POLYMERISATION CATALYST

Abstract: A catalyst composition suitable for use in the polymerisation of olefins comprises a discrete metal complex having chelating ligands comprising at least one atom from O, S, N and P bound directly to the metal. The complexes are used in the presence of Lewis acids and may be exemplified by bis(cyclopentadienyl) zirconium complexes. Typical chelating ligands include acetylacetonate and the complexes have the particular advantages of not requiring traditional activators such as MAO.

Description: POLYMERISATION CATALYST The present invention relates to certain novel discrete metal complexes, their preparation and to their use in catalyst compositions suitable for the polymerisation of olefins. In particular the invention relates to catalyst compositions comprising a discrete metal complex and an activator The use of certain transition metal compounds to polymerise 1 -olefins, for example, ethylene, is well established in the prior art The use of Ziegler-Natta catalysts produced by activating titanium halides with organometallic compounds such as triethylaluminium is fundamental to many commercial processes for manufacturing polyolefins Over the last twenty or thirty years, advances in the technology have lead to the development of Ziegler-Natta catalysts which have such high activities that that olefin polymers and copolymers containing very low concentrations of residual catalyst can be produced directly in commercial polymerisation processes The quantities of residual catalyst remaining in the produced polymer are so small as to render unnecessary their separation and removal for most commercial applications. Such processes can be operated by polymerising the monomers in the gas phase, or in solution or in suspension in a liquid hydrocarbon diluent. Polymerisation of the monomers can be carried out in the gas phase (the "gas phase process"), for example by fluidising under polymerisation conditions a bed comprising the target polyolefin powder and particles of the desired catalyst using a fluidising gas stream comprising the gaseous monomer In the so-called "solution process" the (co)polymerisation is conducted by introducing the monomer into a solution or suspension of the catalyst in a liquid hydrocarbon diluent under conditions of temperature and pressure such that the produced polyolefin forms as a solution in the hydrocarbon diluent In the "slurry process" the temperature, pressure and choice of diluent ate such that the produced polymer forms as a suspension in the liquid hydrocarbon diluent These processes are generally operated at relatively low pressures (for example 10-50 bar) and low temperature (for example 50 to 150°C) Commodity polyethylenes are commercially produced in a variety of different types and grades. Homopolymerisation of ethylene with transition metal based catalysts leads to the production of so-called "high density" grades of polyethylene. These polymers have relatively high stiffness and are useful for making articles where inherent rigidity is required Copolymerisation of ethylene with higher 1 -olefins (eg butene, hexene or octene) is employed commercially to provide a wide variety of copolymers differing in density and in other important physical properties Particularly important copolymers made by copolymerising ethylene with higher 1 -olefins using transition metal based catalysts are the copolymers having a density in the range of 0 91 to 0 93 These copolymers which are generally referred to in the art as "linear low density polyethylene" are in many respects similar to the so called "low density" polyethylene produced by the high pressure free radical catalysed polymerisation of ethylene Such polymers and copolymers are used extensively in the manufacture of flexible blown film An important feature of the microstructure of the copolymers of ethylene and higher 1 -olefins is the manner in which polymerised comonomer units are distributed along the "backbone" chain of polymerised ethylene units The conventional Ziegler-Natta catalysts have tended to produce copolymers wherein the polymerised comonomer units are clumped together along the chain To achieve especially desirable film properties from such copolymers the comoπomei units in each copolymer molecule are preferably not clumped together, but are well spaced along the length of each linear polyethylene chain In recent years the use of discrete metal complexes based on transition metals has provided catalysts with potentially high activity and capable of providing an improved distribution of the comonomer units Such