Ethylene-alpha-olefin copolymers and methods for making the same

Abstract

This invention provides an ethylene-α-olefin copolymer comprising a structural portion derived from ethylene and a structural portion derived from an α-olefin comprising 3 to 10 carbon atoms, wherein the copolymer has a short-chain branching ratio (SCBR) of >1.40, preferably >1.40 and <5.00, more preferably >1.60 and <5.00, even more preferably >1.80 and <4.00, even more preferably >2.00 and <3.00, wherein the SCBR is defined as (I), wherein the SCB 500 It is in M w = 500,000 g / mol, the amount of short-chain branches (SCB) in the copolymer and SCB 10 It is in M w = 10,000 g / mol, the amount of short-chain branching in the copolymer, wherein the SCB amount is determined by GPC-IR and expressed as the number of branches per 1000 carbon atoms ( / 1000C); · Short-chain branching content ≥15.0 / 1000C, preferably ≥15.0 and ≤35.0; · Molecular weight distribution M ≥10.0, preferably ≥10.0 and ≤20.0, more preferably ≥11.0 and ≤20.0, even more preferably ≥12.0 and ≤20.0, even more preferably ≥13.0 and ≤20.0. w / M n M w It is the weight-average molecular weight, and M n It is the number average molecular weight, M w and M n It is determined according to ASTM D6474 (2012); and the amount of polymeric structural portions derived from α-olefins containing 3 to 10 carbon atoms relative to the total weight of the copolymer. This copolymer exhibits improved melt processability and allows for the manufacture of films with desired mechanical properties, particularly in the production of films such as those produced by blown film or cast film.

Description

[0001] This invention relates to ethylene-α-olefin copolymers and methods for their preparation. Specifically, this invention relates to ethylene-α-olefin copolymers that achieve a desired balance between thermal processability in membrane preparation and the mechanical properties of the membranes obtained by this method.

[0002] As is well known, polymers produced from ethylene are the most widely available polymer materials. They can be produced economically with high and consistent product quality, and by changing, in particular, the polymerization conditions and feedstock formulations, multiple grades can be produced, each meeting certain application requirements and suitable for the production of a variety of products.

[0003] Polymers produced from ethylene are also known as polyethylene, and in some cases, monomers other than ethylene can be used as part of the feedstock formulation in the polymerization reaction. Typical additional monomers, called comonomers, can include α-olefins, particularly α-olefins having 3 to 10 carbon atoms. Such α-olefins containing 3 to 10 carbon atoms can be, for example, selected from propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, and 4-methyl-1-pentene. Particularly suitable compounds for use as comonomers are 1-butene, 1-hexene, and 1-octene.

[0004] In the ethylene-α-olefin copolymer according to the invention, a single comonomer may be used, or a combination of multiple comonomers may be used. Preferably, a single comonomer is used. Therefore, the ethylene-α-olefin copolymer according to the invention preferably comprises a structural portion derived from ethylene and a structural portion derived from the single comonomer.

[0005] One specific type of application that fully utilizes polyethylene is in films and film laminates. Various technologies exist for manufacturing films from polyethylene, including cast film production, blown film production, and oriented strand board (OSB) production. In each of these technologies, the polyethylene material is first brought to a molten state, and then the molten material is transformed into a film shape and solidified, typically by driving the molten material through a die of such size to allow the desired film to be obtained by the process, and then cooled below the melting point to allow the film to solidify.

[0006] To properly manufacture such membranes and ensure they meet desired properties, stringent conditions are set for the properties of polyethylene materials. Current trends in polyethylene membrane applications (such as combinations of increasing production speed, reducing membrane volume to decrease the amount of material used, and improving mechanical property requirements) are driving the polymer industry to continue developing polyethylene materials that meet these conditions. Further improvements can be achieved by developing materials with precisely designed molecular structures, which significantly impact the final properties of the materials.

[0007] In this respect, the present invention provides an ethylene-α-olefin copolymer comprising a structural portion derived from ethylene and a structural portion derived from an α-olefin comprising 3 to 10 carbon atoms, wherein the copolymer has:

[0008] • A short chain branching ratio (SCBR) >1.40, preferably >1.40 and <5.00.

[0009] Wherein, SCBR is defined as:

[0010]

[0011] SCB 500 It is in M w The amount of short-chain branches (SCB) in the copolymer at 500,000 g / mol and the SCB 10 It is in M w =10,000 g / mol, the amount of short chain branching of the copolymer, where the SCB amount is determined by GPC-IR and expressed as the number of branches per 1000 carbon atoms ( / 1000C);

[0012] • Short chain branch content ≥15.0 / 1000C, preferably ≥15.0 / 1000C and ≤35.0 / 1000C;

[0013] • Molecular weight distribution M ≥10.0, preferably ≥10.0 and ≤20.0 w / M n M w It is the weight-average molecular weight and M n It is the number average molecular weight, M w and M n It was determined according to ASTM D6474 (2012); and

[0014] • The amount of polymeric structural moieties derived from α-olefins containing 3 to 10 carbon atoms, relative to the total weight of the copolymer, is ≥1.0 and ≤20.0% by weight.

[0015] This copolymer exhibits improved melt processability and allows for the manufacture of films with desired mechanical properties, particularly in film production such as by blown film production or by cast film production.

