Polyolefin composition comprising heterophasic polypropylene polymers and recycled plastic materials for pipes
A polyolefin composition with heterophasic propylene copolymer and recycled polypropylene, stabilized by a metal deactivator, enhances thermal stability for pipe applications, overcoming the limitations of recycled plastics.
Patent Information
- Application Number
- PCT/EP2025/069695
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-07-11
- Filing Date
- 2025-07-10
- Publication Date
- 2026-01-15
AI Technical Summary
Recycled plastics, particularly polypropylene, are inferior in quality due to contamination and degradation, limiting their use in applications like pipes, and existing stabilizer systems are not effective for compositions containing recyclates.
A polyolefin composition comprising 40-90% heterophasic propylene copolymer, 10-60% recycled polypropylene blend, and a metal deactivator, which stabilizes the mixture to meet pipe performance standards by reducing the catalytic effect of metal ions.
The composition achieves excellent thermal oxidation stability, making it suitable for pipe applications while incorporating recycled materials, thus addressing the quality issues of recyclates.
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Abstract
Description
[0001] Polyolefin composition comprising heterophasic polypropylene polymers and recycled plastic materials for pipes
[0002] The invention relates to a polyolefin composition comprising at least one heterophasic polypropylene copolymer, and recycled plastic material, to an article, in particular a pipe, comprising the polyolefin composition and a process for preparing such polyolefin composition.
[0003] Description
[0004] Polyolefins, in particular polyethylene and polypropylene are increasingly consumed in large amounts in a wide range of applications, including packaging for food and other goods, fibres, automotive components, and a great variety of manufactured articles. Polyethylene based materials are a particular problem as these materials are extensively used in packaging. Taking into account the huge amount of waste collected compared to the amount of waste recycled back into the stream, there is still a great potential for intelligent reuse of plastic waste streams and for mechanical recycling of plastic wastes.
[0005] With their inherent versatility, plastics play crucial roles in a sustainable and resource-efficient economy. However, as more and more plastic has been created and used in a mode of linear economy, plastic waste is nowadays considered a serious social problem. For that, it is important to form a circular economy that brings plastic waste back to a second life, i.e., to recycle it. This not only avoids leaving plastic waste in the environment but also recovers its value.
[0006] The European Commission confirmed in 2017 that it would focus on plastics production and use. The EU goals are that 1 ) by 2025 at least 50% of all plastics packaging in the EU should be recycled and 2) by 2030 all plastic packaging placed in the EU market is reusable or easily recycled. This pushes the brand owners and plastic converters to pursue solutions with recyclates or virgin / recyclate blends. More recently, in 2021 , EU agreed tax on plastic packaging waste. The tax, introduced as of 1 January 2021 , is calculated on the weight of nonrecycled plastic packaging waste "with a call rate of €0.80 / kilogram with a mechanism to avoid excessively regressive impact on national contributions.”
[0007] It is therefore urgently needed to find ways of recycling plastic waste. However, recycled plastics are normally inferior to virgin plastics in their quality due to degradation, contamination and mixing of different plastics. Generally, recycled quantities of polypropylene on the market are mixtures of both polypropylene (PP) and polyethylene (PE), this is especially true for post-consumer waste streams. Moreover, commercial recyclates from post-consumer waste sources are conventionally crosscontaminated with nonpolyolefin materials such as polyethylene terephthalate, polyamide, polystyrene or nonpolymeric substances like wood, paper, glass or aluminum. These cross-contaminations drastically limit final applications of recycling streams such that no profitable final uses remain. The better the quality of the recyclate is, the less available it is and the more expensive it is.
[0008] The current standards for non-pressure polypropylene (PP) pipes are expected to be modified in 2024 to allow incorporation of post-consumer recyclate PP (PCR PP), and not only production scraps.
[0009] When recyclate PP is introduced to virgin polymer material, it brings along different kinds of contaminations which usually reduce the overall stability and deteriorate the pipe performance. In particular, metal ions such as Co, Fe, Cu, Mo, Ti, Zn, Pb, etc., are reported in the literature to deteriorate stability due to their catalytic effect on degradation. For example, copper and iron ions are known to catalyse the homolysis of hydroperoxides and increase the consumption of phenolic antioxidants through oxidation into dienoide compounds [Zweifel, H., Plastics additives handbook, 5th edition Hanser, Munich, 2001 ]. Catalyst residues from aluminium, titanium, chromium, and zirconium complexes deactivate phenolic antioxidants by complexation [Zweifel, H., Plastics additives handbook, 5th edition Hanser, Munich, 2001]. Furthermore, metal ions including iron, copper, chromium, titanium and zinc may also be introduced to the recycled plastics in the form of pigments [Gala, A.; Guerrero, M.; Serra, J. M., Characterization of post-consumer plastic film waste from mixed MSW in Spain: a key point for the successful implementation of sustainable plastic waste management strategies. Waste Management (Oxford, U. K.) 2020, 11 1 , 22-33].
[0010] Even in well-sorted and washed recyclates, a mixture of different catalyst residues is present due to the various proprietary systems used for the same type but different polymer grades. Hence, it is essential to find a suitable additive system for the selected compositions of recyclate PP / virgin PP to meet the requirements of pipe performance in the current industry standards (e.g., EN 1451 -1 , EN1852-1 ). It is known to add stabilization packages comprising phenolic and phosphorous-based antioxidants, calcium stearate, HALS and metal deactivator to polyolefin compositions. The presence of metal deactivator is found to greatly improve thermo-photo stability of such compositions.
[0011] For example, WO99 / 19397 A1 concerns a stabilized polyolefin composition containing metal deactivators in combination with a metal sulphide. Examples are based on polypropylene random copolymer. However, recyclates are not mentioned.
[0012] EP 0 565 868 A2 discloses a polyolefin composition having improved oxidative stability, the stabilized composition comprising an ethylene homopolymer or copolymer containing (a) a divalent metal-containing sterically hindered phenol compound and (b) a metal deactivator having one or more hindered phenol groups linked to a hydrazo or oxamido group. The stabilized polyolefin composition is useful in the insulation of wires and cables and are characterized by increased resistance to oxidation.
[0013] GB2252324 refers to a stabilizer system for polyolefins with NAUGARD XL-1 (CAS: 70331- 94-1) as a deactivator. It concerns a complex stabilizer composition which comprises (a) at least one sterically hindered phenol or amine antioxidant and (c) a metal deactivator, and at least one of (b) a neutraliser and (d) an antioxidant which is a phosphorus-containing compound or a thioether or sulphide.
[0014] Examples in the literature are primarily based on virgin polyethylene and not on virgin polypropylene and not on recyclates.
[0015] Thus, it was an object of the invention to provide a polyolefin composition wherein at least a part of virgin polyproyplene is replaced by polyolefin material recovered from waste plastic material.
[0016] It is in particular an object of the present invention to provide a composition, which is suitable for pipe applications complying with the standards of pipes, especially in terms of the thermal oxidation stability.
[0017] This object has been solved by providing a polyolefin composition comprising: a) in the range from 40 to 90 wt% (based on the overall weight of the polyolefin composition) of at least one heterophasic propylene copolymer (HECO,) having a total ethylene (C2) content as determined according to Crystex analysis as described in the method section from 0.5 to 6.0 wt-% (based on the overall weight of the heterophasic propylene copolymer), a soluble fraction (SF) determined according to Crystex analysis described in the method section in the range from 2.0 to 15.0 wt% (based on the overall weight of the heterophasic propylene copolymer), and a melt flow rate MFR2(measured according to ISO 1 133, 2.16 kg, 230°C) in the range between 0.1 and 1.0 g / 10 min; b) in the range from 10 to 60 wt% (based on the overall weight of the polyolefin composition) of a mixed-plastics polypropylene blend of recycled material (Blend A) having a polypropylene content (iPP), as determined according to IR-spectroscopy, in the range from 75.0 - 99.0 wt% (based on the total weight of the mixed-plastic polypropylene blend of recycled material), and a content of at least one or more, preferably all of the following elements (determined by X-ray fluorescence (XRF);
[0018] Fe in an amount of < 500 ppm,
[0019] Ti in an amount of < 6000 ppm,
[0020] Cu in an amount of < 100 ppm,
[0021] Pb in an amount of < 50 ppm,
[0022] Zn in amount of < 100 ppm,
[0023] (based on the total weight of the mixed-plastic polypropylene blend of recycled material); c) at least one metal deactivator, and d) optionally further additives, wherein the sum of all ingredients always adds up to 100 wt%.
[0024] Thus, a polyolefin composition is provided that contains recycled plastic material, virgin heterophasic polypropylene polymer and a metal deactivator. This combination provides a composition wherein at least a part of virgin polymer is replaced by recycled material. The addition of a metal deactivator provides a composition with excellent oxidation stability. Such compositions are applicable for pipes.
[0025] For the purposes of the present description and of the subsequent claims, the term “recycled” is used to indicate that the material is recovered from post-consumer waste and / or postindustrial waste, wherein recycled material from post-consumer waste is preferred. Namely, post-consumer waste refers to objects having completed at least a first use cycle (or life cycle), i.e. having already served their first purpose and been through the hands of a consumer; while post-industrial waste refers to the manufacturing scrap which does normally not reach a consumer. In the gist of the present invention “recycled polymers” may also comprise up to 20 wt-%, preferably up to 18 wt-%, more preferably up to 16 wt-% and even more preferably up to 14 wt-%, most preferably up to 12 wt -%, based on the overall weight of the recycled polymer of other components originating from the first use. Type and amount of these components influence the physical properties of the recycled polymer. The physical properties given below refer to the main component of the recycled polymer.
[0026] As described also further below, typical other components originating from the first use are thermoplastic polymers, like polystyrene (PS) and polyamide 6 (PA 6) , talc, chalk, ink, wood, paper, limonene and fatty acids. The content of PS and PA 6 in recycled polymers can be determined by Fourier Transform Infrared Spectroscopy (FTIR) and the content of talc, chalk, wood and paper may be measured by Thermogravimetric Analysis (TGA).
[0027] The term “virgin” denotes the newly produced materials and / or objects prior to first use and not being recycled. In case that the origin of the polymer is not explicitly mentioned the polymer is a “virgin” polymer.
[0028] It is to be understood that the material used for Crystex analysis is based on material without any additives such as fillers, pigments, non-soluble polymers e.g. PET, etc. (see also details to Crystex analysis in the method section), i.e. only material that can be dissolved in 1 , 2, 4, tricholorbenzene at 170°C is used for Crystex analysis. Any non-dissolved material is removed.
[0029] It is further to be understood that none of the following compounds is added to the (final) polyolefin composition: any metal sulphide, in particular Zn sulphide, any spiro compounds (such as described in US 4,963,605), any inorganic or organic base used as neutralizer, any HALS UV stabilizer and 2,2-bis(hydroxymethyl)-1 ,2-propanediol. Thus, the present polyolefin composition does essentaily not contain and is preferably free of any metal sulphide, in particular Zn sulphide, any spiro compounds (such as described in US 4,963,605), any inorganic or organic base used as neutralizer, any HALS UV stabilizer and 2,2- bis(hydroxymethyl)-1 ,2-propanediol.
[0030] The ingredients of the present polyolefin composition will be described now in more detail. virgin oolvmer (HECO)
[0031] A heterophasic propylene copolymer comprises a matrix (M) being a (semicrystalline) polypropylene and an elastomeric propylene copolymer (EPC). The expression "heterophasic propylene copolymer" or "heterophasic" as used in the present invention indicates that the elastomeric propylene copolymer is (finely) dispersed in the (semicrystalline) polypropylene.
[0032] In other words, the (semicrystalline) polypropylene constitutes a matrix in which the elastomeric propylene copolymer forms inclusions in the matrix, i.e. in the (semicrystalline) polypropylene. Thus, the matrix contains (finely) dispersed inclusions being not part of the matrix and said inclusions contain the elastomeric propylene copolymer. The term "inclusion" according to this invention shall preferably indicate that the matrix and the inclusion form different phases within the heterophasic propylene copolymer (HECO), said inclusions are for instance visible by high resolution microscopy, like electron microscopy or atomic force microscopy. The heterophasic propylene copolymer (HECO) according to this invention has a rather high molecular weight and rather low amount of rubber, i.e. of the elastomeric propylene copolymer. In one embodiment, the at least one heterophasic propylene copolymer (HECO) comprises a propylene homopolymer (PPH) as (semicrystalline) matrix and a propylene-ethylene rubber as elastomeric propylene copolymer (EPC).
[0033] The polypropylene matrix (M) is preferably a random propylene copolymer or a propylene homopolymer, the latter being especially preferred. The expression “propylene homopolymer relates to a polypropylene that consists of more than 99.5 wt%, preferably of more than or at least of 99.7 wt% of propylene units. In a preferred embodiment only propylene units are detectable in the propylene homopolymer.
[0034] The elastomeric propylene copolymer (EPC) comprises units derived from propylene and ethylene and / or C4 to C20 alpha-olefins, more preferably from ethylene and / or C4 to C10 alpha-olefins and most preferably from ethylene. The heterophasic propylene copolymer (HECO) can contain typical additives known in the art, like antioxidants or process additives. It is especially preferred that the heterophasic propylene copolymer (HECO) is alpha-nucleated, i.e. contains an alpha-nucleating agent.
[0035] The alpha-nucleating agent is preferably selected from the group consisting of
[0036] (i) salts of monocarboxylic acids and polycarboxylic acids, e.g. sodium benzoate or aluminum tert-butylbenzoate, and
[0037] (ii) dibenzylidenesorbitol (e.g. 1 ,3 : 2,4 dibenzylidenesorbitol) and C1 -C8-alkylsubstituted dibenzylidenesorbitol derivatives, such as methyldibenzylidenesorbitol, ethyldibenzylidenesorbitol or dimethyldibenzylidenesorbitol (e.g. 1 ,3 2,4 di(methylbenzylidene) sorbitol), or substituted nonitol-derivatives, such as 1 ,2, 3, -trideoxy 4,6:5,7-bis-0-[(4-propylphenyl) methylene]-nonitol, and
[0038] (iii) salts of diesters of phosphoric acid, e.g. sodium 2,2’-methylenebis (4,6-di-tert-butylphenyl) phosphate or aluminum- hydroxy-bis[2,2’-methylene-bis(4,6-di-t-butylphenyl)phosphate], and
[0039] (iv) vinylcycloalkane polymer or vinylalkane polymer, and
[0040] (v) mixtures thereof.
[0041] The at least one heterophasic propylene copolymer (HECO) may have a melt flow rate MFR2(measured according to ISO 1133, 2.16 kg, 230°C) in the range from 0.1 to 0.9 g / 10 min, preferably from 0.13 to 0.7 g / 10min, more preferably from 0.15 to 0.5 g / 10min.
[0042] The at least one heterophasic propylene copolymer (HECO) has in the Crystex analysis one or more, preferably all of the following properties: a total ethylene (C2) content in the range of 0.5 to less than 5.5 wt.-%, preferably from 0.8 to 5.3 wt%, more preferably from 1 .0 to 5.2 wt%, even more preferably from 1 .0 to less than 4.5 wt.-%, preferably from 1 .0 to 4.3 wt%, more preferably from 1 .3 to 4.2 wt% (based on the total weight of the heterophasic propylene copolymer). an intrinsic viscosity (IV) in the range from 1 .0 to 6.0 dl / g, preferably in the range from 2.0 to 5.5 dl / g, more preferably in the range from 3.0 to 5.0 dl / g, and / or a crystalline fraction (CF) having one or more, preferably all of the following properties: an ethylene content (C2(CF)) in the range from 0.3 to 5.0 wt.-% (based on the total weight of the crystalline fraction), preferably from 0.4 to 3.0 wt%, more preferably from 0.5 to 2.0 wt%. an intrinsic viscosity (IV(CF)) in the range from 2.0 to 6.0 dl / g, preferably in the range from 2.5 to 5.5 dl / g, more preferably in the range from 3.0 to 5.0 dl / g. and / or a soluble fraction (SF) content in the range of 2.5 to 14.5 wt%, preferably in the range of 3.0 to 13.0 wt%, more preferably in the range of 3.5 to 1 1 .5 wt% (based on the total weight of the heterophasic propylene copolymer); the soluble fraction (SF) having one or more, preferably all of the following properties: an ethylene content (C2(SF)) in the range from 15.0 to 40.0 wt.-% (based on the total weight of the soluble fraction), preferably from 20.0 to 35.0 wt%, more preferably from 20.0 to 33.0 wt%. an intrinsic viscosity (IV(SF)) in the range from 1.0 to 6.0 dl / g, preferably in the range from 1 .5 to 5.0 dl / g, more preferably in the range from 2.0 to 4.0 dl / g.
[0043] The at least one heterophasic propylene copolymer (HECO) has an impact strength (ISO179- 1 , Charpy notched 1 eA +23°C, measured as described in the method section) of at least 8 kJ / m2, preferably at least 10 kJ / m2, in particular in a range from 8.0 to 80.0 kJ / m2, more particular in a range from 10.0 to 70.0 kJ / m2, even more particular in a range from 10.0 to 60.0 kJ / m2.
[0044] The at least one heterophasic propylene copolymer (HECO) may have an impact strength (ISO179-1 , Charpy notched 1 eA -20°C, measured as described in the method section) of at least 1 .0 kJ / m2, preferably at least 1 .5 kJ / m2, more preferably of at least 2.0 kJ / m2, in particular in a range from 1 .0 to 5.0 kJ / m2, more particular in a range from 1 .5 to 4.5 kJ / m2, even more particular in a range from 2.0 to 4.0 kJ / m2.
[0045] Preferred heterophasic copolymers are described now in more detail.
[0046] The at least one heterophasic propylene copolymer (HECO-1 ) has in the Crystex analysis one or more, preferably all of the following properties: a total ethylene (C2) content from 0.5 to less than 4.0 wt.-%, preferably from 1 .0 to 3.5 wt%, more preferably from 1 .2 to 3.0 wt%, such as from 1 .2 to 2.5 wt% (based on the total weight of the heterophasic propylene copolymer), and / or an intrinsic viscosity (IV) in the range from 1 .0 to 6.0 dl / g, preferably in the range from 2.0 to 5.5 dl / g, more preferably in the range from 3.0 to 5.0 dl / g, and / or a crystalline fraction (CF) having one or more, preferably all of the following properties: an ethylene content (C2(CF)) in the range from 0.3 to 3.0 wt.-% (based on the total weight of the crystalline fraction), preferably from 0.4 to 2.0 wt%, more preferably from 0.5 to 1 .5 wt%. an intrinsic viscosity (IV(CF)) in the range from 2.0 to 6.0 dl / g, preferably in the range from 2.5 to 5.5 dl / g, more preferably in the range from 3.0 to 5.0 dl / g. and / or a soluble fraction (SF) content in the range of 2.5 to 9.5 wt%, preferably in the range of 3.0 to 8.5 wt%, more preferably in the range of 3.5 to 7.5 wt% (based on the total weight of the heterophasic propylene copolymer) the soluble fraction (SF) having one or more, preferably all of the following properties: an ethylene content (C2(SF)) in the range from 15.0 to 35.0 wt.-% (based on the total weight of the soluble fraction), preferably from 18.0 to 30.0 wt%, more preferably from 20.0 to 25.0 wt%. an intrinsic viscosity (IV(SF)) in the range from 1.0 to 6.0 dl / g, preferably in the range from 1 .5 to 5.0 dl / g, more preferably in the range from 2.0 to 4.0 dl / g.
