Soft and flexible polyolefin composition

Abstract

There is disclosed a polyolefin composition comprising: (A) a copolymer of propylene and 1 - hexene in an amount of 10 - 40% by weight, the copolymer comprising 1.0 - 6.0% by weight of units derived from 1 - hexene based on the weight of (A) and having a melt flow rate (MFR A ) measured according to ISO 1133 at 230 °C and 2.16 kg in the range of 20 to 60 g / 10 min; and (B) a copolymer of propylene and at least one α - olefin of the formula CH2=CHR and optionally a diene in an amount of 60 - 90% by weight, where R is H or a linear or branched C2 - C8 alkyl, and where the copolymer comprises 20 - 35% by weight of the α - olefin based on the total weight of (B), wherein the polyolefin composition comprises an amount of xylene - soluble fraction (XS(tot)) equal to or higher than 65% by weight at 25 °C, and the amounts of (A), (B) and XS(tot) are based on the total weight of (A)+(B). The polyolefin composition can be used for roof applications and the production of geomembranes.

Description

Technical Field

[0001] The present invention relates to a thermoplastic polyolefin composition which can be used to prepare sheets or films having high resistance to perforation and deformation while maintaining flexibility and good mechanical properties. The sheets or films are particularly suitable for roofing applications. Background Art

[0002] Elastomers and thermoplastic polyolefins are mainly used in the art for the production of sheets and films for single-ply roofing.

[0003] Traditionally, polyvinyl chloride (PVC) and other chlorinated TPOs have been used to prepare thermoplastic roofing sheets that can be heat-welded. However, PVC requires plasticizers to have the flexibility required for roofing applications. Aging by plasticizer loss and the presence of chlorine in the polymer chains are the driving factors for replacing PVC with chlorine-free thermoplastic polyolefins having the required mechanical properties in the absence of plasticizers.

[0004] Multi-phase polyolefin compositions are used to prepare sheets or films for roofing applications, and the compositions are heat-weldable, flexible, and easy to recycle.

[0005] WO03 / 076509 discloses a polyolefin composition for roofing applications having good toughness, the composition comprising: (A) 15 - 40 wt% of a crystalline copolymer of propylene and (B) 60 - 85 wt% of an elastomeric fraction comprising a copolymer of propylene and ethylene and a copolymer of ethylene and an α-olefin.

[0006] WO2009 / 077481 discloses a film comprising a base layer (A) and a top layer (B). The base layer (A) is made of a multi-phase composition comprising: (A) 10 - 40 wt.% of a propylene homopolymer or copolymer; and (b) 60 - 90 wt.% of one or more copolymers of ethylene and a C3 - C10 α-olefin. The top layer (B) comprises a propylene polymer selected from a propylene homopolymer, a copolymer of propylene and ethylene or a C4 - C10 α-olefin, and combinations thereof. The film has good tensile properties and good tear resistance.

[0007] A highly inert multi-layer film having good tear resistance and puncture resistance is disclosed in WO2012 / 072426. The film comprises: a base layer (A) and a top layer (B) - the base layer (A) comprises: (A) 10 - 40 wt.% of a propylene homopolymer or copolymer and (b) 60 - 90 wt.% of one or more copolymers of ethylene and a C3 - C10 α-olefin. The top layer (B) comprises an ethylene homopolymer or copolymer having a density of 0.915 to 0.980 g / cm 3 3.

[0008] Soft and flexible polyolefin compositions for roofing and for the production of geomembranes are known from WO2009 / 080485, which discloses a composition comprising: (A) 10-40 wt% of a propylene / hexene-1 copolymer containing 2.5-10 wt% of hexene-1 and having a melt flow rate of 0.5-100 g / 10 min, and (B) 60-85 wt% of an ethylene copolymer containing 40 wt% or less of ethylene and having a solubility in xylene of higher than 70 wt%.

[0009] There is still a need in the art for polyolefin compositions having a suitable balance of physical-mechanical properties and good processability, which are particularly suitable for the preparation of sheets or films that remain flexible and have good puncture and tear resistance. Summary of the Invention

[0010] The present invention provides a polyolefin composition comprising:

[0011] (A) 10-40% by weight of a copolymer of propylene and hexene-1, said copolymer comprising 1.0-6.0% by weight of units derived from hexene-1 based on the weight of (A) and having a melt flow rate (MFR A ) measured according to ISO 1133, at 230 °C and 2.16 kg in the range of 20 to 60 g / 10 min; and

[0012] (B) 60-90% by weight of a copolymer of propylene and at least one α-olefin of the formula CH2=CHR and optionally a diene, where R is H or a linear or branched C2-C8 alkyl group, and where said copolymer comprises 20-35% by weight of α-olefin based on the total weight of (B),

[0013] wherein the polyolefin composition comprises an amount of fraction soluble in xylene at 25 °C (XS(tot)) equal to or higher than 65% by weight, the amounts of (A), (B) and XS(tot) being based on the total weight of (A)+(B).

[0014] The present invention also provides a sheet or film comprising the polyolefin composition, said polyolefin composition comprising:

[0015] (A) 10-40% by weight of a copolymer of propylene and hexene-1, said copolymer comprising 1.0-6.0% by weight of units derived from hexene-1 based on the weight of (A) and having a melt flow rate (MFRA) measured according to ISO 1133, at 230 °C and 2.16 kg in the range of 20 to 60 g / 10 min; and

[0016] (B) A copolymer of 60 - 90% by weight of propylene with at least one α-olefin of the formula CH2=CHR and optionally a diene, where R is H or a linear or branched C2 - C8 alkyl, and where the copolymer contains 20 - 35% by weight of the α-olefin based on the total weight of (B).

[0017] Wherein the polyolefin composition contains an amount of at least 65% by weight of the fraction soluble in xylene at 25 °C (XS(tot)), and the amounts of (A), (B), and XS(tot) are based on the total weight of (A)+(B).

[0018] The polyolefin composition of the present invention exhibits good balance of mechanical properties, especially flexibility and softness, while maintaining good elastic properties and having significant puncture resistance and tear resistance.

[0019] The polyolefin composition has reduced tackiness and is thus easy to process into sheets or films, especially suitable for roofing applications and sheets or films for the production of geomembranes.

[0020] Sheets or films containing the polyolefin composition of the present invention are soft and flexible and easy to install.

[0021] Although multiple embodiments are disclosed, other embodiments will become apparent to those skilled in the art from the following detailed description. As will be apparent, certain embodiments as disclosed herein can be modified in various obvious aspects, all of which modifications do not depart from the spirit and scope of the claims as presented herein. Accordingly, the following detailed description should be regarded as illustrative in nature and not restrictive. Detailed Description

[0022] In one embodiment, the propylene copolymer (A) contains 2.0 - 5.0% by weight, preferably 2.8 - 4.8% by weight, more preferably 3.0 - 4.0% by weight of 1-hexene, and the amount of 1-hexene is based on the weight of component (A).

