Indian Patents. 253119:SINGLE SITE CATALYST SYSTEMS HAVING A SCORPION-LIKE STRUCTURE

Title of Invention	SINGLE SITE CATALYST SYSTEMS HAVING A SCORPION-LIKE STRUCTURE
Abstract	The inventions discloses a catalyst component of formula IV wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, R10,Z, MX'n, m and n are as defined in the specification. The invention is also for a method for preparing said catalyst component, a catalyst system comprising said catalyst component and a method of oligomerising, homo- or co-polymerising ethylene and alpha-olefins with said catalyst system.

Full Text	The present invention related to the field of single site catalyst systems having scorpion-like three dimensional structure that are suitable for oligomerising or polymerising ethylene and alpha-olefins. There exists a multitude of catalyst systems available for polymerising or oligomerising ethylene and alpha-olefins, but there is a growing need for finding new systems capable to tailor polymers with very specific properties. More and more post- metaliocene catalyst components based on early or late transition metals from Groups 3 to 10 of the Periodic Table have recently been investigated such as for example those disclosed in Gibson and al. review (Gibson, V.C.; Spitzmesser, S.K., Chem. Rev. 2003, 103, p. 283). But there is still a need to improve either the specificities or the performances of these systems. It is an aim of the present invention to provide a new single site catalyst components based on beta-diimine ligands with a chelating pendant arm. It is also an aim of the present invention to provide single site catalyst components having a scorpion-like spatial organisation. It is another aim of the present invention to provide active catalyst systems based on these catalyst components. It is a further aim of the present invention to provide a process for polymerising or for oligomerising ethylene and alpha-olefins with these new catalyst systems. It is also an aim of the present invention to provide a polyethylene by polymerising ethylene with these new catalyst systems. Accordingly, the present invention discloses a ligand of formula I wherein R1, R2, R3, R4, R5. R6, R7, R8, R9 and R10 are each independently selected from hydrogen, unsubstituted or substituted hydrocarbyl, or inert functional group. Two or more of those the groups can themselves be linked together to form further ring or rings. R1 and R3, R2 and R4, and R9 and R10, cannot be simultaneously oxazoline wherein Z is selected from groups 15 or 16 of the Periodic Table and m is the valence pf Z minus one. By inert functional group, is meant a group, other than hydrocarbyl or substituted hydrocarbyl, that is inert under the complexation conditions to which the compound containing said group is subjected. They can be selected for example from halo, ester, ether, amino, imino, nitro, cyano, carboxyl, phosphate, phosphonite, phosphine, phosphinite, thioether and amide. Preferably, they are selected from halo, such as chloro, bromo, fiuoro and iodo, or ether of formula - OR* wherin R* is unsubstituted or substituted hydrocarbyl. After metallation of the ligand, an inert functional group must not coordinate to the metal more strongly than the groups organised to coordinate to the metal and thereby displace the desired coordinating group. It results from the reaction between a beta-diimine II and a compound of formula III wherein X is a leaving group, preferably halogen for example Br. Preferably, R1 and R2 are the same or different and are unsubstituted or substituted alkyl groups, unsubstituted or substituted aryl groups, or unsubstituted or substituted cycloalkyl groups, more preferably, they are unsubstituted or substituted phenyl groups and if they are substituted, the substituents may be joined to form a closed structure. If the phenyls are substituted, the substituents preferably occupy 2 and 6 positions. Preferably, R3 and R4 are the same or different, hydrogen, unsubstituted or substituted alkyl groups, unsubstituted or substituted aryl groups, or unsubstituted or substituted cycloalkyl groups, more preferably, they are unsubstituted or substituted alkyl groups. Optionally R3 and R4 may also be linked together to form a cyclohexyl ring. In another embodiment according to the present invention, R1 with R3 or R2 with R4 are linked together to form a ring. Preferably, R5 is hydrogen, unsubstituted or substituted alkyl groups, unsubstituted or substituted aryl groups, more preferably hydrogen or methyl. Preferably, Z is selected from N, P, O or S. Preferably, R6, R7, R8, R9 and R10 are the same or different, hydrogen, unsubstituted or substituted alkyl groups, unsubstituted or substituted aryl groups, or unsubstituted or substituted cycloalkyl groups. R8, R9 and R10 can be linked together to form a ring, for example a pyridine, a quinoline, an isoquinoline, a pyrrolyl, a furyl or a thiophenyl group. Examples of formula III include 2-(bromomethyl)-5-nitrofuran, 2-(bromomethyl)-1,3- dioxalane, 2-(bromomethyl)tetrahydro-2H-pyran, 2-(bromomethyl)-5- trifluoromethyl)furan, 3(-bramomethyl)pyridazine, 2-bromomethylpyridine, 1 -bromo- 2-ethoxyethane, 2-bromoethylacetate, 1-bromo-2-(2-methoxyethoxy)ethane, [(2- bromoethoxy)methyl]benzene and 3-{bromomethyl)-2,4,10-trioxaadamantane, 2- bromo-N,N-dimethylaniline. The invention also discloses a catalyst component of formula IV: resulting from the complexation of ligand I with the metallic salt MX'n in a solvent, wherein M is a metal Group 3 to 10 of the periodic Table, X' is the same or different and can be a halogen, alcoholate, or substituted or unsubstituted hydrocarbyl and n is the valence of M. Preferably, M is Ti, Zr, Hf, V, Cr, Mn, Fe, Co, Ni, Pd or rare earths. More preferably, it is Cr or Fe. The metal is complexed with the two nitrogen atoms of the starting beta-diimine and during the complexation reaction, the complex folds around the carbon atom joining atom Z to the metal to form a three dimensional scorpion-like structure. The solvent may be selected from dichloromethane or tetrahydrofuran and the complexation reaction is carried out at room temperature. The present invention also discloses an active catalyst system comprising the single site catalyst component of formula IV and an activating agent having an ionising action. Suitable activating agents are well known in the art. The activating agent can be an aluminium alkyl represented by formula AIR+nX3-n wherein R+ is an alkyl having from 1 to 20 carbon atoms and X is a halogen. The preferred alkylating agents are triisobutyl aluminium (TIBAL) or triethyl aluminium (TEAL). Alternatively, it can be aluminoxane and comprise oiigomeric linear and/or cyclic alkyl aluminoxanes represented by formula for oiigomeric, linear aluminoxanes and by formula for oiigomeric, cyclic aluminoxane, wherein n is 1-40, preferably 1-20, m is 3-40, preferably 3-20 and R* is a C1-C8 alkyl group and preferably methyl or isobutyl. Preferably, the activating agent is methylaluminoxane (MAO) or tetra- isobutyldialuminoxane (IBAO), more preferably, it is IBAO. The amount of activating agent is selected to give an Al/M ratio of from 100 to 3000, preferably of from 500 to 2000. The amount of activating agent depends upon its nature, the preferred Al/M ratio being of about 2000. Suitable boron-containing activating agents may comprise a triphenylcarbenium boronate such as tetrakis-pentafluorophenyl-borato-triphenylcarbenium as described in EP-A-0427696, or those of the general formula [L'-H] + [B Ar1 Ar2 X3 X4]- as described in EP-A-0277004 (page 6, line 30 to page 7, line 7). The amount of boron-containing activating agent is selected to give a B/M ratio of from 0.5 to 5, preferably of about 1, In another