Polyolefin composition obtained from recycled polyolefin

Abstract

A polyolefin composition comprising: A) from 35 wt% to 65 wt% of a recycled polypropylene composition; b) from 35 wt% to 65 wt% of a native polypropylene composition comprising: (b1) from 69 wt% to 92 wt% of a propylene homopolymer having: a fraction soluble in xylene at 25 DEG C of less than 3.0 wt%; and-a melt flow rate (ISO 1133, 230 DEG C / 2.16 kg) in the range of from 58 to 118 g / 10 min; (b2) from 8 wt% to 31 wt% of a copolymer of propylene and ethylene having: units derived from ethylene in an amount ranging from 27.8 wt% to 59.0 wt%, measured by 13C-NMR.

Description

Technical Field

[0001] The present disclosure relates to polypropylene compositions comprising recycled elastomeric material 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 elasticity while maintaining good thermoplastic behavior have been used in many applications. In addition, they can advantageously be converted into finished products using the same technology 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 are already known in the art by the sequential copolymerization of propylene, optionally containing small amounts of olefin comonomers, and then 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-472 946 describes a flexible elastoplastic polyolefin composition comprising, in parts by weight: A) 10 to 50 parts of an 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 preferably being between 1.7 and 3 dl / g. The composition is relatively flexible and has good elasticity.

[0004] Furthermore, 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 varying 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 been surprisingly found that when recycled polymer is added to virgin polypropylene, it is possible to have an improved property profile, in particular with regard to elongation at break. Summary of the Invention

[0010] Therefore, the object of the present disclosure is a polyolefin composition comprising:

[0011] A) 35 wt% to 65 wt% of a recycled polypropylene composition;

[0012] B) 35 wt% to 65 wt% of a virgin polypropylene composition comprising:

[0013] (b1) 69 wt% to 92 wt% of a propylene homopolymer having:

[0014] - a fraction soluble in xylene at 25° C. of less than 3.0 wt %; and

[0015] - Melt flow rate (ISO 1133, 230°C / 2.16 kg) in the range of 58 to 118 g / 10 min;

[0016] (b2) 8 to 31 wt% of a copolymer of propylene and ethylene having:

[0017] - units derived from ethylene, via 13 C-NMR measurement, its amount ranges from 27.8 wt% to 59.0 wt%;

[0018] The polypropylene composition (B) further has the following characteristics:

[0019] - Melt flow rate (ISO 1133, 230°C / 5.0kg) ranging from 26.8 to 57.2 g / 10 min;

[0020] - the amount of the fraction soluble in xylene at 25° C. ranges from 8.0 wt % to 31.0 wt %;

[0021] - the intrinsic viscosity of the fraction soluble in xylene at 25° C., measured in tetralin at 135° C., ranges from 1.2 to 3.8 dl / g and,

[0022] -Total ethylene content, as stated in the specification 13 C-NMR method, ranging from 4.5 wt% to 18.5 wt%;

[0023] In the composition, the sum of b1) and b2), referred to as the total weight of b1) and b2), is 100, and the sum of the amounts of (A) and (B), referred to as the total weight of (A) and (B), is 100;

[0024] wherein the recycled polypropylene composition (A) has

[0025] i) Propylene content above 50 wt%

[0026] iii) melt flow rate (ISO 1133, 230°C / 2.16 kg) in the range of 5.0 to 100.0 g / 10 min;

[0027] iv) Tensile modulus, measured according to ISO 527-2, in the range of 800 N / mm 2 Up to 1700N / mm 2 ;

[0028] v) Charpy impact test at 23°C, determined according to ISO 179-1eA and ISO 1873-2, range 4.0 kJ / m 2 Up to 12.0KJ / m 2 ;

[0029] vi) elongation at break, measured according to ISO 527, ranging from 30% to 90%;

[0030] vii) an FTIR spectrum of the film recorded as described in the Examples section, comprising at least two adsorption bands having at least two wavenumbers (cm -1 ):

