Patent Description:
Both elastomers and thermoplastic polyolefins are largely used in the art to produce sheets and membranes for single ply roofing.

Traditionally, polyvinyl chloride (PVC) and other chlorinated TPOs were used to prepare heat-weldable thermoplastic roofing sheets. However, PVC requires plasticizers to have the flexibility needed for roofing applications. The aging of membranes through plasticizers loss and the presence of chlorine in the polymer chains were the drivers for the substitution of PVC with chlorine-free thermoplastic polyolefins having the required mechanical properties in absence of plasticizers.

Heterophasic polyolefin compositions are used to prepare sheets or membranes for roofing applications, the compositions being heat-weldable, endowed with suitable mechanical properties and easily recyclable.

<CIT> discloses a polyolefin composition comprising: (I) a composition comprising (a) <NUM>-<NUM> wt% of a propylene homopolymer, or a copolymer of propylene with ethylene or a CH2=CHR alpha-olefin; and (b) <NUM>-<NUM> wt% of one or more copolymers selected from (b1) copolymers of ethylene, and (b2) copolymers of ethylene with propylene and the alpha-olefin; and (II) an additives package. The polyolefin composition is useful for producing a membrane for use as a geomembrane.

<CIT> discloses a polyolefin composition for roofing applications having good tenacity, the composition comprising: (A) <NUM>-<NUM> wt. % of a crystalline copolymer of propylene and (B) <NUM>-<NUM> wt. % of an elastomeric fraction comprising a copolymer of propylene with ethylene and a copolymer of ethylene with alpha-olefins.

<CIT> discloses a membrane comprising a base layer (A) and a top layer (B). The base layer (A) is made of a heterophasic composition comprising: (a) <NUM>-<NUM> wt. % of a propylene homo- or copolymer; and (b) <NUM>-<NUM> wt. % of one or more copolymers of ethylene with a C3-C10 alpha-olefin. The top layer (B) comprises a propylene polymer selected among propylene homopolymers, propylene copolymers with ethylene or a C4-C10 alpha-olefin and combinations thereof. The membrane has good tensile properties and good tear resistance.

Highly inert multilayer membranes having good tear and puncture resistance are disclosed in <CIT>. The membrane comprises: a base layer (A) and a top layer (B). The base layer (A) comprises: (a) <NUM>-<NUM> wt. % of a propylene homo- or copolymer and (b) <NUM>-<NUM> wt. % of one or more copolymers of ethylene with a C3-C10 alpha-olefin. The top layer (B) comprises an ethylene homopolymer or copolymer having density from <NUM> to <NUM>/cm<NUM>.

In this context, there is still the need of polyolefin compositions with an appropriate balance of physical and mechanical properties and good processability, which are particularly suited for preparing sheets or membranes retaining softness and having good puncture and tear resistance.

The present disclosure provides a polyolefin composition comprising:.

The present disclosure also provides a sheet or membrane comprising a polyolefin composition comprising:.

The polyolefin composition of the present disclosure shows a good balance of mechanical properties, in particular of flexibility and softness, at the same time retaining good elastic properties and toughness at low temperature.

The polyolefin composition is also endowed with high puncture and tear resistance.

The polyolefin composition has reduced stickiness and it is therefore easily processable into sheets or membranes, particularly into sheets or membranes suited for roofing applications.

The sheets or membranes comprising the polyolefin composition of the present disclosure are soft and flexible, easy to install, and have remarkable puncture and tear resistance.

While multiple embodiments are disclosed, still 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, are capable of modifications in various obvious aspects, all without departing from the spirit and scope of the claims as presented herein. Accordingly, the following detailed description is to be regarded as illustrative in nature and not restrictive.

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

In one embodiment, the component (A) is a propylene copolymer comprising <NUM>-<NUM>% by weight of the at least one alpha-olefin, preferably the propylene copolymer comprises <NUM>-<NUM>% by weight of ethylene.

In some embodiments, the propylene copolymer (A) has melt flow rate (MFRA), measured according to ISO <NUM>, <NUM>, <NUM>, ranging from <NUM> to <NUM>/<NUM>. , preferably from <NUM> to <NUM>/<NUM>. , more preferably from <NUM> to <NUM>/<NUM>.

In some embodiments, the propylene copolymer (A) comprises an amount of fraction soluble in xylene at <NUM> (XSa) lower than <NUM>% by weight, preferably the xylene soluble fraction XSA is comprised in the range <NUM>-<NUM>% by weight, more preferably <NUM>-<NUM>% by weight, the amount of XSA is based on the weight of copolymer (A).

In some embodiments, the propylene copolymer (B) comprises an amount of fraction soluble in xylene at <NUM> (XSB) higher than <NUM>% by weight, preferably higher than <NUM>% by weight, more preferably higher than <NUM>% by weight, the amount of XSB is based on the weight of copolymer (B).