complexes are known as metallocenes and may be exemplified by biscyclopentadienyl transition metal complexes The use of these discrete metal complex based olefin polymerisation catalysts is now well established Examples of such complexes may be found in EP 129368, EP 206794, and EP 260130 Typically the metallocene complex comprises a bis(cyclopentadienyl) zirconium complex for example bis(cyclopentadie yl) zirconium dichloride or bis(tetramethylcyclopentadιenyl) zirconium dichloride In such catalyst systems the discrete metal complex is used in the presence of a suitable activator. The activators most suitably used with such metallocene complexes are aluminoxanes, most suitably methyl aluminoxane or MAO. Other suitable activators are perfluorinated boron compounds. More recently transition metal complexes having a constrained geometry have been used as components of olefin polymerisation catalyst systems. Such complexes are described in EP 420436 and EP 416815. Such complexes are also used in the presence of the activators described above for example aluminoxanes. It would however be beneficial to improve the performance of discrete metal complex based olefin polymerisation catalysts. It would also be beneficial to use simpler and less costly activators with these discrete metal complexes, or to use lower activator concentrations. EP 5 19746 describes catalyst systems for olefin polymerisation comprising bis(cyclopentadienyl) transition metal complexes having alkylsulphonate ligands and organoaluminium oxy-compounds. Such systems require the use of aluminoxanes as activators. EP 591756 describes a polymerisation catalyst system comprising a polycation complex of a metallocene complex with an ionic compound. The polycation complex may for example be a bis(cyclopentadienyl) zirconium ditriflate. EP 598134 describes titanium complexes having chelate forming ligands, for example acetylacetonate groups, which may be used as catalysts for the polymerisation of olefins together with compounds capable of forming ionic complexes with the titanium complex. This reference also specifies titanocenes containing chelate forming ligands, for example acetylacetonate groups, which may be used as catalysts together with compounds capable of forming ionic complexes with the metallocene. The resultant catalyst system is used in the presence of organoaluminium compounds. EP 472741 describes olefin polymerisation catalysts comprising transition metal complexes having coordinated ligands for example diketones together with aluminoxanes. The complexes described therein do not contain cyclopentadienyl ligands and the valency of the metal is typically satisfied with dichloride ligands. The preparation of a number of complexes containing similar diketonic ligands has been reported in the prior art Angew. Chem. Int. Ed. Engl. ( 1996), 35( 1 ), 80-2 describes the preparation of an acetylacetonato zirconocene borate using a preformed zirconocene-betaine cation Organometal cs ( 1994), 13( 10), 3897-902 describes the preparation of (acetylacetonato)η- 1 -(pyrazole-N) zirconocene tetraphenylborate Bull Soc Chim Fr ( 1984), (3-4, Pt 1 ), 1 13- 14, Z Naturforsch , B Anorg. Chem Org Chem (1984), 39B(5), 604-6, Synth React Inorg Met -Org Chem (1983), 13(8), 1059-65, Synth React lnorg Met -Org Chem ( 1983), 13(3), 357-66 and Monatsh Chem (1983), 1 14(4), 399-405 describe the preparation of metallocene acetylacetonato xanthates amd carbamates Izv. Akad Nauk SSSr, Ser. Khim ( 1978), ( 1 1 ), 2645-7 describes the preparation of Cp 2 Zr(PhCOCHCOPh)(CI) We have now found catalyst systems based on discrete metal complexes comprising certain hetero-atom containing chelating ligands which are suitable for the polymerisation of olefins Furthermore a particulai advantage of these catalyst systems is that they may be used in the absence of traditional aluminoxane activators Thus according to the present invention theie is provided a catalyst composition suitable for use in the polymerisation of olefins said composition comprising (A) a neutral discrete metal complex having the geneial formula (L) p MY n X m Z C] where L represents a Iigand which remains bound to M under olefin polymerisation conditions, M is a Group IIIA element oi , Gi oup I11B, IVB, VB, VIB or VIII transition metal (CAS version of the Periodic Table, Cotton & Wilkinson " Ed ), Y is a chelating Iigand comprising at least one atom from O, S, N and P bound directly to M, X is the same as Y or is chosen fiom the gioup compiising hydride hydrocarbyl, substituted hydiocarbyl, hahde, peichloiate, substituted sulphonate, trifluoromethane