Catalyst compositions and process for preparing polyolefins

Catalyst compositions comprising metallocene complexes having polymerisable may be used for the preparation of polyolefins. The catalyst compositions may be in the form of polymers comprising the metallocene complex and may be suitably supported on inorganic supports. Polymers having a broad range of density and melt indices as well as low hexane extractables and excellent powder morphology and flowability may be obtained by use of the catalyst compositions. Preferred metallocene complexes are zirconium complexes in which the polymerisable group is vinyl.

The present invention relates to novel catalyst compositions comprising 
metallocene complexes and their use in the polymerisation of olefins. 
BACKGROUND OF THE INVENTION 
Metallocene complexes of Group IVA metals such as (cyclopentadienyl).sub.2 
ZrCl.sub.2 are known as homogeneous polyolefin catalysts in the presence 
of a suitable co-catalyst. Such catalyst systems have proven to be highly 
active towards ethylene and alpha olefins forming narrow molecular weight 
distributions of polyolefins. 
It would be highly desirable to provide catalysts which may be used, 
particularly in the gas phase, to prepare polymers which show good 
performance and processability. 
We have now discovered that catalyst compositions comprising metallocene 
complexes having a polymerisable group may advantageously be used in the 
polymerisation of olefins. 
SUMMARY OF THE INVENTION 
Accordingly, the present invention provides a catalyst composition 
comprising at least one metallocene complex of general formula I or II 
##STR1## 
wherein R is a univalent or divalent 1-20C hydrocarbyl, or a 1-20C 
hydrocarbyl containing substituent oxygen, silicon, phosphorus, nitrogen 
or boron atoms with the proviso that at least one R group contains a 
polymerisable group and preferably contains at least three carbon atoms, 
and when there are two R groups present they may be the same or different, 
and when R is divalent it is directly attached to M, and replaces a Y 
ligand, wherein 
X is an organic group containing a cyclopentadienyl nucleus, 
M is a Group IVA metal, 
Y is a univalent anionic ligand, and for formula I, 
n is an integer of 1 to 10 
x is either 1 or 2, and 
when x=1, p=0-3, that is, when all R are univalent, p=3; when one R is 
divalent, p=2, when two Rs are divalent, p=1 and when three Rs are 
divalent, p=0, 
when x=2, p=0-2, that is, when all R are univalent, p=2; when one R is 
divalent, p=1 and when two Rs are divalent, p=0, and for formula II, 
n, m and 1 are integers or 0 such that n+m+1.gtoreq.1, p=0-2, that is, when 
all R are univalent, p=2; when one R is divalent, p=1 and when two Rs are 
divalent, p=0, and 
Z is a C.sub.1 to C.sub.4 alkylene radical or a dialkyl germanium or 
silicon or an alkyl phosphine or amine radical or bis-dialkylsilyl or 
bis-dialkylgermanyl containing hydrocarbyl groups having 1 to 4 carbon 
atoms bridging the cyclopentadienyl nuclei. 
DETAILED DESCRIPTION OF THE INVENTION AND THE PREFERRED EMBODIMENTS 
The metallocene complex of the present invention is a Group IVA metallocene 
complex of general formula I or II wherein M is suitably hafnium, 
zirconium or titanium. Preferably, M is zirconium. 
In the metallocene complex of general formula I or II, X comprises a 
cyclopentadienyl nucleus. Suitably X represents a single ring 
cyclopentadienyl nucleus or a fused ring one such as indenyl or 
tetrahydroindenyl or fluorenyl nucleus. Preferably X is a single ring 
cyclopentadienyl nucleus. 
In the metallocene complex of general formula I or II when there are two or 
more R groups present these may be the same or may be different. At least 
one of R contains the polymerisable group, especially an olefinic group. 
The R groups of the metallocene complex are independently organic 
hydrocarbyl groups, at least one of the R groups having a polymerisable 
group. For the purposes of the present invention, a polymerisable group 
may be defined as a group which can be incorporated into a growing polymer 
chain. The preferred polymerisable group of which R consists or comprises 
is an olefinic group. Preferably, the olefinic group consists of or 
comprises a vinyl group. 
R may independently be an alkenyl group of suitably 2 to 20, preferably 3-8 
carbon atoms. The alkenyl may suitably be linear or branched, for example, 
an alkenyl group such as but-3-enyl or oct-7-enyl; or an alkenyl aryl, 
alkenyl cycloalkyl or alkenyl aralkyl group, each having 8 to 20 carbon 
atoms, especially p-vinyl phenyl or p-vinyl benzyl. 
Additionally, one of the R groups may be a silyl group such as trimethyl 
silyl, triethyl silyl, ethyldimethyl silyl, methyldiethyl silyl, 
phenyldimethyl silyl, methyldiphenyl silyl or triphenyl silyl. 
R may also represent an organic hydrocarbyl group such as an alkyl group of 
1 to 10 carbon atoms such as methyl, ethyl, propyl hydrocarbyl groups or a 
cycloalkyl group containing 5 to 7 carbon atoms, for example, cyclohexyl 
or an aromatic or aralkyl group of 6 to 20 or 7 to 20 carbon atoms 
respectively, for example, phenyl or benzyl. 
m and/or n is at least 1 and not greater than 10, e.g. 1-5, the maximum 
value depending on the number of possible substituent positions available 
in the X nucleus. Where for example X is cyclopentadienyl, the maximum for 
n is 5 whilst the maximum of n is 7 for the indenyl nucleus. 