embodiment, according to the present invention, the single site catalyst component of formula IV may be deposited on a conventional support. Preferably, the conventional support is silica impregnated with MAO. It may also be an activating support such as a fluorided alumina silica. The present invention further discloses a method for preparing an active catalyst system that comprises the steps of: a) providing a beta-diimine ligand precursor of formula II; - b) reacting the beta-diimine ligand precursor of formula II with compound III; c) retrieving the scorpion-like ligand I d) complexing the ligand obtained in step c) with a metallic salt MX'n; e) retrieving a catalyst component of formula IV; f) activating with an activating agent having an ionising action; g.) optionally adding a cocatalyst h) retrieving an active oligomerisation or polymerisation catalyst system. Alternatively, in step f) catalyst component IV is deposited on a support impregnated with an activating agent or on an activating support containing fluor. The cocatalyst may be selected from triethylaluminium, triisobutylaluminum, tris-n- octylaluminium, tetraisobutyldialuminoxane or diethyl zinc. The active catalyst system is used in the oligomerisation and in the polymerisation of ethylene and alpha-olefins. The present invention discloses a method for the oligomerisation or the homo- or co- polymerisation of ethylene and alpha-olefins that comprises the steps of: a) injecting the active catalyst system into the reactor; b) injecting the monomer and optional comonomer either before or after or simultaneously with step a); c) maintaining under polymerisation conditions; d) retrieving the oligomers and/or polymer. The pressure in the reactor can vary from 0.5 to 50 bars, preferably from 5 to 25 bars. The polymerisation temperature can range from 10 to 100°C, preferably from 50 to 85°C. The preferred monomer and optional comonomer can be selected from ethylene, propylene or 1-hexene. Alternatively, the optional comonomer can be a polar functionalised alpha-olefin. With a catalyst activated by MAO, the polymer formed is caracterized by a melting point comprised between 100 and 135 °C, preferably between 125 and 131 °C as measured by Differential Scanning Calorimetry (DSC) method. It has a multimodal molecular weight distribution with a molecular weight Mw of from 50000 to 500000, preferably of from 75000 to 250000, and a molecular weight distribution of 15 to 50 depending on the solvent. The molecular weight distribution is measured by the polydispersity index D defined as the ratio Mw/Mn of the weight average molecular weight Mw over the number average molecular weight Mn. Molecular weights are measured by Gel Permeation Chromatography (GPC). With a catalyst activated by IBAO, the polymer formed is characterised by a melting point of about 135 °C as measured by Differential Scanning Calorimetry (DSC) method. It has a broad monomodal molecular weight distribution with a molecular weight Mw of 765000, and a molecular weight distribution of 25. The molecular weight distribution is measured by the polydispersity index D defined as the ratio Mw/Mn of the weight average molecular weight Mw over the number average molecular weight Mn. Molecular weights are measured by Gel Permeation Chromatography (GPC). 13C NMR analysis showed the presence of linear (12 per 10000 carbon atoms) and isobutyle (10 per 10000 C atoms) saturated end chains,. No short chain branching were detected. With a supported catalyst, the polymer formed has a monomodal molecular weight distribution with a molecular weight Mw of from 150000 to 350000, preferably of from 180000 to 280000, and a molecular weight distribution of 5 to 20. it has a melting point comprised between 125 and 135 °C. It has no short chain branching detectable by 13C NMR analysis but it has long chain branching. The presence of the long chain branching is indicated by RDA analysis. Throughout this description, LCB means chains long enough for entanglements to occur. In order to quantify LCB concentration with rheology, we have adapted Shroff and Mavridis definition of LCBI (Long Chain Branching Index) to our high molecular weight PE samples. (R. N. Shroff and H. Mavridis, Macromolecules, 32,8454,1999.) As explained by those authors, LCBI quantifies the Theological effect of LCB (enhancement of shear viscosity at low shear rates) for narrow and broad molecular weight distribution (MWD) samples with sparse amount of LCB, that is LCB concentration typically too low to be detected by 13C NMR (for homopolymers PE) or by solution techniques such as size exclusion chromatography (SEC) coupled with on-line viscosity or light scattering detectors. DRI (Dow Rheology Index) which is another LCB indicator described in lai et al. (S. Lai, T. A. Plumley, T. I. Butler, G. W. Knight, C. I. Kao, SPE AntecTechn. Papers, 40,1814,1994) is not suitable to quantify LCB in polyethylene resins with polydispersity index larger than 4. DRI is thus not suitable to gauge LCB in our PE resins with broad MWD. According to those authors, LCBI is defined as the ratio of intrinsic viscosities of PE resins estimated by rheoiogy to that determined via solution techniques. wherein [nlrheo and [n]sol are the intrinsic viscosities obtained respectively from rheoiogy or via solution. Thus, LCBI is zero for linear samples and is above zero for polyethylene containing long chain branching. A high level of LCB is encountered with LCBI above 0.8. Instead of determining intrinsic viscosity from the relative viscosity at 0.2 dg/min as explained in their publication, we calculate intrinsic viscosity value via solution (expressed in dl/g) in terms of weight average molecular weight Mw (expressed in Da) obtained by size exclusion chromatography (SEC) with equation Zero shear viscosity (η0) (expressed in Pa.s) is also related to Mw (expressed in Da) by equation Zero shear viscosity is estimated by fitting with Carreau-Yasuda flow curve at 190°C, obtained by oscillatory shear rheoiogy on ARES equipment in the linear viscoelasticiiy domain. Circular frequency (W in rad/s) varies from 0.05-0.1 rad/s to 250-500 rad/s and the shear strain is typically 10 %. The intrinsic viscosity inferred from rheoiogy can thus be expressed as wherein x, b and n are fitting parameters called relaxation time, breadth parameter and power-law parameter, respectively. The LCBl is thus rewritten as In order to increase the accuracy in estimating zero shear viscosity, a frequency sweep experiment having a typical range of 0.1-250 rad/s, is combined with a creep experiment, in order to extend the frequency range to values down to 10-4 s-1 or lower, and taking the usual assumption of equivalence of angular frequency (rad/s) and shear rate. Frequency sweep experiments are performed using small parallel plates having a diameter of 8 mm that allow flow curve determination with as little as 0.1 g PE. Also, most tests are conducted at a temperature of 2309C for polymers that do not exhibit homogeneous flow below that temperature. Thus, LCBl is derived at a temperature of 230°C using extrapolated shear viscosity at 0.001 s"1 as follows. The subscript 230 recalls that LCBl is determined from frequency sweep experiments conducted at 230°C. The relationship between viscosity and Mw is established as usual with a series of linear polyethylene. The viscosity/Mw relationship was established with a series of 15 linear PE having a polydispersity index betxeen 2 and 18. ZN or metallocene-produced polyethylene known to be linear have a LCBl of 0 +/ 0.1. Thus, PE with LCB are detected above LCBl of 0.1-0.2 List of accompanying figures. Figure 1 represents the molecular weight distribution of the polyethylene obtained in examples. Figure 2 represents the molecular weight distribution of the polyethylenes obtained in examples 9 and 11. Examples- Preparation of catalyst component Synthesis of the liaand 1. Step l. The beta-diimine was synthesised according to the published procedure of Feldman and al. (Organometallics 1997,16, p. 1514). Step 2. 