Polyolefin compositions obtained from recycled polyolefins

Abstract

A propylene polymer composition comprising: A) 50 to 80 wt% of a propylene homopolymer or a propylene ethylene copolymer; B) 50 to 20 wt% of a blend comprising: T1) from 20 to 40 wt% of a recycled composition comprising: (T1a) at least 70 wt% of a propylene polymer comprising from 1 to 7 wt% ethylene; (T1b) from 5 to 30 wt% of a styrene block copolymer (SBC), and optionally, (T1c) from 1 to 5 wt% by weight of an ethylene homopolymer or copolymer comprising up to 30 wt% C 3 ‑C 10 α-olefin; T2) from 60 wt% to 80 wt% of a recycled composition comprising a recycled styrene block copolymer (SBC); the sum of the amounts of T1 and T2 is 100; the sum of the amounts of A) and B) is 100.

Description

Technical Field

[0001] The present disclosure relates to soft polypropylene compositions comprising recycled elastomeric materials that can be used to prepare extruded articles. Background Art

[0002] Due to the valuable properties typical of polyolefins, such as chemical inertness, mechanical properties and non-toxicity, polyolefin compositions having elastic properties while maintaining good thermoplastic behavior have been used in many application areas. In addition, they can be advantageously converted into finished products using the same techniques used for thermoplastic polymers. In particular, flexible polymer materials are widely used in the medical field, as well as for packaging, extrusion coating, and wire and cable covering.

[0003] Elastic polypropylene compositions that retain good thermoplastic behavior have been obtained in the art by sequential copolymerization of propylene, optionally containing a small amount of olefin comonomer, and subsequently ethylene / propylene or ethylene / α-olefin copolymer mixtures. Catalysts based on halogenated titanium compounds supported on magnesium chloride are generally used for this purpose. For example, EP-A-472946 describes a flexible elasto-plastic polyolefin composition comprising, by weight: A) 10 to 50 parts of isotactic propylene homopolymer or copolymer; B) 5 to 20 parts of an ethylene copolymer that is insoluble in xylene at room temperature; and C) 40 to 80 parts of an ethylene / propylene copolymer that contains less than 40% by weight of ethylene and is soluble in xylene at room temperature; the intrinsic viscosity of the copolymer is preferably from 1.7 dl / g to 3 dl / g. The composition is relatively flexible and has good elastic properties.

[0004] Additionally, polyolefin compositions, although appreciated in terms of performance, raise concerns in terms of sustainability, particularly with reference to the fact that their production is based on the use of non-renewable resources.

[0005] Therefore, a common attempt to alleviate this problem is to at least partially replace virgin polyolefin compositions with variable amounts of recycled plastic materials.

[0006] Recycled plastic polyolefins are derived from post-consumer waste (PCW) or post-industrial waste (PIW) streams.

[0007] One of the key problems in polyolefin recycling is the difficulty in quantitatively separating the various types of polymers, so that commercially available recycled products are almost always contaminated with heterogeneous materials from various sources.

[0008] This fact results in the fact that polymer compositions comprising recycled materials are believed to suffer from lower reliability and lower performance relative to compositions made from virgin polymer alone.

[0009] It has now surprisingly been found that when a blend of recycled polymers is added to virgin polypropylene, it is possible to have an improved property profile, in particular with regard to impact and modulus values. Summary of the invention

[0010] Therefore, the object of the present disclosure is a propylene polymer composition having a melt flow rate (ISO 1133 - 1230°C / 2.16kg) value ranging from 3.0 g / 10 min to 70.0 g / 10 min, comprising:

[0011] A) 50 to 80 wt% of a propylene homopolymer or a propylene ethylene copolymer containing up to 22.0 wt% of ethylene, said propylene homopolymer or propylene ethylene copolymer having a melt flow rate (ISO 1133-1230°C / 2.16kg) ranging from 20.0 g / 10' to 100.0 g / 10';

[0012] B) 50% to 20% by weight of a blend comprising:

[0013] T1) from 20 to 40 wt. % of a recycled composition comprising:

[0014] (T1a) at least 70 wt.% of a propylene copolymer comprising from 1 wt.% to 15 wt.% of ethylene;

[0015] (T1b) from 5 to 29 wt. % of a styrene block copolymer (SBC), and optionally,

[0016] (T1c) from 1 to 15% by weight of an ethylene homopolymer or copolymer containing up to 30% by weight of C 3 -C 10 α-olefins;

