PROCESS FOR THE PREPARATION OF A MULTIMODAL POLYETHYLENE
20240002560 · 2024-01-04
Inventors
- Georgy KIPIANI (Kulloo, FI)
- Jyrki KAUHANEN (Kulloo, FI)
- Felice DE SANTIS (Linz, AT)
- Marja MUSTONEN (Kulloo, FI)
- Matthias HOFF (Linz, AT)
- Kalin SIMEONOV (Linz, AT)
- Kimmo HAKALA (Helsinki, FI)
- Jarkko HASSINEN (Kulloo, FI)
- Maria RANIERI (Kulloo, FI)
- Esko SAIKKONEN (Kulloo, FI)
- Tiina HÄMÄLÄINEN (Kulloo, FI)
- Stefan POLLHAMMER (Linz, AT)
- Pascal CASTRO (Kulloo, FI)
- Irfan SAEED (Kulloo, FI)
- Kalle KALLIO (Kulloo, FI)
Cpc classification
C08F2420/07
CHEMISTRY; METALLURGY
International classification
Abstract
The invention provides a process for the preparation of a multimodal ethylene polymer in a multistage process in the presence of a catalyst comprising a complex of formula (lx) wherein each X is a sigma donor ligand; each Het is independently a monocyclic or multicyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from O, N or S; L is a carbon, silicon or germanium based divalent bridge in which one or two backbone atoms link the ligands; M is Ti, Zr or Hf; each R.sub.1 is the same or different and is a linear CMO alkyl group, or linear CHO alkoxy, each n is 0 to 3; each R.sub.2 is the same or different and is a C.sub.1-10 alkyl group, C.sub.1-10 alkoxy group or Si(R)3 group; each R is the same or different and is C.sub.1-10 alkyl or phenyl group optionally substituted by 1 to 3 C1-6 alkyl groups; and eachp is 0 to 3;
##STR00001##
Claims
1. A process for the preparation of a multimodal ethylene polymer comprising: (I) polymerising ethylene and optionally at least one C4-10 alpha olefin comonomer in a first stage in the presence of a racemic metallocene catalyst comprising: (i) a complex of formula (Ix) ##STR00046## wherein each X is a sigma donor ligand; each Het is independently a monocyclic or multicyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from O, N or S; L is a carbon, silicon or germanium based divalent bridge in which one or two backbone atoms link the ligands; M is Ti, Zr or Hf; each R.sub.1 is the same or different and is a linear C.sub.1-10 alkyl group, or linear C.sub.1-10 alkoxy, each n is 0 to 3; each R.sub.2 is the same or different and is a C.sub.1-10 alkyl group, C.sub.1-10 alkoxy group or Si(R).sub.3 group; each R is the same or different and is C.sub.1-10 alkyl or phenyl group optionally substituted by 1 to 3 C.sub.1-6 alkyl groups; and each p is 0 to 3; (ii) a cocatalyst which comprises a compound of a group 13 element; and optionally (iii) a support; so as to form a first polyethylene component; (II) polymerising ethylene and optionally at least one C4-10 alpha olefin comonomer in a second stage in the presence of the product of step (I) so as to form a second component.
2. The process as claimed in claim 1, wherein: said first polyethylene component forms 30 to 70 wt % of said ethylene polymer; said second component forms 30 to 70 wt % of said ethylene polymer; and wherein said multimodal ethylene polymer has a density of 900 to 980 kg/m.sup.3, an MFR.sub.2 in the range of 0.01 to 50 g/10 min.
3. A process for the preparation of a multimodal polyethylene polymer comprising: (I) contacting a solid support with a solution of a cocatalyst comprising a compound of a group 13 element and a racemic metallocene complex of formula (Ix) ##STR00047## wherein each X is a sigma donor ligand; each Het is independently a monocyclic or multicyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from O, N or S; L is a carbon, silicon or germanium based divalent bridge in which one or two backbone atoms link the ligands; M is Ti, Zr or Hf; each R.sub.1 is the same or different and is a linear C.sub.1-10 alkyl group, or linear C.sub.1-10 alkoxy, each n is 0 to 3; each R.sub.2 is the same or different and is a C.sub.1-10 alkyl group, C.sub.1-10 alkoxy group or Si(R).sub.3 group; each R is C.sub.1-10 alkyl or phenyl group optionally substituted by 1 to 3 C.sub.1-6 alkyl groups; and each p is 0 to 3; so as to form a supported catalyst; (II) polymerising ethylene and optionally at least one C4-10 alpha olefin comonomer in a first stage in the presence of said supported catalyst so as to form a first polyethylene component (e.g. a lower molecular weight component); (III) polymerising ethylene and optionally at least one C4-10 alpha olefin comonomer in a second stage in the presence of the product of step (I) so as to form a second polyethylene component (e.g. a higher molecular weight component).
4. A process for the preparation of a multimodal polyethylene polymer comprising: (I) contacting a solid support with a solution of a cocatalyst comprising a compound of a group 13 element; so as to form a cocatalyst impregnated support; (II) contacting said cocatalyst impregnated support with a racemic metallocene complex of formula (Ix) ##STR00048## wherein each X is a sigma donor ligand; each Het is independently a monocyclic or multicyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from O, N or S; L is a carbon, silicon or germanium based divalent bridge in which one or two backbone atoms link the ligands; M is Ti, Zr or Hf; each R.sub.1 is the same or different and is a linear C.sub.1-10 alkyl group, or linear C.sub.1-10 alkoxy, each n is 0 to 3; each R.sub.2 is the same or different and is a C.sub.1-10 alkyl group, C.sub.1-10 alkoxy group or Si(R)3 group; each R is the same or different and is C.sub.1-10 alkyl or phenyl group optionally substituted by 1 to 3 C.sub.1-6 alkyl groups; and each p is 0 to 3; so as to form a supported catalyst; (III) polymerising ethylene and optionally at least one C4-10 alpha olefin comonomer in a first stage in the presence of said supported catalyst so as to form a first polyethylene component (e.g. a lower molecular weight component); (IV) polymerising ethylene and optionally at least one C4-10 alpha olefin comonomer in a second stage in the presence of the product of step (I) so as to form a second polyethylene component (e.g. a higher molecular weight component).
5. The process as claimed in claim 1, wherein the cocatalyst is an aluminoxane.
6. The process as claimed in claim 1, wherein the support is a porous inorganic support.
7. The process as claimed in claim 1, wherein the complex of formula (Ix) is C2 symmetric.
8. The process as claimed in claim 1, wherein each X is independently a hydrogen atom, a halogen atom, C.sub.1-6-alkyl, C.sub.1-6-alkoxy group, amido, phenyl or benzyl group.
9. The process as claimed in claim 1, wherein L is -R.sub.2C, -R.sub.2CCR.sub.2-, -R.sub.2Si, -R.sub.2SiSiR.sub.2-, -R.sub.2Ge-, wherein each R is independently a hydrogen atom or a C.sub.1-C.sub.20-hydrocarbyl group optionally containing one or more heteroatoms of Group 14-16 of the periodic table or fluorine atoms, or optionally two R groups taken together can form a ring, preferably wherein L is -R.sub.2Si; wherein each R is independently a C.sub.1-C.sub.10-alkyl, C.sub.2-10 alkenyl, C.sub.5-6-cycloalkyl, C.sub.1-10-alkyl-O-C.sub.1-10 alkyl, benzyl or phenyl group.
10. The process as claimed in claim 1, wherein R.sub.1 is a linear C.sub.1-6-alkyl group.
11. The process as claimed in claim 1, wherein the first polymerisation stage is preceded by a prepolymerisation step.
12. The process as claimed in claim 1, wherein at least one comonomer is present in the first stage or second stage.
13. The process as claimed in claim 1, wherein said multimodal polyethylene polymer comprises 1-butene, 1-hexene, 1-octene or a mixture thereof.
14. The process as claimed in claim 1, wherein the first stage takes place in the slurry phase and the second stage in the gas phase.
15. The process as claimed in claim 1, wherein L is a (RdRe)Si group, (RdRe)Ge or (RdRe)CH.sub.2; Rd is a C.sub.1-10 alkyl group, C.sub.5-10-cycloalkyl, benzyl or phenyl; and Re is a C.sub.2-10 alkenyl group.
16. The process as claimed in claim 1, wherein: each X is independently a hydrogen atom, a halogen atom, a C.sub.1-6-alkyl, C.sub.1-6-alkoxy group, amido, phenyl or benzyl group; each Het is independently a monocyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from O or S; L is -R.sub.2Si, wherein each R is independently C.sub.1-20 hydrocarbyl or C.sub.1-10 alkyl substituted with alkoxy having 1 to 10 carbon atoms; M is Ti, Zr or Hf; each R.sub.1 is the same or different and is a linear C.sub.1-6 alkyl group or linear C.sub.1-6 alkoxy group; each n is 1 to 2; each R.sub.2 is the same or different and is a C.sub.1-6 alkyl group, C.sub.1-6 alkoxy group or Si(R).sub.3 group; each R is the same or different and is C.sub.1-10 alkyl or phenyl group optionally substituted by 1 to 3 C.sub.1-6 alkyl groups; and each p is 0 to 1.
17. The process as claimed in claim 1, wherein said complex is: ##STR00049##
18. The process as claimed in claim 1, wherein the first stage takes place in the slurry phase and the second stage in the gas phase and the activity of the catalyst in the gas phase is higher than the slurry phase.