In one embodiment, the upper limit of the amount of the fraction of component (B) soluble in xylene at <NUM> (XSB) is <NUM>% by weight for each lower limit, the amount of XSB is based on the weight of copolymer (B).

In some embodiments, the component (B) comprises a first copolymer (B1) and a second copolymer (B2) of propylene with at least one alpha-olefin of formula CH<NUM>=CHR, and optionally a diene, where R is H or a linear or branched C2-C8 alkyl, provided that the total amount of alpha-olefin comprised in the propylene copolymer (B) is <NUM>-<NUM>% by weight, the total amount of alpha-olefin is based on the weight of component (B).

In one embodiment, the component (B) comprises:.

wherein the amounts of (B1) and (B2) are based on the total weight of the component (B), the weight being <NUM>.

In one embodiment, the upper limit of the amount of the fraction of the component (B1) and/or of the component (B2) soluble in xylene at <NUM> (XSB1 and/or XSB2) is <NUM>% by weight for each lower limit, the amounts of XSB1 and XSB2 are based on the weight of component (B1) and (B2) respectively.

In one embodiment, the upper limit of XSB1 and of XSB2 is <NUM>% by weight for each lower limit, the amounts of XSB1 and XSB2 are based on the weight of component (B1) and (B2) respectively.

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-<NUM>, hexene-<NUM>, <NUM>-methy-pentene-<NUM>, octene-<NUM> and combinations thereof. In a preferred embodiment, the alpha-olefin is ethylene.

Optionally, the propylene copolymers (B) and/or (B1) and/or (B2) comprise recurring units derived from a diene, the diene being preferably independently selected from the group consisting of butadiene, <NUM>,<NUM>-hexadiene, <NUM>,<NUM>-hexadiene, ethylidene-<NUM>-norbonene and combinations thereof.

In some embodiments, the total amount of recurring units deriving from a diene comprised in the propylene copolymer (B), (B1) and/or (B2) ranges from <NUM> to <NUM>% by weight, with respect to the relevant component, the amount of recurring units deriving from a diene being based on the weight of the component (B).

In some embodiments of the present disclosure, the polyolefin composition comprises a total amount of fraction soluble in xylene (XS(tot)) at <NUM> ranging from <NUM> to <NUM>% by weight, preferably from <NUM> to <NUM>% by weight, the amount of XS(tot) is based on the total weight of the polyolefin composition.

In some embodiments of the present disclosure, the polyolefin composition has melt flow rate (MFR) measured according to ISO <NUM>, <NUM>, <NUM> ranging from <NUM> to <NUM>/<NUM>. , preferably from <NUM> to <NUM>/<NUM>.

In some embodiments of the present disclosure, the melt flow rate (MFR) of the polyolefin composition measured according to ISO <NUM>, <NUM>, <NUM> of from <NUM> to <NUM>/<NUM>. , preferably from <NUM> to <NUM>/<NUM>. , more preferably from <NUM> to <NUM>/<NUM>. , is obtained directly from polymerization.

In some embodiments of the present disclosure, the melt flow rate (MFR) of the polyolefin composition measured according to ISO <NUM>, <NUM>, <NUM> of from <NUM> to <NUM>/<NUM>. , preferably from <NUM> to <NUM>/<NUM>. , more preferably from <NUM> to <NUM>/<NUM> is not obtained by degrading (visbreaking) the polyolefin composition obtained from the polymerization reaction.

In some embodiments of the present disclosure, the fraction soluble in xylene at <NUM> of the polyolefin composition XS(tot) has intrinsic viscosity (XS(IV)) ranging from <NUM> to <NUM> dl/g, preferably from <NUM> to <NUM> dl/g.

In some embodiments of the present disclosure, the polyolefin composition comprises <NUM>-<NUM>% by weight of component (A) and <NUM>-<NUM>% by weight of component (B), the amounts of (A) and (B) being based on the total weight of the polyolefin composition, the total weight being <NUM>.

In a preferred embodiment of the present disclosure, the polyolefin composition comprises:.

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

In a preferred embodiment of the present disclosure, the polyolefin composition has Flexural Modulus, Strength at break, Charpy resistance at -<NUM>, puncture resistance, puncture deformation and Shore D values comprised in the ranges indicated above.

In some embodiments, the polyolefin composition is also endowed with at least one of the following properties measured on injection molded specimens:.

In some embodiments, the polyolefin composition is also endowed with at least one of the following properties, measured on <NUM>-thick extruded sheets:.

In one embodiment, the polyolefin composition is endowed with all the properties described above.

The properties disclosed above are measured on injection molded and extruded specimens obtained as described in the experimental part of the disclosure.