[0016] M of ethylene-α-olefin copolymer w / M n For example, it can be ≥11.0 and ≤20.0, preferably ≥12.0 and ≤20.0, and more preferably ≥13.0 and ≤20.0.

[0017] The SCBR of the ethylene-α-olefin copolymer may be, for example, >1.60, preferably >1.80, more preferably >2.00. The SCBR of the ethylene-α-olefin copolymer may be, for example, >1.60 and <5.00, preferably >1.80 and <4.00, more preferably >2.00 and <3.00.

[0018] Ethylene-α-olefin copolymers may, for example, have a molecular weight ratio M of ≥3.0, preferably ≥3.0 and ≤10.0. z / M w M z The z-average molecular weight was determined according to ASTM D6474 (2012).

[0019] In the ethylene-α-olefin copolymer according to the invention, the α-olefin may be selected, for example, from 1-butene, 1-hexene, and 1-octene. Preferably, the α-olefin is 1-butene or 1-hexene. The ethylene-α-olefin copolymer comprises, relative to the total weight of the copolymer, ≥1.0 and ≤20.0 wt%, preferably ≥1.0 and ≤15.0 wt%, more preferably ≥1.0 and ≤10.0 wt%, even more preferably ≥2.0 and ≤10.0 wt%, and even more preferably ≥2.0 and ≤5.0 wt% of a polymeric structural portion derived from an α-olefin comprising 3 to 10 carbon atoms. Preferably, the ethylene-α-olefin copolymer comprises, relative to the total weight of the copolymer, ≥1.0 and ≤20.0 wt%, preferably ≥1.0 and ≤15.0 wt%, more preferably ≥1.0 and ≤10.0 wt%, even more preferably ≥2.0 and ≤10.0 wt%, and even more preferably ≥2.0 and ≤5.0 wt% of a polymeric structural portion derived from α-olefins selected from 1-butene, 1-hexene, and 1-octene. More preferably, the ethylene-α-olefin copolymer comprises, relative to the total weight of the copolymer, ≥1.0 and ≤20.0 wt%, preferably ≥1.0 and ≤15.0 wt%, more preferably ≥1.0 and ≤10.0 wt%, even more preferably ≥2.0 and ≤10.0 wt%, and even more preferably ≥2.0 and ≤5.0 wt% of a polymeric structural portion derived from α-olefins selected from 1-butene and 1-hexene. Even more preferably, the ethylene-α-olefin copolymer comprises ≥1.0 and ≤20.0% by weight, preferably ≥1.0 and ≤15.0% by weight, more preferably ≥1.0 and ≤10.0% by weight, even more preferably ≥2.0 and ≤10.0% by weight, and even more preferably ≥2.0 and ≤5.0% by weight, relative to the total weight of the copolymer, of a polymeric structural portion derived from 1-hexene.

[0020] In the context of this invention, the amount of polymeric structural moiety derived from α-olefins can be used. 13C10 NMR was measured on a Bruker Avance 500 spectrometer equipped with a cryogenically cooled probe operating at 125 °C, with the sample dissolved at 130 °C in C2D2Cl4 containing DBPC as a stabilizer.

[0021] The ethylene-α-olefin copolymer according to the present invention may, for example, have a concentration of ≥900 and ≤940 kg / m³. 3 Preferred weight is ≥910 and ≤925 kg / m³. 3 The density, which is determined according to ASTM D1505-18.

[0022] The ethylene-α-olefin copolymer according to the invention may, for example, have a melt mass flow rate of ≥0.1 and ≤25.0 g / 10 min at 2.16 kg and 190 °C, preferably ≥0.1 and ≤15.0 g / 10 min, more preferably ≥0.1 and ≤10.0 g / 10 min, even more preferably ≥0.1 and ≤5.0 g / 10 min, even more preferably ≥0.3 and ≤2.0 g / 10 min, and most preferably ≥0.5 and ≤1.5 g / 10 min.

[0023] The ethylene-α-olefin copolymer according to the invention may, for example, have a melt mass flow rate of ≥25.0 g / 10 min at 21.6 kg and 190 °C, preferably ≥30.0 ​​g / 10 min, preferably ≥30.0 ​​and ≤100.0 g / 10 min, more preferably ≥30.0 ​​and ≤75.0 g / 10 min, and even more preferably ≥30.0 ​​and ≤50.0 g / 10 min.

[0024] The ethylene-α-olefin copolymer according to the invention may, for example, have a melt index ratio of ≥25.0, preferably ≥25.0 and ≤100.0, more preferably ≥30.0 ​​and ≤75.0, and even more preferably ≥30.0 ​​and ≤50.0, calculated by dividing the melt mass flow rate at 2.16 kg and 190 °C by the melt mass flow rate at 21.6 kg and 190 °C.

[0025] In the context of this invention, the melt mass flow rate is determined according to ASTM D1238-20.

[0026] The ethylene-α-olefin copolymer according to the invention may, for example, exhibit two distinct peaks in crystallization elution fractionation (CEF), wherein the first peak is present in an elution temperature range of ≥65°C and ≤80°C, and the second peak is present in an elution temperature range of ≥85°C and ≤100°C.

[0027] The ethylene-α-olefin copolymer according to the invention may, for example, have an analytical temperature rise elution fractionation (a-TREF) distribution such that, within an elution temperature range of ≥30°C and ≤94°C, ≥80.0% by weight, preferably ≥80.0% and ≤95.0% by weight, is eluted relative to the total weight of the eluent material.