[0017] The sum of the amounts of T1a, T1b, and T1c is 100;

[0018] T2) from 60 to 80 wt. % of a recycled composition comprising a recycled styrene block copolymer (SBC) having a melt flow rate (ISO 1133-1230° C. / 2.16 kg) of from 0.5 to 15.0 g / 10 min,

[0019] The sum of the amounts of T1 and T2 is 100;

[0020] The sum of the quantities of A) and B) is 100. DETAILED DESCRIPTION

[0021] The object of the present disclosure is a propylene polymer composition having a melt flow rate (ISO 1133 230°C / 2.16kg) value ranging from 3.0 g / 10min to 70.0 g / 10min; preferably from 15.0 g / 10min to 45.0 g / 10min; more preferably from 20.0 g / 10min to 35.0 g / 10min, the propylene polymer composition comprising or consisting essentially of:

[0022] A) 50 to 80 wt%; preferably 55 to 75 wt%; more preferably 58 to 72 wt%; even more preferably from 55 to 65 wt% of a propylene homopolymer or a propylene ethylene copolymer containing up to 22 wt%; preferably up to 12 wt%; more preferably up to 7 wt% of ethylene, said propylene homopolymer or propylene ethylene copolymer having a melt flow rate (ISO 1133230°C / 2.16kg) ranging from 20.0 to 100.0 g / 10min; preferably from 60.0 to 90.0 g / 10min; more preferably from 65.0 to 85.0 g / 10min;

[0023] B) 20 to 50 wt. %; preferably from 25 to 45 wt. %; more preferably from 28 to 42 wt. %; even more preferably from 35 to 45 wt. % of a blend comprising:

[0024] T1) from 20% to 40% by weight; preferably from 25% to 35% by weight; more preferably from 28% to 32% by weight of a recycled composition comprising:

[0025] (T1a) at least 70 wt.-%, preferably from 75 wt.-% to 90 wt.-% of a propylene copolymer comprising from 1 wt.-% to 15 wt.-%, preferably from 1 wt.-% to 7 wt.-% of ethylene;

[0026] (T1b) from 5 to 29 wt. %, preferably from 7 to 25 wt. %, of a styrene block copolymer (SBC), and optionally,

[0027] (T1c) from 1 to 15 wt. %, preferably from 2 to wt. %, of an ethylene homopolymer or copolymer containing up to 30 wt. % of C 3 -C 10 α-Olefins.

[0028] The sum of the amounts of T1a, T1b, and T1c is 100;

[0029] T2) from 60 to 80 wt. %; preferably from 65 to 75 wt. %; more preferably from 68 to 72 wt. % of a recycled composition comprising a recycled styrene block copolymer (SBC) having a melt flow rate (ISO 1133 230°C / 2.16 kg) of from 0.5 to 15 g / 10 min,

[0030] The sum of the amounts of T1 and T2 is 100;

[0031] The sum of the quantities of A) and B) is 100.

[0032] The term "copolymer" as used herein refers to polymers having two different repeating units in the chain and polymers having more than two different repeating units, such as terpolymers. "Ambient or room temperature" herein means a temperature of 25°C.

[0033] The term "crystalline propylene polymer" is intended in the present application to mean a propylene polymer having an amount of isotactic pentads (mmmm) higher than 70 mol %, the amount of isotactic pentads (mmmm) being determined by 13 C-MNR is measured on the fraction insoluble in xylene at 25°C; by "elastomeric" polymer is meant a polymer whose solubility in xylene at ambient temperature is higher than 50% by weight.

[0034] The term "consisting essentially of" as used herein in conjunction with a polymer or polymer composition means that in addition to the mandatory components, other components may also be present in the polymer or polymer composition, provided that the basic characteristics of the polymer or composition are not substantially affected by their presence. According to the present disclosure, examples of components that do not substantially affect the properties of a polymer or polymer composition when present in conventional amounts are catalyst residues, antistatic agents, melt stabilizers, light stabilizers, antioxidants, antacids.

[0035] The features of the components forming the polypropylene composition are not inseparably connected to each other. This means that a certain degree of preference for a certain feature does not necessarily involve the same degree of preference for the remaining features of the same or different components. On the contrary, it is intended in the present disclosure that the features of any component (A) to (B) and any preferred range of components (A) to (B) can be combined with one or more features of any preferred range of components (A) to (B) and with any possible additional components and their features described in the present disclosure.

[0036] Preferably, component A) is a virgin resin; preferably, component A is a propylene homopolymer.

