Polyethylene composition with improved processability

Abstract

The present invention relates to a metallocene catalysed multimodal polyethylene copolymer (P), the use of the multimodal copolymer of ethylene (P) in film applications and a film comprising the polymer composition of the invention.

Description

Technical Field

[0001] This invention relates to metallocene-catalyzed multimodal polyethylene copolymers (P) with improved processing performance, the use of multimodal polyethylene copolymers (P) in membrane applications, and membranes comprising the polymer compositions of this invention. Background Technology

[0002] Single-peak polyethylene (PE) polymers, such as SSC products, are typically used in membrane applications. Single-peak PE polymers possess, for example, good optical properties (such as low haze); however, from a production perspective, the melt processing of such polymers is unsatisfactory and can lead to quality issues in the final product. Multi-peak PE polymers with two or more different polymer components are easier to process, but melt homogenization of multi-peak PEs can be problematic, resulting in non-uniform final products, as evidenced by, for example, the high gel content of the final product.

[0003] Due to its excellent cost-effectiveness, state-of-the-art mLLDPE (metallocene-catalyzed linear low-density polyethylene) is widely used in everyday life, such as in packaging. One significant drawback is its narrow molecular weight distribution, resulting in low shear thinning, which leads to membrane conversion problems, thus limiting production capacity.

[0004] The goal is to increase output in membrane production because it is economically advantageous, as more product can be produced per unit time, and it is also advantageous from a CO2 footprint perspective. Therefore, any increase in output must be achieved without compromising membrane performance.

[0005] Increasing the melt flow rate (MFR2) of the polymer resin can reduce the melt temperature and melt pressure during blown film production. This is expected to increase the yield of the blown film process. On the other hand, an increased MFR generally has a negative impact on bubble stability; therefore, a film resin with a low MFR2 is preferred for good bubble stability during the blown film process. A lower MFR2 value is also advantageous given toughness.

[0006] Therefore, a trade-off needs to be struck between higher MFR and increased production, as well as poor processing performance due to poor bubble stability.

[0007] Therefore, the inventors sought to maximize the processing performance of mLLDPE resin, enabling higher yields, particularly in blown film processes, while maintaining the strength and stability of the bubbles. Needless to say, any control over polymer properties to increase yield should not compromise the performance of the final film, such as in terms of mechanical strength, optical properties, and sealing performance.

[0008] The inventors have now discovered that metallocene-catalyzed multimodal polyethylene copolymers (P) with specific polymer designs, prepared using specific metallocene catalysts, exhibit improved processing properties, particularly evident in higher traction speeds.

[0009] Such metallocene-catalyzed multimodal polyethylene copolymers (P) exhibit improved rheological behavior, particularly in terms of shear thinning index.

[0010] Membranes made from such metallocene-catalyzed multimodal polyethylene copolymers (P) also have an improved balance of performance, particularly considering the lower seal initiation temperature (SIT), higher stiffness (i.e., tensile modulus), and good impact strength (i.e., dart impact, DDI). Summary of the Invention

[0011] Therefore, the present invention relates to a metallocene-catalyzed multimodal polyethylene copolymer (P) of ethylene and at least two different comonomers selected from α-olefins having 4 to 10 carbon atoms, comprising the following composition

[0012] (i) 30.0 to 70.0 wt% of ethylene polymer component (A), and

[0013] (ii) 70.0 to 30.0 wt% of ethylene polymer component (B),

[0014] The ethylene polymer component (A) has

[0015] 920 to 950 kg / m 3 Density within the range and MFR2 (190℃, 2.16kg, ISO 1133) within the range of 1.0 to 20.0 g / 10min; and

[0016] The ethylene polymer component (A) consists of an ethylene polymer portion (A-1) and an ethylene polymer portion (A-2).

[0017] The ethylene polymer portions (A-1) and (A-2) have a strength of 920 to 960 kg / m³. 3 Preferably, the concentration is 0.5 to 100.0 g / m³. 3 Density within the range, and MFR2 (190℃, 2.16kg, ISO 1133) within the range of 0.5 to 100.0 g / 10min.

[0018] The MFR2 of the ethylene polymer portions (A-1) and (A-2) are different from each other, and

[0019] The density of polymer portion (A-2) can be the same as or different from that of polymer portion (A-1).

[0020] and

[0021] The ethylene polymer component (B) has

[0022] 890 to 915 kg / m 3 Density within the range and MFR2 (190℃, 2.16kg, ISO 1133) within the range of 0.01 to 1.5 g / 10 min; and

[0023] Among them, multimodal polyethylene copolymer (P) has

[0024] a) Between 910 and 940 kg / m 3 Density within a certain range

[0025] b) MFR2 (190℃, 2.16kg, ISO 1133) in the range of 0.1 to 10.0 g / 10 min.

[0026] c) MFR in the range of greater than 20 to 50 21 The ratio of (190℃, 21.6kg, ISO 1133) to MFR2 (190℃, 2.16kg, ISO 1133) (MFR 21 / MFR2),

[0027] d) is defined as 10 5 / Gc is the rheological polydispersity index, where Gc is the cross modulus of dynamic rheology at 190 °C according to ISO 6271-10, ranging from greater than 0.57 to 2.0 Pa. -1 ,and

[0028] e) Shear thinning index SHI in the range of greater than 1.80 to 10.0 0 / 50 The measurements were as described in the experimental section.

[0029] In another embodiment of the invention, the metallocene-catalyzed multimodal polyethylene copolymer (P) is prepared in the presence of a metallocene of formula (I):

[0030]

[0031] Each X is independently a halogen atom, C 1-6 -alkyl, C 1-6 -alkoxy, phenyl, or benzyl;

[0032] Each Het is independently a monocyclic heteroaromatic group containing at least one heteroatom selected from O or S;

[0033] L is -R'2Si-, where each R' is independently a C substituted with an alkoxy group having 1 to 10 carbon atoms. 1-20- Hydrocarbon group or C 1-10 -alkyl;

[0034] M is Ti, Zr, or Hf;

[0035] Each R 1 Same or different, is C 1-6 -alkyl or C 1-6 -alkoxy group;

[0036] Each n is between 1 and 2;

[0037] Each R 2 Same or different, is C 1-6 -alkyl, C 1-6 -alkoxy or -Si(R)3 group;

[0038] Each R is arbitrarily selected by 1 to 3 Cs. 1-6 -alkyl-substituted C 1-10 -alkyl or phenyl; and

[0039] Each p is between 0 and 1.

[0040] Surprisingly, this metallocene-catalyzed multimodal polyethylene copolymer (P) exhibits improved processing properties compared to other multimodal polyethylene copolymers with comparable MFR2 values.

[0041] Therefore, this can reduce melt pressure and temperature during the blown film process, thereby increasing yield / higher traction speed while maintaining stable process conditions (i.e., stable / robust bubbles).

[0042] Furthermore, the multimodal polyethylene copolymer (P) of the present invention provides the film with improved sealing performance, such as a lower seal initiation temperature (SIT), and good mechanical properties, such as high dart strength (DDI) and good tensile modulus.

[0043] Therefore, in another embodiment, the present invention further relates to the use of the metallocene-catalyzed multimodal polyethylene copolymer (P) as defined above for the production of blown films, and to blown films made from such metallocene-catalyzed multimodal polyethylene copolymer (P).

[0044] Therefore, the present invention further relates to a membrane comprising at least one layer of a multimodal polyethylene copolymer (P) containing a metallocene catalyst.

[0045] The membrane is characterized by a sealing initiation temperature (SIT) of less than 97°C, preferably in the range of 60 to 96°C, and more preferably in the range of 70 to 95°C, as described in the experimental section on a 40 μm monolayer test blown film.

[0046] definition

[0047] When the term "comprising / including" is used in this specification and claims, it does not exclude other unspecified elements of primary or secondary functional importance. For the purposes of this invention, the term "consisting of..." is considered a preferred embodiment of the term "comprising / including". If a group is defined below as including at least a certain number of embodiments, this should also be understood as a disclosed group, which preferably consists only of these embodiments.

[0048] Whenever the terms “including” or “having” are used, these terms mean equivalent to “include / comprise” as defined above.