[0028] The ethylene-α-olefin copolymer according to the invention may, for example, have an analytical temperature rise elution fractionation (a-TREF) distribution such that, within an elution temperature range of ≤30°C, ≤5.0% by weight relative to the total weight of the eluent material is eluted.

[0029] The ethylene-α-olefin copolymer according to the invention may, for example, have an analytical temperature rise elution fractionation (a-TREF) distribution such that, in an elution temperature range of ≥94°C, ≤15.0% by weight, preferably ≤10.0% by weight, and more preferably ≤5.0% by weight, are eluted relative to the total weight of the eluent material.

[0030] The ethylene-α-olefin copolymer according to the invention may, for example, display two or more, preferably two, peaks in a graph presenting elution weight as a function of elution temperature determined by crystallization elution fractionation (CEF). A particularly preferred embodiment of the invention is in which the ethylene-α-olefin copolymer has a CEF dW / dt ratio at peak 2 of ≤5.0, preferably ≤3.0, more preferably ≤2.0, relative to the CEF dW / dt at peak 1, wherein peak 1 is the peak occurring at the lowest temperature in the CEF graph presenting elution weight as a function of elution temperature, and peak 2 is the peak following peak 1 in the direction of increasing temperature, and wherein the dW / dt of peak 1 is the elution weight at the temperature of peak 1 in weight percent, and the dW / dt of peak 2 is the elution weight at the temperature of peak 2 in weight percent, both relative to the total elution weight. In the context of the invention, CEF can be determined according to the methods described in the experimental section below.

[0031] In the context of this invention, the SCB amount is determined by infrared detection gel permeation chromatography (GPC-IR). GPC-IR analysis can be performed, for example, using a chromatograph such as the Polymer Char GPC-IR system equipped with three columns of 7.5 mm inner diameter and 300 mm length, packed with particles of average size 13 μm; or, for example, the Polymer Laboratories 13 μm PLgel Olexis, operating at 160 °C, equipped with an MCT IR detector, wherein 1,2,4-trichlorobenzene stabilized with 1 g / L butylhydroxytoluene can be used as the eluent, the flow rate is 1 ml / min, using a sample concentration of 0.7 mg / ml and an injection volume of 200 μl, wherein the molar mass is based on general GPC principles, using narrow and wide standards (0.5-2800 kg / mol, M... w / M n The calibration (for 4 to 15) was performed using the known Mark Houwink constants (α = 0.725 and logK = -3.721) of the PE calibrator. The short-chain branching content was determined by IR determination of CH3(I) CH3 ) and CH2(I CH2 The intensity ratio of I was determined by combining it with the calibration curve. The calibration curve is based on the strength ratio of I. CH3 / I CH2 SCB content (X) with varying intensity ratio SCB The graph of the SCBD curve was obtained. To obtain the calibration curve, a set of polyethylene resins (no fewer than five) (SCB standards) were used. All these SCB standards had known SCB levels and flat SCBD curves. Using the SCB calibration curve thus established, the short-chain branching distribution curves of the resins fractionated using the IR5-GPC system under the exact same chromatographic conditions as these SCB standards were obtained. Using predetermined methods, the I... CH3 / I CH2 The intensity ratio and elution time are converted into SCB content and molecular weight SCB calibration curves (i.e., I... CH3 / I CH2 The relationship between intensity ratio and elution volume is transformed into SCB distribution as a function of MWD by using the intensity ratio (comparing SCB content to intensity ratio) and the MW calibration curve (i.e., molecular weight versus elution time).

[0032] Furthermore, the present invention also relates to a method for producing ethylene-α-olefin copolymers.

[0033] In an embodiment, the present invention relates to a method for producing an ethylene-α-olefin copolymer according to the present invention, wherein the method comprises polymerizing ethylene and a certain amount of α-olefin having 3 to 10 carbon atoms in the presence of a catalyst system comprising a compound according to Formula I:

[0034]

[0035] R1 is selected from C2-C10 alkyl, preferably C3-C10 alkyl, C6-C20 aryl, or C7-C20 aralkyl; R2 is selected from H or C1-C10 alkyl; and R3, R4, R5, and R6 are independently selected from H, C1-C10 alkyl, C6-C20 aryl, or C7-C20 aralkyl; and R3 and R4, R4 and R5, or R5 and R6 can be linked to form a ring structure; each R10 is a hydrocarbon group, preferably C1-C4 alkyl; M is selected from Ti, Zr, and Hf, preferably zirconium or... Hafnium, most preferably M is zirconium; wherein X is an anionic ligand of M, preferably methyl, Cl, Br or I, most preferably methyl or Cl; wherein R10 is preferably C1-C4 alkyl, most preferably methyl; wherein R1 is preferably selected from isopropyl, phenyl and 3,5-dialkyl-1-phenyl, preferably 3,5-dimethyl-1-phenyl, 3,5-diethyl-1-phenyl, 3,5-diisopropyl-1-phenyl or 3,5-di(tert-butyl)-1-phenyl, most preferably R1 is isopropyl; and wherein each of R2-R6 is preferably H.