[0037] The melting temperature of component A) as determined by DSC preferably ranges from 135 to 165° C. When component A) is a homopolymer, the melting temperature as determined by DSC preferably ranges from 155 to 165° C., while for copolymers it preferably ranges from 135 to 155° C.

[0038] Component A) can be prepared by polymerizing propylene, optionally in a mixture with ethylene, in the presence of a catalyst comprising the reaction product between:

[0039] i) a solid catalyst component comprising Ti, Mg, Cl and at least one internal electron donor compound;

[0040] ii) an alkylaluminum compound, and

[0041] iii) external electron donor compounds having the following general formula:

[0042] (R 7 ) a (R 8 ) b Si(OR 9 ) c , wherein a and b are integers from 0 to 2, c is an integer from 1 to 4, and the sum of (a+b+c) is 4; R 7 , R 8 and R 9 is an alkyl, cycloalkyl or aryl radical having 1 to 18 carbon atoms which may optionally contain heteroatoms.

[0043] The internal donor is preferably selected from esters of mono- or dicarboxylic organic acids, such as benzoates, malonates, phthalates and certain succinates. Examples of internal donors are described in US 4522930A, EP 045977A2 and international patent applications WO 00 / 63261 and WO 01 / 57099. Particularly suitable are phthalates and succinates. Alkyl phthalates are preferred, such as diisobutyl phthalate, dioctyl phthalate and diphenyl phthalate and benzyl butyl phthalate.

[0044] The particles of solid component (i) may have a substantially spherical morphology and an average diameter ranging between 5 μm and 150 μm, preferably from 20 μm to 100 μm, and more preferably from 30 μm to 90 μm. As particles having a substantially spherical morphology, those particles are meant in which the ratio between the larger axis and the smaller axis is equal to or lower than 1.5, and preferably lower than 1.3.

[0045] The amount of Mg may preferably range from 8 to 30%, more preferably from 10 to 25 wt%.

[0046] The amount of Ti may range from 0.5 to 7%, more preferably from 0.7 to 5 wt%.

[0047] According to one method, the solid catalyst component (i) can be prepared by reacting a titanium compound of the formula Ti(OR)q-yXy with magnesium chloride derived from an adduct of the formula MgCl2.pROH, wherein q is the valence of titanium and y is a number between 1 and q, preferably TiCl 4 , wherein p is a number between 0.1 and 6, preferably from 2 to 3.5, and R is a hydrocarbon radical having 1 to 18 carbon atoms. The adduct can be suitably prepared in spherical form by mixing an alcohol and magnesium chloride, operating under stirring conditions at the melting temperature of the adduct (100° C. to 130° C.). The adduct is then mixed with an inert hydrocarbon immiscible with the adduct, thereby producing an emulsion which is rapidly quenched, causing the adduct to solidify in the form of spherical particles. Examples of spherical adducts prepared according to this procedure are described in USP 4,399,054 and USP 4,469,648. The adduct thus obtained can be reacted directly with a Ti compound, or it can be previously subjected to a thermally controlled dealcoholation (80° C. to 130° C.) to obtain an adduct in which the number of moles of alcohol is generally less than 3, preferably between 0.1 and 2.5. The reaction with the Ti compound can be carried out by suspending the adduct (dealcoholated or as is) in a cold TiCl 4 The mixture is heated to 80°C to 130°C and maintained at this temperature for 0.5 to 2 hours. The treatment with TiCl4 can be carried out once or more. The electron donor compound can be used in the treatment with TiCl4. 4 Add during processing in desired proportions.

[0048] The alkyl-Al compound (ii) is preferably selected from trialkylaluminum compounds, such as, for example, triethylaluminum, triisobutylaluminum, tri-n-butylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum. It is also possible to use alkylaluminum halides, alkylaluminum hydrides or alkylaluminum sesquichlorides, such as AlEt 2 Cl and Al 2 Et 3 Cl 3 , possibly mixed with the above mentioned trialkylaluminium. The Al / Ti ratio is higher than 1 and may preferably be in the range between 50 and 2000.

