RU2858478C2 - Polyolefin composition containing polypropylene homopolymer, polypropylene block copolymer and recycled plastic material - Google Patents

Abstract

FIELD: polyolefin compositions.

SUBSTANCE: polyolefin composition for manufacturing articles from polyolefin material recovered from waste plastic material is proposed, containing, mas.%: 5-30 of a polypropylene homopolymer, 1-15 of a polypropylene block copolymer, 20-50 of a mixture of polypropylenes from mixed recycled material, 35-55 of glass fibre and optionally additional additives, wherein the sum of all ingredients always totals 100 mas.%; and an article containing the proposed polyolefin composition, wherein this article is an article from among structural articles, pumps, fans, household appliances, automotive parts, pipes and fittings.

EFFECT: development of a polyolefin composition containing a mixture of polyolefin material recovered from waste plastic material and virgin polymer, with an improved balance of stiffness and impact strength and high tensile strength.

14 cl, 1 tbl, 3 ex

Description

The invention relates to a polyolefin composition containing at least one polypropylene homopolymer, at least one polypropylene block copolymer and a recycled plastic material, as well as to an article containing such a polyolefin composition.

Description

Polyolefins, particularly polyethylene and polypropylene, are increasingly used in large quantities across a wide range of applications, including food and other packaging, fibers, automotive components, and a wide range of industrial products. Polyethylene-based materials pose a particular challenge, as they are widely used in packaging. Given the enormous amount of accumulated waste compared to the amount of waste returned for recycling, there is still significant potential for intelligent reuse of plastic waste streams and mechanical recycling of plastic waste.

Typically, recycled polypropylene volumes on the market are blends of both polypropylene (PP) and polyethylene (PE), which is especially relevant for post-consumer waste streams. Furthermore, commercial recyclates from post-consumer waste sources are typically subject to cross-contamination with non-polyolefin materials such as polyethylene terephthalate, polyamide, and polystyrene, or non-polymer substances such as wood, paper, glass, or aluminum. This cross-contamination severely limits the end-use areas of recycled streams, leaving no viable end-use areas. Polyolefin recyclates, especially from post-consumer waste streams, are blends of PE and PP. The higher the quality of the recyclate, the less available and the more expensive it is.

Consumers ordering recycled materials require the same stiffness and impact resistance ratio as virgin materials. This also applies to glass fiber-reinforced compounds for structural products. The quality issue of recycled materials compared to virgin materials can be addressed to some extent by reinforcing recycled materials, where particles of reinforcing material physically bind dissimilar regions (PP and PE).

Composites containing virgin polymers (i.e. polymers used for the first time) and recycled mixed plastics were studied.

Document WO 2014167493 A1 describes a method for producing a polyolefin blend comprising the step of (a) mixing together a base polymer blend MB and a polymer blend MPR, wherein said MPR blend is obtained by recycling post-consumer plastic materials.

Recycled mixed plastics reinforced with glass fibers (GF) were also emitted. For example, recycled PP or PP/PE blends were reinforced with GF or hybrid GF with other fillers.

Document EP 2845876 B1 describes a composition comprising two or more resins and glass fibre, comprising: a resin mixture comprising polyethylene (PE) waste and polypropylene (PP) waste; long glass fibre with a length of 10 mm or more; and a rubber-based resin, wherein the composition comprises, based on 100 parts by weight of the resin mixture, 3-30 parts by weight of long glass fibre, 10-50 parts by weight of rubber-based resin and 10-35 parts by weight of LDPE.

Document EP 3406662 A1 describes structurally reinforced plastic composite articles obtained using recycled waste glass fibers and recycled polymer compounds, as well as a method for producing the same. The reinforced composite article comprises: recycled glass fibers collected from waste streams and functioning as a filler, wherein the recycled glass fibers constitute 30-70% of the total weight of the reinforced composite article; a colorant in an amount of 1-2% of the total weight of the reinforced composite article; and a recycled resin collected from waste streams and substantially impregnating the recycled glass fibers with a black colorant and a chemical binder. The recycled resin comprises at least one resin from high-density polyethylene (HDPE), polypropylene (PP), or an engineering-grade resin.

Document WO 2018086959 A1 relates to a polyolefin composition containing a glass fiber filler, as well as to an article containing primary homopolymers and copolymers, 5-30% by weight of glass fiber filler and a compatibilizer.

Bajracharya et al. (“Experimental and theoretical studies on the properties of injection molded glass fiber reinforced mixed plastics composites.” Composites Part A: Applied Science and Manufacturing, 2016, 84: 393–405) and Bajracharya et al. (“Durability characteristics and property prediction of glass fiber reinforced mixed plastics composites.” Composites Part B: Engineering, 2017, 116: 16–29) described the use of PE/PP recyclate in flake form from Repeat Plastics (Replas) Pty (Australia), which is collected from post-consumer and post-industrial plastic waste. The recyclate has a tensile modulus of 906 MPa. They are reinforced with 10, 20, and 30% CF (4.0 mm length and 13.7 μm diameter). The maximum tensile modulus of 3068 MPa was achieved with 30% CF.

Thus, there are examples of reinforced recyclates with good tensile modulus and simultaneously good impact strength. However, it would be useful to develop polyolefin composites with properties similar to those of virgin polymers but also containing post-consumer recyclates (PCR) to achieve end solutions that are more cost-effective in terms of _CO2 emissions.

Thus, the aim of the present invention is to develop a polyolefin composition comprising a mixture of a polyolefin material recovered from waste plastic material and a virgin polymer, with an improved balance of stiffness and impact strength and high tensile strength.

This goal is achieved by developing a polyolefin composition containing:

a) 5-30% by weight (based on the total weight of the polyolefin composition) of at least one polypropylene homopolymer,

b) 1-15% by weight (based on the total weight of the polyolefin composition) of at least one polypropylene block copolymer,

c) 20-50% by weight (based on the total weight of the polyolefin composition) of a mixture of polypropylene mixed plastics from recycled material having

(i) a crystalline fraction (CF) content, determined according to CRYSTEX QC analysis, in the range from 85.0 to 95.0% by weight, and

(ii) a soluble fraction (SF) content, determined according to CRYSTEX QC analysis, in the range from 5.0 to 15.0% by weight, wherein

(iii) said crystalline fraction (CF) has a propylene content (C3(CF)) determined by FTIR spectroscopy calibrated by quantitative ¹³ C-NMR spectroscopy in the range from 93.0 to 99.0 wt.%, and wherein

(iv) said crystalline fraction (CF) has an ethylene content (C2(CF)), determined by FTIR spectroscopy calibrated by quantitative ^13C -NMR spectroscopy, in the range from 1.0 to 6.0 wt.%; and

(v) said soluble fraction (SF) has an intrinsic viscosity (IV(SF)) in the range from 1.0 to 2.0 dl/g, and

(vi) a mixture of polypropylene mixed plastics has a CIELAB color space (L*a*b*)

- L* from 30 to 97.0, in particular from 50 to 97.0;

- a* from -10.0 to 16.0, in particular from -8 to <10.0;

- b* from -5.0 to 25.0, in particular from -2 to 22.0;

d) 35-55% by weight (based on the total weight of the polyolefin composition) of glass fibers;

and optionally other additives, with the sum of all ingredients always amounting to 100% by weight, and the polyolefin composition having

- tensile modulus at 23°C of at least 7000 MPa (ISO 527-2),

- a tensile stress at yield at 23°C of at least 90 MPa (ISO 527-2), and

- impact strength (ISO179-1, Charpy 1eA +23°C) of at least 8.5 kJ/ ^m2 .

Accordingly, high-quality polypropylene recyclate is mixed with virgin polypropylene homopolymer, virgin polypropylene block copolymer and glass fiber to obtain a polyolefin composition with excellent mechanical properties, in particular, with excellent tensile strength and tensile stiffness, while maintaining the properties of the final composition, which are comparable to the properties of virgin polymers.

This recycled composite boasts a high tensile modulus combined with high tensile stress. The effectiveness of combining different types of polymers and glass fiber-reinforced recycled composites is difficult to predict. In particular, the tensile modulus and tensile stress are difficult to predict due to the interactions between the different components. Furthermore, polyolefin recycled composites are typically contaminated with polar polymers (e.g., PA, PET) or other non-PO polymers such as PS, or fillers, etc., making it difficult to predict the final mechanical properties.

The term "virgin" refers to newly produced materials and/or products prior to first use and not subjected to reprocessing. If the origin of a polymer is not explicitly stated, the polymer is considered "virgin."

For the purposes of the present description and the following claims, the term "recycled" is used to indicate that the material is derived from post-consumer waste and/or post-industrial waste. In this case, post-consumer waste refers to objects that have undergone at least the first cycle of use by a consumer (or life cycle), that is, have already served their primary purpose and passed through the hands of a consumer; post-industrial waste refers to manufacturing scrap that does not typically reach a consumer. According to the present invention, "recycled polymers" may also contain up to 17% by weight, preferably up to 3% by weight, more preferably up to 1% by weight, and even more preferably up to 0.1% by weight, based on the total weight of the recycled polymer, of other components originating from the first use. The type and amount of these components influence the physical properties of the recycled polymer. The physical properties given below relate to the main component of the recycled polymer.

Mixed plastics are defined as the presence of small amounts of compounds not typically found in virgin polypropylene blends, such as polystyrenes, polyamides, polyesters, wood, paper, limonene, aldehydes, ketones, fatty acids, metals, and/or long-term degradation products of stabilizers. Virgin polypropylene blends are defined as blends that originate directly during the manufacturing process, without intermediate use. By definition, "mixed plastics" can be equated to detectable amounts of polystyrene and/or polyamide-6 and/or limonene and/or fatty acids.

The total amount of all primary polypropylene homopolymers used in the polyolefin composition according to the invention is in the range of 5-30% by weight, preferably 8-25% by weight, more preferably 9-22% by weight (based on the total weight of the polyolefin composition).

The total amount of all primary polypropylene block copolymers used in the polyolefin composition according to the invention is in the range of 1-15% by weight, preferably 3-10% by weight, more preferably 4-8% by weight (based on the total weight of the polyolefin composition).

The amount of the polypropylene-mixed plastics mixture, which is preferably recovered from waste plastic materials obtained from post-consumer and/or post-industrial waste, used in this polyolefin composition, according to the invention, is in the range of 20-50% by weight, preferably 25-45% by weight, more preferably 30-42% by weight (based on the total weight of the polyolefin composition).

The amount of glass fiber used in the polyolefin composition according to the invention is in the range of 35-55% by weight, preferably 38-50% by weight, more preferably 38-45% by weight (based on the total weight of the polyolefin composition).

It should be understood that other additives may also be included in the polyolefin composition, and the sum of all ingredients always adds up to 100% by weight in each of the embodiments described herein.