[0036] In the method according to the invention, the catalyst system may, for example, comprise a compound of formula I immobilized on a support, wherein the support is selected from talc, clay, or inorganic oxides, preferably silica, alumina, magnesium oxide, titanium oxide, or zirconium oxide. Silica is particularly preferred as the support. For example, the support may have a diameter of 200 to 900 μm. 2 / g surface area and / or >0.5 and <4.0 ml / g pore volume of silica.

[0037] The catalyst system may, for example, also include a cocatalyst compound. The function of this cocatalyst is to generate cations from the compound and form so-called non-coordinated or weakly coordinated anions. Such cocatalysts may, for example, be selected from cocatalysts containing aluminum or boron. Such aluminum-containing cocatalysts may, for example, be selected from aluminum oxanes, alkylaluminum compounds, and alkylaluminum chlorides. Usable aluminum oxanes include, for example, oligomeric linear, cyclic, and / or cage-like alkylaluminum oxanes. Suitable aluminum-containing cocatalysts may, for example, be selected from: methylaluminoxane, trimethylaluminum, triethylaluminum, triisopropylaluminum, tri-n-propylaluminum, triisobutylaluminum, tri-n-butylaluminum, tritert-butylaluminum, tripentylaluminum, dimethylethoxyaluminum, diethylethoxyaluminum, diisopropylethoxyaluminum, di-n-propylethoxyaluminum, diisobutylethoxyaluminum, di-n-butylethoxyaluminum, dimethylaluminum hydride, diethylaluminum hydride, diisopropylaluminum hydride, di-n-propylaluminum hydride, diisobutylaluminum hydride, and di-n-butylaluminum hydride. Suitable boron-containing cocatalysts include, for example, trialkylboranes, such as trimethylborane, triethylborane, and perfluoroarylborane compounds. For instance, a cocatalyst could be methylaluminoxane.

[0038] For example, the cocatalyst can be selected from cocatalysts containing aluminum or boron, preferably selected from aluminum oxanes, alkyl aluminum compounds and alkyl aluminum chlorides.

[0039] The method according to the invention can be, for example, gas-phase polymerization, slurry polymerization, or solution polymerization. In a particularly preferred embodiment, the method is a gas-phase polymerization operated in a polymerization apparatus comprising at least one fluidized bed reactor.

[0040] In some embodiments, the invention also relates to articles comprising the ethylene-α-olefin copolymer according to the invention, preferably wherein the article is a film or laminate. In one embodiment, the invention further relates to the use of the ethylene-α-olefin copolymer according to the invention for improving melt processability in the production of films by blown film production or by cast film production.

[0041] The present invention will now be illustrated by the following non-limiting embodiments.

[0042] Preparation of supported catalysts

[0043] Supported catalyst A

[0044] A 3L autoclave reactor equipped with a heating / cooling control unit and a mechanical stirring system was baked at 150°C for 2 hours under a nitrogen stream and then cooled to 30°C. 200g of Grace Sylopol 955W silica was pre-dehydrated at 600°C for 3 hours and loaded into the reactor, followed by the addition of 480ml of toluene. The metallocene compound was activated by mixing 2.44g of the metallocene compound Me2Si(Me4Cp)(1-(2-iPr-Ind))ZrCl2 (CAS registration number 2247072-26-8) with 514ml of a 10% by weight methylaluminoxane (MAO) solution for 30 minutes at 50°C. The activated metallocene was transferred to the autoclave reactor under stirring. An antistatic reagent modifier prepared by reacting 0.25g of cyclohexylamine and 0.50g of triisobutylaluminum in 200ml of toluene was added, and the reaction mixture was stirred at 50°C for 2 hours. After drying under a vacuum of 135 mbar at 75 °C, the finished catalyst was separated into a light yellow, free-flowing powder. This catalyst contained 0.18 wt% Zr and 8.5 wt% Al, corresponding to an Al / Zr molar ratio of 160.

[0045] Supported catalyst B

[0046] A 3L autoclave reactor equipped with a heating / cooling control unit and a mechanical stirring system was baked at 150°C for 2 hours under a nitrogen stream and then cooled to 30°C. 200g of Grace Sylopol 955W silica was pre-dehydrated at 600°C for 3 hours and loaded into the reactor, followed by the addition of 480ml of toluene. The metallocene compound was activated by mixing 2.03g of the metallocene compound Me2Si(Me4Cp)(1-(2-iPr-Ind))ZrCl2 (CAS registration number 2247072-26-8) with 513ml of a 10% by weight methylaluminoxane (MAO) solution for 30 minutes at 50°C. The activated metallocene was transferred to the autoclave reactor under stirring. An antistatic reagent modifier prepared by reacting 0.25g of cyclohexylamine and 0.50g of triisobutylaluminum in 200ml of toluene was added, and the reaction mixture was stirred at 50°C for 2 hours. After drying under a vacuum of 135 mbar at 75 °C, the finished catalyst was separated into a light yellow, free-flowing powder. The catalyst contained 0.15 wt% Zr and 8.5 wt% Al, corresponding to an Al / Zr molar ratio of 191.

