Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymers from only ethylenic monomers or processes of...
Reexamination Certificate
2000-08-16
2002-02-26
Wilson, Donald R. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Polymers from only ethylenic monomers or processes of...
C526S127000, C526S128000, C526S129000, C502S153000, C502S154000, C502S155000
Reexamination Certificate
active
06350830
ABSTRACT:
The present invention relates to catalyst systems, a process for preparing them and their use in the polymerization of olefins.
Processes for preparing polyolefins with the aid of soluble, homogeneous catalyst systems comprising a transition metal component of the metallocene type and a cocatalyst component such as an aluminoxane, a Lewis acid or an ionic compound are known. These catalysts have a high activity and give polymers and copolymers having a narrow molar mass distribution.
In polymerization processes using soluble, homogeneous catalyst systems, heavy deposits are formed on reactor walls and stirrer if the polymer is obtained as a solid. These deposits are formed by agglomeration of the polymer particles whenever metallocene and/or cocatalyst are present in dissolved form in the suspension. Such deposits in the reactor systems have to be removed regularly since they rapidly reach considerable thicknesses, have a high strength and prevent heat exchange to the cooling medium. Such homogeneous catalyst systems cannot be used industrially in the modern polymerization processes carried out in the liquid monomer or in the gas phase.
To avoid deposit formation in the reactor, catalyst systems in which the metallocene and/or the aluminum compound serving as cocatalyst are fixed to an inorganic support material have been proposed.
EP-A-0,576,970 discloses metallocenes and corresponding supported catalyst systems.
Highly active, supported catalyst systems for preparing industrially important polyolefins having a high tacticity and a high melting point, in particular polypropylenes, comprise ansa-metallocenes in racemic or pseudoracemic form and are known, for example, from EP-A-0,530,647; EP-A-0,576,970 and EP-A-0,653,433.
The synthesis of ansa-metallocenes gives them as isomer mixtures (rac form and meso form or pseudo-rac/pseudo-meso form), so that an additional and costly process step for separating rac and meso form (or the pseudo forms) is necessary. A definition of the terms rac and meso form may be found in Brinzinger et al., Journal of Organometallic Chemistry, 232 (1982) page 233, and Schlögl, Top. Stereochem., 1 (1967) page 39 ff.
It is thus an object of the invention to find an inexpensive, highly active catalyst system for preparing polyolefins having a high tacticity and a high melting point, in particular polypropylenes, and also a simple and economical process for preparing such a catalyst system, which requires no additional separation of rac and meso forms of the metallocene components obtained.
It has now surprisingly been found that the object of the invention is achieved by a supported catalyst system comprising at least one specifically substituted metallocene as rac/meso isomer mixture, at least one cocatalyst, at least one passivated support and, if desired, at least one further additive component.
The present invention provides a catalyst system comprising
a) at least one support,
b) at least one cocatalyst,
c) an rac/meso isomer mixture of at least one metallocene of the formula (I):
where
R
1
and R
2
are identical or different and are each a hydrogen atom, a C
1
-C
20
-hydrocarbon group such as a C
1
-C
20
-alkyl group, preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, pentyl and hexyl, a C
6
-C
14
-aryl group, a C
2
-C
20
-alkenyl group, with the restriction that R
1
is not methyl when R
2
is hydrogen,
M
1
is a transition metal of group 4, 5 or 6 of the Periodic Table of the Elements, for example titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum or tungsten, preferably titanium, zirconium, hafnium, particularly preferably zirconium,
A is a bridge of the formula:
or ═BR
3
, AIR
3
, —S—, —SO—, —SO
2
—, ═NR
3
, ═PR
3
, ═P(O)R
3
, o-phenylene, 2,2′-biphenylene, where
M
2
is carbon, silicon, germanium, tin, nitrogen or phosphorus, preferably carbon, silicon or germanium, in particular carbon or silicon,