[0023] In one embodiment, based on the weight of component (A), the propylene copolymer (A) further contains 0.1 - 3.0% by weight of at least one other α-olefin selected from the group consisting of: ethylene, 1-butene, 4-methyl-1-pentene, 1-octene, and combinations thereof.

[0024] In some embodiments, the propylene copolymer (A) has a melt flow rate (MFR A) of 25 to 55 g / 10 min, preferably 30 to 50 g / 10 min, measured according to ISO 1133 at 230 °C and 2.16 kg.

[0025] In some embodiments, the propylene copolymer (A) comprises, based on the weight of component (A), less than 12.0% by weight, preferably less than 9.0% by weight, of the fraction soluble in xylene at 25 °C (XS A ), more preferably XS A is present in an amount in the range of 5.0 - 12.0% by weight, preferably 6.0 - 9.0% by weight, more preferably 6.0 - 8.0% by weight.

[0026] In some embodiments, the propylene copolymer (B) comprises, based on the total weight of component (B), more than 80% by weight, preferably more than 85% by weight, more preferably more than 90% by weight, of the fraction soluble in xylene at 25 °C (XS B ).

[0027] In one embodiment, the upper limit of the amount of the fraction of component (B) soluble in xylene at 25 °C (XS B ) is 97% by weight based on the total weight of component (B) for each lower limit.

[0028] In some embodiments, component (B) comprises a first copolymer (B1) and a second copolymer (B2) of propylene with at least one α-olefin of the formula CH2=CHR and optionally a diene, where R is H or a linear or branched C2-C8 alkyl, provided that the total amount of α-olefin contained in the propylene copolymer (B) is 20 - 35% by weight based on the total weight of component (B).

[0029] In one embodiment, component (B) comprises:

[0030] (B1) 30 - 60% by weight, preferably 40 - 55% by weight, of a first copolymer of propylene with at least one α-olefin of the formula CH2=CHR and optionally a diene, where R is H or a linear or branched C2-C8 alkyl, and where the first propylene copolymer comprises 20 - 40% by weight, preferably 25 - 35% by weight, of α-olefin and more than 80% by weight, preferably more than 85% by weight, more preferably more than 90% by weight, of the fraction soluble in xylene at 25 °C (XS B1 ), the amounts of α-olefin and XS B1 being based on the weight of component (B1); and

[0031] (B2) A second copolymer of 40-70% by weight, preferably 45-60% by weight, of propylene with at least one α-olefin of the formula CH2=CHR and optionally a diene, where R is H or a straight-chain or branched C2-C8 alkyl group, and where the second propylene copolymer contains 25-45% by weight, preferably 30-43% by weight, of α-olefin and a fraction (XS B2 ) that is soluble in xylene at 25°C of more than 80% by weight, preferably more than 85% by weight, more preferably more than 90% by weight, the amounts of α-olefin and XS B2 being based on the weight of component (B2); and

[0032] where the amounts of (B1) and (B2) are based on the total weight of component (B).

[0033] In one embodiment, the upper limit of the amount of the fraction (XS B1 and / or XS B2 ) of component (B1) and / or component (B2) that is soluble in xylene at 25°C is 97% by weight for each lower limit, the amounts of XS B1 and XS B2 being based on the weights of components (B1) and (B2), respectively.

[0034] In one embodiment, the upper limit of XS B1 and XS B2 is 97% by weight for each lower limit, the amounts of XS B1 and XS B2 being based on the weights of components (B1) and (B2), respectively.

[0035] In some embodiments, at least one α-olefin contained in component (B), (B1), and (B2) is independently selected from the group consisting of ethylene, butene-1, hexene-1, 4-methyl-pentene-1, octene-1, and combinations thereof. In a preferred embodiment, the α-olefin is ethylene.

[0036] Optionally, the propylene copolymers (B), (B1), and / or (B2) contain repeating units derived from a diene, and the diene is preferably independently selected from the group consisting of butadiene, 1,4-hexadiene, 1,5-hexadiene, ethylidene-1-norbornene, and combinations thereof.

[0037] In some embodiments, based on the weight of the relevant component, the total amount of the repeating units derived from a diene contained in the propylene copolymers (B), (B1), and / or (B2) is 1 to 10% by weight.

[0038] In some embodiments of the present invention, the polyolefin composition comprises a fraction (XS(tot)) soluble in xylene at 25 °C in an amount of more than 70% by weight, preferably 71 to 90% by weight, more preferably 72 to 80% by weight, based on the total weight of (A)+(B).

[0039] In some embodiments of the present invention, the polyolefin composition has a melt flow rate (MFR) of 0.2 to 6.0 g / 10 min, preferably 0.2 to 2.0 g / 10 min, more preferably 0.2 to 1.5 g / 10 min, even more preferably 0.25 to 1.00 g / 10 min, measured at 230 °C and 2.16 kg according to ISO 1133.

[0040] In some embodiments, the melt flow rate (MFR) of the polyolefin composition measured at 230 °C and 2.16 kg according to ISO 1133 is in the range of 0.2 to 6.0 g / 10 min, preferably 0.2 to 2.0 g / 10 min, more preferably 0.2 to 1.5 g / 10 min, even more preferably 0.25 to 1.00 g / 10 min, and is directly obtained by polymerization.

[0041] In some embodiments, the melt flow rate (MFR) of the polyolefin composition measured at 230 °C and 2.16 kg according to ISO 1133 is 0.2 to 6.0 g / 10 min, preferably 0.2 to 2.0 g / 10 min, more preferably 0.2 to 1.5 g / 10 min, even more preferably 0.25 to 1.00 g / 10 min. It is not obtained by degrading (visbreaking) the polyolefin composition obtained from the polymerization reaction.

[0042] In some embodiments of the present invention, the xylene-soluble fraction (XS(tot)) of the polyolefin composition has an intrinsic viscosity of 2.0 to 5.5 dl / g, preferably 2.5 to 4.5 dl / g, more preferably 3.1 to 3.9 dl / g.

[0043] In some embodiments of the present invention, the polyolefin composition comprises 15-35% by weight, preferably 20-30% by weight, of component (A) and 65-85% by weight, preferably 70-80% by weight, of component (B), where the amounts of (A) and (B) are based on the total weight of (A)+(B).

