Process for the preparation of polyolefins having a broad molecular weight distribution

Polyolefins having a molecular weight distribution M.sub.w /M.sub.n of .gtoreq.3 and which may be monomodal, bimodal or multimodal are obtained by polymerization or copolymerization of olefins of the formula RCH.dbd.CHR, in which a catalyst system comprising an aluminoxane and a transition-metal component (metallocene) is used, the transition-metal component comprising at least one zirconocene of the formula I ##STR1## and at least one zirconocene of the formula Ia or alternatively at least 2 zirconocenes of the formula I.

It is known that metallocene catalysts in combination with aluminoxanes are 
capable of polymerizing olefins to give polyolefins having a narrow 
molecular weight distribution (M.sub.w /M.sub.n of 2-3) (J. Polym. Sci., 
Pol. Chem. Ed. 23 (1985) 2117; EP-A 302 424). Polyolefins of this type 
with a narrow distribution are suitable, for example, for applications in 
precision injection molding, injection molding in general and for the 
production of fibers. For numerous applications, such as, for example, 
thermoforming, extrusion, blow molding and for the production of 
polyolefin foams and films, broader or bimodal molecular weight 
distributions are required. 
For polyethylene, it has been proposed to achieve such products by using 
two or more metallocene catalysts in the polymerization (EP-A 128 045); 
however, the systems described are achiral catalysts and would give 
atactic polypropylene on polymermization of propene. However, atactic 
polypropylene is unsuitable as a structural material. 
The preparation of stereoblock polypropylene where M.sub.w /M.sub.n is 
13-15 is disclosed in DE-A 3 640 924. These catalyst systems are likewise 
unsuitable for the formation of polyolefins of high tacticity. 
Furthermore, the metallocene activities which can be achieved at 
industrially relevant polymerization temperatures and the molecular 
weights of polymer products are too low. In addition, the proposed 
catalysts give only an atactic polymer at such polymerization 
temperatures. 
EP-A 310 734 proposes catalyst systems comprising a mixture of a hafnocene 
and a zirconocene for the preparation of polypropylene. Products have 
broad to bimodal distributions where M.sub.w /M.sub.n is from 3.7 to 10.3 
If only the hafnocene catalyst is used, polypropylene with a broad 
distribution is obtained at a certain polymerization temperature, 
according to EP-A 355 439. 
Syndiotactic polypropylene having a broad distribution is described in EP-A 
387 691 (M.sub.w /M.sub.n up to 6.4) if a hafnocene is used. 
These processes have the common disadvantages of hafnium catalyst costs 
which are too high for industrial applications, together with a low 
polymerization activity, which additionally makes it necessary to carry 
out thorough, high-cost purification of the prepared polymer to remove 
catalyst residues. 
The object was thus to find a catalyst system and a process by means of 
which polyolefins having a broad, bimodal or multimodal distribution can 
be prepared and which avoid the disadvantages known from the prior art. 
The object is achieved by using a catalyst system comprising at least two 
stereorigid zirconocenes and an aluminum compound as cocatalyst. 
The invention thus relates to a process for the preparation of a polyolefin 
which has a molecular weight distribution M.sub.w /M.sub.n of .gtoreq.3.0 
and which may be monomodal, bimodal or multimodal, by polymerization or 
copolymerization of an olefin of the formula R.sup.a CH.dbd.CHR.sup.b in 
which R.sup.a and R.sup.b are identical or different and a hydrogen atom 
or a alkyl radical having 1 to 14 carbon atoms, or R.sup.a and R.sup.b, 
together with the atoms connecting them, can form a ring, at a temperature 
of from -60.degree. to 200.degree. C., at a pressure of from 0.5 to 100 
bar, in solution, in suspension or in the gas phase, in the presence of a 
catalyst comprising a transition-metal component (metallocene) and an 
aluminoxane of the formula II 
##STR2## 
for the linear type and/or of the formula III 
##STR3## 
for the cyclic type, where, in the formulae II and III, the radicals R may 
be identical or different and are a C.sub.1 -C.sub.6 -alkyl group, a 
C.sub.1 -C.sub.6 -fluoroalkyl group, a C.sub.6 -C.sub.18 -aryl group, a 
C.sub.1 -C.sub.6 -fluoroaryl group or a hydrogen, and n is an integer from 
0 to 50, or, instead of the aluminoxane, comprises a mixture of an 
aluminoxane of the formula II and/or of the formula III with a compound 
AlR.sub.3, which comprises using, as the transition-metal component, at 
least one zirconocene of the formula I and at least one zirconocene of the 
formula Ia or alternatively at least 2 zirconocenes of the formula I 
##STR4## 
in which R.sup.1 and R.sup.2 are identical or different and are a hydrogen 
atom, a C.sub.1 -C.sub.10 -alkyl group, a C.sub.1 -C.sub.10 -alkoxy group, 
a C.sub.6 -C.sub.10 -aryl group, a C.sub.6 -C.sub.10 -aryloxy group, a 
C.sub.2 -C.sub.10 alkenyl group, a C.sub.7 -C.sub.40 -arylalkyl group, a 
C.sub.7 -C.sub.40 -alkylaryl group, a C.sub.8 -C.sub.40 -arylalkenyl group 
or a halogen atom, 
R.sup.3 and R.sup.4 are identical or different and are a hydrogen atom, a 
halogen atom, a C.sub.1 -C.sub.10 -alkyl group, which may be halogenated, 
a C.sub.6 -C.sub.10 -aryl group, or a --NR.sub.2.sup.10, --SR.sup.10, 
--OSiR.sub.3.sup.10, --SIR.sub.3.sup.10 or --PR.sub.2.sup.10 radical in 
which R.sup.10 is a halogen atom, a C.sub.1 -C.sub.10 -alkyl group or a 
C.sub.6 -C.sub.10 -aryl group, 
R.sup.5 and R.sup.6 are identical or different and are as defined for 
R.sup.3 and R.sup.4, with the proviso that R.sup.5 and R.sup.6 are not 
hydrogen, 
R.sup.7 is 
##STR5## 
.dbd.BR.sup.11, .dbd.AlR.sup.11, --Ge--, --Sn, --O--, --S--, .dbd.SO, 
.dbd.SO.sub.2, .dbd.NR.sup.11, .dbd.CO, .dbd.PR.sup.11 or 
.dbd.P(O)R.sup.11, where 
R.sup.11, R.sup.12 and R.sup.13 are identical or different and are a 
hydrogen atom, a halogen atom, a C.sub.1 -C.sub.10 -alkyl group, a C.sub.1 
-C.sub.10 -fluoroalkyl group, a C.sub.6 -C.sub.10 -aryl group, a C.sub.6 
-C.sub.10 -fluoroaryl group, a C.sub.1 -C.sub.10 -alkoxy group, a C.sub.2 
-C.sub.10 -alkenyl group, a C.sub.7 -C.sub.40 -arylalkyl group, a C.sub.8 
-C.sub.40 -arylalkenyl group or a C.sub.7 -C.sub.40 -alkylaryl group, or 
R.sup.11 and R.sup.12 or R.sup.11 and R.sup.13, together with the atoms 
connecting them, in each case form a ring, and 
M.sup.1 is silicon, germanium or tin, 
R.sup.8 and R.sup.9 are identical or different and are as defined for 
R.sup.11, 
R.sup.14 and R.sup.15 are identical or different and are a monocyclic or 
polycyclic hydrocarbon radical which can form a sandwich structure 
together with the zirconium atom, and 
m and n are identical or different and are zero, 1 or 2, where m plus n is 
zero, 1 or 2. 