[0047] The at least one heterophasic propylene copolymer (HECO-1 ) may have a melt flow rate MFR2(measured according to ISO 1 133, 2.16 kg, 230°C) in the range from 0.1 and 0.9 g / 10 min, preferably from 0.13 to 0.7 g / 10min, more preferably from 0.15 to 0.4 g / 10min.
[0048] The least one heterophasic propylene copolymer (HECO-1 ) may have an impact strength (ISO179-1 , Charpy notched 1 eA +23°C, measured as described in the method section) of at least 8 kJ / m2, preferably at least 10 kJ / m2, in particular in a range from 8.0 to 50.0 kJ / m2, more particular in a range from 10.0 to 40.0 kJ / m2, even more particular in a range from 10 to 35 kJ / m2. The least one heterophasic propylene copolymer (HECO-1 ) may have an impact strength (ISO179-1 , Charpy notched 1 eA -20°C, measured as described in the method section) of at least 1 .0 kJ / m2, preferably at least 1 .5 kJ / m2, more preferably of at least 2.0 kJ / m2, in particular in a range from 1 .0 to 4.0 kJ / m2, more particular in a range from 1 .5 to 3.5 kJ / m2, even more particular in a range from 2.0 to 3.0 kJ / m2.
[0049] A process for obtaining said heterophasic polypropylene copolymer HECO-1 is described in detail in the method section.
[0050] The at least one heterophasic propylene copolymer (HECO-2) has in the Crystex analysis one or more, preferably all of the following properties: a total ethylene (C2) content from 1 .5 to less than 5.5 wt.-%, preferably from 2.0 to 5.2 wt%, more preferably from 2.5 to 5.0 wt%, such as from 3.0 to 4.8 wt% (based on the total weight of the heterophasic propylene copolymer) an intrinsic viscosity (IV) in the range from 1 .0 to 6.0 dl / g, preferably in the range from 2.0 to 5.5 dl / g, more preferably in the range from 3.0 to 5.0 dl / g, and / or a crystalline fraction (CF) having one or more, preferably all of the following properties: an ethylene content (C2(CF)) in the range from 0.5 to 5.0 wt.-% (based on the total weight of the crystalline fraction), preferably from 1 .0 to 3.0 wt%, more preferably from 1 .2 to 2.0 wt%. an intrinsic viscosity (IV(CF)) in the range from 2.0 to 6.0 dl / g, preferably in the range from 2.5 to 5.5 dl / g, more preferably in the range from 3.0 to 5.0 dl / g, and / or a soluble fraction (SF) content in the range of 4.0 to 14.5 wt%, preferably in the range of 5.0 to 13.0 wt%, more preferably in the range of 6.0 to 1 1 .5 wt% (based on the total weight of the heterophasic propylene copolymer); the soluble fraction (SF) having one or more, preferably all of the following properties: an ethylene content (C2(SF)) in the range from 20.0 to 40.0 wt.-% (based on the total weight of the soluble fraction), preferably from 25.0 to 35.0 wt%, more preferably from 30.0 to 33.0 wt%. an intrinsic viscosity (IV(SF)) in the range from 1.0 to 6.0 dl / g, preferably in the range from 1 .5 to 5.0 dl / g, more preferably in the range from 2.0 to 4.0 dl / g.
[0051] The at least one heterophasic propylene copolymer (HECO-2) has a melt flow rate MFR2(measured according to ISO 1133, 2.16 kg, 230°C) in the range from 0.1 to 0.9 g / 10 min, preferably from 0.13 to 0.7 g / 10min, more preferably from 0.15 to 0.4 g / 10min.
[0052] The at least one heterophasic propylene copolymer (HECO-2) has an impact strength (ISO179-1 , Charpy notched 1 eA +23°C, measured as described in the method section) of at least 20 kJ / m2, preferably at least 25 kJ / m2, more preferably of at least 30 kJ / m2, in particular in a range from 20.0 to 80.0 kJ / m2, more particular in a range from 25.0 to 70.0 kJ / m2, even more particular in a range from 30.0 to 60.0 kJ / m2.
[0053] The at least one heterophasic propylene copolymer (HECO-2) has an impact strength (ISO179-1 , Charpy notched 1 eA -20°C, measured as described in the method section) of at least 1 .5 kJ / m2, preferably at least 2.0 kJ / m2, more preferably of at least 2.5 kJ / m2, in particular in a range from 1 .5 to 5.0 kJ / m2, more particular in a range from 2.0 to 4.5 kJ / m2, even more particular in a range from 2.5 to 4.0 kJ / m2.
[0054] A process for obtaining said heterophasic polypropylene copolymer HECO-2 is described in detail in the method section.
[0055] Mixed-i blend of recycled material
[0056] The mixed-plastics polypropylene blend is obtained from recycled waste stream of recycled post-consumer waste.
[0057] In one aspect the recyclate blend may be a polypropylene (PP) rich material of recycled plastic material that comprises significantly more polypropylene than polyethylene. The PP rich material may be obtained by selective processing, degassing and filtration and / or by separation according to type and colors such as NIR or Raman sorting and VIS sorting. In an embodiment, the mixed-plastics polypropylene blend of recycled material (Blend A) has a polypropylene content (iPP) in the range from 80.0 to 98.0 wt%, preferably in the range from 85.0 to 97.0 wt%, more preferably from 88.0 to 95.0 wt% (based on the total weight of the recyclate blend) determined according to IR method as described in the method section. The recyclate may be recovered from a waste plastic material derived from post-consumer and / or post-industrial waste.
[0058] In still a further embodiment, the mixed-plastics polypropylene blend of recycled material (Blend A) has in the Crystex analysis one or more, preferably all of the following properties: a total ethylene (C2) content in the range from 1.0 to 20.0 wt.-%, preferably from 2.0 to 18.0 wt%, more preferably from 5.0 to 15.0 wt%, even more preferably from 5.5 to 13.0 wt% (based on the total weight of the mixed-plastic polypropylene blend of recycled material), and / or an intrinsic viscosity (IV) in the range from 1 .0 to 3.0 dl / g, preferably in the range from 1 .2 to 2.7 dl / g, more preferably in the range from 1 .5 to 2.5 dl / g, and / or a crystalline fraction (CF) having one or more, preferably all of the following properties: an ethylene content (C2(CF)) in the range from 1 .0 to 20.0 wt.-% (based on the total weight of the crystalline fraction), preferably from 2.0 to 18.0 wt%, more preferably from 3.0 to 15.0 wt%, even more preferably from 4.0 to 13.0 wt%, . an intrinsic viscosity (IV(CF)) in the range from 1.0 to 3.0 dl / g, preferably in the range from 1 .2 to 2.7 dl / g, more preferably in the range from 1 .5 to 2.5 dl / g, and / or a soluble fraction (SF) in the range from more than 2.0 to 20.0 wt%, preferably in the range from 2.5 to 18.0 wt%, preferably in a range from more than 3.0.0 to 17.0 wt%, more preferably in a range from more than 3.0 to 15.0 wt%, even more preferably in a range from more than 3.5.to 15.0 wt%, still more preferably in a range from more than 3.5.to 12.0 wt% (based on the total weight of the mixed-plastic polypropylene blend of recycled material), the soluble fraction (SF), having one or more, preferably all of the following properties if determinable,: an ethylene content (C2(SF)) in the range from 0.01 to 40.0 wt.-% (based on the total weight of the soluble fraction), preferably from 0.1 to 35.0 wt%, more preferably from 0.5 to 32.0 wt%, even more preferably from 1 .0 to 32.0 wt%, even more preferably from 2.0 to 32.0 wt%, even more preferably from 3.0 to 30.0 wt%, even more preferably from 4.0 to 30.0 wt%, even more preferably from 5.0 to 30.0 wt%. an intrinsic viscosity (IV(SF)) in the range from 0.2 to 3.5 dl / g, preferably in the range from 0.3 to 3.2 dl / g, more preferably in the range from 0.4 to 2.7 dl / g, even more preferably in the range from 0.5 to 2.5 dl /
[0059] The mixed-plastics polypropylene blend of recycled material (Blend A) has an ash content of at most 7.0 wt%, preferably of at most 6.0 wt%, more preferably of at most 5.0 wt% (based on the overall weight of the recyclate blend), such as in the range from 0.5 to 7.0 wt%, preferably from 0.7 to 6.0 wt%, more preferably from 0.8 to 5.0 wt%, such as 1 .0 to 3.5 wt%
[0060] In an embodiment, the mixed-plastics polypropylene blend of recycled material (Blend A) has a melt flow rate (ISO1133, 2.16kg; 230°C) of in the range between 1.0 and 25.0 g / 10 min, preferably between 1 .5 and 22.0 g / 10min, more preferably between 2.0 and 21 .0 g / 10min.
[0061] In a further embodiment, the mixed-plastics polypropylene blend of recycled material (Blend A) comprises a content of one or more, preferably all of the following elements (as determined by X-ray fluorescence XRF described in the method section):
[0062] Fe in an amount of < 500 ppm, preferably < 400 ppm, more preferably < 350 ppm, such as in a range of from 10 to 500 ppm, preferably of from 25 to 400 ppm, more preferably of from 50 to 350 ppm
[0063] Ti in an amount of < 6000 ppm, preferably < 5500 ppm, more preferably of < 5000 ppm, such as in a range of from 10 to 6000 ppm, preferably of from 100 to 6000 ppm, more preferably of from 250 to 6000 ppm.
[0064] Cu in an amount of < 100 ppm, preferably < 80 ppm, more preferably < 50 ppm, such as in a range of from not detected to 100 ppm, preferably of from not detected to 80 ppm, more preferably of from not detected to 50 ppm
[0065] Pb in an amount of < 50 ppm, preferably < 35 ppm, more preferably < 25 ppm, such as in a range of from 1 to 50 ppm, preferably of from 2 to 35 ppm, more preferably of from 5 to 25 ppm;
[0066] Zn in amount of < 100 ppm, preferably < 80 ppm, more preferably < 75 ppm, such as in a range of from 10 to 100 ppm, preferably of from 15 to 80 ppm, more preferably of from 20 to 75 ppm
[0067] Further elements may be one or more of the following: Al in an amount of < 400 ppm, preferably < 300 ppm, more preferably < 250 ppm; such as in a range of from 10 to 400 ppm, preferably of from 15 to 300 ppm, more preferably of from 20 to 250 ppm,
[0068] Ca in an amount of < 40000 ppm, preferably < 30000 ppm, more preferably < 20000 ppm; such as in a range of from 100 to 40000 ppm, preferably of from 100 to 30000 ppm, more preferably of from 200 to 20000 ppm,
[0069] Cr in an amount of < 30 ppm, preferably < 20 ppm, more preferably < 10 ppm; and / or such as in a range of from not detected to 30 ppm, preferably of from not detected to 20 ppm, more preferably of from not detected to 10 ppm,
[0070] Mg in an amount of < 1000 ppm, preferably < 800 ppm, more preferably < 700 ppm; such as in a range of from 10 to 1000 ppm, preferably of from 20 to 800 ppm, more preferably of from 25 to 700 ppm
[0071] In a preferred embodiment, the mixed-plastics polypropylene blend of recycled material (Blend A) has one or more, preferably all of the following properties: an OCS gel index (determined as described in the method section)) of less than 65.000, preferably of less than 60.000, more preferably of less than 30.000, even more preferably of less than 20.000, such as from 500 to less than 65000, in particular from 800 to less than 60.000, more in particular from 1000 to less than 30.000, even more in particular from 1500 to less than 20.000, such as from 1700 to 15.000, preferably from 1800 to 10.000, more preferably from 2000 to 9000, even more preferably from 2000 to 8000, an OCS others (> 1000 pm, determined as described in the method section) of less than 1500 1 / m2, preferably of less than 1300 1 / m2, more preferably of less than 1000 1 / m2, even more preferably of less than 800 1 / m2, such as in a range from 0.1 to less than 1500 1 / m2, preferably in range from 0.5 to less than 1300 1 / m2, more preferably in a range from 5.0 to less than 1000 1 / m2, even more preferably in a range from 10.0 to less than 800 1 / m2, still more preferably in a range from 15.0 to less than 750 1 / m2, an OCS contaminations (>1000 pm, determined as described in the method section) of less than 85 1 / m2, preferably of less than 80 1 / m2, more preferably of less than 70 1 / m2, even more preferably of less than 60 1 / m2, such as in a range from 0.1 to less than 85 1 / m2, preferably in range from 0.5 to less than 80 1 / m2, more preferably in a range from 1.0 to less than 75 1 / m2, even more preferably in a range from 1.0 to less than 70 1 / m2, still more preferably in a range from 1 .0 to less than 65 1 / m2, such as in a range from 1 .0 to 60.0 1 / m2, in particular in a range from 1 .0 to 50.0 1 / m2, an OCS gel (>1000 pm, determined as described in the method section ) of less than 300 1 / m2, preferably of less than 200 1 / m2, more preferably of less than 150 1 / m2, even more preferably of less than 100 1 / m2, such as in a range from 0.1 to less than 300 1 / m2, preferably in range from 0.2 to less than 200 1 / m2, more preferably in a range from 0.5 to less than 150 1 / m2, even more preferably in a range from 0.6 to less than 100 1 / m2, still more preferably in a range from 1 .0 to less than 50 1 / m2, such as in a range from 1.1 to 40 1 / m2.
[0072] In another embodiment the mixed-plastics polypropylene blend of recycled material comprises further components selected from the group comprising polystyrene, stabilizers, polyamide, talc, chalk, paper, wood, limonene, fatty acid and mixtures thereof, in particular polystyrene, polyamide-6 as determined by FTIR, limonene as determined by using solid phase microextraction (HS-SPME-GC-MS)
[0073] Due to the recycling origin, the blend may contain: organic fillers, and / or inorganic fillers, and / or additives in amounts of up to 10 wt%, preferably up to 7 wt%, more preferably up to 4 wt% with respect to the weight of the recyclate blend.
[0074] As stated above, the recyclate blend (Blend A) may include one or more further components, selected from:
[0075] - up to 3.0 wt%, preferably up to 2.0 wt% of polystyrene and / or copolymers such as ABS,
[0076] - up to 3.0 wt% stabilizers, preferably up to 2.0 wt% stabilizers,
[0077] - up to 4.0 wt% polyamide, preferably up to 2.0 wt% polyamide,
[0078] - up to 3.0 wt% talc, preferably up to 1 .0 wt% talc,
[0079] - up to 1 .0 wt% paper, preferably up to 0.5 wt% paper,
[0080] - up to 1 .0 wt% wood, preferably up to 0.5 wt% wood, and
[0081] - 0.1 ppm - 100 ppm of limonene as determined by using solid phase microextraction (HS-SPME-GC-MS), and
[0082] - 0 - 200 ppm total fatty acid content as determined by using solid phase microextraction (HS-SPME-GC-MS), wherein all amounts are given with respect to the total weight of the recyclate blend.
[0083] The properties of a preferred polypropylene recyclate blend that may be used is now described. Blend A-1
[0084] The mixed-plastics polypropylene blend of recycled material (Blend A-1 ) has an iPP content of 75 to 97 wt%, preferably of 80-95 wt%, more preferably of 85 - 93 wt% (based on the total weight of the recyclate blend) determined according to IR method as described in the method section.
[0085] Furthermore, the preferred mixed-plastics polypropylene blend of recycled material (Blend A- 1 ) has in the Crystex analysis one or more, preferably all of the following properties: a total ethylene (C2) content in the range from 1 .0 to 20.0 wt.-%, preferably from 2.0 to 15.0 wt%, more preferably from 5.0 to 13.0 wt%, even more preferably from 9.0 to 12.0 wt% (based on the total weight of the mixed-plastic polypropylene blend of recycled material), and / or an intrinsic viscosity (IV) in the range from 1 .0 to 3.0 dl / g, preferably in the range from 1 .2 to 2.5 dl / g, more preferably in the range from 1 .5 to 2.0 dl / g, and / or a crystalline fraction (CF) having one or more, preferably all of the following properties: an ethylene content (C2(CF)) in the range from 1.0 to 20.0 wt.-%, preferably from 2.0 to 15.0 wt%, more preferably from 5.0 to 13.0 wt%, even more preferably from 8.0 to 12.0 wt %; and / or an intrinsic viscosity (IV(CF)) in the range from 1.0 to 3.0 dl / g, preferably in the range from 1 .2 to 2.5 dl / g, more preferably in the range from 1 .5 to 2.0 dl / g, a soluble fraction (SF) in the range from 8.0 to 20.0 wt%, preferably in a range from 8.5 to 17.0 wt%, more preferably in a range from 9.0 to 15.0 wt%, even more preferably in a range from 10.0 to 13.0 wt%, such as from 10.0 to 12.0 wt% (based on the total weight of the mixed- plastic polypropylene blend of recycled material), the soluble fraction (SF) having one or more, preferably all of the following properties: an ethylene content (C2(SF)) in the range from 15.0 to 40.0 wt.-% (based on the total weight of the soluble fraction), preferably from 20.0 to 35.0 wt%, more preferably from 25.0 to 32.0 wt%. an intrinsic viscosity (IV(SF)) in the range from 0.5 to 3.0 dl / g, preferably in the range from 0.8 to 2.5 dl / g, more preferably in the range from 1 .0 to 2.0 dl / g The preferred mixed-plastics polypropylene blend of recycled material (Blend A-1 ) has further an ash content of at most 5.0 wt%, preferably of at most 4.0 wt%, more preferably of at most 3.0 wt% (based on the overall weight of the recyclate blend), such as in the range from 0.5 to 5.0 wt%, preferably from 0.7 to 4.0 wt%, more preferably from 0.8 to 3.0 wt%, such as 1 .0 to 2.0 wt%.
[0086] In an embodiment, the mixed-plastics polypropylene blend of recycled material (Blend A-1 ) has a melt flow rate (ISO1133, 2.16kg; 230°C) in the range between 10.0 and 25.0 g / 10 min , preferably between 12.0 and 20.0 g / 10min, more preferably between 14.0 and 18.0 g / 10min,
[0087] In a further embodiment, the mixed-plastics polypropylene blend of recycled material (Blend A1 ) comprises a content of one or more, preferably all of the following elements (as determined by X-ray fluorescence XRF described in the method section):
[0088] Fe in an amount of < 500 ppm, preferably < 400 ppm, more preferably < 350 ppm, such as in a range of from 10 to 500 ppm, preferably of from 25 to 400 ppm, more preferably of from 50 to 350 ppm;
[0089] Ti in an amount of < 6000 ppm, preferably < 5500 ppm, more preferably of < 5000 ppm, such as in a range of from 10 to 6000 ppm, preferably of from 100 to 6000 ppm, more preferably of from 250 to 6000 ppm,
[0090] Cu in an amount of < 80 ppm, preferably < 50 ppm, more preferably < 40 ppm, such as in a range of from 5 to 80 ppm, preferably of from 8 to 50 ppm, more preferably of from 10 to 40 ppm;
[0091] Pb in an amount of < 30 ppm, preferably < 20 ppm, more preferably < 15 ppm, such as in a range of from 1 to 30 ppm, preferably of from 2 to 20 ppm, more preferably of from 5 to 15 ppm;
[0092] Zn in amount of < 100 ppm, preferably < 80 ppm, more preferably < 75 ppm, such as in a range of from 20 to 100 ppm, preferably of from 30 to 80 ppm, more preferably of from 40 to 75 ppm.