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

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 the catalyst being fed in the first polymerization stage.

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

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

In some preferred embodiments, the solid catalyst component (<NUM>) comprises a titanium compound of formula Ti(OR)nXy_n, wherein n is comprised between <NUM> and y; y is the valence of titanium; X is halogen and R is a hydrocarbon group having <NUM>-<NUM> carbon atoms or a -COR group. Among them, particularly preferred are titanium compounds having at least one Ti-halogen bond such as titanium tetrahalides or titanium halogenalcoholates. Preferred specific titanium compounds are TiCl<NUM>, TiCl<NUM>, Ti(OBu)<NUM>, Ti(OBu)Cl<NUM>, Ti(OBu)<NUM>Cl<NUM>, Ti(OBu)<NUM>Cl. TiCl<NUM> is particularly preferred.

In one embodiment, the solid catalyst component (<NUM>) comprises a titanium compound in an amount securing the presence of from <NUM> to <NUM>% by weight of Ti with respect to the total weight of the solid catalyst component (<NUM>).

The solid catalyst component (<NUM>) comprises at least one stereoregulating 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.

Particularly preferred are the electron donors belonging to aliphatic or aromatic mono- or dicarboxylic acid esters and diethers.

Among alkyl and aryl esters of optionally substituted aromatic polycarboxylic acids, preferred donors are the esters of phthalic acids such as those described in <CIT> and <CIT>.

In some embodiments, the internal electron donor is selected from the group consisting of mono- or di-substituted phthalates, wherein the substituents are independently selected among linear or branched C<NUM>-<NUM> alkyl, C<NUM>-<NUM> cycloalkyl and aryl radical.

In some preferred embodiments, the internal electron donor is selected among di-isobutyl phthalate, di-n-butyl phthalate, di-n-octyl phthalate, diphenyl phthalate, benzylbutyl phthalate and combinations thereof.

In one embodiment, the internal electron donor is di-isobutyl phthalate.

Esters of aliphatic acids can be selected from malonic acids such as those described in <CIT>, <CIT>, <CIT>, glutaric acids such as those disclosed in <CIT>, and succinic acids such as those disclosed <CIT>.

Particular type of diesters are those deriving from esterification of aliphatic or aromatic diols such as those described in <CIT> and <CIT>.

In some embodiments, the internal electron donor is selected from <NUM>,<NUM>-diethers of formula
<CHM>
wherein RI and RII are independently selected from C<NUM>-<NUM> alkyl, C<NUM>-<NUM> ccycloalkyl and C<NUM>-<NUM> aryl radicals, RIII and RIV are independently selected from C<NUM>-<NUM> alkyl radicals; or the carbon atom in position <NUM> of the <NUM>,<NUM>-diether belongs to a cyclic or polycyclic structure made up of from <NUM> to <NUM> carbon atoms, or of <NUM>-n or <NUM>-n' carbon atoms, and respectively n nitrogen atoms and n' heteroatoms selected from the group consisting of N, O, S and Si, where n is <NUM> or <NUM> and n' is <NUM>, <NUM>, or <NUM>, said structure containing two or three unsaturations (cyclopolyenic structures), and optionally being condensed with other cyclic structures, or substituted with one or more substituents selected from the group consisting of linear or branched alkyl radicals; cycloalkyl, aryl, aralkyl, alkaryl radicals and halogens, or being condensed with other cyclic structures and substituted with one or more of the above mentioned substituents that can also be bonded to the condensed cyclic structures, wherein one or more of the above mentioned alkyl, cycloalkyl, aryl, aralkyl, or alkaryl radicals and the condensed cyclic structures optionally contain one or more heteroatom(s) as substitutes for carbon and/or hydrogen atoms. Ethers of this type are described in <CIT>, <CIT> and <CIT>.

When <NUM>,<NUM>-diethers described above are used, the external electron donor (<NUM>) can be absent.

In some cases, specific mixtures of internal donors, in particular between aliphatic or aromatic mono or dicarboxylic acid esters and <NUM>,<NUM>-diethers as disclosed in <CIT> and <CIT> can be used as internal donor.

Preferred magnesium halide support is magnesium dihalide.

In one embodiment, the amount of internal electron donor which remains fixed on the solid catalyst component (<NUM>) is <NUM> to <NUM>% by moles, with respect to the magnesium dihalide.

Preferred methods for the preparation of the solid catalyst components start from Mg dihalide precursors that upon reaction with titanium chlorides converts the precursor into the Mg dihalide support. The reaction is preferably carried out in the presence of the steroregulating internal donor.

In a preferred embodiment the magnesium dihalide precursor is a Lewis adduct of formula MgCl<NUM>•nR1OH, where n is a number between <NUM> and <NUM>, and R1 is a hydrocarbon radical having <NUM>-<NUM> carbon atoms. Preferably, n ranges from <NUM> to <NUM> and more preferably from <NUM> to <NUM>.