Y is a univalent anionic ligand. Suitably the ligand is selected from 
hydride, halides, for example, chloride and bromide, substituted 
hydrocarbyls, unsubstituted hydrocarbyls, alkoxides, amides or phosphides, 
for example, a dialkylamide or a dialkyl or alkyl aryl phosphide group 
with 1 to 10 carbon atoms in each alkoxide or alkyl group and 6 to 20 
carbons in the aryl group. 
The preferred metallocene complex of general formula I is when: 
M is zirconium 
R is C.sub.3 to C.sub.10 hydrocarbyl having a vinyl group 
X is a cyclopentadienyl group 
Y is chloride, 
n is 1 or 5 
x is 2, and 
p is 2. 
The preferred metallocene complex of general formula II is when: 
M is zirconium 
R is C.sub.3 to C.sub.10 hydrocarbyl with a vinyl group 
X is an indenyl group 
Y is chloride 
n=m=1 
l=0, and 
Z is a C.sub.1 to C.sub.4 alkylene or a bis dimethylsilyl containing 
C.sub.1 to C.sub.4 hydrocarbyl group.

DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS 
Metallocene complexes of general formula I, where x=2, and general formula 
II may suitably be prepared by reacting a suitable group IVA metal salt of 
the general formula MYYCl.sub.2 with a compound with a polymerisable group 
containing a cyclopentadienyl anion of the general formula (R).sub.n X!M' 
or R.sub.n X--ZR.sub.1 --XR.sub.m !M'.sub.2. Suitably the M' is an 
alkaline metal. It is preferred that the Group IV metal salt is a tetra 
halide salt, most preferably a tetrachloride salt. It is preferred that 
the preparation of the metallocene complex is carried out in the presence 
of an anhydrous organic solvent such as an aliphatic ether such as diethyl 
ether or an aromatic hydrocarbon such as toluene or a cyclic ether such as 
tetrahydrofuran and under an inert atmosphere. The preferred conditions 
are in the presence of dry tetrahydrofuran and under dry nitrogen. 
If a metallocene complex is to be prepared in which the R groups are 
different then for formula (I) where x=2 two different (R).sub.n X!M' 
compounds are used and for formula II, the appropriate mixed compound is 
used. 
The salt of general formula (R).sub.n X!M' (III) may be prepared by any 
suitable method from the corresponding compound of formula (R).sub.n XH 
(IV) by reaction with a suitable metal. Suitably, the metal is an alkaline 
metal selected from lithium, sodium or potassium. The metal may also be an 
organo hydrocarbyl alkali metal compound such as an alkyl or phenyl 
sodium, lithium or potassium compound. Preferably, it is a lithium 
compound. 
The compound (R).sub.n XH may itself be formed by reaction of a compound of 
general formula XM" (V) where M" is an alkali metal. Suitably XM" is 
sodium cyclopentadiene. XM" may be reacted with a compound R--R" where R 
is as defined above and R" is a suitable leaving group. Alternatively, XM" 
and X'M" may be reacted with Z(R).sub.1 R".sub.2. R" may suitably be a 
nucleophilic leaving group. Preferably, R" is a halide selected from 
chloride, bromide or iodide, an ester group, especially a sulphonate ester 
such as alkane sulphonate or aryl sulphonate. Suitably, the aforementioned 
reactions are carried out in the presence of an anhydrous organic solvent 
and under an inert atmosphere. 
Where it is desired to prepare the metallocene complex of general formula I 
wherein x is 1, the complex may suitably be prepared using procedures well 
known in the field. For example, the cyclopentadiene compound X(R).sub.n H 
could be reacted with a metallating agent where the metal (M") is a Group 
I alkali metal to provide X(R).sub.n M". Metallating agents include n-BuLi 
or MeLi. Suitably X(R).sub.n M" is then reacted with trimethylsilyl 
chloride in an appropriate solvent to provide (Me3Si)X(R)n. Further 
reaction with a Group IV metal halide will suitably provide a metallocene 
complex of general formula MX(R).sub.n !Y.sub.3. This synthesis is 
particularly preferred for the preparation of the titanium metallocene, 
although variations of the synthesis can be used to prepare analogous 
zirconium and hafnium complexes. In another example, if X(R).sub.n 
contains one or more functional groups with a protonated heteroatom, 
additional equivalents of the metallating reagent will deprotonate both 
the cyclopentadiene nucleus and one or more of the heteroatoms. Reaction 
of the metallated polyanion with a Group IV metal halide will suitably 
provide a metallocene complex of general formula MX(R).sub.n !y.sub.t, 
where Y is halide and t=0-2. In this case, (3--t) R groups will bridge the 
cylopentadienyl nucleus and the metal atom by means of a bond between the 
metal atom and a deprotonated heteroatom. 
If desired the complexes of formula I or II wherein Y is halide may be 
converted into the complexes of formula I or II wherein Y is the other 
specified groups by reaction of the halide with an appropriate nucleophile 
e.g. alkoxide. 
