Polyethylene polymers for film layers

Abstract

The present invention relates to metallocene catalyzed multimodal polyethylene polymers (P), the use of multimodal polymers (P) of ethylene in membrane applications and membranes comprising the polymers (P) of the invention.

Description

[0001] The present invention relates to metallocene-catalyzed multimodal polyethylene polymers (P), the use of multimodal polyethylene polymers (P) in film applications and films comprising the polymers (P) of the invention.

[0002] State-of-the-art mLLDPE (metallocene-catalyzed linear low-density polyethylene) is widely used in daily life, such as packaging, due to its excellent price-performance ratio. A well-known disadvantage is the narrow molecular weight distribution and thus less shear thinning, which leads to problems in film conversion, such as limiting the output.

[0003] WO 2021009189, WO 2021009190 and WO 2021009191 of Borealis disclose processes for producing multimodal PE polymers in a double loop reactor and a gas phase reactor.

[0004] The total density of the polymer prepared in the example is 938 or 939 kg / m 3 The MFR2 (190°C, 2.16 kg, ISO 1133) of the polymer component produced in the first loop reactor was 22 g / 10 min. Film properties such as tensile modulus (TM), tear resistance and dart impact strength (DDI) are not mentioned at all.

[0005] WO 2021009192 also discloses this method. The polymer prepared in the example has a mass fraction of 951 kg / m 3 The MFR2 (190°C, 2.16 kg, ISO 1133) of the polymer component produced in the first loop is 32 g / 10 min. Film properties such as tensile modulus (TM), tear resistance and dart impact strength (DDI) are not mentioned at all.

[0006] Although a lot of development work has been done in this area, there is still a need to find multimodal PE polymers with different property balances to provide customized solutions that meet the growing needs of end-use manufacturers, such as reducing production costs while maintaining or even improving the properties of the end product. Customized polymer solutions are also needed to meet the requirements of evolving equipment technology in the end-use application field.

[0007] A common problem with tailoring properties is that improvement in one property often results in a deterioration in another, e.g. by increasing stiffness, toughness often decreases.

[0008] Therefore, there is a need in the art to provide a material that offers a good balance of mechanical properties, particularly tensile modulus, tear resistance and dart drop (impact strength).

[0009] In other words, there is a need for a material that provides a favorable combination of tensile modulus, tear resistance, and dart impact strength for films prepared from such materials.

[0010] Furthermore, such membranes should further exhibit well-balanced and continually improved overall properties.

[0011] Such improvement in the overall properties of the blown film can be expressed by the photomechanical ability (OMA), which is the ratio of mechanical (especially tear resistance (TD) and tensile modulus (TD)) properties to optical properties (ie haze).

[0012] It has now been found that metallocene-catalyzed multimodal polyethylene polymers (P) prepared with specific metallocene catalysts and having a specific polymer design have desirable improved properties.

[0013] Films made from such metallocene-catalyzed multimodal polyethylene polymers (P) additionally have an improved balance of properties, especially improved overall properties. Summary of the invention

[0014] Accordingly, the present invention relates to a metallocene-catalyzed multimodal polyethylene polymer consisting of:

[0015] (i) 35.0 to 50.0 wt% of a polyethylene component (A), and

[0016] (ii) 50.0 to 65.0 wt% of a polyethylene component (B),

[0017] The polyethylene component (A) has

[0018] 952 to 970 kg / m 3 Density in the range (ISO 1183),

[0019] an MFR2 (190°C, 2.16 kg, ISO 1133) in the range of 1.0 to 15.0 g / 10 min, a 1-butene content (in terms of 13 C{ 1 H}NMR determination) and

[0020] The polyvinyl polymer component (A) is composed of an ethylene polymer portion (A-1) and an ethylene polymer portion (A-2), wherein the ethylene polymer portion (A-1) has

[0021] 945 to 965 kg / m 3range (ISO 1183) and an MFR2 (190°C, 2.16 kg, ISO 1133) in the range of 0.5 to 8.0 g / 10 min; and

[0022] The ethylene polymer portion (A-2) has a carbon content of 950 to 970 kg / m 3 Density in the range of 1.0 to 15.0 g / 10 min (190°C, 2.16 kg, ISO 1133),

[0023] The polyethylene component (B) has

[0024] 900 to 940 kg / m 3 Density in the range (ISO 1183),

[0025] An MFR2 (190°C, 2.16 kg, ISO 1133) in the range of 0.01 to 2.0 g / 10 min, a 1-hexene content (using 13 C{ 1 H}NMR determination);

[0026] wherein the multimodal polyethylene polymer (P) has

[0027] 927 to 950 kg / m 3 Density in the range (ISO 1183),

[0028] MFR2 (190°C, 2.16kg, ISO 1133) in the range of 0.1 to 3.0 g / 10min,

[0029] Molecular weight distribution (Mw / Mn) determined by GPC in the range of 4.6 up to 7.0,

[0030] The ratio Mw(Tp(LCF) of the molecular weight (Mw) of the low crystalline fraction (LCF) to the molecular weight (Mw) of the high crystalline fraction (HCF) determined as described in the experimental section is in the range of 0.8 to 4.0

[0031] / Mw(Tp(HCF).

[0032] Surprisingly, the multimodal polyethylene polymer (P) of the present invention provides improved mechanical properties to the film, such as high tensile modulus and or high dart impact strength and at the same time improved tear resistance.

[0033] Therefore, the present invention further relates to a film comprising at least one layer comprising a metallocene-catalyzed multimodal polyethylene polymer (P).

[0034] In another embodiment of the present invention, the membrane is according to formula (I):

[0035]

[0036] The photomechanical ability (OMA) measured on a 40 μm test blown film is at least 2000 [MPa * g / %]

[0037] Up to 8000[MPa * g / %], preferably 2100[MPa * g / %] to up to 6500[MPa * g / %], more preferably 2200 [MPa * g / %] to up to 5500[MPa * g / %], wherein the tensile modulus in the longitudinal direction is measured according to ISO 527-3 at 23° C. on a 40 μm test blown film, the tear resistance in the transverse direction is determined according to ISO 6383-2 on a 40 μm test blown film, and the haze is measured according to ASTM D1003 on a 40 μm test blown film.

[0038] definition

[0039] Where the term "comprising" is used in the present description and claims, it does not exclude other, not specifically stated, elements of major or minor functional importance. For the purposes of the present invention, the term "consisting of" is considered to be a preferred embodiment of the term "comprising". If a group is defined hereinafter as comprising at least a certain number of embodiments, this is also to be understood as disclosing the group, which preferably consists only of these embodiments.

[0040] Whenever the terms "including" or "having" are used, these terms are meant to be equivalent to "comprising" as defined above.

[0041] When an indefinite or definite article is used when referring to a singular noun, for example "a", "an" or "the", this includes a plural of that noun unless otherwise stated.

[0042] Metallocene-catalysed multimodal polyethylene polymer is defined in the present invention as a multimodal polyethylene polymer (P) produced in the presence of a metallocene catalyst.

[0043] In contrast to Ziegler Natta catalysis, polyethylene polymers produced in the presence of metallocene catalysts have characteristics that distinguish them from Ziegler Natta materials. In particular, the comonomer distribution is more uniform. This can be shown using TREF or Crystaf techniques. Catalyst residues can also be indicative of the catalyst used. For example, Ziegler Natta catalysts do not contain Zr or Hf Group (IV) metals.

[0044] For the purposes of the present invention, "multimodal polyethylene polymer (P) comprising a polyethylene component (A) and a polyethylene component (B)" means that the polymer is produced in at least a two-stage sequential polymerization process, wherein first component (A) is produced and then, in a subsequent polymerization step, component (B) is produced in the presence of component (A) to produce polymer (P), or vice versa, i.e. first component (B) is produced and then, in a subsequent polymerization step, component (A) is produced in the presence of component (B) to produce polymer (P).