The adduct can be suitably prepared by mixing alcohol and magnesium chloride, operating under stirring conditions at the melting temperature of the adduct (<NUM>-<NUM>).

Then, the adduct is mixed with an inert hydrocarbon immiscible with the adduct thereby creating an emulsion which is quickly quenched causing the solidification of the adduct in the form of spherical particles.

The so obtained adduct can be directly reacted with the Ti compound or it can be previously subjected to thermal controlled dealcoholation (<NUM>-<NUM>) so as to obtain an adduct in which the number of moles of alcohol is generally lower than <NUM> preferably between <NUM> and <NUM>. This controlled dealcoholation step may carried out in order to increase the morphological stability of the catalyst during polymerization and/or to increase the catalyst porosity as described in <CIT>.

The reaction with the Ti compound can be carried out by suspending the optionally dealcoholated adduct in cold TiCl<NUM> (generally at <NUM>). The mixture is heated up to <NUM>-<NUM> and kept at this temperature for <NUM>,<NUM>-<NUM> hours. The treatment with TiCl<NUM> can be carried out one or more times. The stereoregulating internal donor can be added during the treatment with TiCl<NUM>. The treatment with the internal donor can be repeated one or more times.

The preparation of catalyst components according to this general method is described for example in European Patent Applications <CIT>, <CIT>, <CIT> and as already mentioned, in <CIT>.

In one embodiment, the catalyst component (<NUM>) is in the form of spherical particles having an average diameter ranging from <NUM> to <NUM>, a surface area ranging from <NUM> to <NUM><NUM>/g, preferably from <NUM> to <NUM><NUM>/g and porosity greater that <NUM>/g, preferably of from <NUM> to <NUM>/g, wherein the surface area and the porosity are measured by BET.

In some preferred embodiments, the catalyst system comprises an Al-containing cocatalyst (<NUM>) selected from Al-trialkyls, preferably selected from the group consisting of Al-tryethyl, Al-triisobutyl and Al-tri-n-butyl.

In one embodiment, the Al/Ti weight ratio in the catalyst system is from <NUM> to <NUM>, preferably from <NUM> to <NUM>.

In a preferred embodiment, the catalyst system comprises a further electron donor compound (<NUM>) (external electron donor) selected among silicon compounds, ethers, esters, amines, heterocyclic compounds, particularly <NUM>,<NUM>,<NUM>,<NUM>-tetramethylpiperidine, and ketones.

Preferably, the external donor is selected among silicon compounds of formula (R2)a(R3)bSi(OR4)c, where a and b are integers from <NUM> to <NUM>, c is an integer from <NUM> to <NUM> and the sum (a+b+c) is <NUM>; R2, R3, and R4, are alkyl, cycloalkyl or aryl radicals with <NUM>-<NUM> carbon atoms, optionally containing heteroatoms. Particularly preferred are the silicon compounds in which a is <NUM>, b is <NUM>, c is <NUM>, at least one of R2 and R3 is selected from branched alkyl, cycloalkyl or aryl groups with <NUM>-<NUM> carbon atoms, optionally containing heteroatoms, and R4 is a C1-C10 alkyl group, in particular methyl.

Examples of such preferred silicon compounds are selected among methylcyclohexyldimethoxysilane (C-donor), diphenyldimethoxysilane, methyl-t-butyldimethoxysilane, dicyclopentyldimethoxysilane (D-donor), diisopropyldimethoxysilane, (<NUM>-ethylpiperidinyl)t-butyldimethoxysilane, (<NUM>-ethylpiperidinyl)thexyldimethoxysilane, (<NUM>,<NUM>,<NUM>-trifluoro-n-propyl)(<NUM>-ethylpiperidinyl)dimethoxysilane, methyl(<NUM>,<NUM>,<NUM>-trifluoro-n-propyl)dimethoxysilane and combinations thereof.

The silicon compounds in which a is <NUM>, c is <NUM>, R3 is a branched alkyl or cycloalkyl group, optionally containing heteroatoms, and R4 is methyl are also preferred. Examples of such silicon compounds are cyclohexyltrimethoxysilane, t-butyltrimethoxysilane and hexyltrimethoxysilane.

Even if several combinations of the components of the catalyst system allow to obtain the polyolefin compositions of the present disclosure, a particularly suitable catalyst system comprises di-isobutyl phthalate as internal electron donor and dicyclopentyl dimethoxy silane (D-donor) as external electron donor (<NUM>).