[0031] 3303±2cm -1 ;1726±2,1642±2cm -1 ;1600±2cm -1 1550±2cm -1 ;1491±2cm -1 ;1451±2cm -1 ;1726±2cm-1;1600±2cm -1 , 748±2cm -1 ;906±2cm -1 ;839±2cm -1 , 818±2cm -1 ;748±2cm-1;695±2cm -1 . BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Shown is the FTIR spectrum of a recycled polymer grade sold by Vita plastics used as component A in the examples. DETAILED DESCRIPTION

[0033] Therefore, the object of the present disclosure is a recycled polyolefin composition comprising:

[0034] A) 35 wt% to 65 wt%; preferably 40 wt% to 60 wt%; more preferably 45 wt% to 55 wt% of a recycled polypropylene composition;

[0035] B) 35 wt% to 65 wt%; preferably 40 wt% to 60 wt%; more preferably 45 wt% to 65 wt% of a virgin polypropylene composition comprising:

[0036] -(b1) 69 wt% to 92 wt%; preferably 74 wt% to 89 wt%; more preferably 79 wt% to 87 wt% of a propylene homopolymer having:

[0037] - a fraction soluble in xylene at 25°C which is lower than 3.0 wt%; preferably higher than 0.5 wt%, and

[0038] - melt flow rate (ISO 1133 230 ° C / 5.0 kg) in the range of 58.0 to 118.0 g / 10 min; preferably in the range of 63.0 to 113.5 g / 10 min; more preferably in the range of 68.0 to 108.0 g / 10 min;

[0039] -(b2) 8 wt% to 31 wt%; preferably 11 wt% to 26 wt%; more preferably 13 wt% to 21 wt% of a copolymer of propylene and ethylene having:

[0040] - units derived from ethylene, according to 13 C-NMR measurement, its amount ranges from 27.8wt% to 59.0wt%; preferably 30.6wt% to 56.6wt%; more preferably ranges from 35.7.8wt% to 54.9wt%;

[0041] The polypropylene composition (B) further has the following characteristics:

[0042] - melt flow rate (ISO 1133 230 ° C / 5.0 kg) in the range of 26.8 to 57.2 g / 10 min; preferably 29.4 to 54.6 g / 10 min; more preferably in the range of 31.8 to 52.2 g / 10 min;

[0043] - the amount of the fraction soluble in xylene at 25° C. ranges from 8.0 wt % to 31.0 wt %, preferably from 10.0 wt % to 26.0 wt %; more preferably from 12.0 wt % to 24.0 wt %;

[0044] - the intrinsic viscosity of the fraction soluble in xylene at 25° C., measured in tetralin at 135° C., ranges from 1.2 to 3.8 dl / g; preferably from 1.5 to 3.4 dl / g; more preferably ranges from 1.8 to 3.0 dl / g; and,

[0045] - According to the instructions 13 The total ethylene content measured by C-NMR method is in the range of 4.5 wt% to 18.5 wt%; preferably 5.5 wt% to 15.8 wt%; more preferably in the range of 6.5 wt% to 13.7 wt%;

[0046] In the composition, the sum of b1) and b2), referred to as the total weight of b1) and b2), is 100, and the sum of the amounts of (A) and (B), referred to as the total weight of (A) and (B), is 100;

[0047] The recycled polypropylene composition (A) has:

[0048] use 13 Propylene content measured by C-NMR, higher than 50 wt%, preferably higher than 55 wt%; more preferably in the range of 60 wt% to 95 wt%;

[0049] Melt flow rate (ISO 1133 230°C / 2.16kg) ranges from 5.0 to 100.0 g / 10 min; preferably ranges from 15.0 to 90.0 g / 10 min; more preferably ranges from 20.0 to 70.0 g / 10 min

[0050] Tensile modulus, measured according to ISO 527-2, range 800N / mm 2 Up to 1700N / mm 2 ; The preferred range is 1000N / mm 2 Up to 1500N / mm 2 More preferably, the tensile modulus, measured according to ISO 527-2, is in the range of 1200 N / mm 2 Up to 1400N / mm 2 ;

[0051] Charpy impact test at 23°C, determined according to ISO 179-1eA and ISO 1873-2, range 4.0 kJ / m 2 Up to 12.0KJ / m 2 ; The preferred range is 4.8KJ / m 2 Up to 10.0KJ / m 2 ; More preferably, the range is 5.5KJ / m 2 Up to 7.3KJ / m 2 .