[0044] In a preferred embodiment of the present invention, the polyolefin composition comprises:

[0045] (A) A copolymer of propylene and 1-hexene, which is 10-40% by weight, 15-35% by weight, preferably 20-30% by weight, contains 1.0-6.0% by weight, preferably 2.0-5.0% by weight, preferably 2.8-4.8% by weight, more preferably 3.0-4.0% by weight of 1-hexene based on the weight of component (A), and has a melt flow rate (MFR A) measured according to ISO 1133 at 230 °C and 2.16 kg of 20 to 60 g / 10 min, preferably 25 to 55 g / 10 min, more preferably 30 to 50 g / 10 min; and

[0046] (B) A copolymer of propylene and ethylene, which is 60-90% by weight, 65-85% by weight, preferably 70-80% by weight, contains 20-35% by weight of ethylene based on the total weight of component (B),

[0047] wherein

[0048] i) the polyolefin composition contains a fraction (XS(tot)) soluble in xylene at 25 °C in an amount higher than 65% by weight, preferably higher than 70% by weight, more preferably 71 to 90% by weight, preferably 72 to 80% by weight;

[0049] ii) the amounts of (A) and (B) and XS(tot) are based on the total weight of (A) + (B); and

[0050] iii) the melt flow rate (MFR) of the polyolefin composition measured according to ISO 1133 at 230 °C and 2.16 kg is 0.2 to 6.0 g / 10 min, preferably 0.2 to 2.0 g / 10 min, preferably 0.2 to 1.5 g / 10 min, preferably 0.25 to 1.00 g / 10 min.

[0051] In some embodiments, the polyolefin composition has at least one of the following properties:

[0052] - A flexural modulus of 50 to 90 MPa, preferably 60 to 85 MPa, more preferably 65 to 80 MPa, measured on injection-molded samples obtained as disclosed in the experimental part according to ISO 178:2019; and / or

[0053] - A Charpy impact at -40 °C of equal to or higher than 6.0 KJ / m 2 measured according to ISO 179 / 1eA2010. In one embodiment, the Charpy impact at -40 °C ranges from 6.0 - 10.0 KJ / m 2 ; and / or

[0054] - Measured on 1 mm thick extruded sheets according to method ISO 527-3 (specimen type 2, crosshead speed: 1 mm / min), the tensile modulus in the MD (machine direction) and / or TD (transverse direction), preferably in both MD and TD, is less than 70.0 MPa, preferably less than 60.0 MPa, more preferably less than 50 MPa. In one embodiment, the tensile modulus in the MD and / or TD, preferably in both MD and TD, is 30.0 - 70.0 MPa, preferably 30.0 - 60.0 MPa; and / or

[0055] - Measured on 1 mm thick extruded sheets according to method ISO527-3 (specimen type: 5, crosshead speed: 500 mm / min), the breaking strength in the MD and / or TD, preferably in both MD and TD, is greater than 14.0 MPa, preferably greater than 15.0 MPa. In one embodiment, the breaking strength in the MD and / or TD, preferably in both MD and TD, is 14.0 - 20.0, preferably 15.0 - 18.0; and / or

[0056] - The puncture resistance measured on 1 mm thick extruded sheets according to ASTM D 4833 method (punch diameter: 8 mm, crosshead speed: 300 mm / min) is greater than 170 N, preferably greater than 200 N. In one embodiment, the puncture resistance is in the range of 170 - 250 N, preferably 200 - 250 N; and / or

[0057] - The Shore A value measured on 1 mm thick extruded sheets according to method ISO868 (15 seconds) is less than 90. In one embodiment, the Shore A value is in the range of 70 - 90; and / or

[0058] - The Shore D value measured on 1 mm thick extruded sheets according to method ISO868 (15 seconds) is equal to or less than 30. In one embodiment, the Shore D value is in the range of 23 - 30.

[0059] In a preferred embodiment of the present invention, the polyolefin composition has a flexural modulus, Charpy impact at -40 °C, breaking strength, tensile modulus, puncture resistance, Shore A and Shore D values included within the above ranges.

[0060] In some embodiments, the polyolefin composition is further imparted with at least one of the following properties measured on injection molded samples:

[0061] - The breaking strength measured according to method ISO527 is greater than or equal to 9.0 MPa. In one embodiment, the breaking strength is 9.0 - 15.0 MPa; and / or

[0062] - Elongation at break, determined according to method ISO527, is included in the range of 350 - 550%; and / or

[0063] - Vicat softening temperature, determined according to method ISO306 (A50), is included in the range of 40°C - 60°C; and / or

[0064] - Shore A value, determined according to method ISO868 (15 seconds), is included in the range of 70 - 90; and / or

[0065] - Shore D value, determined according to method ISO868 (15 seconds), is included in the range of 23 - 30.

[0066] In some embodiments, the polyolefin composition is also imparted with at least one of the following properties measured on an extruded sheet 1 mm thick:

[0067] - Elongation at break in the MD and / or TD, preferably in the MD and TD, determined according to method ISO527 - 3 (specimen type: 5, crosshead speed: 500 mm / min), is included in the range of 600 - 800%; and / or

[0068] - Tear strength in the MD and / or TD, preferably in the MD and TD, determined according to method ASTM D 1004 (crosshead speed: 51 mm / min; V - notched specimens), is included in the range of 40 - 70 g, preferably 50 - 65 g; and / or

[0069] - Puncture deformation measured according to method ASTM D 4833 (punch diameter: 8 mm, crosshead speed: 300 mm / min) is greater than or equal to 40 mm, preferably greater than or equal to 45 mm. In one embodiment, the puncture deformation is included in the range of 40 - 60 mm, preferably 45 - 60 mm.

[0070] In one embodiment, the polyolefin composition has all of the above properties.

[0071] The properties disclosed above are measured on injection - molded and extruded samples obtained as described in the experimental part of the present invention.

[0072] In some preferred embodiments, the polyolefin composition is prepared by sequential polymerization in at least two stages, wherein the second and each subsequent polymerization stage is carried out in the presence of the polymer produced in the previous polymerization stage.

[0073] In some embodiments, the polymerization method for preparing the single components (A) and (B) or the sequential polymerization method for preparing the polyolefin composition is carried out in the presence of a catalyst selected from metallocene compounds, highly stereoselective Ziegler - Natta catalyst systems, and combinations thereof.

[0074] In some preferred embodiments, the polymerization process for preparing the single components (A) and (B) or the sequential polymerization process for preparing the polyolefin composition is carried out in the presence of a highly stereoselective Ziegler-Natta catalyst system, which catalyst system comprises:

[0075] (1) a solid catalyst component comprising a magnesium halide support and a stereoregular internal donor, on which magnesium halide support there is a Ti compound having at least one Ti-halogen bond;

[0076] (2) optionally, but preferably, an aluminum-containing cocatalyst; and

[0077] (3) optionally, but preferably, an additional electron donor compound (external donor).