[0045] Polymers produced in a multistage process are also referred to as "in-situ" blends or "reactor" blends. The resulting final product consists of an intimate mixture of polymers from two or more reactors whose different molecular weight distribution curves together form a molecular weight distribution curve with a broad maximum or two or more maxima, i.e., the final product is a multimodal polymer mixture.

[0046] In the context of a multimodal polyethylene polymer (P), the term "multimodal" refers herein to multimodality with respect to the melt flow rate (MFR) of the ethylene polymer components (A) and (B), i.e. the polyethylene components (A) and (B) have different MFR values. The multimodal polyethylene polymer (P) may further have multimodality with respect to one or more other properties between the polyethylene components (A) and (B), as described below.

[0047] The multimodal polyethylene polymer (P) of the invention as defined above, below or in the claims is herein also referred to as "multimodal PE" or "multimodal polymer (P)" for short.

[0048] The following preferred embodiments, properties and subgroups of the multimodal PE and its polyethylene components (A) and (B), and ethylene polymer fractions (A-1) and (A-2) and the inventive films including preferred ranges thereof are independently generalizable such that they can be used in any order or combination to further define preferred embodiments of the inventive multimodal PE and articles.

[0049] Multimodal PE and polyethylene fractions (A) and (B) and ethylene polymer fractions (A-1) and (A-2)

[0050] The metallocene produced multimodal polyethylene polymer (P) is referred to herein as "multimodal" because the polyethylene component (A), comprising the ethylene polymer fractions (A-1) and (A-2), and the ethylene-1-hexene polymer component (B) have been produced under different polymerisation conditions, resulting in different melt flow rates (MFR, e.g. MFR2). That is, the multimodal PE is multimodal at least with respect to the difference in MFR of the polyethylene components (A) and (B).

[0051] The metallocene produced multimodal polyethylene polymer (P) consists of

[0052] (i) 35.0 to 50.0 wt% of a polyethylene component (A), and

[0053] (ii) 50.0 to 65.0 wt% of a polyethylene component (B).

[0054] The amounts of (A) and (B) add up to 100.0 wt%.

[0055] The polyethylene component (A) consists of ethylene polymer fractions (A-1) and (A-2), wherein the MFR2 of the ethylene polymer fractions (A-1) and (A-2) may be different from each other or may be the same, preferably the MFR2 of the two fractions are different.

[0056] The MFR2 (190°C, 2.16 kg, ISO 1133) of the ethylene polymer portion (A-1) is in the range of 0.5 to 8.0 g / 10 min, preferably 0.6 to 7.5 g / 10 min, more preferably 0.8 to 7.0 g / 10 min, most preferably 1.0 to 7.0 g / 10 min.

[0057] The ethylene polymer portion (A-2) has an MFR2 (190°C, 2.16 kg, ISO 1133) in the range of 1.0 to 15.0 g / 10 min, preferably 1.5 to 12.0 g / 10 min, more preferably 2.0 to 10.0 g / 10 min, even more preferably 2.5 to 9.5 g / 10 min, most preferably 3.0 to 9.0 g / 10 min.

[0058] The MFR2 of the polyethylene components (A) and (B) are different from each other.

[0059] The MFR2 (190°C, 2.16 kg, ISO 1133) of the ethylene polymer component (A) is in the range of 1.0 to 15.0 g / 10 min, preferably 1.5 to 10.0 g / 10 min, more preferably 2.0 to 8.0 g / 10 min, even more preferably 2.5 to 7.0 g / 10 min.

[0060] The MFR2 (190°C, 2.16 kg, ISO 1133) of the ethylene polymer component (B) is in the range of 0.01 to 2.0 g / 10 min, preferably 0.03 to 1.6 g / 10 min, more preferably 0.05 to 1.2 g / 10 min, even more preferably 0.06 to 1.0 g / 10 min, such as 0.07 to 0.8 g / 10 min.

[0061] The multimodal polymer (P) has an MFR2 (190°C, 2.16 kg, ISO 1133) in the range of 0.1 to 3.0 g / 10 min, preferably 0.2 to 2.5 g / 10 min, more preferably 0.3 to 2.0 g / 10 min.

[0062] In one embodiment of the present invention, the MFR of the multimodal polymer (P) 21 / MFR2 ratio (MFR 21 Measured according to ISO 1133 at 190°C and 21.6 kg) is in the range of 20.0 to 40.0, preferably 22.0 to 35.0, more preferably 24.0 to 32.0.

[0063] Of course, in addition to the multimodality with respect to (i.e. the difference between) the MFR2 of the polyethylene components (A) and (B), the multimodal PE of the present invention may also be multimodal with respect to, for example, one or both of the two other properties:

[0064] Regarding the multimodality of the following, i.e., the differences between them,

[0065] - the content and or type of comonomers present in polyethylene components (A) and (B); and / or

[0066] - The density of the polyethylene components (A) and (B).

[0067] Preferably, the multimodal polymer (P) is further multimodal with respect to the comonomer content and the comonomer type of the polyethylene components (A) and (B).

[0068] According to the present invention, the polyethylene component (A) is preferably a polyethylene homopolymer.

[0069] For the purposes of the present invention, a polyethylene homopolymer refers to a polymer comprising at least 99.0 wt%, in particular at least 99.5 wt% of ethylene monomer units. Thus, a polyethylene homopolymer may contain up to 1.0 wt%, but preferably only up to 0.5 wt%, for example up to 0.2 wt% or even only up to 0.1 wt% of comonomers.

[0070] The comonomer optionally present in the polyethylene component (A) is 1-butene.

[0071] The comonomer type of polymer fractions (A-1) and (A-2) is the same, so both fractions have 1-butene as a comonomer.

[0072] The comonomer content of components (A) and (B) can be measured or, in a preferred case, in a so-called multi-stage process, one component is first produced and then the other component is produced in the presence of the first component, then the comonomer content of the first produced component, e.g. component (A), can be measured and the comonomer content of the other component, e.g. component (B), can be calculated according to the following formula:

[0073] Comonomer content in component B (mol%) = (comonomer content in final product (mol%)

[0074] -(weight fraction of component A * Comonomer content in component A (mol%) / (weight fraction of component B)

[0075] The total amount of 1-butene is preferably in the range of 0.01 to 0.10 mol-%, preferably 0.02 to 0.08 mol-%, more preferably 0.02 to 0.06 mol-%, based on the multimodal polymer (P).

[0076] The total amount of 1-hexene, based on the multimodal polymer (P), is preferably in the range of 0.1 to 3.0 mol-%, preferably 0.2 to 2.0 mol-%, more preferably 0.3 to 1.2 mol-%.

[0077] The total amount (mol%) of 1-butene present in the polyethylene component (A) is 0.01 to 0.20 mol%, preferably 0.02 to 0.15 mol%, more preferably 0.03 to 0.10 mol%, based on the polyethylene component (A).

[0078] The total amount (mol%) of 1-hexene present in the polyethylene component (B) is 0.2 to 5.0 mol%, preferably 0.3 to 3.0 mol%, more preferably 0.4 to 2.0 mol%, based on the polyethylene component (B).

[0079] Even more preferably, the multimodal polymer (P) of the present invention is further multimodal with respect to the density difference between polyethylene component (A) and polyethylene component (B). Preferably, the density of polyethylene component (A) is different from, preferably higher than, the density of polyethylene component (B).

[0080] The density of the polyethylene component (A) is between 952 and 970 kg / m 3 , preferably 953 to 968 kg / m 3 , more preferably 955 to 965 kg / m 3The density of the polyethylene component (B) is in the range of 900 to 940 kg / m 3 , preferably 905 to 935 kg / m 3 , more preferably 910 to 930 kg / m 3 within the range.

[0081] The density of the polymer part (A-1) is 945 to 965 kg / m 3 , preferably 948 to 962 kg / m 3 , more preferably 950 to 960 kg / m 3 within the range.