760 mg (3 mmol) of 2-bromomethylpyridine.HBr and 436 mg (3.15 mmbl) of potassium carbonate weredegassed under vacuum for 1 hour. 10 mL of dry acetone were added and the mixture was stirred under argon for 6 hours at room temperature (about 25 °C). The solvent was removed and the 2-bromomethylpyridine was extracted with 3 x 10 mL of diethyl ether under inert atmosphere. The solvent was removed to afford a pink oil with quantitative yield. Step 3. 1.26 g (3 mmol) of beta-diimine were dissolved in 15 mL of dry THF under argon. The solution was cooled to a temperature of -20°C and 2 mL (3.15 mmol) of n-BuLi (1.6 M in hexane) were added dropwise. The colourless solution turned immediately to bright yellow and was stirred at room temperature for 30 minutes. The solution was cooled to a temperature of -20°C and a solution of 2-bromomethylpyridine in 10 mL of dry THF was added by canula. The solution was allowed to warm to room temperature and was stirred overnight, before being heated at 80°C for 6 hours under reflux. After that time, the solvent was evaporated to dryness. The residue was taken with 10 mL of dichloromethane and filtered over neutral alumina. The solution was evaporated to afford a yellow oil purified by column chromatography (SiO2, pentane:diethyl ether 95:5 to 80:20). 910 mg of the expected product were obtained as pale yellow oil containing isomers 1a and 1b, with a yield of 60 %. The isomers were characterised as follows: C35H47N3 M=509.77 g.mol-1 1H NMR (500 MHz, CDCI3) results: Isomer 1a: 8= 1.10 (m, 12H, CH3 /Pr), 1.21 (dd, 12H, J=6.8 Hz, CH3 /Pr), 1.92 (s, 6H, CH3CN), 2.53 (sept, 2H, J=6.8 Hz, CH /Pr), 2.60 (sept, 2H, J=6.8 Hz, CH /Pr), 3.65 (d, 2H, J=7.5 Hz, CH2), 4.70 (t, 1H, J=7.5 Hz, CH), 7.11 (m, 2H, CH para Ph), 7.17 (br s, 4H, CH meta Ph), 7.22 (m, 1H, H5 pyr), 7.38 (d, 1H, J=7.5 Hz, H3 pyr), 7.66 (td, 1H, J=7.5 Hz, J=1.8 Hz, H4 pyr), 8.66 (d, 1H, J=5 Hz, H6 pyr). Isomer 1b: 8=1.07 (m, 12H, CH3/Pr), 1.13 (d, 12H, J=6.9 Hz, CH3/Pr), 1.78 (s, 6H, CH3CN), 3.20 (sept, 4H, J=6.9 Hz, CH /Pr), 4.06 (s, 2H, CH2), 7.09 (m, 2H, CH para Ph), 7.13 (m, 4H, CH meta Ph), 7.18 (m, 1H, H5 pyr), 7.33 (d, 1H, J=7.8 Hz, H3 pyr), 7.68 (m, 1H, H4 pyr), 8.61 (d, 1H, J=5 Hz, H6 pyr). Preparation of Fe(ll) complex 2. 210 mg (0.4 mmol) of beta-diimine-methylpyridine (1a and 1b) and 84 mg (0.4 mmol) of iron (II) chloride tetrahydrate were degassed under vacuum for 1 hour. 10 mL of dry tetrahydrofuran (THF) were added and the mixture was stirred under argon overnight at room temperature. The solid was filtered off and the filtrate was concentrated to dryness to afford 228 mg of Fe(ll) complex 2 as a brown-yellow powder with a yield of 87%. It had formula C35H47Cl2FeN3 and a molar weight of 636.51 g.mol -1. Mass spectroscopy: ESI (Electron Spray lonisation), solvent = CH3CN: m/z = 601.28 [M-CI]+. The calculations for C35H47FeClN3 gave a value of 600.2808. Preparation of Cr(III) complex 3. 210 mg (0.4 mmol) of beta-diimine-methylpyridine and 162 mg (0.4mmol) of chromium (III) chloride tetrahydrofuran were degassed under vacuum for 1 hour. 10 mL of dry tetrahydrofuran were added and the mixture was stirred under argon overnight at room temperature. The solid was filtered off and the filtrate concentrated to dryness to afford 274 mg of Cr(lll) complex 3 as a pink powder with a yield of 95 %. It had formula C35H47Cl3CrN3 and a molar weight of 668.13 g.mol-1. Mass spectroscopy: ESI (Electron Spray lonisation), solvent = CH3CN: m/z = 631.25 [M-Cfj+. The calculations for C35H47CrCl2N3 gave a value of 631.2552. Preparation of Co(II) complex 4. 51 mg (0.1 mmol) of beta-diimine-methylpyridine (1a and 1b) and 13 mg (0.1 mmol) of cobalt (II) chloride were degassed under vacuum for 1 hour. 5 ml_ of dry dichloromethane were added and the mixture was stirred under argon overnight at room temperature. The solid was filtered off and the filtrate was concentrated under vacuum to approximately 2 ml_. 20 mL of dry pentane were added to precipitate the complex. The solvent was removed by filtration under argon and the resulting powder washed twice with 5 mL of dry pentane. The solid was dried under vacuum to afford 44 mg of Co(ll) complex 4 as a green powder with a yield of 69%. It had formula C35H47CI2C0N3 and a molar weight of 639.61 g.mol-1. Preparation of Fe(III) complex 5. 51 mg (0.1 mmol) of beta-diimine-methylpyridine (1a and 1b) and 13 mg (0.1 mmol) of iron (III) chloride were degassed under vacuum for 1 hour. 5 mL of dry tetrahydrofuran (THF) were added and the mixture was stirred under argon overnight at room temperature. The solid was filtered off and the filtrate was concentrated to dryness to afford 45 mg of Fe complex 5 as a brown-yellow powder with a yield of 67%. It had formula C35H47Cl3FeN3 and a molar weight of 671.97 g.mol-1. Synthesis of ligands 6 Using the procedure described for ligand 1 (step 1, 2 and 3), ligand 6 was obtained with a yield of 61%. 1H NMR (500 MHz, CDCI3)■: δ = 1.26 (s, 18H, CH3 ffiu), 2.00 (s, 6H, CH3CN), 3.63 (d, 2H, J=7.5 Hz, CH2), 4.44 (t, 1H, J=7.5 Hz, CH), 6.25 (d, 2H, J=7.5 Hz), 7.05 (m, 6H), 7.34 (t, 2H, J=7.5 Hz), 7.62 (t, 1H, J=7.5 Hz), 8.59 (d, 1H, J=5 H). Synthesis of ligands 7 Using the procedure described for iigand 1 (step 1, 2 and 3), iigand 7 was obtained with a yield of 41%. 1H NMR (500 MHz, CDCI3) : δ= 1.80 (s, 6H, CH3), δ= 1.84 (s, 12H, CH3), 2.25 (s, 6H, CH3), 3.60 (d, 2H, J=7.5 Hz, CH2), 4.53 (t, 1H, J=7.5 Hz, CH), 6.90 (s, 4H), 7.1- 7.25 (m, 1H), 7.30-7.80 (m, 3H), 8.58 (m, 1H). Preparation of complexes 8 Using the procedure described for complex 3, complex 8 was obtained with a yield of 68%. Preparation of complexes 9 Using the procedure described for complex 3, complex 9 was obtained with a yield of 63%. Preparation of complex 10. 150 mg (0,3 mmol) of ligand 1 and 36 mg (0.3mmol) of chromium (II) chloride were degassed under vacuum for 1 hour. 10 mL of dry tetrahydrofuran were added and the mixture was stirred under argon overnight at room temperature. The reaction mixture was concentrated to 2ml and 10 mL of pentane was added. The solid was filtered off and washed twice with 5mL of pentane. The solid was dried to afford 186 mg of Cr(ll) complex 10 as a green powder with a yield of 58 %. Preparation of the complexes 11 Using the procedure described for complex 10, complex 11 was obtained with a yield of 37%, Preparation of the complexes 12 Using the procedure describe for complex 10, complex 12 was obtained with a yield of 46%. High pressure polymerisation of ethylene. Ethylene polymerisation reactions were performed in a 20 mL stainless steel autoclave containing a glass insert, fitted with mechanical stirring, external thermocouple and pressure gauge and controlled by computer. In a typical reaction run, 4 mL of dry solvent (toluene or n-heptane) were introduced into the reactor, the temperature was raised to 50 oC and the ethylene pressure was raised to 15 bar and continuously fed. In a argon-filled glove box, about 5 umol of the appropriate catalyst were weighted, activated with an amount of methylaluminoxane (MAO 30 % wt in toluene) or tetraisobutyldialuminoxane (IBAO 10 wt % in toluene) activator in an amount appropriate to obtain a ratio [Al]:[M3 of 2000 and diluted with toluene to a final volume of 2 mL. 200 µL of the solution of the activated catalyst were placed inside the reactor. The injection loop was rinsed with 800 uL of solvent. After 1 hour or a consumption of 12 mmol of ethylene, the reaction was quenched