According to an embodiment, the polyolefin composition comprises

a) 8-28% by weight, more preferably 9-22% by weight (based on the total weight of the polyolefin composition), of at least one polypropylene homopolymer,

b) 3-10% by weight, more preferably 4-8% by weight (based on the total weight of the polyolefin composition), of at least one polypropylene block copolymer,

c) 25-45% by weight, more preferably 30-42% by weight (based on the total weight of the polyolefin composition) of a mixture of polypropylenes and mixed plastics;

d) 38-50% by weight, preferably 38-45% by weight (based on the total weight of the polyolefin composition) of glass fibers;

and optionally other additives, with the sum of all ingredients ultimately adding up to 100% by weight.

In one embodiment, the polyolefin composition is also characterized by a melt flow rate MFR ₂ (ISO 1133, 2.16 kg, 230°C) of at least 3.0 g/10 min, preferably at least 3.5 g/10 min, more preferably at least 4.0 g/10 min, in particular in the range between 3.0 and 15 g/10 min, preferably in the range between 3.5 and 10 g/10 min, more preferably between 4.0 and 10 g/10 min.

In another embodiment, the polyolefin composition has a tensile modulus (ISO 527-2) of at least 8000 MPa, preferably at least 8500 MPa, more preferably at least 9000 MPa, such as in the range between 8000 and 15000 MPa, more particularly in the range between 8000 and 10000 MPa.

In a further embodiment, the polyolefin composition has a tensile stress at yield at 23°C (50 mm/min, ISO 527-2) of at least 95 MPa, preferably at least 100 MPa, more preferably at least 105 MPa, for example in the range between 90 and 200 MPa, more particularly in the range between 100 and 150 MPa.

In another embodiment, the polyolefin composition has a tensile strength at break at 23°C (50 mm/min, ISO 527-2) of at least 90 MPa, preferably at least 95 MPa, more preferably at least 100 MPa, even more preferably at least 105 MPa, for example in the range between 90 and 200 MPa, more particularly in the range between 100 and 150 MPa.

In yet another embodiment, the polyolefin composition has an impact strength (ISO179-1, Charpy 1eA +23°C) of at least 9.0 kJ/ ^m2 , preferably at least 9.5 kJ/ ^m2 , such as in the range between 9.0 and 15.0 kJ/ ^m2 , more particularly in the range between 9.5 and 13.0 kJ/ ^m2 , even more particularly in the range between 10 and 12.0 kJ/ ^m2 .

Polypropylene primary homopolymers

In an embodiment of this polyolefin composition, more than one primary polypropylene homopolymer can be used. However, it is preferable to use a single primary polypropylene homopolymer.

Thus, in an embodiment, the polyolefin composition may comprise

a1) at least one first polypropylene homopolymer;

a2) at least one second polypropylene homopolymer;

wherein at least one first polypropylene homopolymer and at least one second polypropylene homopolymer differ from each other in their melt flow rate MFR ₂ (230°C, 2.16 kg load, measured according to ISO 1133).

Thus, this polyolefin composition can contain two primary polypropylene homopolymers with different melt flow indices. This allows for easy adjustment of the melt flow index of the final polyolefin composition.

The polypropylene homopolymer used as the primary homopolymers in the polyolefin composition is selected from the group comprising

- a polypropylene homopolymer (PPG-1) having a melt flow rate MFR ₂ (230°C, 2.16 kg, measured according to ISO 1133) in the range of 5 to 15 g/10 min, preferably 5 to 10 g/10 min, more preferably 8 g/10 min; and/or

- a polypropylene homopolymer (PPG-2) having a melt flow rate MFR ₂ (230°C, 2.16 kg, measured according to ISO 1133) in the range of 10 to 30 g/10 min, preferably 15 to 25 g/10 min, more preferably 20 g/10 min.

The properties and characteristics of the various polypropylene homopolymers that can be used in this polyolefin composition are described below.

Polypropylene homopolymer (PPG-1)

At least one polyethylene homopolymer (PPG-1) has a melt flow rate MFR ₂ (230°C, 2.16 kg, measured according to ISO 1133) in the range of 5 to 15 g/10 min, preferably 5 to 10 g/10 min, more preferably 8 g/10 min; and a tensile modulus (ISO 178) higher than 800 MPa, preferably higher than 1000 MPa, more preferably higher than 1300 MPa

The polypropylene homopolymer (PPG-1) has a melting point of at least 150°C; preferably at least 158°C, preferably in the range from 158 to 167°C, for example 162°C. The polypropylene homopolymer (PPG-1) can have a flexural modulus, measured according to ISO 178, of at least 500 MPa, preferably at least 1000 MPa, preferably in the range from 1200 to 2000 MPa, for example 1400 MPa.

A preferred material for polypropylene homopolymer (PPG-1) is commercially available from Borealis AG (Austria) under the name HD601CF. Alternative suitable materials include highly crystalline polypropylene homopolymers, such as those described in WO 03/031174 A2.

Polypropylene homopolymer (PPG-2)

At least one polyethylene homopolymer (PPG-2) has a melt flow rate MFR ₂ (230°C, 2.16 kg, measured according to ISO 1133) in the range from 10 to 30 g/10 min, preferably from 15 to 25 g/10 min, preferably 20 g/10 min; and a tensile modulus (ISO 527-2) higher than 1800 MPa, preferably higher than 2000 MPa, most preferably 2200 MPa.

The polypropylene homopolymer (PPG-2) consists essentially of, i.e., more than 99.7% by weight, even more preferably at least 99.8% by weight, propylene units, based on the weight of the polypropylene homopolymer (PPG-2). In a preferred embodiment, only propylene units can be found in the polypropylene homopolymer (PPG-2).

It should be noted that the polypropylene homopolymer (PPG-2) is characterized by a low amount of cold xylene soluble fraction (XCS). The polypropylene homopolymer (PPG-2) can have a content of cold xylene soluble fraction (XCS) of no more than 4.0% by weight, preferably no more than 3.0% by weight, more preferably no more than 2.5% by weight, for example, in the range of 0.1 to 4.0% by weight, preferably in the range of 0.1 to 3.0% by weight, more preferably in the range of 0.1 to 2.5% by weight, based on the weight of the polypropylene homopolymer (PPG-2).

The polypropylene homopolymer (PPG-2) may have a heat distortion temperature (HDT), measured according to ISO 75-2, of at least 90°C, preferably at least 100°C, more preferably at least 115°C, for example in the range of 90 to 160°C, preferably in the range of 100 to 150°C, more preferably from 115 to 130°C.

The polypropylene homopolymer (PPG-2) may have a Charpy impact strength measured according to ISO 179-1eA at 23°C of at least 1.0 kJ/ ^m2 , preferably at least 2.0 kJ/ ^m2 , such as in the range of 1.0 to 10 kJ/ ^m2 , preferably in the range of 2.0 to 5.0 kJ/ ^m2 , such as 2.5 kJ/ ^m2 . The polypropylene homopolymer (PPG-2) may have a flexural modulus measured according to ISO 178 of at least 500 MPa, preferably at least 1500 MPa, such as in the range of 500 to 3500 MPa, preferably in the range of 1500 to 2500 MPa, such as 2000 MPa.

The polypropylene homopolymer (PPG-2) may contain a nucleating agent, which is preferably a polymeric nucleating agent, more preferably an alpha-nucleating agent, such as a polymeric alpha-nucleating agent. The alpha-nucleating agent content of the polypropylene homopolymer (PPG-2) is preferably up to 5.0% by weight. In a preferred embodiment, the polypropylene homopolymer (PPG-2) contains no more than 3000 ppm, more preferably from 1 to 2000 ppm, of the alpha-nucleating agent.

Polypropylene homopolymer (PPH-2) is known in the art and is commercially available from Borealis AG under the name HF955MO. PPH-2 is preferred.

Primary block copolymers of polypropylene

The properties and features of the primary polypropylene block copolymer that can be used in the present polyolefin composition are described below.

Polypropylene block copolymer (PBS-1)

In an embodiment, at least one polypropylene block copolymer (PBS-1) has a melt flow rate (230°C, 2.16 kg) of at least 0.10 g/10 min, preferably at least 0.20 g/10 min, such as in the range between 0.20 and 2.0 g/10 min, more particularly in the range between 0.20 and 1.5 g/10 min, such as 0.20-0.32 g/10 min.

The polypropylene block copolymer (PBS-1) may have a Charpy notched impact strength (NIS), measured according to ISO 179-1 eA at 23°C, of at least 40 kJ/ ^m2 , preferably at least 50 kJ/ ^m2 , for example in the range of 40 to 60 kJ/ ^m2 , preferably in the range of 45 to 55 kJ/ ^m2 , for example 50 kJ/ ^m2 . The polypropylene block copolymer (PBS-1) may have a tensile stress at yield, measured according to ISO 527-2, of at least 25 MPa, preferably at least 30 MPa, for example in the range of 25 to 45 MPa, preferably in the range of 30 to 35 MPa, for example 31 MPa. The density may be in the range of 800 to 1000 kg/ ^m3 , preferably in the range of 850 to 950 kg/ ^m3 , for example 900 kg/ ^m3 .

Polypropylene block copolymer (PBS-1) is known in the art and is, for example, commercially available from Borealis AG as BA212E.

A blend of polypropylene mixed plastics from recycled material

Mixed plastic polypropylene blend is derived from the recycled waste stream of post-consumer plastic waste.

Several possible feedstocks from municipal waste collection systems are commercially available and can be used to supply post-consumer plastic waste. Depending on consumer participation, the purity of this feedstock will vary, as typically indicated by the collection system. After step b), the intermediate product can also be tested for potentially very old ("ancient") clear/natural plastic items. Sorting is facilitated by color changes (e.g., pronounced yellowing) and/or visible scratches on predominantly clear/natural plastic items. This step eliminates so-called substances of very high concern. These substances, such as Pb, Hg, polybrominated diphenyl ethers, and the like, have long been banned, but are still present in the real world, as consumers typically accumulate plastic items, such as plastic toys, over many years and eventually discard them in waste collection systems. A follow-up analysis for these substances of very high concern can facilitate this additional screening step.

Odor monitoring and assessment are possible in several ways. A review of these is presented, for example, by Demets, Ruben, et al. in their publication "Development and application of an analytical method to quantify odor removal in plastic waste recycling processes," Resources, Conservation and Recycling 161 (2020):104907, which is incorporated herein by reference.