[0082] The density of the polymer part (A-2) is 950 to 970 kg / m 3 , preferably 955 to 965 kg / m 3 within the range.

[0083] The densities of the polymer parts (A-1) and (A-2) may be the same as or may be different from each other.

[0084] The metallocene-catalyzed multimodal polymer (P) is preferably a linear low density polyethylene (LLDPE) which has a well-known meaning.

[0085] The density of the multimodal polymer (P) is between 927 and 950 kg / m 3 , preferably 930.0 to 945 kg / m 3 , more preferably 932.0 to 942.0 kg / m 3 within the range.

[0086] More preferably, the multimodal polymer (P) is multimodal (i.e. there is a difference between them) at least with respect to MFR2, the comonomer content and the density of the polyethylene components (A) and (B) are multimodal (i.e. there is a difference between them), as defined above, below or in the claims, the claims including any preferred ranges or embodiments of the polymer composition.

[0087] Furthermore, the multimodal polymer (P) has a molecular weight distribution (Mw / Mn) determined by GPC in the range of at least 4.6 to at most 7.0, preferably in the range of 4.8 to 6.8, more preferably in the range of 5.0 to 6.5.

[0088] Furthermore, the ratio of the molecular weight (Mw) of the low crystalline fraction (LCF) to the molecular weight (Mw) of the high crystalline fraction (HCF) of the multimodal polymer (P), Mw(Tp(LCF) / Mw(Tp(HCF), determined as described in the experimental part, is in the range of 0.8 to 4.0, preferably in the range of 0.9 to 3.5, more preferably in the range of 1.0 to 3.0.

[0089] In one embodiment of the present invention, the half width of the low crystalline part (LCF) in the TREF curve for LogM>5.2 of the multimodal polymer (P) is in the range of 2.0 to 15.0, preferably 3.0 to 12.0, more preferably 3.5 to 10.0, even more preferably 4.0 to 9.0.

[0090] Definition of High Crystalline Fraction (HCF) and Low Crystalline Fraction (LCF):

[0091] The high crystalline fraction (HCF) is the amount, in wt%, of the polymer fraction having a crystallization temperature above 90°C, which contains mainly homopolyethylene chains or chains with a very low branching content.

[0092] The low crystalline fraction (LCF) is the amount of the polymer fraction having a crystallization temperature of 30 to below 90°C, expressed in wt%.

[0093] Within the scope of the present invention, the first and second ethylene polymer parts (A-1 and A-2) of the polyethylene component (A) are present in a weight ratio of 4:1 to 1:4, such as 3:1 to 1:3, or 2:1 to 1:2, or 1:1.

[0094] The polyethylene component (A) is present in an amount of 35.0 to 50.0 wt%, preferably in an amount of 36.0 to 48.0 wt%, even more preferably in an amount of 38.0 to 45.0 wt%, based on the multimodal copolymer (P).

[0095] Accordingly, the polyethylene component (B) is present in an amount of 50.0 to 65.0 wt%, preferably in an amount of 52.0 to 64.0 wt%, more preferably in an amount of 55.0 to 62.0 wt%, based on the multimodal polymer (P).

[0096] The multimodal polymer (P) may be produced in a three stage process, which preferably comprises a first slurry reactor (loop reactor 1), wherein the first slurry loop reactor is connected in series to a further slurry reactor (loop reactor 2), such that the first ethylene polymer fraction (A-1 ) produced in loop reactor 1 is fed to loop reactor 2, where the second ethylene polymer fraction (A-2) is produced in the presence of the first fraction (A-1 ). Thus, loop reactor 2 is connected in series to a gas phase reactor (GPR), such that the polyethylene fraction (A) leaving the second slurry reactor is fed to the GPR, to produce a trimodal polyethylene polymer. In this case, the reaction conditions in the two slurry reactors are selected such that products different in MFR and / or density are produced in the two slurry reactors.

[0097] Such processes are described in particular in WO 2016 / 198273, WO 2021009189, WO 2021009190, WO 2021009191 and WO 2021009192. Full details on how to prepare suitable metallocene-catalyzed multimodal copolymers (P) can be found in these references.

[0098] A suitable process is the Borstar PE process or the Borstar PE 3G process.

[0099] Therefore, the metallocene-catalyzed multimodal polymer (P) according to the present invention is preferably produced in a loop-loop-gas phase cascade. Such a polymerization step may be preceded by a prepolymerization step. The purpose of the prepolymerization is to polymerize a small amount of polymer onto the catalyst at low temperature and / or low monomer concentration. By prepolymerization, the performance of the catalyst in slurry can be improved and / or the properties of the final polymer can be modified. The prepolymerization step is preferably carried out in slurry and the amount of polymer produced in the optional prepolymerization step is counted as the amount (wt%) of ethylene polymer component (A).

[0100] When there is a prepolymerization step, the catalyst components are preferably all introduced into the prepolymerization step. However, when the solid catalyst component and the cocatalyst can be fed separately, it is possible that only a part of the cocatalyst is introduced into the prepolymerization stage, while the rest is introduced into the subsequent polymerization stage. Moreover, in this case, it is necessary to introduce so much cocatalyst into the prepolymerization stage in order to obtain a sufficient polymerization reaction therein.

[0101] It is to be understood that within the scope of the present invention the amount of polymer produced in the prepolymerisation is within 1 to 5 wt% relative to the final metallocene-catalysed multimodal polymer (P). This may be counted as part of the first ethylene polymer component (A).

[0102] catalyst

[0103] The metallocene-catalyzed multimodal polymer (P) used in the process of the present invention is prepared using a metallocene catalyst. The metallocene catalyst comprises a metallocene complex and a cocatalyst. The metallocene compound or complex is also referred to herein as an organometallic compound (C).

[0104] The organometallic compound (C) comprises a transition metal (M) from Groups 3 to 10 of the Periodic Table of Elements (IUPAC 2007) or from the actinides or lanthanides.

[0105] According to the present invention, the term "organometallic compound (C)" includes any metallocene or non-metallocene compound of a transition metal, which carries at least one organic (coordinating) ligand and exhibits catalytic activity alone or together with a cocatalyst. Transition metal compounds are well known in the art, and the present invention encompasses compounds of metals from Groups 3 to 10, e.g. Groups 3 to 7, or Groups 3 to 6, e.g. Groups 4 to 6, of the Periodic Table (IUPAC 2007), as well as lanthanides or actinides.

[0106] In one embodiment, the organometallic compound (C) has the following formula (II):

[0107]

[0108] Wherein each X is independently a halogen atom, C 1-6 -alkyl, C 1-6 - alkoxy, phenyl or benzyl;

[0109] Each Het is independently a monocyclic heteroaromatic group containing at least one heteroatom selected from O or S; L is -R'2Si-, wherein each R' is independently a C substituted by an alkoxy group having 1 to 10 carbon atoms; 1-20 -Hydrocarbon or C 1-10 -alkyl;

[0110] M is Ti, Zr or Hf;

[0111] Each R 1 Same or different, is C 1-6 -alkyl or C 1-6 - alkoxy;

[0112] Each n is 1 to 2;

[0113] Each R 2 Same or different, is C 1-6 -alkyl, C 1-6 -alkoxy or -Si(R)3 group;

[0114] Each R is optionally replaced by 1 to 3 C 1-6 -alkyl substituted C 1-10 - alkyl or phenyl; and

[0115] Each p is from 0 to 1.

[0116] Preferably, the compound of formula (II) has the structure

[0117]

[0118] Wherein each X is independently a halogen atom, C 1-6 -alkyl, C 1-6-alkoxy, phenyl or benzyl; L is Me2Si-;

[0119] Each R 1 Same or different and C 1-6 - alkyl, such as methyl or tert-butyl; each n is 1 to 2;

[0120] R 2 is -Si(R)3alkyl; each p is 1;

[0121] Each R is C 1-6 -alkyl or phenyl.