sulphonate, methane sulphonate, fluoiosulphonate, aryl sulphonate, bιs(tι ifluoi omethylsulfonyl)methyl, l)benzyl, bis(trifluoromethylsulfonyl)amιde, alkoxide, aryloxide, tetiaal ylboi te, tetraarylborate, tetraphenylborate, substituted tetraphenylborate, tetrakis(pentafluorophenyl)borate, tetrakis[bis(3,5-ditrifluoromethyl)phenyl]borate, tetrafluoroborate, hexafluorophosphate or pentafluorotellurate, Z is a neutral Lewis base, ■ n > or = 1 p > or = 1 m > or = 0 and q > or = 0 , provided that n, m, p and q are integers or zero which satisfy the valency of the metal and (B) one or more Lewis acids Illustrative but non-limiting examples of suitable discrete metal complexes for use in the catalyst composition of the present invention are those having the following Y groups in the above general formula acetylacetonate β-diketonate, β-ketoester β-ketoaldehyde dithioacetylacetonate HC(SO 2 CF 3 ) 2 - carboxylate carbamate thiocarboxylate dithiocarboxylate thiocarbamate dithiocarbamate xanthate thioxanthate phosphinate thiophosphinate dithiophosphinate dialkyldithiophosphate amidinate bisimidazolate phosphate sulphurdiiminate ami date tropolonate oxalate oxalate ester nitrate nitrite carbonate squarate croconate sulphinate sulphate sulphite fluorosulphate hydroxamate thiohydroxamate dithiohydroxamate The preferred complexes are those in which the Y group comprises at least one O atom bound directly to the metal Particularly suitable complexes are those in which the Y group is a β- diketonate or β-ketoester for example acetylacetonate or substituted acetylacetonates such as fluorinated derivatives Particularly suitable complexes are those in which p is 1 or 2 and M is a Group IVB metal eg zirconium or titanium Particularly suitable complexes are those in which the X group is hydrocarbyl, halide or trifluoromethane sulphonate (triflate) Suitable discrete metal complexes for use in the present invention include metallocene complexes comprising bis cyclopentadienyl ligands such as those disclosed for example in EP 129368 or EP 206794 Particularly suitable metallocene complexes are those having the general formula (L) p MY n X m Z q where L represents an unsubstituted or substituted cyclopentadienyl Iigand, M is a Group IVB, VB, VIB or Vlll transition metal (CAS version of the Periodic Table, Cotton & Wilkinson 5 l Ed.), Y is a chelating Iigand comprising at least one atom from O, S, N and P bound directly to M, X is the same as Y or is chosen from the group comprising hydride, hydrocarbyl, substituted hydrocarbyl, halide, perchlorate, substituted sulphonate, trifluoromethane sulphonate, methane sulphonate, fluorosulphonate, aryl sulphonate, bis(trifluoromethylsulfonyl)methyl, bis(trifluoromethylsulfonyl)benzyl, bis(trifluoromethylsulfonyl)amide, alkoxide, aryloxide, tetraarylborate, tetraphenylborate, substituted tetraphenylborate, tetrakis(pentafluorophenyl)borate, tetrakis[bis(3,5-ditrifluoi"omethyl)phenyl]borate, tetrafluoroborate, hexafluorophosphate, pentafluorotellurate, Z is a neutral Lewis base, n > or = 1 p > or = 1 m > or = 0, and q > or = 0 provided that n, in, p and q are integers or zero which satisfy the valency of the metal. The cyclopentadienyl Iigand may be substituted by alkyl, aryl, alkenyl, arylalkyl or alkylaryl groups or two substituents may be joined together to form a fused ring for example indenyl. Preferred cyclopentadienyl ligands are substituted by methyl groups. When p is 2 ie when there are two cyclopentadienyl groups present they may joined together via a bridging group for example by a group of formula ( 2 Z)„ where Z is silicon, germanium or carbon, p is from 1 -8 and R is hydrogen or a group selected from hydrocarbyl or combinations thereof. Preferred complexes are those wherein M is zirconium, titanium or hafnium, p is 2 and n is 1 or 2. Also suitable for use in the present invention are complexes having a constrained geometry such as those disclosed in EP 4168 1 or EP 420436 For example complexes having the following general formula may be suitable. / / Cp* M / \ (Y)„ (X)„ wherein' Cp* is a single η5-cyclopentadιenyl oi η5-substιtuted cyclopentadienyl group optionally covalently bonded to M through Z-P and corresponding to the formula wherein R each occurrence is hydrogen oi a moiety selected from halogen, alky], aryl, haloalkyl, alkoxy, aiyloxy, silyl groups, and combinations thereof of up to 20 non-hydrogen atoms, or two or more R groups together form a fused ring system, M is zirconium, titanium or hafnium bound in an η5 bonding mode to the cyclopentadienyl or substituted cyclopentadienyl group and