[0052] Elongation at break, measured according to ISO 527, ranges from 30% to 90%; preferably ranges from 35% to 80%; more preferably ranges from 38% to 71%

[0053] The FTIR spectrum of the film recorded as described in the Examples section comprises at least two adsorption bands having at least two wave numbers (cm -1 ):

[0054] 3303±2cm -1 ;1726±2,1642±2cm -1 ;1600±2cm -1 1550±2cm -1 ;1491±2cm -1 ;1451±2cm -1 ;1726±2cm -1 ;1600±2cm -1 , 748±2cm -1 ;906±2cm -1 ;839±2cm -1 , 818±2cm -1 ;748±2cm -1 ;695±2cm -1 .

[0055] As used herein, the term "copolymer" refers to a polymer having two different repeating units.

[0056] The term "recycled" is used to refer to polymeric material derived from at least one cycle of processing into an article, as opposed to virgin polymer, which is polymer that has not undergone at least one cycle of processing into an article.

[0057] As used herein in conjunction with a polymer or polymer composition, the term "consisting essentially of" 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 materially affected by their presence. Examples of components that do not materially affect the properties of a polymer or polymer composition when present in conventional amounts according to the present disclosure are catalyst residues, antistatic agents, melt stabilizers, light stabilizers, antioxidants, antacids.

[0058] The features of the components forming the polypropylene composition are not excessively linked to each other. This means that a certain preference for one feature does not necessarily relate to the same preference for the remaining features of the same or different components. On the contrary, it is intended in the present disclosure that any component (A) to (B) and any preferred range of a feature of component (A) to (B) can be combined with any preferred range of one or more features of component (A) to (B) and with any possible additional components and their features described in this disclosure.

[0059] Component B) can be prepared by polymerizing propylene, optionally in a mixture with ethylene, in the presence of a catalyst comprising the reaction product between:

[0060] i) a solid catalyst component comprising Ti, Mg, Cl and at least one internal electron donor compound;

[0061] ii) an alkylaluminum compound and,

[0062] iii) external electron donor compounds having the following general formula:

[0063] (R 7 ) a (R 8 ) bS i(OR 9 ) c , wherein a and b are integers from 0 to 2, c is an integer from 1 to 4 and the sum (a+b+c) is 4; and R 7 、R 8 and R 9 is an alkyl, cycloalkyl or aryl group having 1 to 18 carbon atoms, which may contain heteroatoms.

[0064] 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 Pat. No. 4,522,930A, EP 045,977A2 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, as well as benzylbutyl phthalate.

[0065] The particles of the solid component have a substantially spherical morphology and an average diameter ranging from 5 to 150 μm, preferably from 20 to 100 μm and more preferably from 30 to 90 μm. As particles having a substantially spherical morphology, it is meant that the ratio between the major axis and the minor axis is equal to or lower than 1.5, and preferably lower than 1.3.

[0066] The amount of Mg may preferably range from 8 to 30%, more preferably from 10 to 25 wt%.

[0067] The amount of Ti may range from 0.5 to 7 wt%, more preferably from 0.7 to 5 wt%.