[0122] Highly preferred complexes of formula (II) are

[0123]

[0124] Most preferably, the complex dimethylsilanediylbis[2-(5-trimethylsilylfuran-2-yl)-4,5-dimethylcyclopentadien-1-yl]zirconium dichloride is used.

[0125] More preferably, the polyethylene components (A) and (B) of the multimodal polymer (P) are produced using, ie in the presence of, the same metallocene catalyst.

[0126] To form the catalyst, a cocatalyst, also called an activator, well known in the art is used. Cocatalysts containing Al or B are well known and can be used here. Preferably, an aluminoxane (such as MAO) or a boron-based cocatalyst (such as a borate) is used.

[0127] The metallocene-catalyzed multimodal polymer (P) may contain other polymer components and optionally additives and / or fillers. In case the metallocene-catalyzed multimodal polymer (P) contains other polymer components, the amount of the other polymer components typically varies between 3.0 and 20.0 wt.-%, based on the total amount of the metallocene-catalyzed multimodal polymer (P) and the other polymer components.

[0128] Optional additives and fillers and the amounts used are conventional in the field of film applications. Examples of such additives are, inter alia, antioxidants, processing stabilizers, UV stabilizers, pigments, fillers, antistatic additives, antiblocking agents, nucleating agents, acid scavengers and polymer processing aids (PPAs).

[0129] It is to be understood herein that any additive and / or filler may optionally be added to a so-called masterbatch comprising the respective additive and a carrier polymer. In this case, the carrier polymer is not calculated in the polymer component of the metallocene-catalyzed multimodal polymer (P) but in the amount of the respective additive, based on the total amount of the polymer composition (100 wt%).

[0130] The film of the present invention

[0131] The film of the present invention comprises at least one layer comprising a metallocene-catalyzed multimodal polymer (P). The film may be a monolayer film comprising a metallocene-catalyzed multimodal polymer (P) or a multilayer film, wherein at least one layer comprises a metallocene-catalyzed multimodal polymer (P). The terms "monolayer film" and "multilayer film" have well-known meanings in the art.

[0132] The monolayer film or the layers of the multilayer film of the present invention may consist of the metallocene-catalyzed multimodal polymer (P) itself or of a blend of said metallocene-catalyzed multimodal polymer (P) with other polymers. In the case of a blend, any other polymer is different from the metallocene-catalyzed multimodal polymer (P) and is preferably a polyolefin. Some of the above-mentioned additives, such as processing aids, may optionally be added to the metallocene-catalyzed multimodal polymer (P) during the film preparation process.

[0133] Preferably, at least one layer of the present invention comprises at least 50 wt%, more preferably at least 60 wt%, even more preferably at least 70 wt%, yet more preferably at least 80 wt% of the metallocene-catalyzed multimodal polymer (P) of the present invention. Most preferably, said at least one layer of the film of the present invention consists of the metallocene-catalyzed multimodal polymer (P).

[0134] Thus, the films of the invention may comprise a single layer (ie a monolayer) or may be multilayer.Multilayer films typically and preferably comprise at least 3 layers.

[0135] The film is preferably produced by any conventional film extrusion process known in the art, including cast film and blown film extrusion. Most preferably, the film is a blown film or cast film, especially a blown film. For example, blown film is produced by extruding through an annular die and blowing into a tubular film by forming bubbles, which burst between rollers after solidification. The film can then be cut, cut or converted (e.g., folded) as required. Traditional film production techniques can be used in this regard. If preferred blown film or cast film is a multilayer film, each layer is typically coextruded. The technician will know suitable extrusion conditions.

[0136] The film according to the present invention may be subjected to post-treatment processes such as surface modification, lamination or orientation processes, etc. Such orientation processes may be uniaxial (MDO) or biaxial orientation, wherein uniaxial orientation is preferred.

[0137] In another preferred embodiment, the film is non-oriented.

[0138] The resulting film can have any thickness conventional in the art. The thickness of the film is not important and depends on the end use. Therefore, the film can have, for example, 300 μm or less, typically 6 to 200 μm, preferably 10 to 180 μm, for example 20 to 150 μm or 20 to 120 μm. If desired, the polymer of the present invention can achieve a thickness of less than 100 μm, for example less than 50 μm. It is also possible to produce a film of the present invention with a thickness even less than 20 μm while maintaining good mechanical properties.

[0139] Furthermore, the present invention relates to the use of the film according to the invention as packaging material, in particular as packaging material for foods and / or medical products.

[0140] The films according to the invention have high stiffness (tensile modulus measured on 40 μm monolayer test blown films according to ISO 527-3), i.e. >300 MPa (in both directions) and / or dart impact resistance (measured on 40 μm monolayer test blown films according to ISO 7765-1:1988) and good tear resistance (determined on 40 μm monolayer test blown films according to ISO 6383-2).

[0141] Thus, the tensile modulus of the films according to the invention in the longitudinal as well as in the transverse direction (measured according to ISO 527-3 on 40 μm monolayer test blown films) ranges from 350 to 700 MPa, preferably from 400 to 650 MPa, more preferably from 450 to 600 MPa.

[0142] Furthermore, the film has a tear resistance in the longitudinal direction (determined according to ISO 6383-2 on a 40 μm monolayer test blown film) in the range of 14 to 50 N / mm, preferably 15 to 40 N / mm, even more preferably 15 to 35 N / mm, and a tear resistance in the transverse direction in the range of 70 to 200 N / mm, preferably 80 to 180 N / mm, more preferably 85 to 150 N / mm.

[0143] In one embodiment, the film according to the invention may further or additionally have a haze of less than 40%, preferably 5 to 35%, more preferably 10 to 30% (measured on 40 μm monolayer test blown film according to ASTM D 1003-00).

[0144] In another embodiment of the present invention, the membrane is according to formula (I):

[0145] The photomechanical ability (OMA) measured on a 40 μm test blown film is at least 2000 [MPa * g / %]

[0146] Up to 8000[MPa *g / %], preferably 2100[MPa * g / %] to up to 6500[MPa * g / %], more preferably 2200 [MPa * g / %] to up to 5500[MPa * g / %] range, wherein the tensile modulus in the longitudinal direction is measured according to ISO 527-3 at 23° C. on a 40 μm test blown film, the tear resistance in the transverse direction is determined according to ISO 6383-2 on a 40 μm test blown film, and the haze is measured according to ASTM D1003 on a 40 μm test blown film.

[0147] In view of the present invention, photomechanical ability (OMA) is understood as the ratio of mechanical properties, in particular tear resistance (TD) and tensile strength (TD), to optical properties, i.e. haze, wherein the mechanical properties aim to be as high as possible and the optical properties in terms of haze are desired to be as low as possible.

[0148] In another embodiment, the film has a dart drop impact strength (DDI) measured according to ISO 7765-1:1988 on a 40 μm single layer test blown film of 90 g to 400 g, preferably 100 g to 300 g, more preferably 110 g to 200 g.

[0149] In another embodiment, the film exhibits improved mechanical properties (higher stiffness and / or higher dart drop impact strength (DDI)) without deteriorating sealing properties, by following formula (III):

[0150] The tensile modulus (TM) in the longitudinal direction is measured at 23°C on a 40 μm test blown film according to ISO 527-3, DDI is the dart impact strength measured on a 40 μm test blown film according to ISO 7765-1:1988, and SIT is the seal initiation temperature measured on a 40 μm test blown film as described in the experimental part.

[0151] Preferably, the TM(MD) of this embodiment * DDI / SIT>400, more preferably>420.

[0152] TM(MD) of this embodiment * The suitable upper limit of DDI / SIT is 1,000, preferably 800, more preferably 700.

[0153] The present invention will be further described with reference to the following non-limiting examples.

[0154] Determination method:

[0155] Unless otherwise stated in the description or in the experimental section, the following methods were used to determine the properties of the polymers (including parts and components thereof) and / or any sample preparations thereof as described in the text or in the experimental section.