19. (canceled)
20. The process as claimed in claim 1, wherein: each X is independently a hydrogen atom, a halogen atom, a C.sub.1-6-alkyl, C.sub.1-6-alkoxy group, amido, phenyl or benzyl group; each Het is independently a monocyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from O or S; L is -R.sub.2Si, wherein each R is independently C1-10 alkyl, C3-8 cycloalkyl or C.sub.2-10 alkenyl; M is Ti, Zr or Hf; each R.sub.1 is the same or different and is a linear C.sub.1-6 alkyl group; each n is 1 to 2; each R.sub.2 is the same or different and is a Si(R).sub.3 group; each R is C.sub.1-10 alkyl or phenyl group optionally substituted by 1 to 3 C.sub.1-6 alkyl groups; and each p is 0 to 1.
21. The process as claimed in claim 1, wherein the complex is of formula (VII) ##STR00050## wherein each X is a sigma donor ligand; L is a carbon, silicon or germanium based divalent bridge in which one or two backbone atoms link the ligands; each R.sub.1 is the same or different and is a linear C.sub.1-6 alkyl group; each n is 0 to 3; each R.sub.2 is the same or different and is a C.sub.1-6 alkyl group or Si(R).sub.3 group; each R is C.sub.1-10 alkyl or phenyl group optionally substituted by 1 to 3 C.sub.1-6 alkyl groups; and each p is 0 to 3.
Description
[0458] The invention will now be defined with reference to the following non-limiting examples and figures.
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EXPERIMENTAL
Analytical Methods
Catalyst Analysis
Al and Zr Content in a Solid Catalyst by ICP-OES
[0491] In a glovebox, an aliquot of the catalyst (ca. 40 mg) is weighted into a glass weighing boat using an analytical balance. The sample is then allowed to be exposed to air overnight while being placed in a steel secondary container equipped with an air intake. Then, 5 mL of concentrated (65%) Nitric acid is used to rinse the content of the boat into an Xpress microwave oven vessel (20 mL). A sample is then subjected to microwave-assisted acid digestion using MARS 6 laboratory microwave unit with ramping to 150 C. within 20 minutes and a hold phase at 150 C. for 35 minutes. The digested sample is allowed to cool down to room temperature and then transferred into a plastic 100 mL volumetric flask. Standard solutions containing 1000 mg/L Yttrium (0.4 mL) are added. The flask is then filled up with distilled water and shaken. The solution is filtered through 0.45 m Nylon syringe filters and subjected to analysis using Thermo iCAP 6300 ICP-OES and iTEVA software.
[0492] The instrument is calibrated for Al and Zr using a blank (a solution of 5% HNO.sub.3, prepared from concentrated Nitric acid) and six standards of 0.005 mg/L, 0.01 mg/L, 0.1 mg/L, 1 mg/L, 10 mg/L and 100 mg/L of Al and Zr in solutions. The solutions contain 5% HNO.sub.3 (from concentrated nitric acid), 4 mg/L of Y standard in distilled water. Plastic volumetric flasks are used. Curvilinear fitting and 1/concentration weighting are used for the calibration curves. Immediately before analysis, the calibration is verified and adjusted (instrument re-slope function) using the blank and the 10 mg/L Al and Zr standard which has 4 mg/L Y and 5% HNO.sub.3, from concentrated nitric acid, in distilled water. A quality control sample (QC: 1 mg/L Al; 2 mg/L Zr and 4 mg/L Y in a solution of 5% HNO.sub.3, from concentrated nitric acid, in distilled water) is run to confirm the re-slope. The QC sample is also run at the end of a scheduled analysis set.
[0493] The content for Zr is monitored using the 339.198 nm line. The content of Al is monitored via the 394.401 nm line. The Y 371.030 nm is used as the internal standard. The reported values are calculated back to the original catalyst sample using the original mass of the catalyst aliquot and the dilution volume.
Volatiles Content in a Solid Catalyst by GC-MS
[0494] A test portion of 50-80 mg of catalyst powder is weighed accurately into a 20 mL headspace vial under inert atmosphere. The vial is capped using an aluminium cap with PTFE/silicone septum. 1 mL of internal standard solution (50 mg Toluene-d.sub.8 and 50 mg n-Nonane in 100 mL n-Dodecane) is added into the sample vial through the septum cap using a precision micro-syringe. The same ISTD solution is used for the samples and for the calibration standard solutions.
[0495] For the calibration, a standard stock solution is prepared by weighing accurately 40 mg of each analyte component (n-Pentane, n-Heptane and Toluene) into a 20 mL volumetric flask which is filled up to the mark with ISTD stock solution. Calibration solutions with different analyte concentrations are prepared by dosing six increasing portions (0.1-1 mL) of analyte standard stock solution accurately into 20 mL headspace vials followed by addition of ISTD solution in decreasing volumes, bringing the total ISTD stock solution volume to 1.0 mL in each vial. The analyte amount in the final calibration samples ranges from 0.2 mg/mL to 2 mg/mL. For a blank 1 mL of ISTD stock solution is transferred into a 20 mL headspace vial.
[0496] The measurement is performed using an Agilent 7890B Gas Chromatograph equipped with an Agilent 7697A headspace sampler and an Agilent 5977A Mass Spectrometer Detector. The carrier gas is 99.9996% Helium. The headspace sampler oven temperature is set to 80 C. with loop and transfer line temperatures at 120 C. The vial equilibration time is 15 minutes. For sampling, the headspace sample vial is filled in the flow to pressure mode and pressurised with a flow of 20 mL/min to 172 kPa. The sampling of the loop is ramped at 138 kPa/min with final pressure of 34 kPa. The carrier gas flow in the DB-ProSteel transfer line with 0.53 mm diameter is 54 mL/min.
[0497] The gas chromatography inlet is operating in split mode. The inlet temperature is set to 280 C. and pressure to 18.236 psi, total flow is 111.9 mL/min, septum purge flow 3 mL/min and split flow 108 mL/min. The split ratio is 120:1. The inlet liner uses ultra-inert split liner with glass wool.
[0498] The separation is achieved using a ZB-XLB-HT Inferno 60 m250 m0.25 m column (Phenomenex) with a pre-column restriction capillary of 3m250 m0 m. The carrier flow in the analytical column is 1.1 mL/min. The initial oven temperature is 40 C. and the hold time is 0.1 minutes. The oven ramp consists of a first stage of 5 C./min to 60 C. and a second stage of 10 C./min to 120 C. and a third stage of 40 C./min to 250 C.
[0499] The MS detector transfer line is kept at 300 C. The MSD is operated in Electron Impact mode at 70 eV and scan mode ranging from 33-175 m/z, step size 0.1 m/z. The source temperature is 230 C. and the quadrupole temperature is set to 150 C. Threshold is set to 50 counts and electron multiplier gain factor to 1. The detector is switched off after 11.40 minutes.
[0500] The signal identities are determined by retention times (Pentane 4.5, Heptane 6.3, Toluene 7.8, Toluene-d.sub.8 7.7 and n-Nonane 10.0) and target ion m/z (Pentane 55.0, Heptane 100.0, Toluene 91.0, Toluene-d.sub.8 98.0 and n-Nonane 98.0). Additionally qualifier ions are used for confirmation of the identification (Heptane, Toluene). The target ion signals of each analyte and the internal standard are integrated and compared to calibration curve, established in the beginning of each run with the six calibration samples. The calibration curves for the response ratios are linear; sample concentration weighting is applied for pentane. A quality control sample is used in each run to verify the standardisation. The mass of the test portion is used for calculating the analyte concentration in the sample for both replicates and the result reported as the average in wt %.
Polymer Analysis and Characterisation
Polymer Melt Flow Rate (MFR)
[0501] The melt flow rate (MFR) is determined according to ISO 1133 and is indicated in g/10 min. The MFR is determined at 190 C. for PE. The load under which the melt flow rate is determined is usually indicated as a subscript, for instance, MFR.sub.2 is measured under 2.16 kg load.
[0502] Polymer Density
[0503] Determination of polymer density was performed using immersion method (Archimedean principle) following the ISO 1183-1:2012 (method A). The tests were done on disc die-cut out of compression-moulded plates. The compression moulding process parameters used were:
TABLE-US-00001 Pressure Time Temperature Hydraulic Mould PE [s] [ C.] [bar] [N/cm.sup.2] Preheating 360 180 5 7 Moulding 300 180 50 65 300 180 200 262 840 23 Cooling 15 K/min 200 262 <40 C. demoulding temperature
[0504] After compression moulding the specimens were conditioned at 232 C. and 5010% humidity for 242 h. Following the Archimedean principle, the specimen were then weighed on air and immersed in a liquid (Isododecane), whose density is lower than that of the specimen. The tests were done without the Buoyancy correction suggested in the standard.
[0505] Quantification of Microstructure by NMR Spectroscopy
[0506] Quantitative nuclear-magnetic resonance (NMR) spectroscopy was used to quantify the comonomer content of the polymer.
