Polyolefin composition for roofing applications

Abstract

A soft polyolefin composition for the production of a sheet or film, the polyolefin composition comprising: (A) 18-35 wt.% of a copolymer of propylene with at least one alpha-olefin, wherein the copolymer contains 2.0-4.0 wt.% of alpha-olefin, the amount of alpha-olefin being based on the weight of (A) and having a melt flow rate (MFR A ) of 30-60 g / 10 min; and (B) 65-82 wt.% of a copolymer of propylene with at least one alpha-olefin and optionally a diene, the copolymer comprising 20-35 wt.% of alpha-olefin, the amount of alpha-olefin being based on the weight of (B), wherein - the polyolefin composition comprises the fraction soluble in xylene at 25°C (XS(tot)) in an amount higher than 70 wt.%; - (A), (B) and the amount of fraction soluble in xylene at 25°C (XS(tot)) are based on the total weight of the polyolefin composition; and - the polyolefin composition has a melt flow rate (MFR) of 0.2 to 2.0 g / 10 min.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a thermoplastic polyolefin composition which can be used to prepare a sheet or film having high resistance to puncture and deformation, while maintaining softness and good mechanical properties. The sheet or film has a favorable balance of properties to be used as a geomembrane or for roofing applications. BACKGROUND

[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 are used to prepare heat-weldable thermoplastic roofing sheets. However, PVC requires plasticizers to have the flexibility required for roofing applications. The aging of the film by loss of plasticizers and the presence of chlorine in the polymer chain are the driving factors to replace PVC by chlorine-free thermoplastic polyolefins with the required mechanical properties in the absence of plasticizers.

[0004] Heterophasic polyolefin compositions are used to prepare sheets or films for roofing applications, which are heat-weldable, have suitable mechanical properties and are 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 copolymers of propylene with ethylene and copolymers of ethylene with a-olefins.

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

[0007] A highly inert multilayer 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 with C3-C10 a-olefins. The top layer (B) comprises an ethylene homopolymer or copolymer having a density of 0.915 to 0.980 g / cm 3

[0008] ​In the present context, there is still a need for polyolefin compositions having a proper balance of physical and mechanical properties and good processability, which are particularly suitable for the preparation of a sheet or film which retains softness and has good puncture and tear resistance. SUMMARY

[0009] The present disclosure provides a polyolefin composition comprising:

[0010] (A) 18-35 wt.% of a copolymer of propylene with at least one a-olefin of the formula CH2=CHR, wherein R is H or a linear or branched C2-C3 alkyl group, wherein

[0011] i) the copolymer contains 2.0-4.0 wt.% of at least one a-olefin, the amount of a-olefin being based on the total weight of (A); and

[0012] ii) the propylene copolymer has a melt flow rate (MFR) measured according to ISO 1133, 230°C, 2.16 kg in the range of 30 to 60 g / 10 min, A ; and

[0013] (B) 65-82 wt.% of a copolymer of propylene with at least one a-olefin of the formula CH2=CHR and optionally a diene, wherein R is H or a linear or branched C2-C8 alkyl group, and wherein the copolymer comprises 20-35 wt.% of a-olefin, the amount of a-olefin being based on the total weight of (B),

[0014] wherein

[0015] iii) the polyolefin composition comprises a fraction soluble in xylene at 25°C (XS(tot)) in an amount higher than 70 wt.%;

[0016] iv) the amounts of (A), (B) and the fraction soluble in xylene at 25°C (XS(tot)) are based on the total weight of the polyolefin composition, the total weight being 100; and

[0017] v) the melt flow rate (MFR) of the polyolefin composition measured according to ISO 1133, 230°C, 2.16 kg is 0.2 to 2.0 g / 10 min.

[0018] The present disclosure also provides a sheet or film comprising a polyolefin composition comprising:

[0019] (A) 18-35 wt.% of a copolymer of propylene with at least one a-olefin of the formula CH2=CHR, wherein R is H or a linear or branched C2-C3 alkyl group, wherein

[0020] i) the copolymer contains 2.0 - 4.0 wt.% of at least one alpha-olefin, the amount of alpha-olefin being based on the total weight of (A); and

[0021] ii) the propylene copolymer has a melt flow rate (MFR) measured according to ISO 1133, 230°C, 2.16 kg in the range of 30 to 60 g / 10 min A ; and

[0022] (B) 65 - 82 wt.% of a copolymer of propylene with at least one alpha-olefin of the formula CH2=CHR, wherein R is H or a linear or branched C2-C8 alkyl group, and optionally a diene, and wherein the copolymer comprises 20 - 35 wt.% of alpha-olefin, the amount of alpha-olefin being based on the total weight of (B),

[0023] wherein

[0024] iii) the polyolefin composition comprises the fraction soluble in xylene at 25°C (XS(tot)) in an amount higher than 70 wt.%;

[0025] iv) the amounts of (A), (B) and the fraction soluble in xylene at 25°C (XS(tot)) are based on the total weight of the polyolefin composition, the total weight being 100; and

[0026] v) the melt flow rate (MFR) of the polyolefin composition measured according to ISO 1133, 230°C, 2.16 kg is in the range of 0.2 to 2.0 g / 10 min.

[0027] The polyolefin composition of the present disclosure shows a good balance of mechanical properties, in particular flexibility and softness, while maintaining good elasticity and toughness at low temperatures.

[0028] The polyolefin composition also has high puncture and tear resistance.

[0029] The polyolefin composition has reduced stickiness, thus it is easy to process into a sheet or film, in particular a sheet or film suitable for roofing applications.

[0030] The sheet or film comprising the polyolefin composition of the present disclosure is soft and flexible, easy to install, and has significant puncture and tear resistance.

[0031] While several embodiments have been disclosed, other embodiments will become apparent to those skilled in the art from the following detailed description.

[0032] As will be apparent, certain embodiments as disclosed herein can be modified in various obvious respects which will be appreciated by those skilled in the art without departing from the spirit and scope of the claims presented herein. Accordingly, the following detailed description is not to be taken in a limiting sense and the scope of the embodiments disclosed herein are only limited by the claims presented. DETAILED DESCRIPTION

[0033] In a preferred embodiment, component (A) is a copolymer of propylene with ethylene.

[0034] In one embodiment, component (A) is a propylene copolymer comprising 3.0-3.9 wt.% of at least one alpha-olefin, preferably the propylene copolymer comprises 3.0-3.9 wt.% of ethylene.

[0035] In some embodiments, the propylene copolymer (A) has a melt flow rate (MFR A ) measured according to ISO 1133, 230°C, 2.16 kg of 35-50 g / 10 min, preferably 40-50 g / 10 min, more preferably 42-48 g / 10 min.

[0036] In some embodiments, the propylene copolymer (A) comprises a fraction soluble in xylene at 25°C (XS A ) in an amount lower than 9.0 wt.%, preferably the xylene soluble fraction XS A is comprised in the range of 4.0-9.0 wt.%, more preferably 6.0-8.0 wt.%, the amount of XS A is based on the weight of the copolymer (A).