One or more metallocene complexes of general formula I or II may suitably 
be used as a catalyst in various reactions. The complexes may suitably be 
supported on an inorganic support to give a supported catalyst composition 
which forms one aspect of the present invention. Any suitable inorganic 
support may be used, for example, inorganic oxides such as silica, 
alumina, silica-alumina mixtures, thoria, zirconia, magnesia, titania and 
mixtures thereof. Equally suitably inorganic halides may be used. Suitable 
halides include group IIA halides, e.g. magnesium chloride. The complex of 
formula I or II preferably comprises 0.01-50% by weight of said supported 
catalyst composition. 
One or more metallocene complexes may suitably be impregnated onto the 
support material under anhydrous conditions and under an inert atmosphere. 
The solvent may then be evaporated under reduced pressure. The impregnated 
support may then be heated to remove any remaining solvent. 
The metallocene complex of general formula I or II may be used in the 
presence of a suitable co-catalyst. Suitably the co-catalyst is an 
organometallic compound having a metal of Group IA, IIA, IIB or IIIB of 
the periodic table. Preferably, the metals are selected from the group 
including lithium, aluminium, magnesium, zinc and boron. Such co-catalysts 
are known for their use in polymerisation reactions, especially the 
polymerisation of olefins, and include organo aluminium compounds such as 
trialkyl, alkyl hydrido, alkyl halo and alkyl alkoxy aluminium compounds. 
Suitably each alkyl or alkoxy group contains 1 to 16 carbons. Examples of 
such compounds include trimethyl aluminium, triethyl aluminium, diethyl 
aluminium hydride, triisobutyl aluminium, tridecyl aluminium, tridodecyl 
aluminium, diethyl aluminium methoxide, diethyl aluminium ethoxide, 
diethyl aluminium phenoxide, diethyl aluminium chloride, ethyl aluminium 
dichloride, methyl diethoxy aluminium and methyl aluminoxane. The 
preferred compounds are alkyl aluminoxanes, the alkyl group having 1 to 10 
carbon atoms, especially methyl aluminoxane. Where Y in the general 
formula I or II is independently hydrogen or hydrocarbyl, suitable 
co-catalysts also include Bronsted or Lewis acids. 
The co-catalyst may be mixed with the metallocene, optionally on an 
inorganic support. Alternatively, the co-catalyst may be added to the 
polymerisation medium along with the metallocene complex. Suitably, the 
amount of co-catalyst mixed with metallocene complex may be such as to 
provide an atom ratio of M from the metallocene to the metal in the 
co-catalyst of 1-10,000: 10,000-1 for aluminoxanes and 1-100: 100-1 
otherwise. 
One or more metallocene complexes of general formula I or II, in the 
presence of a co-catalyst, may be used to produce polymers containing one 
or more metals M. The metallocene containing polymer usually contains a 
high group IVA metal content and is usually a low yield polyolefin, 
comprising one or more metallocene complexes of general formula I and/or 
II with one or more olefins. 
Thus according to another aspect of the present invention there is provided 
a catalyst composition suitable for use in the polymerisation of olefins 
comprising a polymer containing a metallocene complex of general formula I 
or II as described above, preferably as a copolymer with at least one 
alpha-olefin and/or ethylene. 
The metallocene containing polymer may suitably be prepared by heating one 
or more metallocene complexes of general formula I and/or II, optionally 
supported, usually in the presence of an inert solvent and/or suitable 
co-catalysts as described above and preferably in the presence of one or 
more alpha-olefins or ethylene, so that the metallocene complex is 
co-polymerised. Suitably the alpha-olefin may be a C3 to C10 olefin. 
The conditions of formation of the metallocene containing polymer are 
substantially similar to those for the polymerisation of olefins described 
hereafter, but with a lower degree of polymerisation, e.g. for a shorter 
time. 
The metallocene containing polymer may suitably be impregnated onto the 
support material under anhydrous conditions and under an inert atmosphere. 
The impregnation can be conducted using an inert solvent, in which case 
the solvent may then be evaporated under reduced pressure. The impregnated 
support may then be heated to remove any remaining solvent. Preferably, 
the metallocene containing polymer is dissolved in the inert solvent. 
Suitable inert solvents include aromatic hydrocarbons, such as toluene. 
Any suitable inorganic support may be used for example, inorganic oxides 
such as silica, alumina. Equally suitable inorganic halides may be used. 
Suitable halides include Group IIA halides e.g. magnesium chloride. 
The catalyst composition comprising the metallocene containing polymer may 
be used in the presence of a suitable co-catalyst, as described above. The 
co-catalyst may be mixed with the metallocene containing polymer 
optionally as an inorganic support. Alternatively the co-catalyst may be 
added to the polymerisation medium along with the metallocene containing 
polymer. 
It is a particular advantage of this aspect of the present invention that 
an active catalyst composition comprising a metallocene containing polymer 
may be supported on an inorganic oxide or metal halide support without 
using cocatalysts such as aluminoxanes as the means of support. 
