U.S. patent number RE39,156 [Application Number 09/488,037] was granted by the patent office on 2006-07-04 for process for the preparation of polyolefins.
This patent grant is currently assigned to Basell Polyolefine GmbH. Invention is credited to Martin Antberg, Bernd Bachmann, Volker Dolle, Frank Kuber, Jurgen Rohrmann, Walter Spaleck, Andreas Winter.
United States Patent |
RE39,156 |
Winter , et al. |
July 4, 2006 |
Process for the preparation of polyolefins
Abstract
A process for the preparation of an olefin polymer by
polymerization or copolymerization of an olefin of the formula
R.sup.a--CH.dbd.CH--R.sup.b, in which R.sup.a and R.sup.b are
identical or different and are a hydrogen atom or a hydrocarbon
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 formed from a metallocene in
the meso-form or a meso:rac mixture, with meso:rac>1:99, as
transition-metal compound and a cocatalyst, wherein the metallocene
is a compound of the formula I, ##STR00001## in which M.sup.1 is Zr
or Hf, R.sup.1 and R.sup.2 are identical or different and are
methyl or chlorine, R.sup.3 and R.sup.6 are identical or different
and are methyl, isopropyl, phenyl, ethyl or trifluoromethyl,
R.sup.4 and R.sup.5 are hydrogen or as defined for R.sup.3 and
R.sup.6, or R.sup.4 forms an aliphatic or aromatic ring with
R.sup.6, or adjacent radicals R.sup.4 form a ring of this type, and
R.sup.7 is a ##STR00002## radical, and m plus n is zero or 1.
Inventors: |
Winter; Andreas (Glashutten,
DE), Antberg; Martin (Hofheim am Taunus,
DE), Bachmann; Bernd (Eppstein/Ts, DE),
Dolle; Volker (Kelkheim, DE), Kuber; Frank
(Oberusel, DE), Rohrmann; Jurgen (Liederbach,
DE), Spaleck; Walter (Liederbach, DE) |
Assignee: |
Basell Polyolefine GmbH
(DE)
|
Family
ID: |
27204094 |
Appl.
No.: |
09/488,037 |
Filed: |
January 19, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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08107187 |
Aug 16, 1993 |
5672668 |
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Reissue of: |
08484457 |
Jun 7, 1995 |
05693836 |
Dec 2, 1997 |
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Foreign Application Priority Data
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Aug 15, 1992 [DE] |
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P 42 27 049 |
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Current U.S.
Class: |
556/11; 502/103;
502/117; 526/127; 526/160; 526/943; 556/22; 556/38; 556/43; 556/53;
556/58 |
Current CPC
Class: |
C07F
17/00 (20130101); C08F 10/00 (20130101); C08F
297/083 (20130101); C08F 10/00 (20130101); C08F
4/63927 (20130101); C08F 4/63912 (20130101); C08F
4/63916 (20130101); C08F 4/63927 (20130101); C08F
110/06 (20130101); C08F 110/06 (20130101); C08F
2500/15 (20130101); C08F 2500/03 (20130101); C08F
2500/17 (20130101); C08F 2500/12 (20130101) |
Current International
Class: |
C07F
17/00 (20060101); B01J 31/00 (20060101); C08F
4/642 (20060101) |
Field of
Search: |
;556/11,22,38,43,53,58
;526/127,160,943 ;502/103,117 |
References Cited
[Referenced By]
U.S. Patent Documents
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Primary Examiner: Nazario-Gonzalez; Porfirio
Attorney, Agent or Firm: Connolly Bove Lodge & Hutz
Parent Case Text
This is a divisional of copending application Ser. No. 08/107,187
filed on Aug. 16, 1993.