[0078] In some preferred embodiments, the solid catalyst component (1) comprises a titanium compound of the formula Ti(OR) n X y_n wherein n is comprised between 0 and y; y is the valence of titanium; X is a halogen, and R is a hydrocarbyl group having 1-10 carbon atoms or a -COR group. Particularly preferred among them are titanium compounds having at least one Ti-halogen bond, such as titanium tetrahalide or haloalcoholate. Preferred specific titanium compounds are TiCl3, TiCl4, Ti(OBu)4, Ti(OBu)Cl3, Ti(OBu)2Cl2, Ti(OBu)3Cl. TiCl4 is particularly preferred.

[0079] In one embodiment, the solid catalyst component (1) comprises a titanium compound ensuring a Ti content of 0.5 to 10% by weight relative to the total weight of the solid catalyst component (1).

[0080] The solid catalyst component (1) comprises at least one stereoregular internal electron donor compound selected from mono- or bidentate organic Lewis bases, preferably selected from esters, ketones, amines, amides, carbamates, carbonates, ethers, nitriles, alkoxysilanes and combinations thereof.

[0081] Particularly preferred are electron donors belonging to aliphatic or aromatic mono- or dicarboxylic esters and diethers.

[0082] Among the alkyl and aryl esters of optionally substituted aromatic polycarboxylic acids, preferred donors are esters of phthalic acid, such as those described in EP45977A2 and EP395083A2.

[0083] In some embodiments, the internal electron donor is selected from the group consisting of mono- or disubstituted phthalate esters, wherein the substituents are independently selected from straight-chain or branched C 1-10 alkyl, C 3-8 cycloalkyl and aryl.

[0084] In some preferred embodiments, the internal electron donor is selected from diisobutyl phthalate, di-n-butyl phthalate, di-n-octyl phthalate, diphenyl phthalate, benzyl butyl phthalate, and combinations thereof.

[0085] In one embodiment, the internal electron donor is diisobutyl phthalate.

[0086] Esters of aliphatic acids may be selected from malonic acid, such as those described in WO98 / 056830, WO98 / 056833, WO98 / 056834, glutaric acid, such as those disclosed in WO00 / 55215, and succinic acid, such as those disclosed in WO00 / 63261.

[0087] Particular types of diesters are those esterified from aliphatic or aromatic diols, such as those described in WO2010 / 078494 and USP 7,388,061.

[0088] In some embodiments, the internal electron donor is selected from 1,3-diether of the following formula:

[0089]

[0090] wherein R I and R II are independently selected from C 1-18 alkyl, C 3-18 cycloalkyl, and C 7-18 aryl, R III and R IV are independently selected from C 1-4 alkyl; or the carbon atom at the 2-position of the 1,3-diether belongs to a cyclic or polycyclic structure composed of 5 to 7 carbon atoms, or 5 - n or 6 - n' carbon atoms, and respectively n nitrogen atoms and n' heteroatoms selected from N, O, S, and Si, wherein n is 1 or 2 and n' is 1, 2, or 3, the structure contains two or three degrees of unsaturation (cyclopolyene structure), and is optionally condensed with other cyclic structures, or is substituted by one or more substituents selected from the group consisting of straight-chain or branched-chain alkyls; cycloalkyl, aryl, aralkyl, alkaryl, and halogen, or is fused with other cyclic structures and substituted by one or more of the above substituents, and the substituents may also be bonded to the fused cyclic structure, wherein one or more of the above alkyl, cycloalkyl, aryl, aralkyl, or alkaryl, and the fused cyclic structure optionally contain one or more heteroatoms as substituents for carbon and / or hydrogen atoms. This type of ether is described in EP361493, EP728769, and WO02 / 100904.

[0091] When using the above 1,3-diether, the external electron donor (3) may be absent.

[0092] In some cases, specific mixtures of internal donors, especially aliphatic or aromatic mono- or dicarboxylic esters and 1,3-diether as disclosed in WO07 / 57160 and WO2011 / 061134, can be used as internal donors.

[0093] The preferred magnesium halide support is magnesium dihalide.

[0094] In one embodiment, the amount of internal electron donor immobilized on the solid catalyst component (1) is 5 to 20% by mole relative to magnesium dihalide.

[0095] The preferred method for preparing the solid catalyst component starts from a magnesium dihalide precursor which, when reacted with titanium chloride, converts the precursor into a magnesium dihalide support. This reaction is preferably carried out in the presence of a stereoregulating internal donor.

[0096] In a preferred embodiment, the magnesium dihalide precursor is a Lewis adduct of the formula MgCl2·nR1OH, where n is a number between 0.1 and 6, and R1 is a hydrocarbyl group having 1 - 18 carbon atoms. Preferably, n ranges from 1 to 5, more preferably from 1.5 to 4.5.

[0097] The adduct can be suitably prepared in spherical form by mixing an alcohol and magnesium chloride and operating at the melting temperature (100 - 130 °C) of the adduct under stirring conditions.

[0098] Then, the adduct is mixed with an inert hydrocarbon immiscible with the adduct, thereby producing a rapidly quenched emulsion, resulting in the solidification of the adduct in the form of spherical particles.

[0099] The resulting adduct can be reacted directly with the Ti compound, or it can be pre-treated by thermal controlled dealcoholization (80 - 130 °C) to obtain an adduct in which the molar number of alcohol is generally less than 3, preferably between 0.1 and 2.5.

[0100] As described in EP395083A2, this controlled dealcoholization step can be carried out to increase the morphological stability of the catalyst during polymerization and / or increase the catalyst porosity.

[0101] The reaction with the Ti compound can be carried out by suspending the optionally dealcoholized adduct in cold TiCl4 (usually at 0 °C). The mixture is heated to 80 - 130 °C and held at this temperature for 0.5 - 2 hours. The treatment with TiCl4 can be carried out one or more times. A stereoregulating internal donor can be added during the treatment with TiCl4. The treatment with the internal donor can be repeated one or more times.

[0102] The preparation of the catalyst component according to this general method is described, for example, in European patent applications US4,399,054, US4,469,648, WO98 / 44009A1 and the aforementioned EP395083A2.

[0103] In one embodiment, the catalyst component (1) is in the form of spherical particles having an average diameter of 10 to 350 μm, a surface area of 20 to 250 m 2 / g, preferably 80 - 200 m 2 / g, and a porosity greater than 0.2 ml / g, preferably 0.25 to 0.5 ml / g, wherein the surface area and porosity are measured by BET.

[0104] In some preferred embodiments, the catalyst system comprises an Al-containing cocatalyst (2) selected from trialkyl Al, and the trialkyl Al is preferably selected from the group consisting of triethyl Al, triisobutyl Al, and tri-n-butyl Al.

[0105] In one embodiment, the Al / Ti weight ratio in the catalyst system is from 1 to 1000, preferably from 20 to 800.

[0106] In a preferred embodiment, the catalyst system comprises an additional electron donor compound (3) (external electron donor) selected from silicon compounds, ethers, esters, amines, heterocyclic compounds (especially 2,2,6,6-tetramethylpiperidine), and ketones.