[0047] Comparison of catalyst C

[0048] At room temperature, 0.595 kg of 2,2'-bis(2-indenyl)biphenylzirconium dichloride (CAS registration number 312968-31-3) was added to 36.968 kg of a 30% methylaluminoxane solution (Al content 13.58 wt%) in a first container, and stirred for 30 minutes to form an activated unit site catalyst component. 172 kg of dry toluene was added to 43 kg of a 300m... 2 Average surface area per g, 1.65 g / cm³ 3 average pore volume and Grace Sylopol 955W silica with an average pore size. The activated single-site catalyst component was added at 30°C. The temperature was raised to 50°C with stirring. The modifier was prepared by adding 0.114 kg of triisobutylaluminum to a solution of 0.057 kg of cyclohexylamine in 9.7 kg of dry toluene in a second container at room temperature. After maintaining the contents of the first container at 50°C for 2 hours, the modifier was added to the first container. The temperature was lowered to 30°C, toluene was removed by filtration, and the obtained single-site catalyst system was dried by raising the temperature to 55°C using a nitrogen stream. A solid single-site catalyst system was obtained.

[0049] polymerization

[0050] The polymerization experiments were conducted in a continuous gas-phase fluidized bed reactor with an inner diameter of 45 cm and a reaction zone height of 140 cm. The fluidized bed consisted of polymer particles. The reactor was filled with a bed of 40 kg of dry polymer particles, which were vigorously stirred by a high-speed gas flow. The polymer particle bed in the reaction zone was kept in a fluidized state by a circulating flow, which served as both a fluidizing medium and a heat dissipator to absorb the exothermic reaction generated in the reaction zone.

[0051] The flow rates of ethylene, hydrogen, and comonomers are controlled to maintain a constant composition target. The ethylene concentration is controlled to maintain a constant ethylene partial pressure. The hydrogen / ethylene flow ratio is well controlled to maintain a stable melt index of the final polymer. The concentration of all gases is measured using an online gas chromatograph to ensure a constant composition in the circulating gas stream. The continuous additive is mixed with the makeup stream as a 2% by weight solution in isopentane, used as a carrier solvent, and fed at a rate of 0.06–0.12 kg / h.

[0052] Using purified nitrogen as the carrier gas, the solid catalyst was directly injected into the fluidized bed reaction zone. The injection rate was adjusted to maintain a constant yield. The resulting polymer was semi-continuously discharged from the reaction zone into a constant-volume chamber via a series of valves. The obtained polymer was purged to remove any volatile hydrocarbons and subsequently treated with humidified nitrogen to deactivate any trace amounts of residual catalyst. The polymer product was thus obtained.

[0053] The method conditions used in the embodiments are presented in Table 1.

[0054] Table 1

[0055]

[0056] The material properties of the polymers produced in each embodiment are presented in Table 2.

[0057] Table 2

[0058] Ex1 Ex2 Ex3 Ex4 Ex5 Melt mass flow rate MFR2 (g / 10min) 1.10 1.13 0.95 1.10 1.24 MFR21 (g / 10min) 42.26 42.94 32.08 43.85 23.99 MIR(MFR2 / MFR21) 38.42 38.00 33.77 39.86 19.35 <![CDATA[Density (kg / m 3 )]]> 919.6 920.5 918.0 917.9 921.2 <![CDATA[Apparent density (kg / m 3 )]]> 340 339 374 389 385 Ash content (ppm) 460 520 430 450 228 Average particle size (mm) 0.489 0.480 0.454 0.470 0.594 Fine particles (%) 0.20 0.20 0.30 0.20 0.40 <![CDATA[M n (kg / mol)]]> 8 8 9 7 32 <![CDATA[M w (kg / mol)]]> 135 110 110 110 124 <![CDATA[M z (kg / mol)]]> 1000 770 370 640 297 <![CDATA[M w / M n ]]> 15.8 14.3 12.6 16.3 3.8 <![CDATA[M z / M w ]]> 7.8 7.0 3.2 5.5 2.4 SCB( / 1000C) 16.2 17.2 17.4 17.8 14.5 SCB ( / 1000C) at 10K 12.17 9.43 14.48 13.11 13.63 SCB at 100K ( / 1000C) 16.08 15.99 17.32 17.79 14.89 SCB ( / 1000C) at 500K 22.53 22.61 21.09 22.02 16.85 SCB ratio 1.85 2.40 1.46 1.68 1.24 C6 (mol%) 3.5 3.7 3.7 3.8 3.1 <![CDATA[T c (℃)]]> 104.1 102.5 101.2 102.7 109.7 <![CDATA[T m (℃)]]> 117.8 118.1 115.5 116.7 124.2 Crystallinity (wt%) 39.4 41.2 35.7 27.6 46.8 a-TREF < 30 (wt%) 4.2 4.5 4.7 1.5 7.2 a-TREF 30-94 (wt%) 89.0 86.8 94.8 93.7 65.0 a-TREF > 94% (by weight) 6.8 8.7 0.5 4.8 27.8 <![CDATA[CEF T of Peak 1 max (℃)]]> 75.4 75.0 74.2 73.1 76.5 CEF dW / dt (wt%) of peak 1 2.20 2.31 2.97 2.78 1.03 <![CDATA[CEF T of Peak 2 max (°C)]]> 94.7 94.3 93.2 93.2 99.4 CEF dW / dt (wt%) of peak 2 4.72 4.07 3.38 3.48 9.31

[0059] in:

[0060] - The melt mass flow rate was determined according to ASTM D1238-20 at a temperature of 190°C with loads of 2.16 kg (MFR2) and 21.6 kg (MFR21);