Claims
What is claimed is:
1. A compound of the formula I in its pure meso-form or as a
meso:rac>1:99 mixture, ##STR00011## in which M.sup.1 is a metal
from group IVb, Vb or VIb of the Periodic Table, 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, the radicals R.sup.4 and R.sup.5 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, which may be halogenated, or an
--NR.sup.10.sub.2, --SR.sup.10, --OSiR.sup.10.sub.3,
--SiR.sup.10.sub.3 or --PR.sup.10.sub.2 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.3 and R.sup.6 are identical or
different and are as defined as for R.sup.4, with the proviso that
R.sup.3 and R.sup.6 are not hydrogen, .[.or two or more of the
radicals R.sup.3 to R.sup.6, together with the atoms connecting
them, form a ring system,.]. ##STR00012## .[.>BR.sup.11,
>AlR.sup.11, --Ge--, --Sn--, --O--, --S--, >SO, >SO.sub.2,
>NR.sup.11, >CO, >PR.sup.11 or >P(O)R.sup.11,.]. where
R.sup.11 .[., R.sup.12 and R.sup.13 are identical or.]. .Iadd.and
R.sup.12 are .Iaddend.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, .Iadd.R.sup.13 is 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,.Iaddend. or R.sup.11
and R.sup.12 or R.sup.11 and R.sup.13, in each case together with
the atoms connecting them, form a ring, M.sup.2 is silicon,
germanium or tin, R.sup.8 and R.sup.9 are identical or different
and are as defined for R.sup.11, and m and n are identical or
different and are zero, 1 or 2, where m plus n is zero, 1 or 2.
2. A compound as claimed in claim 1, wherein, in the formula I,
M.sup.1 is Zr or Hf, R.sup.1 and R.sup.2 are identical or different
and are methyl or chlorine, R.sup.3 and R.sup.6 are identical or
different and are methyl, isopropyl, phenyl, ethyl or
trifluoromethyl, R.sup.4 and R.sup.5 are hydrogen or as defined for
R.sup.3 and R.sup.6, .[.or R.sup.4 forms an aliphatic or aromatic
ring with R.sup.6, or adjacent radicals R.sup.4 form an aliphatic
or aromatic ring, and.]. R.sup.7 is a ##STR00013## radical, and m
plus n are zero or 1.
3. A compound .[.as claimed in claim 1, wherein the compound of the
formula I is Me.sub.2Si(2,4-dimethyl-1-indenyl).sub.2ZrCl.sub.2,
Me.sub.2Si(2-methyl-4-isopropyl-1-indenyl).sub.2ZrCl.sub.2,
Me.sub.2Si(2-ethyl-4-methyl-1-indenyl).sub.2ZrCl.sub.2, Ph(Me)
Si(2-methyl-4-isopropyl-1-indenyl).sub.2ZrCl.sub.2,
Me.sub.2Si(2-methyl-4,5-benzoindenyl).sub.2ZrCl.sub.2,.].
.Iadd.selected from the group consisting of
.Iaddend.Me.sub.2Si(2,4,6-trimethyl-1-indenyl).sub.2ZrCl.sub.2,
Me.sub.2Si(2-methyl-4,6-diisopropyl-1-indenyl).sub.2ZrCl.sub.2,
.[.Me.sub.2Si(2-methyl-.alpha.-acenaphth-indenyl).sub.2ZrCl.sub.2,.].
.Iadd.or
.Iaddend.Me.sub.2Si(2-methyl-4-phenyl-1-indenyl).sub.2ZrCl.sub.2- ,
ethylene(2,4,6-trimethyl-1-indenyl).sub.2ZrCl.sub.2,
.[.ethylene(2-methyl-4,5-benzoindenyl).sub.2ZrCl.sub.2,
methylethylene(2-methyl-.alpha.-acenaphthindenyl).sub.2ZrCl.sub.2
or Ph(Me)Si(2-methyl-.alpha.-acenaphthindenyl).sub.2ZrCl.sub.2.]. .
Description
For the preparation of highly isotactic polyolefins by means of
stereospecific racemic metallocene/cocatalyst systems, the highest
possible isotacticity is desired. This means that very
stereoselective racemic metallocene types are employed which are
able to build up polymer chains having very few construction
faults. The consequence of this is that products having high
crystallinity, high melting point and thus also high hardness and
excellent modulus of elasticity in flexing are obtained as
desired.
However, it is disadvantageous that these polymers are difficult to
process, and in particular problems occur during extrusion,
injection molding and thermoforming. Admixing of flow improvers and
other modifying components could help here, but results in the good
product properties, such as, for example, the high hardness, being
drastically reduced. In addition, tackiness and fogging also occur.
The object was thus to improve the processing properties of highly
isotactic polyolefins of this type without in this way impairing
the good properties of the moldings produced therefrom.
Surprisingly, we have found that if rac/meso mixtures of certain
metallocenes are used, the processing problems can be eliminated
without the abovementioned good product properties being lost.