Aluminoxanes are expensive and difficult to handle and it is desirable to 
minimise their use. Conventionally, they are used as both a means of 
binding metallocenes to inorganic supports and as cocatalysts. The current 
invention obviates the need for aluminoxanes as a means of binding. This 
allows their use as cocatalysts only or not at all by selecting 
alternative cocatalysts, e.g. Bronsted or Lewis acids. 
A further advantage of this aspect of the current invention is that it 
provides a support method which prevents desorption of metallocene 
complexes from a supported catalyst under certain polymerisation process 
conditions, e.g. slurry. Conventional metallocene support methods where 
the metallocene complex is simply adsorbed onto the support surface, with 
or without the use of cocatalysts such as aluminoxanes, may undergo some 
metallocene complex desorption under polymerisation process conditions. 
The resulting metallocene containing polymer may be reacted with an olefin 
to produce a polyolefin as described below. The polymer may be supported 
on an inorganic support as described above and may suitably be mixed with 
a co-catalyst. 
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 C8 alpha-olefin. The 
process comprises contacting the monomer or monomers, optionally in the 
presence of hydrogen, with a catalyst composition comprising at least one 
metallocene complex of formula I or II in an olefin polymerisation 
catalyst composition according to the above aspects of the present 
invention at a temperature and pressure sufficient to initiate the 
polymerisation reaction. The catalyst composition may preferably be in the 
form of a supported metallocene containing polymer of the metallocene 
complex as described above. 
Suitably the alpha olefin may be propylene, butene-1, hexene-1, 4-methyl 
pentene-1 and octene-1 and may be present with the ethylene in amounts of 
0.001-80% by weight (of the total monomers). The polymers or copolymers of 
ethylene thus obtained can have densities, in the case of homopolymers of 
about 950 to 960 or 965 kg/m.sup.3 or in the case of copolymers, as low as 
915 kg/m3. The C3 to C8 alpha-olefin content in the copolymers of ethylene 
can be about from 0.01% to 10% by weight or more. 
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 are well known and 
described in, for example, Encyclopaedia of Polymer Science and 
Engineering published by John Wiley and Sons, 1987, Volume 7, pages 480 to 
488 and 1988, 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 polymerisation catalysts. 
The polymerisation may optionally be carried out in the presence of 
hydrogen. Hydrogen or other suitable chain transfer agents may be employed 
in the polymerisation to control the molecular weight of the produced 
polyolefin. The amount of hydrogen may be such that the percentage of the 
partial pressure of hydrogen to that of olefin(s) is from 0.01-200%, 
preferably from 0.05-10%. 
Typically, the temperature is from 30.degree. to 110.degree. C. for the 
slurry or "particle form" process or for the gas phase process. For the 
solution process the temperature is typically from 100.degree. to 
250.degree. C. The pressure used can be selected from a relatively wide 
range of suitable pressures, e.g., from subatmospheric to about 350 MPa. 
Suitably, the pressure is from atmospheric to about 6.9 MPa, or may be 
from 0.05-10, especially 0.14 to 5.5 MPa. In the slurry or particle form 
process the process is suitably performed with a liquid inert diluent such 
as a saturated aliphatic hydrocarbon. Suitably the hydrocarbon is a C4 to 
C10 hydrocarbon, e.g. isobutane or an aromatic hydrocarbon liquid such as 
benzene, toluene or xylene. The polymer is recovered directly from the gas 
phase process or by filtration or evaporation from the slurry process or 
evaporation from the solution process. 
Polymers having a broad range of density and melt indices as well as 
showing lower hexane extractables and excellent powder morphology and 
flowability may be obtained by using catalyst compositions according to 
the present invention. Film grade materials may be obtained having 
improved performance, and which show a very good balance between 
mechanical properties and processability. 
Copolymers of ethylene with C3 to C8 alpha-olefins may be prepared in the 
form of porous powders having a melt index in the range 1-3 g/10. min, 
density in the range 0.910-0.925 g/cm.sup.3, a mean particle size in the 
range 400-1200 .mu.m, a bulk density in the range 0.37-0.50 g/cm.sup.3 and 
a percentage of fines 125 .mu.m of 0-1%. 
Preferred copolymers are those obtained from C4 to C6 alpha-olefins having 
a melt index in the range 1.5-3 g/10 mm and density in the range 
0.914-0.920 g/cm.sup.3. 
Such copolymers are preferably prepared by copolymerisation in the gas 
phase. 
The copolymers may be used to prepare both blown and cast films. For 
example blown films may be obtained of 25 .mu.m thickness having an impact 
in the range 250 g (Method A)--700 g (Method B), secant modulus in the 
range 130-250 MPa, shear viscosity in the range 300-800 Pa.s. and hexane 
extractables on film of &lt;2%. (by FDA 177.1520). 
For catalyst compositions containing one metallocene complex, polymers of 
unimodal molecular weight distribution may be obtained. In the case where 
two or more metallocene complexes are present the resulting polymers may 
have bimodal or multimodal molecular weight distributions and, in the case 
of copolymerisation, have non-uniform branch distributions within the 
molecular weight distribution. 
The catalyst compositions of the present invention which include 
metallocene containing polymer may also be used to prepare polyolefins 
having much lower melt indexes compared to those prepared using other 
metallocene catalysts. 