In one embodiment, the catalyst system is pre-contacted with small quantities of olefin (prepolymerization), maintaining the catalyst in suspension in a hydrocarbon solvent, and polymerizing at temperatures from <NUM>° to <NUM> producing a quantity of polymer from about <NUM> to about <NUM> times the weight of the catalyst system.

In an alternative embodiment, the prepolymerization is carried out in liquid monomer, producing a quantity of polymer <NUM> times the weight of the catalyst system.

Sequential polymerization processes for preparing the polyolefin compositions of the present disclosure are described in <CIT> and <CIT>, whose content is incorporated in this patent application for reference purposes.

The components (A) and (B) can be produced in any one of the polymerization stages.

In one embodiment, the polymerization process comprises polymerizations stages carried out in the presence of a highly stereospecific Ziegler-Natta catalyst system, wherein:.

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 the propylene copolymer (B1) in the stage (b1) and copolymer (B2) in the stage (b2).

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).

The polymerization, which can be continuous or batch, can be carried out according to known cascade techniques operating either in mixed liquid phase/gas phase or totally in gas phase.

The liquid-phase polymerization can be either in slurry, solution or bulk (liquid monomer). This latter technology 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.

The gas-phase polymerization stages can be carried out in gas-phase reactors, such as fluidized or stirred, fixed bed reactors.

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

In a preferred embodiment, also the copolymerization stage (a) is carried out in the gas phase.

In one embodiment, the reaction temperatures of the polymerization stages (a), (b), (b1) and (b2) are independently selected from values comprised in the range from <NUM>° to <NUM>.

In one embodiment, the polymerization pressure of the copolymerization stage (a) carried out in liquid phase is from <NUM> to <NUM> MPa.

In one embodiment, the polymerization pressure of the copolymerization stages (a), (b), (b1) and (b2) carried out in gas-phase is independently selected from values comprised in the range from <NUM> to <NUM> MPa.

The residence time of each polymerization stage depends upon the desired ratio of component (A) and (B), or of component (A), (B1) and (B2), of the polyolefin composition. In one embodiment, the residence time in each polymerization stage ranges from <NUM> minutes to <NUM> hours.

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

The molecular weight of the propylene copolymers obtained in the polymerization stages is regulated using chain transfer agents, such as hydrogen or ZnEt<NUM>.

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

In one embodiment, the polyolefin composition is an additivated polyolefin composition (AD1) comprising a total amount up to and including <NUM> % by weight, preferably <NUM>-<NUM>% by weight, with respect to the total amount of the additivated polyolefin composition (AD1), of at least one first additive (C) selected from the group consisting of antistatic agents, antioxidants, anti-acids, melt stabilizers and combinations thereof, of the type used in the polyolefin field.

In one embodiment, the polyolefin composition is an additivated polyolefin composition (AD1) consisting of component (A), component (B) and the at least one first additive (C), preferably in a total amount up to and including <NUM> % by weight, more preferably from <NUM> to <NUM>% by weight, with respect to the total amount of the additivated polyolefin composition (AD1), the total weight of the additivated polyolefin composition AD1 being <NUM>.

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

In one embodiment, the additivated polyolefin composition comprises up to and including <NUM>% by weight, preferably from <NUM> to <NUM>% by weight, more preferably from <NUM> to <NUM>% by weight, of the at least one second additive (D), the amount of the at least one second additive (D) being based on the total weight of the polyolefin composition comprising the additive (D), the total weight being <NUM>.

In some embodiments, the polyolefin composition is an additivated polyolefin composition (AD2) comprising component (A) and component (B) as described above, and.

wherein the amounts are (A) and (B) are based on the total weight of (A)+(B) and the amount of the first additive (C) and the second additive (D) are based on the total weight of the additivated polyolefin composition (AD2), the total weight being <NUM>.

In one embodiment, the first additive (C) and the second additive (D) are selected from the groups described above.

In one embodiment, the additivated polyolefin composition (AD2) consists of the components (A), (B), (C) and (D).

A further object of the present disclosure is a sheet or membrane comprising the polyolefin composition of the present disclosure.

In one embodiment, the sheet or membrane comprises the additivated polyolefin (AD1) or the additivated polyolefin composition (AD2).

In some embodiments, the sheet or membrane has total thickness in the range from <NUM> to <NUM>, preferably from <NUM> to <NUM>.

The sheet or membrane is a monolayer or a multilayer sheet or membrane.

In one embodiment, the sheet or membrane is a monolayer sheet or membrane comprising the polyolefin composition or the additivated polyolefin composition (AD1) or the additivated polyolefin composition (AD2).

In one embodiment, the monolayer sheet or membrane consists of the polyolefin composition or of the additivated polyolefin composition (AD1) or of the additivated polyolefin composition (AD2).

In some embodiments, the sheet or membrane is a multilayer sheet or membrane comprising at least one layer X, wherein the layer X comprises the polyolefin composition or the additivated polyolefin composition (AD1) or the additivated polyolefin composition (AD2).

