 .

2. The polyolefin composition according to claim 1, characterized in that, the polyolefin composition comprises: a) 30% to 60% by weight, preferably 35% to 55% by weight, more preferably 40% to 50% by weight (based on the total weight of the polyolefin composition) of said at least one high-density polyethylene, said at least one high-density polyethylene having a melt flow rate MFR5 (190 °C, 5 kg, measured according to ISO 1133) of at least 0.8 g / 10 min and a B10 ESCR (measured according to ASTM D1693) of more than 600 hours; b) 40% to 70% by weight, preferably 45% to 65% by weight, more preferably 50% to 60% by weight (based on the total weight of the polyolefin composition) of said polyethylene-rich blend of recycled plastic materials, said polyethylene-rich blend of recycled plastic materials being recovered from waste plastic materials derived from post-consumer waste and / or post-industrial waste, and c) Optionally, additional additives, wherein the sum of all components always adds up to 100% by weight.

3. The polyolefin composition according to claim 1 or 2, characterized in that, The polyolefin composition comprises at least one stabilizer, particularly at least one antioxidant.

4. The polyolefin composition according to any one of the preceding claims, characterized in that, The melt flow rate MFR5 (5 kg, 190 °C, measured according to ISO 1133) is at least 0.8 g / 10 min, preferably at least 0.85 g / 10 min, more preferably at least 0.9 g / 10 min, particularly in the range of 0.8 g / 10 min to 2.0 g / 10 min, preferably 0.85 g / 10 min to 1.5 g / 10 min, more preferably 0.9 g / 10 min to 1.2 g / 10 min.

5. The polyolefin composition according to any one of the preceding claims, characterized in that, The melt flow rate MFR2 (2.16 kg, 190 °C, measured according to ISO 1133) is at least 0.1 g / 10 min, preferably at least 0.15 g / 10 min, more preferably at least 0.2 g / 10 min, particularly in the range of 0.1 g / 10 min to 0.8 g / 10 min, preferably 0.15 g / 10 min to 0.5 g / 10 min, more preferably 0.2 g / 10 min to 0.3 g / 10 min.

6. The polyolefin composition according to any one of the preceding claims, characterized in that, The impact strength (ISO 179-1, Charpy 1eA + 23 °C) is at least 30 kJ / m 2 , preferably at least 33 kJ / m 2 , more preferably at least 35 kJ / m 2 , even more preferably at least 38 kJ / m 2 , in particular in the range from 25 kJ / m 2 to 50 kJ / m 2 , more particularly in the range from 30 kJ / m 2 to 40 kJ / m 2 , even more particularly in the range from 33 kJ / m 2 to 39 kJ / m 2 .

7. The polyolefin composition according to any one of the preceding claims, characterized in that, The density of the at least one high-density polyethylene (according to ISO 1183-1) is at least 900 kg / m 3 , preferably at least 950 kg / m 3 , in particular between 930 kg / m 3 and 970 kg / m 3 , preferably 940 kg / m 3 to 960 kg / m 3 .

8. The polyolefin composition according to any one of the preceding claims, characterized in that, The melt flow rate MFR5 (5 kg, 190 °C, measured according to ISO 1133) of said at least one high-density polyethylene is at least 0.9 g / 10 min, preferably at least 1 g / 10 min, particularly in the range of 0.8 g / 10 min to 2.0 g / 10 min, preferably 0.85 g / 10 min to 1.5 g / 10 min, more preferably 0.9 g / 10 min to 1.2 g / 10 min.

9. The polyolefin composition according to any one of the preceding claims, characterized in that, The melt flow rate MFR2 (2.16 kg, 190 °C, measured according to ISO 1133) of said at least one high-density polyethylene is at least 0.1 g / 10 min, preferably at least 0.15 g / 10 min, more preferably at least 0.2 g / 10 min, particularly in the range of 0.1 g / 10 min to 0.8 g / 10 min, preferably 0.15 g / 10 min to 0.5 g / 10 min, more preferably 0.2 g / 10 min to 0.3 g / 10 min.

10. The polyolefin composition according to any one of the preceding claims, characterized in that, The B10 ESCR (measured according to ASTM D1693) of said at least one high-density polyethylene is above 800 h, preferably above 1000 h, more preferably above 1500 h, even more preferably above 2000 h, particularly in the range of 600 h to 10,000 h, preferably 800 h to 8000 h, more preferably 1000 h to 5000 h.

11. The polyolefin composition according to any one of the preceding claims, characterized in that, The impact strength (ISO 179-1, Charpy 1eA +23 °C) of said at least one high-density polyethylene is at least 30 kJ / m 2 , preferably at least 35 kJ / m 2 , more preferably at least 40 kJ / m 2 , still more preferably at least 45 kJ / m 2 , in particular in the range of 30 kJ / m 2 to 50 kJ / m 2 , more particularly in the range of 33 kJ / m 2 to 48 kJ / m 2 , even more particularly in the range of 35 kJ / m 2 to 47 kJ / m 2 .