[0107] Preferably, the external donor is selected from silicon compounds of the formula (R2)a(R3)bSi(OR4)c, where 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; R2, R3, and R4 are alkyl, cycloalkyl, or aryl groups having 1 - 18 carbon atoms, optionally containing heteroatoms. Particularly preferred are such silicon compounds where a is 1, b is 1, c is 2, at least one of R2 and R3 is selected from branched alkyl, cycloalkyl, or aryl groups having 3 - 10 carbon atoms, optionally containing heteroatoms, and R4 is a C1 - C10 alkyl group, especially methyl.

[0108] Examples of such preferred silicon compounds are selected from methylcyclohexyldimethoxysilane (C donor), diphenyldimethoxysilane, methyl tert-butyldimethoxysilane, dicyclopentyldimethoxysilane (D donor), diisopropyldimethoxysilane, (2-ethylpiperidyl)tert-butyldimethoxysilane, (2-ethylpiperidyl)tert-hexyldimethoxysilane, (3,3,3-trifluoropropyl)(2-ethylpiperidyl)dimethoxysilane, methyl(3,3,3-trifluoropropyl)dimethoxysilane, and combinations thereof.

[0109] Also preferred are the following silicon compounds, where a is 0, c is 3, R3 is a branched alkyl or cycloalkyl optionally containing a heteroatom, and R4 is methyl. Examples of such preferred silicon compounds are cyclohexyltrimethoxysilane, tert-butyltrimethoxysilane, and hexyltrimethoxysilane.

[0110] Even if several combinations of the components of the catalyst system allow obtaining the polyolefin composition of the present invention, a particularly suitable catalyst system comprises diisobutyl phthalate as the internal electron donor and dicyclopentyldimethoxysilane (D-donor) as the external electron donor (3).

[0111] In one embodiment, the catalyst system is pre-contacted (pre-polymerized) with a small amount of olefin, the catalyst is maintained in a suspension in a hydrocarbon solvent, and polymerization is carried out at a temperature of 25 °C to 60 °C, producing an amount of polymer about 0.5 to about 3 times the weight of the catalyst system.

[0112] In an alternative embodiment, the pre-polymerization is carried out in a liquid monomer, producing a polymer in an amount 1000 times the weight of the catalyst system.

[0113] The sequential polymerization method for preparing the polyolefin composition of the present invention is described in EP472946 and WO03 / 011962, the contents of which are incorporated herein by reference for reference purposes.

[0114] Components (A) and (B) can be prepared in any one of the polymerization stages.

[0115] In one embodiment, the polymerization method comprises a polymerization stage carried out in the presence of a highly stereoselective Ziegler-Natta catalyst system, wherein:

[0116] (a) In a first copolymerization stage, the polymerization monomers are polymerized to form a propylene copolymer (A); and

[0117] (b) In a second copolymerization stage, the relevant monomers are polymerized to form a propylene copolymer (B).

[0118] In one embodiment, the second copolymerization stage (b) comprises a copolymerization stage (b1) and a copolymerization stage (b2), wherein the comonomers are polymerized to form a propylene copolymer (B1) in stage (b1) and a copolymer (B2) in stage (b2).

[0119] In one embodiment, the second copolymerization stage (b) comprises a copolymerization stage (b1) and a copolymerization stage (b2), wherein the propylene copolymer (B2) is formed in the copolymerization stage (b1) and the propylene copolymer (B1) is formed in the polymerization stage (b2).

[0120] The polymerization, which can be continuous or batch, can be carried out according to known cascade techniques in a mixed liquid phase / gas phase or entirely in the gas phase.

[0121] The liquid-phase polymerization can be slurry, solution or bulk (liquid monomer). The latter technique is most preferred and can be carried out in various types of reactors, such as continuous stirred tank reactors, loop reactors or plug flow reactors.

[0122] The gas-phase polymerization stage can be carried out in a gas-phase reactor, such as a fluidized bed or a stirred fixed bed reactor.

[0123] In one embodiment, the copolymerization stage (a) is carried out in the liquid phase using liquid propylene as a diluent, and the copolymerization stage (b) or copolymerization stages (b1) and (b2) are carried out in the gas phase.

[0124] In a preferred embodiment, the copolymerization step (a) is also carried out in the gas phase.

[0125] In one embodiment, the reaction temperatures of the polymerization stages (a), (b), (b1) and (b2) are independently selected from values including those in the range of 40 °C to 90 °C.

[0126] In one embodiment, the polymerization pressure of the copolymerization stage (a) carried out in the liquid phase is 3.3 to 4.3 MPa.

[0127] In one embodiment, the polymerization pressures of the copolymerization stages (a), (b), (b1) and (b2) carried out in the gas phase are independently selected from values of 0.5 to 3.0 MPa.

[0128] The residence time of each polymerization stage depends on the desired ratio of components (A) and (B) or components (A), (B1) and (B2) of the polyolefin composition.

[0129] In one embodiment, the residence time in each polymerization stage is 15 minutes to 8 hours.

[0130] When the polyolefin composition of the present invention is prepared by a continuous polymerization method, the amounts of components (A) and (B) or components (A), (B1) and (B2) correspond to the split between polymerization reactors.

[0131] The molecular weight of the propylene copolymer obtained in the polymerization stage is adjusted using a chain transfer agent such as hydrogen or ZnEt2.

[0132] In some preferred embodiments of the present invention, the polyolefin composition is blended with additives at the end of the polymerization reaction.

[0133] In one embodiment, the polyolefin composition is an additive-containing polyolefin composition (AD1) that contains, based on the total weight of the additive-containing polyolefin composition (AD1), up to 0.3% by weight, preferably from 0.01 to 0.3% by weight, in total, of at least one first additive (C) of the type used in the polyolefin field, the first additive being selected from the group consisting of antistatic agents, antioxidants, acid scavengers, melt stabilizers, and combinations thereof.

[0134] In one embodiment, the polyolefin composition is an additive-containing polyolefin composition (AD1) composed of component (A), component (B), and at least one first additive (C), preferably in the amounts as described above.

[0135] In some embodiments, the polyolefin composition further contains at least one second additive (D), the second additive (D) being selected from the group consisting of fillers, pigments, nucleating agents, extender oils, flame retardants (such as aluminum trihydrate), anti-UV agents (such as titanium dioxide), UV stabilizers, lubricants (such as oleamide), anti-blocking agents, waxes, coupling agents for fillers, and combinations thereof, the second additive (D) being known in the polymer compounding field.

[0136] In one embodiment, the additive-containing polyolefin composition contains up to 50% by weight, preferably from 0.01 to 50% by weight, more preferably from 0.5 to 30% by weight, of at least one second additive (D), the amount of at least one second additive (D) being based on the total weight of the additive-containing polyolefin composition.