[0507] Quantitative .sup.13C{.sup.1H} NMR spectra recorded in the molten-state using a Bruker Avance III 500 NMR spectrometer operating at 500.13 and 125.76 MHz for .sup.1H and .sup.13C respectively. All spectra were recorded using a .sup.13C optimised 7 mm magic-angle spinning (MAS) probehead at 150 C. using nitrogen gas for all pneumatics. Approximately 200 mg of material was packed into a 7 mm outer diameter zirconia MAS rotor and spun at 4 kHz. This setup was chosen primarily for the high sensitivity needed for rapid identification and accurate quantification {klimke06, parkinson07, castignolles09}. Standard single-pulse excitation was employed utilising the NOE at short recycle delays of 3 s {pollard04, klimke06} and the RS-HEPT decoupling scheme {fillip05, griffin07}. A total of 1024 (1k) transients were acquired per spectra.
[0508] Quantitative .sup.13C{.sup.1H} NMR spectra were processed, integrated and relevant quantitative properties determined from the integrals. All chemical shifts are internally referenced to the bulk methylene signal (+) at 30.00 ppm {randall89}.
[0509] Characteristic signals corresponding to the incorporation of 1-butene were observed {randall89} and the comonomer fraction calculated as the fraction of 1-butene in the polymer with respect to all monomer in the polymer.
[0510] The amount of isolated 1-butene incorporated in EEBEE sequences was quantified using the integral of the *B2 sites [I.sub.*B2] at 39.8 ppm accounting for the number of reporting sites per comonomer:
B=I.sub.*B2
[0511] With no other signals indicative of other comonomer sequences, i.e. consecutive comonomer incorporation observed, the total 1-butene comonomer content was calculated based solely on the amount of isolated 1-butene sequences:
Btotal=B
[0512] The total mole fraction of 1-butene in the polymer was then calculated as:
fB=Btotal/(Etotal+Btotal+Htotal)
[0513] Characteristic signals corresponding to the incorporation of 1-hexene were observed {randall89} and the comonomer fraction calculated as the fraction of 1-hexene in the polymer with respect to all monomer in the polymer.
[0514] The amount isolated 1-hexene incorporated in EEHEE sequences was quantified using the integral of the *B4 sites [I.sub.*B4] at 38.2 ppm accounting for the number of reporting sites per comonomer:
H=I.sub.*B4
[0515] With no other signals indicative of other comonomer sequences, i.e. consecutive comonomer incorporation observed, the total 1-hexene comonomer content was calculated based solely on the amount of isolated 1-hexene sequences:
Htotal=H
[0516] The total mole fraction of 1-hexene in the polymer was then calculated as:
fH=Htotal/(Etotal+Btotal+Htotal)
[0517] The amount of ethylene was quantified using the integral of the bulk methylene (+) sites at 30.00 ppm. This integral included the y site as well as the 3B4 sites from 1-hexene. The total ethylene content was calculated based on the bulk integral and compensating for the observed 1-butene and 1-hexene sequences and end-groups:
E=I.sub.+/2
[0518] Characteristic signals resulting from saturated end-groups were observed. The content of such saturated end-groups was quantified using the average of the integral of the signals at 22.8 [I.sub.2S] and 32.2 ppm [I.sub.3S] assigned to the 2s and 3s sites respectively:
S=(1/2)*(I.sub.2S+I.sub.3S)
[0519] The presence of isolated comonomer units is corrected for based on the number of comonomer units and saturated end-groups present:
Etotal=E+(3/2)*B+(2/2)*H+(3/2)*S
[0520] The mole percent comonomer incorporation is calculated from the mole fraction:
B [mol %]=100*fB
H [mol %]=100*fH
[0521] The weight percent comonomer incorporation is calculated from the mole fraction:
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))
[0522] randall89
[0523] J. Randall, Macromol. Sci., Rev. Macromol. Chem. Phys. 1989, C29, 201.
[0524] klimke06
[0525] Klimke, K., Parkinson, M., Piel, C., Kaminsky, W., Spiess, H. W., Wilhelm, M., Macromol. Chem. Phys. 2006;207:382.
[0526] parkinson07
[0527] Parkinson, M., Klimke, K., Spiess, H. W., Wilhelm, M., Macromol. Chem. Phys. 2007;208:2128.
[0528] pollard04
[0529] Pollard, M., Klimke, K., Graf, R., Spiess, H. W., Wilhelm, M., Sperber, O., Piel, C., Kaminsky, W., Macromolecules 2004;37:813.
[0530] filip05
[0531] Filip, X., Tripon, C., Filip, C., J. Mag. Resn. 2005, 176, 239
[0532] griffin07
[0533] Griffin, J. M., Tripon, C., Samoson, A., Filip, C., and Brown, S. P., Mag. Res. in Chem. 2007 45, S1, S198
[0534] castignolles09
[0535] Castignolles, P., Graf, R., Parkinson, M., Wilhelm, M., Gaborieau, M., Polymer 50 (2009) 2373
Raw Materials
[0536] Pre-treated silica is a commercial synthetic amorphous silica ES757 obtained from PQ Corp. The pre-treatment refers to silica commercial calcination at 600 C. according to a conventional PO catalyst technique.
[0537] Methylaluminoxane (30 wt % MAO solution in Toluene, Axion CA 1330) was obtained from Lanxess.
[0538] Bis(1-methyl-3-n-butylcyclopentadienyl)zirconium dichloride (MC4) was commercially available as a Toluene stock solution.
[0539] Metallocene Complex Preparation
[0540] Rac-dimethylsilanediylbis[2-(5-trimethylsilylfuran-2-yl)-4,5-dimethylcyclopentadien-1-yl]zirconium dichloride (MC3).
[0541] This complex was prepared in pure stereoisomeric form according to published synthetic procedure (U.S. Pat. No. 6,326,493)
[0542] The following novel metallocenes were prepared:
[0543] Anti- and syn-methyl(pent-4-en-1-yl)silanediyl-bis[n.sup.5-2-(2-(5-trimethylsilyl)furyl)-4,5-dimethylcyclopentadienyl]zirconium dichloride (MC1, inventive and MC5, comparative)
[0544] Multi-step complex preparation method:
[0545] Bis[2-(2-(5-trimethylsilyl)furyl)-4,5-dimethylcyclopenta-2,4-dien-1-yl](methyl)pent-4-en-1-ylsilane
##STR00028##
[0546] To a cooled to 78 C. solution of 19.6 g (84.3 mmol) of 1-(2-(5-trimethylsilyl)furyl)-3,4-dimethylcyclopenta-1,3-diene in 200 ml of THF 34.7 ml (84.3 mmol) of 2.43 M .sup.nBuLi in hexanes was added. The resulting red solution was stirred for 4 h at room temperature, then cooled to 50 C., and 300 mg of CuCN was added. The obtained mixture was stirred for 15 min at 25 C., then 7.72 g (42.2 mmol) of dichloro(methyl)pent-4-en-1 -ylsilane was added in one portion. This mixture was stirred overnight at room temperature. The solvents were removed on rotary evaporator; to the dark-red residue 600 ml of dichloromethane was added, and the resulting mixture was washed with 600 ml of water. The organic layer was separated, dried over Na.sub.2SO.sub.4, filtered through a pad of silica gel 60 (40-63 um), which was additionally washed by 250 ml of dichloromethane. The combined filtrate was evaporated under reduced pressure and dried in vacuum to give 21.9 g (90%, purity ca. 75%) of the target product (a ca. 60:40 mixture of two stereoisomers) as a dark-red oil.
[0547] Anti- and syn-methyl(pent-4-en-1-yl)silanediyl-bis[n.sup.5-2-(2-(5-trimethylsilyl)furyl)-4,5-dimethylcyclopentadienyl]zirconium dichloride
##STR00029##
[0548] To a cooled to 78 C. solution of 21.85 g (ca. 28.5 mmol) of bis[2-(2-(5-trimethylsilyl)furyl)-4,5-dimethylcyclopenta-2,4-dien-1-yl](methyppent-4-en-1-ylsilane in 250 ml of ether 31.3 ml (76.1 mmol) of 2.43 M .sup.nBuLi in hexanes was added. This mixture was stirred for 4 h at room temperature, then the resulting red solution was cooled to 78 C., and 8.86 g (38.02 mmol) of ZrCl.sub.4 was added. The mixture was stirred for 20 h at room temperature (giving dark-red solution with yellow precipitate) which was then evaporated to dryness. The residue was stirred with 100 ml of hot toluene, and the formed suspension was filtered through a glass frit (G4). On the evidence of NMR spectroscopy, the filtrate included a mixture of the isomeric complexes, i.e. anti-complex and two isomeric syn-zirconocenes in a ca. 2:1:1 ratio. This filtrate was evaporated to dryness, the residue was dissolved in a mixture of 25 ml of n-hexane and 100 ml of n-pentane. Yellow solid precipitated from this solution overnight at 30 C. was filtered off (G4) and dried in vacuum. This procedure gave 3.90 g of anti-complex contaminated with syn-admixture. Recrystallization of this sample from a mixture of 10 ml of toluene and 30 ml of n-hexane gave 3.00 g of pure anti-zirconocene dichloride. The mother liquor (obtained after isolation 3.90 g sample) was evaporated to dryness, and the residue was dissolved in 100 ml of n-pentane. Yellow solid precipitated from the obtained solution overnight at 30 C. was filtered off (G4) and dried in vacuum to give 1.85 g of anti-isomer containing trace amount of one of the two syn-complexes. Finally, the mother liquor was evaporated to dryness to the state of dark foam, and this foam was then dissolved in 150 ml of n-pentane. Yellow precipitate fallen from this solution for 2 days at 30 C. was filtered off (G4), washed with 5 ml of toluene and dried in vacuum to give 2.10 g of a 45:55 mixture of anti- and syn-complexes. Recrystallization of this mixture from a mixture of n-hexane and n-pentane gave 0.23 g of one of the two syn-complexes contaminated with ca. 6% of anti-isomer. Thus, the total yield of anti- and syn-complexes was 7.85 g (37.5%). It should be noted that only one of the two syn-isomers was isolated in this reaction.