[0061] - The density was determined according to ASTM D1505-18;

[0062] - The bulk density was determined according to ASTM D1895-17;

[0063] - The ash content was determined according to ASTM D5630-13;

[0064] - Average particle size is determined by measuring the weight fraction of particles collected on a series of American standard sieves;

[0065] - The amount of fine particles is determined as the percentage by weight of particles passing through a 120-mesh standard sieve;

[0066] -weight-average molecular weight (M w Number-average molecular weight (M) n ) and z-average molecular weight (M z This was determined according to ASTM D6474 (2012);

[0067] -SCB was determined by GPC-IR; the SCB at 10K is M w SCB at 10,000 g / mol; SCB at 100 K is M w SCB at 100,000 g / mol; SCB at 500 K is M w =500,000 g / mol; SCB ratio = SCB at 500 K / SCB at 10 K;

[0068] -C6 content is used 13 C10 NMR was measured on a Bruker Avance 500 spectrometer equipped with a cryogenically cooled probe operating at 125 °C, wherein the sample was dissolved in C2D2Cl4 containing DBPC as a stabilizer at 130 °C.

[0069] - Crystallization temperature (T) c ), melting temperature (T) m The crystallinity was determined according to ASTM D3418-08, after recording two thermal cycles, using the data from the second cycle.

[0070] -a-TREF<30 indicates the fraction of polymer eluted in a-TREF at a temperature range of ≤30.0°C according to the method presented below, expressed as a wt%, and indicates the amorphous fraction of the polymer, calculated by subtracting the a-TREF 30-94 and a-TREF>94 ​​fractions from 100.0 wt%.

[0071] -a-TREF 30-94 indicates the fraction of polymer eluted in a-TREF in a temperature range of >30.0 and ≤94.0 °C, expressed as % by weight, and indicates the branching fraction of the polymer;

[0072] -a-TREF>94 ​​indicates the fraction of polymer eluted in a-TREF in a temperature range of >94.0 and <140°C, expressed as a percentage by weight, and represents the linear fraction of the polymer.

[0073] -CEF T of Peak 1 max It is the peak temperature (°C) of the first peak detected according to the CEF method defined below;

[0074] -CEF T of Peak 2 max It is the peak temperature (°C) of the second peak detected according to the CEF method defined below;

[0075] - The CEF dW / dt of peak 1 is the weight fraction (wt%) of the eluted fraction at the first peak, detected according to the CEF method defined below; and

[0076] - The CEF dW / dt of peak 2 is the weight fraction (wt%) of the eluted fraction at the second peak, as detected by the CEF method defined below.

[0077] Attached image description: Figure 1 The distribution of short-chain branching of the polymers of Examples 1-5, as determined by the SCB analysis method disclosed above, is presented. It can be observed that the polymers of Examples 1-4 according to the invention have higher SCB incorporation at higher molecular weights than Comparative Example 5, which is also reflected by a higher SCB ratio. The polymers of Examples 1-4 thus exhibit improved melt processability and mechanical properties, particularly in the production of films, such as those produced by blown film production or by cast film production. Figure 2 The α-TREF elution profiles of the polymers of Examples 1-5 obtained according to the methods described below are presented. Figure 3 The CEF curves of the polymers of Examples 1-5 obtained according to the method described above are presented. Figure 4 The molecular weight distributions of Examples 1-5 obtained according to the methods described below are presented.

[0078] The molecular weight distribution of the polymer was determined by gel permeation chromatography (GPC) at 150 °C and recorded on an Agilent PL-GPC 220 chromatograph using 1,2,4-trichlorobenzene as a diluent and equipped with a PL BV-400 viscometer and an infrared detector to collect molecular weight signals.

[0079] Analytical temperature rise elution fractionation (a-TREF) was performed on each polymer generated in the above experiments. A Polymer Char Crystaf-TREF 300 instrument was used. The composition to be analyzed was dissolved in analytical grade 1,2-dichlorobenzene, filtered through a 0.2 μm filter, and allowed to crystallize in a column (2500 μl volume) containing an inert support, cooled slowly to 20 °C at a cooling rate of 0.1 °C / min. The column was equipped with an infrared detector. The crystallized polymer sample was then eluted from the column by slowly increasing the temperature of the elution solvent (1,2-dichlorobenzene) from 20 °C to 130 °C at a rate of 1 °C / min to generate an a-TREF chromatogram. Topanol (1 g / L) and Irgafos 168 (1 g / L) were used as stabilizing solvents.

[0080] The results of the a-TREF classification are presented Figure 2 In Examples 1-4, it can be observed that the major fractions eluted in the temperature range of 30-94°C; however, the polymer obtained in Example 5, included for comparative purposes, showed significantly higher fractions eluted in the temperature range of >94°C, indicating a higher crystallinity. The large fractions eluted in the 30-94°C range in Examples 1-4 indicate a more uniform comonomer distribution compared to Example 5.