Melt Index Measurement 
The Melt Index (MI) of the polymers produced was determined according to 
ASTM D1238 Condition E, 2.16 kg at 190.degree. C. while the High Load Melt 
Index (HLMI) was according to ASTM D1238 condition F, 21.6 kg at 
190.degree. C. 
Method for Measuring the Molecular Weight Distribution 
The molecular weight distribution of a (co)polymer is calculated according 
to the ratio of the weight-average molecular weight, Mw, to the 
number-average molecular weight distribution curve obtained by means of a 
"WATERS" (trademark) model "150 C" gel permeation chromatograph (High 
Temperature Size Exclusion Chromatograph), the operating conditions being 
the following: 
solvent: 1,2,4-trichlorobenzene; 
solvent flow rate: 1.0 ml/minute; 
three "SHODEX" (trademark) model "AT 80 MS" columns of 25 cm length are 
employed; 
temperature: 145.degree. C.; 
sample concentration: 0.1% by weight; 
injection volume: 500 microliters; 
Universal standardisation using monodisperse polystyrene fractions. 
The present invention will now be further illustrated with reference to the 
following examples: 
All of the reactions and purifications detailed below involving 
organometallic species were carried out under a dry nitrogen atmosphere 
using standard vacuum-line techniques. Tetrahydrofuran and diethyl ether 
were dried over sodium benzophenone ketyl and distilled. Toluene was dried 
over sodium-potassium and distilled. Dichloromethane was dried over 4.ANG. 
molecular sieves. All other reagents were used as received. 
Impact Measurement 
The impact measurement of polymer films was determined according to ASTM 
D1709-85. The test method determines the energy required to cause a 
polyethylene film to fail under specified conditions of impact of a free 
falling dart. The energy is expressed in terms of the weight. Two methods 
were used. In Method A the height used was 66 cms for films with impact 
resistances requiring masses &lt;300 g and in Method B the height was 152.4 
cm for films requiring masses &gt;300 g. 
Perforation Energy 
The energy required to cause polyethylene film to perforate under specified 
conditions was determined according to ASTM D781 using an Adamel-Lhomargy 
puncture tester. 
The present invention will be further illustrated with reference to the 
following examples. 
EXAMPLE 1 
Preparation of Bis(3-butenylcyclopentadienyl)zirconium Dichloride 
Step (a) Preparation of 3-buten-1-tosylate 
To a solution of 100 g (525 mmol) p-toluenesulphonyl chloride in 200 ml of 
dry pyridine cooled to 0.degree. C. was added 21.1 g (29.3 mmol) 
3-buten-1-ol. The reaction solution was thoroughly mixed and allowed to 
stand in a refrigerator at -5.degree. C. overnight. The reaction mixture 
was then poured with stirring into 200 g of ice/water. The oily tosylate 
product was extracted from the aqueous mixture with 3.times.300 ml 
aliquots of ether. The combined ethereal fractions were washed twice with 
300 ml of cold aqueous hydrochloric acid (conc HCl:water 1:1 w/w) to 
remove pyridine and then with 300 ml water, dried over potassium carbonate 
and sodium sulphate and decolourised with activated carbon. The suspension 
was filtered and the ether evaporated from the filtrate under reduced 
pressure to leave a pale yellow oil. The oil was then washed with cold 
pentane to remove impurities and induce crystallisation. 51.0 g of 
spectroscopically pure product (.sup.1 H NMR) as a microcrystalline white 
solid were isolated (225 mmol, 76.7%). 
Step (b) Preparation of 3-butenylcyclopentadiene 
To a solution of 25.0 g (110 mmol) 3-buten-1-tosylate prepared according to 
step (a) above in 200 ml THF cooled to 0.degree. C. was added 68.9 ml of 
2.0M (138 mmol) sodium cyclopentadienylide in THF. The reaction mixture 
was allowed to warm to room temperature and was stirred for 16 h. 100 ml 
concentrated aqueous saline solution was added and the product extracted 
with ether (3.times.75 ml). The combined organic fractions were dried over 
magnesium sulphate for 2 hours, filtered and the solvents removed under 
reduced pressure using a rotary evaporator to yield a dark brown oil. The 
crude product was distilled under reduced pressure (b.p. 
50.degree.-51.degree. C. @15 mm Hg) to give 5.71 g of a colourless oil 
(47.6 mmol, 43.3%). 
Step (c) Preparation of Bis(3-butenylcyclopentadienyl) zirconium Dichloride 
19 ml of 2.5M (47.5 mmol) butyllithium in mixed C.sub.6 alkane solvent was 
slowly added to 5.7 g (47.5 mmol) 3-butenylcyclopentadiene prepared 
according to step (b) above in 50 ml THF cooled to 0.degree. C. and 
stirred for 1 hour. The lithium 3-butenyl cyclopentadienylide solution 
produced was added to 4.43 g (19.0 mmol) zirconium tetrachloride in 50 ml 
THF cooled to 0.degree. C. and stirred for 65 hours. The volatiles were 
removed under vacuum and the residue extracted with ether and filtered. 