[0156] Melt flow rate:

[0157] The melt flow rate (MFR) is determined according to ISO 1133 and is expressed in g / 10 min. The MFR of polyethylene is determined at 190°C. The MFR can be determined at different loads, such as 2.16 kg (MFR2), 5 kg (MFR5) or 21.6 kg (MFR 21 ).

[0158] Calculation of MFR2 of component B and part (A-2)

[0159] logA=x·logB+(1-x)·logC

[0160]

[0161] For component B:

[0162] B = MFR2 of component (A)

[0163] C = MFR2 of component (B)

[0164] A = Final MFR2 of the multimodal polyethylene copolymer (P) (blend)

[0165] X = weight fraction of component (A)

[0166] For part (A-2):

[0167] B = MFR2 of the first part (A-1)

[0168] C = MFR2 of the second part (A-2)

[0169] A = Final MFR2 of the loop polymer (=component (A)) (mixture)

[0170] X = weight fraction of the first part (A-1)

[0171] density

[0172] The density of polymers is measured according to ISO 1183 Method A and is expressed in kg / m 3 Given, the sample preparation was carried out according to ISO 1872-2.

[0173] Comonomer content:

[0174] Quantification of microstructure by NMR spectroscopy

[0175] Quantitative nuclear magnetic resonance (NMR) spectroscopy was used to quantify the comonomer content of the polymers.

[0176] A Bruker Avance III 400 MHz NMR spectrometer was used to analyze the 1 H and 13 C was operated at 500.13 and 125.76 MHz and quantitative data were recorded in the molten state. 13 C{ 1 H}NMR spectra. All spectra were obtained using 13 The spectra were recorded at 150 °C using a C-optimized 7 mm magic angle spinning (MAS) probe head with nitrogen used for all pneumatics. Approximately 200 mg of material was loaded into a 7 mm outer diameter zirconium oxide MAS rotor and spun at 4 kHz. This setup was chosen primarily for the high sensitivity required for rapid identification and accurate quantification {klimke06, parkinson07, castignolles09}. Standard single pulse excitation was used, utilizing NOE {pollard04, klimke06} with a short recycle delay of 3 s and an RS-HEPT decoupling scheme {fillip05, griffin07}. A total of 1024 (1k) transients were acquired for each spectrum.

[0177] Quantitative 13 C{ 1 H} NMR spectra were processed, integrated, and the relevant quantitative properties were determined from the integration. All chemical shifts were internally referenced to the bulk methylene signal (δ+) at 30.00 ppm.

[0178] The amount of ethylene is quantified using the integration of the methylene (δ+) sites at 30.00 ppm and taking into account the number of reported sites per monomer:

[0179] E=I δ+ / 2

[0180] Correction for the presence of isolated comonomer units is based on the number of isolated comonomer units present:

[0181] E total = E + (3 * B+2 * H) / 2

[0182] where B and H are defined for their respective comonomers. Corrections are made in a similar manner when there is continuous and discontinuous comonomer incorporation.

[0183] Characteristic signals corresponding to the incorporation of 1-butene were observed and the comonomer fraction was calculated as the fraction of 1-butene in the polymer relative to all monomers in the polymer:

[0184] fB total = (B total / (E total + B total + H total)

[0185] Use 39.8ppm * The amount of isolated 1-butene incorporated into the EEBEE sequence was quantified by integrating the B2 sites and taking into account the number of reporter sites per comonomer:

[0186] B=I *B2

[0187] If present, the amount of continuously incorporated 1-butene in the EEBBEE sequence was quantified using the integration of the ααB2B2 site at 39.4 ppm and taking into account the number of reported sites for each comonomer:

[0188] BB=2 * IααB2B2

[0189] If present, the amount of non-continuous incorporation of 1-butene in the EEBEBEE sequence was quantified using the integration of the ββB2B2 site at 24.6 ppm and taking into account the number of reporting sites per comonomer:

[0190] BEB=2 * IββB2B2

[0191] Due to the isolated (EEBEE) and discontinuously incorporated (EEBEBEE) 1-butene * B2 and * The βB2B2 sites were overlapped separately and the total amount of isolated 1-butene incorporation was corrected based on the amount of discontinuous 1-butene present:

[0192] B=I *B2 -2 * I ββB2B2

[0193] No BBB sequence was observed. The total 1-butene content was calculated based on the sum of isolated, continuously and discontinuously incorporated 1-butene:

[0194] Total B = B + BB + BEB

[0195] The total mole fraction of 1-butene in the polymer is then calculated as:

[0196] fB=B total / (E total+B total+H total)

[0197] A characteristic signal corresponding to the incorporation of 1-hexene was observed and the comonomer fraction was calculated as the fraction of 1-hexene in the polymer relative to all monomers in the polymer:

[0198] fH total = H total / (E total + B total + H total)

[0199] Use 38.3ppm * The amount of isolated 1-hexene incorporated into the EEHEE sequence was quantified by integrating the B4 sites and taking into account the number of reporter sites per comonomer:

[0200] H=I *B4

[0201] If present, the amount of continuously incorporated 1-hexene in the EEHHEE sequence was quantified using the integration of the ααB4B4 site at 40.5 ppm and taking into account the number of reporter sites for each comonomer:

[0202] HH=2 * IααB4B4

[0203] If present, the amount of non-continuous incorporation of 1-hexene in the EEHEHEE sequence was quantified using the integration of the ββB4B4 site at 24.7 ppm and taking into account the number of reporter sites per comonomer:

[0204] HEH=2 * IββB4B4

[0205] No HHH sequence was observed. The total 1-hexene content was calculated based on the sum of isolated, continuous and discontinuously incorporated 1-hexene:

[0206] Total H = H + HH + HEH

[0207] The total mole fraction of 1-hexene in the polymer was then calculated as:

[0208] fH=H total / (E total+B total+H total)

[0209] The mole percentage of comonomer incorporation is calculated from the mole fraction:

[0210] B [mol%] = 100 * f

[0211] H [mol%] = 100 * f

[0212] The weight percent of comonomer incorporation is calculated from the mole fraction:

[0213] B [wt%] = 100 * (fB * 56.11) / ((fB * 56.11)+(fH * 84.16)+((1-

[0214] (fB+fH)) * 28.05))

[0215] H [wt%] = 100 * (fH * 84.16) / ((fB * 56.11)+(fH * 84.16)+((1 - (fB + fH)) * 28.05))

[0216] References:

[0217] Klimke, K., Parkinson, M., Piel, C., Kaminsky, W., Spiess, H.W., Wilhelm, M., Macromol. Chem. Phys. 2006; 207: 382.

[0218] Parkinson, M., Klimke, K., Spiess, H.W., Wilhelm, M., Macromol. Chem. Phys. 2007; 208: 2128.

[0219] Pollard, M., Klimke, K., Graf, R., Spiess, H.W., Wilhelm, M., Sperber, O., Piel, C., Kaminsky, W., Macromolecules 2004; 37: 813.

[0220] Filip, X., Tripon, C., Filip, C., J. Mag. Resn. 2005, 176, 239.

[0221] Griffin, J.M., Tripon, C., Samoson, A., Filip, C., and Brown, S.P., Mag. Res. in Chem. 2007 45, S1, S198.

[0222] Castignolles, P., Graf, R., Parkinson, M., Wilhelm, M., Gaborieau, M., Polymer 50(2009) 2373.

[0223] Busico, V., Cipullo, R., Prog. Polym. Sci. 26(2001) 443.

[0224] Busico,V.,Cipullo,R.,Monaco,G.,Vacatello,M.,Segre,AL,Macromoleucles30(1997)6251.

[0225] Zhou,Z.,Kuemmerle,R.,Qiu,X.,Redwine,D.,Cong,R.,Taha,A.,Baugh,D.Winniford,B.,J.Mag.Reson.187(2007)225.