o is 1, 2, 3 or 4, preferably 1 or 2,
R
3
and R
4
are identical or different and are each, independently of one another, a hydrogen atom, halogen, a C
1
-C
20
-group such as (C
1
-C
20
)-alkyl, in particular a methyl group, (C
6
-C
14
)-aryl, in particular a phenyl or naphthyl group, (C
1
-C
10
)-alkoxy, (C
2
-C
10
)-alkenyl, (C
7
-C
20
)-arylalkyl, (C
7
-C
20
)-alkylaryl, (C
6
-C
10
)-aryloxy, (C
1
-C
10
)-fluoroalkyl, (C
6
-C
10
)-haloaryl, (C
2
-C
10
)-alkynyl, (C
3
-C
20
)-alkylsilyl such as trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, (C
3
-C
20
)-arylsilyl such as triphenylsilyl, or (C
3
-C
20
)-alkylarylsilyl such as dimethylphenylsilyl, diphenylsilyl or diphenyl-tert-butylsilyl or R
3
and R
4
may together form a monocyclic or polycyclic ring system, and
A is preferably dimethylsilanediyl, dimethylgermanediyl, ethylidene, methylethylidene, 1,1-dimethylethylidene, 1,2-dimethylethylidene, tetramethylethylidene, isopropylidene, methyl-phenylmethylidene, diphenylmethylidene, particularly preferably dimethylsilanediyl, dimethylgermanediyl or ethylidene,
X are identical or different and are each a hydrogen atom, a halogen atom, such as fluorine, chlorine, bromine or iodine, a hydroxyl group, a C
1
-C
10
-alkyl group such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, hexyl, cyclohexyl, a C
6
-C
15
-aryl group such as phenyl, naphthyl, a C
1
-C
10
-alkoxy group such as methoxy, ethoxy, tert-butoxy, a C
6
-C
15
-aryloxy group, a benzyl group, an NR
5
2
group, where R
5
are identical or different and are each a C
1
-C
10
-alkyl group, in particular methyl and/or ethyl, a C
6
-C
15
-aryl group, a (CH
3
)
3
Si group, preferably a chlorine atom, a fluorine atom, a methyl group, a benzyl group, an Nme
2
group, particularly preferably a chlorine atom or a methyl group,
where the ratio of rac isomer to meso isomer of the metallocene of the formula (I) in the catalyst system of the invention is from 1:10 to 2:1, preferably from 1:2 to 3:2.
The metallocene of the formula (I) is preferably one of the compounds:
dimethylsilanediylbis(2-methyl-4-(4′-tert-butylphenyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-4-(4′-tert-butylphenyl)indenyl)hafnium dichloride
dimethylsilanediylbis(2-methyl-4-(4′-tert-butylphenyl)indenyl)titanium dichloride
dimethylsilanediylbis(2-methyl-4-(4′-methylphenyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-4-(4′-ethylphenyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-4-(4′-n-propylphenyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-4-(4′-isopropylphenyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-4-(4′-n-butylphenyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-4-(4′-hexylphenyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-4-(4′-sec-butylphenyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-ethyl-4-phenyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-ethyl-4-(4′-methylphenyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-ethyl-4-(4′-ethylphenyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-ethyl-4-(4′-n-propylphenyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-ethyl-4-(4′-isopropylphenyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-ethyl-4-(4′-n-butylphenyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-ethyl-4-(4′-hexylphenyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-ethyl-4-(4′-pentylphenyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-ethyl-4-(4′-cyclohexylphenyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-ethyl-4-(4′-sec-butylphenyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-ethyl-4-(4′-tert-butylphenyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-n-propyl-4-phenyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-n-propyl-4-(4′-methylphenyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-n-propyl-4-(4′-ethylphenyl)indenyl)zirconium dichloride
Bingel Carsten
Fritze Cornelia
Göres Markus
Cheung William K
Keil & Weinkauf
Tagor GmbH
Wilson Donald R.
LandOfFree
Catalyst system, method for the production thereof and its... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Catalyst system, method for the production thereof and its..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Catalyst system, method for the production thereof and its... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2970500