is in a valency state of +3 or +4. Z is a divalent moiety comprising oxygen, boron, or a member of Group IVA of the Periodic Table of the Elements (CAS Version of the Periodic Table. Cotton & Wilkinson 5 1 " Ed ), P is a linking group covalently bonded to the metal comprising niti ogen. phosphorus, oxygen or sulfur, or optionally Z and P together form a fused ring system, and X, Y, n and m are as defined above such that n and m satisfy the valency of M. Preferred complexes are those in which the metal M is titanium, P is nitrogen and Z is silicon. Other suitable complexes which may provide the L Iigand of the present invention are complexes described in EP 672676 and EP 757996. Such complexes comprise a cyclooctatetraenyl (or COT) Iigand and hence represent the above formula when L is cyclooctatetraenyl. Examples of suitable Lewis acids suitable for use in the present invention are alkyl aluminium compounds eg trimethyl aluminium, triisobutylaluminium, aryl aluminium compounds eg tris(pentafluorophenyl)aluminium, aluminium hydrides eg aluminium trihydride and mixed hydride/ary l/alky I aluminium compounds eg di- isobutyl aluminium hydride, mono(pentafluorophenyl)di-isobutylaluminium Also suitable are alkyl aluminium halides eg dimethyl aluminium chloride or alkyl aluminium dihalides eg methyl aluminium dichloride or ethyl aluminium dichloride. Also suitable for use as Lewis acids are alkyl or aryl borons, boron halides and hydrides, macrocyclic boron compounds eg boracyclododecane, alkyl magnesiums or magnesium halides are also suitable. Particularly suitable are tris(pentafluorophenyl) boron and triisobutyl boron. Aryloxy aluminium compounds eg (2,7-dimethyl- 1 ,8- biphenylenedioxy)bis(di-iso-butylaluminium) and aryloxy boron compounds eg catecholborane are also suitable. The ratio of the one or more Lewis acids to the discrete metal complexes according to the present invention is 0.2 : 10,000 preferably 0 2 ; 5000 The catalyst compositions according to the present invention may be suitably supported. For example the discrete metal complexes may be impregnated on a catalyst support for example silica, alumina, or magnesium chloride Preparation of supported catalysts may be carried out by conventional techniques The catalyst compositions according to the present invention may also comprise another catalyst component for example a Ziegler catalyst or another metal complex For example a multisite catalyst composition may be used comprising a supported metal complex and activator according to the present invention together with a Ziegler catalyst for example a catalyst comprising atoms of titanium, magnesium and halogen. Such multisite catalysts may be prepared by conventional routes The complexes according to the present invention may also be used if required in the presence of the traditional activators for example aluminoxanes in particular methyl aluminoxane The complexes according to the present invention may also be used in the presence of ionising ionic compounds for example trityl tetrakis(pentafluorophenyl)borate, dimethylanilinium tetrakis(pentafluorophenyl)borate, lithium tetrakis(pentafluorophenyl)borate, trityl tetraphenylborate, tetrafluoroboric acid and the like The present invention also provides a process for the production of polyolefins, in particular homopolymers of ethylene and copolymers of ethylene with minor amounts of at least one C3 to CI O, preferably C3 to C8 alpha-olefin The process comprises contacting the monomei or monomers, optionally in the presence of hydiogen, with the catalyst composition according to the invention at a temperatui e and pressui e sufficient to initiate the polymei isation reaction Suitably the alpha olefin may be propylene, butene- 1 , hexene- 1 , 4-methyl pentene- 1 and octene- 1 The olefin polymerisation catalyst compositions according to the present invention may be used to produce polymers using solution polymerisation, slurry polymerisation or gas phase polymerisation techniques Methods and apparatus for effecting such polymerisation reactions ate well known and described in, for example. Encyclopaedia of Polymer Science and Engineering published by John Wiley and Sons, 1 87, Volume 7, pages 480 to 488 and 1 88, Volume 12, pages 504 to 541 The catalyst according to the present invention can be used in similar amounts and under similar conditions to known olefin polymeiisation catalysts The polymerisation may optionally be carried out in the presence of hydrogen Hydrogen or other suitable chain transfer agents may be used to control the molecular weight of the produced polyolefin