[0037] In some embodiments, the propylene copolymer (B) comprises a fraction soluble in xylene at 25°C (XS B ) in an amount higher than 80 wt.%, preferably higher than 85 wt.%, more preferably higher than 90 wt.%, the amount of XS B is based on the weight of the copolymer (B).

[0038] In one embodiment, the upper limit of the amount of the fraction soluble in xylene at 25°C (XS B ) of component (B) is 97 wt.%, the amount of XS B is based on the weight of the copolymer (B).

[0039] In some embodiments, component (B) comprises a first copolymer (B1) and a second copolymer (B2) of propylene with at least one alpha-olefin of the formula CH2=CHR and optionally a diene, wherein R is H or a linear or branched C2-C8 alkyl group, with the proviso that the total amount of alpha-olefins comprised in the propylene copolymer (B) is in the range of 20-35 wt.%, the total amount of alpha-olefins being based on the weight of component (B).

[0040] In one embodiment, component (B) comprises:

[0041] (B1 ) 30 to 60 wt.%, preferably 40 to 55 wt.% of a first copolymer of propylene with at least one a-olefin of the formula CH2=CHR, wherein R is H or a linear or branched C2-C8-alkyl radical, and optionally a diene, and wherein the first propylene copolymer comprises 20 to 40 wt.%, preferably 25 to 35 wt.% of a-olefin and more than 80 wt.%, preferably more than 85 wt.%, more preferably more than 90 wt.% of a fraction soluble in xylene at 25°C (XS B1 ), a-olefin and XS B1 in an amount based on the weight of component (B1 ); and

[0042] (B2) 40 to 70 wt.%, preferably 45 to 60 wt.% of a second copolymer of propylene with at least one a-olefin of the formula CH2=CHR, wherein R is H or a linear or branched C2-C8-alkyl radical, and optionally a diene, and wherein the second propylene copolymer comprises 25 to 45 wt.%, preferably 30 to 43 wt.% of a-olefin and more than 80 wt.%, preferably more than 85 wt.%, more preferably more than 90 wt.% of a fraction soluble in xylene at 25°C (XS B2 ), a-olefin and XS B2 in an amount based on the weight of component (B2),

[0043] wherein the amounts of (B1 ) and (B2) are based on the total weight of component (B), which is 100 by weight.

[0044] In one embodiment, for each lower limit, the upper limit of the amount of the fraction of component (B1 ) and / or component (B2) soluble in xylene at 25°C (XS B1 and / or XS B2 ) is 97 wt.%, XS B1 and XS B2 in an amount based on the weight of component (B1 ) and (B2), respectively.

[0045] In one embodiment, for each lower limit, the upper limit of XS B1 and XS B2 is 97 wt.%, XS B1 and XS B2 in an amount based on the weight of component (B1 ) and (B2), respectively.

[0046] In some embodiments, the at least one alpha-olefin comprised in components (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 preferred embodiments, the alpha-olefin is ethylene.

[0047] Optionally, the propylene copolymer (B) and / or (B1) and / or (B2) comprises repeating units derived from a diene, preferably independently selected from the group consisting of butadiene, 1,4-hexadiene, 1,5-hexadiene, ethylidene-1- norbornene and combinations thereof.

[0048] In some embodiments, the total amount of repeating units derived from a diene comprised in the propylene copolymer (B), (B1) and / or (B2) is in the range of 1 to 10 wt.%, the amount of repeating units derived from a diene being based on the weight of component (B) relative to the relevant component.

[0049] In some embodiments of the present disclosure, the polyolefin composition comprises a total amount of a fraction soluble in xylene at 25 °C (XS(tot)) in the range of 70 to 90 wt.%, preferably 70 to 80 wt.%, the amount of XS(tot) being based on the total weight of the polyolefin composition.

[0050] In some embodiments of the present disclosure, the polyolefin composition has a melt flow rate (MFR) measured according to ISO 1133, 230 °C, 2.16 kg in the range of 0.3 to 1.5 g / 10 min, preferably 0.4 to 1.0 g / 10 min.

[0051] In some embodiments of the present disclosure, the polyolefin composition has a melt flow rate (MFR) measured according to ISO 1133, 230 °C, 2.16 kg in the range of 0.2 to 2.0 g / 10 min, preferably 0.3 to 1.5 g / 10 min, more preferably 0.4 to 1.0 g / 10 min, obtained directly from polymerization.

[0052] In some embodiments of the present disclosure, the polyolefin composition has a melt flow rate (MFR) measured according to ISO 1133, 230 °C, 2.16 kg in the range of 0.2 to 2.0 g / 10 min, preferably 0.3 to 1.5 g / 10 min, more preferably 0.4 to 1.0 g / 10 min, obtained directly from polymerization.

[0053] In some embodiments of the present disclosure, the fraction soluble in xylene at 25 °C (XS(tot)) of the polyolefin composition has an intrinsic viscosity (XS(IV)) in the range of 2.5 to 4.5 dl / g, preferably 3.0 to 3.9 dl / g.

[0054] In some embodiments of the present disclosure, the polyolefin composition comprises 20-30 wt.% of component (A) and 70-80 wt.% of component (B), the amounts of (A) and (B) being based on the total weight of the polyolefin composition, the total weight being 100.

[0055] In preferred embodiments of the present disclosure, the polyolefin composition comprises:

[0056] (A) 18-35 wt.%, preferably 20-30 wt.% of a copolymer of propylene with ethylene

[0057] i) comprises 2.0-4.0 wt.%, preferably 3.0-3.9 wt.% of ethylene, the amount of ethylene being based on the weight of (A); and

[0058] ii) has a melt flow rate (MFR) measured according to ISO 1133, 230°C, 2.16 kg in the range of 30-60 g / 10 min, preferably 35-50 g / 10 min, more preferably 40-50 g / 10 min, still more preferably 42-48 g / 10 min; A ; and

[0059] (B) 65-82 wt.%, preferably 70-80 wt.% of a copolymer of propylene with ethylene, which comprises 20-35 wt.% of ethylene, the amount of ethylene being based on the weight of (B),

[0060] wherein

[0061] iii) the polyolefin composition comprises a fraction soluble in xylene at 25°C (XS(tot)) in an amount higher than 70 wt.%, preferably 70 to 90 wt.%, preferably 70 to 80 wt.%; and

[0062] iv) the amounts of (A), (B) and the fraction soluble in xylene at 25°C (XS(tot)) are based on the total weight of the polyolefin composition, the total weight being 100; and

[0063] v) the polyolefin composition has a melt flow rate (MFR) measured according to ISO 1133, 230°C, 2.16 kg in the range of 0.2 to 2.0 g / 10 min., preferably 0.3 to 1.5 g / 10 min., more preferably 0.4 to 1.0 g / 10 min., the melt flow rate being preferably obtained directly from polymerization; and

[0064] vi) the fraction soluble in xylene at 25°C (XS(tot)) of the polyolefin composition has an intrinsic viscosity (XS(IV)) in the range of 2.5-4.5 dl / g, preferably 3.0-3.9 dl / g.