with isopropanol and an aliquot analysed by gas chromatography. The gas chromatographic analysis of the reaction products were performed on a Trace GC apparatus with a Petrocol capillary column (methyl silicone, 100 m long, i.d. 0.25 mm and film thickness of 0.5 urn) working at a temperature of 35°C for 15 min and then heated to a temperature of 250 °C at a heating rate of 5sC/min. The remaining reaction mixture was quenched with MeOH / HCI and the polymer was filtered, washed with methanol and dried at a temperature of 50°C, under vacuum, for a period of time of 24 hours. The reaction conditions for each example are displayed in Table I and the results are displayed in Table II and in Table III. Oligomerisation of 1-haxene. In a argon-filled glove box, about 7.5 µmol of the appropriate catalyst were weighted, activated with an amount of methylaluminoxsne (MAO) activator, 30 % wt in toluene, suitable to give a [AI]:[M] ratio of 2000 and diluted with toluene to a final volume of 4.5 mL 3 mL of the solution of the activated catalyst were placed in a Schlenk tube containing 5 mL of 1-hexene. The solution was stirred at a temperature of 30°C for 1 hour. The mixture was quenched with slightly acidified methanol. The layers were separated. The toluene layer was concentrated to dryness to afford oligomers. The gas chromatographic analysis of the reaction products was done on a Trace GC apparatus with a Petrocol capillary column (methyl silicone, 100 m long, i.d. 0.25 mm and film thickness of 0.5 µm) working at a temperature of 100°C for 4 min and then heated to a temperature of 250 °C at a heating rate of 8°C/min. The results are displayed in Table IV. Ethylene polymerisation reactions were carried out in a 130 ml stainless steel autoclave equipped with mechanical stirring and a stainless steel injection cylinder. In a typical reaction run, the reactor was first dried under nitrogen flow at 100PC during 10 min. Then it was cooled down to the reaction temperature (50° or 85°C) and 35 ml of isobutane were introduced into the reactor with a syringe pump, followed by the comonomer if required. The pressure was adjusted to the desired value (14.8 or 23.8 bar) with ethylene. In an argon-filled glove box, 300 mg of the supported catalyst (complex 3 deposited on MAO impregnated silica, at 2 wt % based on the total weight of the supported catalyst), the cocatalyst and 0.6 ml of n-hexane were placed into the injection cylinder. The valve was closed and the cylinder was connected to the reactor under nitrogen flow. The active catalyst mixture was then introduced into the reactor with 40 ml of isobutane. After 30 minutes or 1 hour, the reactor was cooled down to room temperature and slowly depressurised, and the polymer was recovered. The polymerisation results are displayed in Table V. The obtained polymers were characterized by GPC in TCB at 140°C, by DSC, by RDA at 230°C and by 13C NMR in TCB at 135°C. The results are displayed in table VI and figure 2. The 13C NMR analysis for examples 10 and 12, showed the absence of short chain branching (less than 0.1 mol%) and the presence of saturated and vinylic ends. It can thus be seen that the polymers according to the present invention have a very high level of long chain branching, in fact much larger than the polymers prepared with bis-tetrahydroindenyl metallocene catalyst components known to have a high level of high chain branching and who exhibit a LCBI typically of from 0.5 to 1. WE CLAIM: 1. A catalyst component of formula IV wherein R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10 are each independently selected from hydrogen, unsubstituted or substituted hydrocarbyl or inert functional group selected from halo, ester, ether, amino, imino, nitro, cyano, carboxyl, phosphate, phosphonite, phosphine, phosphinite, thioether and amide, and wherein R1 and R2 are unsubstituted or substituted alkyl groups, unsubstituted or substituted aryl groups, unsubstituted or substituted cycloalkyl groups, R3 and R4 are unsubstituted or substituted alkyl groups, unsubstituted or substituted aryl groups, unsubstituted or substituted cycloalkyl groups, R5 is hydrogen or methyl, R6, R7, R8, R9 and R10 are unsubstituted or substituted alkyl groups, unsubstituted or substituted aryl groups, unsubstituted or substituted cycloalkyl groups, and two groups can be linked together to form further ring or rings, with the restriction that R1 and R3, R2 and R4, and R9 and R10, cannot be simultaneously oxazoline, and wherein Z is selected from N, P, O or S and m is the valence of Z minus one, wherein M is a metal selected from Ti, Zr, Hf, V, Cr, Mn, Fe, Co, Ni, Pd or rare earth, wherein X' are the same or different and are halogen or substituted or unsubstituted hydrocarbyl and wherein n is the valence of M and characterised in that the complex folds around the carbon atom preceding Z to allow joining Z to metal M in order to form a three dimensional scorpion-like structure. 2. The catalyst component as claimed in claim 1 wherein R1 and R2 are unsubstituted or substituted phenyl groups. 3. The catalyst component as claimed in claim 1 wherein R3 and R4 are unsubstituted or substituted alkyl groups. 4. The catalyst component as claimed in claim 3 wherein R3 and R4 are linked together to form a cyclohexyl ring. 5. The catalyst component as claimed in any one of the preceding claims wherein R8, R9 and R10 can be linked together to form a ring, for example a pyridine, a quinoline, an isoquinoline, a pyrrolyl, a furyl or a thiophenyl group. 6. The catalyst component as claimed in any one of the preceding claims wherein M is Cr. 7. A method for preparing the catalyst component as claimed in any one of claims 1 to 6 by complexing a ligand of formula I with a metallic salt MX'n in a solvent, wherein all R1, R2, R3, R4, R5, R6, R7, R8.R9 and R10 and M are as defined in the preceding claims, wherein X is halogen or substituted or unsubstituted hydrocarbyl and n is the valence of M. 8. An active catalyst system comprising the catalyst component as claimed in any one of claims 1 to 6 and an activating agent having an ionising action as herein described and optionally a cocatalyst selected from triethylaluminium, triisobutylaluminium, tris-n-octylaluminium, tetraisobutyldialuminoxane or diethyl zinc. 9. An active catalyst system comprising the tridentate catalyst component as claimed in any one of claims 1 to 6, an activating support and optionally a cocatalyst selected from triethylaluminium, triisobutylaluminium, tris-n-octylaluminium, tetraisobutyldialuminoxane or diethyl zinc. 10. A method for oligomerising or homo- or co-polymerising ethylene and alpha- olefins that comprises the steps of: a) injecting the active catalyst system of claim 8 or claim 9 into the reactor; b) injecting the monomer and optional comonomer either before or after or simultaneously with step a); c) maintaining under polymerisation conditions at a temperature from 10 to 100 °C and a pressure fom 0.5 to 50 bars; d) retrieving oligomers or a polymer. 11. The method as claimed in claim 10 wherein the monomer and optional comonomer are selected from ethylene, propylene or 1-hexene. 12. The method as claimed in claim 10 or claim 11 wherein the optional comonomer is a polar functionalised alpha-olefin. ABSTRACT SINGLE SITE CATALYST SYSTEMS HAVING A SCORPION-LIKE STRUCTURE The inventions discloses a catalyst component of formula IV wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, R10,Z, MX'n, m and n are as defined in the specification. The invention is also for a method for preparing said catalyst component, a catalyst system comprising said catalyst component and a method of oligomerising, homo- or co-polymerising ethylene and alpha-olefins with said catalyst system.