Alkyl is straight-chain or branched alkyl. Halogen (halogenated) refers to 
fluorine, chlorine, bromine or iodine, preferably fluorine or chlorine. 
R.sup.1 and R.sup.2 are identical or different and are a hydrogen atom, a 
C.sub.1 -C.sub.10 -, preferably C.sub.1 -C.sub.3 -alkyl group, a C.sub.1 
-C.sub.10 -, preferably C.sub.1 -C.sub.3 -alkoxy group, a C.sub.6 
-C.sub.10 -, preferably C.sub.6 -C.sub.8 -aryl group, a C.sub.6 -C.sub.10 
-, preferably C.sub.6 -C.sub.8 -aryloxy group, a C.sub.2 -C.sub.10 -, 
preferably C.sub.2 -C.sub.4 -alkenyl group, a C.sub.7 -C.sub.40 -, 
preferably C.sub.7 -C.sub.10 -arylalkyl group, a C.sub.8 -C.sub.40 -, 
preferably C.sub.7 -C.sub.12 -alkylaryl group, a C.sub.8 -C.sub.40 -, 
preferably C.sub.8 -C.sub.12 -arylalkenyl group, or a halogen atom, 
preferably chlorine. 
R.sup.3 and R.sup.4 are identical or different and are a hydrogen atom, a 
halogen atom, preferably fluorine, chlorine or bromine atom, a C.sub.1 
-C.sub.10 -, preferably C.sub.1 -C.sub.4 -alkyl group, which may be 
halogenated, a C.sub.6 -C.sub.10 -, preferably C.sub.6 -C.sub.8 -aryl 
group, a --NR.sub.2.sup.10, --SR.sup.10, --OSiR.sub.3.sup.10, 
SiR.sub.3.sup.10 or --PR.sub.2.sup.10 radical in which R.sup.10 is a 
halogen atom preferably a chlorine atom, or a C.sub.1 -C.sub.10 -, 
preferably C.sub.1 -C.sub.3 -alkyl group or a C.sub.6 -C.sub.10 -, 
preferably C.sub.6 -C.sub.8 -aryl group. R.sup.3 and R.sup.4 are 
particularly preferably hydrogen. 
R.sup.5 and R.sup.6 are identical or different, preferably identical, and 
are as defined for R.sup.3 and R.sup.4, with the proviso that R.sup.5 and 
R.sup.6 cannot be hydrogen. R.sup.5 and R.sup.6 are preferably (C.sub.1 
-C.sub.4)-alkyl, which may be halogenated, such as methyl, ethyl, propyl, 
isopropyl, butyl, isobutyl or trifluoromethyl, in particular methyl. 
R.sup.7 is 
##STR6## 
.dbd.BR.sup.11, .dbd.AlR.sup.11, --Ge--, --Sn, --O--, --S--, .dbd.SO, 
.dbd.SO.sub.2, .dbd.NR.sup.11, .dbd.CO, .dbd.PR.sup.11 or 
.dbd.P(O)R.sup.11, where R.sup.11, R.sup.12 and R.sup.13 are identical or 
different and are hydrogen atoms, halogen atoms, a C.sub.1 -C.sub.10 -, 
preferably C.sub.1 -C.sub.4 -alkyl group, in particular methyl group, a 
C.sub.1 -C.sub.10 -fluoroalkyl group, preferably CF.sub.3 group, a C.sub.6 
-C.sub.10 -, preferably C.sub.6 -C.sub.8 -aryl group, a C.sub.6 -C.sub.10 
-fluoroaryl group, preferably pentafluorophenyl group, a C.sub.1 -C.sub.10 
-, preferably C.sub.1 -C.sub.4 -alkoxy group, in particular methoxy group, 
a C.sub.2 -C.sub.10 -, preferably C.sub.2 -C.sub.4 -alkenyl group, C.sub.7 
-C.sub.40 -, preferably C.sub.7 -C.sub.10 -arylalkyl group, a C.sub.8 
-C.sub.40 -, preferably C.sub.8 -C.sub.12 -arylalkenyl group, or a C.sub.7 
-C.sub.40 -, preferably C.sub.7 -C.sub.12 -alkylaryl group, or R.sup.11 
and R.sup.12 or R.sup.11 and R.sup.13, together with the atoms connecting 
them, in each case form a ring. 
M.sup.1 is silicon, germanium or tin, preferably silicon or germanium. 
R.sup.7 is preferably .dbd.CR.sup.11 R.sup.2, .dbd.SiR.sup.11 R.sup.12, 
.dbd.GeR.sup.11 R.sup.12, --O--, --S--, .dbd.SO, .dbd.PR.sup.11 or 
.dbd.P(O)R.sup.11. 