[0065] In some embodiments of the present disclosure, the polyolefin composition has at least one of the following properties:

[0066] - a flexural modulus of -40 to 90 MPa, preferably 50 to 80 MPa, more preferably 50 to 70 MPa, wherein the flexural modulus is measured on injection molded test specimens according to ISO 178:2019; and / or

[0067] - a breaking strength of greater than or equal to 10.0 MPa, preferably greater than or equal to 11.0 MPa, measured on injection molded test specimens according to method ISO 527. In one embodiment, the breaking strength is 10 to 15 MPa, preferably 11 to 15 MPa; and / or

[0068] - a Charpy resistance at -40°C equal to or higher than 6.0 KJ / m 2 , measured on injection molded test specimens according to ISO 179 / 1 eA 2010. In one embodiment, the Charpy resistance at -40°C is comprised in the range of 6.0 to 10.0 KJ / m 2 ; and / or

[0069] - a puncture resistance of greater than or equal to 170 N, preferably greater than or equal to 200 N, measured on 1 mm thick extruded sheets according to method ASTM D 4833 (punch diameter: 8 mm, crosshead speed: 300 mm / min). In one embodiment, the puncture resistance is 170 to 250 N, preferably 200 to 250 N; and / or

[0070] - a puncture deformation of greater than or equal to 40 mm, preferably greater than or equal to 45 mm, measured on 1 mm thick extruded sheets according to method ASTM D 4833 (punch diameter: 8 mm, crosshead speed: 300 mm / min). In one embodiment, the puncture deformation is comprised in the range of 40 to 60 mm, preferably 45 to 60 mm; and / or

[0071] - a Shore D value equal to or lower than 30, measured on 1 mm thick extruded sheets according to method ISO 868 (15 seconds). In one embodiment, the Shore D value is comprised in the range of 23 to 30.

[0072] In preferred embodiments of the present disclosure, the polyolefin composition has a flexural modulus, a breaking strength, a Charpy resistance at -40°C, a puncture resistance, a puncture deformation and a Shore D value comprised in the ranges described above.

[0073] In some embodiments, the polyolefin composition is further endowed with at least one of the following properties measured on injection molded test specimens:

[0074] - an elongation at break determined according to method ISO 527 comprised in the range of 400-600%; and / or

[0075] - a Vicat softening temperature determined according to method ISO 306 (A50) comprised in the range of 40-60 °C; and / or

[0076] - a Shore A value determined according to method ISO 868 (15 seconds) comprised in the range of 70-90.

[0077] In some embodiments, the polyolefin composition is further endowed with at least one of the following properties measured on a 1 mm thick extruded sheet:

[0078] - a tensile modulus in MD and / or TD, preferably in MD and TD, determined according to method ISO 527-3 (specimen type 2, crosshead speed: 1 mm / min) comprised in the range of 30-70 MPa; and / or

[0079] - a breaking strength in MD and / or TD, preferably in MD and TD, determined according to method ISO 527-3 (specimen type: 5, crosshead speed: 500 mm / min) comprised in the range of 10.0-20.0 MPa, preferably 13.0-18.0 MPa;

[0080] - an elongation at break in MD and / or TD, preferably in MD and TD, determined according to method ISO 527-3 (specimen type: 5, crosshead speed: 500 mm / min) comprised in the range of 600-800%; and / or

[0081] - a tear resistance in MD and / or TD, preferably in MD and TD, determined according to method ASTM D 1004 (crosshead speed: 51 mm / min; V-shaped die cut specimen) comprised in the range of 40-70 g, preferably 40-60 g; and / or

[0082] - a Shore A value determined according to method ISO 868 (15 seconds) comprised in the range of 70-90.

[0083] In one embodiment, the polyolefin composition has all the properties described above.

[0084] The above disclosed properties are measured on injection molded and extruded specimens obtained as described in the experimental section of the present disclosure.

[0085] In some embodiments, the polyolefin composition is prepared by mixing the previously prepared components (A) and (B) in the molten state (e.g. in an extruder).

[0086] 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 and the catalyst used in the immediately preceding polymerization stage, the monomers and catalyst being fed in the first polymerization stage.

[0087] In some embodiments, the polymerization process to prepare the single components (A) and (B) or the sequential polymerization process to prepare the polyolefin composition is carried out in the presence of a catalyst selected from the group consisting of metallocene compounds, highly stereospecific Ziegler-Natta catalyst systems, and combinations thereof.

[0088] In some preferred embodiments, the polymerization process to prepare the single components (A) and (B) or the sequential polymerization process to prepare the polyolefin composition is carried out in the presence of a highly stereospecific Ziegler-Natta catalyst system comprising:

[0089] (1) a solid catalyst component comprising a magnesium halide support and a stereoregulating internal donor, on which there is a Ti compound having at least one Ti-halogen bond;

[0090] (2) optionally, but preferably, an aluminum-containing cocatalyst; and

[0091] (3) optionally, but preferably, an additional electron donor compound (external donor).

[0092] In some preferred embodiments, the solid catalyst component (1) comprises a titanium compound of formula Ti(OR) n X y_n wherein n is comprised between 0 and y; y is the atomic valence of titanium; X is a halogen, R is a hydrocarbon group having 1-10 carbon atoms or a -COR group. Among these, particularly preferred are titanium compounds having at least one Ti-halogen bond, such as titanium tetrahalides or titanium halogenated alcoholates. Preferred specific titanium compounds are TiCl3, TiCl4, Ti(OBu)4, Ti(OBu)Cl3, Ti(OBu)2Cl2, Ti(OBu)3Cl. TiCl4 is particularly preferred.

[0093] In one embodiment, the solid catalyst component (1) comprises a titanium compound in an amount ensuring the presence of 0.5-10 wt.% Ti with respect to the total weight of the solid catalyst component (1).

[0094] The solid catalyst component (1) comprises at least one stereoregulating internal electron donor compound selected from the group consisting of mono- or bidentate organic Lewis bases, preferably selected from the group consisting of esters, ketones, amines, amides, urethanes, carbonates, ethers, nitriles, alkoxysilanes, and combinations thereof.

[0095] Particularly preferred are electron donors which are esters of aliphatic or aromatic mono- or di-carboxylic acids and diethers.

[0096] Among the alkyl and aryl esters of optionally substituted aromatic polycarboxylic acids, preferred donors are esters of phthalic acid, such as those described in EP 45977 A2 and EP 395083 A2.

[0097] In some embodiments, the internal electron donor is selected from mono- or di- substituted phthalate esters, wherein the substituents are independently selected from linear or branched C 1-10 alkyl, C 3-8 cycloalkyl and aryl.

[0098] 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.

[0099] In one embodiment, the internal electron donor is diisobutyl phthalate.