The product was precipitated as a microcrystalline white solid upon slow 
cooling of the solution to -50.degree. C. Recrystallisation from cold 
ether (-12.degree. C.) yielded 1.54 g of spectroscopically pure product 
(.sup.1 H NMR) as colourless needles (3.85 mmol, 20.2%). 
EXAMPLE 2 
Preparation of Bis(3-propenylcyclopentadienyl)zirconium Dichloride 
Step (a) Preparation of 3-Propenylcyclopentadiene 
To a rapidly stirred solution of allylbromide (42.73 g; 0.35 mol) dissolved 
in dry THF (200 ml) at 0.degree. C. was added a solution of sodium 
cyclopentadiene (220 ml, 2.0M; 0.44 mol) in THF. The reaction was stirred 
for 2 hrs during which time it was allowed to warm to room temperature. 
Iced water (1500 ml) was added and the organic product extracted with 
diethyl ether (3.times.400 ml). The combined organic fractions were dried 
over magnesium sulphate overnight, filtered and the solvents removed under 
reduced pressure using a rotary evaporator to yield a pale brown oil. The 
crude product was distilled under reduced pressure (b.p. 
35.degree.-45.degree. C. @17 mm Hg) to give 11.17 g of a colourless oil 
(0.105 mol, 33.3%). 
Step (b) Preparation of bis (3-propenylcyclopentadienyl)zirconium 
Dichloride 
Methyllithium solution (75.25 ml, 1.4M; 0.105 mol) in diethyl ether was 
slowly added to a rapidly stirred solution of propenylcyclopentadiene 
(11.17 g, 0.105 mol) in dry diethyl ether at 0.degree. C. The reaction was 
warmed to room temperature and stirring continued until gas evolution had 
ceased. The precipitated lithium propenylcyclopentadienylide was isolated 
by filtration, washed with diethyl ether (2.times.100 ml) and pumped to 
dryness to give 10.65 g (0.095 mol) of fine white powder. To a rapidly 
stirred THF solution (100 ml) of the lithium propenylcyclopentadienylide 
at 0.degree. C. was added zirconium tetrachloride (11.09 g, 47.5 mmol) 
dissolved in dry THF (100 ml). The reaction mixture was allowed to warm to 
room temperature and was stirred for 16 hrs. The volatiles were removed 
under vacuum and the residue extracted with diethyl ether (4.times.100 ml) 
and filtered. The product was obtained as a microcrystalline white solid 
upon slow cooling of the solution to -78.degree. C. Recrystallisation from 
cold ether yielded 13.33 g of spectroscopically pure product (.sup.1 H 
NMR) as colourless needles (35.8 mmol, 75.4%). 
EXAMPLE 3 
Preparation of Supported Catalyst 
15 mol of MAO (10% solution in toluene, WITCO) and 100 mmol 
bis(3-propenylcyclopentadienyl)zirconium dichloride (prepared as in 
Example 2) in 1.5 liters toluene were maintained at room temperature with 
stirring for 15 min. 2 kg of silica (GRACE SD 3217.50 dried at 800.degree. 
C. for 5 hrs) was added to the mixture to form a suspension. The resultant 
mixture was stirred for 1 hr at room temperature, the suspension 
transferred to a drier and the solvent removed at 120.degree. C. to 
provide a free-flowing spherical powder. 
EXAMPLES 4-5 
Preparation of Supported Catalysts 
The procedure in Example 3 was repeated using 
bis(3-butenylcyclopentadienyl)zirconium dichloride (prepared as in Example 
1) and Crosfield ES70 silica in Example 4 and Grace SD 3217.50 silica in 
Example 5. 
EXAMPLE 6 
Ethylene Homopolymerisation 
400 g sodium chloride were introduced under nitrogen into a 2.5 liter 
stainless steel autoclave equipped with a stirrer. The temperature was 
increased to 80.degree. C. and the autoclave charged with supported 
catalyst obtained in Example 3 (0.02 mmol Zr). Ethylene pressure was 
increased to 0.8 MPa. After 2 hrs the sodium chloride was removed by 
washing with water to yield 245 g polyethylene of very good morphology 
having a melt index of 0.8 g/10 min measured at 190.degree. C. under a 
load of 2.16 kg (ASTM-D-1238-condition E), bulk density 0.42 g/cm.sup.3, 
an average particle diameter measured by laser diffraction of 545 .mu.m 
and 0.6% of fine powder less than 125 .mu.m. 
EXAMPLE 7 
Ethylene/1-butene Copolymerisation 
The procedure of Example 6 was repeated using supported catalyst (0.025 
mmol Zr), an ethylene pressure of 0.9 MPa and the introduction of 1-butene 
into the autoclave to produce a polymer of density of 0.920 g/cm.sup.3 non 
annealed. After 70 min. the sodium chloride was removed by washing with 
water to yield 575 g of copolymer of very good morphology containing 4.8 
wt % of butene, having a melt index of 3 g/10 min. measured at 190.degree. 
C. under a load of 2.16 kg, 0.6% Kumagawa C.sub.6 -extractables and bulk 
density 0.43 g/cm.sup.3. 
EXAMPLE 8 
Ethylene/1-butene Copolymerisation 
The procedure in Example 7 was repeated using supported catalyst as 
described in Example 4 (0.1 mmol Zr) and an ethylene pressure of 0.25 MPa. 