[0549] Anti-methyl(pent-4-en-1-yl)silanediyl-bis[n.sup.5-2-(2-(5-trimethylsilypfuryl)-4,5-dimethylcyclopentadienyl]zirconium dichloride (MC1).
[0550] Anal. calc. for C.sub.34H.sub.48Cl.sub.2O.sub.2Si.sub.3Zr: C, 55.55; H, 6.58. Found: C, 55.81; H, 6.70.
[0551] .sup.1H NMR (CDCl.sub.3): 6.71 (2s, 2H), 6.61 (d, J=3.2 Hz, 2H), 6.56 (d, J=3.2 Hz, 1H), 6.52 (d, J=3.2 Hz, 1H), 5.90-5.77 (m, 1H), 5.04 (dm, J=17.1 Hz, 1H), 4.98 (dm, J=10.2 Hz, 1H), 2.28-2.10 (m, 2H), 2.19 (s, 6H), 1.85-1.59 (m, 2H), 1.48 (s, 3H), 1.46 (s, 3H), 1.21 (t, J=8.4 Hz, 2H), 0.73 (s, 3H), 0.29 (s, 9H), 0.28 (s, 9H). .sup.13C{.sup.1H} NMR (CDCl.sub.3): 159.81, 159.56, 153.28, 153.20, 138.54, 138.31, 138.02, 129.57, 129.13, 128.51, 127.78, 123.06, 122.11, 121.82, 121.74, 114.96, 110.30, 110.17, 99.93, 99.75, 37.22, 22.79, 16.84, 14.47, 14.31, 14.25, 14.00, 0.42, 1.24, 1.39.
[0552] Syn-methyl(pent-4-en-1-yl)silanediyl-bis[n.sup.5-2-(2-(5-trimethylsilyl)furyl)-4,5-dimethylcyclopentadienyl]zirconium dichloride (MC5).
[0553] Anal. calc. for C.sub.34H.sub.48Cl.sub.2O.sub.2Si.sub.3Zr: C, 55.55; H, 6.58. Found: C, 55.69; H, 6.76.
[0554] .sup.1H NMR (CDCl.sub.3): 6.63 (s, 2H), 6.31 (d, J=3.2 Hz, 2H), 6.11 (d, J=3.2 Hz, 2H), 5.93-5.80 (m, 1H), 5.09 (dm, J=17.1 Hz, 1H), 5.04 (dm, J=10.2 Hz, 1H), 2.31-2.23 (m, 2H), 2.28 (s, 6H), 2.00 (s, 6H), 1.85-1.73 (m, 2H), 1.53-1.45 (m, 2H), 0.40 (s, 3H), 0.22 (s, 18H). .sup.13C{.sup.1H} NMR (CDCl.sub.3): 158.57, 152.38, 138.09, 138.06, 131.29, 129.02, 122.74, 121.42, 115.44, 110.23, 99.49, 37.28, 22.76, 16.54, 15.17, 14.32, 0.34, 1.40.
[0555] Rac-dimethylsilanediyl-bis[n.sup.5-2-(2-(5-dimethylphenylsilyl)furyl)-4,5-dimethylcyclopentadienyl]zirconium dichloride (MC2, inventive)
[0556] Multi-Step Complex Preparation:
[0557] 2-Furyl(dimethyl)phenylsilane
##STR00030##
[0558] To a solution of 25.0 g (367 mmol) of furan in 165 ml of ether, cooled in an ice bath, 123.5 ml (300 mmol) of 2.43 M .sup.nBuLi in hexanes was added dropwise over ca. 40 min. The resulting mixture was stirred for 3.5 h at room temperature, then the formed suspension was cooled to 78 C., and 50.0 ml (51.6 g, 302 mmol) of chloro(dimethyl)phenylsilane was added in one portion. The resulting mixture was stirred for 40 h at room temperature. The formed suspension was filtered through a pad of silica gel 60 (40-63 um), which was additionally washed with 350 ml of dichloromethane. The combined filtrate was evaporated under reduced pressure, and the residue was distilled in vacuum (b.p. 79 C./3-4 mm Hg) to give 56.6 g (93%) of 2-furyl(dimethyl)phenylsilane as a colourless liquid.
[0559] .sup.1H NMR (CDCl.sub.3): 7.67 (d, J=1.6 Hz, 1H), 7.58-7.53 (m, 2H), 7.38-7.33 (m, 3H), 6.67 (d, J=3.2 Hz, 1H), 6.38 (dd, J=3.2 Hz, J=1.6 Hz, 1H), 0.54 (s, 6H). .sup.13C{.sup.1H} NMR (CDCl.sub.3): 158.14, 147.11, 136.95, 133.91, 129.37, 127.85, 121.02, 109.41, 2.91.
[0560] 1-[2-(5-Dimethylphenylsilyl)furyl]-3,4-dimethylcyclopenta-1,3-diene
##STR00031##
[0561] To a cooled to 78 C. solution of 20.2 g (100 mmol) of 2-furyl(dimethyl)phenylsilane in 150 ml of THF 41.2 ml (100.1 mmol) of 2.43 M .sup.nBuLi in hexanes was added dropwise. The resulting mixture was stirred for 20 h at room temperature, then cooled to 30 C., and a solution of 11.0 g (100 mmol) of 3,4-dimethylcyclopent-2-en-1-one in 60 ml of THF was added dropwise by vigorous stirring. The resulting solution was stirred overnight at room temperature, then cooled in an ice bath, and 200 ml of 5 N HCl was added. This mixture was transferred into a separatory funnel, 600 ml of ether was added, and the obtained mixture was shaken for 1 min. The organic layer was separated, washed with 3150 ml of water, dried over Na.sub.2SO.sub.4, and then evaporated to dryness. The residue was purified by flash column chromatography on silica gel 60 (40-63 um; eluent: hexane) to give 25.9 g (88%, purity ca. 90%) of the target product as a reddish oily liquid.
[0562] .sup.1H NMR (CDCl.sub.3): 7.59-7.56 (m, 2H), 7.38-7.33 (m, 3H), 6.62 (d, J=3.2 Hz, 1H), 6.57 (br.s, 1H), 6.21 (d, J=3.2 Hz, 1H), 3.21 (s, 2H), 1.94 (s, 3H), 1.87 (s, 3H), 0.54 (s, 6H). .sup.13C{.sup.1H} NMR (CDCl.sub.3): 157.01, 156.14, 137.36, 135.34, 135.14, 133.97, 132.89, 131.37, 129.24, 127.80, 122.95, 104.15, 44.75, 13.35, 12.54, 2.75.
[0563] Bis[2-(2-(5-dimethylphenylsilyl)furyl)-4,5-dimethylcyclopenta-2,4-dien-1-yl]dimethylsilane
##STR00032##
[0564] To a cooled to 78 C. solution of 25.9 g (87.9 mmol) of 1-[2-(5-dimethylphenylsilyl)furyl]-3,4-dimethylcyclopenta-1,3-diene in 200 ml of THF 36.2 ml (88.0 mmol) of 2.43 M .sup.nBuLi in hexanes was added. The resulting dark-red solution was stirred for 3 h at room temperature, then cooled to 50 C., and 300 mg of CuCN was added. The obtained mixture was stirred for 15 min at 25 C., then 5.67 g (55.56 mmol) of dichlorodimethylsilane was added in one portion. This mixture was stirred overnight at room temperature. The solvents were removed on rotary evaporator, to the dark-red residue 700 ml of dichloromethane was added, and the resulting mixture was washed with 800 ml of water. The organic layer was separated, dried over Na.sub.2SO.sub.4, filtered through a pad of silica gel 60 (40-63 um), the latter was additionally washed with 250 ml of dichloromethane. The combined filtrate was evaporated under reduced pressure, and the residue was dried in vacuum to give 25.6 g (90%, purity ca. 80%) of the target pro-ligand (as a ca. 1:1 mixture of two stereoisomers) as a dark-red oil.
[0565] .sup.1H NMR (CDCl.sub.3): 7.57-7.46 (m, 4H), 7.39-7.26 (m, 6H), 6.59 (d, J=3.2 Hz), 6.57 (br.s) and 6.57 (d, J=3.2 Hz) {sum 4H}, 6.24 (d, J=3.2 Hz) and 6.07 (d, J=3.2 Hz) {sum 2H}, 4.07 (s) and 3.70 (s) {sum 2H}, 2.13 (s), 1.98 (s), 1.88 (s) and 1.87 (s) {sum 12H}, 0.51 (s), 0.50 (s), 0.48 (s) and 0.46 (s) {sum 12H}, 0.45 (s), 0.72 (s) and 0.78 (s) {sum 6H}.