[0100] Esters of aliphatic acids can be selected from malonic acids such as those described in WO 98 / 056830, WO 98 / 056833, WO 98 / 056834, glutaric acids such as those disclosed in WO 00 / 55215, and succinic acids such as those disclosed in WO 00 / 63261.

[0101] A particular type of diester is that derived from esterification of aliphatic or aromatic diols, such as those described in WO 2010 / 078494 and USP 7,388,061.

[0102] In some embodiments, the internal electron donor is selected from 1,3-diethers of the formula

[0103]

[0104] 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 1-4alkyl; or the carbon atom in position 2 of the 1,3-dioxetane belongs to a cyclic or polycyclic structure consisting 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, said structure containing two or three unsaturations (cyclopolyene structure) and optionally condensed with other cyclic structures, or substituted by one or more substituents selected from linear or branched alkyl; cycloalkyl, aryl, aralkyl, alkaryl and halogen, or fused with other cyclic structures and substituted by one or more of the above mentioned substituents, which can also be bound to the fused cyclic structure, wherein one or more of the above mentioned alkyl, cycloalkyl, aryl, aralkyl or alkaryl and fused cyclic structure optionally contain one or more heteroatoms as substituents of carbon and / or hydrogen atoms. This type of ether is described in EP 361493, EP 728769 and WO 02 / 100904.

[0105] When using the above 1,3-dioxetanes, no external electron donor (3) can be present.

[0106] In some cases, specific mixtures between internal donors, in particular aliphatic or aromatic mono- or di-carboxylates and 1,3-dioxetanes as disclosed in WO 07 / 57160 and WO 2011 / 061134 can be used as internal donor.

[0107] The preferred magnesium halide support is a magnesium dihalide.

[0108] In one embodiment, the amount of internal electron donor immobilized on the solid catalyst component (1) relative to the magnesium dihalide is from 5 to 20 mol%.

[0109] The preferred method for preparing the solid catalyst component starts from a magnesium dihalide precursor which, upon reaction with titanium chloride, transforms the precursor into the magnesium dihalide support. The reaction is preferably carried out in the presence of a steric regulating internal donor.

[0110] In a preferred embodiment, the magnesium dihalide precursor is a Lewis adduct of formula MgCl2-nR1OH, wherein n is a number from 0.1 to 6 and R1 is a hydrocarbon group having from 1 to 18 carbon atoms. Preferably n is from 1 to 5, more preferably from 1.5 to 4.5.

[0111] The adduct can be suitably prepared by mixing the alcohol and magnesium chloride, operating under stirring conditions at the melting temperature of the adduct (100-130°C).

[0112] The adduct is then mixed with an inert hydrocarbon immiscible with the adduct, thus creating an emulsion which is rapidly quenched, causing the solidification of the adduct in the form of spherical particles.

[0113] The thus obtained adduct can be reacted directly with the Ti compound or it can be subjected to a controlled dealcoholation (80-130°C) beforehand to obtain an adduct in which the number of moles of alcohol is generally lower than 3, preferably 0.1-2.5. This controlled dealcoholation step can be carried out to increase the morphological stability of the catalyst during polymerization and / or to increase the catalyst porosity, as described in EP 395083 A2.

[0114] The reaction with the Ti compound can be carried out by suspending the optionally dealcoholated adduct in cold TiCI4, generally at 0°C. The mixture is heated to 80-130°C and maintained at this temperature for 0.5-2 hours. The treatment with TiCI4can be carried out once or more than once. The stereoregulated internal donor can be added during the treatment with TiCI4. The treatment with the internal donor can be repeated once or more than once.

[0115] The preparation of the catalyst component according to this general process is described, for example, in European Patent Applications US 4,399,054, US 4,469,648, WO 98 / 44009 Al and, as already mentioned, EP 395083 A2.

[0116] In one embodiment, the catalyst component (1) is in the form of spherical particles having an average diameter of 10-350 μm, 20-250 μm 2 / g, preferably 80-200 m 2 / g, preferably 80-200 m

[0117] In some preferred embodiments, the catalyst system comprises an Al-containing cocatalyst (2) selected from Al-trialkyl, preferably selected from Al-triethyl, Al-triisobutyl and Al-tri-n-butyl.

[0118] In one embodiment, the Al / Ti weight ratio in the catalyst system is 1-1000, preferably 20-800.

[0119] In preferred embodiments, the catalyst system comprises a further electron donor compound (3) (external electron donor) selected from silicon compounds, ethers, esters, amines, heterocyclic compounds (in particular 2,2,6,6-tetramethylpiperidine) and ketones.

[0120] Preferably, the external donor is a silicon compound selected from the group consisting of formula (R2)a(R3)bSi(OR4)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; R2, R3 and R4 are alkyl, cycloalkyl or aryl groups having 1-18 carbon atoms, optionally containing heteroatoms. Particularly preferred are silicon compounds wherein 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, in particular methyl.

[0121] Examples of such preferred silicon compounds are selected from the group consisting of methylcyclohexyldimethoxysilane (C-donor), diphenyldimethoxysilane, methyl-tert- butyldimethoxysilane, dicyclopentyldimethoxysilane (D-donor), diisopropyldimethoxysilane, (2-ethylpiperidyl)tert-butyldimethoxysilane, (2-ethylpiperidyl)tert- hexyldimethoxysilane, (3,3,3-trifluoro-n-propyl)(2-ethylpiperidyl)dimethoxysilane, methyl(3,3,3-trifluoro-n-propyl)dimethoxysilane and combinations thereof.

[0122] Also preferred are silicon compounds wherein a is 0, c is 3, R3 is a branched alkyl or cycloalkyl group, optionally containing heteroatoms, and R4 is methyl. Examples of such silicon compounds are cyclohexyltrimethoxysilane, tert-butytrimethoxysilane and hexyltrimethoxysilane.

[0123] Even though several combinations of components of the catalyst system allow to obtain the polyolefin composition of the present disclosure, a particularly suitable catalyst system comprises diisobutyl phthalate as internal electron donor and dicyclopentyldimethoxysilane (D-donor) as external electron donor (3).

[0124] In one embodiment, the catalyst system is precontacted (prepolymerized) with a small amount of olefin, maintained in suspension in a hydrocarbon solvent and polymerized at a temperature of from 25°C to 60°C, yielding an amount of polymer from about 0.5 to about 3 times the weight of the catalyst system.

[0125] In an alternative embodiment, the prepolymerization is carried out in liquid monomer, yielding an amount of polymer 1000 times the weight of the catalyst system.

[0126] The sequential polymerization process for the preparation of the polyolefin composition of the present disclosure is described in EP 472946 and WO 03 / 011962, the contents of which are incorporated in the present patent application for reference purposes.

[0127] Components (A) and (B) can be prepared in any one of the polymerization stages.

[0128] In one embodiment, the polymerization process comprises a polymerization stage carried out in the presence of a highly stereospecific Ziegler-Natta catalyst system, wherein:

[0129] (a) in a first copolymerization stage, monomers are polymerized to form a propylene copolymer (A); and

[0130] (b) in a second copolymerization stage, relevant monomers are polymerized to form a propylene copolymer (B).