[0049] Particularly preferred are silicon compounds (iii) wherein a is 1, b is 1, c is 2, R 7 and R 8At least one of them is selected from a branched alkyl, cycloalkyl or aryl group having 3 to 10 carbon atoms, optionally containing heteroatoms, and R9 is a C1-C10 alkyl group, in particular a methyl group. Examples of such preferred silicon compounds are methylcyclohexyldimethoxysilane (C donor), diphenyldimethoxysilane, methyl-tert-butyldimethoxysilane, dicyclopentyldimethoxysilane (D donor), diisopropyldimethoxysilane, (2-ethylpiperidinyl)tert-butyldimethoxysilane, (2-ethylpiperidinyl)tert-hexyldimethoxysilane, (3,3,3-trifluoro-n-propyl) (2-ethylpiperidinyl)dimethoxysilane, methyl (3,3,3-trifluoro-n-propyl) dimethoxysilane. In addition, it is also preferred that a is 0, c is 3, R8 is a branched alkyl or cycloalkyl group optionally containing heteroatoms and R9 is a methyl silicon compound. Examples of such preferred silicon compounds are cyclohexyltrimethoxysilane, tert-butyltrimethoxysilane and tert-hexyltrimethoxysilane.

[0050] The external electron donor compound (iii) is used in such an amount that the molar ratio between the organoaluminium compound and said external electron donor compound (iii) is from 0.1 to 200, preferably from 1 to 100 and more preferably from 3 to 50.

[0051] The polymerization process can be carried out in the gas phase, operating in one or more fluidized bed or mechanically stirred bed reactors, using an inert hydrocarbon solvent as a diluent for slurry polymerization, or using a liquid monomer (e.g. propylene) as a reaction medium for bulk polymerization. If desired, component A can be chemically treated with an organic peroxide to reduce the average molecular weight and increase the melt flow index to the value required for a specific application.

[0052] Component (T1) may be derived from post-consumer waste (PostCW) or from pre-consumer waste (Pre-CW). Preferably, it is derived from Pre-CW. Pre-consumer plastic is considered to be plastic waste diverted from the manufacturing process that is not reused, such as reprocessed, regrinded or scrapped, and is not recombined in the same process that generated it.

[0053] Component (T1a) is preferably a propylene random copolymer comprising from 1 to 6 wt%, preferably 2 to 5 wt% of ethylene. It may be derived, for example, from pre-consumer random PP material used for packaging.

[0054] Component (T1b) is preferably selected from the group consisting of SBS and SEBS rubbers, which are (partially) hydrogenated styrene-(ethylene-butadiene)-styrene block copolymers. These polymers are triblock copolymers with styrene at both ends of the polymer chain with internal polybutadiene or ethylene / butadiene, polyisoprene or hydrogenated polybutadiene or polyisoprene blocks.

[0055] SEBS copolymers are obtained via anionic polymerization and are commercially available, for example, under the trade names Kraton and Tuftec (such as, for example, Kraton SEBS G1657MS). Component (T1b) is also preferably derived from pre-consumer sources.

[0056] Preferably, component (T1c) is present in an amount ranging from 1% to 5% by weight, preferably from 2% to 4% by weight. It preferably comprises at most 30% by weight, preferably at most 20% by weight, more preferably at most 15% by weight of C 3 -C 10 Ethylene polymers of alpha-olefins. Preferably, the alpha-olefin is selected from butene-1, hexene-1 and octene-1.

[0057] The ethylene polymer is preferably selected from LDPE, LLDPE, VLDPE and polyolefin elastomers (POE) of pre-consumer origin.

[0058] The melt flow rate (ISO 1133-1230°C / 2.16kg) of the entire component (T1) may generally be in the range of from 0.5 to 30.0 g / 10min, preferably from 1.0 to 25.0 g / 10min, more preferably from 2.0 to 20.0 g / 10min.

[0059] Component (T1) according to the present disclosure preferably has a tensile modulus below 500 MPa, preferably below 400 MPa.

[0060] Component (T1) of the present disclosure preferably has a thermal conductivity of 50 to 100 kJ / m at 23°C. 2 , more preferably 55 to 80 kJ / m 2 The Charpy impact strength at -30°C preferably ranges from 5 to 20 kJ / m 2 , more preferably from 6 to 15 kJ / m 2 between.

[0061] The component (T1) of the present disclosure may exhibit an elongation at break equal to or higher than 400%, and more preferably in the range of 500% to 600%.

[0062] The melting temperature of component (T1) ranges from 140 to 160°C, preferably from 145 to 155°C.

[0063] Component (T2) is a recycled styrene block copolymer (r-SBC).

[0064] Styrene block copolymers are well known in the art. These block copolymers have a block derived from a diene, such as a polybutadiene or polyisoprene block, and a block derived from polystyrene or a derivative thereof. The block copolymers may be of different types, for example AB, ABA, A(B)4 type. The block copolymers may be hydrogenated; mixtures of two or more of the above block copolymers may be used.