[0068] According to one method, the solid catalyst component (i) can be prepared by reacting a titanium compound of the formula Ti(OR)q-yXy, wherein q is the valence of titanium and y is a number between 1 and q, preferably TiCl4, with a magnesium chloride derived from an adduct of the formula MgCl2·pROH, 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 (100-130°C). The adduct is then mixed with an inert hydrocarbon immiscible with the adduct, thereby producing an emulsion, which is rapidly quenched, resulting in the solidification of the adduct 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 the Ti compound, or it can be previously subjected to a thermally controlled dealcoholation (80-130°C) to obtain an adduct in which the number of moles of alcohol is less than 3, preferably 0.1-2.5. The reaction with the Ti compound can be carried out by suspending the adduct (dealcoholated or as such) in cold TiCl4; heating the mixture to 80-130°C and maintaining it at this temperature for 0.5-2 hours. The treatment with TiCl4 can be carried out one or more times. The electron donor compound can be added during the treatment with TiCl4 in the desired ratio.

[0069] The alkyl-Al compound (ii) is preferably selected from trialkylaluminum compounds, such as triethylaluminum, triisobutylaluminum, tri-n-butylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum. Alkylaluminum halides, alkylaluminum hydrides or alkylaluminum sesquichlorides, such as AlEt2Cl and Al2Et3Cl3, may also be used, which may be mixed with the above-mentioned trialkylaluminums. The Al / Ti ratio is higher than 1 and may preferably be in the range of 50 to 2000.

[0070] Particularly preferred are silicon compounds (iii) in which a is 1, b is 1, c is 2, at least one of R7 and R8 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. Furthermore, preferred are silicon compounds wherein a is 0, c is 3, R8 is a branched alkyl or cycloalkyl group optionally containing heteroatoms, and R9 is methyl. Examples of such preferred silicon compounds are cyclohexyltrimethoxysilane, tert-butyltrimethoxysilane, and tert-hexyltrimethoxysilane.

[0071] The external electron donor compound (iii) is used in such an amount that the molar ratio of the organoaluminium compound to said external electron donor compound (iii) is 0.1-200, preferably 1-100, more preferably 3-50.

[0072] Component B) can be prepared in a continuous sequential polymerization process, wherein component b1) is prepared in the first reactor and component (b2) is prepared in the second and third reactors in the presence of component (b1) according to known techniques and in the gas phase, or in the liquid phase in the presence or absence of an inert diluent, or by mixed liquid-gas techniques.

[0073] Preferably, components (b1), (b2) are prepared in a gas phase reactor.

[0074] Component B) is preferably a commercial polymer grade, for example Moplen EP448S sold by Lyondellbasell.

[0075] Component (A) can be a post-industrial resin (PIR) or a post-consumer resin (PCR).

[0076] Post-industrial resins (PIRs) are waste products generated by manufacturing processes that are recycled or used again in the same material.

[0077] Post-consumer resin (PCR) is defined as recyclate derived from an end product that has completed its life cycle as a consumer item and would otherwise be disposed of as waste.

[0078] 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 the value required for a specific application.

[0079] The overall polypropylene composition of the present disclosure preferably exhibits higher tensile modulus values ​​than component B). In a preferred embodiment, the tensile modulus of the overall propylene polymer composition ranges from 740 MPa to 2000 MPa, more preferably from 940 to 1850 MPa; even more preferably from 1090 to 1690 MPa.

[0080] The preferred range of Charpy impact value at 23°C is 4.3KJ / m 2 Up to 18.5KJ / m 2 More preferably, its range is 5.5KJ / m 2 Up to 15.1KJ / m 2 Even more preferably, it is in the range of 6.5KJ / m 2 Up to 10.1KJ / m 2 .

[0081] The elongation at break of the composition of the invention can be improved relative to the elongation at break of component A). In particular, within the scope of the claimed protection, the elongation at break is surprisingly higher relative to compositions containing less component A).

[0082] Preferably, the elongation at break ranges from 25% to 80%; more preferably from 30% to 75%, even more preferably from 35% to 70%.

[0083] The overall propylene composition of the present disclosure can be obtained by mechanically blending components (A) and (B) according to conventional techniques.

[0084] 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 also brings about improvements in some mechanical properties such as flexural modulus and HDT. Talc can also have a nucleating effect.