[0137] In some embodiments, the polyolefin composition is an additive-containing polyolefin composition (AD2) that contains the above-described polyolefin composition and (C) up to 0.3% by weight, preferably from 0.01 to 0.3% by weight, of at least one first additive; and (D) up to 50% by weight, preferably from 0.01 to 50% by weight, more preferably from 0.5 to 30% by weight, of at least one second additive,

[0138] wherein the amounts of (A) and (B) are based on the total weight of (A)+(B), and the amounts of the first additive (C) and the second additive (D) are based on the total weight of the additive-containing polyolefin composition (AD2).

[0139] In one embodiment, the first additive (C) and the second additive (D) are selected from the above group.

[0140] In one embodiment, the additive-containing polyolefin composition (AD2) consists of components (A), (B), (C), and (D).

[0141] The physical and mechanical properties of the polyolefin composition make it suitable for the production of sheets or films.

[0142] Therefore, another object of the present invention is a sheet or film comprising the polyolefin composition as described above.

[0143] In one embodiment, the sheet or film comprises a polyolefin with additives (AD1) or a polyolefin composition with additives (AD2).

[0144] In some embodiments, the total thickness of the sheet or film is 1000 - 2000 μm, preferably 1200 - 1800 μm.

[0145] The sheet or film is a single - layer or multi - layer sheet or film.

[0146] In one example, the sheet or film is a single - layer sheet or film comprising a polyolefin composition or a polyolefin composition with additives (AD1) or a polyolefin composition with additives (AD2).

[0147] In one embodiment, the single - layer sheet or film consists of a polyolefin composition or a polyolefin composition with additives (AD1) or a polyolefin composition with additives (AD2).

[0148] In some examples, the sheet or film is a multi - layer sheet or film comprising at least one layer X, wherein layer X comprises a polyolefin composition or a polyolefin composition with additives (AD1) or a polyolefin composition with additives (AD2).

[0149] In one embodiment, layer X contained in the multi - layer sheet or film consists of a polyolefin composition or a polyolefin composition with additives (AD1) or a polyolefin composition with additives (AD2).

[0150] In one embodiment, the multi - layer sheet or film comprises layer X and layer Y, wherein layer X and layer Y independently comprise a polyolefin selected from the group consisting of a polyolefin composition, a polyolefin composition with additives (AD1), and a polyolefin composition with additives (AD2).

[0151] In one embodiment, the multi - layer sheet or film comprises layer X and layer Y, wherein layer X and layer Y consist of a polyolefin independently selected from the group consisting of a polyolefin composition, a polyolefin composition with additives (AD1), and a polyolefin composition with additives (AD2).

[0152] In one embodiment, the multi - layer sheet or film consists of layer X and layer Y, wherein layer X and layer Y independently comprise a polyolefin selected from the group consisting of a polyolefin composition, a polyolefin composition with additives (AD1), and a polyolefin composition with additives (AD2).

[0153] In one embodiment, the multilayer sheet or film consists of layer X and layer Y, wherein layer X and layer Y are composed of polyolefins independently selected from the group consisting of polyolefin compositions, polyolefin compositions with added additives (AD1), and polyolefin compositions with added additives (AD2).

[0154] In one embodiment, the multilayer sheet or film has a layer structure X / Z / Y, wherein layer X and layer Y are as described above, and layer Z is a reinforcing layer containing a plastic material selected from the group consisting of: propylene homopolymer, propylene copolymer, polyethylene, polyethylene terephthalate, and combinations thereof.

[0155] In one embodiment, layer Z is a woven fabric or a nonwoven fabric.

[0156] The single-layer sheet or film can be obtained by calendering, extrusion, or spread coating. In a preferred embodiment, the sheet or film is obtained by extrusion.

[0157] The multilayer sheet or film can be obtained by coextruding the polyolefins contained in the layers or by laminating the layers.

[0158] In one embodiment, the sheet or film is a single-layer roof sheet or film.

[0159] In one embodiment, the sheet or film is a geomembrane.

[0160] The features characterizing the subject matter of the present invention are not linked to each other without extension. Thus, a particular level of preference for one feature does not necessarily involve the same level of preference for the remaining features. Furthermore, it forms part of the present invention, any combination of parameter ranges and / or features, even if not explicitly described.

[0161] Examples

[0162] The following examples are merely illustrative and are not intended to limit the scope of the present invention in any way.

[0163] Characterization methods

[0164] The following methods are used to determine the properties indicated in the specification, claims, and examples.

[0165] The melt flow rate is determined according to method ISO1133 (230 °C, 2.16 kg).

[0166] Solubility in xylene at 25 °C: 2.5 g of the polymer sample and 250 ml of xylene were introduced into a glass flask equipped with a refrigerator and a magnetic stirrer. The temperature was raised to 135 °C within 30 minutes. The resulting clear solution was kept under reflux and stirred for another 30 minutes. The solution was cooled in two stages. In the first stage, the temperature was lowered to 100 °C in air with stirring for 10 to 15 minutes. In the second stage, the flask was transferred to a thermostatically controlled water bath at 25 °C for 30 minutes. The temperature was lowered to 25 °C without stirring during the first 20 minutes and maintained at 25 °C with stirring during the last 10 minutes. The solid formed was filtered on a fast filter paper (e.g., Whatman filter paper grade 4 or 541). 100 ml of the filtrate (S1) was poured into a pre-weighed aluminum container, and the aluminum container was heated to 140 °C on a hot plate under a nitrogen stream to remove the solvent by evaporation. Then the container was kept in an oven at 80 °C under vacuum until a constant weight was obtained. Then the polymer soluble in xylene at 25 °C was calculated. The XS(tot) and XS A values were determined experimentally. The fraction (XS B ) of the component (B) soluble in xylene at 25 °C can be calculated by the following formula:

[0167] XS = w(A) × X(XS A ) + W(B) × X(XS B )

[0168] where W(A) and W(B) are the relative amounts of components (A) and (B), respectively, and W(A) + W(B) = 1.

[0169] Intrinsic viscosity of the xylene-soluble fraction: To calculate the value of the intrinsic viscosity IV, the flow time of the polymer solution was compared with the flow time of the solvent (THN). A Ubbelohde-type glass capillary viscometer was used. The oven temperature was adjusted to 135 °C. The temperature had to be stable (135 ° ± 0.2 °C) before starting the measurement of the solvent flow time t0. The detection of the sample meniscus of the viscometer was carried out by an optoelectronic device.