Full Text

The present invention related to the field of single site catalyst systems having
scorpion-like three dimensional structure that are suitable for oligomerising or
polymerising ethylene and alpha-olefins.
There exists a multitude of catalyst systems available for polymerising or
oligomerising ethylene and alpha-olefins, but there is a growing need for finding new
systems capable to tailor polymers with very specific properties. More and more post-
metaliocene catalyst components based on early or late transition metals from
Groups 3 to 10 of the Periodic Table have recently been investigated such as for
example those disclosed in Gibson and al. review (Gibson, V.C.; Spitzmesser, S.K.,
Chem. Rev. 2003, 103, p. 283). But there is still a need to improve either the
specificities or the performances of these systems.
It is an aim of the present invention to provide a new single site catalyst components
based on beta-diimine ligands with a chelating pendant arm.
It is also an aim of the present invention to provide single site catalyst components
having a scorpion-like spatial organisation.
It is another aim of the present invention to provide active catalyst systems based on
these catalyst components.
It is a further aim of the present invention to provide a process for polymerising or for
oligomerising ethylene and alpha-olefins with these new catalyst systems.
It is also an aim of the present invention to provide a polyethylene by polymerising
ethylene with these new catalyst systems.
Accordingly, the present invention discloses a ligand of formula I

wherein R1, R2, R3, R4, R5. R6, R7, R8, R9 and R10 are each independently
selected from hydrogen, unsubstituted or substituted hydrocarbyl, or inert functional
group. Two or more of those the groups can themselves be linked together to form
further ring or rings.
R1 and R3, R2 and R4, and R9 and R10, cannot be simultaneously oxazoline
wherein Z is selected from groups 15 or 16 of the Periodic Table and m is the
valence pf Z minus one.
By inert functional group, is meant a group, other than hydrocarbyl or substituted
hydrocarbyl, that is inert under the complexation conditions to which the compound
containing said group is subjected. They can be selected for example from halo,
ester, ether, amino, imino, nitro, cyano, carboxyl, phosphate, phosphonite,
phosphine, phosphinite, thioether and amide. Preferably, they are selected from halo,
such as chloro, bromo, fiuoro and iodo, or ether of formula - OR* wherin R* is
unsubstituted or substituted hydrocarbyl. After metallation of the ligand, an inert
functional group must not coordinate to the metal more strongly than the groups
organised to coordinate to the metal and thereby displace the desired coordinating
group.

It results from the reaction between a beta-diimine II and a compound of formula III
wherein X is a leaving group, preferably halogen for example Br.

Preferably, R1 and R2 are the same or different and are unsubstituted or substituted
alkyl groups, unsubstituted or substituted aryl groups, or unsubstituted or substituted
cycloalkyl groups, more preferably, they are unsubstituted or substituted phenyl
groups and if they are substituted, the substituents may be joined to form a closed
structure. If the phenyls are substituted, the substituents preferably occupy 2 and 6
positions.
Preferably, R3 and R4 are the same or different, hydrogen, unsubstituted or
substituted alkyl groups, unsubstituted or substituted aryl groups, or unsubstituted or
substituted cycloalkyl groups, more preferably, they are unsubstituted or substituted
alkyl groups. Optionally R3 and R4 may also be linked together to form a cyclohexyl
ring.
In another embodiment according to the present invention, R1 with R3 or R2 with R4
are linked together to form a ring.
Preferably, R5 is hydrogen, unsubstituted or substituted alkyl groups, unsubstituted
or substituted aryl groups, more preferably hydrogen or methyl.
Preferably, Z is selected from N, P, O or S.
Preferably, R6, R7, R8, R9 and R10 are the same or different, hydrogen,
unsubstituted or substituted alkyl groups, unsubstituted or substituted aryl groups, or
unsubstituted or substituted cycloalkyl groups. R8, R9 and R10 can be linked

together to form a ring, for example a pyridine, a quinoline, an isoquinoline, a pyrrolyl,
a furyl or a thiophenyl group.
Examples of formula III include 2-(bromomethyl)-5-nitrofuran, 2-(bromomethyl)-1,3-
dioxalane, 2-(bromomethyl)tetrahydro-2H-pyran, 2-(bromomethyl)-5-
trifluoromethyl)furan, 3(-bramomethyl)pyridazine, 2-bromomethylpyridine, 1 -bromo-
2-ethoxyethane, 2-bromoethylacetate, 1-bromo-2-(2-methoxyethoxy)ethane, [(2-
bromoethoxy)methyl]benzene and 3-{bromomethyl)-2,4,10-trioxaadamantane, 2-
bromo-N,N-dimethylaniline.
The invention also discloses a catalyst component of formula IV:

resulting from the complexation of ligand I with the metallic salt MX'n in a solvent,
wherein M is a metal Group 3 to 10 of the periodic Table, X' is the same or different
and can be a halogen, alcoholate, or substituted or unsubstituted hydrocarbyl and n
is the valence of M.
Preferably, M is Ti, Zr, Hf, V, Cr, Mn, Fe, Co, Ni, Pd or rare earths. More preferably, it
is Cr or Fe.
The metal is complexed with the two nitrogen atoms of the starting beta-diimine and
during the complexation reaction, the complex folds around the carbon atom joining
atom Z to the metal to form a three dimensional scorpion-like structure.

The solvent may be selected from dichloromethane or tetrahydrofuran and the
complexation reaction is carried out at room temperature.
The present invention also discloses an active catalyst system comprising the single
site catalyst component of formula IV and an activating agent having an ionising
action.
Suitable activating agents are well known in the art. The activating agent can be an
aluminium alkyl represented by formula AIR+nX3-n wherein R+ is an alkyl having from
1 to 20 carbon atoms and X is a halogen. The preferred alkylating agents are
triisobutyl aluminium (TIBAL) or triethyl aluminium (TEAL).
Alternatively, it can be aluminoxane and comprise oiigomeric linear and/or cyclic alkyl
aluminoxanes represented by formula

for oiigomeric, linear aluminoxanes and by formula

for oiigomeric, cyclic aluminoxane,
wherein n is 1-40, preferably 1-20, m is 3-40, preferably 3-20 and R* is a C1-C8 alkyl
group and preferably methyl or isobutyl.
Preferably, the activating agent is methylaluminoxane (MAO) or tetra-
isobutyldialuminoxane (IBAO), more preferably, it is IBAO.

The amount of activating agent is selected to give an Al/M ratio of from 100 to 3000,
preferably of from 500 to 2000. The amount of activating agent depends upon its
nature, the preferred Al/M ratio being of about 2000.
Suitable boron-containing activating agents may comprise a triphenylcarbenium
boronate such as tetrakis-pentafluorophenyl-borato-triphenylcarbenium as described
in EP-A-0427696, or those of the general formula [L'-H] + [B Ar1 Ar2 X3 X4]- as
described in EP-A-0277004 (page 6, line 30 to page 7, line 7).
The amount of boron-containing activating agent is selected to give a B/M ratio of
from 0.5 to 5, preferably of about 1,
In another embodiment, according to the present invention, the single site catalyst
component of formula IV may be deposited on a conventional support. Preferably,
the conventional support is silica impregnated with MAO. It may also be an activating
support such as a fluorided alumina silica.
The present invention further discloses a method for preparing an active catalyst
system that comprises the steps of:
a) providing a beta-diimine ligand precursor of formula II; -
b) reacting the beta-diimine ligand precursor of formula II with compound III;
c) retrieving the scorpion-like ligand I
d) complexing the ligand obtained in step c) with a metallic salt MX'n;
e) retrieving a catalyst component of formula IV;
f) activating with an activating agent having an ionising action;
g.) optionally adding a cocatalyst
h) retrieving an active oligomerisation or polymerisation catalyst system.
Alternatively, in step f) catalyst component IV is deposited on a support
impregnated with an activating agent or on an activating support containing fluor.
The cocatalyst may be selected from triethylaluminium, triisobutylaluminum, tris-n-
octylaluminium, tetraisobutyldialuminoxane or diethyl zinc.