[0085] For example, the nucleating agent may be added to the composition of the present disclosure 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.

[0086] The propylene polymer compositions of the present disclosure can be used to produce injection molded articles, especially injection molded articles in the automotive field.

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

[0088] Example

[0089] Characterization

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

[0091] 2.5 g of polymer and 250 ml 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 over 30 minutes. The resulting clear solution was then held at reflux and stirred for an additional 30 minutes. The sealed flask was then placed in an ice-water bath for 30 minutes, followed by a 25°C constant-temperature water bath for 30 minutes. The resulting solid was filtered through rapid filter paper. 100 ml of the filtrate was poured into a pre-weighed aluminum container, which was heated on a hot 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 a constant weight was achieved. The weight percentage of polymer soluble in xylene at room temperature was then calculated.

[0092] The xylene soluble fraction is expressed as a percentage of the original 2.5 g and the xylene insoluble fraction is expressed as a percentage (%) by difference (complementary to 100%).

[0093] Melt flow rate (MFR)

[0094] Measured according to ISO 1133-1 at 230°C with a load of 2.16 kg or 5 kg, as specified.

[0095] Intrinsic viscosity (IV)

[0096] The sample is dissolved in tetralin at 135°C and poured into a capillary viscometer. The viscometer tube (Ubbelohde type) is surrounded by a cylindrical glass sleeve; this setup allows temperature control using 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. The meniscus stops the counter when it passes the lower lamp, and the discharge time is recorded: if the flow time of the pure solvent is known under the same experimental conditions (same viscometer and same temperature), it can be converted into an intrinsic viscosity value using the Huggins equation (Huggins, ML, J. Am. Chem. Soc., 1942, 64, 2716). A single polymer solution is used to determine [η].

[0098] Polydispersity Index: Determined 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 obtained by the following equation:

[0099] PI=105 / Gc

[0100] Wherein Gc is the crossover modulus, which is defined as the value (expressed in Pa) when 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 carbon peak (according to the nomenclature of "Monomer sequence distribution in ethylene-propylene rubber measured by 13C NMR. 3. Use of reaction probability models" 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 8 wt / v% concentration at 120°C. Each spectrum was acquired using a 90° pulse with a 15 second delay between pulse and CPD to remove 1H-13C coupling. 512 transients 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 equation:

[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 percentage of ethylene content was estimated using the following equation:

[0110] E%mol=100*[PEP+PEE+EEE]

[0111] The weight percent ethylene content was estimated using the following equation:

[0112]

[0113] 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.

[0114] According to Carman (CJ Carman, RA Harrington and CE Wilkes, Macromolecules 1977; 10, 536), the product of the reaction ratios r1r2 is calculated as:

[0115]

[0116] The stereoregularity of the propylene sequence is determined by PPP mmT ββ (28.90-29.65ppm) and the entire T ββ The ratio of (29.80-28.37 ppm) was calculated as the mm content.

[0117] FTIR spectroscopy

[0118] By infrared (IR) spectroscopy, the IR spectra were measured by recording the samples against a background level of air using a Fourier transform infrared (FTIR) spectrometer. The data acquisition parameters of the instrument were:

[0119] ■Purge time: at least 30 seconds

[0120] ■Collection time: at least 3 minutes

[0121] ■Apodization method: Happ-Genzel

[0122] Resolution: 2cm -1 .

[0123] Sample Preparation - Using a hydraulic press, a thick sheet was obtained by compression molding about 1 g of sample between two sheets of aluminum foil. A small portion of the obtained sheet was cut to form a film. The film thickness was set at ~720 cm -1 The maximum absorbance of the CH2 absorption band with 1.3 au is at about 180 ± 10 ° C (356 ° F) and about 10 kg / cm 2 The pressure was then released and the sample was removed from the press and allowed to cool to room temperature. The spectra of the pressed films were recorded as absorbance versus wave number (cm -1 ) function.

[0124] Samples for mechanical testing

[0125] The samples were obtained according to ISO 1873-2:2007.