[0131] In one embodiment, the second copolymerization stage (b) comprises a copolymerization stage (bl) and a copolymerization stage (b2), wherein comonomers are polymerized to form a propylene copolymer (Bl) in stage (bl) and a copolymer (B2) in stage (b2).

[0132] In one embodiment, the second copolymerization stage (b) comprises a copolymerization stage (bl) and a copolymerization stage (b2), wherein a propylene copolymer (B2) is formed in copolymerization stage (bl) and a propylene copolymer (Bl) is formed in polymerization stage (b2).

[0133] The polymerization, which can be continuous or batch, can be operated in mixed liquid / gas phase or completely in gas phase according to known cascade techniques.

[0134] The liquid phase polymerization can be slurry, solution or bulk (liquid monomer). The latter technique is the most preferred and can be carried out in various types of reactors such as continuous stirred tank reactors, loop reactors or plug flow reactors.

[0135] The gas phase polymerization stage can be carried out in a gas phase reactor, for example a fluidized bed or a stirred fixed bed reactor.

[0136] In one embodiment, copolymerization stage (a) is carried out in liquid phase using liquid propylene as diluent and copolymerization stage (b) or copolymerization stages (bl) and (b2) are carried out in gas phase.

[0137] In a preferred embodiment, copolymerization step (a) is also carried out in gas phase.

[0138] In one embodiment, the reaction temperature of polymerization stages (a), (b), (bl) and (b2) is independently selected from values comprised in the range from 40°C to 90°C.

[0139] In one embodiment, the polymerization pressure of copolymerization stage (a) carried out in liquid phase is from 3.3 to 4.3 MPa.

[0140] In one embodiment, the polymerization pressure of copolymerization stages (a), (b), (bl) and (b2) carried out in gas phase is independently selected from values from 0.5 to 3.0 MPa.

[0141] 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. In one embodiment, the residence time in each polymerization stage is from 15 minutes to 8 hours.

[0142] When the polyolefin composition of the present disclosure is prepared by a continuous polymerization process, the amounts of components (A) and (B) or components (A), (B1) and (B2) correspond to the split between the polymerization reactors.

[0143] The molecular weight of the propylene copolymer obtained in the polymerization stage is adjusted using a chain transfer agent such as hydrogen or ZnEt2.

[0144] In some preferred embodiments of the present disclosure, the polyolefin composition is blended with additives at the end of the polymerization reaction.

[0145] In one embodiment, the polyolefin composition is an additive-containing polyolefin composition (AD1) comprising up to and including 0.3 wt.%, preferably 0.01-0.3 wt.% of at least one first additive (C) selected from the group consisting of antistatic agents, antioxidants, acid scavengers, melt stabilizers and combinations thereof, of the type used in the polyolefin art, relative to the total amount of the additive-containing polyolefin composition (AD1).

[0146] In one embodiment, the polyolefin composition is an additive-containing polyolefin composition (AD1) consisting of component (A), component (B) and at least one first additive (C), the total weight of the additive-containing polyolefin composition (AD1) being 100, relative to the total amount of the additive-containing polyolefin composition (AD1), the total amount of the additive-containing polyolefin composition (AD1) preferably being up to and including 0.3 wt.%, more preferably 0.01 to 0.3 wt.%.

[0147] In some embodiments, the polyolefin composition further comprises at least one second additive (D) selected from the group consisting of fillers, pigments, nucleating agents, extender oils, flame retardants (e.g. aluminum trihydrate), anti-UV agents (e.g. titanium dioxide), UV stabilizers, lubricants (e.g. oleamide), antiblocking agents, waxes, coupling agents for fillers and combinations thereof, the second additive (D) being of the type used in the polymer compounding art.

[0148] In one embodiment, the additive-containing polyolefin composition comprises up to and including 50 wt.%, preferably 0.01-50 wt.%, more preferably 0.5-30 wt.% of at least one second additive (D), the amount of at least one second additive (D) being based on the total weight of the polyolefin composition including additive (D), the total weight being 100.

[0149] In some embodiments, the polyolefin composition is an additive-containing polyolefin composition (AD2) comprising component (A) and component (B) as described above, and

[0150] (C) at most and including 0.3 wt.%, preferably 0.01 - 0.3 wt.% of at least one first additive; and

[0151] (D) at most and including 50 wt.%, preferably 0.01 - 50 wt.%, more preferably 0.5 - 30 wt.% of at least one second additive,

[0152] 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), which is 100.

[0153] In one embodiment, the first additive (C) and the second additive (D) are selected from the group described above.

[0154] In one embodiment, the additive-containing polyolefin composition (AD2) consists of components (A), (B), (C) and (D).

[0155] Another object of the present disclosure is a sheet or film comprising the polyolefin composition of the present disclosure.

[0156] In one embodiment, the sheet or film comprises the additive-containing polyolefin (AD1) or the additive-containing polyolefin composition (AD2).

[0157] In some embodiments, the sheet or film has a total thickness of 1000 - 2000 pm, preferably 1200 - 1800 pm.

[0158] The sheet or film is a single-layer or a multi-layer sheet or film.

[0159] In one embodiment, the sheet or film is a single-layer sheet or film comprising the polyolefin composition or the additive-containing polyolefin composition (AD1) or the additive-containing polyolefin composition (AD2).

[0160] In one embodiment, the single-layer sheet or film consists of the polyolefin composition or the additive-containing polyolefin composition (AD1) or the additive-containing polyolefin composition (AD2).

[0161] In some embodiments, the sheet or film is a multi-layer sheet or film comprising at least one layer X, wherein layer X comprises the polyolefin composition or the additive-containing polyolefin composition (AD1) or the additive-containing polyolefin composition (AD2).

[0162] In one embodiment, layer X comprised in the multi-layer sheet or film consists of a polyolefin composition or an additive-containing polyolefin composition (AD1) or an additive- containing polyolefin composition (AD2).

[0163] In one embodiment, the multi-layer sheet or film comprises layer X and layer Y, wherein layer X and layer Y comprise a polyolefin independently selected from the group consisting of a polyolefin composition, an additive-containing polyolefin composition (AD1) and an additive- containing polyolefin composition (AD2).

[0164] 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, an additive-containing polyolefin composition (AD1) and an additive- containing polyolefin composition (AD2).

[0165] In one embodiment, the multi-layer sheet or film consists of layer X and layer Y, wherein layer X and layer Y comprise a polyolefin independently selected from the group consisting of a polyolefin composition, an additive-containing polyolefin composition (AD1) and an additive- containing polyolefin composition (AD2).

[0166] In one embodiment, the multi-layer sheet or film consists of 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, an additive-containing polyolefin composition (AD1) and an additive- containing polyolefin composition (AD2).

[0167] In one embodiment, the multi-layer 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 comprising a plastic material selected from the group consisting of a propylene homopolymer, a propylene copolymer, a polyethylene, a polyethylene terephthalate and combinations thereof.