[0226] Busico,V.,Carbonniere,P.,Cipullo,R.,Pellecchia,R.,Severn,J.,Talarico,G.,Macromol.Rapid Commun.2007,28,1128.

[0227] Resconi,L.,Cavallo,L.,Fait,A.,Pimontesi,F.,Chem.Rev.2000,100,1253.

[0228] Molecular weight, molecular weight distribution (M n 、M w , MWD):

[0229] The average molecular weight (M z 、M w and M n ), molecular weight distribution (MWD) and its breadth described by the polydispersity index PDI = Mw / Mn (where Mn is the number average molecular weight and Mw is the weight average molecular weight) are calculated by gel permeation chromatography (GPC) according to ASTM D 6474-12 using the following formula:

[0230]

[0231] For a constant elution volume interval ΔV i , where A i and M i and the elution volume V i The associated chromatographic peak slice area and the polyolefin molecular weight (MW), where N equals the number of data points obtained from the chromatogram between the integration limits.

[0232] A high temperature GPC instrument equipped with an infrared (IR) detector (IR4 or IR5 from PolymerChar (Valencia, Spain)) or a differential refractometer (RI) from Agilent Technologies, equipped with 3x Agilent-PLgel Olexis and 1x Agilent-PLgel Olexis Guard columns was used. 1,2,4-Trichlorobenzene (TCB) stabilized with 250 mg / L 2,6-di-tert-butyl-4-methylphenol was used as solvent and mobile phase. The chromatographic system was operated at a constant flow rate of 1 mL / min at 160°C. 200 μL of sample solution was injected for each analysis. Data collection was performed using Agilent Cirrus software version 3.3 or PolymerChar GPC-IR control software.

[0233] The column set was calibrated using universal calibration with 19 narrow MWD polystyrene (PS) standards ranging from 0.5 kg / mol to 11500 kg / mol. The PS standards were dissolved at room temperature for several hours. The conversion of polystyrene peak molecular weight to polyolefin molecular weight was accomplished by using the Mark Houwink equation and the following Mark Houwink constants:

[0234] K PS =19x 10 -3 mL / g, α PS =0.655

[0235] K PE =39x 10 -3 mL / g, α PE =0.725

[0236] A third-order polynomial fit was used to fit the calibration data.

[0237] For PE, all samples were prepared in the concentration range of 0.5–1 mg / ml and dissolved at 160 °C for 3 h with continuous gentle shaking.

[0238] Mw(Tp(LCF) / Mw(Tp(HCF) and the half-peak width (LCF) of the TREF curve for LogM>5,2

[0239] The chemical composition distribution at a certain elution temperature (polymer crystallinity in solution) as well as the determination of the molecular weight distribution and the corresponding molecular weight averages (Mn, Mw and Mv) were determined by fully automated cross-fractionation chromatography (CFC) as described in Ortin A., Monrabal B., Sancho-Tello J., Macromol. Symp., 2007, 257, 13-28.

[0240] Cross-fractionation chromatography (TREF xSEC) was performed using a CFC instrument (PolymerChar, Valencia, Spain). A four-band IR5 infrared detector (PolymerChar, Valencia, Spain) was used to monitor concentration. About 40 mg of polymer sample was dissolved in 25 ml of TCB for 150 min in a stainless steel container at 150 ° C. Once the sample was completely dissolved, an aliquot of 0.5 ml was loaded into a TREF column and stabilized at 110 ° C for 60 min. A constant cooling rate of 0.1 ° C / min was applied to reach a temperature of 30 ° C, so that the polymer was crystallized and precipitated. The following temperature steps were used for discontinuous elution process: (30, 40, 45, 50, 53, 56, 59, 62, 64, 66, 69, 72, 76, 79, 82, 85, 89, 91, 93, 95, 97, 100, 110 and 120).

[0241] In the second dimension, GPC analysis used 3PL Olexis columns and 1x Olexis Guard columns from Agilent (Church Stretton, UK) as stationary phases. 1,2,4-Trichlorobenzene (TCB, stabilized with 250 mg / L 2,6-di-tert-butyl-4-methylphenol) was applied as eluent at a constant flow rate of 1 mL / min at 150°C. The column set was calibrated using universal calibration (according to ISO 16014-2:2003) with at least 15 narrow MWD polystyrene (PS) standards ranging from 0.5 kg / mol to 11500 kg / mol. The following Mark Houwink constants were used to convert PS molecular weights to PE molecular weight equivalents.

[0242] K PS =19x 10 -3 mL / g, α PS =0.655

[0243] K PE =39x 10 -3 mL / g, α PP =0.725

[0244] A third order polynomial fit was used to fit the calibration data. Data processing was performed using software provided by PolymerChar and the CFC instrument.

[0245] In the first step, in order to obtain better separated TREF peaks of the high crystalline fraction (HCF) and the low crystalline fraction (LCF), an a-TREF curve considering only the high molecular weight fraction was created. Thus, the polymer fraction with a molar mass higher than log M of 5.2 (~158000 g / mol) is considered to obtain the TREF curve of the high molecular weight fraction (a-TREF (HMWF)). This is particularly advantageous if the comonomer content in the high crystalline fraction and the low crystalline fraction is similar, which means that the peak temperature difference between HCF and LCF is less than 20°C.

[0246] The peak maxima of the HCF peak (Tp(HCF)) and the LCF peak (Tp(LCF)) are determined from a-TREF(HMWF), where Tp(HCF) is higher than Tp(LCF) and less than 99° C. The a-TREF(HMWF) and a-TREF curves of CE2 are shown in FIG. 2 .

[0247] In the next step, the Mw at the elution temperatures Tp(LCF) and Tp(HCF) is determined. Thus, the Mw at Tp(LCF) (Mw(Tp(LCD))) is calculated by linear interpolation between the Mw values ​​measured by GPC for elution temperatures above Tp(LCF) and below Tp(LCF). This is achieved by using the "TREND" function in Excel.

[0248] The same procedure was performed to determine the Mw at Tp(HCF).

[0249] According to the Tp(LCF) of the obtained a-TREF(HMWF) curve, the half peak width is defined as the elution temperature difference between the front temperature and the rear temperature at half the maximum peak height of Tp(LCM). If the peaks are not well separated, the corresponding front temperature at half the maximum is taken from 35°C forward, and the rear temperature at half the maximum is taken from 100°C backward. If LCF is well separated from HCF, the rear temperature is taken after HCF.

[0250] Dart Drop Intensity (DDI)

[0251] DDI was measured according to ISO 7765-1:1988 / Method A on films (non-oriented films and laminates) produced as shown below. This test method covers the determination of the energy that will cause film failure under specified conditions of impact with a dart falling freely from a specified height, which will cause 50% of the test specimens to fail (Step Method A). A uniform increment of the missile mass was used during the test, and after each specimen test, the missile weight was reduced or increased by a uniform increment depending on the observed result (failure or no failure) of the specimen.

[0252] Standard conditions:

[0253] Adjustment time: >96h at 50±2℃±10%rh

[0254] Test temperature: 23℃

[0255] Dart head material: phenolic resin

[0256] Dart diameter: 38mm

[0257] Drop height: 660mm

[0258] Result: Impact failure weight -50% [g]

[0259] Tensile modulus

[0260] The tensile tests were carried out according to ISO 527-3, and in addition the modulus of elasticity (secant modulus between 0.05% and 0.25% elongation) was determined. Type 2 (parallel-sided specimens) specimens were used.

[0261] During the test, the specimen is extended along its long axis and the tensile properties are determined at a constant test speed (crosshead speed) until the specimen breaks. During this procedure, the load borne by the specimen and the elongation measured by the crosshead are measured.