[0049] When referring to a singular noun, use the indefinite or definite article, such as "a", "an", or "the / that", unless otherwise specified, this includes the plural form of the noun.

[0050] In this invention, a metallocene-catalyzed multimodal copolymer is defined as a multimodal copolymer (P) of ethylene with at least two different comonomers selected from α-olefins having 4-10 carbon atoms, produced in the presence of a metallocene catalyst.

[0051] In the context of multimodal polyethylene copolymers (P), the term "multimodal" herein refers to multimodality in relation to the melt flow rate (MFR) of ethylene polymer components (A) and (B) and optionally ethylene polymer portions (A-1) and (A-2), i.e., ethylene polymer components (A) and (B) and portions (A-1) and (A-2) have different MFR values. As described below, multimodal polyethylene copolymers (P) may further possess multimodality in relation to one or more other properties between ethylene polymer components (A) and (B) and between portions (A-1) and (A-2).

[0052] The multimodal polyethylene copolymer (P) of the present invention as defined above, below or in the claims is also referred to herein simply as "multimodal PE" or "multimodal copolymer (P)".

[0053] The term rheological polydispersity index used in this article refers to 10. 5 The value of / Gc, where Gc represents the cross modulus. The cross modulus is a rheological parameter defined according to the experimental section. Therefore, the rheological polydispersity index here is a rheological measurement, which differs from the Mw / Mn measured by GPC.

[0054] The following preferred embodiments, properties, and subgroups of multimodal PE and its ethylene polymer components (A) and (B), as well as its ethylene polymer portions (A-1) and (A-2), and the membranes of the present invention including the preferred range, are independently generalizable such that they can be used in any order or combination to further define the preferred embodiments of the multimodal PE and articles of the present invention.

[0055] Multimodal PE as well as ethylene polymer components (A) and (B) and ethylene polymer fractions (A-1) and (A-2)

[0056] The metallocene-catalyzed multimodal polyethylene copolymer (P) is referred to as "multimodal" in this paper because the ethylene polymer component (A) and the ethylene polymer component (B) have been produced under different polymerization conditions, resulting in different melt flow rates (MFR, e.g., MFR2). That is, multimodal PE is multimodal at least with respect to the difference in MFR between the ethylene polymer components (A) and (B).

[0057] The metallocene-catalyzed multimodal copolymer (P) consists of (i) 30.0 to 70.0 wt% of an ethylene polymer component (A) and (ii) 70.0 to 30.0 wt% of an ethylene polymer component (B).

[0058] The total amount of (A) and (B) is 100.0 wt%.

[0059] The ethylene polymer component (A) consists of ethylene polymer portions (A-1) and (A-2).

[0060] The MFR2 of the ethylene polymer portions (A-1) and (A-2) may be the same or different from each other. Preferably, the MFR2 of the ethylene polymer portions (A-1) and (A-2) are different from each other, and more preferably, the ethylene polymer portion (A-2) has a higher MFR2 than the ethylene polymer portion (A-1).

[0061] Therefore, the MFR2 (190°C, 2.16 kg, ISO 1133) of the ethylene polymer portions (A-1) and (A-2) is in the range of 0.5 to 100 g / 10 min, preferably 1.0 to 50.0 g / 10 min, more preferably 1.5 to 30.0 g / 10 min, even more preferably 2.0 to 15.0 g / 10 min, and still more preferably 2.5 to 10.0 g / 10 min.

[0062] The MFR2 of ethylene polymer components (A) and (B) are different from each other.

[0063] The MFR2 (190°C, 2.16 kg, ISO 1133) of the ethylene polymer component (A) is in the range of 1.0 to 20 g / 10 min, preferably 2.0 to 15 g / 10 min, more preferably 3.0 to 10 g / 10 min, and even more preferably 4.0 to 8.0 g / 10 min.

[0064] The MFR2 (190°C, 2.16 kg, ISO 1133) of the ethylene polymer component (B) is in the range of 0.01 to 1.5 g / 10 min, preferably 0.1 to 1.2 g / 10 min, more preferably 0.2 to 1.0 g / 10 min, and even more preferably 0.3 to 1.0 g / 10 min.

[0065] The MFR2 (190°C, 2.16 kg, ISO 1133) of the multimodal copolymer (P) is in the range of 0.1 to 10.0 g / 10 min, preferably 0.3 to 8.0 g / 10 min, more preferably 0.5 to 5.0 g / 10 min, and even more preferably 1.0 to 3.0 g / 10 min.

[0066] MFR of multimodal copolymer (P) 21 The ratio of (190℃, 21.6kg, ISO 1133) to MFR2 (190℃, 2.16kg, ISO 1133) (MFR 21 / MFR2) is in the range of greater than 20 to 50, preferably 21 to 40, and more preferably 25 to 35.

[0067] In another embodiment, the ratio of the MFR2 (190°C, 2.16 kg, ISO 1133) of the ethylene polymer component (A) to the MFR2 (190°C, 2.16 kg, ISO 1133) of the final multimodal copolymer (P) can be 1.5 to less than 5.1, preferably 2.3 to 5.0, more preferably 2.5 to 4.5, and even more preferably 2.8 to 4.0.

[0068] Naturally, in addition to the multimodality of MFR2 (i.e., the difference between them) of the ethylene polymer components (A) and (B) and optionally the multimodality of MFR2 (i.e., the difference between them) of the portions (A-1) and (A-2), the multimodal PE of the present invention may also be multimodal with respect to, for example, one or both of two other properties:

[0069] Multimodality in terms of the differences between the following:

[0070] - The content and / or type of comonomers present in ethylene polymer components (A) and (B); and / or

[0071] -Density of ethylene polymer components (A) and (B).

[0072] Preferably, the multimodal copolymer (P) is further multimodal in terms of comonomer type and / or comonomer content (wt%), more preferably wherein the α-olefin comonomer having 4-10 carbon atoms in the ethylene polymer component (A) is different from the α-olefin comonomer having 4-10 carbon atoms in the ethylene polymer component (B), even more preferably wherein the α-olefin comonomer having 4-10 carbon atoms in the ethylene polymer component (A) is 1-butene, and the α-olefin comonomer having 4-10 carbon atoms in the ethylene polymer component (B) is 1-hexene. The polymer portions (A-1) and (A-2) have the same comonomer type, therefore the same α-olefin comonomer having 4-10 carbon atoms is used in portions (A-1) and (A-2), therefore more preferably both portions have 1-butene as a comonomer.

[0073] The comonomer content of components (A) and (B) can be measured, or, in a preferred case, one component is first produced, and then another component is produced in a so-called multi-stage process in the presence of the first-produced component. The comonomer content of the first-produced component (e.g., component (A)) can then be measured, and the comonomer content of the other component (e.g., component (B)) can be calculated according to the following formula:

[0074] Comonomer content in component B (mol%) = (Comonomer content in the final product (mol%) - (Weight fraction of component A * Comonomer content in component A (mol%)) / (Weight fraction of component B)

[0075] Based on the multimodal polymer (P), the total amount of 1-butene preferably ranges from 0.1 to 1.5 wt%, more preferably from 0.2 to 1.2 wt%, and even more preferably from 0.3 to 1.0 wt%.

[0076] Based on the multimodal polymer (P), the total amount of 1-hexene is preferably in the range of 2.0 to 20.0 wt%, more preferably 4.0 to 15.0 wt%, and more preferably 5.0 to 12.0 wt%.

[0077] Based on the ethylene-1-butene polymer component (A), the total amount (wt%) of 1-butene present in the ethylene polymer component (A) is 0.5 to 5.0 wt%, preferably 0.8 to 4.0 wt%, more preferably 1.0 to 3.0 wt%, and even more preferably 1.0 to 2.5 wt%.

[0078] Based on the ethylene-1-hexene polymer component (B), the total amount (wt%) of 1-hexene present in the ethylene polymer component (B) is 8.0 to 25.0 wt%, preferably 10.0 to 22.0 wt%, more preferably 12.0 to 20.0 wt%.