[0168] In one embodiment, layer Z is a woven fabric or a non-woven fabric.

[0169] 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.

[0170] The multi-layer sheet or film can be obtained by co-extrusion of the polyolefins comprised in the layers or by lamination of the layers.

[0171] In one embodiment, the sheet or film is a single-layer roofing sheet or film.

[0172] In one embodiment, the sheet or film is a geomembrane.

[0173] The features of the disclosed subject matter described herein are not mutually exclusive, and can exist alone or in any conceivable combination. Thus, the specific level of preference for one feature is not necessarily dependent on the same level of preference for the remaining features. Moreover, it is intended to be within the scope of the disclosure that any combination of parameters and / or features, even if not explicitly described, forms part of the disclosure.

[0174] Embodiments

[0175] The following examples are merely illustrative and are not intended to limit the scope of the disclosure in any way.

[0176] Characterization methods

[0177] The following methods were used to determine the properties indicated in the specification, claims and examples.

[0178] Melt flow rate: determined according to method ISO 1133 (230 °C, 2.16 kg).

[0179] Solubility in xylene at 25 °C: 2.5 g of 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 reduced to 100 °C under 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 reduced to 25 °C without stirring during the first 20 minutes and was kept at 25 °C with stirring during the last 10 minutes. The solid formed was filtered on 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, heated to 140 °C on a hot plate under a stream of nitrogen to remove the solvent by evaporation. The container was then kept under vacuum in an oven at 80 °C until a constant weight was reached. The amount of polymer soluble in xylene at 25 °C was then calculated. XS(tot) and XS A The values were determined experimentally. The fraction of component (B) soluble in xylene at 25 °C (XS B ) can be calculated from:

[0180] XS = W(A) x (XS A ) + W(B) x (XS B )

[0181] where W(A) and W(B) are the relative amounts of components (A) and (B), respectively, and W(A) + W(B) = 1.

[0182] Intrinsic viscosity of the xylene-soluble fraction: To calculate the intrinsic viscosity IV, the flow time of the polymer solution is compared to the flow time (THN) of the solvent. A Ubbelohde glass capillary viscometer is used. The oven temperature is adjusted to 135°C. The temperature must be stable (135° ± 0.2°C) before starting to measure the solvent flow time t0. The sample meniscus is detected by a photoelectric device.

[0183] Sample preparation: Pour 100 ml of filtrate (S1) into a beaker and add 200 ml of acetone while stirring vigorously. Precipitation of the insoluble fraction must be complete, as confirmed by a clear solid-solution separation. Filter the suspension through a weighing 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 constant weight is achieved. Weigh 0.05 g of the precipitate and dissolve it in 50 ml of tetrahydronaphthalene (THN) at 135 °C. Measure the discharge time t of the sample solution and convert it to an intrinsic viscosity value [η] using the Huggins equation (Huggins, ML, *Journal of the American Chemical Society* (J. Am. Chem. Soc.) 1942, 64, 11, 2716–2718) and the following data:

[0184] - The concentration of the sample (g / dl);

[0185] - The density of the solvent at 135°C;

[0186] - The flow time t0 of the solvent at 135°C on the same viscometer.

[0187] [η] is determined using a single polymer solution.

[0188] Comonomer content: 13 C10 NMR spectra were obtained on a Bruker Av-600 spectrometer equipped with a cryoprobe, operated at 160.91 MHz in Fourier transform mode at 120 °C. S0 was detected at 29.9 ppm. δδ Carbon peaks (according to "through") 13 Monomer sequence distribution in ethylene-propylene rubber measured by C10 NMR. 3. Use of reaction probability mode, “Nomenclature of CJ Carman, RA Harrington and CE Wilkes, Macromolecules, 1977, 10, 536”, is used as an internal reference.

[0189] The sample was dissolved in 1,1,2,2-tetrachloroethane-d2 at 120 °C with a concentration of 8 wt / v%. A 90° pulse was applied, with a 15-second delay between the pulse and the CPD to remove [the sample].1 H- 13 C coupling. A spectral window of 9000 Hz was used to store 512 transients in 32K data points. Spectral assignment, triplet distribution, evaluation of composition were made 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, 1150) using the following equations:

[0190] PPP = 100T ββ PPE = 100T βδ EPE = 100T δδ /

[0191] PEP = 100S ββ PEE = 100S βδ EEE = 100(0.25S γδ + 0.5S δδ )

[0192] S = T ββ + T βδ + T δδ + S ββ + S βδ + 0.25S γδ + 0.5S δδ

[0193] The molar content of ethylene and propylene was calculated from triads using the following equations:

[0194] [E]mol = EEE + PEE + PEP

[0195] [P]mol = PPP + PPE + EPE

[0196] The weight percent of ethylene content (E wt%) was calculated using the following equation:

[0197]

[0198] where

[0199] [P]mol = molar percentage of propylene content;

[0200] MWE = Molecular weight of ethylene

[0201] MWP = Molecular weight of propylene.

[0202] According to Carman (CJ Carman, R.A. Harrington, and C.E. Wilkes, *Macromolecules*, 1977; 10, 536), the product of the reaction ratios r1 and r2 is calculated as follows:

[0203]

[0204] The stereoregularity of the propylene sequence is determined by PPP mmT ββ (28.90-29.65ppm) and the entire T ββ The ratio of (29.80-28.37ppm) is calculated as mm content.

[0205] The ethylene content of component B) is calculated from the total ethylene content of the polymer (C2(tot)) using the following formula:

[0206] C2(tot)=W(A)×C2(A)+W(B)×C2(B)

[0207] Where W(A) and W(B) are the relative amounts of components (A) and (B) (W(A) + W(B) = 1), and C2(A) and C2(B) are the weight percentages of ethylene in components (A) and (B).

[0208] Injection molded specimens: 80×10×4mm specimens were obtained according to method ISO 1873-2:2007.

[0209] Flexural modulus: determined on injection-molded specimens according to method ISO 178:2019.

[0210] Breaking strength and elongation at break: determined on injection-molded specimens according to method ISO 527.

[0211] Shore A and D on injection molded specimens: determined according to method ISO 868 (15 seconds).

[0212] Vicat softening temperature: determined on injection-molded specimens according to method ISO 306 (A50).

[0213] Charpy impact test at -40°C: Measured on injection-molded specimens according to ISO 179 / 1eA 2010.

[0214] Tensile modulus (MD and TD): determined on 1 mm thick extruded sheets according to method ISO 527-3. Test specimen type 2, crosshead speed: 1 mm / min.

[0215] Tensile strength and elongation at break (MD and TD): determined on 1 mm thick extruded sheets according to method ISO 527-3. Test specimen type: 5, crosshead speed: 500 mm / min.

[0216] Tear resistance: determined on 1 mm thick extruded sheets according to method ASTM D 1004. Crosshead speed: 51 mm / min; V-shaped die cut test specimen.