[0065] Preferably, the styrene block copolymers according to the present invention have the formula AB-A', wherein A and A' are each thermoplastic end blocks comprising a styrene moiety, and wherein B is an elastomeric polybutadiene, poly(ethylene butylene) or poly(ethylene propylene) midblock. Preferably, the A and A' end blocks of the block copolymer are identical and are selected from the group consisting of polystyrene and polystyrene homologues, and even more preferably, the A and A' end blocks are polystyrene or poly(alpha-methylstyrene).

[0066] Particular preference is given to using recycled styrene-butadiene-styrene block copolymers, known as SBS.

[0067] As recycled components, recycled components of pre-consumer waste origin are preferred, which include small amounts of heterogeneous polymer and / or non-polymer components.

[0068] Preferably, the recycled styrene block copolymer comprises from 1 to 15 wt. %, more preferably from 3 to 12 wt. % of other components selected from polyethylene, polypropylene and inorganic additives. Particularly preferred are recycled styrene block copolymers comprising a propylene homopolymer, an ethylene polymer and talc as an inorganic additive.

[0069] Preferably, the (r-SBC) has a melt flow rate (ISO 1133-1230°C / 2.16kg) of from 1.0 to 10.0 g / 10 min and more preferably from 2.0 to 8.0 g / 10 min.

[0070] Furthermore, the r-SBC is preferably characterized by a density ranging from 0.95 g / cm 3 Up to 0.965g / cm 3 , more preferably 0.960 g / cm 3 Up to 0.965g / cm 3 As an additional feature, its Shore D is preferably below 45, and more preferably below 40, and in particular below 30.

[0071] If desired, the final composition comprising (a) + (b) can be chemically treated with an organic peroxide to reduce the average molecular weight and increase the melt flow index to a value required for a particular application.

[0072] Component B is a recycled styrene block copolymer (r-SBC).

[0073] Styrene block copolymers are well known in the art. These block copolymers have a block derived from a diene, such as a polybutadiene or polyisoprene block, and a block derived from polystyrene or a derivative thereof. The block copolymers may be of different types, for example AB, ABA, A(B)4 type. The block copolymers may be hydrogenated; mixtures of two or more of the above block copolymers may be used.

[0074] Preferably, the styrene block copolymers according to the present invention have the formula AB-A', wherein A and A' are each thermoplastic end blocks comprising a styrene moiety, and wherein B is an elastomeric polybutadiene, poly(ethylene butylene) or poly(ethylene propylene) midblock. Preferably, the A and A' end blocks of the block copolymer are identical and are selected from the group consisting of polystyrene and polystyrene homologues, and even more preferably, the A and A' end blocks are polystyrene or poly(alpha-methylstyrene).

[0075] Particular preference is given to using recycled styrene-butadiene-styrene block copolymers, known as SBS.

[0076] As recycled components, recycled components of pre-consumer waste origin are preferred, which include small amounts of heterogeneous polymer and / or non-polymer components.

[0077] Preferably, the recycled styrene block copolymer comprises from 1 to 15 wt. %, more preferably from 3 to 12 wt. % of other components selected from polyethylene, polypropylene and inorganic additives. Particularly preferred are recycled styrene block copolymers comprising a propylene homopolymer, an ethylene polymer and talc as an inorganic additive.

[0078] Preferably, the (r-SBC) has a melt flow rate (ISO 1133-1230°C / 2.16kg) of from 1.0 to 10.0 g / 10 min and more preferably from 2.0 to 8.0 g / 10 min.

[0079] Furthermore, the r-SBC is preferably characterized by a density ranging from 0.95 g / cm 3 Up to 0.965g / cm 3 , more preferably 0.960 g / cm 3 Up to 0.965g / cm 3 As an additional feature, its Shore D is preferably below 45, and more preferably below 40, and in particular below 30.

[0080] The overall polypropylene composition of the present disclosure preferably shows a tensile modulus value lower than that of component A).In a preferred embodiment the tensile modulus of the overall propylene polymer composition ranges from 750 MPa to 1300 MPa, more preferably from 800 MPa to 1200 MPa.

[0081] The Charpy impact value at 23°C ranges from 15.0Kj / m 2 Up to 5.0Kj / m 2 ; The Charpy impact value range at 0℃ is from 3.0Kj / m 2 Up to 7.0Kj / m 2 ; The Charpy impact value range at -20℃ is from 5.0Kj / m 2 Up to 2.0Kj / m 2 .