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

[0080] The density range of the ethylene polymer component (A) is 920 to 950 kg / m³. 3 Preferred weight is 925 to 950 kg / m³. 3 More preferably, it is 930 to 945 kg / m 3 The density range of the ethylene polymer component (B) is 890 to 915 kg / m³. 3 More preferably, it is 895 to 910 kg / m 3 .

[0081] The density of the polymer portion (A-1) is between 920 and 960 kg / m³. 3 Preferred weight is 925 to 955 kg / m³. 3 More preferably 930 to 950 kg / m 3 Within the range, for example, 935 to 945 kg / m 3 .

[0082] The density of polymer portion (A-2) can be the same as or different from the density of polymer portion (A-1).

[0083] Therefore, the density of the polymer portion (A-2) is between 920 and 960 kg / m³. 3 Preferred weight is 925 to 955 kg / m³. 3 More preferably 930 to 950 kg / m 3 Within the range, for example, 935 to 945 kg / m 3 .

[0084] Metallocene-catalyzed multimodal copolymers (P) are preferably linear low-density polyethylene (LLDPE), which has well-known implications.

[0085] The density of the multimodal copolymer (P) is between 910 and 940 kg / m³. 3 Preferred weight is 912.0 to 935 kg / m³. 3 More preferably 915.0 to 930.0 kg / m 3 Even better, 916 to 928 kg / m 3 Within the range, 918 to 925 kg / m³ is still preferred. 3 Within the range.

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

[0087] Within the scope of this invention, the first and second ethylene polymer portions (A-1 and A-2) of the ethylene polymer component (A) are present in a weight ratio of 4:1 to up to 1:4, for example, 3:1 to 1:3, or 2:1 to 1:2, or 1:1.

[0088] Based on the multimodal polymer (P), the ethylene polymer component (A) is present in an amount of 30.0 to 70.0 wt%, preferably in an amount of 32.0 to 55.0 wt%, and even more preferably in an amount of 34.0 to 45.0 wt%.

[0089] Therefore, based on the multimodal copolymer (P), the ethylene polymer component (B) is present in an amount of 70.0 to 30.0 wt%, preferably in an amount of 68.0 to 45.0 wt%, and more preferably in an amount of 66.0 to 55.0 wt%.

[0090] The metallocene-catalyzed multimodal copolymers (P) according to the present invention have improved rheological properties, which leads to improved processing performance without any adverse effects on other polymer properties.

[0091] Therefore, the metallocene-catalyzed multimodal copolymer (P) is further characterized by being defined as 10 5 The rheological polydispersity index / Gc (Gc is the cross modulus of dynamic rheology at 190℃ according to ISO 6271-10 standard) is greater than 0.57 to 2.0 Pa. -1 Within the range of 0.60 to 1.5 Pa, the preferred value is 0.60 to 1.5 Pa. -1 Within the range, more preferably 0.62 to 1.2 Pa. -1 Within the range, and

[0092] The shear thinning index SHI was measured as described in the experimental section. 0 / 50 It is in the range of 1.80 to 10.0, preferably in the range of 2.00 to 8.0, and more preferably in the range of 2.5 to 5.0.

[0093] Shear thinning index SHI 0 / 50 It is the ratio of the complex viscosity (η*0) at 190℃ and with a shear stress of 0 kPa to the complex viscosity (η*50) at 190℃ and with a shear stress of 50 kPa.

[0094] Alternatively or additionally, the metallocene-catalyzed multimodal copolymer (P) is further characterized by a shear thinning index SHI as described in the experimental section. 1 / 100 It is in the range of greater than 2.2 to 10.0, preferably in the range of 2.5 to 8.0, and more preferably in the range of 3.0 to 5.0.

[0095] Shear thinning index SHI 1 / 100 It is the ratio of the complex viscosity (η*1) at 190℃ and a shear stress of 1 kPa to the complex viscosity (η*100) at 190℃ and a shear stress of 100 kPa.

[0096] Metallocene-catalyzed multimodal copolymers (P) can be produced using a three-stage process, preferably comprising a first slurry reactor (loop reactor 1) connected in series with another slurry reactor (loop reactor 2), such that a first ethylene polymer fraction (A-1) produced in loop reactor 1 is fed into loop reactor 2, where a second ethylene polymer fraction (A-2) is produced in the presence of the first fraction (A-1). Loop reactor 2 is then connected in series with a gas-phase reactor (GPR), such that the first ethylene polymer component (A) exiting the second slurry reactor is fed into the GPR to produce a trimodal polyethylene copolymer. In this case, the reaction conditions in the two slurry reactors are selected such that products with different MFRs and / or densities are produced in the two slurry reactors.

[0097] This method is 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] The appropriate process is the Borstar PE process or the Borstar PE 3G process.

[0099] Therefore, the metallocene-catalyzed multimodal copolymer (P) according to the invention is preferably produced in a loop-gas phase cascade or a loop-loop-gas phase cascade. A prepolymerization step may precede such a polymerization step. The purpose of prepolymerization is to polymerize a small amount of polymer onto the catalyst at low temperature and / or low monomer concentration. Prepolymerization can improve the performance of the catalyst in the slurry and / or alter the properties of the final polymer. This prepolymerization step is preferably carried out in the slurry, and the amount of polymer produced in the optional prepolymerization step is taken as the amount (wt%) of the ethylene polymer component (A).

[0100] When a prepolymerization step is present, it is preferable that all of the catalyst components be introduced into the prepolymerization step. However, when the solid catalyst components and cocatalysts can be fed separately, it is possible that only a portion of the cocatalyst is introduced into the prepolymerization stage, while the remainder is introduced into the subsequent polymerization stage. Furthermore, in this case, it is necessary to introduce so much cocatalyst into the prepolymerization stage in order to achieve sufficient polymerization reaction therein.

[0101] It should be understood that, within the scope of this invention, the amount of polymer produced in the prepolymerization is between 1.0 and 5.0 wt% relative to the final metallocene-catalyzed multimodal copolymer (P). This can be considered as part of the first ethylene polymer component (A).

[0102] catalyst

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

[0104] Organometallic compounds (C) contain transition metals (M) of elements in groups 3 to 10 of the periodic table (IUPAC 2007), or of the actinides or lanthanides.

[0105] According to the present invention, the term "organometallic compound (C)" includes any metallocene or nonmetallocene compound of transition metals, which has at least one organic (coordinating) ligand and exhibits catalytic activity alone or in combination with a co-catalyst. Transition metal compounds are well known in the art, and the present invention covers compounds from Groups 3 to 10 of the periodic table (IUPAC 2007), such as Groups 3 to 7, or Groups 3 to 6, such as Groups 4 to 6, and compounds of lanthanides or actinides.

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

[0107]

[0108] 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;

[0110] L is -R'2Si-, where each R' is independently a C substituted with an alkoxy group having 1 to 10 carbon atoms. 1-20 - Hydrocarbon group or C 1-10 -alkyl;

[0111] M is Ti, Zr, or Hf;

[0112] Each R 1 Same or different, is C 1-6 -alkyl or C 1-6 -alkoxy group;

[0113] Each n is between 1 and 2;

[0114] Each R 2 Same or different, is C 1-6 -alkyl, C 1-6 -alkoxy or -Si(R)3 group;

[0115] Each R is arbitrarily selected by 1 to 3 Cs. 1-6 -alkyl-substituted C 1-10 -alkyl or phenyl; and

[0116] Each p is between 0 and 1.

[0117] Preferably, the compound of formula (I) has the following structure

[0118]

[0119] Each X is independently a halogen atom, C 1-6 -alkyl, C 1-6 -alkoxy, phenyl, or benzyl;

[0120] L is Me2Si-;

[0121] Each R 1 Same or different and is C 1-6 -alkyl, such as methyl or tert-butyl;

[0122] Each n is between 1 and 2;

[0123] R 2 It is a -Si(R)3 alkyl group; each p is 1;

[0124] Each R is C 1-6 -alkyl or phenyl.

[0125] The highly preferred formula (I) complex is

[0126]

[0127]

[0128] Most preferably, the complex dimethylsilanediylbis[2-(5-trimethylsilylfuran-2-yl)-4,5-dimethylcyclopentadien-1-yl]zirconium dichloride is used.