R.sup.8 and R.sup.9 are identical or different and are as defined for 
R.sup.11. 
m and n are identical or different and are zero, 1 or 2, preferably zero or 
1, where m plus n is zero, 1 or 2, preferably zero or 1. 
R.sup.14 and R.sup.15 are preferably fluorenyl, indenyl or 
cyclopentadienyl, it being possible for these parent structures also to 
carry additional substituents as defined for R.sup.11. 
Particularly preferred metallocenes are thus those in which, in the formula 
I, R.sup.1 and R.sup.2 are identical or different and are methyl or 
chlorine, R.sup.3 and R.sup.4 are hydrogen, R.sup.5 and R.sup.6 are 
identical or different and are methyl, ethyl or trifluoromethyl, R.sup.7 
is a 
##STR7## 
radical, and n plus m is zero or 1, in particular the compounds listed in 
the working examples. 
Of the compounds I mentioned in the working examples, 
rac-dimethylsilyl(2-methyl-1-indenyl).sub.2 zirconium dichloride, 
rac-ethylene(2-methyl-1-indenyl).sub.2 zirconium dichloride, 
rac-diphenylsilyl(2-methyl-1-indenyl).sub.2 zirconium dichloride, 
rac-methylethylene(2-methyl-1-indenyl).sub.2 zirconium dichloride and 
racphenyl(methyl)silyl(2-methyl-1-indenyl).sub.2 zirconium dichloride are 
of particular importance. 
The particularly preferred metallocenes of the formula Ia are those in 
which R.sup.1 and R.sup.2 are identical or different and are methyl or 
chlorine, R.sup.7 is a 
##STR8## 
radical n+m is zero or 1 and 
R.sup.14 and R.sup.15 are identical or different and are fluorenyl, indenyl 
or substituted cyclopentadienyl, in particular the compounds Ia listed in 
the working examples. 
Of particular importance are thus rac-phenyl(methyl)silyl(indenyl).sub.2 
zirconium dichloride, diphenylmethylene(9-fluorenyl) (cyclopentadienyl) 
zirconium dichloride, isopropylidene (9-fluorenyl) (cyclopentadienyl) 
zirconium dichloride, rac-dimethylsilyl 
(2,3,5-trimethyl-1-cyclopentadienyl).sub.2 zirconium dichloride, 
rac-dimethylsilyl(indenyl).sub.2 zirconium dichloride, 
rac-dimethylgermyl(indenyl).sub.2 zirconium dichloride, 
rac-dimethylsilyl(indenyl).sub.2 dimethylzirconium, 
rac-phenyl(vinvl)silyl(indenyl).sub.2 zirconium dichloride, 
##STR9## 
rac-dimethylsilyl (2,4-dimethylcyclopentadienyl).sub.2 zirconium 
dichloride, racisopropylidene(idenyl).sub.2 zirconium dichloride, 
racdimethylsilyl (2-methyl-4,5,6,7-tetrahydro-1-indenyl).sub.2 zirconium 
dichloride, rac-ethylene(indenyl).sub.2 zirconium dichloride, 
rac-methylene(3-t-butyl-1-cyclopentadienyl).sub.2 zirconium dichloride and 
rac-dimethylsilyl(4,7-dimethyl-1-idenyl).sub.2 zirconium dichloride. 
The metallocenes having C.sub.s symmetry (subgroup of compounds of the 
formula Ia; for example R.sup.11 R.sup.12 
C(fluorenyl)(cyclopentadienyl)dimethylzirconium) are employed for the 
preparation of the syndiotactic block in the polyolefin. 
For the purposes of the present invention, the term C.sub.s symmetry means 
that the corresponding metallocenes have a mirror plane perpendicular to 
the plane passing through Zr, R.sup.1 and R.sup.2. The bisecting line of 
the angle .notlessthan.R.sup.1 -Zr-R.sup.2 extends in this mirror plane. 
This consideration of symmetry is restricted to part of the zirconocene 
molecule, i.e. the --(CR.sup.8 R.sup.9).sub.n --R.sup.7 --(CR.sup.8 
R.sup.9).sub.m -- bridge is not taken into account. Furthermore, the term 
C.sub.s symmetry should be understood in formal or idealized terms. Thus, 
for example, shifts in said moiety which may be caused by the bridge and 
can only be explained via the structure are not considered for the 
purposes of the present invention. 
The chiral metallocenes are employed as racemates for the preparation of 
highly isotactic polyolefins. However, it is also possible to use the pure 
R- or S-form. These pure stereoisomeric forms allow preparation of an 
optically active polymer. However, the meso-form of the metallocenes 
should be removed since the polymerization-active center (the metal atom) 
in these compounds is no longer chiral due to mirror symmetry at the 
central metal and can therefore not produce any highly isotactic polymer. 
If the meso-form is not removed, atactic polymer is formed alongside 
isotactic polymer. For certain applications--soft moldings for 
example--this may be thoroughly desirable. 
The principle of resolution of stereoisomers is known. 
The metallocenes I and Ia can be prepared by the principle of the following 
reaction scheme: 
##STR10## 
(cf. Journal of Organomet. Chem. (1985) 63-67 and EP-A 320762). 
The choice of the metallocenes for the polymerization of olefins to give 
polyolefins having a broad or multimodal distribution can take place by 
means of a test polymerization for each metallocene. 
In this test, the olefin is polymerized to the polyolefin and the mean 
molecular weight M.sub.w thereof and the molecular weight distribution 
M.sub.w /M.sub.n thereof are determined by means of gel permeation 
chromatography. Depending on the desired molecular weight distribution, 
the metallocenes are then combined. 
Taking into account the polymerization activities, it is then possible, by 
means of computer simulation of the combined gel permeation curves, to 
directly produce any desired molecular weight distribution via the type of 
metallocenes and via the ratio of the amounts of the metallocenes to one 
another. 
The number of zirconocenes to be used according to the invention is 
preferably 2 or 3, in particular 2. However, it is also possible to use a 
greater number (such as, for example, 4 or 5) in any desired combination 
of I and Ia. 