[0081] Crystallization elution fractionation (CEF) analysis was performed using a Polymer Char CEF instrument according to the following methods: Monrabal B., Mayo N., Romero L., Sancho-Tello J.; Crystallization Elution Fractionation: A New Approach to Measure the Chemical Composition Distribution of Polyolefins, LCGC Europe (2011) and Monrabal B., del Hierro P.; Characterization of polypropylene-polyethylene blends by temperature rising elution and crystallization analysis fractionation, Anal. Bioanal. Chem., 399, 1557-1561 (2011). The sample was first dissolved in 1,2,4-trichlorobenzene (TCB) at 1 mg / mL for 1 hour at 160 °C. The TCB was stabilized with BHT at 1000–2000 ppm. At the end of the dissolution period, the sample was transferred from the autosampler to the injection loop using a dispenser. The contents of the loop (0.2 to 0.3 ml) are injected into the CEF column using an isocratic pump. In the column, the polymer is fractionated using two temperature cycles. During the crystallization cycle, the column temperature is reduced to 35 °C at a typical cooling rate of 1 to 5 °C / min under a continuous TCB flow within the column confinement. This solvent flow rate is calculated from the column volume, cooling rate, and the difference between the first and last temperatures during the cooling cycle, and is typically 0.01 to 0.1 ml / min. At the end of the cooling cycle, the temperature is held constant for several minutes, and the solvent flow rate is increased to the elution flow rate value (typically 1 ml / min) to allow the soluble polymer to exit the column and reach the detector. The deposited fraction is then dissolved during the elution cycle as the temperature increases from 35 °C to 160 °C at a rate of 1 to 4 °C / min. The fraction is moved from the column to the detector using a continuous TCB flow to measure its concentration. The infrared detector is located in the top oven of the instrument and maintained at a constant temperature. At the end of the elution cycle, the column is washed with fresh solvent in preparation for the injection of the next sample.

[0082] The results are presented in Figure 3The results are shown in the figure, and images comparable to those of a-TREF are displayed. For the polymers obtained from Examples 1 to 4, the major fractions are located at low crystallization temperatures of 46 to 102°C, while for the polymer obtained from Comparative Example 5, the major fractions are located at high crystallization temperatures of 88 to 109°C, indicating that the polymers obtained from Examples 1 to 4 have a more uniform comonomer distribution than the polymer obtained from Comparative Example 5.

[0083] Films were produced from the polymers of Examples 2, 3, and Comparative Example 5 to determine film properties. The polymers were processed on a Polyrema 3-layer blown film extrusion machine. Each of the three extruders operated at a screw speed of 20 rpm. In the screw extruders, the polymer powder was melt-mixed with suitable additives to produce granules. Films 50 μm thick were produced from the granules using a blow-up ratio of 2.5 and a die output of 55 kg / h on a blown film line with a 30 cm frost line height. The line was equipped with a 200 mm die, a 2.5 mm die gap, reverse traction, chilled air, thickness distribution measurement, and a back-to-back winding machine. Total production was kept constant. The barrel temperature distribution increased from 185°C at the feed section to 220°C at the die. The extrusion melt pressure applied for Examples 2 and 3 (160 bar) was lower than the pressure applied for Example 5 (170 bar), indicating better processability of the samples from Examples 2 and 3.

[0084] The following properties were measured on the membrane prepared as described above.

[0085]

Claims

1. An ethylene-α-olefin copolymer comprising a structural moiety derived from ethylene and a structural moiety derived from an α-olefin comprising 3 to 10 carbon atoms, wherein the copolymer has: The short chain branch ratio of SCBR is > 1.

40. Wherein, SCBR is defined as: SCB 500 It is in M w = 500,000 g / mol, the amount of short-chain branched SCB in the copolymer and SCB 10 It is in M w =10,000 g / mol, the amount of short chain branches of the copolymer, wherein the SCB amount is determined by GPC-IR and expressed as the number of branches per 1000 carbon atoms ( / 1000C); Short chain branch content ≥ 15.0 / 1000C; Molecular weight distribution M ≥ 10.0 w / M n M w It is the weight-average molecular weight, and M n It is the number average molecular weight, M w and M n It was determined according to ASTM D6474 (2012); and The amount of polymeric structural portions derived from α-olefins containing 3 to 10 carbon atoms, relative to the total weight of the copolymer, is ≥ 1.0 and ≤ 20.0% by weight.

2. The ethylene-α-olefin copolymer according to claim 1, wherein the copolymer has: Short chain branch ratios > 1.40 and < 5.00 for SCBR Short-chain branching content ≥ 15.0 / 1000C and ≤ 35.0 / 1000C; and Molecular weight distribution M ≥ 10.0 and ≤ 20.0 w / M n .

3. The ethylene-α-olefin copolymer according to claim 1, wherein the copolymer has: Short chain branch ratios > 1.60 and < 5.00 for SCBR, and Molecular weight distribution M ≥ 11.0 and ≤ 20.0 w / M n .

4. The ethylene-α-olefin copolymer according to claim 1, wherein the copolymer has: Short chain branch ratios > 1.80 and < 4.00 for SCBR, and Molecular weight distribution M ≥ 12.0 and ≤ 20.0 w / M n .

5. The ethylene-α-olefin copolymer according to claim 1, wherein the copolymer has: Short chain branch ratios > 2.00 and < 3.00 for SCBR, and Molecular weight distribution M ≥ 13.0 and ≤ 20.0 w / M n .

6. The ethylene-α-olefin copolymer according to claim 1, wherein the copolymer has a molecular weight ratio M of ≥ 3.

0. z / M w M z The z-average molecular weight was determined according to ASTM D6474 (2012).