In one embodiment, the layer X comprised in the multilayer sheet or membrane consists of the polyolefin composition or of the additivated polyolefin composition (AD1) or of the additivated polyolefin composition (AD2).

In one embodiment, the multilayer sheet or membrane comprises a layer X and a layer Y, wherein the layer X and the layer Y comprise a polyolefin independently selected from the group consisting of the polyolefin composition, the additivated polyolefin composition (AD <NUM>) and the additivated polyolefin composition (AD2).

In one embodiment, the multilayer sheet or membrane comprises a layer X and a layer Y, wherein the layer X and the layer Y consist of a polyolefin independently selected from the group consisting of the polyolefin composition, the additivated polyolefin composition (AD1), and the additivated polyolefin composition (AD2).

In one embodiment, the multilayer sheet or membrane consists of a layer X and of a layer Y, wherein the layer X and the layer Y comprise a polyolefin independently selected from the group consisting of the polyolefin composition, the additivated polyolefin composition (AD1), and the additivated polyolefin composition (AD2).

In one embodiment, the multilayer sheet or membrane consists of a layer X and of a layer Y, wherein the layer X and the layer Y consist of a polyolefin independently selected from the group consisting of the polyolefin composition, the additivated polyolefin composition (AD1), and the additivated polyolefin composition (AD2).

In one embodiment, the multilayer sheet or membrane has layers structure X/Z/Y, wherein the layer X and the layer Y are as described above, and the layer Z is a reinforcing layer comprising a plastic material selected from the group consisting of propylene homopolymers, propylene copolymers, polyethylene, polyethylene terephthalate and combinations thereof.

In one embodiment, the layer Z is a woven fabric or a non-woven fabric.

Monolayer sheets or membranes are obtainable by calendaring, extrusion or spread coating. In one preferred embodiment, the sheet or membrane is obtained by extrusion.

Multilayers sheets or membranes are obtainable by co-extrusion of the polyolefin comprised in the layers or by lamination of the layers.

In one embodiment, the sheet or membrane is a single-ply roofing sheet or membrane.

In one embodiment, the sheet or membrane is a geomembrane.

The features describing the subject matter of the present disclosure are not inextricably linked to each other. As a consequence, a certain level of preference of one feature does not necessarily involve the same level of preference of the remaining features. Furthermore, it forms part of the present disclosure any combination of parametric ranges and/or features, even though not explicitly described.

The following examples are illustrative only, and are not intended to limit the scope of the disclosure in any manner whatsoever.

The following methods are used to determine the properties indicated in the description, claims and examples.

Melt Flow Rate: Determined according to the method ISO <NUM> (<NUM>, <NUM>).

Solubility in xylene at <NUM>: <NUM> of polymer sample and <NUM> of xylene are introduced in a glass flask equipped with a refrigerator and a magnetic stirrer. The temperature is raised in <NUM> minutes up to <NUM>. The obtained clear solution is kept under reflux and stirring for further <NUM> minutes. The solution is cooled in two stages. In the first stage, the temperature is lowered to <NUM> in air for <NUM> to <NUM> minute under stirring. In the second stage, the flask is transferred to a thermostatically controlled water bath at <NUM> for <NUM> minutes. The temperature is lowered to <NUM> without stirring during the first <NUM> minutes and maintained at <NUM> with stirring for the last <NUM> minutes. The formed solid is filtered on quick filtering paper (eg. Whatman filtering paper grade <NUM> or <NUM>). <NUM> of the filtered solution (S1) is poured in a previously weighed aluminum container, which is heated to <NUM> on a heating plate under nitrogen flow, to remove the solvent by evaporation. The container is then kept on an oven at <NUM> under vacuum until constant weight is reached. The amount of polymer soluble in xylene at <NUM> is then calculated. XS(tot) and XSA values are experimentally determined. The fraction of component (B) soluble in xylene at <NUM> (XSB) can be calculated from the formula: <MAT> wherein W(A) and W(B) are the relative amounts of components (A) and (B), respectively, and W(A)+ W(B)=<NUM>.

Intrinsic viscosity of the xylene soluble fraction: to calculate the value of the intrinsic viscosity IV, the flow time of a polymer solution is compared with the flow time of the solvent (THN). A glass capillary viscometer of Ubbelohde type is used. The oven temperature is adjusted to <NUM>. Before starting the measurement of the solvent flow time t0 the temperature must be stable (<NUM>° ± <NUM>). Sample meniscus detection for the viscometer is performed by a photoelectric device. Sample preparation: <NUM> of the filtered solution (S1) is poured in a beaker and <NUM> of acetone are added under vigorous stirring. Precipitation of insoluble fraction must be complete as evidenced by a clear solid-solution separation. The suspension is filtered on a weighed metallic screen (<NUM> mesh), the beaker is rinsed and the precipitate is washed with acetone so that the o-xylene is completely removed. The precipitate is dried in a vacuum oven at <NUM> until a constant weight is reached. <NUM> of precipitate are weighted and dissolved in <NUM> of tetrahydronaphthalene (THN) at a temperature of <NUM>. The efflux time t of the sample solution is measured and converted into a value of intrinsic viscosity [η] using Huggins' equation (<NPL>) and the following data:.