[0170] Sample Preparation Pour 100 ml of the filtrate (S1) into a beaker and add 200 ml of acetone with vigorous stirring. The precipitation of the insoluble fraction must be complete, as confirmed by clear solid-solution separation. Filter the suspension through a weighed metal sieve (200 mesh), rinse the beaker and wash the precipitate with acetone to completely remove o-xylene. Dry the precipitate in a vacuum oven at 70 °C until a constant weight is reached. Weigh 0.05 g of the precipitate and dissolve it in 50 ml of tetralin (THN) at a temperature of 135 °C. Measure the efflux time t of the sample solution using the Huggins equation (Huggins, M.L., J. Am. Chem. Soc. 1942, 64, 11, 2716 - 2718) and the following data, and convert it to the intrinsic viscosity value [η]:

[0171] - Concentration of the sample (g / dl);

[0172] - Density of the solvent at a temperature of 135 °C;

[0173] - Flow time t0 of the solvent on the same viscometer at a temperature of 135 °C. Use a single polymer solution to determine [η].

[0174] Comonomer Content: Determined by IR using a Fourier transform infrared spectrometer (FTIR). The spectrum of the polymer pressed film is recorded with absorbance against wave number (cm -1 )). The following measured values are used to calculate the ethylene and 1-hexene contents:

[0175] The combined absorption band region (At) between 4482 and 3950 cm -1 which is used for spectral determination standardization of the film thickness;

[0176] - Subtract the linear baseline and eliminate the remaining constant offset in the range of 790 - 660 cm -1 ;

[0177] - The contents of ethylene and 1-hexene are obtained by applying partial least squares (PLS1) multiple regression to the range of 762 - 688 cm -1 .

[0178] Calibrate this method by using a polymer standard based on 13C NMR analysis. For sample preparation, use a hydraulic press to obtain a thick sheet by pressing about 1 g of the sample between two aluminum foils. The pressing temperature is 180 ± 10 °C (356 °F), the pressure is about 10 kg / cm 2 , for about one minute (at least two pressing operations for each sample). Cut a small portion from the sheet to mold a film. The recommended film thickness range is 0.02 - 0.05 cm.

[0179] Injection-molded samples: Samples measuring 80×10×4 mm were obtained according to method ISO 1873-2:2007.

[0180] Flexural modulus: Measured on injection-molded samples according to method ISO 178:2019.

[0181] Strength and elongation at break: Measured on injection-molded samples according to method ISO527.

[0182] Shore A and D on injection-molded samples: Measured according to method ISO868 (15 seconds).

[0183] Vicat softening temperature: Measured on injection-molded samples according to method ISO 306 (A50).

[0184] Charpy impact test at -40 °C: Measured on injection-molded samples according to ISO179 / 1eA2010.

[0185] Preparation of extruded samples: The polymer in pellet form was fed through a feed hopper into a Leonard extruder (single-screw extruder, diameter 40 mm and length 27 L / D), where the polymer was first melted (melting temperature 230 °C), compressed, mixed, and finally metered out at a throughput rate of 10 Kg / h using a metering pump (15 cc / rpm). The molten polymer left a flat die (width 200 mm, die lip 0.8 - 0.9 mm) and was immediately cooled by a vertical three-roll calender with a roll temperature of 60 °C. An extruded sheet 1 mm thick was obtained.

[0186] Tensile modulus (MD and TD): Measured on 1-mm-thick extruded sheets according to method ISO527-3. Sample type 2, crosshead speed: 1 mm / min.

[0187] Tensile strength and elongation at break (MID and TD): Measured on 1-mm-thick extruded sheets according to method ISO527-3. Sample type: 5, crosshead speed: 500 mm / min.

[0188] Tear resistance: Measured on 1-mm-thick extruded sheets according to method ASTM D 1004. Crosshead speed: 51 mm / min; V-shaped die-cut samples.

[0189] Puncture resistance and deformability: Measured on 1-mm-thick extruded sheets according to method ASTM D 4833. Punch diameter 8 mm, crosshead speed: 300 mm / min.

[0190] Shore A and D on extruded sheets: Measured on 1-mm-thick extruded sheets according to method ISO868 (15 seconds).

[0191] Examples 1-2 and Comparative Example 3

[0192] The polymerization is carried out in two gas-phase reactors connected in series and equipped with means for transferring the product from the first reactor to the second reactor. For the polymerization, a Ziegler-Natta catalyst system is used, which comprises:

[0193] - a titanium-containing solid catalyst component prepared by the procedure described in Example 3 of EP395083, according to which diisobutyl phthalate is used as the internal electron donor compound;

[0194] - triethylaluminum (TEAL) as the cocatalyst;

[0195] - dicyclopentyldimethoxysilane (DCPMS) as the external electron donor.

[0196] The solid catalyst component is contacted with TEAL and DCPMS in a pre-contact vessel, and the weight ratio of TEAL to the solid catalyst component is 4 - 5. The weight ratio TEAL / DCPMS (T / D) is reported in Table 1.

[0197] Then the catalyst system is subjected to prepolymerization by maintaining it in a suspension in liquid propylene at 20 °C for about 30 - 32 minutes before introducing it into the first polymerization reactor.

[0198] The propylene copolymer (A) is prepared by feeding all of the prepolymerized catalyst system, hydrogen (used as a molecular weight regulator), and propylene and comonomer (hexene-1 or ethylene) in the gas phase continuously and at a constant flow rate into the first gas-phase reactor.

[0199] The propylene copolymer (A) from the first reactor is discharged in a continuous stream, and after the unreacted monomers have been removed, it is introduced into the second gas-phase reactor in a continuous stream together with a constant and quantified amount of propylene, ethylene, and hydrogen all in the gaseous state. The propylene copolymer (B) is produced in the second reactor.

[0200] The polymerization conditions, the molar ratios of the reactants, and the composition of the resulting copolymers are shown in Table 1.

[0201] Table 1 - Polymerization Conditions

[0202]

[0203] Remarks: C2- = ethylene in the gas phase (IR); C3- = propylene in the gas phase (IR); C6- = hexene-1 in the gas phase (IR); Split = the amount of polymer produced in the relevant reactor.

[0204] *Calculated value.

[0205] The polymer particles exiting the second reactor are steam-treated to remove unreacted monomers and volatile compounds and then dried.

[0206] The polyolefin composition thus obtained is extruded with additive (C) in a twin-screw extruder Berstorff ZE25 (length / diameter ratio of the screw: 34) under nitrogen atmosphere under the following conditions:

[0207] Rotational speed: 250 rpm;

[0208] Extruder output: 15 kg / hour;

[0209] Melt temperature: 245 °C.

[0210] The additives added to the polyolefin composition are:

[0211] - 0.1% by weight of 1010;

[0212] - 0.1% by weight of 168;

[0213] - 0.05% by weight of DHT-

[0214] wherein the amounts of the additives are relative to the total weight of the polyolefin composition containing additive (C).

[0215] 1010 is 2,2-bis[3-[,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropoxy]methyl]-1,3-propanediyl-3,5-bis(1,1-dimethylethyl)-4-hydroxybenzenepropionate; 168 is tris(2,4-di-tert-butylphenyl) phosphite; DHT- is aluminum magnesium hydroxide carbonate (hydrate).