[0082] The overall propylene composition of the present disclosure can be obtained by mechanical blending of components (A) and (B) according to conventional techniques.

[0083] The final composition comprising components (A) and (B) can be added with conventional additives, fillers and pigments commonly used in olefin polymers, such as nucleating agents, extender oils, mineral fillers and other organic and inorganic pigments. In particular, the addition of inorganic fillers, such as talc, calcium carbonate and mineral fillers, will also improve some mechanical properties, such as flexural modulus and HDT. Talc may also have a nucleating effect.

[0084] The nucleating agent may be added to the composition of the present disclosure, for example, in an amount ranging from 0.05 wt % to 2 wt %, more preferably from 0.1 wt % to 1 wt %, relative to the total weight.

[0085] The propylene polymer composition of the present disclosure can be extruded to form films or sheets for various applications. Particularly preferred is the use of the polypropylene composition for the preparation of sheets for roofing applications.

[0086] As shown in the examples below, compositions employing component B) show a synergistic behavior with component A. In fact, by adding component B) in the amounts according to the invention, it is possible to obtain copolymers having high impact values ​​and relatively low modulus.

[0087] The following examples are given to illustrate but not to limit the present disclosure.

[0088] Examples

[0089] Characterization

[0090] Xylene soluble (XS) fraction at 25°C

[0091] 2.5g of polymer and 250ml of xylene were introduced into a glass flask equipped with a refrigerator and a magnetic stirrer. The temperature was raised to the boiling point of the solvent within 30 minutes. The resulting clear solution was then kept under reflux and stirred for 30 minutes. The closed flask was then kept in an ice water bath for 30 minutes and then in a constant temperature water bath at 25°C for 30 minutes. The resulting solid was filtered on a quick filter paper. 100ml of the filtrate was poured into a pre-weighed aluminum container, which was heated on a heating plate under a nitrogen stream to remove the solvent by evaporation. The container was then kept in an oven at 80°C under vacuum until constant weight was reached. The weight percentage of the polymer soluble in xylene at room temperature was then calculated.

[0092] The content of the xylene soluble fraction is expressed as a percentage of the original 2.5 g and then expressed as a xylene insoluble percentage (%) by difference (made up to 100%);

[0093] Melt flow rate (MFR)

[0094] As specified, measured according to ISO 1133-1 at 190°C or 230°C and a load of 2.16 kg.

[0095] Intrinsic viscosity (IV)

[0096] The sample is dissolved in tetralin at 135°C and then poured into a capillary viscometer. The viscometer tube (Ubbelohde type) is surrounded by a cylindrical glass jacket; this setup allows temperature control with a circulating thermostatic liquid. The downward passage of the meniscus is timed by a photoelectric device.

[0097] The passage of the meniscus in front of the upper lamp starts a counter with a quartz crystal oscillator. When passing the lower lamp, the meniscus stops the counter and the outflow time is recorded: this is converted into an intrinsic viscosity value by Huggins' equation (Huggins, ML, J. Am. Chem. Soc., 1942, 64, 2716), provided that the flow time of the pure solvent under the same experimental conditions (same viscometer and same temperature) is known. [η] is determined using a single polymer solution.

[0098] Polydispersity index : measured by using a parallel plate rheometer of the RMS-800 type sold by RHEOMETRICS (USA) at a temperature of 200°C, operating at an oscillation frequency increasing from 0.1 rad / sec to 100 rad / sec. From the crossover modulus, the PI can be derived by the following equation:

[0099] PI=105 / Gc

[0100] Where Gc is the crossover modulus, which is defined as the value (expressed in Pa) where G'=G", where G' is the storage modulus and G" is the loss modulus.

[0101] Ethylene (C2) content

[0102] Propylene / ethylene copolymer 13 C NMR

[0103] 13 C NMR spectra were obtained on a Bruker Av-600 spectrometer equipped with a cryoprobe, operating at 160.91 MHz in Fourier transform mode at 120 °C.

[0104] At 29.9ppm S ββ The peak of carbon (according to the nomenclature of "Monomer Sequence Distribution in Ethylene-Propylene Rubber Measured by 13C NMR. 3. Use of Reaction Probability Mode" CJ Carman, RA Harrington and CE Wilkes, Macromolecules, 1977, 10, 536) was used as an internal reference. The sample was dissolved in 1,1,2,2-tetrachloroethane-d2 at a concentration of 8 weight / volume % at 120°C. Each spectrum was acquired with 90° pulses with a 15 second delay between pulses, and CPD was used to remove 1H-13C coupling. 512 transient data were stored in 32K data points using a spectral window of 9000 Hz.