In addition, the use of these specific metallocenes in their pure
meso-form makes it possible to prepare high-molecular-weight
atactic polyolefins which can be homogeneously admixed, as
additives, with other polyolefins.
This was not possible with the low-molecular weight polyolefins
accessible hitherto due to the large differences in viscosity
between the polyolefin matrix and the atactic component.
Such admixtures improve polyolefin moldings with respect to their
surface gloss, their impact strength and their transparency. In
addition, the processing properties of such polyolefins are
likewise improved by admixing the high-molecular-weight atactic
polyolefin. Likewise, tackiness and fogging do not occur.
Homogeneous miscibility of the atactic component is so important
because only with a homogeneous material can a usable molding with
a good surface and long service life be produced and only in the
case of homogeneous distribution do the qualities of the atactic
component come out in full.
The invention thus relates to the preparation of polyolefins which
1) are atactic, i.e. have an isotactic index of .ltoreq.60%, and
are high-molecular, i.e. have a viscosity index of >80
cm.sup.3/g and a molecular weight M.sub.w of >100,000 g/mol with
a polydispersity M.sub.w/M.sub.n of 4.0, or 2) comprise at least
two types of polyolefin chains, namely a) a maximum of 99% by
weight, preferably a maximum of 98% by weight, of the polymer
chains in the polyolefin as a whole comprise .alpha.-olefin units
linked in a highly isotactic manner, with an isotactic index of
>90% and a polydispersity of .ltoreq.4.0, and b) at least 1% by
weight, preferably at least 2% by weight, of the polymer chains in
the polyolefin as a whole comprise atactic polyolefins of the type
described under 1).
Polyolefins which conform to the description under 2) can either be
prepared directly in the polymerization or are prepared by
melt-mixing in an extruder or compounder.
The invention thus relates to a process for the preparation of an
olefin polymer by polymerization or copolymerization of an olefin
of the formula R.sup.a--CH.dbd.CH--R.sup.b, in which R.sup.a and
R.sup.b are identical or different and are a hydrogen atom or a
hydrocarbon 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 formed from a
metallocene as transition-metal compound and a cocatalyst, wherein
the metallocene is a compound of the formula I which is used in the
pure meso-form for the preparation of polyolefins of type 1 and
used in a meso:rac ratio of greater than 1:99, preferably greater
than 2:98, for the preparation of type 2 polyolefins, ##STR00003##
in which M.sup.1 is a metal from group IVb, Vb or VIb of the
Periodic Table, 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, the
radicals R.sup.4 and R.sup.5 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, which may
be halogenated, and an --NR.sup.10.sub.2, --SR.sup.10,
--OSiR.sup.10.sub.3, --SiR.sup.10.sub.3 or --PR.sup.10.sub.2
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.3 and R.sup.6 are identical or different and are as defined
as for R.sup.4, with the proviso that R.sup.3 and R.sup.6 are not
hydrogen, or two or more of the radicals R.sup.3 to R.sup.6,
together with the atoms connecting them, form a ring system,
##STR00004## .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-fluoroalkyl 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, in each case together with the
atoms connecting them, form a ring, M.sup.2 is silicon, germanium
or tin, R.sup.8 and R.sup.9 are identical or different and are as
defined for R.sup.11, 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)
means fluorine, chlorine, bromine or iodine, preferably fluorine or
chlorine.
The substitutents R.sup.3, R.sup.4, R.sup.5 and R.sup.6 may be
different in spite of the same indexing.
The catalyst to be used for the process according to the invention
comprises a cocatalyst and a metallocene of the formula I.
In the formula I, M.sup.1 is a metal from group IVb, Vb or VIb of
the Periodic Table, for example titanium, zirconium, hafnium,
vanadium, niobium, tantalum, chromium, molybdenum or tungsten,
preferably zirconium, hafnium or titanium.
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.7-C.sub.40-, preferably a C.sub.7-C.sub.12-alkylaryl group, a
C.sub.8-C.sub.40-, preferably a C.sub.8-C.sub.12-arylalkenyl group,
or a halogen atom, preferably chlorine.