According to anothei aspect of the pi esent invention there are provided novel metal complexes having the general formula (L) 2 M Y X Z / / L MXY wherein L repiesents an unsubstituted or substituted cyclopentadienyl Iigand, Z is a divalent moiety comprising oxygen boion, or a member of Group IVA of the Periodic Table of the Elements (CAS Version of the Periodic Table Cotton & Wilkinson 5"' Ed) P is a linking gioup covalently bonded to the metal comprising nitrogen, phosphorus, oxygen oi sulphui, optionally Z and P foim a fused nng system X is SO-sCFi or hydiocarbyl Y is RCOCHCOR wherein R, which may be the same oi difϊeient, is hydiocaibyl or substituted hydrocaibyl, foi example CH„ C 2 H 5 , or CF„ C(CH-,)-, or OCH ^ CH, In particulai complexes having the following foimula are disclosed (l,3-(CH 2 C 5 H 2 Zι(CH,COCHCOCH,)SO,CF (1,3-(CH 2 C 5 H 2 ZI(CF 1 COCHCOCF SO CF (1,3-(CH 2 C S H,) 2 ZΓ(CH,COCHCOOCH 2 CH SO*CF, (CH 2 Si((CHι) 4 C (NC(CH Tι(CF,COCHCOCF SO,CF, (l,3-(CH,) 2 C 5 FL) 2 Zr((CH.);CCOCHCOC(CH,),)SO,CF-, (C s Hj) 2 Zr(CH,COCHCOCH CHi According to a furthei aspect of the present invention there is piovided a method of piepaiing the novel complexes compiising reacting a piecursoi complex that contains at least one hydiocaibyl substituent attached to the metal for example Cp 2 Zι(CH-,)(SOCF^) with the appiopiiate dione in a suitable solvent for example toluene oi pentane and iecoveπng the complex by filtiation or removal of solvent Thus there is provided a method for preparing complexes of formula Cp 2 -MXY by reacting a complex of formula Cp 2 M(hydrocarbyl) X with a dione of formula RCOCH 2 COR in a suitable solvent, wherein M - Zr, Ti, Hf Y = RCOCHCOR X = SO,CF 3 R = hydrocarbyl If the precursor complex contains more than one hydrocarbyl substituent and it is desired that the resulting complex also contains an hydrocarbyl substituent, then it is preferable to carry out the reaction by adding the dione dropwise to a stirred solution of the precursor complex Thus there is also provided a method for preparing complexes of formula Cp 2 M(hydrocarbyl) Y by treatment of a solution a complex of formula Cp 2 M(hydrocarbyl) 2 dropwise with a dione of formula RCOCH 2 COR wherein M = Zr, Ti, Hf Y = RCOCHCOR R = hydrocarbyl. The present invention will now be furthei illustrated by reference to the following examples Example 1 Preparation of π,3-(CH ),C s H^ ? Zr(CTLCOCHC CH )SO t CF Λ To a solution of 307 mg ( l mmol) bis ( l , -dimethylcyclopentadienyl)zirconium dimethyl in 20ml of toluene were added 88 μl ( l mol) trifluoromethanesulfonic acid The mixture was stirred for one hour, then 102 μl ( l mmol) 2,4-pentanedione were added in one portion The solvent was evaporated to dryness, and the residue recrystallised from ether/hexane 1/5 to yield 247 mg ( 1 ,3- (CH 3 ) 2 C 5 H 3 ) 2 Zr(CH COCHCOCH;)SO,CF. as light yellow crystals (47% yield) Characterised by nmr as follows H-NMR (d -toluene, ambient temperatui e) δ = 5 63 (4H, m, Cp-CH), 5 56 (2H, m, Cp-CH), 4 98 ( I H, s, acac CH), 1 85 (12H, br s, Cp-CH,), 1 67 (6H, br s, acac Me) π s C-NMR' (d' -toluene, ambient temperature, EP ' 1 -45) δ = 14 7 (CH,-Cp), 26 5 (CH,-acac), 102 3 (CH-acac), 120 7. 129 4 (CTl-Cp) 19 8 F-NMR. (d -toluene, ambient tempeiature) δ = -79 4 Example 2 Preparation of (L3-(CH^,C.H I 7 Zr(CF COCHCOCF^SOιCFι To a solution of 307 mg ( i mmol) bis(l,3-dimethylcyclopentadienyl)zirconium dimethyl in 20 ml of toluene were added 88 μl ( lmmol) trifluoromethanesulfonic acid. The mixture was stirred for one hour, then 141 μl ( l mmol) 1,1, 1,5,5,5- hexafluoro-2,4-pentanedione were added in one portion The solvent was evaporated to dryness, and the residue recrystallised from toluene/hexane 1/10 to yield 442 mg (l,3-(CH 3 ) 2 C 5 H 3 ) 2 Zr(CF 3 COCHCOCF 3 )SO 3 CF, as bright yellow crystals (70% yield) Characterised by nmr as follows ι g H-NMR (d -toluene, ambient temperature) δ = 5.99 (IH, s, hfacac), 5 72 (2H, s, Cp-CH), 5 45 (4H, s, Cp-CH), 1 86 (6H, s, Cp-CH,), 1 65 (6H, s, Cp-CH,) C-NMR (d l -toluene, ambient temperature, DEPT-45) δ = 13.83, 14 02 (CR-Cp), 92 3 1 (CH-hfacac), 1 16 286, 1 1 7 154, 123 081 (CH- Cp) 19 j . F-NMR (d' -toluene, ambient temperature) δ = -77.10, -77 39, -79 41 Example 3 Pi ep rntion of d^-fCHi^C H^^ZrfCHiCOCHCOOCH^CH^SO^CFT To a solution of 307 mg ( l mmol) bis( l ,3-dimethylcyclopentadιenyl)zirconιum dimethyl in 20 ml of toluene were added 88 μl ( l mmol) trifluoromethanesulfonic acid The mixture was stirred for one hour, then 127 μl ( lmmol) ethylacetoacetate were added in one portion The solvent was evaporated to dryness, and the residue