[0105] Evaluation of spectral assignments, triplet distribution and composition was performed according to Kakugo ("Carbon-13 NMR determination of monomer sequence distribution in ethylene-propylene copolymers prepared with δ-titanium trichloride-diethylaluminum chloride" M. Kakugo, Y. Naito, K. Mizunuma and T. Miyatake, Macromolecules 1982, 15, 4, 1150-1152) using the following equations:

[0106] PPP=100T ββ / S PPE=100T βδ / S EPE=100T δδ / S

[0107] PEP=100s ββ / S PEE=100S βδ / S EEE=100(0.25S γδ +0.5S δδ ) / S

[0108] S=T ββ +T βδ +T δδ +S ββ +S βδ +0.25S γδ +0.5S δδ

[0109] The mole percent ethylene content was estimated using the following equation:

[0110] E%mol=100*[PEP+PEE+EEE]. The weight percent of ethylene content was estimated using the following equation:

[0111]

[0112] Where P%mol is the molar percentage of propylene content, and MW E and MW P are the molecular weights of ethylene and propylene respectively.

[0113] According to Carman (CJ Carman, RA Harrington and CE Wilkes, Macromolecules, 1977; 10, 536), the product of the reaction ratios r 1 r 2 Calculated as:

[0114]

[0115] The stereoregularity of the propylene sequence is determined by PPP mmT ββ (28.90ppm-29.65ppm) and total T ββ The ratio of (29.80ppm-28.37ppm) was calculated as the mm content.

[0116] Samples for mechanical testing

[0117] The samples were obtained according to ISO 1873-2:2007.

[0118] Charpy Impact Test: Determined according to ISO 179-1eA and ISO 1873-2.

[0119] Elongation at Yield: Measured according to ISO 527.

[0120] Elongation at break: measured according to ISO 527.

[0121] Breaking stress: measured according to ISO 527.

[0122] Tensile Modulus: Measured according to ISO 527-2.

[0123] Tear resistance: measured on 1 mm thick extruded sheets according to method ASTM D 1004. Crosshead speed: 51 mm / min; V-die cut specimens.

[0124] Shore D: Measured according to method ISO 868 (15 seconds) on injection molded, compression molded plaques and extruded sheets.

[0125] Melting point and crystallization point

[0126] The DSC was carried out under an inert N atmosphere at a scan rate of 20 °C / min with both cooling and heating. 2 The melting point was measured on samples weighing between 5 mg and 7 mg. The instrument was calibrated using indium.

[0127] Examples

[0128] Component A)

[0129] Component A) is a commercial homopolymer sold by LyondellBasell as HA840R. The homopolymer has been visbroken with peroxide to achieve an MFR of 70.0 g / 10 min.

[0130] Component T1)

[0131] Component T1 is a recycled composition prepared separately and having an MFR of 4.3 g / 10 min, made from 80 wt% recycled random propylene ethylene copolymer comprising 4.5 wt% ethylene, 15 wt% recycled SEBS and 5 wt% recycled LLDPE.

[0132] Component T2

[0133] Component T2 is a pre-consumer recycled SBS material having an MFR of 4.1 g / 10 min and a solubility in xylene of 88 wt% at 25°C. The r-SBS also contains 3 wt% talc, 3 wt% propylene homopolymer and 4 wt% ethylene polymer. The characterization is reported in Table 1.

[0134] Table 1

[0135] T2 MFR, g / 10min 4.1 <![CDATA[Tensile modulus; (N / mm 2 )]]> 42 Shaw D (15 seconds) 20 Elongation at break % 570

[0136] Example 1 and Comparative Examples 2 and 3

[0137] The polymer granules of component A) were introduced into an extruder (Berstorff extruder), to which 1000 ppm of MS168 had been added as additive, where they were mixed with the different amounts of components T1 and T2 reported in Table 2. The polymer granules were extruded in a twin-screw extruder under a nitrogen atmosphere at a rotation speed of 250 rpm and a melt temperature of 200° C. to 250° C. The characterization of the resulting compositions is reported in Table 2.