[0129] More preferably, the ethylene polymer components (A) and (B) of the multimodal copolymer (P) are prepared using the same metallocene catalyst, i.e., in the presence of the same metallocene catalyst.

[0130] To form the catalyst, a co-catalyst, also known as an activator, is used. Co-catalysts containing Al or B are well known and can be used here. Aluminoxanes (e.g., MAO) or boron-based co-catalysts (e.g., borates) are preferred.

[0131] In contrast to Ziegler-Natta catalysis, polyethylene copolymers prepared using site-specific catalysis exhibit characteristics that distinguish them from Ziegler-Natta materials. In particular, the comonomer distribution is more uniform. This can be visualized using TREF or Crystaf techniques. Catalyst residues can also indicate the catalyst used. Ziegler-Natta catalysts do not contain, for example, Zr or Group IV (Hf) metals.

[0132] Metallocene-catalyzed multimodal copolymers (P) may contain other polymer components and optional additives and / or fillers. When metallocene-catalyzed multimodal copolymers (P) contain other polymer components, the amount of the other polymer components typically varies between 3.0 and 20.0 wt%, depending on the total amount of the metallocene-catalyzed multimodal copolymer (P) and the other polymer components.

[0133] Optional additives and fillers, and their amounts, are common in membrane applications. Examples of such additives include antioxidants, processing stabilizers, UV stabilizers, pigments, fillers, antistatic additives, antiblocking agents, nucleating agents, acid scavengers, and polymer processing aids (PPAs).

[0134] It should be understood here that any additives and / or fillers may optionally be added to a so-called masterbatch containing the corresponding additives and carrier polymers. In this case, based on the total amount (100 wt%) of the polymer composition, the carrier polymer is not calculated in the polymer component of the metallocene-catalyzed multimodal copolymer (P), but rather in the amount of the corresponding additives.

[0135] The membrane of the present invention

[0136] Another embodiment of the invention further relates to the use of the metallocene-catalyzed multimodal polyethylene copolymer (P) as defined above in the production of blown films, and blown films made from such metallocene-catalyzed multimodal polyethylene copolymer (P).

[0137] The membrane of the present invention comprises at least one layer containing a metallocene-catalyzed multimodal copolymer (P). The membrane may be a monolayer membrane containing a metallocene-catalyzed multimodal copolymer (P) or a multilayer membrane wherein at least one layer contains a metallocene-catalyzed multimodal copolymer (P). The terms "monolayer membrane" and "multilayer membrane" have well-known meanings in the art.

[0138] The single-layer or multi-layer membranes of the present invention may consist of the metallocene-catalyzed multimodal copolymer (P) itself, or a blend of the metallocene-catalyzed multimodal copolymer (P) with other polymers. In the case of blends, any other polymer is different from the metallocene-catalyzed multimodal copolymer (P), and is preferably a polyolefin. A portion of the aforementioned additives, such as processing aids, may optionally be added to the metallocene-catalyzed multimodal copolymer (P) during the membrane preparation process.

[0139] 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%, and still more preferably at least 80 wt% of the metallocene-catalyzed multimodal copolymer (P) of the present invention. Most preferably, the at least one layer of the membrane of the present invention is composed of a metallocene-catalyzed multimodal copolymer (P).

[0140] Therefore, the membrane of the present invention may comprise a single layer (i.e., a monolayer) or may comprise multiple layers. Multilayer membranes typically and preferably comprise at least three layers.

[0141] The film is preferably produced by any conventional blown film extrusion process known in the art. More preferably, the blown film is produced by extrusion via an annular die and by blowing into a tubular film by forming bubbles, which rupture between rolls after solidification. The film can then be cut, diced, or transformed (e.g., folded) as needed. Conventional film production techniques can be used in this regard. If the blown film is a multilayer film, the layers are typically co-extruded. Those skilled in the art will know the appropriate extrusion conditions.

[0142] The membrane according to the invention can undergo post-processing, such as surface modification, lamination, or orientation processes. Such orientation processes can be uniaxial (MDO) or biaxial orientation, with uniaxial orientation being preferred.

[0143] In another preferred embodiment, the membrane is non-oriented.

[0144] The resulting membrane can have any thickness conventional in the art. The membrane thickness is not critical and depends on the end use. Therefore, the membrane can have a thickness of, 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 polymers of the present invention can achieve thicknesses of less than 100 μm, for example, less than 50 μm. Membranes of the present invention with thicknesses even less than 20 μm can also be produced while maintaining good mechanical properties.

[0145] Furthermore, the present invention relates to the use of the articles of the invention as packaging materials, particularly as packaging materials for food and / or medical products.

[0146] The present invention further relates to a membrane comprising at least one layer of a multimodal polyethylene copolymer (P) containing a metallocene catalyst.

[0147] The membrane is characterized by a sealing initiation temperature (SIT) of less than 97°C, preferably in the range of 60 to 96°C, more preferably in the range of 70 to 95°C, and even more preferably in the range of 80 to 94°C, as described in the experimental section on a 40 μm monolayer test blown film.

[0148] In the embodiments, the membrane comprising the metallocene-catalyzed multimodal copolymer (P) is further characterized by a dart impact strength (DDI) of at least 500g to greater than 1700g, preferably 600g to 1500g, and more preferably 700g to 1200g, as determined by ASTM D1709 Method A on a 40μm monolayer test blown film.

[0149] The upper limit of "greater than 1700g" is because the detection limit of the corresponding method is 1700g.

[0150] Therefore, in a preferred embodiment, the membrane comprising a metallocene-catalyzed multimodal polyethylene copolymer (P) is characterized by having at least […].

[0151] a) A sealing initiation temperature measured on a blown film with a thickness of 40 μm as described in the experimental section, below 97°C, preferably in the range of 60°C to 96°C, more preferably in the range of 70°C to 95°C, and even more preferably in the range of 80°C to 94°C.

[0152] as well as

[0153] b) A dart impact strength (DDI) of at least 500g to greater than 1700g, preferably 600g to 1500g, more preferably 700g to 1200g, determined on a 40μm monolayer test blown film according to ASTM D1709 Method A.

[0154] Furthermore, the membrane according to the invention has good stiffness (tensile modulus measured on a 40 μm monolayer blown film according to ISO 527-3), i.e., >150 MPa (in both directions).

[0155] Therefore, the film containing the metallocene-catalyzed multimodal copolymer (P) further or additionally has longitudinal (MD) and transverse (TD) tensile moduli in the range of >150 MPa to 400 MPa, preferably 200 MPa to 350 MPa (measured on a 40 μm monolayer test blown film according to ISO 527-3).

[0156] The specific design of the metallocene-catalyzed multimodal copolymer (P) of the present invention makes this polymer highly advantageous for membrane fabrication. Compared to corresponding membrane materials with the same density and MFR level, the use of the metallocene-catalyzed multimodal copolymer (P) of the present invention in a membrane fabrication machine yields superior compressibility, and in particular, a significantly higher yield. This higher potential yield is not achieved at the expense of good mechanical properties.

[0157] Membranes made from such metallocene-catalyzed multimodal polyethylene copolymers (P) also have an improved balance of performance, particularly considering the lower seal initiation temperature (SIT), higher stiffness (i.e., tensile modulus), and good impact strength (i.e., dart impact, DDI).

[0158] The present invention will be further described with reference to the following non-limiting embodiments. Detailed Implementation

[0159] Determination methods

[0160] Unless otherwise stated in the instructions or experimental section, the following methods are used to determine the performance of polymers (including their parts and components) and / or any sample formulations thereof as described in the text or experimental section.

[0161] melt flow rate

[0162] Melt flow rate (MFR) is determined according to ISO 1133 and expressed in g / 10 min. MFR is an indicator of polymer flowability and therefore also an indicator of polymer processing performance. A higher melt flow rate generally indicates a lower polymer viscosity. The MFR of polyethylene is measured at 190°C. MFR can be measured under different loads, such as 2.16 kg (MFR2), 5 kg (MFR5), or 21.6 kg (MFR6). 21 ).