7. The ethylene-α-olefin copolymer according to claim 6, wherein the copolymer has a molecular weight ratio M of ≥ 3.0 and ≤ 10.

0. z / M w M z The z-average molecular weight was determined according to ASTM D6474 (2012).

8. The ethylene-α-olefin copolymer according to claim 1 or 6, wherein the α-olefin is selected from 1-butene, 1-hexene and 1-octene.

9. The ethylene-α-olefin copolymer according to claim 1 or 6, wherein the copolymer has a concentration of ≥ 900 and ≤ 940 kg / m³. 3 The density, wherein the density is determined according to ASTM D1505-18.

10. The ethylene-α-olefin copolymer according to claim 9, wherein the copolymer has a content of ≥ 910 and ≤ 925 kg / m³. 3 The density, wherein the density is determined according to ASTM D1505-18.

11. The ethylene-α-olefin copolymer according to claim 1 or 6, wherein the copolymer has a melt mass flow rate of ≥ 0.1 and ≤ 25.0 g / 10 min at 2.16 kg and 190°C, wherein the melt mass flow rate is determined according to ASTM D1238-20.

12. The ethylene-α-olefin copolymer according to claim 1 or 6, wherein the copolymer has a melt mass flow rate of ≥ 30.0 g / 10 min at 21.0 kg and 190 °C, wherein the melt mass flow rate is determined according to ASTM D1238-20.

13. The ethylene-α-olefin copolymer of claim 12, wherein the copolymer has a melt mass flow rate of ≥ 30.0 and ≤ 100.0 g / 10 min at 21.0 kg and 190 °C, wherein the melt mass flow rate is determined according to ASTM D1238-20.

14. The ethylene-α-olefin copolymer according to claim 1 or 6, wherein the copolymer exhibits two distinct peaks in the crystallization elution fraction (CEF), wherein the first peak is present in an elution temperature range of ≥ 65°C and ≤ 80°C, and the second peak is present in an elution temperature range of ≥ 85°C and ≤ 100°C.

15. The ethylene-α-olefin copolymer according to claim 1 or 6, wherein the copolymer has an analytical temperature rise elution fractionation α-TREF distribution, such that ≥ 80.0% by weight relative to the total weight of the eluent is eluted within an elution temperature range of ≥ 30°C and ≤ 94°C.

16. The ethylene-α-olefin copolymer of claim 15, wherein the copolymer has an analytical temperature rise elution fractionation α-TREF distribution such that, in an elution temperature range of ≥ 30°C and ≤ 94°C, ≥ 80.0 and ≤ 95.0% by weight relative to the total weight of the eluent material are eluted.

17. An article comprising an ethylene-α-olefin copolymer according to any one of claims 1-16.

18. The article of claim 17, wherein the article is a film or a laminate.

19. A method for producing an ethylene-α-olefin copolymer according to any one of claims 1-16, wherein the method comprises polymerizing ethylene and an amount of α-olefin having 3 to 10 carbon atoms in the presence of a catalyst system comprising a compound according to formula I: (I) Wherein R1 is selected from C2-C10 alkyl, C6-C20 aryl, and C7-C20 aralkyl; wherein R2 is selected from H and C1-C10 alkyl; and wherein R3, R4, R5, and R6 are independently selected from H, C1-C10 alkyl, C6-C20 aryl, or C7-C20 aralkyl; and wherein R3 and R4, R4 and R5, or R5 and R6 can be connected to form a ring structure; wherein each R10 is a hydrocarbon group; wherein M is selected from Ti, Zr, and Hf; and wherein X is an anionic ligand of M.

20. The method of claim 19, wherein R1 is selected from C3-C10 alkyl groups; wherein each of R10 is a C1-C4 alkyl group; wherein M is zirconium or hafnium; wherein X is methyl, Cl, Br or I; and wherein each of R2-R6 is H.

21. The method according to claim 19, wherein M is zirconium; wherein X is methyl or Cl; wherein R10 is methyl; wherein R1 is selected from isopropyl, phenyl and 3,5-dialkyl-1-phenyl.

22. The method according to claim 19, wherein R1 is 3,5-dimethyl-1-phenyl, 3,5-diethyl-1-phenyl, 3,5-diisopropyl-1-phenyl, or 3,5-di-tert-butyl-1-phenyl.

23. The method of claim 19, wherein R1 is isopropyl.

24. The method of claim 19, wherein the catalyst system comprises the compound of formula I immobilized on a support, wherein the support is selected from talc, clay or inorganic oxide.

25. The method of claim 24, wherein the carrier is silicon dioxide, aluminum oxide, magnesium oxide, titanium oxide, or zirconium oxide.

26. The method according to claim 19 or 24, wherein the catalyst system comprises a cocatalyst compound selected from cocatalysts containing aluminum or boron.

27. The method of claim 26, wherein the cocatalyst compound is selected from aluminoxanes, alkylaluminum compounds, and alkylaluminum chlorides.

28. The method according to claim 19 or 24, wherein the method is a gas-phase polymerization, a slurry polymerization, or a solution polymerization.

29. The method of claim 28, wherein the method is a gas-phase polymerization process operated in a polymerization apparatus comprising at least one fluidized bed reactor.

30. The ethylene-α-olefin copolymer according to any one of claims 1-16 is used to improve melt processability in the production of films by blown film production or by cast film production.

Images