The active catalyst system is used in the oligomerisation and in the polymerisation of
ethylene and alpha-olefins.
The present invention discloses a method for the oligomerisation or the homo- or co-
polymerisation of ethylene and alpha-olefins that comprises the steps of:
a) injecting the active catalyst system into the reactor;
b) injecting the monomer and optional comonomer either before or after or
simultaneously with step a);
c) maintaining under polymerisation conditions;
d) retrieving the oligomers and/or polymer.
The pressure in the reactor can vary from 0.5 to 50 bars, preferably from 5 to 25
bars.
The polymerisation temperature can range from 10 to 100°C, preferably from 50 to
85°C.
The preferred monomer and optional comonomer can be selected from ethylene,
propylene or 1-hexene. Alternatively, the optional comonomer can be a polar
functionalised alpha-olefin.
With a catalyst activated by MAO, the polymer formed is caracterized by a melting
point comprised between 100 and 135 °C, preferably between 125 and 131 °C as
measured by Differential Scanning Calorimetry (DSC) method. It has a multimodal
molecular weight distribution with a molecular weight Mw of from 50000 to 500000,
preferably of from 75000 to 250000, and a molecular weight distribution of 15 to 50
depending on the solvent. The molecular weight distribution is measured by the
polydispersity index D defined as the ratio Mw/Mn of the weight average molecular
weight Mw over the number average molecular weight Mn. Molecular weights are
measured by Gel Permeation Chromatography (GPC).
With a catalyst activated by IBAO, the polymer formed is characterised by a melting
point of about 135 °C as measured by Differential Scanning Calorimetry (DSC)

method. It has a broad monomodal molecular weight distribution with a molecular
weight Mw of 765000, and a molecular weight distribution of 25. The molecular
weight distribution is measured by the polydispersity index D defined as the ratio
Mw/Mn of the weight average molecular weight Mw over the number average
molecular weight Mn. Molecular weights are measured by Gel Permeation
Chromatography (GPC). 13C NMR analysis showed the presence of linear (12 per
10000 carbon atoms) and isobutyle (10 per 10000 C atoms) saturated end chains,.
No short chain branching were detected.
With a supported catalyst, the polymer formed has a monomodal molecular weight
distribution with a molecular weight Mw of from 150000 to 350000, preferably of from
180000 to 280000, and a molecular weight distribution of 5 to 20. it has a melting
point comprised between 125 and 135 °C. It has no short chain branching detectable
by 13C NMR analysis but it has long chain branching. The presence of the long chain
branching is indicated by RDA analysis.
Throughout this description, LCB means chains long enough for entanglements to
occur.
In order to quantify LCB concentration with rheology, we have adapted Shroff and
Mavridis definition of LCBI (Long Chain Branching Index) to our high molecular
weight PE samples. (R. N. Shroff and H. Mavridis, Macromolecules, 32,8454,1999.)
As explained by those authors, LCBI quantifies the Theological effect of LCB
(enhancement of shear viscosity at low shear rates) for narrow and broad molecular
weight distribution (MWD) samples with sparse amount of LCB, that is LCB
concentration typically too low to be detected by 13C NMR (for homopolymers PE) or
by solution techniques such as size exclusion chromatography (SEC) coupled with
on-line viscosity or light scattering detectors. DRI (Dow Rheology Index) which is
another LCB indicator described in lai et al. (S. Lai, T. A. Plumley, T. I. Butler, G. W.
Knight, C. I. Kao, SPE AntecTechn. Papers, 40,1814,1994) is not suitable to
quantify LCB in polyethylene resins with polydispersity index larger than 4. DRI is
thus not suitable to gauge LCB in our PE resins with broad MWD.

According to those authors, LCBI is defined as the ratio of intrinsic viscosities of PE
resins estimated by rheoiogy to that determined via solution techniques.

wherein [nlrheo and [n]sol are the intrinsic viscosities obtained respectively from
rheoiogy or via solution.
Thus, LCBI is zero for linear samples and is above zero for polyethylene containing
long chain branching. A high level of LCB is encountered with LCBI above 0.8.
Instead of determining intrinsic viscosity from the relative viscosity at 0.2 dg/min as
explained in their publication, we calculate intrinsic viscosity value via solution
(expressed in dl/g) in terms of weight average molecular weight Mw (expressed in
Da) obtained by size exclusion chromatography (SEC) with equation

Zero shear viscosity (η0) (expressed in Pa.s) is also related to Mw (expressed in Da)
by equation

Zero shear viscosity is estimated by fitting with Carreau-Yasuda flow curve at 190°C,
obtained by oscillatory shear rheoiogy on ARES equipment in the linear
viscoelasticiiy domain. Circular frequency (W in rad/s) varies from 0.05-0.1 rad/s to
250-500 rad/s and the shear strain is typically 10 %.
The intrinsic viscosity inferred from rheoiogy can thus be expressed as

wherein x, b and n are fitting parameters called relaxation time, breadth parameter
and power-law parameter, respectively.

The LCBl is thus rewritten as

In order to increase the accuracy in estimating zero shear viscosity, a frequency
sweep experiment having a typical range of 0.1-250 rad/s, is combined with a creep
experiment, in order to extend the frequency range to values down to 10-4 s-1 or
lower, and taking the usual assumption of equivalence of angular frequency (rad/s)
and shear rate.
Frequency sweep experiments are performed using small parallel plates having a
diameter of 8 mm that allow flow curve determination with as little as 0.1 g PE. Also,
most tests are conducted at a temperature of 2309C for polymers that do not exhibit
homogeneous flow below that temperature.
Thus, LCBl is derived at a temperature of 230°C using extrapolated shear viscosity at
0.001 s"1 as follows.

The subscript 230 recalls that LCBl is determined from frequency sweep experiments
conducted at 230°C.
The relationship between viscosity and Mw is established as usual with a series of
linear polyethylene. The viscosity/Mw relationship was established with a series of 15
linear PE having a polydispersity index betxeen 2 and 18.
ZN or metallocene-produced polyethylene known to be linear have a LCBl of 0 +/
0.1. Thus, PE with LCB are detected above LCBl of 0.1-0.2

List of accompanying figures.
Figure 1 represents the molecular weight distribution of the polyethylene obtained in
examples.
Figure 2 represents the molecular weight distribution of the polyethylenes obtained in
examples 9 and 11.
Examples-
Preparation of catalyst component
Synthesis of the liaand 1.
Step l.
The beta-diimine was synthesised according to the published procedure of Feldman
and al. (Organometallics 1997,16, p. 1514).
Step 2.
760 mg (3 mmol) of 2-bromomethylpyridine.HBr and 436 mg (3.15 mmbl) of
potassium carbonate weredegassed under vacuum for 1 hour. 10 mL of dry acetone
were added and the mixture was stirred under argon for 6 hours at room temperature
(about 25 °C). The solvent was removed and the 2-bromomethylpyridine was
extracted with 3 x 10 mL of diethyl ether under inert atmosphere. The solvent was
removed to afford a pink oil with quantitative yield.
Step 3.
1.26 g (3 mmol) of beta-diimine were dissolved in 15 mL of dry THF under argon. The
solution was cooled to a temperature of -20°C and 2 mL (3.15 mmol) of n-BuLi (1.6
M in hexane) were added dropwise. The colourless solution turned immediately to
bright yellow and was stirred at room temperature for 30 minutes. The solution was
cooled to a temperature of -20°C and a solution of 2-bromomethylpyridine in 10 mL
of dry THF was added by canula. The solution was allowed to warm to room

temperature and was stirred overnight, before being heated at 80°C for 6 hours
under reflux. After that time, the solvent was evaporated to dryness. The residue was
taken with 10 mL of dichloromethane and filtered over neutral alumina. The solution
was evaporated to afford a yellow oil purified by column chromatography (SiO2,
pentane:diethyl ether 95:5 to 80:20). 910 mg of the expected product were obtained
as pale yellow oil containing isomers 1a and 1b, with a yield of 60 %.