[0126] Charpy impact test is determined according to ISO 179-1eA and ISO 1873-2

[0127] Elongation at yield: measured according to ISO 527.

[0128] Elongation at break: measured according to ISO 527

[0129] Breaking stress: measured according to ISO 527.

[0130] Tensile modulus according to ISO 527-2

[0131] Melting point and crystallization point

[0132] Melting points are measured using a DSC instrument according to ISO 11357-3, at a scan rate of 20° C. / min in cooling and heating, on samples weighing between 5 and 7 mg, under an inert N 2 flow. Indium is used for instrument calibration.

[0133] Example

[0134] Example 1

[0135] Component A)

[0136] Component A is a recycled polymer grade sold by Vita plastics with an MFR of 51 g / 10 min. The properties of the polymer are reported in Table 1.

[0137] Table 1

[0138] Component A MFR, 2.16kg g / 10min 51 <![CDATA[Tensile modulus; (N / mm 2 )]]> 1330 <![CDATA[Charpy impact at 23 °C KJ / m 2 > 6.9 Elongation at break % 43 Propylene C3 content wt% >60

[0139] Component B)

[0140] Component B is commercial grade Moplen E448S, which can be synthesized according to procedures known in the art. Moplen EP448S has the properties listed in Table 2.

[0141] Table 2

[0142] Component b1) XS wt% <3.0 MFR 230℃ / 2.16kg g / 10min 83 Separation wt% 84 Component b2) C2 content wt% 46 Separation wt% 16 Overall composition MFR 230℃ / 5kg g / 10min 51.0 XS wt% 16 IV on XS dl / g 2.3 C2 content wt% 7.5

[0143] The fraction of XS that is soluble in xylene at 25°C

[0144] C2 ethylene-derived units

[0145] IV intrinsic viscosity

[0146] 50 wt% of component A) was blended with 50 wt% of component B) in an extruder (Berstorff extruder) with the addition of 1000 ppm of MS168 and 3000 ppm of DHT-4A, based on the total weight of A+B. The polymer pellets were extruded in a twin-screw extruder under a nitrogen atmosphere at a rotation speed of 250 rpm and a melt temperature of 200-250°C. The characteristics of the resulting composition are reported in Table 3.

[0147] Table 3

[0148] A B Example 1 Comparative Example 2 Comparative Example 3 Component A 100 50 30 70 Component B 100 50 70 30 MFR, 2.16kg g / 10min 51.0 47.0 53.0 47.0 48.0 <![CDATA[Tensile modulus; (N / mm 2 )]]> 1330 1250 1410 1430 1460 <![CDATA[Charpy impact test at 23 °C in KJ / m 2 > 6.9 6.8 7.5 6.6 7.3 Elongation at break % 43 42 49 40.4 35.6

[0149] The polymer compositions according to the present disclosure have an improved balance of mechanical properties relative to component A alone. In particular, the elongation at break is increased relative to comparative examples 2 and 3 and relative to components A and B alone.