12. The polyolefin composition according to any one of the preceding claims, characterized in that, The polyethylene-rich blend of the recycled plastic material has: - a C2 fraction in an amount, measured by NMR of the d2-tetrachloroethylene soluble fraction, of above 97.0 wt%, preferably above 98.0 wt%, more preferably above 99.0 wt%, particularly in the range of 97.0 wt% to 99.5 wt%, preferably in the range of 97.5 wt% to 99.0 wt%, and - a continuous C3 fraction in an amount, measured by NMR of the d2-tetrachloroethylene soluble fraction, of below 3.0 wt%, preferably below 2.5 wt%, more preferably below 1.5 wt%, even more preferably below 1.0 wt%, particularly in the range of 0 wt% (not determinable) to 3.0 wt%, preferably 0.1 wt% to 2.0 wt%, more preferably 0.1 wt% to 1.5 wt%, even more preferably 0.1 wt% to 1.0 wt%, still more preferably 0.1 wt% to 0.5 wt%.

13. The polyolefin composition according to any one of the preceding claims, characterized in that, The polyethylene-rich blend of the recycled plastics has a C4 content of less than 1.0 wt%, preferably less than 0.8 wt%, more preferably less than 0.5 wt% (measured by NMR of the d2-tetrachloroethylene soluble fraction), a C6 content of less than 1.0 wt%, preferably less than 0.8 wt%, more preferably less than 0.5 wt% (measured by NMR of the d2-tetrachloroethylene soluble fraction), and an undeterminable LDPE content (measured by NMR of the d2-tetrachloroethylene soluble fraction).

14. The polyolefin composition according to any one of the preceding claims, characterized in that, The impact strength (ISO 179-1, Charpy 1eA +23 °C) of the polyethylene-rich blend of the recycled plastic material is at least 25 kJ / m 2 , more preferably at least 28 kJ / m 2 , in particular between 25 kJ / m 2 and 40 kJ / m 2 , more particularly between 25 kJ / m 2 and 35 kJ / m 2 , even more particularly between 25 kJ / m 2 and 30 kJ / m 2 .

15. The polyolefin composition according to any one of the preceding claims, characterized in that, The melt flow rate MFR5 (5 kg, 190 °C, measured according to ISO 1133) of the polyethylene-rich blend of the recycled plastic material is at least 0.8 g / 10 min, preferably at least 1 g / 10 min, particularly in the range of 0.8 g / 10 min to 2.0 g / 10 min, preferably 0.8 g / 10 min to 1.5 g / 10 min.

16. The polyolefin composition according to any one of the preceding claims, characterized in that, The melt flow rate MFR2 (2.16 kg, 190 °C, measured according to ISO 1133) of the polyethylene-rich blend of the recycled plastic material is at least 0.1 g / 10 min, preferably at least 0.15 g / 10 min, more preferably at least 0.2 g / 10 min, but always not more than 0.5 g / 10 min; particularly in the range of 0.1 g / 10 min to 0.5 g / 10 min, preferably 0.2 g / 10 min to 0.45 g / 10 min.

17. Use of a polyolefin composition according to any of the preceding claims for products obtained by blow molding, particularly for containers and bottles for use in the household, cosmetics, chemical industry and food packaging.

18. A process for producing a polyolefin composition according to any of the preceding claims, wherein the process comprises the following steps: - providing a mixture of: a) 20 wt% to 65 wt% (based on the total weight of the polyolefin composition) of at least one high density polyethylene having a melt flow rate MFR5 (190 °C, 5 kg, measured according to ISO 1133) of at least 0.8 g / 10 min and a B10 ESCR of more than 600 h (measured according to ASTM D1693); b) 35 wt% to 80 wt% (based on the total weight of the polyolefin composition) of a polyethylene-rich blend of recycled plastic material recovered from waste plastic materials derived from post-consumer waste and / or post-industrial waste, wherein: - the amount of the C2 fraction measured by NMR of the d2-tetrachloroethylene soluble fraction is above 96.5 wt%, particularly in the range of 96.5 wt% to 99.9 wt%, and - the amount of the continuous C3 fraction measured by NMR of the d2-tetrachloroethylene soluble fraction ≤ 3.5 wt%, particularly in the range of 0.1 wt% to 3.5 wt%; c) optional further additives, where the sum of all components always adds up to 100 wt%, - melting the mixture in an extruder, and - Optionally, granulate the obtained polyolefin composition.

19. An article, in particular a container and a bottle, comprising a polyolefin composition according to any one of the preceding claims 1 to 12.

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