[0217] Puncture resistance and deformation: determined on 1 mm thick extruded sheets according to method ASTM D 4833. Punch diameter 8 mm, crosshead speed: 300 mm / min.

[0218] Shore A and D on extruded sheets: determined on 1 mm thick extruded sheets according to method ISO 868 (15 seconds).

[0219] Preparation of extruded test specimens: the polymer in the form of granules was fed via a feed hopper into a Leonard extruder (single screw extruder, diameter 40 mm and length 27 L / D), where the polymer was first melted (melt temperature 230 °C), compressed, mixed and finally metered out with a metering pump (15 cc / rpm) at a throughput rate of 10 kg / h. The molten polymer left the flat die (width 200 mm, die lip 0.8-0.9 mm) and was immediately cooled by a vertical three-roll calender with a roller temperature of 60 °C. An extruded sheet of 1 mm thickness was obtained.

[0220] Example 1 and Comparative Example 2

[0221] The polymerization was 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.

[0222] For the polymerization, a Ziegler-Natta catalyst system was used, which comprises:

[0223] - a titanium-containing solid catalyst component prepared with the procedure described in EP 395083 Example 3, according to which diisobutyl phthalate was used as internal electron donor compound;

[0224] - triethylaluminium (TEAL) as co-catalyst;

[0225] - dicyclopentyl dimethoxysilane (DCPMS) as external electron donor.

[0226] The solid catalyst component is contacted with TEAL and DCPMS in a pre-contacting vessel, the weight ratio of TEAL to the solid catalyst component being 4-5, the weight ratio of TEAL / DCPMS being 5.

[0227] The catalyst system is then prepolymerized by keeping it in liquid propylene suspension at 20°C for about 30-32 minutes, after which it is introduced into the first polymerization reactor.

[0228] The propylene copolymer (A) is prepared by feeding the prepolymerized catalyst system, hydrogen (used as molecular weight regulator), propylene and ethylene, all in gaseous phase, in a continuous and constant flow into the first gas phase reactor.

[0229] The propylene copolymer (A) from the first reactor is discharged in a continuous flow and, after having eliminated the unreacted monomers, is introduced into the second gas phase reactor in a continuous flow together with a constant and metered flow of hydrogen and ethylene, both in gaseous state.

[0230] The propylene copolymer (B) is prepared in the second reactor.

[0231] The polymerization conditions, the molar ratios of the reactants and the composition of the copolymers obtained are shown in Table 1.

[0232] Table 1 - Polymerization conditions

[0233]

[0234] Notes: C2- = ethylene in gas phase (IR); C3- = propylene in gas phase (IR); split = amount of polymer produced in the relevant reactor. (*) Calculated value.

[0235] The polymer particles leaving the second reactor are subjected to steam treatment to remove unreacted monomers and volatile compounds and then dried.

[0236] The polyolefin composition thus obtained is mixed with the additives in a twin-screw extruder Berstorff ZE 25 (length / diameter ratio of the screws: 34) and extruded under a nitrogen atmosphere under the following conditions:

[0237] Rotation speed: 250 rpm;

[0238] Extruder output: 15 kg / h;

[0239] Melt temperature: 245°C.

[0240] The additives added to the polyolefin composition are:

[0241] - 0.1 wt.% of 1010;

[0242] - 0.1 wt. % of 168;

[0243] - 0.05 wt. % of

[0244] The amount of additive is based on the total weight of the polyolefin composition containing the additive.

[0245] 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- hydroxyphenyl-propanoate; 168 is tris(2,4-di-tert-butylphenyl) phosphite; is aluminum magnesium carbonate hydroxide (hydrate).

[0246] The properties of the materials tested on injection molded test specimens are reported in Table 3. The properties of the materials tested on extruded sheet are reported in Table 4.

[0247] Example 3 and Comparative Example 4

[0248] The polyolefin composition was prepared in three gas phase reactors connected in series and equipped with means to transfer the product from one reactor to the subsequent reactor, using the same catalyst system as in Example 1.

[0249] The propylene copolymer (A) was prepared by feeding the prepolymerized catalyst system, hydrogen (used as molecular weight regulator), propylene and ethylene, all in gas phase, in a continuous and constant flow into a first gas phase reactor.

[0250] The propylene copolymer (A) from the first reactor was discharged in a continuous flow and, after having removed the unreacted monomers, was introduced in a continuous flow into a second gas phase reactor together with a constant and metered flow of hydrogen and ethylene, both in gaseous state.

[0251] The propylene copolymer (B1) was prepared in the second reactor. The product from the second reactor was discharged in a continuous flow and, after having removed the unreacted monomers, was introduced in a continuous flow into a third gas phase reactor together with a constant and metered flow of hydrogen, ethylene and propylene, all in gaseous state. The ethylene-propylene polymer (B2) was prepared in the third reactor.

[0252] The polymerization conditions, the molar ratio of the reactants and the composition of the copolymers obtained are shown in Table 2.

[0253] Table 2 - Polymerization conditions

[0254]

[0255] Note: C2- = ethylene in gas phase (IR); C3- = propylene in gas phase (IR); Split = amount of polymer produced in the associated reactor. (*) Calculated.

[0256] The polymer particles exiting the third reactor were steam treated to remove unreacted monomers and volatile compounds, dried and melt mixed with additives as described in Example 1.

[0257] The properties of the materials tested on injection molded specimens are reported in Table 3. The properties of the materials tested on extruded sheets are reported in Table 4.

[0258] Table 3 - Characterization of injection molded specimens

[0259] Example 1 Comparative Example 2 Example 3 Comparative Example 4 MFR g / 10 min 0.51 0.61 0.40 0.65(**) Flexural modulus MPa 56 99 50 46 Breaking strength MPa 11.5 10.5 12.4 9.9 Breaking elongation ％ 440 400 510 505 Vicat temperature (9.81 N) ℃ 51 62 48 46 Charpy resistance -40°C KJ / m 2 ]]> 6.1 5.2 6.5 5.2 Shore A 86 >90 84 79 Shore D 25 31 25 <20

[0260] (**) The polyolefin was cracked with 170 ppm of peroxide to increase the MFR and make it processable using state of the art extruders used to produce sheets or films.

[0261] Table 4 - Characterization of extruded sheets

[0262] Example 1 Comparative Example 2 Example 3 Comparative Example 4 MFR g / 10 min 0.51 0.61 0.40 0.65(**) Tensile modulus MD MPa 44 74 66 46 Breaking strength MD MPa 16.0 20.0 14.9 12.2 Breaking elongation MD ％ 730 760 660 690 Tensile modulus TD MPa 41 71 40 32 Breaking strength TD MPa 14.5 20.2 14.0 12.1 Breaking elongation TD ％ 730 820 680 711 Tear resistance MD g 49 70 58 50 Tear resistance TD g 54 70 58 46 Puncture resistance N 186 241 210 165 Puncture deformation mm 51 48 51 48 Shore A 83 >90 84 80 Shore D 25 34 23 24

[0263] (**) The polyolefin was cracked with 170 ppm of peroxide to increase the MFR and make it processable using state of the art extruders used to produce sheets or films.