Claims

1. A polyolefin composition comprising: A) 35 wt% to 65 wt% of a recycled polypropylene composition; B) 35 wt% to 65 wt% of a virgin polypropylene composition comprising: (b1) 69 wt% to 92 wt% of a propylene homopolymer having: - a fraction soluble in xylene at 25° C. of less than 3.0 wt %; and - Melt flow rate (ISO 1133, 230°C / 2.16 kg) in the range of 58 to 118 g / 10 min; (b2) 8 to 31 wt% of a copolymer of propylene and ethylene having: - units derived from ethylene, via 13 C-NMR measurement, its amount ranges from 27.8 wt% to 59.0 wt%; The polypropylene composition (B) further has the following characteristics: - Melt flow rate (ISO 1133, 230°C / 5.0kg) ranging from 26.8 to 57.2 g / 10 min; - the amount of the fraction soluble in xylene at 25° C. ranges from 8.0 wt % to 31.0 wt %; - the intrinsic viscosity of the fraction soluble in xylene at 25° C., measured in tetralin at 135° C., ranges from 1.2 to 3.8 dl / g and, -Total ethylene content, as stated in the specification 13 C-NMR method, ranging from 4.5 wt% to 18.5 wt%; In the composition, the sum of b1) and b2), referred to as the total weight of b1) and b2), is 100, and the sum of the amounts of (A) and (B), referred to as the total weight of (A) and (B), is 100; wherein the recycled polypropylene composition (A) has i) Propylene content above 50 wt% iii) melt flow rate (ISO 1133, 230°C / 2.16 kg) in the range of 5.0 to 100.0 g / 10 min; iv) Tensile modulus, measured according to ISO 527-2, in the range of 800 N / mm 2 Up to 1700N / mm 2 ; v) Charpy impact test at 23°C, determined according to ISO 179-1eA and ISO 1873-2, range 4.0 kJ / m 2 Up to 12.0KJ / m 2 ; vi) elongation at break, measured according to ISO 527, ranging from 30% to 90%; vii) an FTIR spectrum of the film recorded as described in the Examples section, comprising at least two adsorption bands having at least two wavenumbers (cm -1 ): 3303±2cm -1 ;1726±2,1642±2cm -1 ;1600±2cm -1 1550±2cm -1 ;1491±2cm -1 ;1451±2cm -1 ;1726±2cm -1 ;1600±2cm -1 ,748±2cm -1 ;906±2cm -1 ;839±2cm -1 ,818±2cm -1 ;748±2cm -1 ;695±2cm -1 。 2. The propylene polymer composition of claim 1, wherein component (A) ranges from 40 wt% to 60 wt%; and component (B) ranges from 40 wt% to 60 wt%.

3. The propylene polymer composition according to claim 1 or 2, wherein in component B), component b1) ranges from 74 wt% to 89 wt%; and component b2) ranges from 11 wt% to 26 wt%.

4. The propylene polymer composition of claim 1, wherein component b1) has a melt flow rate (ISO 1133 230°C / 5.0 kg) of 63.0 to 113.5 g / 10 min.

5. The propylene polymer composition according to claim 1, wherein in component b2), 13 The amount of units derived from ethylene measured by C-NMR ranged from 30.6 wt% to 56.6 wt%.

6. The propylene polymer composition of claim 1, wherein component B) has a melt flow rate (ISO 1133 230°C / 5.0 kg) of 29.4 to 54.6 g / 10 min.

7. The propylene polymer composition according to claim 1, wherein component (B) has an amount of a xylene-soluble fraction at 25°C of 10.0 wt% to 26.0 wt%.

8. The propylene polymer composition of claim 1, wherein component (B) has an intrinsic viscosity of the xylene soluble fraction at 25°C, measured in tetralin at 135°C, in the range of 1.5 to 3.4 dl / g.

9. The propylene polymer composition according to claim 1, wherein in component (B), 13 The total ethylene content measured by the C-NMR method ranged from 5.5 wt% to 15.8 wt%.

10. The propylene polymer composition according to any of the preceding claims, wherein in component A), the melt flow rate (ISO 1133-1 230°C / 2.16 kg) of the total component (A) is in the range of 15.0 to 90.0 g / 10 min.

11. The propylene polymer composition according to claim 1, wherein in component (A), 13 The total propylene content measured by C-NMR method was higher than 55 wt%.

12. The propylene polymer composition according to claim 1, wherein in component (A), the tensile modulus measured according to ISO 527-2 is in the range of 1000 N / mm 2 Up to 1500N / mm 2 .

13. The propylene polymer composition according to claim 1, wherein in component (A), the Charpy impact test at 23°C, determined according to ISO 179-1eA and ISO 1873-2, is in the range of 4.8 kJ / m 2 Up to 10.0KJ / m 2 .

14. The propylene polymer composition of claim 1, wherein in component A) the elongation at break measured according to ISO 527 is in the range of 35 to 80%.

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

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