[0138] Table 2

[0139] Example 1 Example 2 Comparative Example 3 Comparative Example 4 Component A 60 70 60 60 Component B 40 30 40 40 Component T1 (in B) 30 30 100 0 Component T2 (in B) 70 70 0 100 MFR, g / 10min 22.2 29.3 24.5 24 Tm℃ 160.6 161.3 161 162 Tc℃ 118.9 119.7 118 119 <![CDATA[Tensile modulus; (N / mm 2 )]]> 860 1060 1120 710 <![CDATA[Charpy impact at 23 °C, Kj / m 2 > 12 7.3 12 9.21 <![CDATA[Charpy impact at 0 °C, Kj / m 2 > 7.7 4.7 3 6 <![CDATA[Charpy impact -20 °C Kj / m 2 > 4.8 3.8 2 5.2 D / T TT℃ <-50 <-50 -21 <-50

[0140] The above data show that polymer compositions according to the present disclosure have an improved balance of softness and mechanical properties.

Claims

1. A propylene polymer composition having a melt flow rate value ranging from 3.0 g / 10 min to 70.0 g / 10 min as measured by ISO 1133-1 230°C / 2.16 kg, include: A) 50 to 80 wt% of a propylene homopolymer or a propylene ethylene copolymer comprising up to 22 wt% of ethylene, said propylene homopolymer or propylene ethylene copolymer having a melt flow rate in the range of from 20.0 to 100.0 g / 10 min as measured to ISO 1133-1 230°C / 2.16 kg; B) 50% to 20% by weight of a blend comprising: T1) from 20 to 40 wt. % of a recycled composition comprising: (T1a) at least 70 wt.% of a propylene copolymer comprising from 1 wt.% to 15 wt.% of ethylene; (T1b) from 5 to 29 wt% of a styrene block copolymer SBC, and optionally, (T1c) from 1 to 15 wt. % by weight of an ethylene homopolymer or copolymer containing up to 30 wt. % of C 3 -C 10 α-olefins; The sum of the amounts of T1a, T1b and T1c is 100 wt %; T2) from 60 to 80 wt.% of a recycled composition comprising a recycled styrene block copolymer SBC having a melt flow rate of from 0.5 to 15 g / 10 min, tested to ISO 1133-1230°C / 2.16 kg, The sum of the amounts of T1 and T2 is 100 wt. %; The sum of the amounts of A) and B) is 100% by weight.

2. The propylene polymer composition according to claim 1, wherein the component (A) ranges from 55 wt% to 75 wt%; and the component (B) ranges from 25 wt% to 45 wt%.

3. The propylene polymer composition of claim 1, wherein T1 ranges from 25 wt% to 35 wt%, and T2 ranges from 65 wt% to 75 wt%.

4. The propylene polymer composition according to claim 1, wherein (T1a) ranges from 75 wt % to 90 wt %; (T1b) ranges from 7 wt % to 25 wt %, and optionally, (T1c) ranges from 2 wt % to 4 wt %.

5. The propylene polymer composition of claim 1 having a melt flow rate ranging from 15.0 g / 10 min to 45.0 g / 10 min as tested by ISO 1133-1 230°C / 2.16 kg.

6. The propylene polymer composition of claim 1, wherein component (A) has a melt flow rate ranging from 60.0 g / 10 min to 90.0 g / 10 min.

7. The propylene polymer composition of claim 1, wherein component (A) is a propylene homopolymer.

8. The propylene polymer composition of claim 1, wherein component (A) ranges from 58 wt% to 72 wt%, and component B ranges from 35 wt% to 45 wt%.

9. The propylene polymer composition of claim 1, wherein T1 ranges from 28 wt% to 32 wt%, and T2 ranges from 68 wt% to 72 wt%.

10. The propylene polymer composition according to claim 1, wherein component (T2) comprises small amounts of heterogeneous polymer and / or non-polymer components.

11. The propylene polymer composition according to claim 1, wherein component (T2) comprises from 1 to 15 wt% of other components selected from polyethylene, polypropylene and inorganic materials.

12. The propylene polymer composition according to claim 1, wherein component (T1a) is a random copolymer of propylene comprising from 1 to 6 wt% of ethylene derived units.

13. The propylene polymer composition according to claim 1, wherein component (T1b) is preferably selected from the group consisting of SBS and SEBS rubbers which are hydrogenated / partially hydrogenated styrene-(ethylene-butadiene)-styrene block copolymers.

14. The propylene polymer composition according to claim 1, wherein component (T1c) is a propylene polymer comprising up to 30 wt.% of C 3 -C 10 Ethylene polymers of alpha-olefins.

15. An extruded article obtained from the propylene polymer composition according to claim 1.

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