[0262] Standard conditions:

[0263] Adjustment time: >96h at 50±2℃±10%rh

[0264] Test temperature: 23℃

[0265] Clamping distance: 100mm

[0266] Gauge length: 100mm

[0267] Secant modulus: 0.05%-0.25%

[0268] Test speed modulus: 1mm / min

[0269] Test speed: 200mm / min

[0270] Haze

[0271] Haze is measured according to ASTM D1003 test method (Method A - Hazemeter). This method covers the evaluation of specific light transmission and scattering properties of planar portions of materials, such as substantially transparent plastics.

[0272] The beam strikes the specimen and enters an integrating sphere. The interior of the sphere is uniformly coated with a matte white material to allow for diffusion. The detector in the sphere measures total transmittance, haze, and clarity (not part of ASTM D1003).

[0273] The incident light will be diffusely transmitted, changing the apparent quality of the product. This may be the result of scattering from the surface structure (roughness) or from within the particles, such as air inclusions, poorly dispersed pigments, dust inclusions or crystallization. As the roughness increases, the haze increases and the transmittance of the plastic decreases.

[0274] Standard conditions:

[0275] Adjustment time: >96h

[0276] Temperature: 23℃

[0277] Test Procedure: A-Haze Meter

[0278] Tear resistance (determined as Elmendorf tear (N) in machine direction (MD) and transverse direction (TD)):

[0279] Tear resistance is measured according to ISO 6383-2 method. The force required to propagate a tear on a film sample is measured using a pendulum device and a constant radius specimen is used. The pendulum swings along an arc under the action of gravity, tearing the sample from the pre-cut slit. One side of the specimen is fixed by the pendulum and the other side is fixed by a fixed fixture.

[0280] The tear resistance is the force required to tear the sample. The relative tear resistance (N / mm) is then calculated by dividing the tear resistance by the thickness of the film.

[0281] Sealing start temperature (SIT); Sealing end temperature (SET), Sealing range

[0282] This method determines the sealing temperature range (sealing range) of polyethylene films, in particular blown films or cast films. The sealing temperature range is the temperature range over which the film can be sealed according to the conditions given below.

[0283] The lower limit (heat seal initiation temperature (SIT)) is the sealing temperature at which a seal strength of ≥ 5 N is achieved. The upper limit (seal end temperature (SET)) is reached when the film sticks to the sealing device.

[0284] The measurements were performed according to a slightly modified ASTM F1921-12, where the test parameters sealing pressure, cooling time and test speed were modified. The force / temperature curve was continued until thermal failure of the film. The sealing range was determined on a 40 μm thick single-layer test blown film on a J&B Universal Sealer Model 4000, where the following additional parameters were used:

[0285] Adjustment time: >96h

[0286] Sample width: 25mm

[0287] Sealing pressure: 0.4N / mm 2 (PE)

[0288] Sealing time: 1 second

[0289] Delay time: 30 seconds

[0290] Sealing jaws size: 50x5 mm

[0291] Sealing jaws shape: flat

[0292] Sealing jaw coating: Niptef

[0293] Sealing temperature: ambient temperature -240℃

[0294] Sealing temperature interval: 5°C

[0295] Starting temperature: 50°C Clamp separation rate: 42 mm / s

[0296] Membrane sample preparation

[0297] A Collin 25 lab scale line was used to prepare 40 μm thick monolayer test films consisting of the multimodal polymer (P) of the invention and the corresponding comparative polymer. The film samples were produced with BUR 2.5:1. The melt temperature was 199°C, the frost line distance was 100 mm, the screw speed was 126 rpm and the discharge speed was 7.3 m / min.

[0298] Experimental Section

[0299] Cat. Example: Catalyst Preparation of IE1 (CAT1)

[0300] SiO2 loading:

[0301] 10 kg of silica (PQ Corporation ES757, calcined at 600°C) was added from a feed bucket and inerted in the reactor until the O2 level reached less than 2 ppm.

[0302] Preparation of MAO / tol / MC:

[0303] At 25°C (oil circulation temperature) and 95rpm stirring, a 30wt% MAO toluene solution (14.1kg) was added from a balance to another reactor, followed by toluene (4.0kg). After adding toluene, the stirring speed was increased from 95rpm to>200rpm, with a stirring time of 30 minutes. Metallocene racemic-dimethylsilanediylbis{2-(5-(trimethylsilyl)furan-2-yl)-4,5-dimethylcyclopentadiene-1-yl}zirconium dichloride 477g was added from a metal cylinder, followed by 4kg toluene rinse (total toluene was 8.0kg). The reactor stirring speed was changed to 95rpm for MC feeding, returned to 200rpm and continued for 3h reaction time. After the reaction time, the MAO / tol / MC solution was transferred to a feed container.

[0304] Preparation of catalyst:

[0305] The reactor temperature was set to 10°C (oil circulation temperature) and stirring was adjusted to 40 rpm during the addition of MAO / tol / MC. MAO / tol / MC solution (22.2 kg) was added over 205 min, followed by a stirring time of 60 min (oil circulation temperature set to 25°C). After stirring, the "dry mix" was stabilized at 25°C (oil circulation temperature) for 12 h with a stirring speed of 0 rpm. The reactor was rotated 20° (back and forth) and stirred several times per hour at a speed of 5 rpm.

[0306] After stabilization, the catalyst was dried at 60°C (oil circulation temperature) for 2 h under a 2 kg / h nitrogen flow, followed by drying under vacuum for 13 h (same nitrogen flow rate, stirring at 5 rpm). The dried catalyst was sampled and the HC content was measured using a Sartorius moisture analyzer (model MA45) in a glove box using thermogravimetry. The target HC level was <2% (actual 1.3%).

[0307] Comparative Example Catalyst (CAT2)

[0308] As catalyst CAT2, an aluminoxane-containing supported catalyst was used, which contained the metallocene bis(1-methyl-3-n-butylcyclopentadienyl)zirconium(IV) chloride and a reinforced Activator technology.

[0309] Polymerization: Inventive Example: Inventive multimodal polyethylene polymer (P) with 1-butene and 1-hexene comonomers

[0310] The Borstar pilot plant had a three-reactor set-up (Loop 1 - Loop 2 - GPR1) and a prepolymerization loop reactor.

[0311] The inventive multimodal polymers (P) of Example 1 (IE1) and Example 2 (IE2) as well as the multimodal polymer (P) of Comparative Example (CE1) were produced by using the polymerisation conditions given in Table 1.

[0312] Table 1: Polymerization conditions

[0313]

[0314]

[0315] The polymer was mixed with 2400 ppm of Irganox B561 (supplied by BASF) and 270 ppm of Dynamar FX 5922 (supplied by 3M) and extruded into pellets using a twin-screw extruder ZSK18 under a nitrogen atmosphere; the melt temperature was 192°C.

[0316] Table 2: Material properties and film parameters of the multimodal polymers of the invention (P) and comparative copolymers

[0317]

[0318]

[0319] *:HCF: High Crystalline Fraction / LCF: Low Crystalline Fraction. CFC data.

[0320] As can be clearly seen from the above table, the films consisting of the multimodal polymer (P) according to the invention show higher tear resistance and tensile modulus compared to the comparative example.

[0321] Furthermore, such films have improved overall properties, ie higher OMA.

[0322] Furthermore, the films of the present invention show an optimal balance between stiffness, impact resistance and sealing properties.