[0093] In a preferred embodiment, the mixed-plastics polypropylene blend of recycled material (Blend A-1 ) has one or more, preferably all of the following properties: an OCS gel index (determined as described in the method section)) of less than 60.000, such as from 20,000 to less than 65,000, in particular from 30,000 to less than 60,000, an OCS others (> 1000 pm, determined as described in the method section) of less than 1500 1 / m2, preferably of less than 1300 1 / m2, more preferably of less than 1000 1 / m2, even more preferably of less than 800 1 / m2, such as in a range from 100.0 to less than 1500 1 / m2, preferably in range from 200.0 to less than 1300 1 / m2, more preferably in a range from 300.0 to less than 1000 1 / m2, even more preferably in a range from 400.0 to less than 800 1 / m2, still more preferably in a range from 500.0 to less than 750 1 / m2, an OCS contaminations (>1000 pm, determined as described in the method section) of less than 80 1 / m2, preferably of less than 70 1 / m2, more preferably of less than 60 1 / m2, even more preferably of less than 50 1 / m2, such as in a range from 5.0 to less than 85 1 / m2, preferably in range from 10.0 to less than 80 1 / m2, more preferably in a range from 15.0 to less than 75 1 / m2, even more preferably in a range from 20.0 to less than 70 1 / m2, still more preferably in a range from 25.0 to less than 65 1 / m2, such as in a range from 30.0 to 60.0 1 / m2, in particular in a range from 35.0 to 50.0 1 / m2, an OCS gel (>1000 pm, determined as described in the method section ) of less than 200 1 / m2, preferably of less than 150 1 / m2, more preferably of less than 100 1 / m2, even more preferably of less than 50 1 / m2, such as in a range from 5.0 to less than 300 1 / m2, preferably in range from 10.0 to less than 200 1 / m2, more preferably in a range from 15.0 to less than 150 1 / m2, even more preferably in a range from 20.0 to less than 100 1 / m2, still more preferably in a range from 25.0 to less than 50 1 / m2, such as in a range from 30.0 to 45 1 / m2.
[0094] Blend A-1 can be produced by extrusion of processed rigid packaging waste with fine melt filtration of 50 - 150 pm, preferably 80 - 120, even more preferably 90-110 pm, such as 100 pm. It is obtainable for example from mtm plastics GmbH (Germany) Blend A-2
[0095] In an embodiment, the mixed-plastics polypropylene blend of recycled material (Blend A-2) has a polypropylene content (iPP) in the range from 80.0 to 99.0 wt%, 85.0 to 98.0 wt%, preferably in the range from 90.0 to 97.0 wt%, more preferably from 92.0 to 95.0 wt% (based on the total weight of the recylate blend) determined according to IR method as described in the method section.
[0096] In still a further embodiment, the mixed-plastics polypropylene blend of recycled material (Blend A-2) has in the Crystex analysis one or more, preferably all of the following properties: a total ethylene (C2) content in the range from 2.0 to 15.0 wt.-%, preferably from 3.0 to 12.0 wt%, more preferably from 5.0 to 10.0 wt%, even more preferably from 6.0 to 8.0 wt%, (based on the total weight of the mixed-plastic polypropylene blend of recycled material), an intrinsic viscosity (IV) in the range from 1 .0 to 3.0 dl / g, preferably in the range from 1 .2 to 2.5 dl / g, more preferably in the range from 1 .5 to 2.0 dl / g, and / or a crystalline fraction (CF) having one or more, preferably all of the following properties: a crystalline fraction (CF) having an ethylene content (C2(CF)), as determined by FT-IR spectroscopy calibrated by quantitative13C-NMR spectroscopy, in the range from 1.5 to 9.5 wt.-% (based on the total weight of the crystalline fraction), preferably from 2.0 to 7.0 wt%, more preferably from 3.0 to 5.0 wt%, an intrinsic viscosity (IV(CF), in the range from 1 .0 to 3.0 dl / g, preferably in the range from 1 .2 to 2.5 dl / g, more preferably in the range from 1 .5 to 2.0 dl / g, a soluble fraction (SF) in the range from 8.0 to 18.0 wt%, preferably in a range from 8.0 to 17.0 wt%, more preferably in a range from 8.5 to 15.0 wt%, even more preferably in a range from 9.0 to 12.0 wt%(based on the total weight of the mixed-plastic polypropylene blend of recycled material, the soluble fraction (SF) having one or more, preferably all of the following properties: an ethylene content (C2(SF)) in the range from 15.0 to 40.0 wt.-% (based on the total weight of the soluble fraction), preferably from 20.0 to 35.0 wt%, more preferably from 25.0 to 32.0 wt%. an intrinsic viscosity (IV(SF)) in the range from 0.5 to 3.0 dl / g, preferably in the range from 0.8 to 2.5 dl / g, more preferably in the range from 1 .0 to 2.0 dl / g.
[0097] The mixed-plastics polypropylene blend of recycled material (Blend A-2) has an ash content of at most 4.0 wt%, preferably of at most 3.0, more preferably of at most 2.0 wt% (based on the overall weight of the recyclate blend), such as in the range from 0.5 to 4.0 wt%, preferably from 0.7 to 3.0 wt%, more preferably from 0.8 to 2.0 wt%, such as 1 .0 to 1 .5 wt%
[0098] In an embodiment, the mixed-plastics polypropylene blend of recycled material (Blend A-2) has a melt flow rate (ISO1 133, 2.16kg; 230°C) in the range between 10 and 25 g / 10min, preferably between 15.0 and 22.0 g / 10min, more preferably between 18.0 and 21 .0 g / 10min,
[0099] In a further embodiment, the mixed-plastics polypropylene blend of recycled material (Blend A-2) comprises a content of one or more, preferably all of the following elements (as determined by X-ray fluorescence XRF described in the method section): Fe in an amount of < 400 ppm, preferably < 350 ppm, more preferably < 300 ppm, such as in a range of from 10 to 400 ppm, preferably of from 25 to 350 ppm, more preferably of from 50 to 300 ppm,
[0100] Ti in an amount of < 4000 ppm, preferably < 3500 ppm, more preferably of < 3000 ppm, such as in a range of from 10 to 4000 ppm, preferably of from 100 to 3500 ppm, more preferably of from 250 to 3000 ppm,
[0101] Cu in an amount of < 100 ppm, preferably < 80 ppm, more preferably < 50 ppm, such as in a range of from 5 to 100 ppm, preferably of from 8 to 80 ppm, more preferably of from 10 to 50 ppm;
[0102] Pb in an amount of < 50 ppm, preferably < 35 ppm, more preferably < 25 ppm, such as in a range of from 1 to 50 ppm, preferably of from 2 to 35 ppm, more preferably of from 5 to 25 ppm;
[0103] Zn in amount of < 100 ppm, preferably < 80 ppm, more preferably < 75 ppm, such as in a range of from 20 to 100 ppm, preferably of from 30 to 80 ppm, more preferably of from 40 to 75 ppm.
[0104] In a preferred embodiment, the mixed-plastics polypropylene blend of recycled material (Blend A-2) has one or more, preferably all of the following properties: an OCS gel index (determined as described in the method section) of less than 20,000, preferably of less than 15,000, more preferably of less than 10,000, such as from 1000 to less than 20,000, in particular from 2000 to less than 15,000, more in particular from 3000 to less than 10,000, even more in particular from 4000 to less than 9,000, such as from 5000 to 15,000, preferably from 6000 to 10,000, more preferably from 6000 to 9000, even more preferably from 6000 to 8000, an OCS others (> 1000 pm, determined as described in the method section) of less than 100 1 / m2, preferably of less than 80 1 / m2, more preferably of less than 60 1 / m2, even more preferably of less than 50 1 / m2, such as in a range from 5.0 to less than 100 1 / m2, preferably in range from 8.0 to less than 80 1 / m2, more preferably in a range from 10.0 to less than 60 1 / m2, even more preferably in a range from 12.0 to less than 50 1 / m2, still more preferably in a range from 15.0 to less than 30 1 / m2, an OCS contaminations (>1000 pm, determined as described in the method section) of less than 50 1 / m2, preferably of less than 40 1 / m2, more preferably of less than 30 1 / m2, even more preferably of less than 20 1 / m2, such as in a range from 1 .0 to less than 50 1 / m2, preferably in range from 1 .2 to less than 40 1 / m2, more preferably in a range from 1 .5 to less than 30 1 / m2, even more preferably in a range from 2.0 to less than 20 1 / m2, still more preferably in a range from 2.2 to less than 15 1 / m2, such as in a range from 2.5 to 10.0 1 / m2, in particular in a range 2.8 to 5.0 1 / m2, an OCS gel (>1000 gm, determined as described in the method section ) of less than 50 1 / m2, preferably of less than 40 1 / m2, more preferably of less than 30 1 / m2, even more preferably of less than 20 1 / m2, such as in a range from 3 to less than 50 1 / m2, preferably in range from 4 to less than 40 1 / m2, more preferably in a range from 5 to less than 30 1 / m2, even more preferably in a range from 6 to less than 20 1 / m2, still more preferably in a range from 7 to less than 20 1 / m2, such as in a range from 8 to 15 1 / m2.
[0105] A method for obtaining a mixed-plastics polypropylene Blend A-2 comprises the following steps: a) providing a precursor mixed plastic recycling stream (A); b) sieving the precursor mixed plastic recycling stream (A) to create a sieved mixed plastic recycling stream (B) having only articles with a longest dimension in the range from 30 to 400 mm; c) sorting the sieved mixed plastic recycling stream (B) by means of one or more optical sorters wherein the sieved mixed plastic recycling stream (B) is at least sorted by colour and optionally also by polyolefin type and / or article form, thereby generating one or more single-colour sorted polyolefin recycling stream(s) (C) and a mixed-colour sorted polyolefin recycling stream (CM), wherein each of the one or more single-colour sorted polyolefin recycling stream(s) (C) and the mixed-colour sorted polyolefin recycling stream (CM) are subjected separately to steps d) and beyond; d) shredding the sorted polyolefin recycling stream (C or preferably CM) to form a flaked polyolefin recycling stream (D); e) washing the flaked polyolefin recycling stream (D) with a first aqueous washing solution (W1 ) without the input of thermal energy, thereby generating a first suspended polyolefin recycling stream (E); f) removing at least part of the first aqueous washing solution (W1 ), preferably substantially all of the first aqueous washing solution (W1 ), from the first suspended polyolefin recycling stream (E) to obtain a first washed polyolefin recycling stream (F); g) washing the first washed polyolefin recycling stream (F) with a second aqueous washing solution (W2) thereby generating a second suspended polyolefin recycling stream (G), wherein sufficient thermal energy is introduced to the second suspended polyolefin recycling stream (G) to provide a temperature in the range from 65 to 95 °C during the washing; h) removing the second aqueous washing solution (W2) and any material not floating on the surface of the second aqueous washing solution from the second suspended polyolefin recycling stream (G) to obtain a second washed polyolefin recycling stream (H); i) drying the second washed polyolefin recycling stream (H), thereby obtaining a dried polyolefin recycling stream (I); j) optionally separating the dried polyolefin recycling stream (I) into a light fraction and a heavy fraction polyolefin recycling stream (J); k) optionally further sorting the heavy fraction polyolefin recycling stream (J) or, in the case that step j) is absent, the dried polyolefin recycling stream (I) by means of one or more optical sorters sorting for one or more target polyolefins by removing any flakes containing material other than the one or more target polyolefins, yielding a purified polyolefin recycling stream (K); l) optionally melt extruding, preferably pelletizing, the purified polyolefin recycling stream (K), preferably wherein additives (Ad) are added in the melt state, to form an extruded, preferably pelletized, recycled polyolefin product (L); and m) optionally aerating the recycled polyolefin product (L) or, in the case that step I) is absent, the purified polyolefin recycling stream (K) to remove volatile organic compounds, thereby generating an aerated recycled polyolefin product (M), being either an aerated extruded, preferably pelletized, recycled polyolefin product (M1 ) or aerated recycled polyolefin flakes (M2), wherein the order of steps I) and m) can be interchanged, such that the purified polyolefin recycling stream (K) is first aerated to form aerated recycled polyolefin flakes (M2) that are subsequently extruded to form an extruded, preferably pelletized, aerated recycled polyolefin product (M3), which is the polypropylene mixed blend A- 2 as described above. Blend A-3
[0106] The mixed-plastics polypropylene blend of recycled material (Blend A-3) has an iPP content of 75 to 95 wt%, preferably of 80-92 wt%, more preferably of 85 - 90 wt% (based on the total weight of the recyclate blend) determined according to IR method as described in the method section.
[0107] Furthermore, the preferred mixed-plastics polypropylene blend of recycled material (Blend A-
[0108] 3) has in the CRYSTEX analysis one or more, preferably all of the following properties: a total ethylene (C2) content in the range from 1 .0 to 20.0 wt.-%, preferably from 2.0 to 15.0 wt%, more preferably from 5.0 to 13.0 wt%, even more preferably from 9.0 to 12.0 wt%, even preferably from 9.0 to 1 1.5 wt% (based on the total weight of the mixed-plastic polypropylene blend of recycled material), and / or an intrinsic viscosity (IV) in the range from 1 .0 to 3.0 dl / g, preferably in the range from 1 .2 to 2.7 dl / g, more preferably in the range from 1 .5 to 2.5 dl / g; even more preferably in the range from 1 .7 to 2.2 dl / g; and / or a crystalline fraction (CF) having one or more, preferably all of the following properties: an ethylene content (C2(CF)) in the range from 1.0 to 20.0 wt.-%, preferably from 2.0 to 15.0 wt%, more preferably from 5.0 to 13.0 wt%, even more preferably from 6.0 to 12.0 wt %; even preferably from 9.0 to 11 .5 wt% based on the total weight of the crystalline fraction); and / or an intrinsic viscosity (IV(CF)), in the range from 1 .0 to 3.0 dl / g, preferably in the range from 1.2 to 2.7 dl / g, more preferably in the range from 1.5 to 2.5 dl / g; even more preferably in the range from 1 .7 to 2.2 dl / g; a soluble fraction (SF) determined according to Crystex analysis as described in the method section in the range from 2.0 to 7.0 wt%, preferably in a range from 2.5 to 6.5 wt%, more preferably in a range from 3.0 to 6.0 wt%, even more preferably in a range from 3.5 to 5.5 wt%, such as from 4.0 to 5.0 wt%.(based on the total weight of the mixed-plastic polypropylene blend of recycled material) the soluble fraction (SF) having one or more, preferably all of the following properties, if determinable: an ethylene content (C2(SF)) in the range from 0.1 to 25.0 wt.-% (based on the total weight of the soluble fraction), preferably from 4.0 to 20.0 wt%, more preferably from 5.0 to 18.0 wt%. an intrinsic viscosity (IV(SF)) in the range from 0.2 to 3.0 dl / g, preferably in the range from 0.3 to 2.5 dl / g, more preferably in the range from 0.4 to 2.0 dl / g.
[0109] The preferred mixed-plastics polypropylene blend of recycled material (Blend A-3) has further an ash content of at most 6.0 wt%, preferably of at most 5.0 wt%, more preferably of at most 4.5 wt% (based on the overall weight of the recyclate blend), such as in the range from 2.0 to 6.0 wt%, preferably from 2.5 to 5.0 wt%, more preferably from 2.8 to 4.5 wt%, such as 3.0 to
[0110] 3.5 wt%.
[0111] The preferred mixed-plastics polypropylene blend of recycled material (Blend A-3) has a melt flow rate (ISO1133, 2.16kg; 230°C) in the range between 1.0 and 12.0 g / 10 min, preferably between 1.0 and less than 9.0 g / 10 min, preferably between 1.5 and 8.0g / 10 min, more preferably between 2.0 and 7.0 g / 10min, even more preferably between 4.0 and 6.5 g / 10min, still more preferably between 5.0 and 6.4 g / 10min.
[0112] In a further embodiment, the mixed-plastics polypropylene blend of recycled material (Blend A-3) comprises a content of one or more, preferably all of the following elements (as determined by X-ray fluorescence XRF described in the method section):
[0113] Fe in an amount of < 350 ppm, preferably < 300 ppm, more preferably < 250 ppm, such as in a range of from 10 to 350 ppm, preferably of from 25 to 300 ppm, more preferably of from 50 to 250 ppm,
[0114] Ti in an amount of < 4000 ppm, preferably < 3500 ppm, more preferably of < 3000 ppm, such as in a range of from 10 to 4000 ppm, preferably of from 100 to 3500 ppm, more preferably of from 250 to 3000 ppm,
[0115] Cu in an amount of < 100 ppm, preferably < 80 ppm, more preferably < 50 ppm, such as in a range of from not detected to 100 ppm, preferably of from not detected to 80 ppm, more preferably of from no detected to 50 ppm;
[0116] Pb in an amount of < 50 ppm, preferably < 35 ppm, more preferably < 25 ppm, such as in a range of from 1 to 50 ppm, preferably of from 2 to 35 ppm, more preferably of from 5 to 25 ppm;
[0117] Zn in amount of < 100 ppm, preferably < 80 ppm, more preferably < 75 ppm, such as in a range of from 20 to 100 ppm, preferably of from 30 to 80 ppm, more preferably of from 40 to 75 ppm
[0118] Still further, the preferred mixed-plastics polypropylene blend of recycled material (Blend A-3) has one or more, preferably all of the following properties: an OCS gel index (determined as described in the method section) in a range from 500 to less than 5000, in particular from 800 to less than 4000, more in particular from 1000 to less than 3000, even more in particular from 1200 to less than 2500, such as from 1500 to less than 2500, preferably from 1800 to 2500, more preferably from 2000 to 2500, an OCS others (> 1000 pm, determined as described in the method section) of in a range from 5.0 to less than 100 1 / m2, preferably in range from 10.0 to less than 80 1 / m2, more preferably in a range from 15.0 to less than 60 1 / m2, even more preferably in a range from 20.0 to less than 50 1 / m2, still more such as in a range from 20.0 to 40 1 / m2, in particular in a range from 20.0 to 30.0 1 / m2, an OCS contaminations (>1000 pm, determined as described in the method section) in a range from 5.0 to less than 85 1 / m2, preferably in range from 10.0 to less than 80 1 / m2, more preferably in a range from 15.0 to less than 75 1 / m2, even more preferably in a range from 20.0 to less than 70 1 / m2, still more preferably in a range from 25.0 to less than 65 1 / m2, such as in a range from 30.0 to 60.0 1 / m2, in particular in a range 35.0 to 50.0 1 / m2, and / or an OCS gel (> 1000 pm, determined as described in the method section) in a range from 0.8 to less than 300 1 / m2, preferably in range from 1 .0 to less than 200 1 / m2, more preferably in a range from 1 .3 to less than 150 1 / m2, even more preferably in a range from 1 .5 to less than 100 1 / m2, still more preferably in a range from 1 .8 to less than 50 1 / m2, such as in a range from 2.0 to 4.0 1 / m2, in particular in a range from 2.0 to 3.0 1 / m2. Blend A-4
[0119] The mixed-plastics polypropylene blend of recycled material (Blend A-4) has an iPP content of 75 to 95 wt%, preferably of 80-92 wt%, more preferably of 85 - 90 wt% (based on the total weight of the recyclate blend) determined according to IR method as described in the method section.