recrystallised from toluene/hexane 1/10 to yield 442 mg ( 1 ,3- (CH3) 2 C 5 H,)2Zr(CF 3 COCHCOCF,)SO,CF, as colourless crystals (76% yield) Characterised by nmr as follows. i s H-NMR (d' -toluene, ambient temperature) δ = 5 76 (2H, s br, Cp-CH), 5 63 (2H, s br, Cp-CH), 5 51(2H, s br, Cp-CH), 4 82 ( IH, s, acac-CH), 4 46 (2H, s br, OCH.CH,), 1 90 (6H, s bi , Cp-CH,), 1 85 (6H, s br, Cp-CH,), 1 52 (3H, s, br acac-CH,), 1 09 (3H, s bi , OCH.CH,) 1 F-NMR (d' -toluene, ambient temperature) δ = -78 98 Example 4 Applying the method of example 2, with (CH 2Sι((CI-U),C\)(NC(CF ) Tι(CH3) 2 starting material, gave (CH 3 ) 2 Si((CH 3 ) 4 C 5 )(NC(CH,) 3 )Ti(CF,COCHCOCF ,)SO.CF,, characterised by nmr as follows 1 H-NMR- (d s -toluene, ambient temperature) δ = 6.15 ( IH, s, acac-CH), 2.23, 1 91 , 1 82, 1 09 ( 1211, 4s, Cp-CH. , 0 99 (9H, s, NC(CH 3 ) 3 , 0 48, 0.39 (6H, 2s, Si-CR), 19 F-NMR ' (d s -toluene, ambient temperature) δ = -76.4, -76.7, -79.2. Example 5 Preparation of π .3-rCH ιCsH >7Zι-(fCH^ CCOCHCOC CH.Λ>.- t )SO. CF 3 To a solution of 307 mg ( l mmol) bis( l ,3-dimethylcycloρentadienyl)zirconium dimethyl in 20 ml of toluene was added 88 μl ( l mmol) trifluoromethanesulfonic acid The mixture was stirred for one hour, then 208μl ( 1 inmol) 2,2,6,6- tetramethy]-3,5-heptanedione were added in one portion The solvent was evaporated to dryness, and the residue recrystallised fi om ether/hexane 1/20 to yield 53 1 mg ( 1 ,3-(CH 3 ) ? C 5 H 2 Zr((CH,),CCOCHCOC(CH,) SO,CF-, as colourless crystals (87% yield) Characterised by nnii as follows ι s H-NMR. (d' -toluene, ambient temperature) δ = 5 67 (4H, m, Cp-CH), 5 63 (2H, m, Cp-CH). 5 8 (bs, acac CH), 2 03 ( 12H, br s, Cp-CH,), 1 0 ( 18H, br s, acac 'Bu) C-NMR (d s -toluene, ambient temperature, DEP1 -45) δ = 14 6 (CH.-Cp), 27 8, 28 3 ( acac), 92 2 (CH-acac), 1 16 3, 1 17 0, 122 9 (CH-Cp) Example 6 To a solution of 920 mg (3 όmmol) bis(cyclopentadιenyl)zirconium dimethyl in 100 ml of pentane at -78°C was added 370 μl (3 όmmol) of 2,4-pentanedione di opwise with stirring The mixture was stirred for one hour befoie allowing to warm to ambient temperature A white precipitate formed which was isolated by filtration and washed with cold pentane (2 x 50ml) Yield of (CsH s ) 2 Zι (CH,COCHCOCH π was 630 mg (52% yield) Chai acterised by nmi as follows H-NMR (d 6 -benzene, ambient temperatui e) δ = 5 79 ( 10H, s, Cp), 5 08 ( H i, s, acac CH), 1 6 ! (Oi l, s, acac Cl 0 6 1 (3H, s, CIL) Polymerisations Examples 7-12 were carried out in a 1 litre capacity autoclave using isobutane as the reaction medium The reactor was heated to 85°C and thoroughly purged with nitrogen (21/min) for 90 min. The temperature was then reduced to 50°C and the reactor charged with the chosen alkylaluminium reagents and iso-butane (500ml) The mixture was stirred (200rpm) at 75°C for a minimum of 120 min and 10 bar overpressure of ethylene was then added The metal complex and other Lewis acid (if used) were then added to the reactor Ethylene was added to maintain constant reactor pressure for the duration of the run The run was terminated by rapidly venting the reactor and cooling to 20°C. Solid polymer product was washed with methanolic hydrogen chloride, rinsed with aqueous ethanol and dried (50°C, in vacuo, 16h) Details of the complexes and Lewis acids used are as follows Example 7 Triisobutylaluminium (3ml of IM solution in toluene, Aldrich) and trimethylaluminium (1ml of 2M solution in hexanes, Aldrich) were charged to the reactor, followed by (l,3-(CH 3 ) 2 C 5 H 3 ) 2 Zr(CH 3 COCHCOCH SO 3 CF 3 (0 95μmol, as prepared in example 1) Reaction time was 66 min Polymer yield was 10 22g, catalyst activity 978g polymer/mmol Zr b h Example 8 Triisobutylaluminium (4ml of I M solution in toluene, Aldrich) was charged to the reactor, followed by a mixture of ( l ,3-(CR) 2 C 5 H,) 2 Zi(CH;COCHCOCR)SO 3 CF~, (1 Oμmol, as prepared in example 1 ) and Triisobutylaluminium ( l Oμmol ) Reaction time was 60 min Polymer yield was 23 47g, catalyst activity 2347g polymer/mmol Zr b h Example 9 Triisobutylaluminium (4ml of IM solution in toluene, Aldrich) was charged to the reactor, followed by ( l (0 95μmol, as prepared in example 1 ) and B(C 6 F 5 ) 3 (Boulder Scientific, 1 425μmoI) Reaction time was 60 m Polymer yield was 15 61g, catalyst activity 1643g polymer/mmol Zr b h Example 10 Triisobutylaluminium (5ml of I M solution in toluene, Aldrich) was chaiged to the reactor, followed by ( l ,3-(CH ) 2 C 5 H 1 ) 2 Zr(CF,COCHCOCF,)SO ϊ CF-, (0 95μmol, as prepared in example 2) and B(C 6 F 5 )^ (Boulder Scientific, 0 95μmol) Reaction time was 60 mm Polymer yield