[0566] Rac-dimethylsilanediyl-bis[n.sup.5-2-(2-(5-dimethylphenylsilyl)furyl)-4,5-dimethylcyclopentadienyl]zirconium dichloride (MC2)
##STR00033##
[0567] To a cooled to 78 C. solution of 25.6 g (ca. 39.7 mmol) of bis[2-(2-(5-dimethylphenylsilyl)furyl)-4,5-dimethylcyclopenta-2,4-dien-1-yl]dimethylsilane in 300 ml of ether 32.6 ml (79.2 mmol) of 2.43 M .sup.nBuLi in hexanes was added. This mixture was stirred overnight at room temperature, then the resulting brown suspension with a lot of white precipitate was cooled to 78 C., and 9.25 g (39.7 mmol) of ZrCl.sub.4 was added. The reaction mixture was stirred for 24 h at room temperature to give dark-red solution with yellow precipitate. The precipitate was filtered off. The filtrate was evaporated to ca. 30 ml, and then 30 ml of n-hexane was added. Yellow powder (a mixture of the target complex with LiCl) precipitated from this mixture was filtered off, washed with n-hexane, and then added to the above-isolated precipitate. Thus obtained solid was stirred with 50 ml of hot toluene (almost at reflux), and the formed suspension was filtered through a glass frit (G4). The filtrate was evaporated to ca. 25 ml, heated to ca. 60 C., and then 30 ml of n-hexane was added. Yellow powder precipitated from this solution overnight at room temperature was filtered off (G4), dried in vacuum to give 4.82 g of the target complex. The mother liquor was evaporated to ca. 5 ml, and 25 ml of hexane was added. Yellow solid precipitated from thus obtained mixture overnight at room temperature was collected (G4) and then dried in vacuum. This procedure gave extra 0.7 g of the title zirconocene. Thus, the total yield of the target rac-complex was 5.52 g (17%).
[0568] Anal. calc. for C.sub.40H.sub.46Cl.sub.2O.sub.2Si.sub.3Zr: C, 59.67; H, 5.76. Found: C, 59.95; H, 5.81.
[0569] .sup.1H NMR (CDCl.sub.3): 7.58-7.52 (m, 2H), 7.41-7.31 (m, 3H), 6.69 (s, 1H), 6.65 (d, J=3.3 Hz, 1H), 6.55 (d, J=3.3 Hz, 1H), 2.16 (s, 3H), 1.35 (s, 3H), 0.56 (s, 3H), 0.55 (s, 3H), 0.54 (s, 3H). .sup.13C{.sup.1H} NMR (CDCl.sub.3): 157.60, 154.01, 138.23, 136.56, 134.06, 129.42, 128.77, 128.18, 127.80, 123.41, 122.01, 110.19, 100.06, 14.22, 14.18, 3.34, 2.65, 3.05.
[0570] Rac- and meso-dimethylsilanediyl-bis[n.sup.5-2-(2-(5-trimethylsilyl)furyl)-4-tert-butylcyclopentadienyl]zirconium dichloride (MC6 and MC7, comparative)
[0571] Multi-Step Complex Preparation:
[0572] Ethyl 2-acetyl-5,5-dimethyl-4-oxohexanoate
##STR00034##
[0573] 12.5 g (544 mmol, 1.66 equiv.) of sodium was added to 360 ml of toluene followed by 132 ml (1.04 mol, 3.16 equiv.) of ethyl acetoacetate. A vigorous exothermic reaction with evolution of molecular hydrogen took place after a minute and subsided after ca. 10 min. The reaction mixture was then stirred for 2 h at room temperature. To the resulting heterogeneous mixture 58.8 g (329 mmol) of 1-bromo-3,3-dimethylbutan-2-one was added dropwise, and the reaction mixture was stirred overnight at room temperature. The resulting mixture was cooled in an ice bath and then treated with 400 ml of water. Further on, another 400 ml of water was added, the organic layer was separated, and the aqueous layer was extracted with 400 ml of ether. The combined organic extract was dried over Na.sub.2SO.sub.4, evaporated, and an excess of ethyl acetoacetate was removed by distillation in vacuo (b.p. 65 C./6 mm Hg) to give 79.3 g (ca. 100%) of the target product which was further used without an additional purification.
[0574] .sup.1H NMR (CDCl.sub.3): 4.19 (q, J=7.2 Hz, 2H), 4.01 (dd, J=8.3 Hz, J=5.6 Hz, 1H), 3.23 (dd, J=18.5 Hz, J=8.3 Hz, 1H), 3.02 (dd, J=18.5 Hz, J=5.6 Hz, 1H), 2.37 (s, 3H), 1.28 (t, J=7.2 Hz, 3H), 1.17 (s, 9H). .sup.13C{.sup.1H} NMR (CDCl.sub.3): 213.36, 202.49, 168.92, 61.57, 53.67, 43.77, 35.70, 30.18, 26.39, 13.95.
[0575] 3-tert-Butylcyclopent-2-en-1-one
##STR00035##
[0576] 1 L of hot water was added to 37.5 g (164.3 mmol) of ethyl 2-acetyl-5,5-dimethyl-4-oxohexanoate (prepared above). To this mixture a solution of 110 g (1.96 mol) of KOH in 500 ml of water was added dropwise over 1 h at reflux. The reaction mixture was refluxed over 8 h, cooled to room temperature, and then extracted with 3400 ml of ether. The combined extract was dried over Na.sub.2SO.sub.4, filtered through a pad of silica gel 60 (40-63 um), and then evaporated to dryness to give 18.0 g of the crude product contaminated with ca. 15% of 6,6-dimethylheptane-2,5-dione.sup.1. This crude product originated from four similar syntheses was combined and distilled in vacuum to obtain fractions with different purity of 3-tert-butylcyclopent-2-en-1-one, including the fraction of 3-tert-butylcyclopent-2-en-1-one of ca. 95% purity, which had a higher boiling point than 6,6-dimethylheptane-2,5-dione. Thus, the calculated yield of the target product (given .sup.1H NMR data of pure 3-tert-butylcyclopent-2-en-1-one) was 52.0 g (57%), and 6,6-dimethylheptane-2,5-dione8.77 g (8.5%). It was shown, that a mixture of 3-tert-butylcyclopent-2-en-1-one with diketone can be used for the subsequent synthesis of the substituted cyclopentadiene.
[0577] .sup.1H NMR (CDCl.sub.3): 5.95 (t, J=1.7 Hz, 1H), 2.67-2.63 (m, 2H), 2.44-2.40 (m, 21-1), 1.2 (s, 9H). .sup.13C{.sup.1H} NMR (CDCl.sub.3): 210.54, 191.11, 127.21, 35.41, 35.11, 28.68, 27.58.
[0578] 1-tert-Butyl-3-[2-(5-trimethylsilyl)furyl]cyclopenta-1,3-diene
##STR00036##
[0579] To a cooled to 78 C. solution of 22.2 g (158 mmol) of 2-trimethylsilylfuran in 230 ml of THF 65.2 ml (158 mmol) of 2.43 M .sup.nBuLi in hexanes was added dropwise. The resulting mixture was stirred for 7.5 h at room temperature, then cooled to 35 C., and 20.0 g of 3-tert-butylcyclopent-2-en-1-one of 89% purity [containing ca. 11% of 6,6-dimethylheptane-2,5-dione, so the added mixture contained 17.55 g (127 mmol) of 3-tert-butylcyclopent-2-en-1-one and 2.45 g (15.68 mmol) of 6,6-dimethylheptane-2,5-dione] was added in one portion. The resulting solution was stirred overnight at room temperature, then cooled in an ice bath, and 200 ml of 4 N HCl was added. This mixture was transferred into a separatory funnel, 500 ml of ether was added, and the obtained mixture was shaken for 1 min. The organic layer was separated, washed with 3200 ml of water, dried over Na.sub.2SO.sub.4, and then evaporated to dryness. The residue was purified by flash column chromatography on silica gel 60 (40-63 um; eluent: hexane) to give 27.5 g (83% based on 3-tert-butylcyclopent-2-en-1-one in a mixture) of the target product (a mixture of two double bond regioisomers in a ca. 88:12 ratio) as an orange oily liquid which spontaneously solidified at room temperature. .sup.1 The increase in reaction time to 11 hours led to a decrease in the 6,6-dimethylheptane-2,5-dione content to 10% without reducing the mass of the resulting mixture
[0580] .sup.1H NMR (CDCl.sub.3): 6.83 (m, 1H), 6.59 (d, J=3.2 Hz, 1H), 6.27 (d, J=3.2 Hz, 1H), 5.89 (q, J=1.7 Hz, 1H), 3.27 (t, J=1.4 Hz, 2H), 1.2 (s, 9H), 0.28 (s, 9H). .sup.13C{.sup.1H} NMR (CDCl.sub.3): 158.86, 157.62, 156.36, 137.02, 127.12, 121.29, 121.01, 104.93, 40.01, 32.20, 29.70, 1.48.