The polypropylene blend plastics mixture typically has a melt flow rate (ISO1133, 2.16 kg, 230°C) of 2.0 to 50 g/10 min. The melt flow rate can be influenced by separating post-consumer plastic waste streams, such as, but not limited to, those generated by extended producer responsibility schemes such as the German DSD, or by sorting municipal solid waste into a large number of pre-sorted fractions and recombining them in an appropriate manner. As an additional method for modifying the melt flow rate of the final polypropylene blend plastics mixture, peroxides can be added at the final granulation step. Typically, the MFR is in the range of 2.0 to 50 g/10 min, preferably 5.0 to 40 g/10 min, more preferably 10 to 30 g/10 min, and most preferably 15 to 25 g/10 min. This MFR range is particularly suitable for non-visbroken polypropylene blends of mixed plastics. Visbreaking can increase the MFR to 30 g/10 min or 40 g/10 min.

As a rule, the quality of processing can be assessed by the presence of one or more of the following substances:

a) polystyrene

b) polyamide-6

c) limonene, which is determined using solid-phase microextraction (HS-SPME-GC-MS)

d) fatty acids, which are determined using solid-phase microextraction (HS-SPME-GC-MS).

Presence refers to detection limits. The detection limit of limonene and fatty acids in solid-phase microextraction (HS-SPME-GC-MS) is less than 0.1 ppm, meaning traces of these substances allow for easy determination of processing quality.

The following quantities are preferred

a) polystyrene: from 0 to 2.0% by weight; more preferably from 0 to 0.5% by weight;

b) polyamide 6: from 0 to 1.5% by weight; more preferably from 0 to 0.5% by weight;

c) limonene determined using solid phase microextraction (HS-SPME-GC-MS): from 0.1 to 50 ppm;

d) fatty acids determined using solid phase microextraction (HS-SPME-GC-MS): from 0.1 to 200 ppm, more preferably 50 ppm.

It goes without saying that the amounts of a), b), c), and d) should be as low as possible. In a particularly preferred embodiment, the polypropylene blend does not contain polystyrene or polyamide, meaning that the content of both polymers is below the detection limit.

Various mixtures of polypropylene mixed plastics can be used.

Mixture of polypropylene mixed plastics (Mixture A1)

In one embodiment, the polypropylene blend of mixed plastics (Blend A1) has

(i) a crystalline fraction (CF) content, determined according to CRYSTEX QC analysis, in the range of 86.0 to 94.0 wt.%, more preferably 90.0 to 94.0 wt.%, and

(ii) a soluble fraction (SF) content, determined according to CRYSTEX QC analysis, in the range of from 6.0 to 14.0 wt.%, more preferably from 6.0 to 10.0 wt.%, wherein

(iii) said crystalline fraction (CF) has a propylene content (C3(CF)), determined by FTIR spectroscopy calibrated by quantitative ¹³ C-NMR spectroscopy, in the range from 93.0 to 99.0 wt.%, preferably from 95.0 to 98.0 wt.%; wherein

(iv) said crystalline fraction (CF) has an ethylene content (C2(CF)), determined by FTIR spectroscopy calibrated by quantitative ¹³ C-NMR spectroscopy, in the range of from 1 to 7% by weight, more preferably from 2.0 to 5.0% by weight, even more preferably from 2.5 to 3.5% by weight; and

(v) said soluble fraction (SF) has an intrinsic viscosity (IV(SF)) in the range from 1.2 to below 1.8 dl/g, preferably from 1.40 to 1.70 dl/g;

and

(vi) a mixture of polypropylene mixed plastics has a CIELAB color space (L*a*b*)

- L* from 40 to 85, preferably from 50 to 75;

- a* from -8.00 to 10, more preferably from -5.0 to 0.0;

- b* from 0.0 to below 10.0, more preferably from 0.0 to below 5.00.

The polypropylene blend of mixed plastics (Blend A1) preferably has a melt flow rate MFR ₂ (ISO 1133, 2.16 kg, 230°C) of at least 10.0 g/10 min, preferably at least 12.0 g/10 min, more preferably at least 14.0 g/10 min, for example in the range between 10.0 and 30.0 g/10 min, preferably between 12.0 and 25.0 g/10 min, more preferably between 14.0 and 20.0 g/10 min.

The content of the crystalline fraction (CF), determined according to the CRYSTEX QC analysis, in the mixture A1 is preferably in the range of 90.0 to 94.0% by weight, and the content of the soluble fraction (SF), determined according to the CRYSTEX QC analysis, is in the range of 6.0 to 10.0% by weight.

The polypropylene blend of mixed plastics (Blend A1) preferably has a soluble fraction (SF), obtained by CRYSTEX QC analysis, with an ethylene content (C2(SF)), determined by FTIR spectroscopy calibrated by quantitative ¹³ C-NMR spectroscopy, in the range of 20.0 to 30.0 wt.%, more preferably from 20.0 to 28.0 wt.%, even more preferably from 22.0 to 26.0 wt.% and most preferably from 23.0 to 25.0 wt.%.

The polypropylene blend of mixed plastics (Blend-A1) is preferably characterized by an odor (VDA270-B3) of 5.0 or lower, preferably 4.7 or lower, more preferably 4.0 or lower, such as 3.5.

In another aspect, the polypropylene blend of mixed plastics (Blend A1) has a large amplitude oscillatory shift - Non-linearity factor (LAOS-NLF) (190°C; 1000%) greater than 2.6, where

LAOS-NLF= ,

and

G ₁ ' is the first order Fourier coefficient;

G ₃ ' is the third order Fourier coefficient.

The polypropylene blend of mixed plastics (Blend-A1) has a tensile modulus of elasticity (ISO 527-2 at a crosshead speed of 1 mm/min; 23°C) using injection moulded test specimens as described in EN ISO 1873-2 (dog bone shape, 4 mm thick) of at least 1300 MPa, preferably at least 1330 MPa, for example 1440 MPa.

The polypropylene blend of mixed plastics (Blend A1) is found to have processability, as reflected by the shear thinning factor (STF), which is the ratio of eta 0.05 and eta 300, above 9.0, preferably above 10.0.

The Charpy notched impact strength (without tools, ISO 179-1 at +23°C) of the polypropylene blend plastics (Blend A1) is preferably higher than 4.5 kJ/ ^m2 , more preferably higher than 5.0 kJ/ ^m2 , most preferably higher than 5.4 kJ/ ^m2 , such as 6.9 kJ/ ^m2 .

The method for producing a mixture of polypropylene mixed plastics A1 includes the following stages:

a) obtaining a recirculation stream of mixed plastic precursor (A);

b) screening the recirculation stream of mixed plastic precursor (A) to create a recirculation stream of screened mixed plastic (B) containing only the largest size products in the range from 30 to 400 mm;

c) sorting the recirculation stream of screened mixed plastic (B) using one or more optical sorters, where the recirculation stream of screened mixed plastic (B) is sorted at least by colour and optionally also by type of polyolefin and/or shape of the article, as a result of which one or more recirculation streams of sorted polyolefins of a single colour (C) and a recirculation stream of sorted polyolefins of a mixed colour (CM) are obtained, where each of the one or more recirculation streams of sorted polyolefins of a single colour (C) and the recirculation stream of sorted polyolefins of a mixed colour (CM) are subjected separately to steps d) and further;

d) crushing the recycle stream of sorted polyolefins (C or CM) to obtain a recycle stream of flake polyolefin (D);

e) washing the recirculation stream of flake polyolefin (D) with a first aqueous washing solution (W1) without supplying thermal energy, thereby obtaining a first recirculation stream of suspended polyolefins (E);

f) removing at least a portion of the first aqueous wash solution (W1), preferably substantially all of the first aqueous wash solution (W1), from the first recycle stream of suspended polyolefins (E) to obtain a first recycle stream of washed polyolefins (F);

g) washing the first recirculation stream of washed polyolefins (F) with a second aqueous washing solution (W2) to thereby obtain a second recirculation stream of suspended polyolefins (G), wherein a sufficient amount of thermal energy is introduced into the second recirculation stream of suspended polyolefins (G) to obtain a temperature in the range of from 65 to 95°C during washing;

h) removing the second aqueous wash solution (W2) and any material not floating on the surface of the second aqueous wash solution from the second suspended polyolefin recycle stream (G) to obtain a second washed polyolefin recycle stream (H);

i) drying the second recycle stream of washed polyolefins (H) to obtain a recycle stream of dried polyolefins (I);

j) optionally separating the dried polyolefin recycle stream (I) into a light fraction and a heavy polyolefin recycle stream (J);

k) optionally further sorting the heavy fraction polyolefin recycle stream (J) or, if step j) is not present, the dried polyolefin recycle stream (I) using one or more optical sorters sorting into one or more target polyolefins by removing any flakes containing material other than the one or more target polyolefins, providing a purified polyolefin recycle stream (K);

l) optionally melt extruding, preferably pelletizing, a recycled stream of purified polyolefins (K), wherein additives (Ad) are preferably added in the molten state to obtain an extruded, preferably pelletized, product of recycled polyolefins (L); and

m) optionally aerating the recycled polyolefin product (L) or, if step l) is not present, the purified polyolefin recycle stream (K) to remove volatile organic compounds, thereby obtaining an aerated recycled polyolefin product (M), which is either an aerated extruded, preferably pelletized, recycled polyolefin product (M1) or an aerated recycled polyolefin flake (M2),

wherein the order of steps l) and m) can be mutually reversed such that the purified polyolefin recycle stream (K) is first aerated to form aerated recycled polyolefin flakes (M2), which are then extruded to obtain an extruded, preferably granulated, recycled polyolefin product (M3), which is the mixed colour polypropylene blend A1 described above.

Mixture of polypropylene mixed plastics (Mixture A2)

In another embodiment, the polypropylene blend of mixed plastics (Blend A2) has

(i) a crystalline fraction (CF) content, determined according to CRYSTEX QC analysis, in the range from 86.0 to 94.0 wt.%, preferably from 91.0 to 94.0 wt.%, and

(ii) a soluble fraction (SF) content, determined according to CRYSTEX QC analysis, in the range of from 6.0 to 14.0 wt.%, more preferably from 6.0 to 9.0 wt.%, wherein

(iii) said crystalline fraction (CF) has a propylene content (C3(CF)), determined by FTIR spectroscopy calibrated by quantitative ¹³ C-NMR spectroscopy, in the range from 95.0 to 99.0 wt.%, preferably from 96.0 to 98.0 wt.%, wherein

(iv) said crystalline fraction (CF) has an ethylene content (C2(CF)), determined by FTIR spectroscopy calibrated by quantitative ^13C -NMR spectroscopy, in the range of 1.0 to 5.0, preferably 2.0 to 4.0 wt.%, more preferably 2.5 to 3.5 wt.%; and

(v) said soluble fraction (SF) has an intrinsic viscosity (IV(SF)) in the range from 1.1 to below 1.5 dl/g, preferably from 1.25 to below 1.45 dl/g; wherein

(vi) a mixture of polypropylene mixed plastics has a CIELAB color space (L*a*b*)

- L* from 72.0 to 97.0, preferably from 80.0 to 97.0;

- a* from -5.0 to 0.0;

- b* from 0.0 to below 22.0.