was 21 61 g, catalyst activitv 2275g polymer/mmol Zr b.h Example 11 Triisobutylaluminium (4ml of IM solution in toluene, Aldrich) was charged to the reactor, followed by (l,3-(CH 3 ) 2 C 5 H 3 ) 2 Zr(CH 3 COCHCOOCH 2 CH 3 )SO 3 CF, (0.95μmol; as prepared in example 3) and B(C6F 5 )3 (Boulder Scientific, 0 95μmol) Reaction time was 60 min Polymer yield was 12.19g, catalyst activity 1283g polymer/mmol Zr b h Example 12 Triisobutylaluminium (4ml of IM solution in toluene, Aldrich) was charged to the reactor, followed by (l,3-(CH,) 2 C 5 Hι) 2 Zr(CF,COCHCOCF SO,CF-, (1 Oμmol, as prepared in example 2) and MAO (Al Zr ratio 600 1 ) Reaction time was 60 min Polymer yield was 48.8g catalyst activity 4880g polymer/mmol Zr b h Example 13 Triisobutylaluminium (4ml of I M solution in toluene, Aldrich) was charged to the reactor, followed by ( l,3-(CH 3 ) 2 C 5 R) 2 Zr(CH3COCHCOCH3)SO,CF3 (0 95μmol, as prepared in example 3) and [CPh3][B(C 6 F 5 ) 4 ] (Boulder Scientific, 1 43μmol) Reaction time was 60 min Polymer yield was 37 8g, catalyst activity 3979g polymer/mmol Zr b h Example 14 To a solution of (C < H 5 ) 2 Zr(CrhCOCHCOCrh)Me ( 17 5 mg, 0 05 mmol, as prepared in example 6) and B^ ό Fs)^ (25 6 mg, 0 05 mmol) in 40ml toluene was added triisobutylaluminium (2 5ml of I M solution in toluene) The solution was degassed under reduced pressure and back-filled with an atmosphere of ethylene During the run time of 60 min the solution was left open to a supply of ethylene at one atmosphere and stirred vigorously The polymerisation was terminated by the addition of dilute HC1 (ca 40ml) and the stirred for 30 min to dissolve the alkylaluminium residues Solid polyethylene was filtered from the reaction, washed with acidified methanol and dried under reduced pressure at 40°C overnight Yield of polyethylene 8 94g

Claims: Claims: 1 A catalyst composition suitable for use in the polymerisation of olefins said composition comprising (A) a neutral disci ete metal complex having the genei l formula (L) p MY n X m Z q where L represents a Iigand which remains bound to M under olefin polymerisation conditions, M is a Group IIIA element oi , Group IIIB, IVB, VB, VIB or VIII transition metal (CAS version of the Periodic Table, Cotton & Wilkinson 5 11 ' Ed ), Y is a chelating Iigand comprising at least one atom fiom O, S, N and P bound directly to M, X is the same as Y or is chosen from the gioup compi ising hydride, hydrocarbyl, substituted hydiocarbyl, ha de, perchlorate, substituted sulphonate, trifluoromethane sulphonate, methane sulphonate, fluorosulphonate, aryl sulphonate, bιs(trifluoromethylsulfonyl)methyl, bιs(tπfluoromethylsulfony])benzyl, bis(trifluoromethylsulfonyl)amide, alkoxide, aryloxide, tetraalkylborate, tetraarylborate, tetraphenylborate, substituted tetraphenylborate, tetrakιs(pentafluorophenyl)borate, tetrakιs[bιs(3,5-dιtιιtluoιomethyl)phenyl]borate, tetrafluoroborate, hexafluorophosphate or pentafluoiotelluiate, Z is a neutral Lewis base, n > or = 1 p > or = 1 m > or = 0 and q -> or = 0 , provided that n, m, p and q are integei s or zero which satisfy the valency of the metal and (B) one or more Lewis acids 2 A catalyst composition according to claim 1 wherein the Iigand Y comprises at least one 0 atom bound directly to M 3 A catalyst composition according to either of the preceding claims wherein the Iigand Y is chosen from β-diketonate, β-ketoester or β-ketoaldehyde 4 A catalyst composition according to claim 3 wherein the Iigand Y is acetylacetonate or substituted acetylacetonate 5. A catalyst composition according to any of the preceding claims wherein the X Iigand is hydrocarbyl, halide or trifluoromethane sulphonate 6 A catalyst composition according to any of the pi eceding claims which the Lewis acid is an alkyl or aryl aluminium compound or an alky or aryl boron compound 7 A catalyst composition according to claim 6 wherein the Lewis acid is triisobutylaluminium or tπs(pentafluoro phenyl) boron 8 A catalyst composition accoiding to claim 1 wherein the neutral discrete metal complex has the formula (L)p MY n X m Z q where L represents an unsubstituted oi substituted cyclopentadienyl Iigand, M is a Group 1VB, VB, VIB or V1I1 transition metal (CAS vei sion of the Periodic Table, Cotton & Wilkinson 5 ,h Ed ), Y is a chelating Iigand comprising at least one atom from O, S, N and P bound directly to M, X is the same as Y or is chosen from the group comprising hydnde. hydrocarbyl, substituted hydrocai byl, halide, perchlorate, substituted sulphonate, trifluoromethane sulphonate, methane sulphonate, fluorosulphonate, aryl sulphonate, bis(trifluoι