[0120] Furthermore, the preferred mixed-plastics polypropylene blend of recycled material (Blend A- 4) has in the CRYSTEX analysis one or more, preferably all of the following properties: a total ethylene (C2) content in the range from 1 .0 to 15.0 wt.-%, preferably from 2.0 to 12.0 wt%, more preferably from 2.5 to 10.0 wt%, even more preferably from 3.0 to 8.0 wt%, even preferably from 4.0 to 7.0 wt% (based on the total weight of the mixed- plastic polypropylene blend of recycled material), and / or an intrinsic viscosity (IV) in the range from 1 .0 to 3.0 dl / g, preferably in the range from 1.2 to 2.7 dl / g, more preferably in the range from 1.5 to 2.5 dl / g; even more preferably in the range from 1 .5 to 2.0 dl / g; and / or a crystalline fraction (CF) having one or more, preferably all of the following properties: an ethylene content (C2(CF)) in the range from 1.0 to 15.0 wt.-%, preferably from 2.0 to 12.0 wt%, more preferably from 2.5 to 10.0 wt%, even more preferably from 3.0 to 8.0 wt %; even preferably from 4.0 to 7.0 wt% based on the total weight of the crystalline fraction); and / or an intrinsic viscosity (IV(CF)), in the range from 1 .0 to 3.0 dl / g, preferably in the range from 1 .2 to 2.7 dl / g, more preferably in the range from 1 .5 to 2.5 dl / g; even more preferably in the range from 1 .5 to 2.0 dl / g; a soluble fraction (SF) determined according to Crystex analysis as described in the method section in the range from 2.0 to 7.0 wt%, preferably in a range from 2.5 to 6.5 wt%, more preferably in a range from 3.0 to 6.0 wt%, even more preferably in a range from 3.5 to 5.5 wt%, such as from 4.0 to 5.0 wt%.(based on the total weight of the mixed-plastic polypropylene blend of recycled material) the soluble fraction (SF) having one or more, preferably all of the following properties: an ethylene content (C2(SF)) in the range from 0.1 to 20.0 wt.-% (based on the total weight of the soluble fraction), preferably from 1.0 to 15.0 wt%, more preferably from 1 .5 to 5.0 wt%, even more preferably from 2.0 to 5.0 wt%. an intrinsic viscosity (IV(SF)) in the range from 0.5 to 3.0 dl / g, preferably in the range from 0.8 to 2.5 dl / g, more preferably in the range from 1 .0 to 2.5 dl / g.
[0121] The preferred mixed-plastics polypropylene blend of recycled material (Blend A-4) has further an ash content of at most 6.0 wt%, preferably of at most 5.0 wt%, more preferably of at most
[0122] 4.5 wt% (based on the overall weight of the recyclate blend), such as in the range from 2.0 to 6.0 wt%, preferably from 2.5 to 5.0 wt%, more preferably from 2.8 to 4.5 wt%, such as 3.0 to
[0123] 3.5 wt%
[0124] The preferred mixed-plastics polypropylene blend of recycled material (Blend A-4) has a melt flow rate (ISO1133, 2.16kg; 230°C) in the range from 1.0 to 12.0 g / 10 min, preferably from 1 .0 to less than 9.0 g / 10 min, preferably from 1 .5 to 8.0 g / 10 min, more preferably from 2.0 to 7.0 g / 1 Omin, even more preferably from 4.0 to 6.5 g / 1 Omin, still more preferably from 5.0 to 6.4 g / 10min.
[0125] In a further embodiment, the mixed-plastics polypropylene blend of recycled material (Blend A-4) comprises a content of one or more, preferably all of the following elements (as determined by X-ray fluorescence XRF described in the method section):
[0126] Fe in an amount of < 350 ppm, preferably < 300 ppm, more preferably < 250 ppm, such as in a range of from 10 to 350 ppm, preferably of from 25 to 300 ppm, more preferably of from 50 to 250 ppm, Ti in an amount of < 4000 ppm, preferably < 3500 ppm, more preferably of < 3000 ppm, such as in a range of from 10 to 4000 ppm, preferably of from 100 to 3500 ppm, more preferably of from 250 to 3000 ppm,
[0127] Cu in an amount of < 100 ppm, preferably < 80 ppm, more preferably < 50 ppm, such as in a range of from 5 to 100 ppm, preferably of from 8 to 80 ppm, more preferably of from 10 to 50 ppm;
[0128] Pb in an amount of < 50 ppm, preferably < 35 ppm, more preferably < 25 ppm, such as in a range of from 1 to 50 ppm, preferably of from 2 to 35 ppm, more preferably of from 5 to 25 ppm;
[0129] Zn in amount of < 100 ppm, preferably < 80 ppm, more preferably < 75 ppm, such as in a range of from 20 to 100 ppm, preferably of from 30 to 80 ppm, more preferably of from 40 to 75 ppm.
[0130] Still further, the preferred mixed-plastics polypropylene blend of recycled material (Blend A-4) has one or more, preferably all of the following properties: an OCS gel index (determined as described in the method section) in a range from 500 to less than 5000, in particular from 800 to less than 4500, more in particular from 1000 to less than 4000, even more in particular from 1200 to less than 3800, such as from 1500 to less than 3700, preferably from 1800 to 3600, more preferably from 2000 to 3500, an OCS others (> 1000 pm, determined as described in the method section) of in a range from 0.2 to less than 15 1 / m2, preferably in range from 0.4 to less than 10 1 / m2, more preferably in a range from 0.5 to less than 8 1 / m2, even more preferably in a range from 0.6 to less than 5 1 / m2, still more such as in a range from 0.65 to 3 1 / m2, in particular in a range from 0.7 to 1.0 1 / m2, an OCS contaminations (>1000 pm, determined as described in the method section) in a range from 0.1 to less than 15 1 / m2, preferably in range from 0.2 to less than 10 1 / m2, more preferably in a range from 0.25 to less than 8 1 / m2, even more preferably in a range from 0.3 to less than 5 1 / m2, still more preferably in a range from 0.35 to less than 3 1 / m2, such as in a range from 0.4 to 2.0 1 / m2, in particular in a range from 0.45 to 1 .0 1 / m2, and / or an OCS gel (> 1000 pm, determined as described in the method section) in a range from 0.1 to less than 15 1 / m2, preferably in range from 0.2 to less than 10 1 / m2, more preferably in a range from 0.3 to less than 8 1 / m2, even more preferably in a range from 0.4 to less than 5 1 / m2, still more preferably in a range from 0.45 to less than 3 1 / m2, such as in a range from 0.5 to 2.0 1 / m2, in particular in a range from 0.55 to 1 .0 1 / m2. Metal deactivator
[0131] As mentioned above, the polyolefin composition may contain at least one metal deactivator. Adding at least one metal deactivator significantly improves the oxidation induction time (OIT) of the polyolefin composition.
[0132] In an embodiment, the at least one metal deactivator is selected from one of the following compounds:
[0133] - an alkyl hydroxyphenylalkanoyl hydrazine according to general formulae (I)
[0134] Wherein
[0135] R1, R1”, R2’, R2’’ are a C1 -C8 alkyl moiety, preferably a C1 -C4 alkyl moiety, more preferably a C3-C4 alkyl moiety, such as tert-C4 alkyl,
[0136] Wherein R1, R1”, R2’ and R2”can be the same or different, and
[0137] R3, R4are hydrogen or a C1 -C8 alkyl moiety, preferably hydrogen or a C1 -C6 alkyl moiety, such as C1 -C4 alkyl, more preferably hydrogen
[0138] Wherein R3 and R4 can be the same or different,
[0139] And / or
[0140] - a substituted aromatic carboxylic acid ester compound, preferably an aromatic carboxylic acid ester compound comprising an oxamide linkage, in particular any compound which is derived from an alkyl-substituted hydroxyphenyl carboxylic acid ester compound according to general formulae (II)
[0141] Wherein
[0142] R1, R2are a C1-C8 alkyl moiety, preferably a C1 -C4 alkyl moiety, more preferably a C3-C4 alkyl moiety, such as tert-C4 alkyl,
[0143] Wherein R1and R2can be the same or different, and
[0144] X is a C1 -C12 alkylene moiety, preferably a C1 -C8 alkylene moiety, more preferably a C1 -C6 alkylene moiety, even more preferably a C1 -C4 alkylene moiety, most preferably a C2 alkylene moiety.
[0145] In a further embodiment, a substituted aromatic carboxylic acid ester compound of general formulae (II) is preferably used as metal deactivator.
[0146] Particularly preferred metal deactivators are N,N’-bis(3(3’,5’-di-tert-butyl-4’- hydroxyphenyl)propionyl) hydrazine commercially available from BASF as Irganox MD 1024 and 2,2’-oxamidobis(ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) commercially available from Palmarole as Palmarole MDA.P.11 ; 2,2’-oxamidobis(ethyl-3-(3,5-di-tert-butyl- 4-hydroxyphenyl)propionate) commercially available from Palmarole as Palmarole MDA.P.11 is even more preferred.
[0147] As mentioned above, the metal deactivator is used in the range from 0.01 to 1.0 wt%, preferably from 0.05 to 0.8 wt%, more preferably from 0.08 to 0.6 wt%, even more preferably from 0.1 to 0.5 wt% based on the total weight of the polyolefin composition.
[0148] Additives
[0149] As mentioned above, the polyolefin composition may contain at least one additive.
[0150] Generally, the amount of these additives is in the range from 0 to 8 wt%, preferably in the range 0 to 5.0 wt%, more preferably in the range of 0.01 to 4.0 wt%, even more preferably in the range from 0.1 to 3.5 wt% based on the weight of the total polyolefin composition. It is generally to be understood that the amount of additives present in the polyolefin composition may also include the amounts of additives present in the virgin polymer in addition to the externally added additives (e.g., additives that are added during compounding). On the other hand, as not all the additives present in the recycled polymer can be quantified, the amount of such additives is not considered in the amount of additives present in the polyolefin composition.
[0151] In an embodiment, the polyolefin composition may contain one or more, preferably all of at least one of the following additives (as an additive composition): at least one sterically hindered phenol antioxidant, at least one phosphorous-based antioxidant, at least one long term heat stabilizer, and / or, at least one acid scavenger. It is to be understood that any type of combination of additives can be possible.
[0152] In a preferred embodiment, the additive composition comprises all of the following:
[0153] - a sterically hindered phenol antioxidant
[0154] - a phosphorus-based antioxidant
[0155] - a thioester antioxidant, and
[0156] - a stearate acid scavenger.
[0157] It is generally to be understood that the amount of additives present in the polyolefin composition may also include minor amounts of additives present in the virgin polymer in addition to the externally added additives.
[0158] In an embodiment, the polyolefin composition may preferably comprise at least one sterically hindered phenol antioxidant in an amount of, from 0.04 wt% to 0.55 wt%, preferably 0.05 wt% to 0.45 wt% ppm, more preferably 0.08 to 0.35 wt% based on the weight of the total composition.
[0159] The at least one sterically hindered phenol antioxidant is preferably a sterically hindered phenolic antioxidant and may preferably be selected from the group consisting of 2,6-di-tert- butyl-4-methylphenol (e.g. Ionol® CP), [octadecyl 3-(3,5-di-tert-butyl-4- hydroxyphenyl)propionate] (e.g. Irganox® 1076), benzenepropanoic acid, 3,5-bis(1 ,1 - dimethylethyl)-4-hydroxy-thiodi-2,1 -ethanediyl ester (Irganox® 1035), [pentaerythrityl- tetrakis(3-(3',5'-di-tert-butyl-4-hydroxyphenyl)propionate)] (e.g. Irganox® 1010); 1 ,3,5- trimethyl-2,4,6-tris[(3,5-di-tert-butyl-4-hydroxyphenyl)]benzene (e.g. Irganox® 1330 (FF)), 1 ,3,5-tris(3’,5’-di-tert-butyl-4’-hydroxybenzyl)-isocyanurate (e.g. Irganox® 31 14), bis-[3,3-bis- (4’-hydroxy-3’-tert.butylphenyl)butanic acid]-glycolester (e.g. Hostanox® O 3P), and 4,4’- Thiobis(2-tert-butyl-5-methylphenol) (Sumilizer WX-RC) or a combination thereof. The most preferred phenolic antioxidant is [pentaerythrityl-tetrakis(3-(3',5'-di-tert-butyl-4- hydroxyphenyl)propionate)] (e.g. Irganox® 1010).
[0160] In a further embodiment, the polyolefin composition may preferably comprise at least one phosphorous-based antioxidant in an amount of from, 0.02 to 0.40 wt%, preferably 0.04 to 0.35 wt%, more preferably 0.05 to 0.30 wt%, based on the weight of the total composition.
[0161] The at least one phosphorous-based antioxidant may preferably be selected from the group consisting of [bis(2-methyl-4,6-bis(1 ,1 -dimethylethyl)phenyl)phosphorous acid ethylester] (e.g. Irgafos 38), [tris(2,4-di-tert-butylphenyl)phosphite] (e.g. Irgafos® 168), tetrakis(2,4-di tert-butylphenyl)-4,4’-biphenylene diphosphonite (e.g. Hostanox® P-EPQ), distearyl- pentaerythrityl diphosphite (e.g. ADK-STAB PEP-8T), bis(2,4-dicumylphenyl)- pentaerythritol diphosphite (e.g. Doverphos® S-9228), and [Phosphorous acid, cyclic butylethyl propandiol, 2,4,6-tri-t-butylphenyl ester] (e.g. Ultranox® 641 ).
[0162] The most preferred phosphorus antioxidant is [tris(2,4-di-tert-butylphenyl)phosphite] (e.g. Irgafos® 168).
[0163] In still a further embodiment, the polyolefin composition comprises at least one long term heat stabilizer selected from thioester antioxidants, preferably distearyl thiodipropionate that acts as a secondary antioxidant for organic polymers. It decomposes and neutralizes hydroperoxides, formed by auto-oxidation of polymers, enhances the aging and light stability, and is also an efficient stabilizer for polyolefins. The at least one long term heat stabilizer is used in an amount of from 0.01 to 0.40 wt%, preferably 0.02 to 0.35 wt%, more preferably 0.05 to 0.30 wt%, based on the weight of the total composition.
[0164] In yet another embodiment, the mixed-plastic recyclate polyethylene composition comprises at least one acid scavenger, preferably a stearate acid scavenger, such as calcium stearate. The at least one acid scavenger is used in an amount of from, 0.01 to 0.20 wt%, preferably from 0.02 to 0.15 wt%, more preferably from 0.03 to 0.1 1 wt%, based on the weight of the total polyolefin composition.
[0165] In a further embodiment, talc may be present in the final polyolefin composition. Talc may be present in an amount from 0.1 to 1.5 wt%, preferably from 0.3 to 1.0 wt%, more preferably from 0.4 to 0.8 wt%, even more preferably from 0.5 to 0.7 wt%, based on the weight of the total polyolefin composition. In a further embodiment, alpha-nucleating agents may be present in the final polyolefin composition. Suitable alpha-nucleating agents are from the group consisting of
[0166] (i) salts of monocarboxylic acids and polycarboxylic acids, e.g. sodium benzoate or aluminum tert-butylbenzoate, and
[0167] (ii) dibenzylidenesorbitol (e.g. 1 ,3 : 2,4 dibenzylidenesorbitol) and C1 -C8-alkylsubstituted dibenzylidenesorbitol derivatives, such as methyldibenzylidenesorbitol, ethyldibenzylidenesorbitol or dimethyldibenzylidenesorbitol (e.g. 1 ,3 2,4 di(methylbenzylidene) sorbitol), or substituted nonitol-derivatives, such as 1 ,2, 3, -trideoxy 4,6:5,7-bis-O-[(4-propylphenyl) methylene]-nonitol, and
[0168] (iii) salts of diesters of phosphoric acid, e.g. sodium 2,2’-methylenebis (4,6-di-tert-buty Iphenyl) phosphate or aluminum- hydroxy-bis[2,2’-methylene-bis(4,6-di-t-butylphenyl)phosphate], and
[0169] (iv) vinylcycloalkane polymer or vinylalkane polymer, and
[0170] (v) mixtures thereof.
[0171] 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 ).
[0172] Dosing agent
[0173] In one embodiment the polyolefin composition may comprise at least one dosing agent for accepting pigments and other additives during extrusion. The at least one dosing agent may be a polypropylene homopolymer with melt flow rates MFR2 between 0.1 and 5.0 g / 10 min, preferably between 0.2 and 1.0 g / 10 min. Such a polymer is commercially available from Borealis AG. The amount of dosing agent in the polyolefin composition may be 0.5-2.5 wt%, such as 1 .0 -2.0 wt%, based on the weight of the total composition.
[0174] The
[0175] According to an embodiment the present polyolefin composition comprises a) in the range from 42 to 87 wt%, preferably from 45 to 85 wt%, more preferably from 47 to 80 wt%, even more preferably from 65 to 75 wt-%, (based on the overall weight of the polyolefin composition) of at least one heterophasic propylene copolymer (HECO) having a total ethylene (C2) content (as determined according to Crystex analysis described in method section) from 0.5 to 6.0 wt.-% (based on the total weight of the heterophasic propylene copolymer), a soluble fraction (SF) (determined according to Crystex analysis described in the method section) in the range from 2.0 to 15.0 wt% (based on the total weight of the heterophasic propylene copolymer), and a melt flow rate MFR2( measured according to ISO 1133, 2.16 kg, 230°C) in the range between 0.1 and 1 g / 10 min; b) in the range from 13 to 58 wt%, preferably from 15 to 55 wt%, more preferably from 20 to 53 wt%, even more preferably from 25 to 35 wt%, (based on the overall weight of the polyolefin composition) of a mixed-plastics polypropylene blend of recycled material (Blend A) having a polypropylene content (iPP), as determined according to IR-spectroscopy, in the range from 75.0 - 99.0 wt%(based on the total weight of the mixed-plastic polypropylene blend of recycled material), and a content of at least one of the following elements (determined by X- ray fluorescence (XRF): Fe in an amount of < 500 ppm, Ti in an amount of < 6000 ppm, Cu in an amount of < 100 ppm, Pb in an amount of < 50 ppm, Zn in amount of < 100 ppm (based on the total weight of the mixed-plastic polypropylene blend of recycled material); c) in the range from 0.01 to 1 .0 wt%, preferably from 0.05 to 0.8 wt%, more preferably from 0.08 to 0.6 wt%, even more preferably from 0.1 to 0.5 wt% of at least one metal deactivator, and d) optionally further additives (based on the overall weight of the polyolefin composition), wherein the sum of all ingredients always adds up to 100 wt%.