[0163] Calculation of MFR2 for component B and part (A-2)

[0164] logA = x·logB + (1-x)·logC

[0165]

[0166] For component B:

[0167] B = MFR2 of component (A)

[0168] C = MFR2 of component (B)

[0169] A = Final MFR2 (mixture) of multimodal polyethylene copolymer (P)

[0170] X = weight fraction of component (A)

[0171] For part (A-2):

[0172] B = MFR2 of Part 1 (A-1)

[0173] C = MFR2 of Part 2 (A-2)

[0174] A = the final MFR2 (mixture) of the cyclic polymer (= component (A)).

[0175] X = weight fraction of part 1 (A-1)

[0176] density

[0177] The polymer density was measured according to ASTM D792, Method B (equilibrium density at 23°C) on compression-molded specimens prepared according to EN ISO 1872-2, in kg / m³. 3 .

[0178] Comonomer content:

[0179] Quantitative analysis of microstructure using NMR spectroscopy

[0180] Quantitative nuclear magnetic resonance (NMR) spectroscopy is used to quantify the comonomer content of polymers.

[0181] Using a Bruker Avance III 500 NMR spectrometer, the NMR spectrometer was used to measure the NMR spectrum at 500.13 MHz and 125.76 MHz. 1 H and 13 C performs the operation, recording a quantitative value in the molten state. 13 C{ 1 H NMR spectroscopy. All spectra were performed using H NMR spectroscopy. 13A C-optimized 7mm magic angle rotation (MAS) probe was used for recording at 150°C, with nitrogen used for all pneumatic devices. Approximately 200 mg of material was loaded into a 7mm outer diameter (d) zirconia MAS rotor and rotated at 4 kHz. This setup was chosen primarily for the high sensitivity required for rapid identification and accurate quantification. Standard single-pulse excitation was employed, utilizing a 3-second short-cycle delay NOE and an RS-HEPT decoupling scheme. A total of 1024 (1k) transients were obtained for each spectrum.

[0182] Quantitative 13 C{ 1 The ¹H NMR spectra were processed, integrated, and the relevant quantitative characteristics were determined by integration. All chemical shifts were internally referenced to the bulk methylene signal (δ+) at 30.00 ppm.

[0183] The amount of ethylene was quantified by integrating the number of methylene (δ+) sites per monomer reporter site at 30.00 ppm:

[0184] E=Iδ+ / 2

[0185] The presence of isolated comonomer units is corrected based on the number of existing isolated comonomer units: Etotal = E + (3*B + 2*H) / 2

[0186] B and H are defined for their respective comonomers. Corrections are made in a similar manner when continuous and discontinuous comonomers are incorporated.

[0187] Observing the characteristic signal corresponding to the incorporation of 1-butene, the comonomer fraction was calculated as the fraction of 1-butene in the polymer relative to all monomers in the polymer:

[0188] fB total = B total / (E total + B total + H total)

[0189] The amount of isolated 1-butene incorporated into the EEBEE sequence was quantified by integrating the B2 site at 39.8 ppm as a percentage of the number of reporter sites per comonomer:

[0190] B = I *B2

[0191] If present, the amount of sequentially incorporated 1-butene in the EEBBEE sequence is quantified by integrating the number of comonomer reporter sites at 39.4 ppm ααB2B2 sites as a percentage of the total number of comonomer reporter sites:

[0192] BB=2*IααB2B2

[0193] The amount of discontinuous 1-butene incorporated into the EEBBEE sequence was quantified by integrating the number of ββB2B2 sites per comonomer reporter site at 24.6 ppm:

[0194] BEB=2*IββB2B2

[0195] Since the *B2 and *βB2B2 sites of the isolated (EEBEE) and discontinuously incorporated (EEBEBEE)1-butene overlap, the total amount of isolated 1-butene incorporated is corrected based on the amount of discontinuous 1-butene present: B = I *B2 -2*I ββB2B2

[0196] No BBB sequence was observed. The total 1-butene content was calculated based on the sum of isolated, continuous, and discontinuously incorporated 1-butene:

[0197] Total B = B + BB + BEB

[0198] Then calculate the total mole fraction of 1-butene in the polymer:

[0199] fB = B total / (E total + B total + H total)

[0200] Characteristic signals corresponding to 1-hexene incorporation were observed, and the comonomer fraction was calculated as the fraction of 1-hexene in the polymer relative to all monomers in the polymer:

[0201] fH total = H total / (E total + B total + H total)

[0202] The amount of isolated 1-hexene incorporated into the EEHEE sequence was quantified by integrating the number of *B4 sites at 38.3 ppm relative to the number of reporter sites per comonomer:

[0203] H = I *B4

[0204] If present, the amount of sequentially incorporated 1-butene in the EEHHEE sequence is quantified by integrating the number of ααB4B4 sites at 40.5 ppm relative to the number of reporter sites per comonomer:

[0205] HH=2*IααB4B4

[0206] If present, the amount of discontinuously incorporated 1-hexene in the EEHEHEE sequence is quantified by integrating the number of ββB4B4 sites per comonomer reporter site at 24.7 ppm:

[0207] HEH=2*IββB4B4

[0208] No HHH sequence was observed. The total 1-hexene content was calculated based on the sum of isolated, continuous, and discontinuously incorporated 1-hexene:

[0209] H total = H + HH + HEH

[0210] Then calculate the total mole fraction of 1-hexene in the polymer:

[0211] fH = H total / (E total + B total + H total)

[0212] The molar percentage of comonomer incorporated is calculated from the mole fraction:

[0213] B[mol%]=100*fB

[0214] H[mol%]=100*fH

[0215] The weight percentage of comonomer incorporated is calculated as a mole fraction:

[0216] B[wt%]=100*(fB*56.11) / ((fB*56.11)+(fH*84.16)+((1-(fB+fH))*28.05)) H[wt%]=100*(fH*84.16) / ((fB*56.11)+(fH*84.16)+((1-(fB+fH))*28.05))

[0217] References:

[0218] Klimke, K., Parkinson, M., Piel, C., Kaminsky, W., Spiess, HW, Wilhelm, M., Macromol. Chem. Phys. 2006; 207:382.

[0219] Parkinson, M., Klimke, K., Spiess, HW, Wilhelm, M., Macromol. Chem. Phys. 2007; 208:2128.

[0220] Pollard,M.,Klimke,K.,Graf,R.,Spiess,HW,Wilhelm,M.,Sperber,O.,Piel,C.,Kaminsky,W.,Macromolecules 2004;37:813.

[0221] Filip,X.,Tripon,C.,Filip,C.,J.Mag.Resn.2005,176,239

[0222] Griffin,JM,Tripon,C.,Samoson,A.,Filip,C.,and Brown,SP,Mag.Res.inChem.2007 45,S1,S198

[0223] Castignolles,P.,Graf,R.,Parkinson,M.,Wilhelm,M.,Gaborieau,M.,Polymer50(2009)2373

[0224] Busico,V.,Cipullo,R.,Prog.Polym.Sci.26(2001)443

[0225] Busico,V.,Cipullo,R.,Monaco,G.,Vacatello,M.,Segre,AL,Macromoleucles30(1997)6251

[0226] Zhou,Z.,Kuemmerle,R.,Qiu,X.,Redwine,D.,Cong,R.,Taha,A.,Baugh,D.Winniford,B.,J.Mag.Reson.187(2007)225

[0227] Busico,V.,Carbonniere,P.,Cipullo,R.,Pellecchia,R.,Severn,J.,Talarico,G.,Macromol.Rapid Commun.2007,28,1128

[0228] Resconi,L.,Cavallo,L.,Fait,A.,Pimontesi,F.,Chem.Rev.2000,100,1253

[0229] Rheology:

[0230] Characterization of the polymer melt by dynamic shear measurements conformed to ISO standards 6721-1 and 6721-10. Measurements were performed on an Anton Paar MCR501 stress-controlled rotational rheometer equipped with a 25 mm parallel plate geometry. Strain was set in a nitrogen atmosphere within the linear viscoelastic range, and measurements were taken on a pressure plate. Oscillatory shear tests were performed at 190 °C with applied frequencies ranging from 0.01 to 600 rad / s and a set gap of 1.3 mm.