The radicals R.sup.4 and R.sup.5 are identical or different and are
a hydrogen atom, a halogen atom, preferably a 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 a
C.sub.6-C.sub.9-aryl group, which may be halogenated, an
--NR.sup.10.sub.2, --SR.sup.10, --OSiR.sup.10.sub.3,
--SiR.sup.10.sub.3 or --PR.sup.10.sub.2 radical, in which R.sup.10
is a halogen atom, preferably a chlorine atom, or a
C.sub.1-C.sub.10-, preferably a 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.4
and R.sup.5 are particularly preferably hydrogen,
C.sub.1-C.sub.4-alkyl or C.sub.6-C.sub.9-aryl.
R.sup.3 and R.sup.6 are identical or different and are defined for
R.sup.4, with the proviso that R.sup.3 and R.sup.6 must not be
hydrogen. R.sup.3 and R.sup.6 are preferably
(C.sub.1-C.sub.4)-alkyl or C.sub.6-C.sub.9-aryl, both of which may
be halogenated, such as methyl, ethyl, propyl, isopropyl, butyl,
isobutyl, trifluoromethyl, phenyl, tolyl or mesityl, in particular
methyl, isopropyl or phenyl.
Two or more of the radicals R.sup.3 to R.sup.6 may alternatively,
together with the atoms connecting them, form an aromatic or
aliphatic ring system. Adjacent radicals, in particular R.sup.4 and
R.sup.6, together preferably form a ring. ##STR00005##
.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 and are a hydrogen atom, a halogen atom, a
C.sub.1-C.sub.10-, preferably C.sub.1-C.sub.4-alkyl group, in
particular a methyl group, a C.sub.1-C.sub.10-fluoroalkyl group,
preferably a 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 a pentafluorophenyl group, a C.sub.1-C.sub.10-,
preferably a C.sub.1-C.sub.4-alkoxy group, in particular a methoxy
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.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, in each
case together with the atoms connecting them, form a ring.
M.sup.2 is silicon, germanium or tin, preferably silicon or
germanium.
R.sup.7 is preferably .dbd.CR.sup.11R.sup.12,
.dbd.SiR.sup.11R.sup.12, .dbd.GeR.sup.11R.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.
Particularly preferred metallocenes are thus the compounds of the
formulae A and B ##STR00006## where
M.sup.1 is Zr or Hf; R.sup.1 and R.sup.2 are methyl or chlorine;
R.sup.3 and R.sup.6 are methyl, isopropyl, phenyl, ethyl or
trifluoromethyl; R.sup.4 and R.sup.5 are hydrogen or as defined for
R.sup.3 and R.sup.6, or R.sup.4 can form an aliphatic or aromatic
ring with R.sup.6; the same also applies to adjacent radicals
R.sup.4; and R.sup.8, R.sup.9, R.sup.11 and R.sup.12 are as defined
above, in particular the compounds I listed in the working
examples.
This means that the indenyl radicals of the compounds I are
substituted, in particular, in the 2,4-position, in the
2,4,6-position, in the 2,4,5-position or in the 2,4,5,6-position,
and the radicals in the 3- and 7-positions are preferably
hydrogen.
Nomenclature: ##STR00007##
The metallocenes described above can be prepared by the following
reaction scheme, which is known from the literature:
##STR00008##
The compounds are formed from the synthesis as rac/meso mixtures.
The meso or rac form can be increased in concentration by
fractional crystallization, for example in a hydrocarbon. This
procedure is known and is part of the prior art.
The cocatalyst used according to the invention is preferably an
aluminoxane of the formula (II) ##STR00009## for the linear type
and/or of the formula (III) ##STR00010## for the cyclic type,
where, in the formulae (II) and (III), the radicals R.sup.14 may be
identical or different and are a C.sub.1-C.sub.6-alkyl group, a
C.sub.6-C.sub.18-aryl group, benzyl or hydrogen, and p is an
integer from 2 to 50, preferably from 10 to 35.
The radicals R.sup.14 are preferably identical and are preferably
methyl, isobutyl, phenyl or benzyl, particularly preferably
methyl.
If the radicals R.sup.14 are different, they are preferably methyl
and hydrogen or alternatively methyl and isobutyl, where hydrogen
and isobutyl are preferably present to the extent of 0.01-40%
(number of radicals R.sup.14).
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 (in gas, solid, liquid or bonded form--for example as
water of crystallization) in an inert solvent (such as, for
example, toluene). In order to prepare an aluminoxane containing
different alkyl groups R.sup.14 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.