The isomers were characterised as follows:
C35H47N3
M=509.77 g.mol-1
1H NMR (500 MHz, CDCI3) results:
Isomer 1a: 8= 1.10 (m, 12H, CH3 /Pr), 1.21 (dd, 12H, J=6.8 Hz, CH3 /Pr), 1.92 (s, 6H,
CH3CN), 2.53 (sept, 2H, J=6.8 Hz, CH /Pr), 2.60 (sept, 2H, J=6.8 Hz, CH /Pr), 3.65
(d, 2H, J=7.5 Hz, CH2), 4.70 (t, 1H, J=7.5 Hz, CH), 7.11 (m, 2H, CH para Ph), 7.17
(br s, 4H, CH meta Ph), 7.22 (m, 1H, H5 pyr), 7.38 (d, 1H, J=7.5 Hz, H3 pyr), 7.66
(td, 1H, J=7.5 Hz, J=1.8 Hz, H4 pyr), 8.66 (d, 1H, J=5 Hz, H6 pyr).
Isomer 1b: 8=1.07 (m, 12H, CH3/Pr), 1.13 (d, 12H, J=6.9 Hz, CH3/Pr), 1.78 (s, 6H,
CH3CN), 3.20 (sept, 4H, J=6.9 Hz, CH /Pr), 4.06 (s, 2H, CH2), 7.09 (m, 2H, CH para
Ph), 7.13 (m, 4H, CH meta Ph), 7.18 (m, 1H, H5 pyr), 7.33 (d, 1H, J=7.8 Hz, H3 pyr),
7.68 (m, 1H, H4 pyr), 8.61 (d, 1H, J=5 Hz, H6 pyr).
Preparation of Fe(ll) complex 2.
210 mg (0.4 mmol) of beta-diimine-methylpyridine (1a and 1b) and 84 mg (0.4 mmol)
of iron (II) chloride tetrahydrate were degassed under vacuum for 1 hour. 10 mL of
dry tetrahydrofuran (THF) were added and the mixture was stirred under argon
overnight at room temperature. The solid was filtered off and the filtrate was
concentrated to dryness to afford 228 mg of Fe(ll) complex 2 as a brown-yellow

powder with a yield of 87%. It had formula C35H47Cl2FeN3 and a molar weight of
636.51 g.mol -1.

Mass spectroscopy: ESI (Electron Spray lonisation), solvent = CH3CN: m/z = 601.28
[M-CI]+. The calculations for C35H47FeClN3 gave a value of 600.2808.
Preparation of Cr(III) complex 3.
210 mg (0.4 mmol) of beta-diimine-methylpyridine and 162 mg (0.4mmol) of
chromium (III) chloride tetrahydrofuran were degassed under vacuum for 1 hour. 10
mL of dry tetrahydrofuran were added and the mixture was stirred under argon
overnight at room temperature. The solid was filtered off and the filtrate concentrated
to dryness to afford 274 mg of Cr(lll) complex 3 as a pink powder with a yield of 95
%. It had formula C35H47Cl3CrN3 and a molar weight of 668.13 g.mol-1.

Mass spectroscopy: ESI (Electron Spray lonisation), solvent = CH3CN: m/z = 631.25
[M-Cfj+. The calculations for C35H47CrCl2N3 gave a value of 631.2552.
Preparation of Co(II) complex 4.

51 mg (0.1 mmol) of beta-diimine-methylpyridine (1a and 1b) and 13 mg (0.1 mmol)
of cobalt (II) chloride were degassed under vacuum for 1 hour. 5 ml_ of dry
dichloromethane were added and the mixture was stirred under argon overnight at
room temperature. The solid was filtered off and the filtrate was concentrated under
vacuum to approximately 2 ml_. 20 mL of dry pentane were added to precipitate the
complex. The solvent was removed by filtration under argon and the resulting powder
washed twice with 5 mL of dry pentane. The solid was dried under vacuum to afford
44 mg of Co(ll) complex 4 as a green powder with a yield of 69%. It had formula
C35H47CI2C0N3 and a molar weight of 639.61 g.mol-1.

Preparation of Fe(III) complex 5.
51 mg (0.1 mmol) of beta-diimine-methylpyridine (1a and 1b) and 13 mg (0.1 mmol)
of iron (III) chloride were degassed under vacuum for 1 hour. 5 mL of dry
tetrahydrofuran (THF) were added and the mixture was stirred under argon overnight
at room temperature. The solid was filtered off and the filtrate was concentrated to
dryness to afford 45 mg of Fe complex 5 as a brown-yellow powder with a yield of
67%. It had formula C35H47Cl3FeN3 and a molar weight of 671.97 g.mol-1.

Synthesis of ligands 6
Using the procedure described for ligand 1 (step 1, 2 and 3), ligand 6 was obtained
with a yield of 61%.

1H NMR (500 MHz, CDCI3)■: δ = 1.26 (s, 18H, CH3 ffiu), 2.00 (s, 6H, CH3CN), 3.63 (d,
2H, J=7.5 Hz, CH2), 4.44 (t, 1H, J=7.5 Hz, CH), 6.25 (d, 2H, J=7.5 Hz), 7.05 (m, 6H),
7.34 (t, 2H, J=7.5 Hz), 7.62 (t, 1H, J=7.5 Hz), 8.59 (d, 1H, J=5 H).
Synthesis of ligands 7
Using the procedure described for iigand 1 (step 1, 2 and 3), iigand 7 was obtained
with a yield of 41%.

1H NMR (500 MHz, CDCI3) : δ= 1.80 (s, 6H, CH3), δ= 1.84 (s, 12H, CH3), 2.25 (s,
6H, CH3), 3.60 (d, 2H, J=7.5 Hz, CH2), 4.53 (t, 1H, J=7.5 Hz, CH), 6.90 (s, 4H), 7.1-
7.25 (m, 1H), 7.30-7.80 (m, 3H), 8.58 (m, 1H).
Preparation of complexes 8
Using the procedure described for complex 3, complex 8 was obtained with a yield of
68%.

Preparation of complexes 9
Using the procedure described for complex 3, complex 9 was obtained with a yield of
63%.

Preparation of complex 10.
150 mg (0,3 mmol) of ligand 1 and 36 mg (0.3mmol) of chromium (II) chloride were
degassed under vacuum for 1 hour. 10 mL of dry tetrahydrofuran were added and
the mixture was stirred under argon overnight at room temperature. The reaction
mixture was concentrated to 2ml and 10 mL of pentane was added. The solid was
filtered off and washed twice with 5mL of pentane. The solid was dried to afford 186
mg of Cr(ll) complex 10 as a green powder with a yield of 58 %.

Preparation of the complexes 11
Using the procedure described for complex 10, complex 11 was obtained with a yield
of 37%,

Preparation of the complexes 12
Using the procedure describe for complex 10, complex 12 was obtained with a yield
of 46%.

