Olefin polymerization process
By using a specific combination of support materials, metallocene compounds, cocatalysts and antistatic agents in the olefin polymerization process, the reactor fouling problem of the metallocene catalyst system is solved, olefin polymerization with high productivity and high monomer conversion rate is achieved, and polymers with desired properties are produced.
Patent Information
- Application Number
- CN202480012337.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-03-10
- Filing Date
- 2024-03-04
- Publication Date
- 2025-09-19
AI Technical Summary
Existing metallocene catalyst systems have reactor fouling problems in olefin polymerization processes, making it difficult to achieve high productivity and high monomer conversion, and it is also difficult to produce polymers with desired properties such as density and molecular weight distribution.
The catalyst system is prepared by using a catalyst system comprising a support material, a metallocene compound, a co-catalyst and an antistatic agent through a reaction under specific composition and process conditions, wherein the support material is preferably porous silica, the metallocene compound is [2,2'-bis(2-indenyl)biphenyl]zirconium dichloride, the co-catalyst is methylaluminoxane, and the antistatic agent is a mixture of hydrocarbons, benzenesulfonic acid derivatives and quaternary ammonium compounds in specific proportions.
Efficient olefin polymerization is achieved, reactor fouling is avoided, polymer productivity and monomer conversion are improved, and polymers with desired properties, such as polyethylene with high molecular weight and uniform molecular weight distribution, can be produced.
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Abstract
Description
Technical Field
[0001] The present invention relates to a process for polymerizing olefins. Background Art
[0002] As is well known, polymers produced from olefins are the most versatile polymer materials available. They can be produced economically with high and consistent product quality and, by varying, inter alia, the polymerization conditions and the raw material formulation, in a wide variety of grades, each of which meets specific application requirements and is suitable for the production of a wide variety of articles.
[0003] Specific polymers prepared from olefins include polyethylene and polypropylene. Polyethylene or polypropylene can be homopolymers of ethylene or propylene, respectively, or copolymers. Polyethylene copolymers can be produced, for example, using other monomers known as comonomers, including α-olefins, particularly α-olefins having 3 to 10 carbon atoms. Such α-olefins containing 3 to 10 carbon atoms can be selected, for example, from propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, and 4-methyl-1-pentene. Particularly suitable compounds to be used as comonomers are 1-butene, 1-hexene, and 1-octene. Polypropylene copolymers can be produced, for example, using other monomers known as comonomers, including ethylene or α-olefins containing 4 to 10 carbon atoms. Such α-olefins containing 4 to 10 carbon atoms can be selected, for example, from 1-butene, 1-pentene, 1-hexene, 1-octene, and 4-methyl-1-pentene. Particularly suitable compounds to be used as comonomers are ethylene, 1-butene, and 1-hexene.
[0004] One particular aspect of olefin polymerization that influences the properties of the polymer produced and the efficiency of the polymerization process is the catalyst system used in the polymerization.
[0005] A particular family of catalysts that may be suitable for use in the production of polyethylene by catalytic polymerization processes are the so-called single-site catalysts, a well-known group of which are the catalysts known as metallocene catalysts. While such catalysts are widely used in the manufacture of polyethylene products, there is a continuing desire to develop catalysts that allow the production of polymers having desired properties, such as desired density, molecular weight distribution (MMD), and molecular weight distribution (MWD). w / M n ) and high molecular weight M w A catalyst system for producing polyethylene which can simultaneously polymerize at a high productivity, a high monomer conversion per amount of catalyst supplied, and wherein reactor fouling due to excessive heat generation is prevented. Summary of the Invention
[0006] This is now achieved by a process for polymerizing olefins, which comprises reacting olefins in the presence of a catalyst system, wherein the catalyst system comprises a support material which carries:
[0007] a. Metallocene compounds;
[0008] b. a promoter; and
[0009] c. Antistatic agent;
[0010] Wherein, the metallocene compound is a compound according to formula (I)
[0011]
[0012] in:
[0013] Z is a moiety selected from ZrX2, HfX2 or TiX2, wherein X is selected from the group consisting of halogen, alkyl, aryl and aralkyl;
[0014] R2 is a bridging moiety containing at least one sp2 hybridized carbon atom, preferably R2 is a substituted or unsubstituted methylene, 1,2-phenylene or 2,2'-biphenylene moiety; and
[0015] Each of R1, R1', R3, R3', R4, R4', R5 and R5' is hydrogen or a hydrocarbon moiety containing 1 to 20 carbon atoms;
[0016] Wherein, the co-catalyst is an organoaluminum compound;
[0017] and
[0018] Wherein, the antistatic agent is an antistatic composition comprising the following:
[0019] (a) hydrocarbon portion;
[0020] (b) a portion of a benzenesulfonic acid derivative; and
[0021] (c) a quaternary ammonium compound portion.
[0022] For example, the metallocene compound can be selected from [o-bis(4-phenyl-2-indenyl)-benzene]zirconium dichloride, [o-bis(5-phenyl-2-indenyl)-benzene]zirconium dichloride, [o-bis(2-indenyl)benzene]zirconium dichloride, [o-bis(2-indenyl)benzene]hafnium dichloride, [o-bis(1-methyl-2-indenyl)-benzene]zirconium dichloride, [2,2'-bis(2-indenyl)biphenyl]zirconium dichloride and [2,2'-bis(2-indenyl)biphenyl]hafnium dichloride, preferably the metallocene compound is [2,2'-bis(2-indenyl)biphenyl]zirconium dichloride.