[0176] It is to be understood that the ratio of heterophasic copolymer and polypropylene recyclate may deviate from the above amounts and ratio due to the presence of metal deactivator, and further additives, such as antioxidants. However, the sum of all ingredients always adds up to 100%.
[0177] In one embodiment, the polyolefin composition comprises at least two heterophasic propylene copolymers, as will be described in more detail below.
[0178] In an embodiment, the polyolefin composition may have oxidation induction time (OIT) at 200°C (determined as described herein) of at least 60 min, preferably of at least 80 min, more preferably of at least 90 min, even more preferably of at least 100 min, in particular in a range from 60 to 300 min, preferably from 80 min to 250 min, more preferably in a range from 90 min to 200 min, even more preferably in a range from 100 min to 185 min. It is to be understood that the oxidation induction time (OIT) correlates with the amount and type of metal activator added.
[0179] In one embodiment, when adding a metal deactivator MD1 according to general formulae (I), the polyolefin composition may have oxidation induction time (OIT) at 200°C (determined as described herein) of at least 60 min, preferably of at least 65 min, more preferably of at least 70 min, even more preferably of at least 80 min, in particular in a range from 60 to 125 min, preferably from 65 min to 120 min, more preferably in a range from 70 min to 115 min, even more preferably in a range from 80 min to 110 min.
[0180] In another embodiment, when adding a metal deactivator MD2 according to general formulae (II), the polyolefin composition may have oxidation induction time (OIT) at 200°C (determined as described herein) of at least 80 min, preferably of at least 90 min, even more preferably of at least 100 min, in particular in a range from 80 to 300 min, preferably from 90 min to 250 min, more preferably in a range from 100 min to 200 min.
[0181] In still another embodiment, when adding a metal deactivator MD2 according to general formulae (II) in an amount from 0.1 to 0.4 (based on the overall weight of the polyolefin composition, the polyolefin composition may have oxidation induction time (OIT) at 200°C (determined as described herein) of at least 80 min, preferably of at least 90 min, even more preferably of at least 100 min, in particular in a range from 80 to 300 min, preferably from 90 min to 250 min, more preferably in a range from 100 min to 200 min.
[0182] Furthermore, the polyolefin composition may have a melt flow rate MFR2 (measured according to ISO 1 133, 2.16 kg, 230°C) of at most 3.0 g / 10 min; preferably of at most 2.5 g / 10 min, more preferably of at most 2.0 g / 10 min, even more preferably of at most 1 .5 g / 1 Omin, such as in the range from 0.1 to 3.0 g / 10 min, preferably from 0.3 to 3.0 g / 10 min, more preferably from 0.5 to 2.5 g / 1 Omin, even more preferably 0.6 to 2.0 g / 10 min, still more preferably from 0.7 to 1.5 g / 1 Omin
[0183] In a further embodiment, the polyolefin composition may have an impact strength (ISO179-1 , Charpy notched 1 eA +23°C, measured as described in the method section) of at least 3.0 kJ / m2, preferably of at least 5.0 kJ / m2, still more preferably of at least 6.0 kJ / m2, in particular in a range from 3.0 to 20 kJ / m2, more particular in a range from 5.0 to 17.0 kJ / m2, even more particular in a range from 6.0 to 15.0 kJ / m2. The polyolefin composition may further have an impact strength (ISO179-1 , Charpy notched 1 eA -20°C, measured as described in the method section) of at least 1 .0 kJ / m2, preferably of at least 1 .3 kJ / m2, still more preferably of at least 1 .5 kJ / m2, in particular in a range from 1 .0 to 15.0 kJ / m2, more particular in a range from 1.3 to 10.0 kJ / m2, even more particular in a range from 1 .5 to 5.0 kJ / m2.
[0184] In still another embodiment, the polyolefin composition has a tensile modulus at 23°C (ISO 527-2) of at least 800 MPa, preferably of at least 1000 MPa, more preferably of at least 1300 MPa, in particular in a range from 800 to 2500 MPa, more in particular in a range from 1000 to 2000 MPa, even more in particular in a range from 1300 to 1800 MPa.
[0185] In an embodiment, the polyolefin composition may have a pipe impact resistance (-10°C, 4kg, H5O, determined as described in the method section) of at least 1000 mm, preferably of at least 1500 mm, more preferably of at least 2000 mm, even more preferably of at least 2300 mm.
[0186] In an embodiment, the polyolefin composition may have a failure time in pipe internal pressures testing (at +95°C, 2.5 MPa, determined as described in the method section) of at least 1000 hours, preferably at least 1200 hours, more preferably of at least 1500 hours, even more preferably of at least 1800 hours, such as in the range from 1000 hours to 6000 hours, preferably in the range from 1200 hours to 5000 hours, more preferably in the range from 1500 hours to 4000 hours, even more preferably in the range from 1800 hours to 3000 hours.
[0187] In an embodiment, the polyolefin composition may have a time to embrittlement (oven ageing, 150 °C, determined as described in the method section) of at least 1000 hours, more preferably of at least 1100 hours, still more preferably of at least 1200 hours, still more preferably of at least 1300 hours, still more preferably of at least 1400 hours, still more preferably of at least 1500 hours, in particular in a range from 1000 to 5000 hours, even more particular in a range from 1100 to 4600 hours, even more particular in a range from 1200 to 4200 hours, even more particular in a range from 1300 to 3800 hours, even more particular in a range from 1400 to 3400 hours, even more particular in a range from 1500 to 3000 hours,
[0188] In still a further embodiment, the polyolefin composition has in the Crystex analysis one or more, preferably all of the following properties: a total ethylene (C2) content in the range from 1 .0 to 20.0 wt.-%, preferably from 1 .5 to 15.0 wt%, more preferably from 2.0 to 10.0 wt%, even more preferably from 2.5 to 8.0 wt%, and / or an intrinsic viscosity (IV) in the range from 1 .0 to 5.0 dl / g, preferably in the range 1 .5 to 4.5 dl / g, more preferably in the range from 2.0 to 4.0 dl / g; even more preferably in the range from 2.5 to 3.5 dl / g; and / or a crystalline fraction (CF) having one or more, preferably all of the following properties: an ethylene content (C2(CF)) in the range from 0.5 to 15.0 wt.-%, preferably from 0.7 to 10.0 wt%, more preferably from 0.9 to 8.0 wt%, even more preferably from 1 .0 to 4.5 wt %; and / or an intrinsic viscosity (IV(CF)) in the range from 2.0 to 5.0 dl / g, preferably in the range from 2.5 to 4.0 dl / g, more preferably in the range from 2.5 to 3.5 dl / g, and / or a soluble fraction (SF) in the range from 2.0 to 20.0 wt.-%, preferably from 3.0 to 17.0 wt%, more preferably from 4.0 to 15.0 wt%, even more preferably from 5.0 to 13.0; still more preferably from 6.0 to 10.0 wt%. the soluble fraction (SF) having one or more, preferably all of the following properties: an ethylene content (C2(SF)) in the range from 10 to 40.0 wt.-% (based on the total weight of the soluble fraction), preferably from 12.0 to 35.0 wt%, more preferably from 13.0 to 32.0 wt%, and an intrinsic viscosity (IV(SF)) in the range from 0.5 to 3.0 dl / g, preferably in the range from 0.8 to 2.5 dl / g, more preferably in the range from 1 .0 to 2.2 dl / g.
[0189] Polyolefin composition PC-1 comorisino HECO-1 and Blend A-1
[0190] In an embodiment, the present polyolefin composition PC-1 comprises: a) in the range from 45 to 85 wt%, preferably from 55 to 80 wt.-%, more preferably from 65 to 76 wt% (based on the overall weight of the polyolefin composition) of at the least one heterophasic propylene copolymer HECO-1 ; b) in the range 15 to 55 wt%, preferably from 20 to 45 wt%, still more preferably from 24 to 35 wt% (based on the overall weight of the polyolefin composition) of a mixed-plastics polypropylene blend of recycled material Blend A-1 , c) in the range from 0.08 to 0.6 wt%, even more preferably from 0.1 to 0.5 wt% of at least one metal deactivator, preferably MD1 or MD2, and d) optionally further additives (based on the overall weight of the polyolefin composition), wherein the sum of all ingredients always adds up to 100 wt%.
[0191] In one embodiment, when adding a metal deactivator MD1 according to general formulae (I), the polyolefin composition PC1 may have oxidation induction time (OIT) at 200°C (determined as described herein) of at least 60 min, preferably of at least 65 min, more preferably of at least 70 min, even more preferably of at least 80 min, in particular in a range from 60 to 125 min, preferably from 65 min to 120 min, more preferably in a range from 70 min to 115 min, even more preferably in a range from 80 min to 110 min.
[0192] In another embodiment, when adding a metal deactivator MD2 according to general formulae (II), the polyolefin composition PC1 may have oxidation induction time (OIT) at 200°C (determined as described herein) of at least 80 min, preferably of at least 90 min, even more preferably of at least 100 min, in particular in a range from 80 to 300 min, preferably from 90 min to 250 min, more preferably in a range from 100 min to 200 min.
[0193] In a further embodiment, the polyolefin composition PC1 has one or more, preferably all of the following properties:
[0194] - a melt flow rate MFR2(measured according to ISO 1133, 2.16 kg, 230°C) of at most 3.0 g / 10 min; preferably of at most 2.5 g / 10 min, more preferably of at most 2.0 g / 10 min, even more preferably of at most 1.5 g / 10min, such as in the range from 0.1 to 3.0 g / 10 min, preferably from 0.3 to 3.0 g / 10 min, more preferably from 0.5 to 2.5 g / 10min, even more preferably 0.6 to 2.0 g / 10 min, still more preferably from 0.7 to 1.5 g / 10min,
[0195] - an impact strength (ISO179-1 , Charpy notched 1 eA +23°C, measured as described in the method section) of at least 3.0 kJ / m2, preferably of at least 5.0 kJ / m2, still more preferably of at least 6.0 kJ / m2, in particular in a range from 3.0 to 20 kJ / m2, more particular in a range from 5.0 to 17.0 kJ / m2, even more particular in a range from 6.0 to 15.0 kJ / m2,
[0196] - an impact strength (ISO179-1 , Charpy notched 1 eA -20°C, measured as described in the method section) of at least 1 .0 kJ / m2, preferably of at least 1 .3 kJ / m2, still more preferably of at least 1 .5 kJ / m2, in particular in a range from 1 .0 to 15.0 kJ / m2, more particular in a range from 1.3 to 10.0 kJ / m2, even more particular in a range from 1 .5 to 5.0 kJ / m2, - a tensile modulus at 23°C (ISO 527-2) of at least 1000 MPa, preferably of at least 1300 MPa, more preferably of at least 1500 MPa in particular in a range from 1000 to 2000 MPa, even more in particular in a range from 1300 to 1800 MPa,
[0197] - a time to embrittlement (oven ageing, 150 °C, determined as described in the method section) of at least 1 100 hours, preferably of at least 1200 hours, more preferably of at least 1300 hours, even more preferably of at least 1400 hours, in particular in a range from 1 100 to 4600 hours, even more particular in a range from 1200 to 4200 hours, even more particular in a range from 1300 to 3800 hours, even more particular in a range from 1400 to 3400 hours.
[0198] In still a further embodiment, the polyolefin composition PC1 has in the Crystex analysis one or more, preferably all of the following properties:
[0199] - a total ethylene (C2) content in the range from 2.0 to 10.0 wt%, preferably from 2.5 to 8.0 wt%, more preferably from 3.0 to 6.0 wt%, and / or an intrinsic viscosity (IV) in the range 1.5 to 4.5 dl / g, preferably in the range from 2.0 to 4.0 dl / g; more preferably in the range from 2.5 to 3.5 dl / g; and / or
[0200] - a crystalline fraction (CF) having one or more, preferably all of the following properties: an ethylene content (C2(CF)) in the range from 1 .0 to 6.0 wt%, preferably from 1 .5 to 5.0 wt %; more preferably from 2.0 to 4.5 wt %; and / or an intrinsic viscosity (IV(CF)) in the range from 2.0 to 5.0 dl / g, preferably in the range from 2.5 to 4.0 dl / g, more preferably in the range from 2.5 to 3.5 dl / g, and / or
[0201] - a soluble fraction (SF) in the range from 4.0 to 15.0 wt%, preferably from 5.0 to 13.0; more preferably from 6.0 to 10.0 wt%,
[0202] - the soluble fraction (SF) having one or more, preferably all of the following properties: an ethylene content (C2(SF)) in the range from 10.0 to 30.0 wt%, preferably from 15.0 to 25.0 wt%, more preferably from 18.0 to 22.0 wt%, and an intrinsic viscosity (IV(SF)) in the range from 1.0 to 3.0 dl / g, preferably in the range from 1 .5 to 2.5 dl / g, more preferably in the range from 1 .8 to 2.2 dl / g.
[0203] Polyolefin composition PC-2 comorisino HECO-2 and Blend A-3
[0204] In an embodiment, the present polyolefin composition PC-2 comprises: a) in the range from 45 to 85 wt%, preferably from 55 to 80 wt.-%, more preferably from 65 to 76 wt% (based on the overall weight of the polyolefin composition) of at the least one heterophasic propylene copolymer HECO-2; b) in the range 15 to 55 wt%, preferably from 20 to 45 wt%, still more preferably from 24 to 35 wt% (based on the overall weight of the polyolefin composition) of a mixed-plastics polypropylene blend of recycled material Blend A-3, c) in the range from 0.08 to 0.6 wt%, preferably from 0.1 to 0.5 wt%, %, more preferably from 0.1 to 0.3 wt% of at least one metal deactivator, preferably metal deactivator MD2; and d) optionally further additives (based on the overall weight of the polyolefin composition), wherein the sum of all ingredients always adds up to 100 wt%.
[0205] In a further embodiment, the polyolefin composition PC-2 has one or more, preferably all of the following properties:
[0206] - a melt flow rate MFR2(measured according to ISO 1 133, 2.16 kg, 230°C) of at most 3.0 g / 10 min; preferably of at most 2.5 g / 10 min, more preferably of at most 2.0 g / 10 min, even more preferably of at most 1.5 g / 10min, such as in the range from 0.5 to 2.5 g / 10min, preferably 0.6 to 2.0 g / 10 min, still more preferably from 0.65 to 1.5 g / 10min,
[0207] - a time to embrittlement (oven ageing, 150 °C, determined as described in the method section) of at least 1400 hours, preferably of at least 1500 hours, more preferably of at least 1550 hours, in particular in a range from 1400 to 4600 hours, more particular in a range from 1500 to 4200 hours, even more particular in a range from 1500 to 3800 hours, still more particular in a range from 1550 to 3400 hours. PC-3 comprising HECO-1 , HECO-2 and Blend A-3
[0208] In an embodiment, the present polyolefin composition PC-3 comprises: a) in the range from 45 to 85 wt%, preferably from 55 to 80 wt.-%, more preferably from 65 to 76 wt% (based on the overall weight of the polyolefin composition) of a mixture of the at least one heterophasic propylene copolymer HECO- 1 and the least one heterophasic propylene copolymer HECO-2, b) in the range 15 to 55 wt%, preferably from 20 to 45 wt%, still more preferably from 24 to 35 wt% (based on the overall weight of the polyolefin composition) of a mixed-plastics polypropylene blend of recycled material Blend A-1 or Blend A-3, c) in the range from 0.08 to 0.6 wt%, even more preferably from 0.1 to 0.5 wt% of at least one metal deactivator, preferably metal deactivator MD2; and d) optionally further additives (based on the overall weight of the polyolefin composition), wherein the sum of all ingredients always adds up to 100 wt%.
[0209] In an embodiment, the at least one heterophasic propylene copolymer HECO-1 and the least one heterophasic propylene copolymer HECO-2 may be present in the mixture in a weight ratio of from 5:95 to 95:5, preferably from 10:90 to 90:10, more preferably from 20:80 to 80:20, even more preferably from 30:70 to 70:30, such as from 33:67 to 50:50.
[0210] For example, at least 20 wt%, preferably at least 25 wt%, more preferably at least 30 wt%, such as 33 wt% of the at least one heterophasic propylene copolymer HECO-1 and at least 20 wt%, preferably at least 25 wt%, more preferably at least 30 wt% such as at least 33 wt% of the least one heterophasic propylene copolymer HECO-2 may be present in the mixture, wherein the sum of the at least one heterophasic propylene copolymer HECO-1 and the least one heterophasic propylene copolymer HECO-2 always adds up to a sum within the above mentioned range of range of from 45 to 85 wt%, preferably from 55 to 80 wt%, more preferably from 65 to 76 wt% based on the overall weight of the polyolefin composition).
[0211] In an embodiment, when adding a metal deactivator MD2 according to general formulae (II), in an amount between 0.2 and 0.5 wt%, such as 0.4 wt%, the polyolefin composition PC-3 may have oxidation induction time (OIT) at 200°C (determined as described herein) of at least 60 min, preferably of at least 70 min, even more preferably of at least 80 min, in particular in a range from 60 to 300 min, preferably from 70 min to 250 min, more preferably in a range from 80 min to 200 min.
[0212] In a further embodiment, the polyolefin composition PC3 has one or more, preferably all of the following properties:
[0213] - a melt flow rate MFR2(measured according to ISO 1 133, 2.16 kg, 230°C) of at most 3.0 g / 10 min; preferably of at most 2.5 g / 10 min, more preferably of at most 2.0 g / 10 min, even more preferably of at most 1.5 g / 10min, such as in the range from 0.5 to 2.5 g / 10min, preferably 0.6 to 2.0 g / 10 min, still more preferably from 0.65 to 1.5 g / 10min, - a failure time in pipe internal pressures testing (DN1 10 pipes, at +95°C, 2.5 MPa, determined as described in the method section) of at least 1800 hours, preferably of at least 2000 hours, more preferably of at least 2200 hours such as in the range from 1800 hours to 6000 hours, preferably in the range from 2000 hours to 5000 hours, more preferably in the range from 2200 hours to 4000 hours .
[0214] The present invention is also directed to an article comprising the polyolefin composition according to the invention.
[0215] The polyolefin composition according to the invention can be used for a wide range of applications, in particular for pipes.
[0216] Process for preparing the
[0217] It is appreciated that the present invention also refers to a process for producing the polyolefin compositions as defined herein. The process comprises the steps of
[0218] - providing the at least one heterophasic propylene copolymer, the blend of recycled plastic material, the at least one metal deactivator and optionally further additives,
[0219] - feeding / dosing the at least one heterophasic propylene copolymer and the blend of recycled plastic material, the at least one metal deactivator and optionally further additives as a mixture into at least one extruder,
[0220] - melting the mixture in the at least one extruder, and
[0221] - optionally pelletizing the obtained polyolefin composition.