One single polymer solution is used to determine [η].

Comonomer content: <NUM>C NMR spectra are acquired on a Bruker AV-<NUM> spectrometer equipped with cryoprobe, operating at <NUM> in the Fourier transform mode at <NUM>. The peak of the Sδδ carbon (nomenclature according to "<NPL>) is used as an internal reference at <NUM> ppm. The samples are dissolved in <NUM>,<NUM>,<NUM>,<NUM>-tetrachloroethane-d2 at <NUM> with a <NUM> % wt/v concentration. Each spectrum is acquired with a <NUM>° pulse, and <NUM> seconds of delay between pulses and CPD to remove <NUM>H-<NUM>C coupling. <NUM> transients are stored in <NUM> data points using a spectral window of <NUM>. The assignments of the spectra, the evaluation of triad distribution and the composition are made according to Kakugo ("<NPL>) using the following equations: <MAT> <MAT> <MAT> The molar content of ethylene and propylene is calculated from triads using the following equations: <MAT> <MAT> The weight percentage of ethylene content (E% wt) is calculated using the following equation: <MAT> wherein.

The product of reactivity ratio r<NUM>r<NUM> is calculated according to Carman (<NPL>) as: <MAT> The tacticity of propylene sequences is calculated as mm content from the ratio of the PPP mmTββ (<NUM>-<NUM> ppm) and the whole Tββ (<NUM>-<NUM> ppm). The amount of ethylene of component B) is calculated from the total ethylene content of the polymer (C2(tot)) using the formula: <MAT> wherein W(A) and W(B) are the relative amounts of components (A) and (B) (W(A)+W(B)=<NUM>), and C2(A) and C2(B) are the weight percentages of ethylene in component (A) and (B).

Injection molded specimens: test specimens <NUM> × <NUM> × <NUM> were obtained according to the method ISO <NUM>-<NUM>:<NUM>.

Flexural modulus: Determined according to the method ISO <NUM>:<NUM> on injection molded test specimens.

Strength and Elongation at break: Determined according to the method ISO <NUM> on injection molded test specimens.

Shore A and D on injection molded specimens: Determined according to the method ISO <NUM> (<NUM> sec).

Vicat softening temperature: Determined according to the method ISO <NUM> (A50) on injection molded specimens.

Charpy Impact test at -<NUM>: measured according to ISO <NUM>/1eA <NUM> on injection molded specimens.

Tensile Modulus (MD and TD): Determined according to the method ISO <NUM>-<NUM> on <NUM>-thick extruded sheets. Specimens type <NUM>, Crosshead speed: <NUM>/min.

Tensile strength and elongation at break (MD and TD): Determined according to the method ISO527-<NUM> on <NUM>-thick extruded sheets. Specimens type: <NUM>, Crosshead speed: <NUM>/min.

Tear resistance: Determined according to the method ASTM D <NUM> on <NUM>-thick extruded sheets. Crosshead speed: <NUM>/min; V-shaped die cut specimen.

Puncture resistance and deformation: Determined according to the method ASTM D <NUM> on <NUM>-thick extruded sheets. Punch diameter <NUM>, crosshead speed: <NUM>/min.

Shore A and D on extruded sheets: Determined according to the method ISO <NUM> (<NUM> sec) on <NUM>-thick extruded sheets.

Preparation of extruded specimens: the polymer in form of granules are fed via feed hoppers into a Leonard extruder (mono-screw extruder, <NUM> in diameter and <NUM> LID in length) where the polymer was first melted (melt temperature <NUM>), compressed, mixed and finally metered out at a throughput rate of <NUM>/h with a metering pump (<NUM> cc/rpm). The molten polymer leaves the flat die (width <NUM>, die lip at <NUM>-<NUM>) and is instantly cooled through a vertical three-rolls calendrer having roll-temperature of <NUM>. <NUM>-thick extruded sheets are obtained.

The polymerization was carried out in two gas phase reactors connected in series and equipped with devices to transfer the product from the first to the second reactor.

For the polymerization a Ziegler-Natta catalyst system was used comprising:.

The solid catalyst component was contacted with TEAL and DCPMS in a precontacting vessel, with a weight ratio of TEAL to the solid catalyst component of <NUM>-<NUM> and a weight ratio TEAL/DCPMS of <NUM>.