Regardless of the preparation method, all the aluminoxane solutions
have in common a varying content of unreacted aluminum starting
compound, in free form or as an adduct.
It is possible to preactivate the metallocene by means of an
aluminoxane of the formula (II) and/or (III) before use in the
polymerization reaction. This significantly increases the
polymerization activity and improves the grain morphology.
The preactivation of the transition-metal compound is carried out
in solution. The metallocene is preferably dissolved in a solution
of the aluminoxane in an inert hydrocarbon. Suitable inert
hydrocarbons are aliphatic and aromatic hydrocarbons. Toluene 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 solution as a
whole. The metallocene can be employed in the same concentration,
but is preferably employed in an amount of from 10.sup.-4 to 1 mol
per mol of aluminoxane. The preactivation time is from 5 minutes to
60 hours, preferably from 5 to 60 minutes. The reaction is carried
out at a temperature of from -78.degree. C. to 100.degree. C.,
preferably from 0.degree. to 70.degree. C.
The metallocene can 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.
According to the invention, compounds of the formulae
R.sub.xNH.sub.4-xBR'.sub.4, R.sub.xPH.sub.4-xBR'.sub.4,
R.sub.3CBR'.sub.4 or BR'.sub.3 can be used as suitable cocatalysts
instead of or in addition to an aluminoxane. In these formulae, x
is a number from 1 to 4, preferably 3, the radicals R are identical
or different, preferably identical, and are C.sub.1-C.sub.10-alkyl,
or C.sub.6-C.sub.18-aryl or 2 radicals R, together with the atom
connecting them, form a ring, and the radicals R' are identical or
different, preferably identical, and are C.sub.6-C.sub.18-aryl,
which may be substituted by alkyl, haloalkyl or fluorine.
In particular, R is ethyl, propyl, butyl or phenyl, and R' is
phenyl, pentafluorophenyl, 3,5-bistrifluoromethylphenyl, mesityl,
xylyl or tolyl (cf. EP-A 277 003, EP-A 277 004 and EP-A 426
638).
When the abovementioned cocatalysts are used, the actual (active
polymerization catalyst comprises the product of the reaction of
the metallocene and one of said compounds. For this reason, this
reaction product is preferably prepared first outside the
polymerization reactor in a separate step using a suitable
solvent.
In principle, suitable cocatalysts are according to the invention
any compounds which, due to their Lewis acidity, are able to
convert the neutral metallocene into a cation and stabilize the
latter ("labile coordination"). In addition, the cocatalyst or the
anion formed therefrom should not undergo any further reactions
with the metallocene cation formed (cf. EP-A 427 697).
In order to remove 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 separated off
again.
The polymerization or copolymerization is carried out in 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 30.degree. to
80.degree. C., particularly preferably at from 50.degree. to
80.degree. C. The polymerization or copolymerization is carried out
using olefins of the formula R.sup.a--CH.dbd.CH--R.sup.b. In this
formula, R.sup.a and R.sup.b are identical or different and are a
hydrogen atom or an alkyl radical having 1 to 14 carbon atoms.
However, R.sup.a and R.sup.b, together with the carbon atoms
connecting them, may alternatively form a ring. Examples of such
olefins are ethylene, propylene, 1-butane, 1-hexene,
4-methyl-1-pentene, 1-octene, norbornene and norbonadiene. In
particular, propylene and ethylene are polymerized.
If necessary, hydrogen is added as molecular weight regulator
and/or to increase the activity. The overall pressure in the
polymerization system is 0.5 to 100 bar. The polymerization is
preferably carried out in the industrially particularly relevant
pressure range of from 5 to 64 bar.
The metallocene is 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 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. The other cocatalysts mentioned are
used in approximately equimolar amounts with respect to the
metallocene. 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 process is carried
out in an aliphatic or cycloaliphatic hydrocarbon; examples of such
hydrocarbons which may be mentioned are propane, butane, pentane,
hexane, heptane, isooctane, cyclohexane and methylcyclohexane.
It is also possible to use a benzine 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 as gases or
liquids.
The polymerization can have any desired duration, since the
catalyst system to be used according to the invention only exhibits
a slight drop in polymerization activity as a function of time.
The process according to the invention is distinguished by the fact
that the meso-metallocenes described give atactic polymers of high
molecular weight in the industrially particularly relevant
temperature range between 50.degree. and 80.degree. C. rac/meso
mixtures of the metallocenes according to the invention give
homogeneous polymers with particular good processing properties.