[0216] The properties of the materials tested on injection-molded samples are reported in Table 3. The properties of the materials tested on extruded sheets are reported in Table 4.

[0217] Comparative Example 4

[0218] A polyolefin composition is prepared using the same catalyst system as in Example 1 in three gas-phase reactors connected in series and equipped with means for transferring the product from one reactor to the subsequent reactor.

[0219] The propylene copolymer (A) is prepared by feeding a prepolymerization catalyst system, hydrogen (used as a molecular weight regulator), and propylene and propylene or ethylene all in gaseous phase into a first gas-phase reactor at a continuous and constant flow rate. The propylene copolymer (A) from the first reactor is discharged in a continuous flow, and after removing unreacted monomers, it is introduced into a second gas-phase reactor in a continuous flow together with a quantitatively constant flow of hydrogen and ethylene all in gaseous state. The propylene copolymer (B1) is prepared in the second reactor. The product from the second reactor is discharged in a continuous flow, and after removing unreacted monomers, it is introduced into a third gas-phase reactor in a continuous flow together with a quantitatively constant flow of hydrogen, ethylene, and propylene all in gaseous state. The ethylene-propylene polymer (B2) is produced in the third reactor.

[0220] The polymerization conditions, molar ratios of reactants, and compositions of the resulting copolymers are shown in Table 2.

[0221] Table 2 - Polymerization Conditions

[0222]

[0223] Remarks: C2- = ethylene in the gas phase (IR); C3- = propylene in the gas phase (IR); Split = amount of polymer produced in the relevant reactor. *Calculated value.

[0224] The polymer particles leaving the third reactor are steam-treated to remove unreacted monomers and volatile compounds, dried, and melt-mixed with additives as described in Example 1.

[0225] The properties of the materials tested on injection-molded samples are reported in Table 3. The properties of the materials tested on extruded sheets are reported in Table 4.

[0226] Table 3 - Characterization of Injection-Molded Samples

[0227]

[0228] (**) The polyolefin is cracked with 170 ppm of peroxide to increase the MFR and make it processable using an existing technology extruder for producing sheets or films.

[0229] Table 4 - Characterization of Extruded Sheets

[0230]

[0231] (**) The polyolefin is cracked with 170 ppm of peroxide to increase the MFR and make it processable using an existing technology extruder for producing sheets or films.

Claims

1. A polyolefin composition, comprising: (A) 10 to 40% by weight of a copolymer of propylene and 1-hexene, the copolymer comprising, based on the weight of (A), 2.8 to 6.0% by weight of units derived from 1-hexene and having a melt flow rate (MFR) measured according to ISO 1133 at 230 °C and 2.16 kg in the range of 20 to 60 g / 10 min A ); and (B) 60 - 90% by weight of a copolymer of propylene with at least one α-olefin of the formula CH2=CHR and an optional diene, where R is H or a linear or branched C2 - C8 alkyl group, and where the copolymer comprises 20 - 35% by weight of the α-olefin based on the total weight of (B), where the polyolefin composition comprises an amount of the fraction soluble in xylene at 25°C (XS(tot)) equal to or higher than 65% by weight, and the amounts of (A), (B) and XS(tot) are based on the total weight of (A)+(B).

2. The polyolefin composition according to claim 1, where based on the weight of component (A), component (A) comprises 2.8 - 4.8% by weight of 1-hexene.

3. The polyolefin composition as claimed in claim 1, wherein the copolymer (A) has a melt flow rate (MFR A ) measured according to ISO 1133, at 230 °C and 2.16 kg of from 25 to 55 g / 10 min.

4. The polyolefin composition according to claim 1, wherein the component (A) comprises, based on the weight of the component (A), an amount of less than 12.0% by weight of the fraction soluble in xylene at 25 °C (XS A ).

5. The polyolefin composition according to claim 1, which comprises an amount of the fraction soluble in xylene at 25°C (XS(tot)) of 71 to 90% by weight based on the total weight of (A)+(B).

6. The polyolefin composition according to claim 1, which has a melt flow rate (MFR) of 0.2 to 6.0 g / 10 min measured at 230°C and 2.16 kg according to ISO 1133.

7. The polyolefin composition according to claim 1, where the fraction soluble in xylene at 25°C (XS(tot)) has an intrinsic viscosity of 2.0 to 5.5 dl / g.

8. The polyolefin composition according to claim 1, where the at least one α-olefin comprised in the copolymer (B) is selected from the group consisting of: ethylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene and combinations thereof.

9. The polyolefin composition according to claim 1, which comprises: (A) 10 - 40% by weight of a copolymer of propylene and 1 - hexene, which contains 2.8 - 6.0% by weight of 1 - hexene based on the weight of component (A), and has a melt flow rate (MFR) measured according to ISO 1133, at 230 °C and 2.16 kg of 20 to 60 g / 10 min A ); and (B) 60 - 90% by weight of a copolymer of propylene and ethylene, which comprises 20 - 35% by weight of ethylene based on the total weight of component (B), where i) the polyolefin composition comprises an amount of the fraction soluble in xylene at 25°C (XS(tot)) of 71 to 90% by weight; ii) the amounts of (A), (B) and XS(tot) are based on the total weight of (A)+(B); and iii) the melt flow rate (MFR) of the polyolefin composition measured at 230°C and 2.16 kg according to ISO 1133 is 0.2 to 6.0 g / 10 min.

10. The polyolefin composition according to claim 1, which has at least one of the following properties: - a flexural modulus of 50 to 90 MPa measured on an injection molded sample according to ISO 178:2019; and / or - Charpy impact at -40 °C equal to or higher than 6.0 KJ / m measured according to ISO 179 / 1eA 2010; and / or 2 ​ - a tensile modulus of less than 70.0 MPa in the longitudinal (MD) and / or transverse (TD) directions, determined on a 1 mm thick extruded sheet according to method ISO 527 - 3, sample type 2, crosshead speed: 1 mm / min; and / or - Determined on an extruded sheet 1 mm thick according to method ISO 527-3, sample type: 5, crosshead speed: 500 mm / min, a breaking strength greater than 14.0 MPa in the longitudinal and / or transverse direction; and / or - Determined on an extruded sheet 1 mm thick according to method ASTM D 4833, punch diameter: 8 mm, crosshead speed: 300 mm / min, a puncture resistance greater than 170 N; and / or - A Shore A value below 90 determined on an extruded sheet 1 mm thick according to method ISO 868 for 15 seconds; and / or - A Shore D value equal to or below 30 determined on an extruded sheet 1 mm thick according to method ISO 868 for 15 seconds.

11. A sheet or film comprising the polyolefin composition as claimed in claim 1.

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