[0231] In dynamic shear experiments, the probe undergoes uniform deformation under sinusoidally varying shear strain or shear stress (strain and stress control modes, respectively). In controlled strain experiments, the probe is subjected to sinusoidal strain, which can be expressed by the following equation.

[0232] γ(t)=γ0 sin(ωt) (1)

[0233] If the applied strain is within the linear viscoelastic range, the resulting sinusoidal stress response can be given by the following equation.

[0234] σ(t)=σ0 sin(ωt+δ) (2)

[0235] Where σ0 and γ0 are the stress and strain amplitudes, respectively; ω is the angular frequency; δ is the phase shift (the loss angle between the applied strain and the stress response); and t is time.

[0236] Dynamic test results are typically represented by several different rheological functions, namely shear storage modulus G', shear loss modulus G”, complex shear modulus G*, complex shear viscosity η*, dynamic shear viscosity η', out-of-phase component of complex shear viscosity η”, and loss tangent tanη. They can be expressed as follows:

[0237]

[0238]

[0239] G*=G'+iG”[Pa] (5)

[0240] η*=η'-iη”[Pa·s] (6)

[0241]

[0242]

[0243] The so-called shear thinning index is related to MWD but not to molecular weight, and its determination is as described in Formula 9.

[0244]

[0245] For example, SHI (2.7 / 210) SHI is defined as the complex viscosity value (in Pa·s) measured at a G* value of 2.7 kPa divided by the complex viscosity value (in Pa·s) measured at a G* value of 210 kPa. (5 / 200) The complex viscosity value (in Pa·s) measured when the G* value is equal to 5 kPa is defined as the complex viscosity value (in Pa·s) measured when the G* value is equal to 200 kPa.

[0246] The values ​​of storage modulus (G'), loss modulus (G”), complex modulus (G*), and complex viscosity (η*) are obtained as a function of frequency (ω).

[0247] Therefore, for example, η* 300rad / s (eta* 300rad / s η* is used as an abbreviation for complex viscosity at a frequency of 300 rad / s. 0.05rad / s (eta* 0.05rad / s It is used as an abbreviation for complex viscosity with a frequency of 0.05 rad / s.

[0248] The loss tangent tan(δ) is defined as the ratio of the loss modulus (G”) to the storage modulus (G’) at a given frequency. Therefore, for example, tan… 0.05 Used as an abbreviation for the ratio of loss modulus (G”) to storage modulus (G’) at 0.05 rad / s, tan 300 Used as an abbreviation for the ratio of loss modulus (G”) to energy storage modulus (G’) at 300 rad / s.

[0249] Elastic balance tan 0.05 / tan 300 Defined as the loss tangent tan 0.05 tan and loss angle 300 The ratio.

[0250] In addition to the rheological functions mentioned above, other rheological parameters can be determined, such as the so-called elasticity index EI(x). The elasticity index EI(x) is the value of the storage modulus G' determined for a loss modulus G' of x kPa, and can be described by Equation 10.

[0251] For (G″=x kPa), EI(x)=G′[Pa] (10)

[0252] For example, EI(5kPa) is defined by the value of the energy storage modulus G' when the value of G” is equal to 5kPa.

[0253] The polydispersity index PI is defined by formula 11.

[0254]

[0255] Where ω COP The cross angular frequency is determined as the angular frequency when the energy storage modulus G' equals the loss modulus G”.

[0256] These values ​​are determined by a single-point interpolation procedure defined in the Rheoplus software. If the experiment fails to reach a given G* value, the value is determined by extrapolation using the same procedure as before. In both cases (interpolation or extrapolation), the Rheoplus options "Interpolate y-values ​​of parameters to x-values" and "Logarithmic interpolation" are applied.

[0257] References:

[0258] [1] "Rheological characterization of polyethylene fractions", Heino, EL, Lehtinen, A., Tanner J., J., Neste Oy, Porvoo, Finland, Theor.Appl.Rheol., Proc.Int.Congr.Rheol, Issue 11 (1992), 1, 360-362.

[0259] [2] "The influence of molecular structure on some rheological properties of polyethylene", Heino, EL, Borealis Polymers Oy, Porvoo, Finland, Annual Transactions of the Nordic Rheology Society, 1995.

[0260] [3]“Definition of terms relating to the non-ultimate mechanical properties of polymers”, Pure & Appl. Chem., Vol. 70, No. 3, pp. 701-754, 1998.

[0261] Sealing start temperature (SIT); Sealing end temperature (SET); Sealing range:

[0262] This method determines the sealing temperature range (sealing range) of polyethylene films, particularly blown or cast films. The sealing temperature range is the temperature range within which the film can be sealed according to the conditions given below.

[0263] The lower limit (heat seal initiation temperature (SIT)) is the sealing temperature at which a seal strength ≥ 5N is achieved. The upper limit (seal end temperature (SET)) is reached when the membrane adheres to the sealing device.

[0264] Measurements were performed according to a slightly modified version of ASTM F1921–12, with modifications made to the test parameters: sealing pressure, cooling time, and test speed. The force / temperature profile was continued until thermal failure of the membrane.

[0265] The sealing range was determined using a blown film with a thickness of 40 μm on a J&B General Seal Machine Model 4000.

[0266] And it has the following further parameters:

[0267] Adjustment time: >96h

[0268] Sample width: 25mm

[0269] Sealing pressure: 0.4 N / mm 2 (PE)

[0270] Sealing time: 1 second

[0271] Delay time: 30 seconds

[0272] Sealing clamp size: 50 x 5 mm

[0273] Sealing clamp shape: flat

[0274] Sealing clamp coating: Niptef

[0275] Sealing temperature: ambient temperature -240℃

[0276] Sealing temperature interval: 5℃

[0277] Starting temperature: 50℃

[0278] Clamping separation rate: 42mm / sec

[0279] Dart Drop Intensity (DDI)

[0280] Dart dropping measurements were performed on the membranes produced as shown below using ASTM D1709 Method A (Alternative Test Technique). Darts with hemispherical heads and a diameter of 38 mm were dropped from a height of 0.66 m onto the multilayer membrane clamped in a hole. Twenty sets of samples were tested consecutively. One weight was used for each set, and the weight increased (or decreased) in uniform increments between sets. The weight that caused 50% of the samples to break was calculated and reported.

[0281] tensile modulus

[0282] The longitudinal and / or transverse tensile modulus (E-Mod (MPa)) was measured according to ISO 527-3 on a membrane sample prepared as described in the membrane sample preparation, with a membrane thickness of 40 μm and a crosshead speed of 1 mm / min.

[0283] Experimental Section

[0284] Example: Preparation of the catalyst (CAT1) of this invention

[0285] SiO2 loading:

[0286] Add 10 kg of silica (PQ Corporation ES757, calcined at 600°C) from the feed hopper and inertize it in the reactor until the O2 level is below 2 ppm.

[0287] Preparation of MAO / tol / MC:

[0288] At 25°C (oil circulation temperature) and with stirring at 95 rpm, 30 wt% MAO in toluene (14.1 kg) was added from a balance to another reactor, followed by the addition of toluene (4.0 kg). After the addition of toluene, the stirring speed was increased from 95 rpm to 200 rpm, and the stirring time was 30 minutes. 477 g of metallocene racemic dimethylsilanediylbis{2-(5-(trimethylsilyl)furan-2-yl)-4,5-dimethylcyclopentadien-1-yl}zirconium dichloride was added from a metal cylinder, followed by rinsing with 4 kg of toluene (total toluene was 8.0 kg). The reactor stirring speed was changed to 95 rpm for MC feed, then returned to 200 rpm and maintained for 3 hours of reaction. After the reaction time, the MAO / tol / MC solution was transferred to a feed vessel.

[0289] Preparation of catalysts:

[0290] The reactor temperature was set to 10℃ (oil circulation temperature) and MAO / tol / MC was added with stirring at 40 rpm. The MAO / tol / MC solution (target 22.5 kg, actual 22.2 kg) was added over 205 min, followed by stirring for 60 min (oil circulation temperature set to 25℃). After stirring, the "dry mixture" was stabilized at 25℃ (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 5 rpm.