By including the polymerization activities and molecular weights at various 
polymerization temperatures, in the presence of hydrogen as molecular 
weight regulator or in the presence of comonomers, the computer simulation 
model can be further refined and the applicability of the process 
according to the invention further improved. 
The cocatalyst used is an aluminoxane of the formula II and/or III, where n 
is an integer from 0 to 50, preferably 10 to 35. 
The radicals R are preferably identical and are methyl, isobutyl, phenyl or 
benzyl, particularly preferably methyl. 
If the radicals R are different, they are preferably methyl and hydrogen or 
alternatively methyl and isobutyl, hydrogen or isobutyl preferably being 
present to the extent of 0.01-40% (number of radicals R). The aluminoxane 
can be replaced as cocatalyst in the polymerization by a mixture 
comprising aluminoxane and AlR.sub.3, where R is as defined above. 
The aluminoxane can be prepared in various ways by known processes. One of 
the methods is, for example, to react an aluminum hydrocarbon compound 
and/or a hydridoaluminum hydrocarbon compound with water (gaseous, solid, 
liquid or bound--for example as water of crystallization) in an inert 
solvent (such as, for example, toluene). To prepare an aluminoxane 
containing different alkyl groups R, two different trialkylaluminum 
compounds (AlR.sub.3 +AlR'.sub.3), corresponding to the desired 
composition, are reacted with water (cf. S. Pasynkiewicz, Polyhedron 9 
(1990) 429 and EP-A 302 424). 
The precise structure of the aluminoxanes II and III is unknown. 
Irrespective of the preparation method, all aluminoxane solutions have in 
common a varying content of unreacted aluminum starting compound, which is 
in free form or as an adduct. 
It is possible, before use in the polymerization reaction, to preactivate 
the metallocenes, in each case separately or together as a mixture, by 
means of an aluminoxane of the formula (II) and/or (III). This 
significantly increases the polymerization activity and improves the 
particle morphology. 
The preactivation of the metallocenes is carried out in solution. The 
metallocenes are preferably dissolved, as solids, in a solution of the 
aluminoxane in an inert hydrocarbon. Suitable inert hydrocarbons are 
aliphatic or aromatic hydrocarbons. Toluene or a C.sub.6 -C.sub.10 
-hydrocarbon is preferably used. 
The concentration of the aluminoxane in the solution is in the range from 
about 1% by weight to the saturation limit, preferably from 5 to 30% by 
weight, in each case based on the total solution. The metallocenes can be 
employed in the same concentration, but are preferably employed in an 
amount of from 10.sup.-4 -1 mole per mole of aluminoxane. The 
preactivation time is from 5 minutes to 60 hours, preferably from 5 to 60 
minutes. The temperature used is from -78.degree. C. to 100.degree. C., 
preferably from 0.degree. to 70.degree. C. 
The metallocenes may also be prepolymerized or applied to a support. 
Prepolymerization is preferably carried out using the ( or one of the ) 
olefin( s ) employed in the polymerization. 
Examples of suitable supports are silica gels, aluminum oxides, solid 
aluminoxane or other inorganic support materials. Another suitable support 
material is a polyolefin powder in finely divided form. 
A further possible embodiment of the process according to the invention 
comprises using a salt-like compound of the formula R.sub.x NH.sub.4-x 
BR'.sub.4 or of the formula R.sub.3 PHBR'.sub.4 as cocatalyst in place of 
or in addition to an aluminoxane. In these formulae, x=1, 2 or 3, R=alkyl 
or aryl, identical or different, and R'=aryl, which may also be 
fluorinated or partially fluorinated. In this case, the catalyst comprises 
the product of the reaction of the metallocenes with one of said compounds 
(cf. EP-A 277 004). 
In order to remove the catalyst poisons present in the olefin, purification 
by means of an alkylaluminum compound, for example AlMe.sub.3 or 
AlEt.sub.3, is advantageous. This purification can be carried out either 
in the polymerization system itself, or the olefin is brought into contact 
with the Al compound before addition to the polymerization system and is 
subsequently removed again. 
The polymerization or copolymerization is carried out in a known manner in 
solution, in suspension or in the gas phase, continuously or batchwise, in 
one or more steps, at a temperature of from -60.degree. to 200.degree. C., 
preferably from 20.degree. to 80.degree. C. Olefins of the formula R.sup.a 
--CH.dbd.CH--R.sup.b are polymerized or copolymerized. In this formula 
R.sup.a and R.sup.b are identical or different and are hydrogen atoms or 
alkyl radicals having 1 to 14 carbon atoms. However, R.sup.a and R.sup.b 
may also form a ring with the carbon atoms connecting them. Examples of 
such olefins are ethylene, propylene, 1-butene, 1-hexene, 
4-methyl-1-pentene, 1-octene, norbornene and norbornadiene. In particular, 
propylene and ethylene are polymerized. 
If necessary, hydrogen is added as molecular weight regulator. The various 
hydrogen-reactivities of the metallocenes and the possibility of changing 
the amount of hydrogen during the polymerization can result in a further 
desired broadening of the molecular weight distribution. 
The overall pressure in the polymerization system is from 0.5 to 100 bar. 
The polymerization is preferably carried out in the industrially 
particularly interesting pressure range of from 5 to 64 bar. 
The metallocenes are used in a concentration, based on the transition 
metal, of from 10.sup.-3 to 10.sup.-8 mol, preferably from 10.sup.-4 to 
10.sup.-7 mol, of transition metal per dm.sup.3 of solvent or per dm.sup.3 
of reactor volume. The aluminoxane or the aluminoxane/AlR.sub.3 mixture is 
used in a concentration of from 10.sup.-5 to 10.sup.-1 mol, preferably 
from 10.sup.-4 to 10.sup.-2 mol, per dm.sup.3 of solvent or per dm.sup.3 
of reactor volume. In principle, however, higher concentrations are also 
possible. 