The polypropylene blend of mixed plastics (Blend A2) preferably has a melt flow rate MFR ₂ (ISO 1133, 2.16 kg, 230°C) of at least 4.0 g/10 min, preferably at least 6.0 g/10 min, more preferably at least 7.0 g/10 min, for example in the range between 4.0 and 12.0 g/10 min, preferably between 6.0 and 10.0 g/10 min, more preferably between 7.0 and 9.0 g/10 min.

In one embodiment, the crystalline fraction (CF) content, determined according to the CRYSTEX QC analysis, in mixture A2 is preferably in the range of 91.0 to 94.0 wt.%, preferably 92 to 93 wt.%, and the soluble fraction (SF) content, determined according to the CRYSTEX QC analysis, is in the range of 6.0 to 9.0 wt.%, preferably 7.0 to 8.0 wt.%.

The polypropylene blend of mixed plastics (Blend A2) preferably has a soluble fraction (SF), obtained by CRYSTEX QC analysis, with an ethylene content (C2(SF)), determined by FTIR spectroscopy calibrated by quantitative ¹³ C-NMR spectroscopy, in the range of from 10.0 to 25.0 wt.%, more preferably from 12.0 to 25.0 wt.%, even more preferably from 12.0 to 20.0 wt.% and most preferably from 14.0 to 19.0 wt.%.

The polypropylene blend of mixed plastics (Blend-A2) preferably has an odor (VDA270-B3) of 4.0 or lower, preferably 3.0.

In another aspect, the polypropylene blend of mixed plastics has a large amplitude oscillatory shift - nonlinearity factor (LAOS -NLF) (190°C; 1000%) higher than 2.3, where

LAOS-NLF= ,

and

G ₁ ' is the first order Fourier coefficient,

G ₃ ' is the third order Fourier coefficient.

The polypropylene blend of mixed plastics has a tensile modulus of elasticity (ISO 527-2 at a crosshead speed of 1 mm/min; 23°C) using injection-molded test specimens described in EN ISO 1873-2 (dogbone shape, 4 mm thick) of at least 1200 MPa, preferably at least 1250 MPa. Typically, the tensile modulus of elasticity (ISO 527-2 at a crosshead speed of 1 mm/min; 23°C) of the second embodiment will not be higher than 1400 MPa.

The polypropylene blend of mixed plastics appears to have excellent processability as reflected by the shear thinning factor (STF), which is the ratio of eta 0.05 and eta 300, above 13.0, preferably above 14.0.

The Charpy notched impact strength (without tools, ISO 179-1 at +23°C) of the polypropylene blend plastics is preferably higher than 6.0 kJ/ ^m2 , more preferably higher than 8.0 kJ/ ^m2 , most preferably higher than 8.3 kJ/ ^m2 , such as 8.5 kJ/ ^m2 .

In a particularly preferred embodiment, the polypropylene blend of mixed plastics (Blend A2) has a Charpy notched impact strength (NIS) (1eA) (without tools, ISO 179-1 at +23°C) according to ISO 179-1 eA at +23°C on injection moulded test specimens of dimensions 80×10×4 mm prepared according to EN ISO 1873-2 of at least 8.0 kJ/m², preferably 8.3 kJ/m², wherein also said soluble fraction (SF), obtained by CRYSTEX QC analysis, has an ethylene content (C2(SF)), determined by FTIR spectroscopy calibrated by quantitative ¹³ C-NMR spectroscopy, in the range of from 12.0 to 20.0 wt.-%. and also preferably the polypropylene blend mixed plastics have a CIELAB color space (L*a*b)

- L* from 72.0 to 97.0, preferably from 80.0 to 97.0;

- a* from -5.0 to 0.0;

- b* from 0.0 to below 22.0

In this particular preferred embodiment, the crystalline fraction (CF) content, determined according to the CRYSTEX QC analysis, in mixture A2 is preferably in the range of 91.0 to 94.0 wt.%, and the soluble fraction (SF) content, determined according to the CRYSTEX QC analysis, is in the range of 6.0 to 9.0 wt.%.

The method for producing a mixture of A2 polypropylene mixed plastics includes the following stages:

a) recovery of post-consumer plastic waste;

b) sorting of goods made from polystyrene, polyamide, polyethylene, metals, paper and wood, resulting in post-consumer plastic material;

c) sorting of coloured goods to produce post-consumer plastic material comprising predominantly white bottles, predominantly white yogurt cups, predominantly white containers, predominantly clear panels, predominantly clear component parts, etc.;

d) crushing, washing with an aqueous solution containing various detergents and subsequent drying, wind sifting and testing of the selected post-consumer plastic material, predominantly white or colourless;

e) conducting additional sorting of pre-treated post-consumer plastic material to exclude non-polyolefin and painted parts;

f) extruding the material and obtaining a mixture of polypropylenes according to the present invention in the form of granules;

g) optionally aeration, which is preferably carried out at temperatures in the range of 100-130°C by heating the post-consumer plastic material to such temperature using an air flow having a temperature of at least 100°C.

Glass fibers

As mentioned above, the polyolefin composition according to the invention comprises glass fibers, in particular short glass fibers. The glass fibers used in the polyolefin composition according to the invention preferably have an average fiber length in the range of 2.0 to 10.0 mm, preferably from 2.0 to 8.0 mm, even more preferably from 2.0 to 6.0 mm, even more preferably in the range of 3.0 to 5.5 mm, even more preferably 3.5-5.0 mm.

It is also preferred that the short glass fibers used in the fiber-reinforced composite preferably have an average diameter of 5 to 20 μm, more preferably 8 to 18 μm, even more preferably 8 to 15 μm, even more preferably 10-15 μm, preferably 11-14 μm, preferably 12-14 μm, more preferably 12.3-13.7 μm, even more preferably 12.5-13.5 μm.

In one preferred embodiment, glass fibers having a fiber length of 3.0-5.0 mm (average 4.0 mm) and a fiber diameter of 12.3-13.7 μm (average 13 μm) are used. In another preferred embodiment, glass fibers having a fiber length of 3.5-5.5 mm (average 4.5 mm) and a fiber diameter of 12-14 μm (average 13 μm) are used.

Binding agent/dosing agent

In one embodiment, the polyolefin composition of the invention comprises at least one coupling agent. The at least one coupling agent is a functionalized polypropylene, such as a maleic anhydride (MAH)-functionalized polypropylene. The amount of coupling agent in the polyolefin composition may be 1-2 wt.%, such as 1 wt.% or 1.25 wt.%.

In one embodiment, the polyolefin composition may comprise at least one dosing agent for accepting fillers/pigments during extrusion. The at least one dosing agent may be a polypropylene homopolymer with a melt flow rate MFR ₂ between 1 and 5 g/10 min, preferably between 2 and 3 g/10 min, and a density between 800 and 100 kg/m ³ , preferably between 900 and 950 kg/m ³ . Such a polymer is commercially available from Borealis AG. The amount of dosing agent in the polyolefin composition may be 1-2 wt.%, such as 1.2-1.4 wt.%.

Supplements

In another embodiment, the polyolefin composition may contain additional additives. Examples of additives for use in the composition include pigments or dyes (e.g., carbon black), stabilizers (antioxidants), acid- and/or UV-protective agents, antistatic agents, nucleating agents, and recovery aids (such as processing aids). Preferred additives include carbon black, at least one antioxidant, and/or at least one UV stabilizer.

Typically, the amount of these additives is in the range of 0 to 5.0% by weight, preferably in the range of 0.01 to 3.0% by weight, more preferably from 0.01 to 2.0% by weight, based on the weight of the entire composition.

Examples of antioxidants that are commonly used in the art are sterically hindered phenols (such as CAS No. 6683-19-8, also sold as Irganox 1010 FF™ by BASF), phosphorus-based antioxidants (such as CAS No. 31570-04-4, also sold as Hostanox PAR 24 (FF)™ by Clariant, or Irgafos 168 (FF)™ by BASF), sulfur-based antioxidants (such as CAS No. 693-36-7, sold as Irganox PS-802 FL™ by BASF), nitrogen-based antioxidants (such as 4,4'-bis(1,1'-dimethyl-benzyl)diphenylamine), or mixtures of antioxidants. Preferred antioxidants may be tris(2,4-di-tert-butylphenyl)phosphite and/or octadecyl 3-(3',5'-di-tert-butyl-4-hydroxyphenyl)propionate.

Antacid agents are also well known in the art. Examples include calcium stearates, sodium stearates, zinc stearates, magnesium and zinc oxides, synthetic hydrotalcite (e.g., SHT, CAS No. 11097-59-9), lactates and lactylates, as well as calcium stearate (CAS No. 1592-23-0) and zinc stearate (CAS No. 557-05-1).

Common anti-caking agents are natural silicon dioxide such as diatomaceous earth (e.g., CAS No. 60676-86-0 (SuperfFloss™), CAS No. 60676-86-0 (SuperFloss E™), or CAS No. 60676-86-0 (Celite 499™)), synthetic silicon dioxide (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 (such as Aluminosilicate (Kaolin) CAS No. 1318-74-7, Sodium Aluminosilicate CAS No. 1344-00-9, Calcined Kaolin CAS No. 92704-41-1, Aluminosilicate CAS No. 1327-36-2 or Calcium Silicate CAS No. 1344-95-2), synthetic zeolites (such as Hydrated Sodium Calcium Aluminosilicate CAS No. 1344-01-0, or Sodium Calcium Aluminosilicate Hydrate CAS No. 1344-01-0).

UV protection agents include, for example, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate (CAS No. 52829-07-9, Tinuvin 770); 2-hydroxy-4-n-octoxybenzophenone (CAS No. 1843-05-6, Chimassorb 81). Preferred UV stabilizers may be low and/or high molecular weight UV stabilizers such as n-hexadecyl 3,5-di-tert-butyl 4-hydroxybenzoate, a mixture of esters of 2,2,6,6-tetramethyl-4-piperidinol and higher fatty acids (preferably stearic acid) and/or poly((6-morpholino-sym-triazine-2,4-diyl)-(1,2,2,6,6-pentamethyl-4-piperidyl)imino)hexamethylene(1,2,2,6,6-pentamethyl-4-piperidyl)imino)).

Alpha nucleating agents include sodium benzoate (CAS No. 532-32-1); 1,3:2,4-bis(3,4-dimethylbenzylidene)sorbitol (CAS 135861-56-2, Millad 3988).