High pressure polymerisation of ethylene.
Ethylene polymerisation reactions were performed in a 20 mL stainless steel
autoclave containing a glass insert, fitted with mechanical stirring, external
thermocouple and pressure gauge and controlled by computer. In a typical reaction
run, 4 mL of dry solvent (toluene or n-heptane) were introduced into the reactor, the
temperature was raised to 50 oC and the ethylene pressure was raised to 15 bar and
continuously fed. In a argon-filled glove box, about 5 umol of the appropriate catalyst
were weighted, activated with an amount of methylaluminoxane (MAO 30 % wt in
toluene) or tetraisobutyldialuminoxane (IBAO 10 wt % in toluene) activator in an
amount appropriate to obtain a ratio [Al]:[M3 of 2000 and diluted with toluene to a final
volume of 2 mL. 200 µL of the solution of the activated catalyst were placed inside
the reactor. The injection loop was rinsed with 800 uL of solvent. After 1 hour or a
consumption of 12 mmol of ethylene, the reaction was quenched with isopropanol
and an aliquot analysed by gas chromatography. The gas chromatographic analysis
of the reaction products were performed on a Trace GC apparatus with a Petrocol
capillary column (methyl silicone, 100 m long, i.d. 0.25 mm and film thickness of 0.5
urn) working at a temperature of 35°C for 15 min and then heated to a temperature of
250 °C at a heating rate of 5sC/min. The remaining reaction mixture was quenched
with MeOH / HCI and the polymer was filtered, washed with methanol and dried at a
temperature of 50°C, under vacuum, for a period of time of 24 hours.
The reaction conditions for each example are displayed in Table I and the results are
displayed in Table II and in Table III.

Oligomerisation of 1-haxene.
In a argon-filled glove box, about 7.5 µmol of the appropriate catalyst were weighted,
activated with an amount of methylaluminoxsne (MAO) activator, 30 % wt in toluene,
suitable to give a [AI]:[M] ratio of 2000 and diluted with toluene to a final volume of
4.5 mL 3 mL of the solution of the activated catalyst were placed in a Schlenk tube
containing 5 mL of 1-hexene. The solution was stirred at a temperature of 30°C for 1
hour. The mixture was quenched with slightly acidified methanol. The layers were
separated. The toluene layer was concentrated to dryness to afford oligomers. The
gas chromatographic analysis of the reaction products was done on a Trace GC
apparatus with a Petrocol capillary column (methyl silicone, 100 m long, i.d. 0.25 mm
and film thickness of 0.5 µm) working at a temperature of 100°C for 4 min and then
heated to a temperature of 250 °C at a heating rate of 8°C/min.
The results are displayed in Table IV.

Ethylene polymerisation reactions were carried out in a 130 ml stainless steel
autoclave equipped with mechanical stirring and a stainless steel injection cylinder. In
a typical reaction run, the reactor was first dried under nitrogen flow at 100PC during
10 min. Then it was cooled down to the reaction temperature (50° or 85°C) and 35 ml
of isobutane were introduced into the reactor with a syringe pump, followed by the
comonomer if required. The pressure was adjusted to the desired value (14.8 or 23.8
bar) with ethylene. In an argon-filled glove box, 300 mg of the supported catalyst
(complex 3 deposited on MAO impregnated silica, at 2 wt % based on the total
weight of the supported catalyst), the cocatalyst and 0.6 ml of n-hexane were placed
into the injection cylinder. The valve was closed and the cylinder was connected to
the reactor under nitrogen flow. The active catalyst mixture was then introduced into
the reactor with 40 ml of isobutane. After 30 minutes or 1 hour, the reactor was
cooled down to room temperature and slowly depressurised, and the polymer was
recovered. The polymerisation results are displayed in Table V.

The obtained polymers were characterized by GPC in TCB at 140°C, by DSC, by
RDA at 230°C and by 13C NMR in TCB at 135°C. The results are displayed in table
VI and figure 2.

The 13C NMR analysis for examples 10 and 12, showed the absence of short
chain branching (less than 0.1 mol%) and the presence of saturated and vinylic ends.
It can thus be seen that the polymers according to the present invention have a very
high level of long chain branching, in fact much larger than the polymers prepared
with bis-tetrahydroindenyl metallocene catalyst components known to have a high
level of high chain branching and who exhibit a LCBI typically of from 0.5 to 1.

WE CLAIM:
1. A catalyst component of formula IV

wherein R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10 are each independently selected
from hydrogen, unsubstituted or substituted hydrocarbyl or inert functional group
selected from halo, ester, ether, amino, imino, nitro, cyano, carboxyl, phosphate,
phosphonite, phosphine, phosphinite, thioether and amide, and wherein R1 and R2
are unsubstituted or substituted alkyl groups, unsubstituted or substituted aryl
groups, unsubstituted or substituted cycloalkyl groups, R3 and R4 are unsubstituted
or substituted alkyl groups, unsubstituted or substituted aryl groups, unsubstituted or
substituted cycloalkyl groups, R5 is hydrogen or methyl, R6, R7, R8, R9 and R10 are
unsubstituted or substituted alkyl groups, unsubstituted or substituted aryl groups,
unsubstituted or substituted cycloalkyl groups, and two groups can be linked
together to form further ring or rings, with the restriction that R1 and R3, R2 and R4,
and R9 and R10, cannot be simultaneously oxazoline, and wherein Z is selected from
N, P, O or S and m is the valence of Z minus one, wherein M is a metal selected
from Ti, Zr, Hf, V, Cr, Mn, Fe, Co, Ni, Pd or rare earth, wherein X' are the same or
different and are halogen or substituted or unsubstituted hydrocarbyl and wherein n
is the valence of M and characterised in that the complex folds around the carbon
atom preceding Z to allow joining Z to metal M in order to form a three dimensional
scorpion-like structure.
2. The catalyst component as claimed in claim 1 wherein R1 and R2 are
unsubstituted or substituted phenyl groups.

3. The catalyst component as claimed in claim 1 wherein R3 and R4 are
unsubstituted or substituted alkyl groups.
4. The catalyst component as claimed in claim 3 wherein R3 and R4 are linked
together to form a cyclohexyl ring.
5. The catalyst component as claimed in any one of the preceding claims wherein
R8, R9 and R10 can be linked together to form a ring, for example a pyridine, a
quinoline, an isoquinoline, a pyrrolyl, a furyl or a thiophenyl group.
6. The catalyst component as claimed in any one of the preceding claims wherein
M is Cr.
7. A method for preparing the catalyst component as claimed in any one of claims
1 to 6 by complexing a ligand of formula I

with a metallic salt MX'n in a solvent, wherein all R1, R2, R3, R4, R5, R6, R7, R8.R9
and R10 and M are as defined in the preceding claims, wherein X is halogen or
substituted or unsubstituted hydrocarbyl and n is the valence of M.
8. An active catalyst system comprising the catalyst component as claimed in any
one of claims 1 to 6 and an activating agent having an ionising action as herein
described and optionally a cocatalyst selected from triethylaluminium,
triisobutylaluminium, tris-n-octylaluminium, tetraisobutyldialuminoxane or diethyl zinc.

9. An active catalyst system comprising the tridentate catalyst component as
claimed in any one of claims 1 to 6, an activating support and optionally a cocatalyst
selected from triethylaluminium, triisobutylaluminium, tris-n-octylaluminium,
tetraisobutyldialuminoxane or diethyl zinc.
10. A method for oligomerising or homo- or co-polymerising ethylene and alpha-
olefins that comprises the steps of:
a) injecting the active catalyst system of claim 8 or claim 9 into the reactor;
b) injecting the monomer and optional comonomer either before or after or
simultaneously with step a);
c) maintaining under polymerisation conditions at a temperature from 10 to 100 °C
and a pressure fom 0.5 to 50 bars;
d) retrieving oligomers or a polymer.
11. The method as claimed in claim 10 wherein the monomer and optional
comonomer are selected from ethylene, propylene or 1-hexene.
12. The method as claimed in claim 10 or claim 11 wherein the optional
comonomer is a polar functionalised alpha-olefin.

ABSTRACT

SINGLE SITE CATALYST SYSTEMS HAVING A
SCORPION-LIKE STRUCTURE
The inventions discloses a catalyst component of formula IV

wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, R10,Z, MX'n, m and n are as defined in the
specification.
The invention is also for a method for preparing said catalyst component, a catalyst
system comprising said catalyst component and a method of oligomerising, homo-
or co-polymerising ethylene and alpha-olefins with said catalyst system.

SINGLE SITE CATALYST SYSTEMS HAVING A SCORPION-LIKE STRUCTURE

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