If the polymerization is carried out as a suspension or solution 
polymerization, an inert solvent which is customary for the Ziegler 
low-pressure process is used. For example, the polymerization is carried 
out in an aliphatic or cycloaliphatic hydrocarbon; the examples of these 
which may be mentioned are butane, pentane, hexane, heptane, decane, 
isooctane, cyclohexane and methylcyclohexane. It is also possible to use a 
gasoline or hydrogenated diesel oil fraction. Toluene can also be used. 
The polymerization is preferably carried out in the liquid monomer. 
If inert solvents are used, the monomers are metered in in gaseous or 
liquid form. 
The polymerization can take as long as desired, since the catalyst system 
used according to the invention only exhibits a slight decrease in the 
polymerization activity with time. 
The process according to the invention is distinguished by the fact that 
the metallocenes described give polymers having a broad, bimodal or 
multimodal molecular weight distribution, high molecular weight, high 
stereospecificity and good particle morphology in the industrially 
interesting temperature range between 20.degree. and 80.degree. C. with 
high polymerization activity. 
The polymers according to the invention are particularly suitable for the 
production of films, in particular transparent films, thermoforming 
applications, polyolefin foams, extrusion applications and for the 
production of transparent hollow articles and for blow molding in general.

The examples below are intended to illustrate the invention in greater 
detail. 
The following abbreviations are used: 
##EQU1## 
EXAMPLE 1 
A dry 24 dm.sup.3 reactor was flushed with nitrogen and filled with 12 
dm.sup.3 of liquid propylene. 39 cm.sup.3 of a toluene solution of 
methylaluminoxane (corresponding to 52 mmol of Al, mean degree of 
oligomerization of the methylaluminoxane was n=19) were then added, and 
the batch was stirred at 30.degree. C. for 15 minutes. 
In parallel, 13.5 mg (0.025 mmol) of 
rac-phenyl(methyl)silyl(2-methyl-1-indenyl).sub.2 zirconium dichloride and 
51.0 mg (0.10 mmol) of rac-phenyl(methyl)silyl(1-indenyl)zirconium 
dichloride were dissolved in 15 cm.sup.3 of a toluene solution of 
methylaluminoxane (20 mmol), and the solution was introduced into the 
reactor after 15 minutes. 
The mixture was polymerized at 30.degree. C. for 3 hours. The 
polymerization was terminated by addition of 12 1 of CO.sub.2 gas. 1.85 kg 
of polypropylene were obtained, corresponding to an activity of the 
metallocene mixture of 9.6 kg of PP/g of metallocene.times.h. 
VN=331 cm.sup.3 /g; M.sub.w =411,000 g/mol, M.sub.w /M.sub.n =8.5; 
II=96.9%. 
EXAMPLE 2 
Example 1 was repeated, but the metallocene mixture components employed 
were 11.2 mg (0.025 mmol) of racethylene(2-methyl-1-indenyl).sub.2 
zirconium chloride and 13.9 mg (0.025 mmol) of 
diphenylmethylene(9-fluorenyl)(cyclopentadienyl) zirconium dichloride; the 
polymerization temperature was 60.degree. C. and the polymerization time 
was 1 hour. 
2.45 kg of polypropylene were obtained, corresponding to an activity of the 
metallocene mixture of 97.6 kg of PP/g of metallocene.times.h. 
VN=255 cm.sup.3 /g; M.sub.w =385,000 g/mol, M.sub.w /M.sub.n =7.5. 
The resultant polymer could be separated by fractionation into a fraction 
of isotactic polypropylene (II&gt;96%) and a fraction of syndiotactic 
polypropylene (SI&gt;96%). The mixing ratio was about 1:1. 
EXAMPLE 3 
Example 1 was repeated, but the metallocene mixture components employed 
were 5.4 mg (0.010 mmol) of racphenyl (methyl) silyl 
(2-methyl-1-indenyl).sub.2 zirconium dichloride and 5.4 mg (0.013 mmol) of 
dimethylmethylene(9-fluorenyl) (cyclopentadienyl) zirconium dichloride, 
the polymerization temperature was 70 .degree. C. and the polymerization 
time was 1 hour. 
2.2 kg of a mixture of about two parts of isotactic polypropylene and one 
part of syndiotactic polypropylene were obtained, corresponding to an 
activity of the metallocene mixture of 203.7 kg of PP/g of 
metallocene.times.h. 
VN=172 cm.sup.3 /g; M.sub.w =186,500 g/mol, M.sub.w /M.sub.n =3.0. 
EXAMPLE 4 
Example 1 was repeated, but the metallocene mixture components employed 
were 4.8 mg (0.01 mmol) of racMe.sub.2 Si(2-methyl-1-indenyl).sub.2 
zirconium dichloride and 21.2 mg (0.05 mmol) of rac-Me.sub.2 
Si(2,3,5-trimethylcyclopentadienyl).sub.2 zirconium dichloride, and the 
polymerization temperature was 50.degree. C. 
2.57 kg of polypropylene were obtained, corresponding to an activity of the 
metallocene mixture of 32.9 kg of PP/g of metallocene.times.h. 
VN=194 cm.sup.3 /g; M.sub.w =261,000 g/mol, M.sub.w /M.sub.n =7.9, 
II=98.5%. 
EXAMPLE 5 
Example 1 was repeated, but the metallocene mixture components employed 
were 4.5 mg (0.008 mmol) of 
racphenyl(methyl)silyl(2-methyl-1-indenyl).sub.2 zirconium dichloride and 
6.6 mg (0.015 mmol) of rac-dimethylsilyl(indenyl)2zirconium dichloride. 
The polymerization time was one hour, and the polymerization temperature 
was 50.degree. C. 
1.35 kg of polypropylene were obtained, corresponding to an activity of the 
metallocene mixture of 121.6 kg of PP/g of metallocene.times.h. 
VN=154 cm.sup.3 /g; M.sub.w =133,000 g/mol, M.sub.w /M.sub.n =5.2, 
II=96.0%. 