Alpha nucleators may also be nucleators from the following:

(i) soluble nucleating agents such as sorbitol derivatives, for example di(alkylbenzylidene)sorbitols such as 1,3:2,4-dibenzylidenesorbitol, 1,3:2,4-di(4-methylbenzylidene)sorbitol, 1,3:2,4-di(4-ethylbenzylidene)sorbitol and 1,3:2,4-Bis(3,4-dimethylbenzylidene)sorbitol, as well as nonitol derivatives, for example 1,2,3-trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]nonitol, and benzene trisamides such as substituted 1,3,5-benzenetrisamides such as N,N',N"-tris-tert-butyl-1,3,5-benzenetricarboxamide, N,N’,N”-tris-cyclohexyl-1,3,5-benzene-tricarboxamide and N-[3,5-bis-(2,2-dimethylpropionylamino)phenyl]-2,2-dimethylpropionamide;

(ii) salts of monocarboxylic acids and polycarboxylic acids, such as sodium benzoate or aluminum tert-butyl benzoate;

(iii) salts of phosphoric acid diesters, such as sodium 2,2'-methylenebis(4,6,-di-tert-butylphenyl)phosphate or aluminum hydroxy-bis[2,2'-methylene-bis(4,6-di-tert-butylphenyl)phosphate] and aluminum hydroxy-bis(2,4,8,10-tetra-tert-butyl-6-hydroxy-12H-dibenzo(d,g)(1,3,2)dioxaphosphocin-6-oxidato)aluminum; and

(iv) inorganic nucleating agents such as talc.

Suitable antistatic agents are, for example, glycerol esters (CAS No. 97593-29-8), or ethoxylated amines (CAS No. 71786-60-2 or 61791-31-9), or ethoxylated amides (CAS No. 204-393-1).

Typically these additives are added in amounts of 100-2000 ppm for each individual polymer component.

More specific embodiments of the present composition are described below.

In a first embodiment, a polyolefin composition is provided that contains

a) 9-22% by weight (based on the total weight of the polyolefin composition) of at least one polypropylene homopolymer,

b) 4-6% by weight (based on the total weight of the polyolefin composition) of at least one polypropylene block copolymer,

c) 25-45% by weight (based on the total weight of the polyolefin composition) of a mixture of polypropylene mixed plastics (Mixture A1);

d) 38-42% by weight (based on the total weight of the polyolefin composition) of glass fibers;

and optionally other additives, with the sum of all ingredients ultimately adding up to 100% by weight.

Such a first polyolefin composition may have

- melt flow rate MFR ₂ (230°C, 2.16 kg, measured according to ISO 1133) in the range of 3.0-8.0 g/10 min; preferably in the range of 3.3 to 7.0 g/10 min, more preferably in the range of 3.5 to 6.0 g/10 min;

- a tensile modulus of elasticity (ISO 527-2) of at least 8500 MPa, preferably at least 9000 MPa,

- a tensile stress at yield at 23°C of at least 95 MPa, preferably at least 100 MPa,

- tensile stress at break at 23°C of at least 95 MPa, preferably at least 100 MPa,

- impact strength (ISO179-1, Charpy 1eA +23°C) of at least 9.0 kJ/ ^m2 , preferably at least 9.5 kJ/ ^m2 .

In a second embodiment, a polyolefin composition is provided that contains

a) 9-22% by weight (based on the total weight of the polyolefin composition) of at least one polypropylene homopolymer,

b) 4-6% by weight (based on the total weight of the polyolefin composition) of at least one polypropylene block copolymer,

c) 25-45% by weight (based on the total weight of the polyolefin composition) of a mixture of polypropylene mixed plastics (Mixture A2);

d) 38-42% by weight (based on the total weight of the polyolefin composition) of glass fibers;

and optionally other additives, with the sum of all ingredients ultimately adding up to 100% by weight.

Such a second polyolefin composition may have

- melt flow rate MFR ₂ (230°C, 2.16 kg, measured according to ISO 1133) in the range of 3.5 to 8.0 g/10 min; preferably in the range of 4.0 to 7.0 g/10 min, more preferably in the range of 4.3 to 6.0 g/10 min;

- a tensile modulus of elasticity (ISO 527-2) of at least 8500 MPa, preferably at least 8700 MPa,

- a tensile stress at yield at 23°C of at least 100 MPa, preferably at least 105 MPa,

- tensile stress at break at 23°C of at least 100 MPa, preferably at least 105 MPa,

- impact strength (ISO179-1, Charpy 1eA +23°C) of at least 10.0 kJ/ ^m2 , preferably at least 11 kJ/ ^m2 .

It should be noted that impact strength, yield stress, and tensile strength at break vary depending on the type of polypropylene blend (i.e., blend A1 or blend A2). For example, using a blend of polypropylene blends, as in blend A2, improves impact strength, yield stress, and tensile strength at break.

It should be noted that the present invention also relates to a method for producing polyolefin compositions as defined herein. The method comprises the steps of:

- obtaining a mixture of at least one polyethylene homopolymer; at least one polypropylene block copolymer, a mixture of polypropylenes, mixed plastics from recycled material, glass fibers, and at least one binding agent in the required quantities;

- melting the mixture in the extruder, and

- optional granulation of the obtained polyolefin composition.

For the purposes of the present invention, any suitable melting and mixing means known in the art may be used in performing the mixing and melting.

However, the melting and mixing step is preferably carried out in a mixer and/or blender, a high- or low-shear mixer, a high-speed blender, or a twin-screw extruder. Most preferably, the melting and mixing step is 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 one skilled in the art will be able to adapt the melting and mixing conditions (such as melting temperature, screw speed, etc.) to the processing equipment.

The polyolefin composition according to the invention can be used for a wide range of applications, such as for the manufacture of structural products, pumps, fans, household appliances, automotive parts, pipes and fittings, packaging, lids and closures.

Experimental part

The following examples are provided to demonstrate certain aspects and embodiments of the invention described in the claims. However, those skilled in the art should understand that the following description is illustrative only and should in no way be construed as limiting the invention.

Test methods

The following definitions of terms and methods of definition apply to the general description of the invention presented above, as well as to the examples given below, unless otherwise indicated.

a) CRYSTEX

Determination of crystalline and soluble fractions and their corresponding properties (IV and ethylene content)

The crystalline (CF) and soluble fractions (SF) of polypropylene (PP) composites, as well as the comonomer content and intrinsic viscosities of the corresponding fractions, were analyzed using a CRYSTEX instrument (Polymer Char, Valencia, Spain). Detailed information on the method and technique 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).

Crystalline and amorphous fractions are separated by temperature cycles of dissolution at 160°C, crystallization at 40°C, and redissolution in 1,2,4-trichlorobenzene at 160°C. Quantitative analysis of SF and CF and determination of ethylene ( _C2 ) content are performed using an integrated infrared detector (IR4), and a 2-capillary viscometer is used to determine the intrinsic viscosity (IV) in real time.

The IR4 detector is a multi-wavelength detector measuring IR absorption at two different bands ( _CH3 stretching (centered at approximately 2960 cm ^-1 ) and CH stretching (2700-3000 cm ^-1 )) which are used to determine the ethylene concentration and content in ethylene-propylene copolymers. The IR4 detector is calibrated using a set of 8 EP copolymers with known ethylene contents ranging from 2 to 69 wt% (determined by ^13C NMR), each having different concentrations ranging from 2 to 13 mg/mL. To determine both parameters simultaneously, the ethylene concentration and content, at the different polymer concentrations expected during Crystex analysis, the following calibration equations are used:

Conc. = a + b*Abs(CH) + c*(Abs(CH))² + d*Abs(CH ₃ ) + e*(Abs(CH ₃ )² + f*Abs(CH)*Abs(CH ₃ ) (Equation 1)

CH ₃ /1000C=a+b*Abs(CH) + c*Abs(CH ₃ ) + d*(Abs(CH ₃ )/Abs(CH)) + e*(Abs(CH ₃ )/Abs(CH))² (Equation 2)

The constants a through e for equation 1 and a through f for equation 2 are determined using ordinary least squares regression analysis.

The _CH3 /1000C ratio is converted to ethylene content in % by weight using the following relationship:

% wt. (ethylene in EP copolymers) = 100 - CH ₃ /1000TC * 0.3 (Equation 3)

The amounts of the soluble fraction (SF) and the crystalline fraction (CF) are correlated using the XS calibration relative to the amount of the "cold xylene soluble fraction" (XCS) and, respectively, the xylene insoluble fraction (XCI), which are determined by the standard gravimetric method in accordance with ISO 16152. The XS calibration is obtained by testing different EP copolymers with an XS fraction content in the range of 2-31% by weight. The resulting XS calibration is linear:

% wt. XS = 1.01 × % wt. SF (Equation 4)

The intrinsic viscosity (IV) of the base EP copolymer and its soluble and crystalline fractions is determined using an inline 2-capillary viscometer and is correlated with the corresponding IVs determined by the standard method in decalin according to ISO 1628-3. Calibration is obtained with different EP/PP copolymers with IVs of 2-4 dl/g. The resulting calibration curve is linear:

IV (dl/g)=a*Vsp/c (Equation 5)

Samples to be analyzed are weighed at concentrations ranging from 10 to 20 mg/ml. To eliminate potential gels and/or polymers that do not dissolve in TCB at 160°C, such as PET and PA, the weighed sample is packaged in a 0.077/D 0.05 mm stainless steel mesh.

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 is dissolved at 160°C until complete dissolution is achieved, typically within 60 minutes, with constant stirring at 400 rpm. To prevent sample degradation during dissolution, the polymer solution is placed under N ₂ .

A defined volume of sample solution is injected into a column filled with an inert support, where the sample crystallizes and the soluble fraction is separated from the crystalline one. This process is repeated twice. During the first injection, the entire sample is measured at high temperature, determining the IV [dL/g] and _C2 content (% by weight) in the polypropylene composition. During the second injection, the soluble fraction (at low temperature) and crystalline fraction (at high temperature) are measured using a crystallization cycle (% by weight SF, % by weight C2, IV).

b) Quantification of microstructure using NMR spectroscopy (calibration only)

Quantitative nuclear magnetic resonance (NMR) spectroscopy is used for calibration.

Quantitative ^13C { ^1H } NMR spectra were recorded in solution using a Bruker Avance Neo 400 NMR spectrometer operating at 400.15 and 100.62 MHz for ^1H and ^13C , respectively. All spectra were recorded using a 10 mm extended temperature probe head optimized for ^13C at 125°C with nitrogen gas applied to all pneumatic devices. About 200 mg of the material is dissolved in about 3 mL of 1,2-tetrachloroethane-d2 (TCE-d2) together with about 3 mg of BHT (2,6-di-tert-butyl-4-methylphenol, CAS No. 128-37-0) and chromium(III) acetylacetonate (Cr(acac) ₃ ) to make a 60 mM solution of the relaxing agent in solution as described in G. Singh, A. Kothari, V. Gupta, Polymer Testing 2009, 28(5), 475.