[0581] Bis[2-(2-(5-trimethylsilyl)furyl)-4-tert-butylcyclopenta-2,4-dien-1-yl]dimethylsilane
##STR00037##
[0582] To a cooled to 50 C. solution of 25.5 g (97.9 mmol) of 1-tert-butyl-3-[2-(5-trimethylsilyl)furyl]cyclopenta-1,3-diene in 200 ml of THF 40.3 ml (97.9 mmol) of 2.43 M .sup.nBuLi in hexanes was added. The resulting dark-red solution was stirred for 3.5 h at room temperature, then cooled to 50 C., and 300 mg of CuCN was added. The obtained mixture was stirred for 15 min at 25 C., then 6.32 g (49.0 mmol) of dichlorodimethylsilane was added in one portion. This mixture was stirred overnight at room temperature. The solvents were removed on rotary evaporator, to the dark-red residue 600 ml of dichloromethane was added, and the resulting mixture was washed with 800 ml of water. The organic layer was separated, dried over Na.sub.2SO.sub.4, filtered through a pad of silica gel 60 (40-63 um), which was additionally washed with 250 ml of dichloromethane. The combined filtrate was evaporated under reduced pressure. The resulting dark-red oil was dissolved in 500 ml of n-hexane, the obtained suspension was filtered through a pad of silica gel 60 (40-63 um), which was additionally washed with 350 ml of n-hexane. The filtrate was evaporated and dried in vacuum to give 25.4 g (90%, purity ca. 90%) of bis[2-(2-(5-trimethylsilyl)furyl)-4-tert-butylcyclopenta-2,4-dien-1-yl]dimethylsilane (a ca. 1:1 mixture of two stereoisomers) as a light-red oil.
[0583] .sup.1H NMR (CDCl.sub.3): 6.85-6.82 (m, 2H), 6.58 (d, J=3.2 Hz) and 6.57 (d, J=3.2 Hz) {sum 2H}, 6.29 (d, J=3.2 Hz) and 6.27 (d, J=3.2 Hz) {sum 2H}, 6.17 (m) and 6.11 (m) {sum 2H}, 3.87 (d, J=1.2 Hz) and 3.66 (d, J=1.2 Hz) {sum 2H}, 1.24 (s) and 1.19 (s) {sum 18H}, 0.23 (s) and 0.22 (s) {sum 18H}, 0.36 (s), 0.44 (s) and 0.50 (s) {sum 6H}. .sup.13C{.sup.1H} NMR (CDCl.sub.3): 158.41, 158.40, 156.50, 156.43, 156.09, 155.78, 138.14, 138.03, 126.69, 126.59, 124.53, 123.75, 121.37 (two resonances), 104.90, 104.82, 48.75, 47.78, 32.30, 32.24, 30.41, 30.38, 1.43, 1.46, 4.29, 6.52, 6.76.
[0584] Rac- and meso-dimethylsilanediyl-bis[n.sup.5-2-(2-(5-trimethylsilyl)furyl)-4-tert-butylcyclopentadienyl]zirconium dichloride
##STR00038##
[0585] To a cooled to 78 C. solution of 25.4 g (44.0 mmol) of bis[2-(2-(5-trimethylsilyl)furyl)-4-tert-butylcyclopenta-2,4-dien-1-yl]dimethylsilane in 350 ml of ether 36.2 ml (88.0 mmol) of 2.43 M .sup.nBuLi in hexanes was added. This mixture was stirred overnight at room temperature, then the resulting red solution was cooled to 78 C., and 10.3 g (44.2 mmol) of ZrCl.sub.4 was added. The reaction mixture was stirred for 24 h at room temperature to give dark-red solution with yellow precipitate. This mixture was evaporated to dryness. The residue was stirred with 200 ml of hot toluene, and the formed suspension was filtered through a glass frit (G4). This filtrate was evaporated to ca. 100 ml. Light-orange precipitate fallen from this solution for 3 h at room temperature was washed with 10 ml of toluene and then dried in vacuum. This procedure gave 9.70 g (30%) of pure rac-complex. The mother liquor was evaporated to ca. 10 ml, the formed solution was heated to ca. 60 C., and then 30 ml of n-hexane was added. Yellow powder (meso-complex contaminated with 5% of rac-isomer) and red crystals (a ca. 4:1 mixture of rac- and meso-comp) precipitated from this solution overnight at room temperature were filtered off (G4) to give 9.30 g of meso-zirconocene contaminated with ca. 15% of rac-complex. The mother liquor was evaporated almost to dryness, and the residue was dissolved in 40 ml of n-hexane. Yellow solid precipitated from the resulting mixture overnight at room temperature was filtered off (G4) and dried in vacuum. This procedure gave 3.50 g of a mixture of meso-/rac-complexes in a 67:43 ratio. Thus, the total yield of rac- and meso-zirconocene dichloride was 22.5 g (69%). To the yellow powder from the second fraction (9.30 g, yellow powder with red crystals) 120 ml of n-hexane was added, the yellow powder was shortly dissolved, and the red crystals were immediately filtered off (G3). The filtrate was evaporated to dryness, and the residue was recrystallized from a mixture of 7 ml of toluene and 15 ml of n-hexane to give 4.50 g (14%) of pure meso-dimethylsilanediyl-bis[n.sup.5-2-(2-(5-trimethylsilyl)furyl)-4-tert-butylcyclopentadienyl]zirconium dichloride.
[0586] Rac-dimethylsilanediyl-bis[n.sup.5-2-(2-(5-trimethylsilyl)furyl)-4-tert-butylcyclopentadienyl]-zirconium dichloride (MC6).
[0587] Anal. calc. for C.sub.34H.sub.50Cl.sub.2O.sub.2Si.sub.3Zr: C, 55.40; H, 6.84. Found: C, 55.64; H, 7.02.
[0588] .sup.1H NMR (CDCl.sub.3): 6.75 (d, J=2.5 Hz, 2H), 6.67 (d, J=3.3 Hz, 2H), 6.54 (d, J=3.3 Hz, 2H), 5.54 (d, J=2.5 Hz, 2H), 1.26 (s, 18H), 0.84 (s, 6H), 0.33 (s, 18H). .sup.13C{.sup.1H} NMR (CDCl.sub.3): 159.89, 153.94, 153.36, 124.98, 123.70, 122.07, 111.58, 109.47, 103.22, 33.89, 30.16, 0.09, 1.31.
[0589] Meso-dimethylsilanediyl-bis[n.sup.5-2-(2-(5-trimethylsilyl)furyl)-4-tert-butylcyclopentadienyl]-zirconium dichloride (MC7).
[0590] Anal. calc. for C.sub.34H.sub.50Cl.sub.2O.sub.2Si.sub.3Zr: C, 55.40; H, 6.84. Found: C, 55.77; H, 7.09.
[0591] .sup.1H NMR (CDCl.sub.3): 6.82 (d, J=2.5 Hz, 2H), 6.25 (d, J=3.3 Hz, 2H), 6.07 (d, J=3.3 Hz, 2H), 5.69 (d, J=2.5 Hz, 2H), 1.35 (s, 18H), 1.04 (s, 3H), 0.74 (s, 3H), 0.28 (s, 18H). .sup.13C{.sup.1H} NMR (CDCl.sub.3): 158.44, 152.94, 152.89, 127.08, 124.46, 122.28, 111.97, 108.47, 101.59, 34.10, 30.35, 1.77, 1.36, 2.89.
Catalyst Preparation
[0592] All catalyst examples (except CE1 which was used as received), were prepared based on the described metallocene complexes MC1-MC7 using two largely different catalyst preparation methods. One-step catalyst preparation method is described in Experiment 1 section, while the two-step catalyst preparation method is described in Experiment 2 section. MC7 complex was used only in two-step preparation method.
Inventive Catalysts
[0593] Inventive catalysts IC1-1 and IC1-2 are based on anti- or rac-form MC1:
##STR00039##
[0594] Inventive catalysts IC2-1 and IC2-2 are based on rac-form MC2:
##STR00040##
[0595] Inventive catalysts IC3-1 and IC3-2 are based on rac-form MC3:
##STR00041##
Comparative Catalysts
[0596] Comparative catalyst CE1 is an alumoxane-containing silica-supported catalyst containing metallocene Bis(1-methyl-3-n-butylcyclopentadienyl)zirconium dichloride (MC4) and is based on the enhanced ActivCat activation technology from Grace, received in ready form as a slurry in mineral oil.
##STR00042##
[0597] Comparative catalysts CE2-1 and CE2-2 are based on the same Bis(1-methyl-3-n-butylcyclopentadienyl)zirconium dichloride complex MC4, similarly to CE1 catalyst, but prepared using the same procedures as other prepared catalyst examples.
[0598] Comparative catalysts CE3-1 and CE3-2 are based on the syn- or meso-form MC5:
##STR00043##
[0599] Comparative catalysts CE4-1 and CE4-2 are based on the rac-form MC6:
##STR00044##
[0600] Comparative catalyst CE5-2 is based on the meso-form MC7:
##STR00045##
Polymerisation Examples
[0601] All the inventive and comparative catalysts were tested in bench-scaR.sup.1 Ethylene copolymerisation in same conditions targeting particular gas phase split (58%), meaning that as soon as a certain designated amount of Ethylene was consumed during the slurry phase polymerisation stage, the reactor was switched to the gas phase stage, which was stopped when overall target consumption of Ethylene was reached. In cases when the gas phase split could not be reached due to low catalyst activity, the gas phase stage was terminated prematurely due to total experiment time limitations (see marked with asterisk * values in Table 1 and Table 2).