[0023] Preferably, in the metallocene compound, X is a monovalent anionic group selected from the group consisting of halogen, C1-C20 hydrocarbon group or C1-C20 alkoxy group, preferably X is a methyl group, Cl, Br or I, most preferably methyl or Cl.
[0024] It is also preferred that, in the metallocene compound, Z is a moiety selected from the group consisting of ZrCl2, HfCl2 and TiCl2.
[0025] For example, the cocatalyst can be an organoaluminum compound or a non-coordinating anion compound. Preferably, the cocatalyst is a compound selected from the following: methylaluminoxane, perfluorophenylborane, triethylammonium tetrakis(pentafluorophenyl)borate, triphenylcarbonium tetrakis(pentafluorophenyl)borate, trimethylsilyltetrakis(pentafluorophenyl)borate, 1-pentafluorophenyl-1,4-dihydroborabene, tributylammonium-1,4-bis(pentafluorophenyl)borabene and triphenylcarbonium-1-methylborabene. More preferably, the cocatalyst is methylaluminoxane.
[0026] The antistatic composition preferably comprises ≥50.0 and ≤95.0 wt % relative to the total weight of the antistatic composition, more preferably ≥50.0 and ≤85.0 wt %, even more preferably ≥50.0 and ≤75.0 wt %, yet even more preferably ≥50.0 and ≤70.0 wt % of hydrocarbon portion (a). Preferably, the hydrocarbon portion (a) is composed of a mixture of hydrocarbons containing 4 to 11 carbon atoms. Preferably, the hydrocarbon portion (a) is composed of a mixture of hydrocarbons with a boiling point of ≥-20° C. and ≤190° C. The mixture of hydrocarbons may comprise normal alkanes, isoalkanes, cyclic hydrocarbons or mixtures thereof. The mixture of hydrocarbons may comprise ≥75.0 wt %, preferably ≥80.0 wt %, more preferably ≥85.0 wt %, even more preferably ≥90.0 wt %, yet even more preferably ≥95.0 wt % of saturated hydrocarbons, relative to the total weight of the mixture of hydrocarbons.
[0027] The antistatic composition preferably comprises ≤ 10.0 wt. %, more preferably ≥ 0.5 and ≤ 10.0 wt. %, even more preferably ≥ 1.0 and ≤ 7.5 wt. %, and even more preferably ≥ 2.5 and ≤ 7.5 wt. % of a portion of a benzenesulfonic acid derivative relative to the total weight of the antistatic composition. Portion (b) of the benzenesulfonic acid derivative may, for example, comprise a 4-alkylbenzenesulfonic acid compound.
[0028] Part (b) of the benzenesulfonic acid derivative may, for example, comprise or consist of a compound of formula (II) or a mixture thereof:
[0029]
[0030] wherein R1 is an alkyl moiety containing ≥10 and ≤13 carbon atoms.
[0031] Preferably, the compound of formula (II) comprises a benzenesulfonic acid moiety and an alkyl moiety comprising ≥10 and ≤13 carbon atoms, wherein the alkyl moiety is bound to the benzene moiety of the benzenesulfonic acid moiety at position 4 and to the sulfonic acid moiety at position 1. Preferably, the alkyl moiety is bound to the benzene moiety via a secondary carbon atom of the alkyl moiety.
[0032] In a preferred embodiment, the compound of formula (II) is a compound of formula (III):
[0033]
[0034] wherein each of R2 and R3 is independently a hydrocarbon moiety comprising ≥1 and ≤11 carbon atoms, and wherein the sum of the carbon atoms of R2 and R3 together is ≥9 and ≤12. Preferably, each of R2 and R3 is independently an alkyl moiety comprising ≥1 and ≤11 carbon atoms, and the sum of the carbon atoms of R2 and R3 together is ≥9 and ≤12. More preferably, each of R2 and R3 is independently a linear alkyl moiety comprising ≥1 and ≤11 carbon atoms, and the sum of the carbon atoms of R2 and R3 together is ≥9 and ≤12.
[0035] The antistatic composition preferably comprises ≤ 2.5 wt. %, more preferably ≥ 0.1 and ≤ 2.5 wt. %, even more preferably ≥ 0.5 and ≤ 2.5 wt. %, yet even more preferably ≥ 1.0 and ≤ 2.5 wt. % of fraction (c) of quaternary ammonium compounds relative to the total weight of the antistatic composition.
[0036] Part (c) of the quaternary ammonium compound preferably comprises a quaternary ammonium compound comprising a cationic moiety and an anionic moiety.
[0037] Part (c) of the quaternary ammonium compound preferably comprises or consists of a compound comprising a cationic moiety of formula (IV) or a mixture thereof:
[0038]
[0039] wherein each of R1 and R2 is the same and is selected from methyl, ethyl, propyl or butyl moieties, preferably both R1 and R2 are methyl moieties; and
[0040] wherein each of R3 and R4 is independently an alkyl moiety containing ≥8 and ≤18 carbon atoms.
[0041] Part (c) of the quaternary ammonium compound preferably comprises or consists of a compound comprising an anionic moiety selected from nitrite, chloride, anion, hydroxide and carbonate, preferably nitrite.