To obtain a homogeneous solution after the initial sample preparation in the heat block, the NMR vial is further heated in a rotary oven for at least 1 h. After insertion into the magnet, the vial is spun at 10 Hz. This setting is chosen primarily because of the high resolution and quantitative performance required for accurate ethylene determination. Standard single-pulse excitation without NOE is employed using an optimized tip angle, a 1 s recovery delay, and a WALTZ16 two-level decoupling network as described by 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. In total, 6144 (6 thousand) intermediate states are recorded for each spectrum.

Quantitative ¹³ C{ ¹ H} NMR spectra are processed, integrated, and the corresponding quantitative properties are determined using the integrals. All chemical shifts are indirectly assigned to the central methylene group of the ethylene block (CME) at 30.00 ppm using the solvent chemical shift. This approach allows for the use of comparable signals even in cases where this structural unit is missing.

The characteristic signals corresponding to the incorporation of ethylene are evaluated (as described in Cheng, H. N., Macromolecules 1984, 17, 1950), and the comonomer fraction is calculated as the fraction of ethylene in the polymer relative to the total monomer in the polymer:

fЭ=(Э/(П+Э).

The comonomer fraction was quantified using the method published by W.J. Wang, S. Zhu, Macromolecules 2000, 33 1157, by integrating multiple signals over the entire spectral region in the ¹³ C{ ¹ H} spectra. The integrated regions were slightly adjusted to improve applicability over the entire range of comonomer contents encountered.

The molar percentage of comonomer inclusion is calculated based on the molar fraction:

E [% mol.] = 100 * fE

The mass percentage of comonomer inclusion is calculated based on the molar fraction:

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

c) The tensile modulus and tensile stress at yield/break are measured according to ISO 527-2 (crosshead speed 1 mm/min; test speed 50 mm/min at 23°C) using injection moulded test specimens as described in EN ISO 1873-2 (dog bone shape, 4 mm thick). The measurements are carried out after conditioning the specimen for 96 hours.

d) Impact strength shall be determined as the Charpy notched impact strength (1eA) (without tools, ISO 179-1 at +23°C) according to ISO 179-1 eA at +23°C on injection moulded test specimens of dimensions 80 x 10 x 4 mm, obtained in accordance with EN ISO 1873-2.

e) Inorganic residues are determined by TGA according to DIN ISO 1172:1996 using a Perkin Elmer TGA 8000 apparatus. Approximately 10-20 mg of material is placed in a platinum pan. The temperature is equilibrated at 50°C for 10 minutes, then increased to 950°C under a nitrogen atmosphere at a heating rate of 20°C/min. The ash content is estimated as wt.% at 850°C.

f) MFR

Melt flow indices are measured under a 2.16 kg load (MFR ₂ ) at 230°C. Melt flow index is the amount of polymer in grams that an ISO 1133 testing device extrudes in 10 minutes at 230°C under a 2.16 kg load.

g) The amount of metals is determined by X-ray fluorescence (XRF).

h) Amount of paper, wood (for control purposes only)

Paper and wood can be identified by routine laboratory methods including comminution, flotation, microscopic analysis and thermogravimetric analysis (TGA).

i) Benzene content is determined by the HS GC-MS 80°C/2 h method, which is described as follows.

Static headspace analysis

The parameters of the applied method of static headspace gas chromatography-mass spectrometry (HS/GC/MS) are described below.

Weigh 4.000±0.100 g of sample into a 20 mL headspace (HS) vial and seal tightly with a PTFE lid.

The mass spectrometer operates in scanning mode, and a total ion chromatogram (TIC) is recorded for each analysis. Further details on the method parameters used and data evaluation are provided below:

- HS parameter (Agilent G1888 Headspace Sampler)

Vial equilibration time: 120 min

Oven temperature: 80°C

Circuit temperature: 205°C

Supply line temperature: 210°C

Low shaking

- GC Parameter (Agilent 7890A GC System)

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

Carrier gas: Helium 5.0

Flow rate: 2 ml/min

Flow division: 5:1

GC oven mode: 35°C for 0.1 min

10°C/min up to 250°C

250°C for 1 min

- MS parameter (Agilent 5975C inert XL MSD)

Data collection mode: Scan

Scanning parameters

Light weight: 20

High mass: 200

Threshold value: 10

- Software/Data Evaluation

Data processing: MSD ChemStation E.02.02.1431

Data collection: MassHunter GC/MS Acquisition B.07.05.2479

Analysis: AMDIS GC/MS Analysis Version 2.71

Mass Spectral Library: NIST Mass Spectral Library Version 2.0 g

- AMDIS deconvolution parameters

Minimum Match Rate: 80

Threshold: Low

Scan direction: high to low

Data file format: Agilent files

Device type: quadrupole

Component width: 20

Subtraction of adjacent peaks: two

Resolution: High

Sensitivity: Very high

Form Requirements: Average

Solvent tail formation: 44 m/z

Column carryover: 207 m/z

Min. model peaks: 2

Min. S/N: 10

Min. Some peaks: 0.5

Data evaluation

The TIC data are also deconvoluted using AMDIS software (see the parameters above) and compared to a custom target library based on the NIST mass spectral library. The custom target library includes the corresponding mass spectra of the selected compounds (e.g., benzene). Only when the identified peak shows a minimum match score of 80, and an experienced mass spectroscopy specialist confirms the match, is the compound considered "tentatively identified."

In this study, the term "below the limit of detection (<LOD)" refers to a condition in which either the coincidence ratio (AMDIS) is below 80 or the peak itself is not even detected. The results refer exclusively to the measured samples, measurement time, and parameters used.

j) Color CIELAB space (L*a*b*)

In the uniform color space CIE L*a*b*, measured according to the DIN EN ISO 11664-4 standard, the color coordinates are: L* is the lightness coordinate; a* is the coordinate of the red and green contents, where +a* indicates red and -a* indicates green; and b* is the coordinate of the yellow and blue contents, where +b* indicates yellow and -b* indicates blue. The coordinate axes L*, a*, and b* define the three-dimensional CIE color space. The standard colorimeter Konica/Minolta Colorimeter CM-3700A is used.

k) Smell VDA270-B3

The VDA 270 standard deals with the determination of odor characteristics of automotive trim materials. In this study, odor is determined in accordance with VDA 270 (2018), version B3. Each expert evaluates the odor of the respective sample according to the VDA 270 scale, lifting the lid of the can as little as possible. The hexameric scale consists of the following ratings: Class 1: not noticeable; Class 2: noticeable, but not bothersome; Class 3: distinctly noticeable, but not bothersome; Class 4: bothersome; Class 5: very bothersome; Class 6: unacceptable. The evaluators must remain calm during the evaluation and are prohibited from biasing each other by discussing individual results during the test. They are also not allowed to adjust their assessment after testing another sample. For statistical reasons (and in accordance with the VDA 270 standard), the evaluators are required to use all stages in their evaluation. Therefore, the odor rating is based on the average of all individual ratings and is rounded to whole numbers.

l) Determination of limonene

Quantitative determination of limonene can be achieved by solid-phase microextraction (HS-SPME-GC-MS) by adding standards.

Fifty mg of crushed samples are weighed into 20 mL headspace vials and, after the addition of limonene at various concentrations and a glass-lined magnetic stirrer, the vial is sealed with a silicone/PTFE-lined magnetic lid. Microcapillaries (10 pl) are used to add diluted limonene standards of known concentrations to the sample. Additions of 0, 2, 20, and 100 ng correspond to 0 mg/kg, 0.1 mg/kg, 1 mg/kg, and 5 mg/kg limonene. Additionally, standard additions of 6.6 mg/kg, 11 mg/kg, and 16.5 mg/kg limonene are used in combination with some of the samples tested in this application. Ion-93, obtained in SIM mode, is used for quantification. Volatile fraction enrichment is performed by headspace solid-phase microextraction using a 2-cm stable flexible fiber 50/30 pm DVB/Carboxen/PDMS at 60°C for 20 minutes. Desorption is performed directly into the heated injector of the GC-MS system at 270°C.

GC-MS parameters :

Column: 30 m HP 5 MS 0.25×0.25

Injector: Splitless with 0.75mm SPME insert, 270°C

Temperature conditions: -10°C (1 min)

Carrier gas: helium 5.0, linear velocity 31 cm/sec, constant flow

MS: single quadrupole, direct interface, interface temperature 280°C

Getting Data: SIM Scan Mode

Scanning parameter: 20-300 amu (atomic mass units)

SIM parameter: m/z 93, delay time 100 ms

m) Determination of fatty acid

Quantitative determination of fatty acid is carried out using solid-phase microextraction (HS-SPME-GC-MS) by adding standards.

Weigh 50 mg of the ground samples into 20 mL headspace vials and, after adding limonene at various concentrations and a glass-lined magnetic stirrer, close the vial with a silicone/PTFE-lined magnetic lid. Use microcapillaries (10 µL) to add a dilute mixture of free fatty acid standards (acetic acid, propionic acid, butyric acid, pentanoic acid, hexanoic acid, and octanoic acid) with known concentrations at three different levels to the sample. Additions of 0, 50, 100, and 500 ng correspond to 0 mg/kg, 1 mg/kg, 2 mg/kg, and 10 mg/kg of each individual acid. Ion-60, obtained in SIM mode, is used for quantification for all acids except propionic acid, where ion-74 is used.

GC-MS parameter :

Column: 20 m ZB Wax plus 0.25×0.25

Injector: 5:1 split with glass lined splitter insert, 250°C

Temperature conditions: 40°C (1 min) at 6°C/min up to 120°C, at 15°C/min up to 245°C (5 min)

Carrier: Helium 5.0, linear velocity 40 cm/sec, constant flow

MS: single quadrupole, direct interface, interface temperature 220°C

Getting Data: SIM Scan Mode

Scanning parameter: 46-250 amu, 6.6 scans/sec

SIM parameter: m/z 60, 74, scans/sec

n) The presence of polyamide-6 and polystyrene is determined by FTIR spectroscopy using the absorption band at 1601 cm ^-1 (PS) and 3300 cm ^-1 (PA6).

o) Determination of contamination on plates

Plates measuring 150 x 80 x 2 mm are produced using injection molding. A high-resolution image (photograph) is then captured on five plates (placed close together). The image is analyzed using software that automatically counts the number of visual defects (observable with the naked eye) due to contamination.

p) Dynamic shear measurements (Eta (2.7 kPa) and Eta (300 rad/sec))

Determination of polymer melt properties by dynamic shear measurements complies with ISO 6721-1 and 6721-10. Measurements are performed on an Anton Paar MCR501 variable-stress rotational viscometer equipped with a 25 mm parallel plate geometry. Measurements are performed on compression-molded plates under a nitrogen atmosphere and with the strain set to linear viscoelastic. Oscillatory shear tests are performed at 230°C, applying a frequency between 0.01 and 600 rad/sec and setting the gap to 1.3 mm.