General Bench-Scale Multi-Stage Ethylene Copolymerisation Method
[0602] All polymerisations were done in a stirred autoclave with a volume of 5.3 L. The evacuated autoclave is filled with 700 g of Propane. 0.12 mmol of Triethylaluminium scavenger (0.62 mol/L solution in Heptane) is added using a stream of additional 100 g of Propane. 16 g of Ethylene and 2.7 g of 1-Butene are added and the reactor is heated up to the desired prepolymerisation temperature of 60 C. Approximately 100 mg of catalyst is weighed into a steel vial inside a glovebox and suspended in 3 mL of Heptane (8 mL in case a catalyst is an oil slurry). The vial is then attached to the polymerisation autoclave and the suspension is flushed into the reactor with 200 g of Propane.
[0603] For prepolymerisation, the reactor is stirred at 60 C. The pressure is kept constant at 21.1 barg by feeding Ethylene with a flow meter. After consumption of 10 g of Ethylene or exceeding 45 min run time, the temperature is increased to 85 C. Next, 12 mg of Hydrogen and 5.4 g of 1-Butene are fed into the reactor. In parallel, Ethylene is fed until the desired polymerisation pressure of 36.9 barg is reached.
[0604] For slurry phase polymerisation, the reactor is stirred at 85 C. The pressure is kept constant by feeding Ethylene, 1-Butene and Hydrogen in fixed ratios (Butene/Ethylene=0.035 g/g and Hydrogen/Ethylene=0.000068 g/g). After consumption of 200 g of Ethylene, the reaction is stopped by venting and evacuating the reactor.
[0605] For gas phase polymerisation, the reactor temperature is set to 75 C. It is refilled with Propane until a pressure of 10 barg is reached. 1.3 mg of Hydrogen and 10.5 g of 1-Hexene are fed into the reactor. In parallel, Ethylene is fed until the reactor pressure reaches 20 barg. During polymerisation, the pressure is kept constant by feeding Ethylene, 1-Hexene and Hydrogen in a fixed ratio (Hexene/Ethylene=0.064 g/g and Hydrogen/Ethylene=0.000038 g/g). After consumption of 278 g of Ethylene, the reaction is stopped by venting the reactor. In case of too low activity (e.g. <1 kg/(g.Math.h)), the reaction is stopped before reaching the desired Ethylene consumption.
Experiment 1: One-Step Catalyst Preparation and Polymerisation Examples
[0606] Metallocene complexes MC1-MC6 in this experiment were employed using a single step catalyst preparation procedure comprising the mixture of a metallocene and alumoxane during the impregnation. As a result, inventive catalysts IC1-1-IC3-1, as well as comparative catalysts CC2-1-CC4-1 were prepared as described in the below one-step catalyst preparation method.
General One-Step Catalyst Preparation Method
[0607] A pre-contact mixture, obtainable by dissolution of 140 mol of metallocene in Methylaluminoxane solution (14 mmol Al as 30 wt % MAO solution in Toluene) and 1.6-2.0 mL of additional Toluene, is stirred for 1-2 hours in a glass vial at room temperature in Nitrogen atmosphere. The obtained solution is then added drop-wise within 5 minutes to 2 g of pre-treated silica carrier in a glass reactor under gentR.sup.1 mechanical stirring at 10-30 C. The crude catalyst is then gently mixed for 1 hour further and left to stand for further 17 hours. The catalyst is then dried in vacuo for 30-60 minutes at 60 C.
TABLE-US-00002 TABLE 1 Bimodal multi-stage copolymerisation with inventive and comparative catalyst examples obtained using one-step catalyst preparation method. Polymerisation example IE1-1 LE2-1 IE3-1 CE1-1 CE2-1 CE3-1 CE4-1 Catalyst IC1-1 IC2-1 IC3-1 CC1 CC2-1 CC3-1 CC4-1 Metallocene in catalyst MC1 MC2 MC3 MC4 MC4 MC5 MC6 Loading Zr/SiO.sub.2, mol/g 70 70 70 70 70 70 Loading Al/SiO.sub.2, mmol/g 7 7 7 7 7 7 Loading Al/Zr ratio 100 100 100 100 100 100 Zr content, wt % 0.307 0.317 0.349 0.279 0.326 0.277 Al content, wt % 12.4 12.2 12.7 11.7 12.4 11 Al/Zr ratio, mol/mol 137 130 123 142 129 134 Volatiles content, wt % 0.51 <0.2 <0.2 1.27 <0.2 2.61 Catalyst amount used (dry basis), mg 106 105 109 94 104 104 102 SP time, min 87 171 89 83 150 127 165 GP time, min 52 48 60 73 129* 116 55* SP Activity, kgPE/(gcat .Math. h) 1.4 0.7 1.3 1.6 0.7 0.9 0.3 GP Activity, kgPE/(gcat .Math. h) 3.2 3.5 2.7 2.6 0.6 1.5 0.2 GP/SP Activity Ratio 2.4 5.1 2.1 1.6 0.9 1.6 0.8 Polymer yield, g 502 496 503 502 293 490 67* GP split, wt % 58 58 59 59 42 58 19 MFR.sub.2, g/10 min 1.0 1.0 0.6 2.2 3.0 2.5 230 Density, kg/m.sup.3 923.3 921.9 921.3 928.7 932.7 932.2 949.8 1-Butene content in polymer, wt % 1.1 1.2 1.0 0.4 0.7 0.6 0.9 1-Hexene content in polymer, wt % 4.1 4.2 4.1 4.1 2.5 3.4 2.0 1-Butene in SP material (calc.), wt % 2.6 2.9 1.8 1.1 1.2 1.3 1.1 1-Hexene in GP material (calc.), wt % 7.0 7.2 7.1 6.9 6.0 5.8 10.4
[0608] All inventive catalysts IC1-1-IC3-1 and comparative catalysts CC1, CC2-1-CC4-1 were used in copolymerisation in a multi-stage configuration comprising a prepolymerisation, slurry phase polymerisation and gas phase polymerisation. Polymerisation conditions are described above as the General bench-scale multi-stage Ethylene copolymerisation method and the corresponding copolymerisation inventive examples IE1-1-IE3-1 and comparative examples CE1-1-CE4-1 are disclosed in Table 1. Comparative CC1 was used in polymerisation as received, in oil slurry form.
Discussion
[0609] As can be seen from the Table 1, from kinetic curves in
[0610] Comparison of IE1-1 to IE3-1 indicates an importance of metallocene backbone bridge substitution with alkenyl moieties (MC1 complex in IC1-1), to provide some increase of catalyst performance compared to mere short alkyl substitution.
[0611] Comparison of IE2-1 to IE3-1 reveals a surprising effect of slight boost to the gas phase activity by introducing a phenyl substitution into peripheral trimethylsilyl moieties (MC2 complex in IC2-1).
[0612] Comparison of IE1-1 to CE3-1 demonstrates the importance of selective utilisation of pure stereoisomeric forms (in most cases rac-forms) for best performance (MC1 complex in IC1-1 versus MC5 complex in CC3-1).
[0613] Comparison of IE1-1, IE2-1 to CE4-1 (negative effect of tert-butyl substitution of MC6 complex on performance of its catalyst CC4-1) underlines the importance of careful selection of metallocene structure, e.g. the substitution pattern within the same metallocene type (here, bridged furyl-substituted bis-Cp complexes) when high performance is concerned.
[0614] In slurry phase, in terms of catalyst activity, both IC1-1 and IC3-1 had a comparable but somewhat lower activity compared to CC1 (
[0615] The target gas phase split of 58% was achieved in all but two examples (CE2-1 and CE4), where low catalyst activity in slurry required a longer slurry stage time to achieve the required ethylene consumption, which in turn limited the duration of gas phase stage (
[0616] The manifestation of high gas phase performance in form of Gas Phase to Slurry Phase Activity Ratio parameter (from here on GP/SP activity ratio) was clearly achieved for IC1-1 to IC3-1 where the ratio was found to be higher and, in case of IC2-1, significantly higher in comparison to CC1 and especially CC2-1-CC4-1 (
[0617] IC2-1 having a lower performance in slurry phase than IC1-1 and IC3-1 improves its performance in gas phase even slightly beyond the activity level of IC1-1 and IC3-1.
[0618] High activity of IC1-1 in both slurry and in gas phase conditions, can be attributed to the presence of alkenyl chain in the backbone of metallocene structure. The advantage is reduced for its more open meso-form, as demonstrated by CC3-1 which is based on MC5 that has otherwise the same structure as MC1 in IC1-1.
[0619] Poor performance of CC2-1 in comparative example CE2-1 underlines the overall strong advantage of furyl-substituted bridged bis-Cp complexes per se, compared to the classic unbridged bis-Cp complexes when activated and heterogenised in the same way.
[0620] Performance of CC4-1 in example CE4-1 is reduced even though the furyl moiety of its metallocene MC6 is exactly the same as in MC1 or MC3 complexes of IC1-1 and IC3-1. This reveals that introducing one bulky substituent in the Cp-ring in position 4 instead of two small substituents in positions 4 and 5 sterically hinders the approach to metal centre, rendering the complex less useful in polymerisation.
[0621] Lower MFR.sub.2 level in IE1-1-IE3-1 in
[0622] The combination of higher comonomer sensitivity and higher activity (especially in gas phase) brings a special value to the inventive examples for a multi-stage process (
Experiment 2: Two-Step Catalyst Preparation and Polymerisation Examples
[0623] Metallocene complexes MC1-MC7 in this experiment were employed using a significantly different catalyst preparation procedure comprising the two stepspreparation of the aluminoxane-impregnated activated silica support (from here and onSiO.sub.2/MAO) and a subsequent metallocene impregnation as a separate step. As a result, inventive catalysts IC1-2-IC3-2, as well as comparative catalysts CC2-2-CC5-2 were prepared as described in the below two-step method.