[0042] Preferably, part (c) of the quaternary ammonium compound comprises or consists of a compound according to formula (V):
[0043]
[0044] Wherein, R5 is selected from NO2 - 、Cl - 、F - OH - and 1 / 2(CO3 2- ), preferably NO2 - ,
[0045] and
[0046] wherein each of R1 and R2 is the same and is selected from methyl, ethyl, propyl or butyl moieties, preferably both R1 and R2 are methyl moieties; and
[0047] wherein each of R3 and R4 is independently an alkyl moiety containing ≥8 and ≤18 carbon atoms.
[0048] Particularly preferably, part (c) of the quaternary ammonium compound comprises or consists of a compound according to formula (V) wherein R5 is NO2 - , each of R1 and R2 is a methyl group, and each of R3 and R4 is independently an alkyl moiety containing ≥8 and ≤18 carbon atoms.
[0049] In a preferred embodiment, the antistatic composition may, for example, comprise:
[0050] (a) ≥50.0 and ≤95.0 wt. %, preferably ≥50.0 and ≤75.0 wt. % hydrocarbon fraction;
[0051] (b) ≥ 0.5 and ≤ 10.0 wt. % of a portion of a benzenesulfonic acid derivative; and
[0052] (c) a fraction of ≥ 0.1 and ≤ 2.5 wt. % of quaternary ammonium compounds.
[0053] In a further preferred embodiment, the antistatic composition may, for example, comprise
[0054] (a) ≥50.0 and ≤95.0 wt. %, preferably ≥50.0 and ≤75.0 wt. % hydrocarbon fraction;
[0055] (b) ≥ 0.5 and ≤ 10.0 wt. % of a portion of a benzenesulfonic acid derivative; and
[0056] (c) a fraction of ≥ 0.1 and ≤ 2.5 wt. % of a quaternary ammonium compound;
[0057] Therein, the hydrocarbon portion (a) consists of a mixture of hydrocarbons containing 4 to 11 carbon atoms, preferably having a boiling point ≥-20°C and ≤190°C, and preferably including normal alkanes, isoalkanes, cyclic hydrocarbons or mixtures thereof.
[0058] In a further preferred embodiment, the antistatic composition may, for example, comprise
[0059] (a) ≥50.0 and ≤95.0 wt. %, preferably ≥50.0 and ≤75.0 wt. % hydrocarbon fraction;
[0060] (b) ≥ 0.5 and ≤ 10.0 wt. % of a portion of a benzenesulfonic acid derivative; and
[0061] (c) a fraction of ≥ 0.1 and ≤ 2.5 wt. % of a quaternary ammonium compound;
[0062] wherein part (b) of the benzenesulfonic acid derivative comprises or consists of a compound of formula (III) or a mixture thereof, wherein each of R2 and R3 is independently a straight-chain alkyl moiety containing ≥1 and ≤11 carbon atoms, and the sum of the carbon atoms of R2 and R3 together is ≥9 and ≤12.
[0063] In a further preferred embodiment, the antistatic composition may, for example, comprise
[0064] (a) ≥50.0 and ≤95.0 wt. %, preferably ≥50.0 and ≤75.0 wt. % hydrocarbon fraction;
[0065] (b) ≥ 0.5 and ≤ 10.0 wt. % of a portion of a benzenesulfonic acid derivative; and
[0066] (c) a fraction of ≥ 0.1 and ≤ 2.5 wt. % of a quaternary ammonium compound;
[0067] wherein part (c) of the quaternary ammonium compound comprises or consists of a compound according to formula (V) wherein R5 is NO2 - , each of R1 and R2 is a methyl group, and each of R3 and R4 is independently an alkyl moiety containing ≥8 and ≤18 carbon atoms.
[0068] Specifically, the antistatic composition may, for example, comprise:
[0069] (a) ≥50.0 and ≤95.0 wt. %, preferably ≥50.0 and ≤75.0 wt. % hydrocarbon fraction;
[0070] (b) ≥ 0.5 and ≤ 10.0 wt. % of a portion of a benzenesulfonic acid derivative; and
[0071] (c) a fraction of ≥ 0.1 and ≤ 2.5 wt. % of a quaternary ammonium compound;
[0072] wherein the hydrocarbon portion (a) consists of a mixture of hydrocarbons containing 4 to 11 carbon atoms, preferably having a boiling point of ≥-20°C and ≤190°C, and preferably including normal alkanes, isoalkanes, cyclic hydrocarbons or mixtures thereof; and
[0073] wherein part (b) of the benzenesulfonic acid derivative comprises or consists of a compound of formula (III) or a mixture thereof, wherein each of R2 and R3 is independently a straight-chain alkyl moiety containing ≥1 and ≤11 carbon atoms, and the sum of the carbon atoms of R2 and R3 together is ≥9 and ≤12.
[0074] More specifically, the antistatic composition may, for example, comprise:
[0075] (a) ≥50.0 and ≤95.0 wt. %, preferably ≥50.0 and ≤75.0 wt. % hydrocarbon fraction;
[0076] (b) ≥ 0.5 and ≤ 10.0 wt. % of a portion of a benzenesulfonic acid derivative; and
[0077] (c) a fraction of ≥ 0.1 and ≤ 2.5 wt. % of a quaternary ammonium compound;
[0078] wherein the hydrocarbon portion (a) consists of a mixture of hydrocarbons containing 4 to 11 carbon atoms, preferably having a boiling point of ≥-20°C and ≤190°C, and preferably including normal alkanes, isoalkanes, cyclic hydrocarbons or mixtures thereof; and
[0079] wherein part (c) of the quaternary ammonium compound comprises or consists of a compound according to formula (V) wherein R5 is NO2 - , each of R1 and R2 is a methyl group, and each of R3 and R4 is independently an alkyl moiety containing ≥8 and ≤18 carbon atoms.