[0222] The inventive composition is preferably obtained by blending, preferably by melt mixing of the components in an extruder. The term "blending" according to this invention covers a dry mixing as well as melt mixing, like melt extruding, of substances. In case of melt mixing it is preferred to feed the substances into an extruder either as a dry blend or separately via different feeders. In case of melt mixing the obtained composition is preferably in the form of pellets. It is possible first to blend, like to melt mix, the recyclate and the heterophasic propylene copolymer (HECO) obtaining thereby a mixture, like pellets in case of melt mixing, and subsequently this mixture, e.g. said pellets, is / are blended, preferably melt mixed, with the other components of the composition, like the additives (AD). However, it is preferred to produce the composition in one step, i.e. adding all components in one mixing step. In an embodiment, the inventive composition is obtainable by melt mixing the components in a co-rotating twin screw extruder at a screw speed of preferably not more than 600 rpm, more preferably not more than 500 rpm, even more preferably not more than 400 rpm, such as in a range between 100 and 600 rpm, preferably in a range between 150 and 500 rpm, more preferably in a range between 200 and 400 rpm; and / or at a barrel temperature of not more than 270 °C, preferably not more than 260 °C, more preferably not more than 250°C, still more preferably not more than 240°C.
[0223] For instance, in case of melt mixing the components of the composition may be added via one feeder (the components may have been pre-dry mixed) or the components may be added via different feeders into the extruder obtaining thereby the composition preferably in form of pellets.
[0224] Accordingly in case the composition consists of the recyclate, the heterophasic propylene copolymer (HECO) and the optional additives (AD), both components or all three components, in case additives (AD) are present, are dry mixed or preferably melt mixed, more preferably melt extruded, obtaining thereby the composition either in form of a dry mixture or in case of melt mixing or melt extruding in form of pellets.
[0225] Alternatively first a dry mixture or pellets obtained by melt mixing of the recyclate and the heterophasic propylene copolymer (HECO) is produced and subsequently the inventive composition is obtained by mixing to said dry mixture or to said melted mixture, like the pellets, the additives (AD) in the way of dry mixing or preferably by way of melt mixing, thereby obtaining the composition either in form of a dry blend or as melted mixture, like pellets.
[0226] Experimental Section
[0227] The following Examples are included to demonstrate certain aspects and embodiments of the invention as described in the claims. It should be appreciated by those of skill in the art, however, that the following description is illustrative only and should not be taken in any way as a restriction of the invention.
[0228] Process and processing Compounding
[0229] The compounds of CE1 , CE2, IE1 to IE3 were produced on a Coperion W&P ZSK 18 corotating, twin-screw extruder (screw diameter of 18mm and L / D=40) at barrel temperatures of 180 to 230°C and screw speed of 300 rpm.
[0230] The compounds of IE4 to IE7 were produced on a Coperion W&P ZSK32 co-rotating, twin- screw extruder (screw diameter of 32mm and L / D=48) at barrel temperatures of 180 to 230°C and screw speed of 300 rpm.
[0231] Pipe extrusion
[0232] The pipe samples were produced on semi-commercial pipe extrusion lines from Krauss-Maffei GmbH. The line consists of an extruder with a 0 45 mm screw with an L / D ratio of 36D. The extruder temperature was set at 180-225°C, the melt temperature was 200-230°C and was recorded after 120 min of process stabilization. The extruder is followed by a pipe tool, which is equipped with a 0 132 mm annular die with a die gap of 2-50 mm. The line was run at a constant throughput of 120 kg / h and a line speed of about 1 .5 m / min, with water temperature of 30°C in the vacuum spray bath, vacuum level of 0.3 bars in the vacuum cooling tank. The pipe was produced with a thickness of 4 mm and outer diameter of 1 10 mm (DN110).
[0233] Test method description
[0234] Amount of “iPP”, “PVC”, “PA”, “PET”, “PS” and “C2 rich” determination by Transmission Infra-Red spectroscopy (IR)
[0235] Sample preparation:
[0236] All calibration samples and samples to be analyzed are prepared in similar way, on molten pressed plates.
[0237] Around 2 to 3 g of compounds to be analyzed are molten at 190°C. Subsequently, for 20 seconds 60 to 80 bar pressure is applied in a hydraulic heating press. Next, the samples are cooled down to room temperature in 40 second in a cold press under the same pressure, in order to control the morphology of the compound. The thickness of the plates are controlled by metallic calibrated frame plates 2,5 cm by 2,5 cm, 100 to 200 pm thick (depending MFR from the sample); two plates are produced in parallel at the same moment and in the same conditions. The thickness of each plate is measured before any FTIR measurements; all plates are between 100 to 200 pm thick.
[0238] To control the plate surface and to avoid any interference during the measurement, all plates are pressed between two double-sided silicone release papers.
[0239] In case of powder samples or heterogeneous compounds, the pressing process would be repeated three times to increase homogeneity by pressed and cutting the sample in the same conditions as described before.
[0240] Spectrometer:
[0241] Standard transmission FTIR spectroscope such as Bruker Vertex 70 FTIR spectrometer is used with the following set-up:
[0242] • a spectral range of 4000-400 cm-1,
[0243] • an aperture of 6 mm,
[0244] • a spectral resolution of 2 cm'1,
[0245] • with 16 background scans, 16 spectrum scans,
[0246] • an interferogram zero filling factor of 32
[0247] • Norton Beer strong apodisation.
[0248] Spectrum are recorded and analysed in Bruker Opus software.
[0249] Calibration samples:
[0250] As FTIR is a secondary method, several calibration standards were compounded to cover the targeted analysis range, typically from:
[0251] • 0,2 wt% to 2,5 wt% for PA
[0252] • 0,1 wt% to 5 wt% for PS
[0253] • 0,2 wt% to 2,5 wt% for PET
[0254] • 0,1 wt% to 4 wt% for PVC
[0255] The following commercial materials were used for the compounds: Borealis HC600TF as iPP, Borealis FB3450 as HDPE and for the targeted polymers such RAMAPET N1 S (Indorama Polymer) for PET, Ultramid® B36LN (BASF) for Polyamide 6, Styrolution PS 486N (Ineos) for High Impact Polystyrene (HIPS), and for PVC Inovyn PVC 263B (under powder form).
[0256] All compounds are made at small scale in a Haake kneader at a temperature below 265°C and less than 10 minutes to avoid degradation.
[0257] Additional antioxidant such as Irgafos 168 (3000 ppm) is added to minimize the degradation. Calibration:
[0258] The FTIR calibration principal is the same for all the components: the intensity of a specific FTIR band divided by the plate thickness is correlated to the amount of component determined by 1 H or 13C solution state NMR on the same plate.
[0259] Each specific FTIR absorption band is chosen due to its intensity increase with the amount of the component concentration and due to its isolation from the rest of the peaks, whatever the composition of the calibration standard and real samples.
[0260] This methodology is described in the publication from Signoret and al. “Alterations of plastic spectra in MIR and the potential impacts on identification towards recycling”, Resources, conservation and Recycling journal, 2020, volume 161 , article 104980.
[0261] The wavelength for each calibration band is:
[0262] • 3300 cm'1for PA,
[0263] • 1601 cm-1for PS,
[0264] • 1410 cm-1for PET,
[0265] • 615 cm'1for PVC,
[0266] • 1 167 cm'1for iPP.
[0267] For each polymer component i, a linear calibration (based on linearity of Beer-Lambert law) is constructed. A typical linear correlation used for such calibrations is given below: where Xi is the fraction amount of the polymer component i (in wt%)
[0268] Ei is the absorbance intensity of the specific band related to the polymer component i (in a.u. absorbance unit). These specific bands are, 3300 cm'1for PA, 1601 cm'1for PS, 1410 cm-1for PET, 615 cm'1for PVC, 1167 cm'1for iPP d is the thickness of the sample plate
[0269] A and Bi are two coefficients of correlation determined for each calibration curve No specific isolated band can be found for C2 rich fraction and as a consequence the C2 rich fraction is estimated indirectly, xC2 rich — 100 (xiPP +XPA +XPS +XPET +XEVA +XPVC +xchalk +Xtalc)
[0270] The EVA, Chalk and Talc contents are estimated “semi-quantitatively”. Hence, this renders the C2 rich content “semi-quantitative”.
[0271] The following bands are used to estimate the EVA, Chalk and Talc contents:
[0272] EVA: band centred at 607 cm-1
[0273] Chalk : band centred at 1798 cm'1
[0274] Talc : band centred at 3676 cm'1
[0275] In addition, the presence of titanium di-oxide, TiC>2 and Carbon Black are reported. Their quantifications are not feasible with FTIR.
[0276] For each calibration standard, wherever available, the amount of each component is determined by either1H or13C solution state NMR, as primary method (except for PA). The NMR measurements are performed on the exact same FTIR plates used for the construction of the FTIR calibration curves.
[0277] Crystex analysis
[0278] The crystalline (CF) and soluble fractions (SF) of the polypropylene (PP) compositions as well as the comonomer content and intrinsic viscosities of the respective fractions were analyzed by use of the Crystex (crystallisation extraction) method. Potential instruments that can be used are Crystex QC or Crystex 42 (Polymer Char; Valencia, Spain). Details of the technique and the method can be found in literature (Ljiljana Jeremie, Andreas Albrecht, Martina Sandholzer & Markus Gahleitner (2020): Rapid characterization of high-impact ethylenepropylene copolymer composition by crystallization extraction separation: comparability to standard separation methods, International Journal of Polymer Analysis and Characterization, 25:8, 581 -596)
[0279] The crystalline and amorphous fractions are separated through temperature cycles of dissolution at 160°C, crystallization at 40°C and re-dissolution in 1 ,2,4-trichlorobenzene at 160°C. Quantification of SF and CF and determination of ethylene content (C2) are achieved by means of an integrated infrared detector (IR4) and for the determination of the intrinsic viscosity (IV) an online 2-capillary viscometer is used. IR4 detector is a multiple wavelength detector measuring IR absorbance at two different bands (CH3 stretching vibration (centred at app. 2960 cm-1) and the CH stretching vibration (2700- 3000 cm-1) that are serving for the determination of the concentration and the Ethylene content in Ethylene-Propylene copolymers. IR4 detector is calibrated with series of 8 EP copolymers with known Ethylene content in the range of 2 wt.-% to 69 wt.-% (determined by 13C-NMR) and each at various concentrations, in the range of 2 and 13mg / ml. To encounter for both features, concentration and ethylene content at the same time for various polymer concentration expected during Crystex analyses the following calibration equations were applied:
[0280] Cone = a + b*Abs(CH) + c*(Abs(CH))2+ d*Abs(CH3) + e*(Abs(CH3)2+ f*Abs(CH)*Abs(CH3) (Equation 1)
[0281] CH3 / 1000TC = a + b*Abs(CH) + c* Abs(CH3) + d * (Abs(CH3) / Abs(CH)) + e * (Abs(CH3) / Abs(CH))2(Equation 2)
[0282] The constants a to f for equation 1 and a to e for equation 2 were determined by using least square regression analysis.
[0283] The CH3 / 1000TC (total C Atoms) is converted to the ethylene content in wt.-% using following relationship:
[0284] Wt.-% (Ethylene in EP Copolymers) = 100 - CH3 / 1000TC * 0.3 (Equation 3)
[0285] Amount of Soluble fraction (SF) and Crystalline Fraction (CF) are correlated through the XS calibration to the “Xylene Cold Soluble” (XCS) quantity and respectively Xylene Cold Insoluble (XCI) fractions, determined according to standard gravimetric method as per ISO16152. XS calibration is achieved by testing various EP copolymers with XS content in the range 2-31 Wt%. A linear calibration curve is used.
[0286] Wt.-% XS = a * Wt.-% SF (Equation 4)
[0287] Intrinsic viscosity (IV) of the parent EP copolymer and its soluble and crystalline fractions are determined with a use of an online 2-capillary viscometer and are correlated to corresponding IV’s determined by standard method in decalin according to ISO 1628-3. Calibration is achieved with various EP copolymers and PP polymers with IV = 2-4 dL / g. The determined calibration curve is linear.
[0288] IV (dl / g) = a * Vsp / c (Equation 5) The constant a for equation 4 and 5 was determined by using least square regression analysis respectively.
[0289] The samples to be analyzed are weighed out in concentrations of 10 mg / ml to 20mg / ml.
[0290] After automated filling of the vial with 1 ,2,4-TCB containing 250 mg / l 2,6-tert-butyl-4- methylphenol (BHT) as antioxidant, the sample is dissolved at 170°C until complete dissolution is achieved with either constant stirring or gentle shaking. To avoid sample degradation, polymer solution is blanketed with the N2 atmosphere during dissolution.
[0291] For PP composition containing inorganic fillers or pigments or any other non-TCB soluble polymeric substances removal of these is required. This can be done by hot filtration prior to injection.
[0292] A defined volume of the polymer solution is injected into the column filled with inert support where the crystallization of the sample and separation of the soluble fraction from the crystalline fraction is taking place. This process is repeated two times. During the first injection the whole sample is measured at high temperature, determining the I V[dl / g] and the C2[wt%] of the PP composition. During the second injection the soluble fraction SF (at low temperature) and the crystalline fraction CF (at high temperature) with the crystallization cycle are measured (SF[wt%], C2(SF)[wt%], IV(SF)[dl / g], C2(CF)[wt%], IV(CF)[dl / g]).
[0293] Quantification of microstructure by NMR spectroscopy (for CRYSTEX calibration) Quantitative nuclear-magnetic resonance (NMR) spectroscopy was used for calibration. Quantitative 13C{ 1 H} NMR spectra were recorded in the solution-state using a Bruker Avance Neo 400 NMR spectrometer operating at 400.15 and 100.62 MHz for 1 H and 13C respectively. All spectra were recorded using a 13C optimized 10 mm extended temperature probe head at 125°C using nitrogen gas for all pneumatics. Approximately 200 mg of material was dissolved in approximately 3 ml of 1 ,1 ,2,2-tetrachloroethane-d2 (TCE-d2) along with approximately 3 mg BHT (2,6-di-tert-butyl-4-methylphenol CAS 128-37-0) and chromium-(lll)-acetylacetonate (Cr(acac)3) resulting in a 60 mM solution of relaxation agent in solvent as described in G. Singh, A. Kothari, V. Gupta, Polymer Testing 2009, 28(5), 475.
[0294] To ensure a homogenous solution, after initial sample preparation in a heat block, the NMR tube was further heated in a rotatory oven for at least 1 hour. Upon insertion into the magnet the tube was spun at 10 Hz. This setup was chosen primarily for the high resolution and quantitatively needed for accurate ethylene content quantification. Standard single-pulse excitation was employed without NOE, using an optimised tip angle, 1 s recycle delay and a bi-level WALTZ16 decoupling scheme as described in Z. Zhou, R. Kuemmerle, X. Qiu, D. Redwine, R. Cong, A. Taha, D. Baugh, B. Winniford, J. Mag. Reson. 187 (2007) 225 and V. Busico, P. Carbonniere, R. Cipullo, C. Pellecchia, J. Severn, G. Talarico, Macromol. Rapid Common. 2007, 28, 1 128. A total of 6144 (6k) transients were acquired per spectra.
[0295] Quantitative 13C{1 H} NMR spectra were processed, integrated and relevant quantitative properties determined from the integrals. All chemical shifts were indirectly referenced to the central methylene group of the ethylene block (EEE) at 30.00 ppm using the chemical shift of the solvent. This approach allowed comparable referencing even when this structural unit was not present.
[0296] Characteristic signals corresponding to the incorporation of ethylene were observed (as described in Cheng, H. N., Macromolecules 1984, 17, 1950) and the comonomer fraction calculated as the fraction of ethylene in the polymer with respect to all monomer in the polymer: fE = ( E / ( P + E )
[0297] The comonomer fraction was quantified using the method of W-J. Wang and S. Zhu, Macromolecules 2000, 33 1157, through integration of multiple signals across the whole spectral region in the 13C{1 H} spectra. Integral regions were slightly adjusted to increase applicability across the whole range of encountered comonomer contents.
[0298] The mole percent comonomer incorporation was calculated from the mole fraction:
[0299] E [mol%] = 100 * fE
[0300] The weight percent comonomer incorporation was calculated from the mole fraction: E [wt%] = 100 * ( fE * 28.06 ) / ( (fE * 28.06) + ((1 -fE) * 42.08) ).
[0301] Frequency sweep (FS)
[0302] The characterization of polymer melts by dynamic shear measurements complies with ISO standards 6721 -1 and 6721 -10. The measurements were performed on an Anton Paar MCR501 stress controlled rotational rheometer, equipped with a 25 mm parallel plate geometry. Measurements were undertaken on compression moulded plates using nitrogen atmosphere and setting a strain within the linear viscoelastic regime. The oscillatory shear tests were done at 200°C applying a frequency range between 0.01 and 600 rad / s and setting a gap of 1.3 mm.
[0303] In a dynamic shear experiment the probe is subjected to a homogeneous deformation at a sinusoidal varying shear strain or shear stress (strain and stress controlled mode, respectively). On a controlled strain experiment, the probe is subjected to a sinusoidal strain that can be expressed by y(t) = Yo sin(wt) (1 )
[0304] If the applied strain is within the linear viscoelastic regime, the resulting sinusoidal stress response can be given by a(t) = Oo sin(wt +5) (2) where a0, and yo are the stress and strain amplitudes, respectively; co is the angular frequency; 5 is the phase shift (loss angle between applied strain and stress response); t is the time.
[0305] Dynamic test results are typically expressed by means of several different rheological functions, namely the shear storage modulus, G’, the shear loss modulus, G”, the complex shear modulus, G*, the complex shear viscosity, q*, the dynamic shear viscosity, q', the out- of-phase component of the complex shear viscosity, q" and the loss tangent, tan q, which can be expressed as follows:
[0306] The determination of so-called Shear Thinning Index, which correlates with MWD and is independent of Mw, is done as described in equation 9.
[0307] For example, the SHI(2.7 / 2io) is defined by the value of the complex viscosity, in Pa s, determined for a value of G* equal to 2.7 kPa, divided by the value of the complex viscosity, in Pa s, determined for a value of G* equal to 210 kPa.
[0308] The SHI(i / ioo) is accordingly defined by the value of the complex viscosity, in Pa s, determined for a value of G* equal to 1 kPa, divided by the value of the complex viscosity, in Pa s, determined for a value of G* equal to 100 kPa.
[0309] The values of storage modulus (G'), loss modulus (G"), complex modulus (G*) and complex viscosity (q*) were obtained as a function of frequency (co).
[0310] Thereby, e.g. q*3oorad / s (eta*3oorad / s or Eta at 300 rad / s) is used as abbreviation for the complex viscosity at the frequency of 300 rad / s and q*o.o5rad / s (eta*o.o5rad / s or Eta at 0.05 rad / s)) is used as abbreviation for the complex viscosity at the frequency of 0.05 rad / s.
[0311] The loss tangent tan (delta) is defined as the ratio of the loss modulus (G") and the storage modulus (G') at a given frequency. Thereby, e.g. tano.os is used as abbreviation for the ratio of the loss modulus (G") and the storage modulus (G') at 0.05 rad / s and tan3oo is used as abbreviation for the ratio of the loss modulus (G") and the storage modulus (G') at 300 rad / s. The elasticity balance tano.o5 / tan3oo is defined as the ratio of the loss tangent tano.os and the loss tangent tan3oo-
[0312] Besides the above mentioned rheological functions one can also determine other rheological parameters such as the so-called elasticity index El(x). The elasticity index Ei(x) is the value of the storage modulus, G’ determined for a value of the loss modulus, G” of x kPa and can be described by equation 10.