ometlιylsulfonyl)methyl, bιs(tι ιfluoι omethylsulfonvl)benzyl, bis(trifluoromethylsulfonyl)amιde, alkoxide, aryloxide, tetraarylborate, tetraphenylborate, substituted tetraphenylborate, l)boι ate, tetrakis[bis(3,5-dιtrifluoromethyl)phenyl]boιate, teti ailuoioborate, hexafluorophosphate, pentafluorotellurate, Z is a neutral Lewis base, n > or = 1 p > or = 1 m > or = 0, and q > or = 0 provided that n, m, p and q are integers or zero which satisfy the valency of the metal 9 A catalyst composition according to claim 8 wherein M is a Group IVB metal, p is 2 and n is 1 or 2 10 A catalyst composition according to claim 8 wherein M is zirconium 1 1 A catalyst composition according to claim 8 wherein the hgand Y is chosen from β-diketonate, β-ketoestei or β-ketoaldehyde 12 A catalyst composition according to claim 1 1 wherein the gand Y is acetylacetonate or substituted acetylacetonate 13 A catalyst composition according to claim I wherein the neutral discrete metal complex has the fot mula Z / / Cp* - M / \ wherein Cp* is a single η5-cyclopentadιenyl or η5-substιtuted c clopentadienyl group optionally covalently bonded to M through Z-P and corresponding to the formula R wherein R each occurrence is hydrogen or a moiety selected from halogen, alkyl, aryl, haloalkyl, alkoxy, aryloxy, silyl groups, and combinations thereof of up to 20 non-hydrogen atoms, or two or more R groups together form a fused ring system, M is zirconium, titanium or hafnium bound in an η5 bonding mode to the cyclopentadienyl or substituted cyclopentadienyl group and is in a valency state of +3 or +4 Z is a divalent moiety comprising oxygen, boron, or a member of Group 1VA of the Periodic Table of the Elements (CAS Version of the Periodic Table, Cotton & Wilkinson 5 th Ed ), P is a linking group covalently bonded to the metal comprising nitrogen, phosphorus, oxygen or sulfur, or optionally Z and P together form a fused ring system, and X, Y, n and m are as defined above such that n and in satisfy the valency of M 14 A catalyst composition according to claim 1 wherein M is titanium, P is nitrogen and Z is silicon 15 A catalyst composition according to any of the preceeding claims wherein the ratio of the Lewis acid to metal complex is 0 2 10,000 16 A catalyst composition according to any of the preceding claims wherein the discrete metal complex is supported 17 A catalyst composition according to claim 16 wherein the support is silica 18 A process for the polymerisation of ethylene or copolymei isation of ethylene and alpha-olefin comprising contacting the ethylene and alpha-olefins in the presence of a catalyst composition according to any of the preceding claims 19 Discrete metal complexes having the formula (L) 2 M Y X Z — P / / L M X Y wherein L represents an unsubstituted or substituted cyclopentadienyl Iigand, Z is a divalent moiety comprising oxygen, boron, or a member of Group IVA of the Periodic Table of the Elements (CAS Version of the Periodic Table, Cotton & Wilkinson 5 11 ' Ed) P is a linking group covalently bonded to the metal comprising nitrogen, phosphorus, oxygen or sulphur, optionally Z and P form a fused ring system, and M is Zr, Ti or Hf X is SO 3 CF 3 or hydrocarbyl Y is RCOCHCOR wherein R may be the same or different and is hydrocarbyl or substituted hydrocarbyl. 20 A method for preparing complexes of formula Cp 2 MXY by reacting a complex of formula Cp 2 M (hydrocarbyl) X with a dione of formula RCOCH 2 COR in a suitable solvent, wherein M - Zr, Ti, Hf Y = RCOCHCOR X = SOiCF,, and R = hydrocarbyl 21 A method for preparing complexes of formula Cp 2 M (hydrocai byl) Y by treatment of a solution of a complex of formula Cp 2 M (hydrocarbyl) 2 dropwise with a dione of formula RCOCH 2 COR, wherein M = Zr, Ti, Hf Y = RCOCHCOR, and R = hydrocarbyl 22 Discrete metal complexes of formula (l,3-(CH ) 2 C 5 H;) 2 Zr(CRCOCHCOCH SO;CF, ( 1 ,3-(CH 3 ) 2 C 5 H,) 2 Zr(CF,COCHCOCF SO,CF, ( l,3-(CH 3 ) 2 C s H 2Zr(CH,COCHCOOCH 2 CH SO,CF, (CH 2 Si((CH 3 ) 4 C 5 )(NC(CH 3)Ti(CF COCHCOCF Sθ3CF : , ( l,3-(CH 3 ) 2 C 5 H 2Zr((CH *CCOCHCOC(CH SO,CF, (CsH 5 ) 2 Zr(CH.,COCHCOCH CH,

Inventors: DORER BIRGIT ANGELIKA, LITTLE IAN RAYMOND, SHARP CHRISTOPHER, STICHBURY JOANNE CLARE, DORER, BIRGIT, ANGELIKA, LITTLE, IAN, RAYMOND, SHARP, CHRISTOPHER, STICHBURY, JOANNE, CLARE
Applicants: BP CHEM INT LTD, DORER BIRGIT ANGELIKA, LITTLE IAN RAYMOND, SHARP CHRISTOPHER, STICHBURY JOANNE CLARE, BP CHEMICALS LIMITED, DORER, BIRGIT, ANGELIKA, LITTLE, IAN, RAYMOND, SHARP, CHRISTOPHER, STICHBURY, JOANNE, CLARE
Application year: 1997
Main classification: C08F4
IPC codes: C07F7, C07F17, C08F4, C08F10