[0080] More specifically, the antistatic composition may, for example, comprise:
[0081] (a) ≥50.0 and ≤95.0 wt. %, preferably ≥50.0 and ≤75.0 wt. % hydrocarbon fraction;
[0082] (b) ≥ 0.5 and ≤ 10.0 wt. % of a portion of a benzenesulfonic acid derivative; and
[0083] (c) a fraction of ≥ 0.1 and ≤ 2.5 wt. % of a quaternary ammonium compound;
[0084] wherein the portion (b) of the benzenesulfonic acid derivative comprises or consists of a compound of formula (II) or a mixture thereof, wherein each of R2 and R3 is independently a linear alkyl moiety containing ≥1 and ≤11 carbon atoms, and the sum of the carbon atoms of R2 and R3 together is ≥9 and ≤12; and
[0085] wherein part (c) of the quaternary ammonium compound comprises or consists of a compound according to formula (V) wherein R5 is NO2 - , each of R1 and R2 is a methyl group, and each of R3 and R4 is independently an alkyl moiety containing ≥8 and ≤18 carbon atoms.
[0086] Even more specifically, the antistatic composition may, for example, comprise, relative to the total weight of the antistatic composition,
[0087] (a) ≥50.0 and ≤95.0 wt. %, preferably ≥50.0 and ≤75.0 wt. % hydrocarbon fraction;
[0088] (b) ≥ 0.5 and ≤ 10.0 wt. % of a portion of a benzenesulfonic acid derivative; and
[0089] (c) a fraction of ≥ 0.1 and ≤ 2.5 wt. % of a quaternary ammonium compound;
[0090] wherein the hydrocarbon portion (a) consists of a mixture of hydrocarbons containing 4 to 11 carbon atoms, preferably having a boiling point of ≥-20°C and ≤190°C, and preferably including normal alkanes, isoalkanes, cyclic hydrocarbons or mixtures thereof;
[0091] wherein the portion (b) of the benzenesulfonic acid derivative comprises or consists of a compound of formula (III) or a mixture thereof, wherein each of R2 and R3 is independently a linear alkyl moiety containing ≥1 and ≤11 carbon atoms, and the sum of the carbon atoms of R2 and R3 together is ≥9 and ≤12; and
[0092] wherein part (c) of the quaternary ammonium compound comprises or consists of a compound according to formula (V) wherein R5 is NO2 - , each of R1 and R2 is a methyl group, and each of R3 and R4 is independently an alkyl moiety containing ≥8 and ≤18 carbon atoms.
[0093] In the catalyst system of the present invention, the support material can be, for example, selected from silica, alumina, magnesia, titania, zirconia, clay, zeolite, polystyrene, polyethylene, polypropylene, polyvinyl chloride, polycarbonate, polyketone, polyvinyl alcohol, polymethyl methacrylate, cellulose and graphite, preferably the support material is silica. Preferably, the support material is a porous support material, preferably porous silica. More preferably, the support material has an average particle size of 1 to 120 μm, more preferably 20 to 80 μm, even more preferably 40 to 50 μm. The pore volume of the support is preferably ≥0.5 and ≤3.0 cm 3 / g. Preferably, the surface area of the support material is ≥50 and ≤500m 2 / g. The silica that can be used as a support for the catalyst system is preferably dehydrated and then used to prepare the catalyst system. Preferably, the supported material has a particle size of 10 to 120 μm, ≥0.5 and ≤3.0 cm 3 / g pore volume ≥50 and ≤500m 2 / g of surface area of silica, as determined according to ISO 9276-2 (2014).
[0094] The catalyst system according to the present invention can be produced, for example, using a process comprising the following steps:
[0095] (i) in a reaction vessel, adding a support material to a certain amount of an organic hydrocarbon liquid, preferably toluene, and stirring to form a suspension, preferably wherein the support material is pre-dehydrated;
[0096] (ii) in a separate container, preparing an activated metallocene by mixing the metallocene and the cocatalyst in a quantity of an organic hydrocarbon liquid, preferably toluene;
[0097] (iii) adding a mixture comprising the activated metallocene obtained according to (ii) to the suspension obtained according to (i), and subjecting the reaction mixture obtained to a heat treatment, preferably at a temperature of ≥ 80°C, more preferably ≥ 80°C and ≤ 120°C, and for a time of preferably ≥ 2.5 hours, more preferably ≥ 2.5 and ≤ 6.0 hours;
[0098] (iv) in another separate container, mixing the co-catalyst and the antistatic agent in a certain amount of organic hydrocarbon liquid, preferably toluene;
[0099] (v) adding the mixture obtained in (iv) to the reaction mixture obtained from (iii), and subjecting the reaction mixture obtained to a heat treatment, preferably at a temperature ≥ 80°C, more preferably ≥ 80°C and ≤ 120°C, for a time ≥ 0.5 and ≤ 2.0 hours; and
[0100] (vi) drying the reaction product obtained in (v).