Claims

1. A polyolefin composition comprising: (A) 18-35 wt.% copolymer of propylene with at least one α-olefin of the formula CH2=CHR, wherein R is H or a straight-chain or branched C2-C3 alkyl group, wherein i) The copolymer contains 2.0-4.0 wt.% of at least one α-olefin, the amount of which is based on the total weight of (A); as well as ii) The copolymer has a melt flow rate (MFR) in the range of 40 to 50 g / 10 min, as measured according to ISO 1133, 230 °C, 2.16 kg. A );as well as (B) A copolymer of 65-82 wt.% propylene with at least one α-olefin of the formula CH2=CHR and optionally a diene, wherein R is H or a straight-chain or branched C2-C8 alkyl group, and wherein said copolymer comprises 20-35 wt.% α-olefin, the amount of which is based on the total weight of (B). in iii) The polyolefin composition comprises more than 70 wt.% of a xylene-soluble fraction (XS(tot)) at 25°C. iv)(A), (B), and the amount of xylene soluble at 25°C (XS(tot)) are based on the total weight of the polyolefin composition; and v) The melt flow rate (MFR) of the polyolefin composition, measured according to ISO 1133, 230°C, 2.16 kg, is 0.2 to 2.0 g / 10 min.

2. The polyolefin composition according to claim 1, wherein the copolymer (A) is a copolymer of propylene and ethylene.

3. The polyolefin composition according to claim 1, wherein the copolymer (A) has a melt flow rate (MFR) of 42-48 g / 10 min as measured according to ISO 1133, 230°C, 2.16 kg. A ).

4. The polyolefin composition according to claim 1, wherein the copolymer (A) comprises a xylene-soluble fraction (XS) in the range of 4.0-9.0 wt.% based on the weight of the copolymer (A). A The amount of ).

5. The polyolefin composition according to claim 1, wherein component (B) comprises: (B1) 30-60 wt.% of a first copolymer of propylene with at least one α-olefin of the formula CH2=CHR and optionally a diene, wherein R is H or a straight-chain or branched C2-C8 alkyl group, and wherein said first copolymer comprises 20-40 wt.% of an α-olefin and more than 80 wt.% of a xylene-soluble fraction (XS) at 25°C. B1 ), α-olefins and XS B1 The amount is based on the weight of component (B1); as well as (B2) 40-70 wt.% of a second copolymer of propylene with at least one α-olefin of the formula CH2=CHR and optionally a diene, wherein R is H or a straight-chain or branched C2-C8 alkyl group, and wherein said second copolymer comprises 25-45 wt.% of an α-olefin and more than 80 wt.% of a xylene-soluble fraction (XS) at 25°C. B2 ), α-olefins and XS B2 The amount is based on the weight of component (B2). The amounts of (B1) and (B2) are based on the total weight of component (B).

6. The polyolefin composition according to claim 5, wherein the component (B) comprises 40-55 wt.% of component (B1) and 45-60 wt.% of component (B2).

7. The polyolefin composition according to claim 1, wherein the at least one α-olefin contained in components (B), (B1) and (B2) is independently selected from ethylene, butene-1, hexene-1, 4-methyl-pentene-1, octene-1 and combinations thereof.

8. The polyolefin composition according to claim 1, wherein the at least one α-olefin contained in components (B), (B1) and (B2) is ethylene.

9. The polyolefin composition according to claim 1, comprising 70 to 90 wt.% of a xylene-soluble fraction (XS(tot)) at 25°C, the amount of XS(tot) being based on the total weight of the polyolefin composition.

10. The polyolefin composition according to claim 1, having a melt flow rate of 0.4 to 1.0 g / 10 min as measured according to ISO 1133, 230°C, 2.16 kg.

11. The polyolefin composition according to claim 1, wherein the xylene-soluble portion of the polyolefin composition at 25°C has an intrinsic viscosity (XS(IV)) of 2.5 to 4.5 dl / g.

12. The polyolefin composition according to claim 1, wherein the xylene-soluble portion of the polyolefin composition at 25°C has an intrinsic viscosity (XS(IV)) of 3.0 to 3.9 dl / g.

13. The polyolefin composition according to claim 1, wherein: (A) 18-35 wt.% copolymer of propylene and ethylene, comprising 2.0-4.0 wt.% ethylene, the amount of ethylene being based on the weight of (A) and having a melt flow rate (MFR) of 40-50 g / 10 min as measured according to ISO 1133, 230°C, 2.16 kg. A );as well as (B) 65-82 wt.% of a copolymer of propylene and ethylene, comprising 20-35 wt.% ethylene, the amount of ethylene being based on the weight of (B). in iii) The polyolefin composition comprises more than 70 wt.% of a xylene-soluble fraction (XS(tot)) at 25°C; and iv)(A), (B), and the amount of xylene soluble at 25°C (XS(tot)) are based on the total weight of the polyolefin composition; and v) The melt flow rate (MFR) of the polyolefin composition, measured according to ISO 1133, 230°C, 2.16 kg, is in the range of 0.2 to 2.0 g / 10 min, said melt flow rate being obtained directly from polymerization; and vi) The xylene-soluble portion (XS(tot)) of the polyolefin composition at 25°C has an intrinsic viscosity (XS(IV)) of 2.5-4.5 dl / g.

14. The polyolefin composition according to claim 1, wherein it has at least one of the following properties: -40-90 MPa flexural modulus, wherein the flexural modulus is measured on injection-molded specimens according to ISO 178:2019; and / or - A breaking strength greater than or equal to 10.0 MPa, measured on an injection-molded specimen according to method ISO 527; and / or - Equal to or greater than 6.0 KJ / m 2 The Charpy resistivity at -40°C, measured on an injection-molded specimen according to ISO 179 / 1eA 2010; and / or - Puncture resistance greater than or equal to 170 N, measured according to method ASTM D 4833 on a 1 mm thick extruded sheet, punch diameter: 8 mm, crosshead speed: 300 mm / min; and / or - Puncture deformation greater than or equal to 40 mm, measured according to method ASTM D 4833 on a 1 mm thick extruded sheet, punch diameter: 8 mm, crosshead speed: 300 mm / min; and / or - A Shore D value equal to or less than 30, measured according to method ISO 868, 15 seconds, on a 1 mm thick extruded sheet.

15. A sheet or film comprising the polyolefin composition according to claim 1.

16. The sheet or film of claim 15, wherein the sheet or film is a multilayer sheet or film having a layer structure X / Z / Y, wherein layer X and layer Y comprise the polyolefin composition of claim 1, and layer Z is a reinforcing layer comprising a plastic material selected from propylene homopolymers, propylene copolymers, polyethylene, polyethylene terephthalate, and combinations thereof.

17. The sheet or film according to claim 15, wherein it is a single-layer sheet or film.

18. Use of the sheet or membrane according to claim 15, wherein it is used as a geomembrane.

Images