In a dynamic shear experiment, the probe is subjected to uniform deformation under a sinusoidally varying shear strain or shear stress (controlled deformation and shear stress mode, respectively). In a controlled deformation experiment, the probe is subjected to sinusoidal deformation, which can be expressed using the equation:

(1).

If the applied strain is within the linear viscoelastic regime, the resulting sinusoidal stress response can be given by the equation:

(2),

Where

And represent the amplitudes of stress and strain, respectively;

means angular frequency;

means phase shift (loss angle between applied strain and stress response)

t stands for time.

The results of dynamic tests are typically expressed in terms of several different rheological functions, namely: the dynamic shear modulus, G’; the shear loss modulus, G”; the complex shear modulus, G*; the complex shear viscosity, ƞ*; the dynamic shear viscosity, ƞ’; the out-of-phase component of the complex shear viscosity, ƞ”; and the loss tangent, tan δ, which can be expressed as follows:

[Pa] (3)

[Pa] (4)

[Pa] (5)

[Pa⋅sec] (6)

[Pa⋅sec] (7)

[Pa⋅sec] (8).

ETA(x kPa) is determined using equation 9.

[Pa⋅sec] (9)

For example, ETA(2.7 kPa) is determined by the value of complex viscosity determined for a complex modulus of elasticity of 2.7 kPa.

Eta (x rad/sec) is determined using equation 10.

[Pa⋅sec] (10)

For example, ETA(300 rad/sec) is determined by the value of complex viscosity at a frequency sweep of 300 rad/sec.

q) The shear thinning factor (STF) is defined as

(11)

Values are determined using a single-point interpolation method defined by Rheoplus software. In situations where the specified G* value is not achieved experimentally, this value is determined by extrapolation using the same method as before. In both cases (interpolation or extrapolation), the Rheoplus software option “Interpolate y-values into x-values from parameter” and “logarithmic interpolation type” are used ([1] “Rheological characterization of polyethylene fractions” Heino, E.L., Lehtinen, A., Tanner J., Seppälä, J., Neste Oy, Porvoo, Finland, Theor. Appl. Rheol., Proc. Int. Congr. Rheol, 11th (1992), 1, 360–362; [2] “The influence of molecular structure on some rheological properties of polyethylene”, Heino, E.L., Borealis Polymers Oy, Porvoo, Finland, Annual Transactions of the Nordic Rheology Society, 1995.) [3] Definition of terms relating to the non-ultimate mechanical properties of polymers, Pure & Appl. Chem., Vol. 70, No. 3, pp. 701-754, 1998).

r) Large amplitude oscillatory shear (LAOS)

The study of nonlinear viscoelastic behavior under shear flow is performed using large-amplitude oscillatory shear. The method requires the application of a sinusoidal strain amplitude γ0, applied at a given angular frequency ω, for a given time t. Provided that the applied sinusoidal strain is sufficiently high, a nonlinear response is generated. The stress σ in this case is a function of the applied strain amplitude, time, and angular frequency. Under these conditions, the nonlinear stress response is still a periodic function; however, it can no longer be expressed using a single harmonic sine wave. The stress resulting from the nonlinear viscoelastic response [0-0] can be expressed using a Fourier series that includes contributions from higher harmonics:

(1)

Where

- σ - stress response

- t - time

- ω - frequency

- - deformation amplitude

- n is a harmonic number

- - Fourier coefficient of the n-th order for elasticity

- - Fourier coefficient of the n-th order for viscosity

The nonlinear viscoelastic response is analyzed using the large-amplitude oscillatory shear (LAOS) method. Time-domain measurements are performed on an Alpha Technologies RPA 2000 rheometer in combination with a standard biconical head. During measurements, the test chamber is sealed and a pressure of approximately 6 MPa is applied. The LAOS test is conducted at a temperature of 190°C, an angular frequency of 0.628 rad/sec, and a strain of 1000%. To achieve steady-state conditions, the nonlinear response is determined only after at least 20 measurement cycles. The large-amplitude oscillatory shear nonlinearity factor (LAOS-NLF) is determined by the formula:

(2),

Where

- first-order Fourier coefficient

- the third-order Fourier coefficient

(J. M. Dealy, K. F. Wissbrun, Melt Rheology and Its Role in Plastics Processing: Theory and Applications; edited by Van Nostrand Reinhold, New York (1990); S. Filipe, Non-Linear Rheology of Polymer Melts, AIP Conference Proceedings 1152, pp. 168-174 (2009); M. Wilhelm, Macromol. Mat. Eng. 287, 83-105 (2002) Reussner, Proceedings of Novel Non-Linear Rheological Parameters for Molecular Structural Characterization of Polyolefins, Novel Trends in Rheology IV, Zlin, Check Republik (2011); K. Klimke, S. Filipe, A. T. Tran, Non-linear rheological parameters for characterization of molecular structural properties in polyolefins, Proceedings of European Polymer Conference, Granada, Spain (2011)).

Table 1 summarizes the data for several examples (comparative - SP; declared - CP).

Various mixtures of recycled material are used. The mixtures are characterized by the following properties:

Mixture A1: C2(CF) content 2-3% by weight, C2(CS) content 24-25% by weight, C3(CF) content 95-96% by weight, MFR ₂ 14-17 g/10 min, tensile modulus 1300-1450 MPa, impact strength (Charpy test 23°C) 5-6 kJ/ ^m2

Mixture A2: C2(CF) content 2-3% by weight, C2(CS) content 17-18% by weight, C3(CF) content 97-98% by weight, MFR ₂ 7-8 g/10 min, tensile modulus 1250-1300 MPa, impact strength (Charpy test 23°C) 8-9 kJ/ ^m2

Mixtures A1 and A2 are prepared using the previously described method for obtaining mixed polypropylene plastics, which includes the stage of additional sorting of old (“ancient”) products, predominantly made of colorless/natural plastics, recognizable by a change in color (e.g., pronounced yellowing) and/or by pronounced scratches on products, predominantly made of colorless/natural plastics.

Comparative examples use other blends of recycled polypropylene composites. These additional blends have higher ethylene C2 content.

Mixture A3: total C2 content 9-10% by weight, C2(CF) content 8-12% by weight, C2(CS) content 29-34% by weight,

Blend A3 is a post-consumer polypropylene recyclate based on a material having a density (according to DIN EN ISO 1183) of 920 kg/ ^m3 ; melt flow rate (according to DIN EN ISO 1133, 230°C, 2.16 kg) of 14.1 g/10 min; moisture content (determined with an infrared moisture analyzer, 105°C) less than 0.1%; tensile modulus (according to DIN EN ISO 527, 1 mm/min) greater than 1100 MPa; yield strength (according to DIN EN ISO 527, 50 mm/min) greater than 25°MPa, and relative elongation (according to DIN EN ISO 527, 50 mm/min) greater than 180%.

Mixture A4: total content of C2 10-12% by weight, content of C2(CF) 7-10% by weight, content of C2(CS) 24-34% by weight.

Blend A4 is a post-consumer polypropylene recyclate based on a material having a density (according to DIN EN ISO 1183) of 916 kg/ ^m3 ; a melt flow rate (according to DIN EN ISO 1133, 230°C, 2.16 kg) of 36 g/10 min; a moisture content (determined with an infrared moisture analyzer, 105°C) less than 0.1%; a tensile modulus (according to DIN EN ISO 527, 1 mm/min) greater than 1100 MPa; a yield strength (according to DIN EN ISO 527, 50 mm/min) greater than 24 MPa; and an elongation (according to DIN EN ISO 527, 50 mm/min) greater than 18%.

Table 1 shows polyolefin compositions containing:

- Comparative example (CE1): one polyethylene homopolymer (PPG-2); a mixture of recycled material (Mixture A1) and 20% by weight of glass fiber;

- Comparative example (SP2): a mixture of recycled material (Mixture A1) and 30% by weight of glass fibre;

- Comparative example (SP3): one polyethylene homopolymer (PPG-1), a blend of recycled material (Blend A1) and 30% by weight glass fiber;

- Comparative example (SP4): one polyethylene homopolymer (PPG-2), one polypropylene block copolymer (PBS-1) and 40% by weight of glass fiber;

- Comparative example (SP5): a mixture of recycled material (Mixture A1) and 40% by weight glass fibre;

- Comparative example (SP6): one polyethylene homopolymer (PPG-2), one polypropylene block copolymer (PBS-1), a blend of recycled material (Blend A3) and 40% by weight glass fiber;

- Comparative example (SP7): one polyethylene homopolymer (PPG-2), one polypropylene block copolymer (PBS-1), a blend of recycled material (Blend A4) and 40% by weight glass fiber;

- Claimed example (CE1): one polyethylene homopolymer (PPG-2), one polypropylene block copolymer (PBS-1), a mixture of recycled material (Mixture A1) and 40% by weight of glass fiber;

- Claimed example (ZP2): one polyethylene homopolymer (PPG-2), one polypropylene block copolymer (PBS-1), a mixture of recycled material (Mixture A1) and 40% by weight of glass fiber;

- Claimed example (ZP3): one polyethylene homopolymer (PPG-2), one polypropylene block copolymer (PBS-1), a mixture of recycled material (Mixture A2) and 40% by weight of glass fiber.

Glass fiber can be purchased from one of the following suppliers: OC (Owens Corning), PPG/NEG, Johns Manville, 3B, Jushi, Taiwan Glass, Camelyaf, CPIC, Taishan. Glass fibers of grades 1.2 (average length 4 mm, average diameter 13 μm) and 4.1 (average length 4.5 mm, average diameter 13 μm) are used.

The following additives are used: Antioxidants - AO1 (Irganox 1010 (FF)), AO2 (Irganox B 225 (FF)), AO3 (Irganox PS-802 FL); black pigment (Plasblak PE6121, commercially available from Cabot); Dosing agent - HC001A-B1, PP homopolymer powder; Binding agent - AP 1.5, polypropylene, highly functionalized with maleic anhydride.

As can be seen in Table 1, the tensile strength values measured for ZP1, ZP2, and ZP3 are higher than those of SP1-SP3 and SP5-SP7. Furthermore, ZP1, ZP2, and ZP3 provide a tensile modulus of elasticity >8.8 GPa, which is significantly higher than that obtained in SP1-SP3. Furthermore, the Charpy impact strength is higher for ZP1-ZP3 compared to any of SP1-SP3 and SP6-SP7. Only SP4 (an example without any blend of recycled material) has better tensile modulus and tensile strength than any of ZP1-ZP3.