1-Butene was introduced to give a polymer of density of 0.916 g/cm.sup.3 
non annealed. After 2 hrs the sodium chloride was removed to yield 530 g 
of copolymer of very good morphology having a melt index of 7.8 g/10 min 
measured at 190.degree. C. under a load of 2.16 kg, 2% Kumagawa C.sub.6 
extractables and a bulk density of 0.44 g/cm.sup.3. 
The comonomer was very well distributed in the polymer showing a relative 
dispersity measured by .sup.13 C NMR (Brucker, 200 MH.sub.z) of 103.3 and 
branching dispersity measured by differential scanning calorimetry (after 
storing at 200.degree. C., cooling at a rate of 16.degree. C. per minute 
and heating at a rate of 16.degree. C. per minute) after flow cooling in 
the range 1.3 to 1.5. 
EXAMPLE 9 
Ethylene Homopolymerisation 
The procedure was carried out in a fluidised bed reactor having a diameter 
of 15 cm, height of 1 m and operating with the aid of a fluidisation gas 
propelled at an upward velocity of 25 cm/s. Ethylene pressure was 
maintained at 1 MPa, hydrogen maintained during 2 hrs 35 min. at a ratio 
of PH.sub.2 /PC.sub.2 =0.004 and the temperature maintained at 90.degree. 
C. 1000 g of anhydrous homopolyethylene was introduced as a charge powder 
followed by catalyst of Example 5 (0.18 mmol Zr). 4630 g polyethylene was 
obtained having a melt index of 3.7 g/10 min measured at 190.degree. C. 
under a load of 2.16 kg, density of 0.961 g/cm3 non annealed and a bulk 
density of 0.36 g/cm3. 
EXAMPLE 10 
Ethylene/1-butene Copolymerisation 
The procedure in Example 9 was repeated using an ethylene pressure of 1.15 
MPa while 1-butene was maintained for 3 hrs at a ratio of PC.sub.4 
/PC.sub.2 =0.042 at a temperature of 55.degree. C. Supported catalyst of 
Example 5 (0.07 mmol Zr) was used to yield a copolymer having a melt index 
of 1.2 g/10 min measured at 190.degree. C. under a load of 2.16 kg, a 
density of 0.913 g/cm.sup.3, a bulk density of 0.41 g/cm.sup.3 and 0.6% 
Kumagawa C.sub.6 extractables. 
EXAMPLE 11 
Ethylene/n-hexene Copolymerisation 
Ethylene, n-hexene and nitrogen were fed into a continuous fluidised bed 
reactor of diameter 45 cms maintained at a total pressure of 1.9 MPa. The 
gas composition was maintained constant at PC.sub.6 /PC.sub.2 =0.03 and 
supported catalyst of Example 3 injected into the reactor continuously at 
a rate of 7 g/hr to maintain a constant reaction rate in the reactor. 
Polymer product was continuously removed from the reactor through a valve 
as copolymer of density of 0.916 g/cm.sup.3 non annealed having 1 ppm of 
catalyst residues and 560 Pa.s of shear viscosity at 100 radian/s. 
The reaction conditions were varied to prepare different types of copolymer 
which all exhibit very high impact strength combined with excellent 
processability. The results are given in Table 1. 
EXAMPLE 12 
Comparative 
A mixture of 150 mmol MAO (WITCO) and bis(n-butylcyclopentadienyl)zirconium 
dichloride in 50 ml of toluene were stirred at room temperature under 
nitrogen. 20 g silica (Grace SD 3217.50, dried at 800.degree. C. for 5 hr) 
were added to the mixture to form a suspension and the mixture stirred for 
1 hr at room temperature before raising the temperature to 120.degree. C. 
and the solvent removed to give a free flowing powder. 
EXAMPLE 13 
Comparative 
400 g of sodium chloride were introduced into a 2.5 liter stainless steel 
autoclave equipped with a stirrer. The temperature was increased to 
80.degree. C. and the autoclave charged with the supported catalyst 
obtained in Example 12 (0.1 mmol Zr). Ethylene pressure was increased to 
0.2 MPa and after 5 hrs the sodium chloride removed by washing with water 
to yield polyethylene having a melt index of 7.7 g/10 min measured at 
190.degree. C. under a load of 2.16 kg (ASTM-D-1238 Condition-E), an 
average particle diameter measured by laser diffraction of 376 .mu.m and 
7.5% of fine powder less than 125 .mu.m. 
EXAMPLES 14-16 
Preparation of Metallocene-containing Polymers 
Preparative details for each polymer, and the zirconium content before and 
after toluene washing, are given in Table 2. 
A solution of MAO in toluene was added to the metallocene complex and the 
solution stirred to dissolve the metallocene. The mixture was heated to 
50.degree. C. and ethylene introduced at a measured flow rate. After the 
ethylene flow was stopped the mixture was filtered and the solid polymer 
washed with 5.times.25 ml aliquots of toluene at room temperature. 
Residual solvent was removed under vacuum. 