[0313] EI(x) = G' for (fi" = x kPa [Pa] (10)
[0314] For example, the EI(5kPa) is the defined by the value of the storage modulus G’, determined for a value of G” equal to 5 kPa, the EI(2kPa) is the defined by the value of the storage modulus G’, determined for a value of G” equal to 2 kPa and the EI(0.5kPa) is the defined by the value of the storage modulus G’, determined for a value of G” equal to 0.5 kPa.
[0315] The rheological polydispersity index, PI, is defined by equation 1 1 . where COCOP is the cross-over angular frequency, determined as the angular frequency for which the storage modulus, G', equals the loss modulus, G".
[0316] The values are determined by means of a single point interpolation procedure, as defined by Rheoplus software. In situations for which a given G* value is not experimentally reached, the value is determined by means of an extrapolation, using the same procedure as before. In both cases (interpolation or extrapolation), the option from Rheoplus "Interpolate y-values to x- values from parameter" and the "logarithmic interpolation type" were applied.
[0317] The so-called Zero Shear Viscosity (ZSV) is the plateau viscosity at low enough shear rate (angular frequency). It is determined by fitting the Carreau-Yasuda model on the complex viscosity versus angular frequency. The Carreau-Yasuda equation describes the viscosity curve of a material with Newtonian regions at low shear rates and a shear thinning (power law) region at medium shear rates. Fitting is done by Rheoplus or Rheocompass software by equation 12. where w angular frequency in rad / s h * complex viscosity in Pa-s h0zero shear viscosity in Pa-s a Carreau constant n shear thinning exponent
[0318] A relaxation time in s
[0319] As the ZSV (in low frequency regions) is not always fully reached within applied experimental conditions, the determination of the ZSV shall be done with special care to avoid extreme extrapolations, for example and thus, high errors.
[0320] For example, if the last experimental data point for the complex viscosity (e.g. at 0.01 rad / s) is about 70% of the calculated Zero Shear Viscosity (7i0) value by fitting of Carreau-Yasuda model, then the calculated h0can be accepted. For cases in which the deviation is higher (last experimental complex viscosity < 70% of calculated h0), the h0should not be reported. The estimation of the rheological behaviour at low frequencies, can be alternatively done, by providing the complex viscosity at an angular frequency of 0.05 rad / s (eta @0.05 rad / s).
[0321] References:
[0322]
[0001] “Rheological characterization of polyethylene fractions", Heino, E.L., Lehtinen, A., Tanner J., Seppala, J., Neste Oy, Porvoo, Finland, Theor. Appl. Rheol., Proc. Int. Congr. Rheol, 1 1th (1992), 1 , 360-362.
[0323] [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.
[0324] [3] “Definition of terms relating to the non-ultimate mechanical properties of polymers”, Pure & Appl. Chem., Vol. 70, No. 3, pp. 701 -754, 1998.
[0325] DSC
[0326] A TA Instruments Q200 Differential Scanning Calorimeter calibrated with Indium, Zinc, and Tin and operating under 50 mL / min of nitrogen flow was used. The employed thermal program consisted of a first heating step from 0 to 225°C to erase the previous thermal history and a cooling step at 10 °C / min. The melting behavior was obtained by performing a second heating scan from 0 to 225 °C at 10 °C / min. The crystallization and melting temperatures were taken as the peak values from the cooling and second heating scan respectively. The DSC trace was integrated from 50°C to the end of the melting peak to evaluate the melting enthalpy (fusion heat) or crystallization enthalpy.
[0327] OCS reflection
[0328] The cast film samples were produced and optically examined on a small-scale laboratory cast film line with installed camera detection from Optical Control Systems GmbH.
[0329] The line consists of an extruder with a 0 25 mm screw with an L / D ratio of 25. The extruder temperature was set at 200-220-230-240-240 °C in five zones, the melt temperature was 230- 240 °C. The extruder is followed by a die with a width of 150 mm and a fixed die gap of 0.5 mm. The film were produced by extrusion at a screw speed of 30 rpm with a thickness of 100 pm. During the extrusion the chill-roll temperature was set at 50-80 °C. The gels and contaminations of the film were detected and counted on 5 m2of the film during the extrusion process with reflected light and a 4096 pixel camera. During the measurement a LED light source was used. The resolution of the camera is x / y 25 pm on film. The defects, i.e., gels, contaminations and others, were divided into 4 size-classes (100-299 pm; 300-599 pm; 600- 1000 pm; >1000 pm), and the results are presented as the number of defects per square meter (1 / m2).
[0330] If the ratio between length and width of the detected spots is not more than 4.5, the spots are categorized as “gels” (having pixels with grey value of not more than 50% but more than 10% of the average grey value) or “contaminations” (having pixels with grey value of not more than 10% of the average grey value). If the ratio between length and width of the detected spots is greater than 4.5 and their pixels have grey value of not more than 50% of the average grey value, the spots are categorized as “Others”.
[0331] The “gel index” is calculated by multiplying the amount of gels in each size class by factors for the size classes (0.1 ; 1 ; 5; 10) and adding these values together.
[0332] OIT
[0333] The oxidation induction time (OIT) at 200 °C was determined with a TA Instrument Q20 according to ISO1 1357-6. Calibration of the instrument was performed with Indium and Tin, according to ISO 11357-1 . The maximum error in temperature from calibration was less than 0.1 K. Each polymer sample (cylindrical geometry with a diameter of 5 mm and thickness of 1 ±0.1 mm) with a weight of 10 ± 2 mg was placed in an open aluminium crucible, heated from 25 °C to 200 °C at a rate of 20 °C min-1in nitrogen (>99.95 vol.% N2, < 5 ppm 02) with a gas flow rate of 50 mL min-1, and allowed to rest for 5 min before the atmosphere was switched to pure oxygen (>99.95 vol.% 02), also at a flow rate of 50 mL min-1. The samples were maintained at constant temperature, and the exothermal heat associated with oxidation was recorded. The oxidation induction time was the time interval between the initiation of oxygen flow and the onset of the oxidative reaction. Each presented data point was the average of two independent measurements.
[0334] MFR2
[0335] The melt flow rate (MFR) was determined at a temperature of 230 °C and a load of 2.16 kg. according to ISO 1133 - Determination of the melt mass-flow rate (MFR) and melt volume-flow rate (MVR) of thermoplastics - Part 1 : Standard method and is indicated in g / 10 min. The MFR is an indication of the flowability, and hence the processability, of the polymer. The higher the melt flow rate, the lower the viscosity of the polymer.
[0336] Water content
[0337] The water content was determined as described in ISO15512:2019 Method A - Extraction with anhydrous methanol. There the test portion is extracted with anhydrous methanol and the extracted water is determined by a coulometric Karl Fischer Titrator.
[0338] Oven ash content 950°C
[0339] The ash content was measured at 950°C by an oven method according to ISO 3451 -1 (1997).
[0340] XRF
[0341] The instrument used for the XRF measurements was a wavelength dispersive Zetium (2,4kW) from Malvern Panalytical. The instrument was calibrated with polyolefin based standard sets from Malvern Panalytical i.e Toxel (for Cu and Pb) and custom set of calibration standards from Malvern Panalytical according to the following table for Ti and Zn range
[0342] Elements (ppm)
[0343] Ti 0 - 273
[0344] Zn 0 - 576
[0345] Elements which are not covered by standards (Fe, Co and Mo), or the content is outside of the calibrated standard range, are then analyzed with a semi-quantitative mode (software Omnian from Malvern Panalytical). For these results no LODs (Limit of detection) or LOQs (Limit of quantification) are available. If a peak is visible in the scan, it is matched, analyzed and calculated. If no peak is visible in the area of the element, it is commented as “not detected”. The CH content needed to run the semiquantitative evaluation with Omnian was estimated by the software itself.
[0346] The analysis are done under vacuum on a plaque with a diameter of 40mm and a thickness of 2mm.
[0347] Mechanical testing
[0348] Specimen preparation for mechanical testing
[0349] Test specimens for measurements of Charpy notched impact strength, tensile properties were injection moulded (IM) according to ISO 294-1 and ISO 19069-2 on the injection moulding machine Engel VC 200 / 60 tech with a screw diameter of 22 mm.
[0350] Charpy notched impact strength of injection moulded specimens
[0351] Charpy notched impact strength was determined according to ISO 179-1 / 1 eA on notched specimen of 80 mm x10 mm x 4 mm (specimen according to ISO 179-1 / 1 eA). Testing temperature was 23±2° C or -20±2° C. Injection moulding was carried out to prepare the specimens according to “specimen preparation for mechanical testing”.
[0352] Tensile testing of injection moulded specimens
[0353] The tensile properties, including tensile modulus, tensile stress at break, tensile strain at break, were determined according to ISO 527-2 method B on 1 A ISO 527-2 dogbone specimens. Following the standard, a test speed of 1 mm / min was used for tensile modulus and 50mm / min for all other properties. The testing temperature was 23±2° C. Injection moulding was carried out to prepare the specimens according to “specimen preparation for mechanical testing”.
[0354] Preparation of oven test specimens and determination of time to embrittlement
[0355] The established method for determining the ability to withstand thermo-oxidative stress or, in other words, the time to embrittlement is through oven ageing.
[0356] Oven ageing was performed on 85 x 15 x 1 mm3oven test specimens. First, plaques with a dimension of 240 x 240 x 1 mm3were compression moulded from the polymer composition according to ISO 293 and ISO 19069-2 with a Collin lab line P400S platen press using a frame tool having a thickness of 1.0 mm. Following the standard, a preheating time of 10 minutes with a preheating pressure of 0.3 MPa as contact pressure at a moulding temperature of 210 °C was applied. This was followed by a full pressure time of 5 minutes with a full pressure of 5 MPa and a cooling phase with an average cooling rate of 15 K / min until a demoulding temperature of < 40 °C was achieved.
[0357] Following the compression moulding, a set of 10 oven test specimens were obtained by diecutting 85 x 15 x 1 mm3specimens from the centre of the 240 x 240 x 1 mm3plaques. These specimens were then stored in the lab at 23 °C and 50 % relative humidity for 24 days.
[0358] Afterwards, thermal oxidation stability tests were executed in a pre-heated Voetsch VTU 60 / 60 circulating air oven in an air atmosphere at 150 °C with a set of 10 specimens. The specimens were hung vertically on oven racks using clips. The distance between the specimens was approximately 1 cm. At the same time, the timing device was started, and the time to optical embrittlement was measured. Therefore, the surface of the specimen was optically observed by the naked human eye for embrittlement once per day.
[0359] Application testing
[0360] Impact resistance evaluated by external blow test
[0361] External blow test was conducted according to ISO 1 1173: 2018.
[0362] The test pipe specimens had a wall thickness of 4 mm, outside diameter of 1 10 mm and a length of 20 mm. The testing conditions used were: striker type d90, weight of 4 kg and a testing temperature of -10 °C. Drop height for 50 % failure (H5o) was reported to evaluate the impact resistance. The maximum drop height is 3000 mm that can be measured.
[0363] Internal pressure testing (IPT)
[0364] Internal pressure test was conducted according to ISO 1167-1 :2006 standard.
[0365] The pipes were extruded with a wall thickness of 4 mm, an outer diameter of 110 mm and cut to test specimens with a length of 650 mm by a band saw. The medium was water inside and water outside environment according to ISO 1167-1 : 2006. The testing conditions used were: temperature 80°C, hoop stress 4.2 MPa; temperature 95°C, hoop stress 2.5 MPa. 3 pipe specimens were tested for each material in each condition sets. End caps of type A were used and the time of failure was determined in hours. 3 pipe specimens were tested for each material. Material / process description
[0366] Manufacturing of HECO-1
[0367] HECO-1 was prepared according toEP2145923, in the presence of a Ziegler-Natta catalyst which had been prepared as described for example in WO 00 / 68315. The matrix is made of a propylene homopolymer which was prepared in a loop reactor and a gas phase reactor (GPR1). Further information about the propylene homopolymer constituting the matrix is shown in Table 1 .Subsequently, the propylene homopolymer was transferred to a second gas phase reactor (GPR2) where the elastomeric polypropylene was prepared. Grindsted PS 432 (a glycerol ester compound) was added to the second gas phase reactor at a feed rate of 3.3 g / h. Further information about the process parameters is provided in Table 1 .
[0368] Table 1 : Polymerization conditions for HECO-1
[0369] C2 ethylene
[0370] H2 / C3 ratio, hydrogen / propylene ratio
[0371] C2 / C3 ratio ethylene / propylene ratio
[0372] Manufacturing of HECO-2
[0373] Preparation of the catalyst
[0374] First, 0.1 mol of MgCl2 x 3 EtOH was suspended under inert conditions in 250 ml of decane in a reactor at atmospheric pressure. The solution was cooled to the temperature of -15°C and 300 ml of cold TiCl4 was added while maintaining the temperature at said level. Then, the temperature of the slurry was increased slowly to 20 °C. At this temperature, 0.02 mol of diethylhexylphthalate (DOP) was added to the slurry. After the addition of the phthalate, the temperature was raised to 135 °C during 90 minutes and the slurry was allowed to stand for 60 minutes. Then, another 300 ml of TiC^ was added and the temperature was kept at 135 °C for 120 minutes. After this, the catalyst was filtered from the liquid and washed six times with 300 ml heptane at 80 °C. Then, the solid catalyst component was filtered and dried. Catalyst and its preparation concept is described in general e.g. in patent publications EP 491 566, EP 591 224 and EP 586 390.
[0375] For the preparation of the HECO as indicated below triethylaluminium (TEAL), dicyclopentyldimethoxysilane (D-donor), catalyst as produced above and vinyl cyclohexane (VCH) were added into oil, like mineral oil, e.g. Technol 68 (kinematic viscosity at 40 °C 62-74 cSt), in amounts so that TEAL / Ti was 125 mol / mol, TEAL / D donor was 5 mol / mol, and weight ratio of VCH / solid catalyst was 1 :1. The mixture was heated to 60 - 65 °C and allowed to react until the content of the unreacted vinylcyclohexane in the reaction mixture was ~ 150 ppm. Catalyst concentration in the final oil- catalyst slurry was 10 - 20 wt-%. Table 2 : Polymerization conditions for HECO-2
[0376] C2 ethylene
[0377] IV intrinsic viscosity
[0378] XCS xylene cold soluble fraction
[0379] H2 / C3 ratio hydrogen / propylene ratio
[0380] C2 / C3 ratio ethylene / propylene ratio
[0381] Loop Loop reactor
[0382] GPR 1 / 2 gas phase reactor 1 / 2
[0383] Properties of HECO-1 and HECO-2 are summarized in Table 3. Table 3: Properties of HECO-1 and HECO-2 Dosing agent
[0384] HA001 A-B1 is a commercial propylene homopolymer of Borealis having a melt flow rate MFR2 (230 °C) of 0.6 g / 10 min.
[0385] Talc (from IMI Fabi Type: HM2L) may be added during the compounding process of the final polyolefin composition or may be already present in the virgin HECO material.
[0386] Metal deactivator
[0387] The metal deactivators are listed in Table 4.
[0388] Table 4: Metal deactivators (MD)
[0389] Additives
[0390] The further additives are listed in Table 5. They may be added during the compounding process of the final polyolefin composition or may be already present in the virgin HECO material. Table 5: further additives Recyclate Blend A-1 is obtained from rigid packaging waste. Blend A-1 underwent a fine melt filtration of 100 pm. Blend A-3 is obtained from consumer waste feedstock.
[0391] The recyclate Blend A-1 and Blend A-3 used is characterized by the properties as illustrated in Table 6.
[0392] Table 6: Properties of Blend A-1 and Blend A-3 n.d.: not determinable e.g., lower than limit of detection and / or lower than limit of quantification; or “not detected” (XRF)
[0393] In Tables 7 and 8 several examples (comparative-CE; inventive-IE) are summarized. The total amounts of ingredients introduced by the virgin polymer(s), and those added during melt blending — including additives, metal deactivators, talc, and dosing agents — but not those from the recycled polymer(s), are shown in Tables 7 and 8.
[0394] Table 7 refers to a polyolefin composition comprising a) (CE1 ) heterophasic polypropylene copolymer (HECO-1 ), Blend A-1 and additives (AD1 , AD2, AD3, AD4, talc); without metal deactivator b) (IE1 ) heterophasic polypropylene copolymer (HECO-1 ), Blend A-1 and additives (AD1 , AD2, AD3, AD4, talc); and metal deactivator MD1 c) (IE2) heterophasic polypropylene copolymer (HECO-1 ), Blend A-1 and additives ( AD1 , AD2, AD3, AD4, talc); and metal deactivator MD2, d) (CE2) heterophasic polypropylene copolymer (HECO-2), Blend A-3 and additives (AD1 , AD2, AD3, AD4, talc); without metal deactivator e) (IE3) heterophasic polypropylene copolymer (HECO-2), Blend A-3 and additives ( AD1 , AD2, AD3, AD4, talc); and metal deactivator MD2, f) (IE4) heterophasic polypropylene copolymer (HECO-1 ), heterophasic polypropylene copolymer (HECO-2), Blend A-3 and additives and metal deactivator MD2, g) (IE5) heterophasic polypropylene copolymer (HECO-1 ), heterophasic polypropylene copolymer (HECO-2), Blend A-3 and additives and metal deactivator MD2, h) (IE6) heterophasic polypropylene copolymer (HECO-1 ), heterophasic polypropylene copolymer (HECO-2), Blend A-1 and additives and metal deactivator MD2, and i) (IE7) heterophasic polypropylene copolymer (HECO-1 ), heterophasic polypropylene copolymer (HECO-2), Blend A-1 and additives and metal deactivator MD2.
[0395] As can be seen in Table 7, the addition of MD1 or MD2 significantly improves the oxidation induction time (OIT) values of vPP / rPP compound (consisting of HECO-1 and fine melt filtered recyclate Blend A-1 PP. In addition, the time to embrittlement is improved for the inventive examples with metal deactivator over the comparative examples without metal deactivator. Table 7: Properties of comparative and inventive examples
[0396] As can be seen in Table 8, the addition of 0.4 wt% MD2 improves the oxidation induction time (OIT) values of polyolefin compositions consisting of HECO1 , HECO-2 and recyclate Blend A- 1 or Blend A-3 (see IE5-IE6).
[0397] Table 8: Properties of inventive examples
Claims
Claims1 . Polyolefin composition comprising a) in the range of from 40 to 90 wt%, based on the overall weight of the polyolefin composition, of at least one heterophasic propylene copolymer (HECO), said at least one heterophasic propylene copolymer having a total ethylene (C2) content, based on the overall weight of the heterophasic propylene copolymer, as determined according to Crystex analysis as described in the method section in the range from 0.5 to 6.0 wt.-%, a soluble fraction (SF), based on the overall weight of the heterophasic propylene copolymer, determined according to Crystex analysis described in the method section in the range from 2.0 to 15.0 wt%, and a melt flow rate MFR2, based on the overall weight of the heterophasic propylene copolymer, measured according to ISO 1 133, 2.16 kg, 230°C) in the range from 0.1 and 1 g / 10 min; b) in the range of from 10 to 60 wt%, based on the overall weight of the polyolefin composition, of a mixed-plastics polypropylene blend of recycled material (Blend A), said mixed-plastics polypropylene blend of recycled material having a polypropylene content (iPP), as determined according to IR- spectroscopy, in the range from 75.0 to 99.0 wt% (based on the total weight of the mixed-plastic polypropylene blend of recycled material) and a content of at least one or more, preferably all, of the following elements, based on the total weight of the mixed-plastics polypropylene blend of recycled material:Fe in an amount of < 500 ppm,Ti in an amount of < 6000 ppm,Cu in an amount of < 100 ppm,Pb in an amount of < 50 ppm, and / orZn in amount of < 100 ppm, as determined by X-ray fluorescence (XRF); c) at least one metal deactivator, andd) optionally further additives (based on the overall weight of the polyolefin composition), wherein the sum of all ingredients always adds up to 100 wt%.