It should be noted that in ZP1-ZP3, when using a mixture of recycled raw materials with a lower C2 content than in the case of SP6 and SP7 with a higher C2 content, the polyolefin compositions have increased tensile strength and impact strength (according to Charpy).

Table 1

Components Unit SP1 SP2 SP3 SP4 SP5 SP6 SP7 ЗП1 ЗП2 ZP3 Fiberglass 1.2 % mass. 20 30 30 40 40 40 40 40 40 40 PPG-2 % mass. 45.3 47.2 9.8 9.8 21.6 9.8 9.8 PPG-1 33.4 PBS-1 % mass. 8 4 4 6 4 4 Supplements % mass. 3.7 3.7 3.7 4 4 4 4 4 4 4 Carbon black % mass. 0.8 0.8 0.8 0.8 0.8 0.8 0.8 Mixture A1 % mass. 66.3 32.9 55.2 27.6 41.4 Mixture A2 % mass. 31 41.4 Mixture A3 41.4 Mixture A4 41.4 Total 100 100 100 100 100 100 100 100 100 100 MFR 230°C/2.16 kg [g/10 min] 5.37 6.95 4.59 2.18 5.3 4.08 5.84 3.52 3.47 4.35 Tensile modulus at 23°C [MPa] 5090 6610 6794 10087 8887 8601 8952 9419 9122 8990 Tensile stress at yield point, 23°C [MPa] 73.17 80.9 87.75 131 97.17 92.36 95.39 106.78 101 109.3 Tensile strength at break at 50 mm/min, 23°C [MPa] 131.71 100.7 108.61 Flexural modulus 23°C [MPa] 9259 8354 8014 Flexural strength, 23°C [MPa] 179 137 145 Charpy 1eA +23°C [kJ/ ^m2 ] 7.71 8.74 8.4 12.87 9.61 8.07 8.43 9.65 9.86 11.46

Claims (53)

1. A polyolefin composition for the manufacture of articles from polyolefin material extracted from waste plastic material, containing a) 5-30 wt. %, based on the total weight of the polyolefin composition, of at least one polypropylene homopolymer, b) 1-15 wt. %, based on the total weight of the polyolefin composition, of at least one polypropylene block copolymer, c) 20-50 wt. %, based on the total weight of the polyolefin composition, of a mixture of polypropylenes of mixed plastics from recycled material, having (i) a crystalline fraction content CF, determined according to CRYSTEX QC analysis, in the range from 85.0 to 95.0 wt.%, and (ii) a soluble fraction content SF, determined according to CRYSTEX QC analysis, in the range from 5.0 to 15.0 wt.%, wherein (iii) said crystalline fraction CF has a propylene content C3(CF), determined by FTIR spectroscopy calibrated by quantitative ¹³ C-NMR spectroscopy, in the range from 93.0 to 99.0 wt. %, wherein (iv) said crystalline fraction CF has an ethylene content C2(CF), determined by FTIR spectroscopy calibrated by quantitative ¹³ C-NMR spectroscopy, in the range from 1.0 to 6.0 wt. %, and (v) said soluble fraction SF has an intrinsic viscosity IV(SF) in the range from 1.0 to 2.0 dl/g, and (vi) a mixture of polypropylene mixed plastics has a CIELAB color space (L*a*b*) - L* from 30 to 97.0, in particular from 50 to 97.0; - a* from -10.0 to 16.0, in particular from -8 to <10.0; - b* from -5.0 to 25.0, in particular from -2 to 22.0, d) 35-55 wt.%, based on the total weight of the polyolefin composition, glass fiber; and optionally additional additives, with the sum of all ingredients always adding up to 100% by weight. 2. A polyolefin composition according to claim 1, characterized in that it contains a) 8-28 wt.%, more preferably 9-22 wt.%, based on the total weight of the polyolefin composition, of at least one polypropylene homopolymer, b) 3-10 wt.%, more preferably 4-8 wt.%, based on the total weight of the polyolefin composition, of at least one polypropylene block copolymer, c) 25-45 wt.%, more preferably 30-42 wt.%, based on the total weight of the polyolefin composition, the mixture of polypropylenes of mixed plastics; d) 38-50 wt.%, preferably 38-45 wt.%, based on the total weight of the polyolefin composition, glass fiber; and optionally other additives, with the sum of all ingredients adding up to 100% by weight. 3. The polyolefin composition according to claim 1, characterized by a melt flow index MFR ₂ according to ISO 1133, 2.16 kg, 230 °C, of at least 3.0 g/10 min, preferably at least 3.5 g/10 min, more preferably at least 4.0 g/10 min, for example in the range between 3.0 and 15 g/10 min, preferably between 3.5 and 10 g/10 min, more preferably between 4.0 and 10 g/10 min. 4. The polyolefin composition according to claim 1, characterized by a tensile modulus according to ISO 527-2 of at least 7000 MPa, preferably at least 8000 MPa, more preferably at least 8500 MPa, even more preferably at least 9000 MPa, for example in the range between 8000 and 15000 MPa, more particularly in the range between 8000 and 10000 MPa. 5. The polyolefin composition according to claim 1, characterized by a tensile stress at yield, measured at 23°C, 50 mm/min, ISO 527-2, of at least 90 MPa, preferably at least 95 MPa, more preferably at least 100 MPa, even more preferably at least 105 MPa, for example in the range between 90 and 200 MPa, more particularly in the range between 100 and 150 MPa. 6. The polyolefin composition according to claim 1, characterized by a tensile stress at break, measured at 23°C, 50 mm/min, ISO 527-2, of at least 90 MPa, preferably at least 95 MPa, more preferably at least 100 MPa, even more preferably at least 105 MPa, for example in the range between 90 and 200 MPa, more particularly in the range between 100 and 150 MPa. 7. The polyolefin composition according to claim 1, characterized by an impact strength, measured according to ISO179-1, Charpy 1eA +23°C, of at least 8.5 kJ/ ^m2 , preferably at least 9.0 kJ/ ^m2 , more preferably at least 9.5 kJ/ ^m2 , for example in the range between 9.0 and 15.0 kJ/ ^m2 , more in particular in the range between 9.5 and 13.0 kJ/ ^m2 , even more in particular in the range between 10.0 and 12.0 kJ/ ^m2 . 8. The polyolefin composition according to claim 1, characterized in that at least one polypropylene homopolymer contains - a polypropylene homopolymer PPG-1 having a melt flow rate MFR ₂ , measured at 230°C, 2.16 kg, according to ISO 1133, in the range from 5 to 15 g/10 min, preferably from 5 to 10 g/10 min, more preferably 8 g/10 min; and/or - polypropylene homopolymer PPG-2, having a melt flow rate index MFR ₂ , measured at 230°C, 2.16 kg, according to the ISO 1133 standard, in the range from 10 to 30 g/10 min, preferably from 15 to 25 g/10 min, more preferably 20 g/10 min. 9. The polyolefin composition according to claim 1, characterized in that at least one polypropylene block copolymer has a melt flow index, measured at 230°C, 2.16 kg, of at least 0.2 g/10 min, preferably at least 0.3 g/10 min, for example in the range between 0.2 and 2.0 g/10 min, more particularly in the range between 0.2 and 1.5 g/10 min. 10. The polyolefin composition according to claim 1, characterized in that the mixture of polypropylene mixed plastics, designated as Mixture A1, has (i) a crystalline fraction CF content, determined according to CRYSTEX QC analysis, in the range from 86.0 to 94.0 wt.%, more preferably from 90.0 to 94.0 wt.%, and (ii) a soluble fraction content SF, determined according to CRYSTEX QC analysis, in the range from 6.0 to 14.0 wt.%, more preferably from 6.0 to 10.0 wt.%, wherein (iii) said crystalline fraction CF has a propylene content C3(CF), determined by FTIR spectroscopy calibrated by quantitative ¹³ C-NMR spectroscopy, in the range from 93.0 to 99.0 wt. %, preferably from 95.0 to 98.0 wt. %, and wherein (iv) said crystalline fraction CF has an ethylene content C2(CF), determined by FTIR spectroscopy calibrated by quantitative ^13C -NMR spectroscopy, in the range of from 1 to 7 wt.%, more preferably from 2.0 to 5.0 wt.%, even more preferably from 2.5 to 3.5 wt.%, and (v) said soluble fraction SF has an intrinsic viscosity IV(SF) in the range from 1.2 to below 1.8 dl/g, preferably from 1.40 to 1.70 dl/g, wherein (vi) a mixture of polypropylene mixed plastics has a CIELAB color space (L*a*b*) - L* from 40 to 85, preferably from 50 to 75; - a* from -8.00 to 10, more preferably -5.0 to 0.0; - b* from 0.0 to below 10.0, more preferably from 0.0 to below 5.00. 11. The polyolefin composition according to claim 1, characterized in that the mixture of polypropylene mixed plastics, designated as Mixture A2, has (i) a crystalline fraction CF content, determined according to CRYSTEX QC analysis, in the range from 86.0 to 94.0 wt.%, preferably from 91.0 to 94.0 wt.%, and (ii) a soluble fraction content SF, determined according to CRYSTEX QC analysis, in the range from 6.0 to 14.0 wt.%, more preferably from 6.0 to 9.0 wt.%, wherein (iii) said crystalline fraction CF has a propylene content C3(CF), determined by FTIR spectroscopy calibrated by quantitative ¹³ C-NMR spectroscopy, in the range from 95.0 to 99.0 wt. %, preferably from 96.0 to 98.0 wt. %, wherein (iv) said crystalline fraction CF has an ethylene content C2(CF), determined by FTIR spectroscopy calibrated by quantitative ¹³ C-NMR spectroscopy, in the range of 1.0 to 5.0 wt.%, preferably 2.0 to 4.0 wt.%, more preferably 2.5 to 3.5 wt.%, and (v) said soluble fraction SF has an intrinsic viscosity IV(SF) in the range from 1.1 to below 1.5 dl/g, preferably from 1.25 to below 1.45 dl/g, wherein (vi) a mixture of polypropylene mixed plastics has a CIELAB color space (L*a*b*) - L* from 72.0 to 97.0, preferably from 80.0 to 97.0; - a* from -5.0 to 0.0; - b* from 0.0 to below 22.0. 12. The polyolefin composition according to claim 1, characterized in that the glass fibers have a length of 2.0 to 10.0 mm, preferably in the range of 2.0 to 8.0 mm, even more preferably in the range of 2.0 to 6.0 mm, and a diameter of 5 to 20 μm, more preferably from 8 to 18 μm, even more preferably from 8 to 15 μm. 13. The polyolefin composition according to claim 1, characterized in that it additionally contains at least one binding agent, in particular polypropylene functionalized with maleic anhydride (MAN). 14. An article containing a polyolefin composition according to claim 1, wherein said article is one of the structural articles, pumps, fans, household appliances, automotive parts, pipes and fittings.