A sample of each metallocene containing polymer (0.5-1 g) was transferred 
to a round bottom flask, 100 ml toluene added and the mixture stirred 
while the flask was heated to 100.degree. C. for 3 hrs resulting in a 
clear pale yellow solution. The flask was cooled to room temperature 
resulting in reprecipitation of the polymer. The solution was filtered and 
the polymer washed with 5.times.25 ml aliquots of toluene at room 
temperature. Residual solvent was removed under vacuum. 
Due to the high solubility of the free metallocene complex in toluene, the 
zirconium analyses before and after washing indicate that the metallocene 
complex has been incorporated into the polymer. 
EXAMPLE 17 
Preparation of Supported Metallocene-containing Polymer 
750 mmol (Al) MAO (WITCO, 10% in toluene), and 5 mmol of 
bis(3-butenylcyclopentadienyl)zirconium dichloride (prepared as in Example 
1) in 200 ml toluene were added under N.sub.2 to 1-3 liters of toluene at 
80.degree. C. in a stainless steel reactor. Ethylene was introduced into 
the reactor at a uniform rate of 100 g/h for 30 min. and then the reactor 
cooled to 20.degree. C. and the contents washed several times with cold 
toluene. No Zr was detected in the toluene washings. The toluene was 
removed under vacuum and 10 g of the resultant product extracted under 
N.sub.2 with boiling toluene in the presence of 20 g of silica SD 3217.50 
in the recovery flask. The content of the flask was transferred to a 
rotatory drier and the solvent removed to yield the free flowing catalyst. 
EXAMPLE 18 
Ethylene Homopolymerisation 
6.8 g of the supported metallocene containing polymer prepared in Example 
17 (0.078 mmol Zr) was premixed with 36 mmol of Al as MAO (WITCO, 10% in 
toluene) and the toluene removed under vacuum. 400 g of sodium chloride 
were introduced under N.sub.2 into a 2.5 liter stainless steel autoclave, 
the temperature increased to 80.degree. C. and the autoclave charged with 
the supported catalyst. Ethylene pressure was increased to 0.2 MPa and 
after 5 hrs the sodium chloride was removed by washing with water to yield 
420 g of polyethylene having a melt index of 0.7 g/10 min measured at 
190.degree. C. under a load of 2.16 kg (ASTM-D-1238 Condition E) and a 
bulk density of 0.42 g/cm.sup.3. 
By using a supported metallocene containing polymer a much lower melt index 
was achieved when compared with other metallocene catalysts as shown by 
comparative Example 13. 
EXAMPLE 19 
Preparation of Supported Metallocene-containing Polymer 
Metallocene containing polymer prepared according to Example 14 (0.27 g) 
was dissolved in 15 ml toluene at 80.degree. C. and added to 1.73 g 
Crosfield ES70 silica (precalcined in flowing N.sub.2 at 500.degree. C. 
for 4 hrs) with stirring. The solvent was removed in vacuum while 
maintaining the temperature at 80.degree. C. to yield a white, free 
flowing powder having 0.12% w/w Zr. 
EXAMPLE 20 
Ethylene Polymerization 
8.9 mmol of MAO (SCHERING, 30% in toluene) in 10 ml toluene were added to 
1.2 g of supported catalyst prepared as in Example 19 with stirring at 
25.degree. C. for 90 min. The solvent was removed under vacuum at 
25.degree. C. to leave a free flowing powder containing 0.084% w/w Zr. 
0.55 g (5.07.times.10-3 mmol Zr) of the powder was added to a 3 liter 
stirred gas phase polymerisation reactor. No further addition of MAO 
cocatalyst was made. Ethylene (0.8 MPa) was introduced at 75.degree. C. 
and the flow allowed to maintain constant reactor pressure. After 2 hrs 
the pressure was reduced rapidly and the reaction quenched using 
2-propanol to yield 30 g of polyethylene having Mw of 228,000, Mw/Mn of 
2.6 and 370 g PE/mmol Zr.h.b. 
TABLE 1 
__________________________________________________________________________ 
Density 
MI Impact 
Perforation Energy 
Output/pressure* 
Thickness 
Secant Modulus** 
g/cm.sup.3 
g/10 min 
g (dj) kg/h.b. .mu.m MPa 
__________________________________________________________________________ 
0.914 
2.9 550 (B) 
94 0.25 25 131 
0.916 
2.3 533 (B) 
67 0.25 38 132 
0.918 
2.8 271 (A) 
35 0.24 25 169 
__________________________________________________________________________ 
*measured on Kiefel/R040 (die diameter 100 mm, die gap 1.2 mm) 
**by ASTM D88288 
TABLE 2 
__________________________________________________________________________ 
Zr Content/% 
C.sub.2 flow 
Reaction 
Polymer 
Before 
After 
Example 
Metallocene 
Quantity/mmol 
MAO/mmol 
Solvent/ml 
Rate/ml/min 
Time/h 
Yield/g 
Washing 
Washing 
__________________________________________________________________________ 
14 Propenylzirconium 
4 240 40 33 6.17 9 0.87 0.76 
Dichloride 
15 Propenylzirconium 
4 240 40 6.5 21.17 4.4 0.70 0.70 
Dichloride 
16 Propenylzirconium 
4 240 40 30 6 9.8 0.68 0.74 
Dichloride 
__________________________________________________________________________