Claims

1. A metallocene-catalyzed multimodal polyethylene polymer (P) consisting of: (i) 35.0 to 50.0 wt% of a polyethylene component (A), based on the multimodal polyethylene polymer (P), and (ii) 50.0 to 65.0 wt% of a polyethylene component (B), based on the multimodal polyethylene polymer (P), wherein the polyethylene component (A) has 952 to 970 kg / m 3 Density in the range (ISO 1183), an MFR2 (190°C, 2.16 kg, ISO 1133) in the range of 1.0 to 15.0 g / 10 min, a 1-butene content (in terms of 13 C{ 1 H}NMR determination), and The polyethylene component (A) is composed of an ethylene polymer portion (A-1) and an ethylene polymer portion (A-2), wherein the ethylene polymer portion (A-1) has 945 to 965 kg / m 3 range and MFR2 (190°C, 2.16kg, ISO 1133) in the range of 0.5 to 8.0 g / 10min, and The ethylene polymer portion (A-2) has a carbon content of 950 to 970 kg / m 3 The density and MFR2 (190°C, 2.16kg, ISO 1133) in the range of 1.0 to 15.0 g / 10min; the polyethylene component (B) has 900 to 940 kg / m 3 Density in the range (ISO 1183), An MFR2 (190°C, 2.16 kg, ISO 1133) in the range of 0.01 to 2.0 g / 10 min, a 1-hexene content (using 13 C{ 1 H}NMR determination); wherein the multimodal polyethylene polymer (P) has 927 to 950 kg / m 3 Density in the range (ISO 1183), MFR2 (190°C, 2.16 kg, ISO 1133) in the range of 0.1 to 3.0 g / 10 min, molecular weight distribution (Mw / Mn) determined by GPC in the range of 4.6 to at most 7.0 and the ratio of the molecular weight (Mw) of the low crystalline fraction (LCF) to the molecular weight (Mw) of the high crystalline fraction (HCF) determined as described in the experimental part Mw(Tp(LCF) / Mw(Tp(HCF)) in the range of 0.8 to 4.

0.

2. The metallocene-catalyzed multimodal polyethylene polymer (P) according to claim 1, wherein polymer (P) has a half-peak width of the low crystalline part (LCF) in the TREF curve for LogM>5.2 determined as described in the experimental part in the range of 2.0 to 15.

0.

3. The metallocene-catalyzed multimodal polyethylene polymer (P) according to claim 1 or 2, wherein the ethylene polymer portion (A-1) has a molecular weight of 948 to 962 kg / m 3 , preferably 950 to 960 kg / m 3 range (ISO 1183) and an MFR2 (190°C, 2.16 kg, ISO 1133) in the range of 0.6 to 7.5, preferably 0.8 to 7.0 g / 10 min, and The ethylene polymer portion (A-2) has a molecular weight of 955 to 965 kg / m 3 The density (ISO 1183) in the range of 1.5 to 12.0 g / 10 min, preferably 2.0 to 10.0 g / 10 min, MFR2 (190°C, 2.16kg, ISO 1133).

4. The metallocene-catalyzed multimodal polymer (P) according to any one of the preceding claims, wherein the ethylene polymer component (A) has an MFR2 (190°C, 2.16 kg, ISO 1133) in the range of 1.5 to 10.0 g / 10 min, preferably 2.0 to 8.0 g / 10 min, more preferably 2.5 to 7.0 g / 10 min, and The MFR2 (190°C, 2.16 kg, ISO 1133) of the ethylene polymer component (B) is from 0.03 to 1.6 g / 10 min, preferably from 0.05 to 1.2 g / 10 min, even more preferably from 0.06 to 1.0 g / 10 min or wherein the MFR of the multimodal polymer (P) is 21 The MFR / MFR2 ratio is in the range of 20.0 to 40.0, preferably 22.0 to 35.0, more preferably 24.0 to 32.

0.

5. The metallocene-catalyzed multimodal polymer (P) according to any one of the preceding claims, wherein the total amount of 1-butene based on the multimodal polymer (P) is in the range of 0.01 to 0.1 mol%, preferably 0.02 to 0.08 mol%, more preferably 0.02 to 0.06 mol%, and The total amount of 1-hexene based on the multimodal polymer (P) is between 0.1 and 3.0 mol%, preferably between 0.2 and 2.0 mol%, More preferably, it is in the range of 0.3 to 1.2 mol%.

6. The metallocene-catalyzed multimodal polymer (P) according to any one of the preceding claims, wherein the total amount of 1-butene present in the polyethylene component (A) is in the range of 0.02 to 0.15 mol%, preferably 0.03 to 0.10 mol%, based on the polyethylene component (A), and The total amount of 1-hexene present in the polyethylene component (B) is in the range of 0.3 to 3.0 mol%, more preferably 0.4 to 2.0 mol%, based on the polyethylene component (B).

7. The metallocene-catalyzed multimodal polymer (P) according to any one of the preceding claims, wherein the multimodal polymer (P) is produced in the presence of a metallocene complex of formula (II): Wherein each X is independently a halogen atom, C 1-6 -alkyl, C 1-6 - alkoxy, phenyl or benzyl; Each Het is independently a monocyclic heteroaromatic group containing at least one heteroatom selected from O or S; L is -R'2Si-, wherein each R' is independently a C substituted with an alkoxy group having 1 to 10 carbon atoms. 1-20 -Hydrocarbon or C 1-10 -alkyl; M is Ti, Zr or Hf; Each R1 is the same or different, is C 1-6 -alkyl or C 1-6 - alkoxy; Each n is 1 to 2; Each R2 is the same or different, and is C 1-6 -alkyl, C 1-6 -alkoxy or -Si(R)3 group; Each R is optionally replaced by 1 to 3 C 1-6 -alkyl substituted C 1-10 - alkyl or phenyl; and Each p is from 0 to 1.

8. A membrane comprising the metallocene-catalyzed multimodal polymer (P) according to any one of the preceding claims 1 to 7.

9. The film according to claim 8, wherein the film comprises at least one layer comprising a metallocene-catalyzed multimodal polymer (P), wherein The at least one layer comprises at least 50 wt%, more preferably at least 60 wt%, even more preferably at least 70 wt%, yet more preferably at least 80 wt% of the metallocene-catalyzed multimodal polymer (P) according to any one of the preceding claims 1 to 7.

10. The film according to any one of the preceding claims 8 to 9, wherein the film is characterized by a tensile modulus in the longitudinal and transverse directions (measured according to ISO 527-3 on a 40 μm single-layer test blown film) in the range of 350 MPa to 700 MPa, preferably 400 MPa to 650 MPa, more preferably 450 MPa to 600 MPa.

11. The film according to any one of the preceding claims 8 to 10, wherein the film is characterized by a tear resistance in the longitudinal direction (determined according to ISO 6383-2 on a 40 μm monolayer test blown film) in the range of 14 to 50 N / mm, preferably 15 to 40 N / mm, more preferably 15 to 35 N / mm and a tear resistance in the transverse direction in the range of 70 to 200 N / mm, preferably 80 to 180 N / mm, more preferably 85 to 150 N / mm.

12. The film according to any one of the preceding claims 8 to 11, wherein the film is characterized by a haze of less than 40%, preferably from 5% to 35%, more preferably from 10% to 30% (measured on a 40 μm single layer test blown film according to ASTM D 1003-00).

13. The film according to any one of the preceding claims 8 to 12, wherein the film is characterized in that the film is according to formula (I): The photomechanical ability (OMA) measured on a 40 μm test blown film is at least 2000 [MPa * g / %] to up to 8000[MPa * g / %], preferably 2100[MPa * g / %] to up to 6500[MPa * g / %], more preferably 2200 [MPa * g / %] to up to 5500[MPa * g / %] range, wherein the tensile modulus in the longitudinal direction is measured according to ISO 527-3 at 23° C. on a 40 μm test blown film, the tear resistance in the transverse direction is determined according to ISO 6383-2 on a 40 μm test blown film, and the haze is measured according to ASTM D1003 on a 40 μm test blown film.

14. The membrane according to any one of the preceding claims 8 to 13, wherein the membrane is characterized by formula (III): Relationship between mechanical properties and sealing properties determined on 40 μm test blown films, wherein the tensile modulus in the longitudinal direction is measured on 40 μm test blown films at 23°C according to ISO 527-3, DDI is the dart drop impact strength determined on 40 μm test blown films according to ISO 7765-1:1988, and SIT is the seal initiation temperature measured on 40 μm test blown films as described in the experimental part.

15. Use of the film according to any one of the preceding claims 8 to 14 as packaging material, in particular as packaging material for food and / or medical products.

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