[0101] Preferably, after step (iii) but before step (v), a further amount of a co-catalyst assistant is added to the reaction mixture obtained from (iii).
[0102] Preferably, each of steps (i), (ii) and (iv) is carried out at a temperature of ≤60°C, preferably ≤50°C, more preferably ≥10°C and ≤30°C, and the heat treatment in steps (iii) and (v) is carried out at a temperature of ≥80°C and ≤120°C.
[0103] The organic hydrocarbon liquid may for example be selected from heptane, hexane, isopentane and toluene, preferably the hydrocarbon solvent is toluene. Preferably, the organic hydrocarbon liquid used in each of the steps of the process is the same, most preferably toluene.
[0104] In a particular embodiment, the present invention also relates to a catalyst system according to the invention, wherein the catalyst system is prepared according to the process according to the invention.
[0105] The invention will now be illustrated by the following non-limiting examples.A number of synthesis experiments of the catalyst system as well as a number of polymerisation experiments were performed.
[0106] Material handling
[0107] During the experiment, all materials were handled in a nitrogen atmosphere using Schlenk techniques or nitrogen-filled glove boxes. Nitrogen and isopentane were dried over a bed of molecular sieves. All other solvents were first dried over molecular sieves and sodium / potassium amalgam. In the preparation of the catalyst system, the temperature was controlled within 0.5°C of the set temperature in a silicone oil bath with stirring. During the ethylene polymerization experiments, scavenger A0 was used, which was prepared by diluting the commercial product AXION PA 4276 available from Lanxess 1.6 times in hexane. Continuity aid A1 was used in some fluidized bed ethylene polymerization experiments, which was prepared by diluting AXION PA 4276 25 times in isopentane. Chimassorb 944 was dried at 80°C under vacuum for 12 hours.
[0108] Materials used
[0109] The materials used in the experiments are listed in Table 1 below.
[0110] Table 1: Materials
[0111]
[0112] Synthesis of catalyst system, method A
[0113] A number of supported metallocene catalyst systems were prepared according to the following method. Unless otherwise stated below, the amount and type of each material used in the synthesis is presented in Table 2.
[0114] The support was pre-dehydrated at 600° C. for 4 hours. In a glove box under a nitrogen atmosphere, 2.5 g of the pre-dehydrated support was placed in a 100 ml two-necked Schlenk flask, and 15 ml of toluene was added at room temperature. After shaking, a suspension was obtained.
[0115] In a 25 ml vial, 0.035 g of the metallocene was activated by mixing it with 12.5 ml of a 10 wt% solution of the cocatalyst in toluene at room temperature in a glove box, also under nitrogen atmosphere, for 10 min. The activated metallocene was then added to the suspension.
[0116] In another 25 ml vial, the given amounts of co-catalyst and antistatic agent were mixed in 10 ml of toluene at room temperature in the glove box, also under nitrogen atmosphere, for 10 min and then also added to the suspension.
[0117] The suspension was then heated to 95°C and held at this temperature for 5 hours. The product was then dried at 75°C under vacuum to obtain a supported catalyst system, which was isolated as a free-flowing powder. The supported catalyst system contained 0.16% by weight of Zr and 14.0% by weight of Al, which translated into a molar ratio of Al to Zr of approximately 296.
[0118] Table 2: Material formulation of the catalyst system synthesized according to Method A
[0119] experiment A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 Antistatic agent type - AA1 AA1 AA1 AA2 AA2 AA2 AA3 AA3 AA3 Antistatic agent (g) - 0.158 0.308 0.617 0.009 0.017 0.035 0.006 0.012 0.025 Co-catalyst additive (g) - - - - 0.010 0.020 0.039 0.013 0.025 0.049
[0120] Synthesis of catalyst system, method B
[0121] A number of supported metallocene catalyst systems were prepared according to the following method. Unless otherwise stated below, the amount and type of each material used in the synthesis is presented in Table 3.
[0122] The support was pre-dehydrated at 600° C. for 4 hours. In a glove box under a nitrogen atmosphere, 2.5 g of the pre-dehydrated support was placed in a 100 ml two-necked Schlenk flask, and 15 ml of toluene was added at room temperature. After shaking, a suspension was obtained.
[0123] In a 25 ml vial, 0.035 g of the metallocene was activated by mixing it with 12.5 ml of a 10 wt% solution of the cocatalyst in toluene at room temperature in a glove box, also under nitrogen atmosphere, for 10 min. The activated metallocene was then added to the suspension.
[0124] The suspension was then heated to 95°C and maintained at this temperature for 4 hours.
[0125] In another 25 ml vial, the given amounts of co-catalyst and antistatic agent were mixed in 10 ml of toluene at room temperature in the glove box, also under nitrogen atmosphere, for 10 min and then also added to the suspension still at 95°C.
[0126] The suspension was then held at 95° C. for another hour. The product was then dried at 75° C. under vacuum to obtain a supported catalyst system, which was isolated as a free-flowing powder. The supported catalyst system contained 0.16% by weight of Zr and 14.0% by weight of Al, which translated into a molar ratio of Al to Zr of approximately 296.