The catalyst system was then subjected to pre-polymerization by maintaining it in suspension in liquid propylene at <NUM> for about <NUM>-<NUM> minutes before introducing it into the first polymerization reactor.

Propylene copolymer (A) was produced into the first gas-phase reactor by feeding in a continuous and constant flow the pre-polymerized catalyst system, hydrogen (used as molecular weight regulator), propylene and ethylene all in gaseous phase.

The propylene copolymer (A) coming from the first reactor was discharged in a continuous flow and, after having been purged of unreacted monomers, was introduced, in a continuous flow, into the second gas-phase reactor, together with quantitatively constant flows of hydrogen and ethylene, all in the gas state.

In the second reactor the propylene copolymer (B) was produced.

Polymerization conditions, molar ratio of the reactants and composition of the copolymers obtained are shown in Table <NUM>.

Notes: C2- = ethylene in gas phase (IR); C3- = propylene in gas phase (IR); split = amount of polymer produced in the concerned reactor. (*) Calculated values.

The polymer particles exiting the second reactor were subjected to a steam treatment to remove the unreacted monomers and volatile compounds, and then dried.

The thus obtained polyolefin composition was mixed with the additives in a twin screw extruder Berstorff ZE <NUM> (length/diameter ratio of screws: <NUM>) and extruded under nitrogen atmosphere in the following conditions:.

The additives added to the polyolefin composition were:.

wherein the amounts of additives are based on the total weight of the polyolefin composition containing the additives.

Irganox® <NUM> is <NUM>,<NUM>-bis[<NUM>-[,<NUM>-bis(<NUM>,<NUM>-dimethylethyl)-<NUM>-hydroxyphenyl]-<NUM>-oxopropoxy]methyl]-<NUM>,<NUM>-propanediyl-<NUM>,<NUM>-bis(<NUM>,<NUM>-dimethylethyl)-<NUM>-hydroxybenzene-propanoate; Irgafos® <NUM> is tris(<NUM>,<NUM>-di-tert. -butylphenyl) phosphite; DHT-4A® is Magnesium Aluminum Carbonate Hydroxide (hydrate).

Properties of the materials tested on injection molded specimens are reported in Table <NUM>. Properties of the material tested on extruded sheets are reported in table <NUM>.

Using the same catalyst system of example <NUM>, polyolefin compositions were prepared in three gas phase reactors connected in series and equipped with devices to transfer the product from one reactor to the subsequent reactor.

In the second reactor the propylene copolymer (B1) was produced. The product coming from the second reactor was discharged in a continuous flow and, after having been purged of unreacted monomers, was introduced, in a continuous flow, into the third gas-phase reactor, together with quantitatively constant flows of hydrogen, ethylene and propylene, all in the gas state. In the third reactor an ethylene-propylene polymer (B2) was produced.

Polymerization conditions, molar ratios of the reactants and composition of the copolymers obtained are shown in Table <NUM>.

The polymer particles exiting the third reactor were subjected to a steam treatment to remove the unreacted monomers and volatile compounds, dried and melt-mixed with additives as described in example <NUM>.

Properties of the materials tested on injection molded specimens are reported in Table <NUM>. Properties of the material tested on extruded sheets are reported in Table <NUM>.

Claim 1:
A polyolefin composition comprising:
(A) <NUM>-<NUM>% by weight of a copolymer of propylene with at least one alpha-olefin of formula CH<NUM>=CHR, where R is H or a linear or branched C2-C3 alkyl, wherein
i) the copolymer contains <NUM>-<NUM>% by weight of at least one alpha-olefin, the amount of the alpha-olefin is based on the total weight of (A); and
ii) the propylene copolymer has melt flow rate (MFRA), measured according to ISO <NUM>, <NUM>, <NUM>, ranging from <NUM> to <NUM>/<NUM>; and
(B) <NUM>-<NUM>% by weight of a copolymer of propylene with at least one alpha-olefin of formula CH<NUM>=CHR, and optionally a diene, where R is H or a linear or branched C2-C8 alkyl and wherein the copolymer comprises <NUM>-<NUM>% by weight of alpha-olefin, the amount of alpha olefin is based on the total weight of (B),
wherein
iii) the polyolefin composition comprises a fraction that is soluble in xylene at <NUM> (XS(tot)) in an amount higher than <NUM>% by weight;
iv) the amounts of (A), (B) and of the fraction soluble in xylene at <NUM> (XS(tot)) are based on the total weight of the polyolefin composition; and
v) the melt flow rate (MFR), measured according to ISO <NUM>, <NUM>, <NUM>, of the polyolefin composition ranges from <NUM> to <NUM>/<NUM>.