EXAMPLE 6 
Example 1 was repeated, but the metallocene mixture components employed 
were 2.4 mg (0.005 mmol) of racdimethylsilyl(2-methyl-1-indenyl).sub.2 
zirconium dichloride and 2.5 mg (0.005 mmol) of 
rac-dimethylgermyl(indenyl).sub.2 zirconium dichloride. The two 
metallocenes were dissolved separately, each in 7.5 cm.sup.3 of a toluene 
solution of methylaluminumoxane, and after 15 minutes these solutions were 
metered into the polymerization system. The mixture was polymerized at 
70.degree. C. for 1 hour. 
1.57 kg of polypropylene were obtained, corresponding to an activity of the 
metallocene system of 320.4 kg of PP/g of metallocene.times.h. 
VN=105 cm.sup.3 /g; M.sub.w =114,000 g/mol, M.sub.w /M.sub.n =4.1, 
II=96.3%. 
EXAMPLE 7 
Example 6 was repeated, but the metallocenes used were 4.8 mg (0.01 mmol) 
of rac-dimethylsilyl(2-methyl-1-indenyl).sub.2 zirconium dichloride and 
1.5 mg (0.004 mmol) of rac-dimethylsilyl(indenyl).sub.2 dimethylzirconium. 
2.08 kg of polypropylene were obtained, corresponding to an activity of the 
metallocene system of 330.2 kg of PP/g of metallocene.times.h. 
VN=121 cm.sup.3 /g; M.sub.w =101,900 g/mol, M.sub.w /M.sub.n =4.0, 
II=96.0%. 
EXAMPLE 8 
Example 6 was repeated, but the metallocenes used were 2.7 mg (0.005 mmol) 
of rac-phenyl(methyl)silyl(2-methyl1-indenyl).sub.2 zirconium dichloride 
and 20.5 mg (0.04 mmol) i 10 of rac-phenyl (vinyl) silyl (indenyl).sub.2 
zirconium dichloride. 
2.17 kg of polypropylene were obtained, corresponding to an activity of the 
metallocene system of 93.5 kg of PP/g of metallocene.times.h. 
VN=102 cm.sup.3 /g; M.sub.w =79,400 g/mol, M.sub.w /M.sub.n =3.3, II=96.9%. 
EXAMPLE 9 
Example 6 was repeated, but the metallocenes used were 4.8 mg (0.01 mmol) 
of rac-dimethylsilyl(2-methyl-1-indenyl).sub.2 zirconium dichloride and 
9.2 mg (0.02 mmol) of 
##STR11## 
1.82 kg of polypropylene were obtained, corresponding to an activity of the 
metallocene system of 130 kg of PP/g of metallocene. 
VN=145 cm.sup.3 /g; M.sub.w =185,500 g/mol, M.sub.w /M.sub.n =3.6, 
II=96.8%. 
EXAMPLE 10 
Example 6 was repeated, but the metallocenes used were 2.7 mg (0.005 mmol) 
of rac-phenyl(methyl)silyl(2-methyl-1-indenyl).sub.2 zirconium dichloride 
and 2.4 mg (0.006 mmol) of 
rac-dimethylsilyl(2,4-dimethylcyclopentadienyl).sub.2 -zirconium 
dichloride. 
1.31 kg of polypropylene were obtained, corresponding to an activity of the 
metallocene system of 256.9 kg of PP/g of metallocene.times.h. 
VN=118 cm.sup.3 /g; M.sub.w =129,500 g/mol, M.sub.w /M.sub.n =3.8, 
II=98.0%. 
EXAMPLE 11 
Example 1 was repeated, but the metallocenes used were 26.9 mg (0.05 mmol) 
of rac-phenyl(methyl)silyl(2-methyl1-indenyl).sub.2 zirconium dichloride 
and 32.5 mg (0.08 mmol) of 
rac-dimethylsilyl(2,4-dimethylcyclopentadienyl).sub.2 zirconium 
dichloride. The polymerization time was 2 hours. 2.32 kg of polypropylene 
were obtained, corresponding to an activity of the metallocene system of 
19.5 kg of PP/g of metallocene.times.h. 
VN=386 cm.sup.3 /g; M.sub.w =436,000 g/mol, M.sub.w /M.sub.n =7.2, 
II=98.5%. 
EXAMPLE 12 
Example 1 was repeated, but the metallocenes used were 9.2 mg (0.02 mmol) 
of rac-methylethylene(2-methyl-1-indenyl).sub.2 zirconium dichloride and 
8.6 mg (0.02 mmol) of rac-dimethylmethylene(1-indenyl).sub.2 zirconium 
dichloride, and the polymerization temperature was 50.degree. C. 1.42 kg 
of polypropylene were obtained, corresponding to an activity of the 
metallocene system of 26.6 kg of PP/g of metallocene.times.h. 
VN=101 cm.sup.3 /g; M.sub.w =123,000 g/mol, M.sub.w /M.sub.n =8.5, 
II=91.6%. 
EXAMPLE 13 
A dry 24 dm.sup.3 reactor was flushed with nitrogen and filled with 24 
dm.sup.3 (s.t.p.) of hydrogen and 12 dm.sup.3 of liquid propylene. 
10 ml of a toluene solution of trimethylaluminum (corresponding to 26 mol 
of AlMe.sub.3) were then added, and the batch was stirred at 40.degree. C. 
for 15 minutes. 
In parallel, 5.4 mg (0.01 mmol) of rac-phenyl(methyl)silyl 
(2-methyl-1-indenyl ).sub.2 zirconium dichloride and 4.9 mg (0.01 mmol) of 
rac-dimethylgermyl(indenyl).sub.2 zirconium dichloride were dissolved in 
15 cm.sup.3 of methylaluminoxane solution (20 mmol of Al, toluene), and, 
after 15 minutes, the solution was introduced into the reactor. The 
reactor contents were heated to 65.degree. C. in 3 minutes and polymerized 
at this temperature for one hour. 
The polymerization was terminated by addition of 12 l of CO.sub.2 gas, 
excess propylene was removed in gaseous form, and the polymer powder was 
dried at 80.degree. C./100 mbar. 
2.25 kg of polypropylene were obtained, corresponding to an activity of the 
metallocene mixture of 218.5 kg of PP/g of metallocene.times.h. 