[0127] Table 3: Material formulation of the catalyst system synthesized according to Method B
[0128] experiment B1 B2 B3 B4 Antistatic agent type AA1 AA1 AA2 AA2 Antistatic agent (g) 0.308 0.617 0.017 0.035 Co-catalyst additive (g) - - 0.020 0.039
[0129] Synthesis of catalyst system, method C
[0130] A number of supported metallocene catalyst systems were prepared according to the following method. Unless otherwise stated below, the amount and type of each material used in the synthesis is presented in Table 4.
[0131] The support was pre-dehydrated at 600° C. for 4 hours. In a glove box under a nitrogen atmosphere, 2.5 g of the pre-dehydrated support was placed in a 100 ml two-necked Schlenk flask, and 15 ml of toluene was added at room temperature. After shaking, a suspension was obtained.
[0132] In a 25 ml vial, 0.035 g of the metallocene was activated by mixing it with 12.5 ml of a 10 wt% solution of the cocatalyst in toluene at room temperature in a glove box, also under nitrogen atmosphere, for 10 min. The activated metallocene was then added to the suspension.
[0133] The suspension is then heated to 95°C and maintained at this temperature for 4 hours. 0.0074 g of co-catalyst promoter in 10 ml of toluene are subsequently added to the suspension at 95°C and maintained at 95°C for a further 10 min.
[0134] In another 25 ml vial, the given amounts of co-catalyst and antistatic agent as in Table 4 were mixed in 10 ml of toluene at room temperature in the glove box, also under nitrogen atmosphere, for 10 min and then also added to the suspension still at 95°C.
[0135] The suspension was then held at 95° C. for another hour. The product was then dried at 75° C. under vacuum to obtain a supported catalyst system, which was isolated as a free-flowing powder. The supported catalyst system contained 0.16% by weight of Zr and 14.0% by weight of Al, which translated into a molar ratio of Al to Zr of approximately 296.
[0136] Table 4: Material formulation of the catalyst system synthesized according to Method C
[0137] experiment C1 C2 C3 C4 Antistatic agent type AA1 AA1 AA2 AA2 Antistatic agent (g) 0.308 0.617 0.017 0.035 Co-catalyst additive (g) - - 0.020 0.039
[0138] Synthesis of catalyst system, method D
[0139] A number of supported metallocene catalyst systems were prepared according to the following method. Unless otherwise stated below, the amount and type of each material used in the synthesis is presented in Table 5.
[0140] A 3-liter autoclave reactor equipped with a heating / cooling control unit and a mechanical stirring system was baked out at 150°C under nitrogen flow for 2 hours and then cooled to 30°C.
[0141] The support was pre-dehydrated at 600° C. for 4 hours. 150 g of the pre-dehydrated support was charged into a reactor, and then 750 ml of toluene was added at room temperature and stirred to form a suspension.
[0142] The metallocene was activated by mixing 2.065 g of the metallocene with 737 ml of a 10 wt% solution of the cocatalyst in toluene at 50° C. for 30 min. The activated metallocene was then added to the reactor with stirring.
[0143] The suspension was then heated to 95°C and maintained at this temperature for 4 hours.
[0144] In a 250 ml vial, the given amounts of co-catalyst and antistatic agent as in Table 5 were mixed in 100 ml of toluene at room temperature in a glove box, also under nitrogen atmosphere, for 10 min to form an antistatic / co-catalyst mixture.
[0145] In Examples D1 and D3, the antistatic agent / cocatalyst co-agent mixture was added directly to the autoclave reactor after the 4-hour heat treatment as described above.The reaction mixture in the autoclave reactor was maintained at 95°C for another hour with stirring.
[0146] The product was then dried at 75°C under vacuum to obtain a supported catalyst system which was isolated as a free-flowing powder. The supported catalyst system contained 0.18 wt% Zr and 14.0 wt% Al.
[0147] In Examples D2 and D4, after the 4-hour heat treatment described above, 0.44 g of the promoter-promoter in 50 ml of toluene was charged directly into the reactor and maintained at 95° C. for 10 minutes with stirring. The antistatic agent / promoter-promoter mixture was then added to the autoclave reactor. The reaction mixture in the autoclave reactor was maintained at 95° C. for another hour with stirring.
[0148] The product was then dried at 75°C under vacuum to obtain a supported catalyst system which was isolated as a free-flowing powder. The supported catalyst system contained 0.18 wt% Zr and 14.0 wt% Al.
[0149] Table 5: Material formulation of the catalyst system synthesized according to Method D
[0150] experiment D1 D2 D3 D4 Antistatic agent type AA1 AA1 AA2 AA2 Antistatic agent (g) 18.08 18.08 1.02 1.02 Co-catalyst additive (g) - - 1.16 1.16
[0151] Example E: Polymer Synthesis Experiment - Batch
[0152] A set of polymerization experiments were carried out at a batch reactor scale using the catalyst systems prepared according to Methods A to D above.
[0153] A 1.6 stainless steel reactor vessel equipped with a propeller stirrer and a heating / cooling control unit was heated to 110°C for 2 hours under a nitrogen flow of 100 g / h. Afterwards, the reactor was pressurized with nitrogen and subsequently purged with ethylene. This purge cycle was repeated three times.
[0154] The reactor was then cooled to 88°C under ethylene pressurized to 1000 kPa. After venting, 4 ml of scavenger A0 was added via a co-catalyst injection pump. Nitrogen was introduced to maintain a nitrogen pressure of 800 kPa. Ethylene was then introduced into the reactor under mass flow control to maintain an ethylene pressure of 1000 kPa in the reactor.