2. Polyolefin composition according to claim 1 , which comprises a) in the range of from 42 to 87 wt%, preferably from 45 to 85 wt%, more preferably from 47 to 80 wt%, even more preferably from 65 to 77 wt.-%, based on the overall weight of the polyolefin composition, of the at least one heterophasic propylene copolymer (HECO) b) in the range from 13 to 58 wt%, preferably from 15 to 55 wt%, more preferably from 20 to 53 wt%, even more preferably from 23 to 35 wt%, based on the overall weight of the polyolefin composition, of the mixed-plastics polypropylene blend of recycled material (Blend A) c) in the range of from 0.01 to 1.0 wt%, preferably from 0.05 to 0.8 wt%, more preferably from 0.08 to 0.6 wt%, even more preferably from 0.1 to 0.5 wt%, of the at least one metal deactivator, and d) optionally further additives (based on the overall weight of the polyolefin composition), wherein the sum of all ingredients always adds up to 100 wt%.
3. Polyolefin composition according to any of the preceding claims, having an oxidation induction time (OIT) at 200°C (determined as described herein) of at least 60 min, preferably of at least 65 min, more preferably of at least 70 min, even more preferably of at least 80 min, in particular in a range of from 65 min to 120 min, preferably in a range of from 70 min to 115 min, more preferably in a range from 80 min to 110 min.
4. Polyolefin composition according to any of the preceding claims, having a melt flow rate MFR2(measured according to ISO 1 133, 2.16 kg, 230°C) of at most 3.0 g / 10 min; preferably of at most 2.5 g / 10 min, more preferably of at most 2.0 g / 10 min, even more preferably of at most 1.5 g / 10min, such as in the range from 0.1 to 3 g / 10 min, preferably from 0.3 to 3.0 g / 10 min, more preferably from 0.5 to 2.5 g / 1 Omin, even more preferably 0.6 to 2.0 g / 10 min, still more preferably from 0.7 to 1 .5 g / 1 Omin.
5. Polyolefin composition according to any of the preceding claims, having a time to embrittlement (oven ageing, 150 °C, determined as described in the method section) of at least 1000 hours, more preferably of at least 1100 hours, still more preferably of at least 1200 hours, still more preferably of at least 1300 hours, still more preferably of at least 1400 hours, still more preferably of at least 1500 hours.
6. Polyolefin composition according to any one of the preceding claims wherein the at least one heterophasic propylene copolymer (HECO) has a total ethylene (C2) content (as determined according to Crystex analysis as described in the method section) in the range of 0.5 to less than 5.5 wt.-%, preferably from 0.8 to 5.3 wt%, more preferably from 1 .0 to 5.2 wt%, even more preferably from 1 .0 to less than 4.5 wt.-%, preferably from 1 .0 to 4.3 wt%, more preferably from 1 .3 to 4.2 wt% (based on the total weight of the heterophasic propylene copolymer).
7. Polyolefin composition according to any one of the preceding claims, wherein the at least one heterophasic propylene copolymer (HECO) has a melt flow rate MFR2(measured according to ISO 1133, 2.16 kg, 230°C) in the range from 0.1 to 0.9 g / 10 min, preferably from 0.13 to 0.7 g / 10min, more preferably from 0.15 to 0.5 g / 10min.
8. Polyolefin composition according to any one of the preceding claims, wherein the at least one heterophasic propylene copolymer (HECO-1 ) has in the Crystex analysis one or more, preferably all of the following properties:- a total ethylene (C2) content from 0.5 to less than 4.0 wt.-%, preferably from 1 .0 to 3.5 wt%, more preferably from 1 .2 to 3.0 wt%, such as from 1 .2 to 2.5 wt% (based on the total weight of the heterophasic propylene copolymer), and / or- an intrinsic viscosity (IV) in the range from 1.0 to 6.0 dl / g, preferably in the range from 2.0 to 5.5 dl / g, more preferably in the range from 3.0 to 5.0 dl / g, and / or- a crystalline fraction (CF) having one or more, preferably all of the following properties: an ethylene content (C2(CF)) in the range from 0.3 to 3.0 wt.-% (based on the total weight of the crystalline fraction), preferably from 0.4 to 2.0 wt%, more preferably from 0.5 to 1 .5 wt%. an intrinsic viscosity (IV(CF)) in the range from 2.0 to 6.0 dl / g, preferably in the range from 2.5 to 5.5 dl / g, more preferably in the range from 3.0 to 5.0 dl / g, and / ora soluble fraction (SF) content in the range of 2.5 to 9.5 wt%, preferably in the range of 3.0 to 8.5 wt%, more preferably in the range of 3.5 to 7.5 wt% (based on the total weight of the heterophasic propylene copolymer)- the soluble fraction (SF) having one or more, preferably all of the following properties: an ethylene content (C2(SF)) in the range from 15.0 to 35.0 wt.-% (based on the total weight of the soluble fraction), preferably from 18.0 to 30.0 wt%, more preferably from 20.0 to 25.0 wt%. an intrinsic viscosity (IV(SF)) in the range from 1.0 to 6.0 dl / g, preferably in the range from 1 .5 to 5.0 dl / g, more preferably in the range from 2.0 to 4.0 dl / g.
9. Polyolefin composition according to any one of the claims 1 -7, wherein the at least one heterophasic propylene copolymer (HECO-2) has in the Crystex analysis one or more, preferably all of the following properties:- a total ethylene (C2) content from 1 .5 to less than 5.5 wt.-%, preferably from 2.0 to 5.2 wt%, more preferably from 2.5 to 5.0 wt%, such as from 3.0 to 4.8 wt% (based on the total weight of the heterophasic propylene copolymer),- an intrinsic viscosity (IV) in the range from 1.0 to 6.0 dl / g, preferably in the range from 2.0 to 5.5 dl / g, more preferably in the range from 3.0 to 5.0 dl / g, and / or- a crystalline fraction (CF) having one or more, preferably all of the following properties: an ethylene content (C2(CF)) in the range from 0.5 to 5.0 wt.-% (based on the total weight of the crystalline fraction), preferably from 1 .0 to 3.0 wt%, more preferably from 1 .2 to 2.0 wt%. an intrinsic viscosity (IV(CF)) in the range from 2.0 to 6.0 dl / g, preferably in the range from 2.5 to 5.5 dl / g, more preferably in the range from 3.0 to 5.0 dl / g, and / or- a soluble fraction (SF) content in the range of 4.0 to 14.5 wt%, preferably in the range of 5.0 to 13.0 wt%, more preferably in the range of 6.0 to 1 1.5 wt% (based on the total weight of the heterophasic propylene copolymer);- the soluble fraction (SF) having one or more, preferably all of the following properties: an ethylene content (C2(SF)) in the range from 20.0 to 40.0 wt.-% (based on the total weight of the soluble fraction), preferably from 25.0 to 35.0 wt%, more preferably from 30.0 to 33.0 wt%,an intrinsic viscosity (IV(SF)) in the range from 1.0 to 6.0 dl / g, preferably in the range from 1 .5 to 5.0 dl / g, more preferably in the range from 2.0 to 4.0 dl / g.
10. Polyolefin composition according to any of the preceding claims, wherein the mixed- plastics polypropylene blend of recycled material (Blend A) has a polypropylene content (iPP), as determined according to IR-spectroscopy as described in the method section, in the range from 80 to 98.0 wt%, more preferably from 85.0 to 97.0 wt%, even more preferably from 88.0 to 95.0 wt%, based on the total weight of the mixed-plastics polypropylene blend of recycled material.1 1 . Polyolefin composition according to any of the preceding claims wherein the mixed-plastics polypropylene blend of recycled material (Blend A) has a soluble fraction (SF) (as determined according to Crystex analysis as described in the method section) in the range from 2.0 to 20.0 wt.-%, preferably from 2.5 to 18.0 wt%, more preferably from 3.0 to 17.0 wt%, even more preferably from 3.5 to 15.0; still more preferably from 3.5 to 12.0 wt%, based on the total weight of the mixed-plastics polypropylene blend of recycled material.
12. Polyolefin composition according to any of the preceding claims, wherein the mixed- plastics polypropylene blend of recycled material (Blend A) has a melt flow rate (ISO1133, 2.16kg; 230°C) of in the range from 1 .0 to 25.0 g / 10 min, preferably from 1 .5 to 22.0 g / 1 Omin, more preferably from 2.0 to 21 .0 g / 1 Omin.
13. Polyolefin composition according to any of the preceding claims wherein the mixed- plastics polypropylene blend of recycled material (Blend A) comprises a content of one or more, preferably all, of the following elements (as determined by x-ray fluorescence XRF described in the method section), based on the total weight of the mixed-plastics polypropylene blend of recycled material:Fe in an amount of < 500 ppm, preferably < 400 ppm, more preferably < 350 ppm,Ti in an amount of < 6000 ppm, preferably < 5500 ppm, more preferably of < 5000 ppmCu in an amount of < 100 ppm, preferably < 80 ppm, more preferably < 50 ppm;Pb in an amount of < 55 ppm, preferably < 35 ppm, more preferably < 25 ppm; and / orZn in amount of < 100 ppm, preferably < 80 ppm, more preferably < 75 ppm.
14. Polyolefin composition according to one of the preceding claims, wherein the mixed- plastics polypropylene blend of recycled material (Blend A-1 ) has in the CRYSTEX analysis one or more, preferably all of the following properties:- a total ethylene (C2) content in the range from 1 .0 to 20.0 wt.-%, preferably from 2.0 to 15.0 wt%, more preferably from 5.0 to 13.0 wt%, even more preferably from 9.0 to 12.0 wt% (based on the total weight of the mixed- plastic polypropylene blend of recycled material), and / or- an intrinsic viscosity (IV) in the range from 1 .0 to 3.0 dl / g, preferably in the range from 1 .2 to 2.5 dl / g, more preferably in the range from 1 .5 to 2.0 dl / g, and / or- a crystalline fraction (CF) having one or more, preferably all of the following properties: an ethylene content (C2(CF)) in the range from 1.0 to 20.0 wt.-%, preferably from 2.0 to 15.0 wt%, more preferably from 5.0 to 13.0 wt%, even more preferably from 8.0 to 12.0 wt %; and / or an intrinsic viscosity (IV(CF)) in the range from 1 .0 to 3.0 dl / g, preferably in the range from 1.2 to 2.5 dl / g, more preferably in the range from 1.5 to 2.0 dl / g,- a soluble fraction (SF) in the range from 8.0 to 20.0 wt%, preferably in a range from 8.5 to 17.0 wt%, more preferably in a range from 9.0 to 15.0 wt%, even more preferably in a range from 10.0 to 13.0 wt%, such as from 10.0 to 12.0 wt% (based on the total weight of the mixed-plastic polypropylene blend of recycled material),- the soluble fraction (SF) having one or more, preferably all of the following properties: an ethylene content (C2(SF)) in the range from 15.0 to 40.0 wt.-% (based on the total weight of the soluble fraction), preferably from 20.0 to 35.0 wt%, more preferably from 25.0 to 32.0 wt%, an intrinsic viscosity (IV(SF)) in the range from 0.5 to 3.0 dl / g, preferably in the range from 0.8 to 2.5 dl / g, more preferably in the range from 1.0 to 2.0 dl / g.
15. Polyolefin composition according to one of the claims 1 -13, wherein the mixed-plastics polypropylene blend of recycled material (Blend A-3) has in the CRYSTEX analysis one or more, preferably all of the following properties:- a total ethylene (C2) content in the range from 1 .0 to 20.0 wt.-%, preferably from 2.0 to 15.0 wt%, more preferably from 5.0 to 13.0 wt%, even more preferably from 9.0 to 12.0 wt%, even preferably from 9.0 to 11.5 wt% (based on the total weight of the mixed-plastic polypropylene blend of recycled material), and / or- an intrinsic viscosity (IV) in the range from 1 .0 to 3.0 dl / g, preferably in the range from 1 .2 to 2.7 dl / g, more preferably in the range from 1 .5 to 2.5 dl / g; even more preferably in the range from 1 .7 to 2.2 dl / g; and / or- a crystalline fraction (CF) having one or more, preferably all of the following properties: an ethylene content (C2(CF)) in the range from 1 .0 to 20.0 wt.-%, preferably from 2.0 to 15.0 wt%, more preferably from 5.0 to 13.0 wt%, even more preferably from 6.0 to 12.0 wt %; even preferably from 9.0 to 11 .5 wt% based on the total weight of the crystalline fraction); and / or an intrinsic viscosity (IV(CF)), in the range from 1.0 to 3.0 dl / g, preferably in the range from 1 .2 to 2.7 dl / g, more preferably in the range from 1 .5 to 2.5 dl / g; even more preferably in the range from 1 .7 to 2.2 dl / g;- a soluble fraction (SF) determined according to Crystex analysis as described in the method section in the range from 2.0 to 7.0 wt%, preferably in a range from 2.5 to 6.5 wt%, more preferably in a range from 3.0 to 6.0 wt%, even more preferably in a range from 3.5 to 5.5 wt%, such as from 4.0 to 5.0 wt%.(based on the total weight of the mixed-plastic polypropylene blend of recycled material)- the soluble fraction (SF) having one or more, preferably all of the following properties, if determinable: an ethylene content (C2(SF)) in the range from 0.1 to 25.0 wt.-% (based on the total weight of the soluble fraction), preferably from 4.0 to 20.0 wt%, more preferably from 5.0 to 18.0 wt%. an intrinsic viscosity (IV(SF)) in the range from 0.2 to 3.0 dl / g, preferably in the range from 0.3 to 2.5 dl / g, more preferably in the range from 0.4 to 2.0 dl / g.
16. Polyolefin composition according to any of the preceding claims wherein the at least one metal deactivator is selected from one of the following compounds:- an alkyl hydroxyphenylalkanoyl hydrazine according to general formulae (I)wherein each of R1’, R1”, R2’ and R2” is independently a C1 -C8 alkyl moiety, preferably a C1 -C4 alkyl moiety, more preferably a C3-C4 alkyl moiety, such as a tert-C4 alkyl, wherein R1’, R1”, R2’ and R2” can be the same or different, and each of R3and R4is independently hydrogen or a C1 -C8 alkyl moiety, preferably hydrogen or a C1 -C6 alkyl moiety, such as C1 -C4 alkyl, more preferably hydrogen wherein R3and R4can be the same or different, and / or a substituted aromatic carboxylic acid ester compound, in particular any compound which is derived from an alkyl-substituted hydroxyphenyl carboxylic acid ester compound according to general formulae (II)wherein each of R1and R2is independently a C1 -C8 alkyl moiety, preferably a C1 -C4 alkyl moiety, more preferably a C3-C4 alkyl moiety, such as a tert-C4 alkyl,wherein R1and R2can be the same or different, andX is a C1 -C12 alkylene moiety, preferably a C1 -C8 alkylene moiety, more preferably a C1 -C6 alkylene moiety, even more preferably a C1 -C4 alkylene moiety, most preferably a C2 alkylene moiety.
17. Polyolefin composition according to any of the preceding claims wherein at least one additive is at least one sterically hindered phenol antioxidant, at least one phosphorous antioxidant, at least one long term heat stabilizer, preferably selected from thioester antioxidants, such as a distearyl thiodipropionate and / or, at least one acid scavenger, preferably a stearate acid scavenger, such as calcium stearate18. Polyolefin composition according to one of the preceding claims, wherein the polyolefin composition (PC-1 ) comprises a) in the range from 45 to 85 wt%, preferably from 55 to 80 wt.-%, more preferably from 65 to 76 wt% (based on the overall weight of the polyolefin composition) of at the least one heterophasic propylene copolymer HECO-1 ; b) in the range 15 to 55 wt%, preferably from 20 to 45 wt%, still more preferably from 24 to 35 wt% (based on the overall weight of the polyolefin composition) of a mixed-plastics polypropylene blend of recycled material Blend A-1 , c) in the range from 0.08 to 0.6 wt%, even more preferably from 0.1 to 0.5 wt% of at least one metal deactivator MD1 or MD2, preferably metal deactivator MD2, and d) optionally further additives (based on the overall weight of the polyolefin composition), wherein the sum of all ingredients always adds up to 100 wt%.
19. Polyolefin composition according to one of the preceding claims, wherein the polyolefin composition (PC-2) comprises a) in the range from 45 to 85 wt%, preferably from 55 to 80 wt.-%, more preferably from 65 to 76 wt% (based on the overall weight of the polyolefin composition) of at the least one heterophasic propylene copolymer HECO-2; b) in the range 15 to 55 wt%, preferably from 20 to 45 wt%, still more preferably from 24 to 35 wt% (based on the overall weight of the polyolefin composition) of a mixed-plastics polypropylene blend of recycled material Blend A-3, c) in the range from 0.08 to 0.6 wt%, even more preferably from 0.1 to 0.5 wt% of at least one metal deactivator, preferably metal deactivator MD2, andd) optionally further additives (based on the overall weight of the polyolefin composition), wherein the sum of all ingredients always adds up to 100 wt%.
20. Polyolefin composition according to one of the preceding claims, wherein the polyolefin composition (PC-3) comprises a) in the range from 45 to 85 wt%, preferably from 55 to 80 wt.-%, more preferably from 65 to 76 wt% (based on the overall weight of the polyolefin composition) of a mixture of the at least one heterophasic propylene copolymer HECO-1 and the least one heterophasic propylene copolymer HECO-2, b) in the range 15 to 55 wt%, preferably from 20 to 45 wt%, still more preferably from 24 to 35 wt% (based on the overall weight of the polyolefin composition) of a mixed-plastics polypropylene blend of recycled material Blend A-1 or Blend A-3, c) in the range from 0.08 to 0.6 wt%, even more preferably from 0.1 to 0.5 wt% of at least one metal deactivator, preferably metal deactivator MD2; and d) optionally further additives (based on the overall weight of the polyolefin composition), wherein the sum of all ingredients always adds up to 100 wt%.21 . A process for preparing the polyolefin composition according to any of the preceding claims, comprising the steps of- providing the at least one heterophasic propylene copolymer, the blend of recycled plastic material, the at least one metal deactivator and optionally further additives,- feeding / dosing the at least one heterophasic propylene copolymer and the blend of recycled plastic material, the at least one metal deactivator and optionally further additives as a mixture into at least one extruder,- melting the mixture in the at least one extruder, and- optionally pelletizing the obtained polyolefin composition.
22. Use of the polyolefin composition according to any of the claims 1 -20, for manufacturing fittings and pipes, in particular pipes.
23. An article comprising the polyolefin composition according to any of the claims 1 -20, in particular a pipe.