General Two-Step Catalyst Preparation Method
[0624] Step A: Activated carrier preparation (SiO.sub.2/MAO)
[0625] 20 g of pre-treated silica and 100 mL of dry Toluene are placed under nitrogen atmosphere into a multi-necked glass reactor equipped with a mechanical stirrer. The gentle mixing is started and the slurry is cooled 10-0 C. Methylaluminoxane solution (233 mmol Al as 30 wt % MAO solution in Toluene) is then slowly added within 30 minutes, while keeping the reaction mixture temperature below 25 C. The slurry is then allowed to stir at room temperature for further 30 minutes. After that, the stirred reaction mixture is heated up to 90 C. within 20 minutes and kept stirred at this temperature for further 2 hours. The slurry is then settled at 90 C. for 15 minutes and the hot supernatant is siphoned off. 100 mL of dry Toluene is added and the SiO.sub.2/MAO carrier is washed under stirring for 30 minutes at 90 C. The carrier is settled and supernatant is siphoned off. A second carrier wash is performed in the same way as above, with a difference that the wash temperature is between 50-70 C. The carrier is settled and supernatant is siphoned off. An extra wash with Heptane at room temperature may be employed to facilitate drying. Supernatant is siphoned off and the activated SiO.sub.2/MAO carrier is dried first in the stream of Nitrogen at 60 C. until no free liquid is observed, followed by thorough drying in vacuo for at least 2 hours at 60 C.
Step B: Catalyst Preparation
[0626] 52.5 mol of metallocene is dissolved in 2.0 mL of dry Toluene by stirring for 1 hour at 20-60 C. in a glass vial under Nitrogen atmosphere. The obtained solution is then added drop-wise within 5 minutes to 2 g of the activated carrier (SiO.sub.2/MAO prepared in step A) in a glass reactor under gentle mechanical stirring at 10-30 C. The crude catalyst is then gently mixed for 1 hour further and left to stand for further 17 hours. The catalyst is then dried in vacuo for 30-60 minutes at 60 C.
TABLE-US-00003 TABLE 2 Bimodal multi-stage copolymerisation with inventive and comparative catalyst examples obtained using one-step catalyst preparation method. Polymerisation example IE1-2 IE2-2 IE3-2 CE1-2 CE2-2 CE3-2 CE4-2 CE5-2 Catalyst IC1-2 IC2-2 IC3-2 CC1 CC2-2 CC3-2 CC4-2 CC5-2 Metallocene in catalyst MC1 MC2 MC3 MC4 MC4 MC5 MC6 MC7 Loading Zr/SiO.sub.2, umol/g 38.33 38.33 38.33 38.33 38.33 38.33 38.33 Loading Al/SiO.sub.2, mmol/g 8.73 8.73 8.73 8.73 8.73 8.73 8.73 Loading Al.sub.SiO2/MAO/Zr ratio 200 200 200 200 200 200 200 Zr content, wt % 0.177 0.185 0.145 0.144 0.172 0.16 0.157 Al content, wt % 13.6 13.9 13.3 13.6 13.8 13.9 13.9 Al/Zr ratio, mol/mol 260 254 310 319 271 294 299 Volatiles content, wt % <0.2 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2 Catalyst amount used (dry 102.5 102.6 101 94 104 102.5 102.7 103.4 basis), mg SP time, min 92 190 183 83 169 196 118 201 GP time, min 42 48 50 73 101* 175 236 SP Activity, kgPE/(gcat .Math. h) 1.3 0.6 0.7 1.6 0.7 0.6 0.3 0.03 GP Activity, kgPE/(gcat .Math. h) 4.2 3.6 3.5 2.6 0.6 1.0 0.2 GP/SP Activity Ratio 3.2 5.6 5.3 1.6 0.9 1.6 0.7 Polymer yield, g 500 491 465 502 296 468 100 2 GP split, wt % 58 58 58 59 33 58 54 MFR.sub.2, g/10 min 1.2 1.2 1.4 2.2 4.6 1.9 179.4 Density, kg/m.sup.3 922.2 921.8 921.3 928.7 933.4 931.2 936.8 1-Butene content, wt % 1.2 1.1 1.1 0.4 1 0.5 0.5 1-Hexene content, wt % 3.9 4.2 4.1 4.1 2.1 3.5 5.6 1-Butene in SP material 2.8 2.6 2.6 1.1 1.4 1.2 1.2 (calc.), wt % 1-Hexene in GP material 6.8 7.3 7.2 6.9 6.3 6.1 10.2 (calc.), wt %
[0627] All inventive catalysts IC1-2-IC3-2 and comparative catalysts CC1, CC2-2-CC5-2 were used in copolymerisation in a multi-stage configuration comprising a prepolymerisation, slurry phase polymerisation and gas phase polymerisation. Polymerisation conditions are described above as the General bench-scale multi-stage Ethylene copolymerisation method and the corresponding copolymerisation inventive examples IE1-2-IE3-2 and comparative examples CE1-2-CE5-2 are disclosed in Table 2. Comparative CC1 was used in polymerisation as received, in oil slurry form.
Discussion
[0628] In spite of the significant difference of the two-step catalyst preparation method and of the employed metallocene and alumoxane loadings described herein in comparison to the Experiment 1, surprisingly and largely similar results and observations were obtained, indicating that both methods are viable alternatives for catalyst preparation.
[0629] As can be seen from the Table 2 and from the performance plots for corresponding polymerisation examples in
[0630] Comparison of IE1-2 to IE3-2 indicates a significance of metallocene backbone bridge substitution with alkenyl moieties, to provide an improved catalyst activity, especially in slurry phase, compared to mere short alkyl substitution.
[0631] Comparison pair-wise of IE1-2 and CE4-2 to CE3-2 and CE5-2 (the latter two are based on respective meso-forms MC5 and MC7) demonstrates the importance of selective utilization of pure stereoisomer forms (in most cases rac-forms) for best performance. Comparison of IE1-2, IE2-2 to CE4-2 (negative effect of tert-butyl substitution in MC6 on performance of CC4-2) underlines the importance of selection of metallocene structure, e.g. the substitution pattern within the same metallocene type (here, bridged furyl-substituted bis-Cp complexes) when high performance is concerned. Performance of CC4-2 is low even though the furyl moiety of the metallocene is exactly the same as in MC1 of IC1-2 and MC3 of IE3-2. It reveals that introducing one bulky substituent in the Cp-ring in position 4 instead of two small substituents in positions 4 and 5 sterically hinders the approach to metal centre, rendering the complex less useful in polymerisation. Its meso-form (MC7) based catalyst CC5-2 possesses even lower, almost negligible performance.
[0632] In slurry phase, in terms of catalyst activity, only IC1-2 manages to more to match the CC1 activity, however in gas phase the performance is different: IC1-2-IC3-2 are superior by catalyst activity compared to catalyst examples CC1 and CC2-2-CC4-2.
[0633] Gas phase split of 58% is achieved with all but CC2-2, CC4-2 and CC5-2 catalysts (
[0634] The key of the invention is the manifestation of high gas phase performance in form of Gas Phase to Slurry Phase Activity Ratio parameter. For polymerisation examples IE1-2-IE3-2 the Ratio is found to be significantly to overwhelmingly higher in comparison to CE1-2-CE4-2 (
[0635] Catalyst IC1-2, owing to its very high activity in both slurry and gas phase, understandably demonstrates (IE1-2) somewhat lower calculated GP/SP Activity Ratio, compared to IC2-2 and IC3-2. The excellent activity of IC1-2 in both slurry and in gas phase conditions is especially prominent, apparently owing to the presence of long alkenyl chain in the backbone of metallocene structure (the alkenyl chain interaction, reversible coordination to active metal centre). Interestingly, such effect becomes lost on more open meso-form, as demonstrated by CC3-2 whose metallocene MC5 has otherwise the same structure as MC1 in IC1-2.
[0636] IC2-2 and IC3-2, having moderate slurry phase performance than IC1-2, improve in gas phase significantly.
[0637] When the same catalyst preparation platform is used for MC4 in CC2-2 (as opposed to a significantly different ActivCat platform in CC1), a fair performance comparison can be drawn between the furyl-based metallocenes (MC1-MC3) in the inventive catalysts and Bis(1-methyl-3-n-butylcyclopentadienyl)zirconium dichloride metallocene MC4. Poor performance of CC2-2 underlines the overall strong advantage of furyl-substituted bridged bis-Cp complexes per se, compared to classic unbridged bis-Cp complexes when activated and heterogenised in the same way.
[0638] Lower MFR.sub.2 level in polymerisation examples IE1-2-IE3-2 clearly indicates a higher molecular weight capability of the corresponding metallocenes MC1-MC3 (
[0639] The combination of higher comonomer sensitivity and higher activity (especially in gas phase) brings a special value to the inventive examples for a multi-stage process (
[0640] It is noteworthy, as mentioned above, that the performance for the inventive and comparative metallocenes, heterogenised using the one-step (Experiment 1) and two-step catalyst preparation method (Experiment 2) are to a large extent similar.