[0155] After reaching a stable temperature and pressure level, 30 mg of the catalyst system specified in each polymerization example in Table 6 below was injected via a catalyst injection pump and the reaction was started. After 1 hour, the ethylene supply was stopped and the reactor was cooled to 40°C. After venting, the reactor was opened. The polyethylene product obtained was collected in a sample tray and dried at ambient temperature under atmospheric pressure.
[0156] The results of batch polymerization experiment E are presented in Table 6 below.
[0157] Table 6: Catalyst system used and polymerization results from Experiment E.
[0158]
[0159] In the reaction of Experiment E1, some sheeting and lump formation occurred in the reactor. No sheeting or lump formation occurred in Experiments E2-E18.
[0160] It has been observed that when the catalyst system according to the invention is used, the desired high polyethylene yield and productivity can be observed while avoiding the formation of sheets and lumps in the reactor. Furthermore, it has been observed that the addition of an antistatic agent during the synthesis with the catalyst system according to the invention, i.e. after first subjecting the suspension of silica and activated metallocene to a certain heating time, influences the productivity in the polyethylene synthesis.
[0161] Example F: Polymer Synthesis Experiment - Fluidized Bed Polymerization
[0162] The supported catalyst systems prepared in Experiments D1 to D4 were tested in a continuous gas-phase fluidized bed reactor having an internal diameter of 45 cm and a reaction zone height of 140 cm. The bed of polymer particles in the reaction zone was maintained in a fluidized state by supplying a recycle gas stream that served as a fluidizing medium and a heat sink for absorbing the exothermic heat generated in the reaction zone.
[0163] The reactor was maintained at a constant temperature of 87° C. and a constant ethylene pressure of 2.17 MPa. Ethylene and 1-hexene were used as reactants for the polymerization. These materials were supplied as a make-up stream. Prior to charging the reactor, 60 ppm by weight of a continuity aid, A1, was added to the make-up stream.
[0164] The catalyst system composition in solid form is injected directly into the reaction zone of a fluidized bed reactor using purified nitrogen as a carrier gas. The injection rate is adjusted to maintain a constant polymerization rate of approximately 10 kg / h. The produced polymer is discharged semi-continuously from the reactor via a series of valves into a fixed-volume chamber. The product thus obtained is purged to remove any volatile hydrocarbons and then treated with humidified nitrogen to deactivate any traces of residual catalyst composition.
[0165] In Table 7 below, the specifications of the catalysts and feeds used in Experiments F1 to F4 and the properties of the polymers obtained are presented.
[0166] Table 7: Catalyst system and feed used and polymer properties from Experiment F.
[0167] experiment F1 F2 F3 F4 catalyst D1 D2 D3 D4 Ethylene (mol%) 48.38 48.88 48.88 48.38 Hexene (mol%) 5.8 6.0 5.9 5.7 Residual ash content (ppm) 100 100 100 100 Melt mass flow rate (2.16kg / 190℃) (g / 10min) 1.0 1.1 0.85 1.0 <![CDATA[Density (kg / m 3 )]]> 919 919 919 918 <![CDATA[Bulk density (kg / m 3 )]]> 430 425 438 460 Average particle size (mm) 0.88 0.87 0.72 0.90 Fine particles (%) 0.02 0.19 0.37 0.30
[0168] The polymer properties of the products of Experiments F1-F4 were determined using the following methods:
[0169] ●Residual ash content is measured according to ISO 3451-1(2019) at 600°C for 4 hours.
[0170] • Melt mass flow rate is measured according to ISO 1133-1 (2011) at 190°C and 21.6 kg load.
[0171] ●Density is measured according to ISO 1183-1(2019).
[0172] • Bulk density was measured according to ASTM D1895-96 (2010).
[0173] ● Average particle size is determined according to ISO 13320 (2009) as D 50 .
[0174] • The fraction of fine particles is determined according to the method of ASTM D1921 (2006) as the weight % of the material passing through a 125 μm sieve.
Claims
1. A process for polymerizing olefins, comprising reacting olefins in the presence of a catalyst system, wherein the catalyst system comprises a support material carrying: a. Metallocene compounds; b. a promoter; and c. Antistatic agent; in, The metallocene compound is a compound according to formula (I): in: Z is a moiety selected from ZrX2, HfX2 or TiX2, wherein X is selected from the group consisting of halogen, alkyl, aryl and aralkyl; R2 is a bridging moiety containing at least one sp2 hybridized carbon atom, preferably R2 is a substituted or unsubstituted methylene, 1,2-phenylene or 2,2'-biphenylene moiety; and Each of R1, R1', R3, R3', R4, R4', R5 and R5' is hydrogen or a hydrocarbon moiety containing 1 to 20 carbon atoms; Wherein, the co-catalyst is an organoaluminum compound; and Wherein, the antistatic agent is an antistatic composition comprising the following: (a) hydrocarbon portion; (b) a portion of a benzenesulfonic acid derivative; and (c) a quaternary ammonium compound portion.