[0291] After stabilization, the catalyst was dried at 60°C (oil circulation temperature) for 2 hours under a nitrogen flow of 2 kg / h, followed by vacuum drying for 13 hours (with the same nitrogen flow and stirring at 5 rpm). Samples of the dried catalyst were taken, and the HC content was measured using thermogravimetric analysis with a Sartorius moisture analyzer (model MA45) in a glove box. The target HC level was <2% (actual 1.3%).

[0292] Comparative catalyst (CAT2)

[0293] As catalyst CAT2, a supported catalyst containing aluminoxane was used. This catalyst contains metallocene di(1-methyl-3-n-butylcyclopentadienyl)zirconium chloride (IV) and has enhancements from Grace. Activator technology.

[0294] Polymerization: Embodiment of the present invention: The multimodal polyethylene copolymer (P) of the present invention having 1-butene and 1-hexene comonomers

[0295] The Borstar pilot plant includes a three-reactor unit (loop 1 – loop 2 – GPR1) and a prepolymer loop reactor.

[0296] The multimodal copolymer (P) of the present invention in Example 1 (IE1) and the comparative example (CE1) were produced using the polymerization conditions given in Table 1.

[0297] Table 1: Aggregation Conditions

[0298]

[0299] The polymer was mixed with 2400 ppm of Irganox B561 and 270 ppm of Dynamar FX 5922, compounded and extruded into granules under a nitrogen atmosphere using a JSW extruder at a melt temperature of 200°C and a production rate of approximately 220 kg / h.

[0300] Table 2: Material properties of the multimodal copolymer (P) of the present invention and the comparative copolymer

[0301]

[0302] Surprisingly, the bimodal distribution of MFR2 in Example IE of the present invention (i.e., MFR2(A) / MFR2(final) in Example IE of the present invention) is lower than that in Comparative Example CE, however, the copolymer (P) of the present invention in IE has higher SHI and PI.

[0303] Membrane sample preparation

[0304] Test films with a thickness of 40 μm, consisting of the multimodal copolymer (P) of the present invention and their respective comparative polymers, were prepared using an Alpine 7-layer machine with 7 extruders.

[0305] As embodiments of the present invention (IE1 and IE2), the polymer IE of the present invention is processed at production rates of 190 kg / h and 240 kg / h, respectively. The comparative embodiment (CE) is processed only at a production rate of 190 kg / h. Further membrane processing parameters are shown in Table 3.

[0306] Table 3: Membrane processing parameters

[0307]

[0308]

[0309] As can be seen from the table above, the advantage of the polymer (P) of the present invention in IE is that the die pressure of each extruder A to G in IE-1 is lower than that in CE (both have a production capacity of 190 kg / h), and when the production capacity is 240 kg / h, it is increased to a level comparable to the comparative example (IE-2). Therefore, using the polymer (P) of the present invention, a higher level of production capacity can be achieved at a die pressure comparable to that of the comparative example (190 kg / h production capacity).

[0310] In addition, the traction speed increased from 30 m / min to 38 m / min, which means that the production rate increased by approximately +25%.

[0311] The properties of the membrane are shown in Table 4.

[0312] Table 4: Properties of a 40 μm thick film

[0313]

[0314]

[0315] nm not measured

[0316] As can be clearly seen from the table above, the improved processing performance of the multimodal copolymer (P) of the present invention has no negative impact on the film properties. That is, the film composed of the multimodal copolymer (P) of the present invention exhibits even lower seal initiation temperature (SIT), higher tensile modulus and comparable DDI, thus having improved overall performance.

Claims

1. A metallocene-catalyzed multimodal polyethylene copolymer (P) of ethylene and at least two different comonomers selected from α-olefins having 4 to 10 carbon atoms, comprising the following... (i) 30.0 to 70.0 wt% of ethylene polymer component (A), and (ii) 70.0 to 30.0 wt% of ethylene polymer component (B), The ethylene polymer component (A) has 920 to 950 kg / m 3 The density range and MFR2 (190℃, 2.16 kg, ISO 1133) range from 1.0 to 20.0 g / 10 min, and The ethylene polymer component (A) is composed of an ethylene polymer portion (A-1) and an ethylene polymer portion (A-2). The ethylene polymer portions (A-1) and (A-2) have a strength of 920 to 960 kg / m³. 3 The density within the range, and the MFR2 (190°C, 2.16 kg, ISO 1133) within the range of 0.5 to 100.0 g / 10 min, and The MFR2 of the ethylene polymer portions (A-1) and (A-2) are different from each other, and The density of polymer portion (A-2) is the same as or different from the density of polymer portion (A-1); and The ethylene polymer component (B) has 890 to 915 kg / m 3 Density within the range and MFR2 (190℃, 2.16 kg, ISO 1133) within the range of 0.01 to 1.5 g / 10 min; and The multimodal polyethylene copolymer (P) has a) Between 910 and 940 kg / m 3 Density within a certain range b) MFR2 in the range of 0.1 to 10.0 g / 10 min (190 °C, 2.16 kg, ISO 1133). c) MFR greater than 20 and less than or equal to 50 21 The ratio of MFR (190℃, 21.6 kg, ISO 1133) to MFR2 (190℃, 2.16 kg, ISO 1133) MFR 21 / MFR2, d) is defined as 10 5 / Gc is the rheological polydispersity index, where Gc is the cross modulus of dynamic rheology at 190 °C according to ISO 6271-10, which is greater than 0.57 and less than or equal to 2.0 Pa. -1 ,and e) Shear thinning index SHI greater than 1.80 and less than or equal to 10.0 0 / 50 .

2. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 1, wherein the ethylene polymer component (A) is composed of an ethylene polymer portion (A-1) and an ethylene polymer portion (A-2). The ethylene polymer portions (A-1) and (A-2) have a strength of 925 to 955 kg / m³. 3 The density within the range and the MFR2 (190℃, 2.16 kg, ISO 1133) within the range of 1.0 to 50.0 g / 10 min, and The MFR2 of the ethylene polymer portions (A-1) and (A-2) are the same or different from each other; and The density of polymer portion (A-2) is the same as or different from that of polymer portion (A-1).

3. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 2, wherein the ethylene polymer portions (A-1) and (A-2) have a content of 930 to 950 kg / m³. 3 Density within the range.

4. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 2, wherein the ethylene polymer portions (A-1) and (A-2) have a content of 935 to 945 kg / m³. 3 Density within the range.

5. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 2, wherein the ethylene polymer portions (A-1) and (A-2) have an MFR2 (190°C, 2.16 kg, ISO 1133) in the range of 1.5 to 30.0 g / 10 min.

6. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 2, wherein the ethylene polymer portions (A-1) and (A-2) have an MFR2 (190°C, 2.16 kg, ISO 1133) in the range of 2.0 to 15.0 g / 10 min.

7. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 2, wherein the ethylene polymer portions (A-1) and (A-2) have an MFR2 (190°C, 2.16 kg, ISO 1133) in the range of 2.5 to 10.0 g / 10 min.

8. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 2, wherein the MFR2 of the ethylene polymer portions (A-1) and (A-2) are different from each other.

9. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 2, wherein the MFR2 of the ethylene polymer portion (A-2) is higher than the MFR2 of the ethylene polymer portion (A-1).

10. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 1 or 2, wherein... - The MFR2 of the ethylene polymer component (A) is 2.0 to 15 g / 10 min, and - The MFR2 of the ethylene polymer component (B) is 0.1 to 1.2 g / 10 min, and / or The MFR2 of the multimodal polyethylene copolymer (P) is in the range of 0.8 to 8.0 g / 10 min.

11. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 10, wherein the MFR2 of the ethylene polymer component (A) is 3.0 to 10 g / 10 min.

12. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 10, wherein the MFR2 of the ethylene polymer component (A) is 4.0 to 8.0 g / 10 min.

13. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 10, wherein the MFR2 of the ethylene polymer component (B) is 0.2 to 1.0 g / 10 min.

14. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 10, wherein the MFR2 of the ethylene polymer component (B) is 0.3 to 1.0 g / 10 min.

15. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 10, wherein the MFR2 of the multimodal polyethylene copolymer (P) is in the range of 1.0 to 5.0 g / 10 min.

16. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 10, wherein the MFR2 of the multimodal polyethylene copolymer (P) is in the range of 1.2 to 3.0 g / 10 min.

17. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 1 or 2, wherein the MFR 21 The ratio of MFR2 (190℃, 21.6kg, ISO 1133) to MFR3 (190℃, 2.16kg, ISO 1133) 21 / MFR2 is 21 to 40.

18. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 17, wherein the MFR 21 The ratio of MFR2 (190℃, 21.6kg, ISO 1133) to MFR3 (190℃, 2.16kg, ISO 1133) 21 / MFR2 is 25 to 35.

19. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 1 or 2, wherein the total amount of 1-butene, based on the multimodal polyethylene copolymer (P), ranges from 0.1 to 1.5 wt%, and Based on the multimodal polyethylene copolymer (P), the total amount of 1-hexene ranges from 2.0 to 20.0 wt%.

20. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 19, wherein the total amount of 1-butene is in the range of 0.2 to 1.2 wt% based on the multimodal polyethylene copolymer (P).

21. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 19, wherein the total amount of 1-butene based on the multimodal polyethylene copolymer (P) ranges from 0.3 to 1.0 wt%.

22. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 19, wherein the total amount of 1-hexene based on the multimodal polyethylene copolymer (P) ranges from 4.0 to 15.0 wt%.

23. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 19, wherein the total amount of 1-hexene based on the multimodal polyethylene copolymer (P) ranges from 5.0 to 12.0 wt%.

24. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 1 or 2, wherein, based on the ethylene-1-butene polymer component, the total amount (wt%) of 1-butene present in the ethylene polymer component (A) ranges from 0.5 to 5.0 wt%, and Based on the ethylene-1-hexene polymer component, the total amount (wt%) of 1-hexene present in the ethylene polymer component (B) ranges from 8.0 to 25.0 wt%.

25. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 24, wherein the total amount (wt%) of 1-butene present in the ethylene polymer component (A) ranges from 0.8 to 4.0 wt%, based on the ethylene-1-butene polymer component.

26. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 24, wherein the total amount (wt%) of 1-butene present in the ethylene polymer component (A) ranges from 1.0 to 3.0 wt%, based on the ethylene-1-butene polymer component.

27. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 24, wherein the total amount (wt%) of 1-butene present in the ethylene polymer component (A) ranges from 1.0 to 2.5 wt%, based on the ethylene-1-butene polymer component.

28. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 24, wherein the total amount (wt%) of 1-hexene present in the ethylene polymer component (B) ranges from 10.0 to 22.0 wt%, based on the ethylene-1-hexene polymer component.

29. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 24, wherein the total amount (wt%) of 1-hexene present in the ethylene polymer component (B) ranges from 12.0 to 20.0 wt%, based on the ethylene-1-hexene polymer component.

30. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 1 or 2, wherein the definition is 10 5 The rheological polydispersity index of / Gc ranges from 0.60 to 1.5 Pa. -1 Within the range, Gc is the cross modulus of dynamic rheology at 190°C according to ISO 6271-10 standard, and / or Shear thinning index SHI 0 / 50 The range is from 2.00 to 8.

0.

31. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 30, wherein the definition is 10 5 The rheological polydispersity index of / Gc ranges from 0.62 to 1.2 Pa. -1 Within the range.

32. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 30, wherein the shear thinning index SHI 0 / 50 It is in the range of 2.5 to 5.

0.

33. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 1 or 2, wherein the metallocene-catalyzed multimodal polyethylene copolymer (P) is further characterized by a shear thinning index SHI. 1 / 100 It is greater than 2.2 and less than or equal to 10.

0.

34. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 33, wherein the shear thinning index SHI of the metallocene-catalyzed multimodal polyethylene copolymer (P) is... 1 / 100 It is in the range of 2.5 to 8.

0.

35. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 33, wherein the shear thinning index SHI of the metallocene-catalyzed multimodal polyethylene copolymer (P) is... 1 / 100 Within the range of 3.0 to 5.

0.

36. The metallocene-catalyzed multimodal polyethylene copolymer (P) according to claim 1 or 2, wherein the multimodal polyethylene copolymer (P) is produced in the presence of a metallocene complex of formula (II): (II) 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-, where each R' is independently a C substituted with an alkoxy group having 1 to 10 carbon atoms. 1-20 - Hydrocarbon group or C 1-10 -alkyl; M is Ti, Zr, or Hf; Each R 1 Same or different, is C 1-6 -alkyl or C 1-6 -alkoxy group; Each n is between 1 and 2; Each R 2 Same or different, is C 1-6 -alkyl, C 1-6 -alkoxy or -Si(R)3 group; Each R is arbitrarily selected by 1 to 3 Cs. 1-6 -alkyl-substituted C 1-10 -alkyl or phenyl; and Each p is between 0 and 1.

37. A blown film comprising a metallocene-catalyzed multimodal polyethylene copolymer (P) according to any one of claims 1 to 36.

38. The membrane according to claim 37, wherein the membrane is characterized in that the sealing initiation temperature measured on a blown film with a thickness of 40 μm is in the range of less than 97°C.

39. The membrane according to claim 37, wherein the membrane is characterized in that the sealing initiation temperature measured on a blown film with a thickness of 40 μm is in the range of 60°C to 96°C.

40. The membrane according to claim 37, wherein the membrane is characterized in that the sealing initiation temperature measured on a blown film with a thickness of 40 μm is in the range of 70°C to 95°C.

41. The membrane according to claim 37, wherein the membrane is characterized in that the sealing initiation temperature measured on a blown film with a thickness of 40 μm is in the range of 80 to 94°C.

42. The membrane of claim 37, wherein the membrane is characterized in that the dart impact strength (DDI) measured on a 40 μm monolayer test blown film according to ASTM D1709, Method A, is 500 g to 1200 g.

43. The membrane of claim 37, wherein the membrane is characterized in that the dart impact strength (DDI) measured on a 40 μm monolayer test blown film according to ASTM D1709, Method A, is 600 g to 1000 g.

44. The membrane of claim 37, wherein the membrane is characterized in that the dart impact strength (DDI) measured on a 40 μm monolayer test blown film according to ASTM D1709, Method A, is 700 g to 900 g.

45. The membrane according to claim 37, wherein the membrane is characterized by having at least […]. a) Sealing initiation temperature measured on a blown film with a thickness of 40 μm, in the range below 97°C. as well as b) Dart impact strength (DDI) of 500 g to 1200 g, determined on a 40 μm monolayer test blown film according to ASTM D1709 Method A.

46. ​​The membrane of claim 45, wherein the membrane has a sealing initiation temperature in the range of 60°C to 96°C, measured on a blown film with a thickness of 40 μm.

47. The membrane of claim 45, wherein the membrane has a sealing initiation temperature in the range of 70°C to 95°C, measured on a blown film with a thickness of 40 μm.

48. The membrane of claim 45, wherein the membrane has a sealing initiation temperature in the range of 80 to 94°C, measured on a blown film with a thickness of 40 μm.

49. The membrane of claim 45, wherein the membrane has a dart impact strength (DDI) of 600 g to 1000 g as determined by ASTM D1709 method A on a 40 μm monolayer test blown film.

50. The membrane of claim 45, wherein the membrane has a dart impact strength (DDI) of 700 g to 900 g as determined by ASTM D1709 Method A on a 40 μm monolayer test blown film.

51. The membrane according to claim 37, wherein the longitudinal (MD) and transverse (TD) tensile moduli of the membrane (measured according to ISO 527-3 on a 40 μm monolayer test blown film) are greater than 150 MPa and less than or equal to 400 MPa.

52. The membrane according to claim 51, wherein the longitudinal (MD) and transverse (TD) tensile moduli of the membrane (measured according to ISO 527-3 on a 40 μm monolayer test blown film) range from 200 MPa to 350 MPa.

53. Use of the film according to any one of claims 37 to 52 as a packaging material.

54. The use according to claim 53, wherein the packaging material is a packaging material for food and / or medical products.

Images