VN=91 cm.sup.3 /g; M.sub.w =72,800 g/mol, M.sub.w /M.sub.n =4.6, II=96.8%. 
EXAMPLE 14 
Example 1 was repeated, but the metallocenes used were 5.4 mg (0.010 mmol) 
of rac-phenyl(methyl)silyl(2-methyl-1-indenyl).sub.2 zirconium dichloride 
and 27.0 mg (0.056 mmol) of 
rac-dimethylsilyl(2-methyl-4,5,6,7-tetrahydro-1-indenyl).sub.2 zirconium 
dichloride, the polymerization temperature was 50.degree. C., and the 
polymerization time was 1.5 hours. 
1.51 kg of polypropylene were obtained, corresponding to an activity of the 
metallocene system of 31.1 kg of PP/g of metallocene.times.h. 
VN=187 cm.sup.3 /g; M.sub.w =132,500 g/mol, M.sub.w /M.sub.n =4.1, 
II=97.6%. 
EXAMPLE 15 
Example 1 was repeated, but the metallocenes used were 4.8 mg (0.010 mmol) 
of rac-dimethylsilyl(2-methyl-1-indenyl).sub.2 zirconium dichloride and 
7.0 mg (0.017 mmol) of rac-ethylene(1-indenyl).sub.2 zirconium dichloride. 
The polymerization temperature was 50.degree. C. and the polymerization 
duration was 1 hour. 
1.50 kg of polypropylene were obtained, corresponding to an activity of the 
metallocene system of 127.1 kg of PP/g of metallocene.times.h. 
VN=125 cm.sup.3 /g; M.sub.w =129,500 g/mol, M.sub.w /M.sub.n =5.3, II=5.4%. 
EXAMPLE 16 
Example 1 was repeated, but the metallocenes used were 6.0 mg (0.010 mmol) 
of rac-diphenylsilyl(2-methyl-1-indenyl).sub.2 zirconium dichloride, 6.0 
mg (0.013 mmol) of rac-dimethylsilyl(1-indenyl).sub.2 zirconium dichloride 
and 36.0 mg (0.083 mmol) of 
rac-dimethylsilyl(2,3,5-trimethylcyclopentadienyl).sub.2 zirconium 
dichloride, the polymerization temperature was 40.degree. C. and the 
polymerization duration was 2 hours. 
1.79 kg of polypropylene were obtained, corresponding to an activity of the 
metallocene system of 18.6 kg of PP/g of metallocene.times.h. 
VN=267 cm.sup.3 /g, M.sub.w =293,000 g/mol, M.sub.w /M.sub.n =5.7, 
II=98.0%, MFI (230/5)=24.6 g/10 min. 
EXAMPLE 17 
A dry 24 dm.sup.3 reactor was flushed with propylene and filled with 12 
dm.sup.3 of liquid propylene and with 20 ml of a toluene solution of 
trimethylaluminum (corresponding to 52 mmol of AlMe.sup.3). The batch was 
stirred at 30.degree. C. for 15 minutes. 
In parallel, 3.0 mg (0.005 mmol) of 
rac-diphenylsilyl(2-methyl-1-indenyl).sub.2 zirconium dichloride, 2.0 mg 
(0.004 mmol) of rac-dimethylsilyl(2-methyl-1-indenyl).sub.2 zirconium 
dichloride and 2.0 mg (0.004 mmol) of racdimethylgermyl(1-indenyl).sub.2 
zirconium dichloride were dissolved in 20 cm.sup.3 of methylaluminoxane 
solution (27 mmol of Al, toluene), and, after 15 minutes, the solution was 
introduced into the reactor. The mixture was polymerized at 65.degree. C. 
for 1.5 hours. 
1.59 kg of polypropylene were obtained, corresponding to an activity of the 
metallocene system of 151.4 kg of PP/g of metallocene.times.h. 
VN=153 cm.sup.3 /g; M.sub.w =195,000 g/mol, M.sub.w /M.sub.n =5.8, 
II=96.0%, MFI (230/5)=87 g/10 min. 
EXAMPLE 18 
Example 1 was repeated, but the metallocenes used were 6.0 mg (0.01 mmol) 
of rac-diphenylsilyl(2-methyl-1-indenyl).sub.2 zirconium dichloride and 
45.0 mg (0.108mmol) of rac-methylene(3-t-butyl-1-cyclopentadienyl).sub.2 
zirconium dichloride, the polymerization temperature was 40.degree. C. and 
the polymerization duration was 4 hours. 
1.63 kg of polypropylene were obtained, corresponding to an activity of the 
metallocene system of 8.0 kg of PP/g of metallocene.times.h. 
VN=358 cm.sup.3 /g; M.sub.w =354,000 g/mol, M.sub.w /M.sub.n =12.5, 
II=93.5%. 
EXAMPLE 19 
Example 1 was repeated, but the metallocenes used were 6.0 mg (0.010 mmol) 
of rac-diphenylsilyl(2-methyl-1-indenyl).sub.2 zirconium dichloride and 
6.0 mg (0.012 mmol) of rac-dimethylsilyl(4,7-dimethyl-1-indenyl).sub.2 
zirconium dichloride, the polymerization temperature was 40.degree. C. and 
the polymerization duration was 2 hours. 
0.85 kg of polypropylene were obtained, corresponding to an activity of the 
metallocene system of 35.4 kg of PP/g of metallocene.times.h. 
VN=324 cm.sup.3 /g; M.sub.w =352,500 g/mol, M.sub.w /M.sub.n =15.5, 
II=95.3%. 
EXAMPLE 20 
Example 1 was repeated, but the metallocenes used were 6.0 mg (0.0 10 mmol 
) of rac-diphenylsilyl (2-methyl-1-indenyl).sub.2 zirconium dichloride and 
7.2 mg (0.016 mmol) of rac-ethylene (2-methyl-1-indenyl).sub.2 zirconium 
dichloride. 
The polymerization temperature was 50.degree. C. and the polymerization 
duration was 2 hours. 
1.44 kg of polypropylene were obtained, corresponding to an activity of the 
metallocene system of 54.6 kg of PP/g of metallocene.times.h. 