2. The method according to claim 1, wherein the metallocene compound is selected from [o-bis(4-phenyl-2-indenyl)-benzene]zirconium dichloride, [o-bis(5-phenyl-2-indenyl)-benzene]zirconium dichloride, [o-bis(2-indenyl)benzene]zirconium dichloride, [o-bis(2-indenyl)benzene]hafnium dichloride, [o-bis(1-methyl-2-indenyl)-benzene]zirconium dichloride, [2,2'-bis(2-indenyl)biphenyl]zirconium dichloride and [2,2'-bis(2-indenyl)biphenyl]hafnium dichloride, preferably the metallocene compound is [2,2'-bis(2-indenyl)biphenyl]zirconium dichloride.
3. The method according to claim 1, wherein X is a monovalent anionic group selected from the group consisting of halogen, C1-C20 hydrocarbon group or C1-C20 alkoxy group, preferably wherein X is a methyl group, Cl, Br or I, most preferably methyl or Cl.
4. The method according to any one of claims 1 or 3, wherein Z is a moiety selected from the group consisting of ZrCl2, HfCl2 and TiCl2.
5. The process according to any one of claims 1 to 4, wherein the cocatalyst is methylaluminoxane.
6. The process according to any one of claims 1 to 5, wherein the hydrocarbon portion is a mixture of hydrocarbons comprising 4 to 11 carbon atoms, preferably having a boiling point ≥ -20°C and ≤ 190°C, more preferably wherein the hydrocarbon portion is a mixture of hydrocarbons comprising normal alkanes, isoalkanes, cyclic hydrocarbons or mixtures thereof.
7. The method according to any one of claims 1 to 6, wherein the portion of the benzenesulfonic acid derivative comprises or consists of a compound of formula (II) or a mixture thereof: in, R1 is an alkyl moiety containing ≥10 and ≤13 carbon atoms.
8. The method according to any one of claims 1 to 7, wherein the antistatic composition comprises ≤ 10.0 wt.-%, preferably ≥ 0.5 and ≤ 10.0 wt.-% of benzenesulfonic acid derivatives relative to the total weight of the antistatic composition.
9. The method according to any one of claims 1 to 8, wherein the portion of the quaternary ammonium compound comprises or consists of a compound according to formula (V): in, R5 is selected from NO2 - 、Cl - 、F - OH - and 1 / 2(CO3 2- ), preferably NO2 - , and wherein each of R1 and R2 is the same and is selected from methyl, ethyl, propyl or butyl moieties, preferably both R1 and R2 are methyl moieties; and wherein each of R3 and R4 is independently an alkyl moiety containing ≥8 and ≤18 carbon atoms.
10. The method according to any one of claims 1 to 9, wherein the antistatic composition comprises a fraction of ≤ 2.5 wt.-%, preferably ≥ 0.1 and ≤ 2.5 wt.-% of the quaternary ammonium compound relative to the total weight of the antistatic composition.
11. The process according to any one of claims 1 to 10, wherein the support material is selected from the group consisting of silica, alumina, magnesia, titania, zirconia, clay, zeolite, polystyrene, polyethylene, polypropylene, polyvinyl chloride, polycarbonate, polyketone, polyvinyl alcohol, polymethyl methacrylate, cellulose and graphite, preferably wherein the support material is silica.
12. The process according to any one of claims 1 to 11, wherein the olefin is one or more selected from ethylene, propylene, 1-butene, 1-hexene and 1-octene, preferably wherein the process is a polymerization process of ethylene alone or as a mixture with 1-butene, 1-hexene or 1-octene.
13. The process according to any one of claims 1 to 12, wherein the catalyst system is produced via a process comprising the steps of: (i) adding the support material to a certain amount of organic hydrocarbon liquid, preferably toluene, in a reaction vessel, and stirring to form a suspension, preferably wherein the support material is pre-dehydrated; (ii) in a separate container, preparing an activated metallocene by mixing the metallocene and the cocatalyst in a certain amount of an organic hydrocarbon liquid, preferably toluene; (iii) adding a mixture comprising the activated metallocene obtained according to (ii) to the suspension obtained according to (i), and subjecting the reaction mixture obtained to a heat treatment, preferably at a temperature of ≥ 80°C, more preferably ≥ 80°C and ≤ 120°C, and for a time of preferably ≥ 2.5 hours, more preferably ≥ 2.5 and ≤ 6.0 hours; (iv) in another separate container, mixing the co-catalyst promoter and the antistatic agent in a certain amount of organic hydrocarbon liquid, preferably toluene; (v) adding the mixture obtained in (iv) to the reaction mixture obtained from (iii), and subjecting the reaction mixture obtained to a heat treatment, preferably at a temperature ≥ 80°C, more preferably ≥ 80°C and ≤ 120°C, for a time ≥ 0.5 and ≤ 2.0 hours; and (vi) drying the reaction product obtained in (v); Preferably wherein after step (iii) but before step (v) a further amount of said co-catalyst assistant is added to the reaction mixture obtained from (iii).
14. The method according to claim 13, wherein each of steps (i), (ii) and (iv) is carried out at a temperature of ≤ 60°C, preferably ≤ 50°C, more preferably ≥ 10°C and ≤ 30°C, and wherein the heat treatment in steps (iii) and (v) is carried out at a temperature of ≥ 80°C and ≤ 120°C.
15. The process according to any one of claims 1 to 14, wherein the process is a gas phase process, preferably a fluidized bed gas phase polymerization process, preferably wherein the polymerization is carried out at a temperature of ≥70°C and ≤100°C and a pressure of ≥1.0 and ≤3.0 MPa.