VN=227 cm.sup.3 /g; M.sub.w =406,000 g/mol, M.sub.w /M.sub.n =8.0, 
II=97.1%. 
EXAMPLE 21 
Example 20 was repeated, but in addition 75 g of ethylene were metered in 
continuously during the polymerization. The polymerization temperature was 
60.degree. C. and the polymerization time was 1 hour. 
1.65 kg of ethylene-propylene copolymer were obtained, corresponding to an 
activity of the metallocene system of 15 125.0 kg of copolymer/g of 
metallocene.times.h. 
VN=291 cm.sup.3 /g; M.sub.w =387,000 g/mol, M.sub.w /M.sub.n =7.4; 4.2% 
ethylene content with ethylene units predominantly incorporated in an 
isolated manner (.sup.13 C--NMR analysis). 
EXAMPLE 22 
Example 21 was repeated, but 300 g of ethylene were only added after a 
polymerization time of 30 minutes. 
1.49 kg of copolymer were obtained, corresponding to an activity of the 
metallocene system of 112.9 kg of copolymer/g of metallocene.times.h. 
VN=357 cm.sup.3 g; M.sub.w =449,000 g/mol, M.sub.w /M.sub.n =8.8. The 
polymer product can be separated by fractionation (decane, diethyl ether) 
into a polypropylene component and an ethylene-propylene rubber component. 
Ethylene content of the copolymer 18.4%. 
EXAMPLE 23 
A dry 150 dm.sup.3 reactor was flushed with nitrogen and filled at 
20.degree. C. with 80 dm.sup.3 of a gasoline fraction with the aromatics 
removed and with a boiling range of 100.degree.-120.degree. C. The gas 
space was then flushed free from nitrogen by injecting 2 bar of propylene 
and releasing the pressure, and repeating this cycle four times. 
50 l of liquid propylene were added, and 64 cm.sup.3 of a toluene solution 
of methylaluminoxane (corresponding to 100 mmol of Al, molecular weight 
990 g/mol according to cryoscopic determination) were added and the 
reactor contents were heated to 50.degree. C. 
Hydrogen was metered in to give a hydrogen content in the gas space of the 
reactor of 0.1%, and this content was then maintained during the entire 
polymerization time by topping up (monitoring on-line by gas 
chromatography). 
15.3 mg of rac-methylethylene(2-methyl-1-indenyl).sub.2 zirconium 
dichloride (0.033 mmol), 6.3 mg of 
rac-phenyl(methyl)silyl(2-methyl-1-indenyl).sub.2 zirconium dichloride 
(0.012 mmol) and 7.0 mg of rac-diphenylsilyl(2-methyl-1-indenyl).sub.2 
zirconium dichloride (0.012 mmol) were dissolved in 32 ml of a toluene 
solution of methylaluminoxane (corresponding to 50 mmol of Al) and, after 
15 minutes, the solution was introduced into the reactor. 
The reactor was kept at a polymerization temperature of 50.degree. C. for 7 
hours by cooling, the polymerization was then terminated by addition of 2 
bar of CO.sub.2 gas, and the polymer formed was separated from the 
suspension medium in a pressure filter. The product was dried for 24 hours 
at 80.degree. C./200 mbar. 16.4 kg of polymer powder, were obtained 
corresponding to a metallocene activity of 81.9 kg of PP/g of 
metallocene.times.h. 
VN=206 cm.sup.3 /g; M.sub.w =248,000 g/mol; M.sub.w /M.sub.n =3.4 
II=97.9%; MFI (230/5)=32 g/10 min, m.p.: 151.degree. C. 
The product had the following mechanical data: Modulus of elasticity in 
tension (in accordance with DIN 53457-Z) 1,430 N/mm.sup.2 ; notched impact 
strength (a.sub.n in accordance with DIN 53453) 5 mJ/mm.sup.2 at 
23.degree. C.; Izod impact strength (in accordance with ISO 180/1 C) 69 
mJ/mm.sup.2 at 23.degree. C. and 12 mJ/mm.sup.2 at -30.degree. C.; Izod 
notched impact strength (according to ISO 180/1 A) 3 mJ/mm.sup.2 at 
23.degree. C. and 2 mJ/mm.sup.2 at -30.degree. C.; ball indentation 
hardness (pressing, conditioned, 358 N) 84 N/mm.sup.2 and ball indentation 
hardness (injection molding, 358 N, in accordance with DIN 53456) 75 
N/mm.sup.2. 
EXAMPLE 24 
Example 23 was repeated but the metallocene mixture comprised 6.3 mg of 
rac-phenyl(methyl)silyl(2-methyl-1-indenyl).sub.2 zirconium dichloride 
(0.012 mmol) and 2.9 mg of rac-dimethylsilyl(1-indenyl).sub.2 zirconium 
dichloride (0.006 mmol). Polymerization was carried out without hydrogen. 
The polymerization was complete after 20 hours. 
18.7 kg of polymer powder were obtained, corresponding to a metallocene 
activity of 101.6 kg of PP/g of metallocene .times.h. 
VN=202 cm.sup.3 /g; M.sub.w =296,000 g/mol; M.sub.w /M.sub.n =7.9 
II=96.4%; MFI (230/5)=39 g/10 min; m.p.: 148.degree. C. 
The product had the following mechanical data: 
Modulus of elasticity in tension (in accordance with DIN 5347-Z) 1,280 
N/mm.sup.2 ; notched impact strength (a.sub.n in accordance with DIN 
53453) 3 mJ/mm.sup.2 at 23.degree. C.; Izod impact strength (in accordance 
with ISO 180/1 C) 65 mJ/mm.sup.2 at 23.degree. C. and 11 mJ/mm.sup.2 at 
-30.degree. C.; Izod notched impact strength (according to ISO 180/1 A) 3 
mJ/mm.sup.2 at 23.degree. C. and 2 mJ/mm.sup.2 at -30.degree. C.; ball 
indentation hardness 77 N/mm.sup.2 (pressing, conditioned, 358 N) and 71 
N/mm.sup.2 (injection molding, 358 N, in accordance with DIN 53 456).