Moldings produced therefrom are distinguished by good surfaces and
high transparency. In addition, high surface hardnesses and good
moduli of elasticity in flexing are characteristics of these
moldings.
The high-molecular-weight atactic component is not tacky, and the
moldings are furthermore distinguished by very good fogging
behavior.
The examples below serve to illustrate the invention in greater
detail.
The following abbreviations are used:
TABLE-US-00001 VI = viscosity index in cm.sup.3/g determined
M.sub.w = weight average molecular weight by gel in g/mol
permeation M.sub.w/M.sub.n = polydispersity chromato- graphy m.p. =
melting point determined by DSC (20.degree. C./min heating/ cooling
rate) II = isotactic index (II = mm + 1/2 mr) determined by
.sup.13C-NMR spectroscopy n.sub.iso = isotactic block length
(n.sub.iso = 1 + 2 mm/mr) n.sub.syn = syndiotactic block length
(n.sub.syn = 1 + 2 n/mr) MFI/(230/5) = melt flow index, measured in
accordance with DIN 53735; in dg/min.
EXAMPLES 1 TO 16
A dry 24 dm.sup.3 reactor was flushed with propylene and filled
with 12 dm.sup.3 of liquid propylene. 35 cm.sup.3 of a toluene
solution of methylaluminoxane (corresponding to 52 mmol of Al, mean
degree of oligomerization p=18) were then added, and the batch was
stirred at 30.degree. C. for 15 minutes. In parallel, 7.5 mg of the
meso-metallocene shown in Table 1 were dissolved in 13.5 cm.sup.3
of a toluene solution of methylaluminoxane (30 mmol of Al) and
preactivated by standing for 15 minutes. The solution was then
introduced into the reactor and heated to 70.degree. C. or
50.degree. C. (Table 1, 10.degree. C./min). The polymerization
duration was 1 hour. The polymerization was terminated by addition
of 20 dm.sup.3 (s.t.p.) of CO.sub.2 gas. The metallocene activities
and the viscosity indices of the atactic polymers obtained are
collated in Table 1. The .sup.13C-NMR analyses gave in all cases
isotactic block lengths n.sub.iso of <4, typically n.sub.iso=2,
and the syndiotactic block length was typically likewise in the
region of 2. The triad distributions mm/mrar were typically about
25:50:25, and the isotactic index (mm+ 1/2 mr) was less than 60%.
The products were therefore undoubtedly typical atactic
polypropylenes. This is also confirmed by the solubility in boiling
heptane or in diethyl ether.
The DSC spectrum showed no defined melting point. T.sub.g
transitions were observed in the range from 0.degree. C. to
-20.degree. C.
TABLE-US-00002 TABLE 1 Activity Polymerization [kg of PP/g of VI
Meso-metallocene temperature [.degree. C.] metallocene .times. h]
[cm.sup.3/g] Ex. Me.sub.2Si(2,4-dimethyl-1-indenyl).sub.2ZrCl.sub.2
50 35.7 125 1
Me.sub.2Si(2-methyl-4-isopropyl-1-indenyl).sub.2ZrCl.sub.2 70 60.4
93 2 Me.sub.2Si(2-ethyl-4-methyl-1-indenyl).sub.2ZrCl.sub.2 70 70.3
101 3 Ph(Me)Si(2-methyl-4-isopropyl-1-indenyl).sub.2ZrCl.sub.2 50
20.6 120 4 Me.sub.2Si(2-methyl-4,5-benzoindenyl).sub.2ZrCl.sub.2 70
200.0 120 5 Me.sub.2Si(2-methyl-4,5-benzoindenyl).sub.2ZrCl.sub.2
50 60.4 150 6 Me.sub.2Si(2,4,6-trimethyl-1-indenyl).sub.2ZrCl.sub.2
50 30.1 163 7
Me.sub.2Si(2-methyl-4,6-diisopropyl-1-indenyl).sub.2ZrCl.sub.2 50
24.5 89 - 8
Me.sub.2Si(2-methyl-.alpha.-acenaphthindenyl).sub.2ZrCl.sub.2 50
49.3 224 - 9
Me.sub.2Si(2-methyl-.alpha.-acenaphthindenyl).sub.2ZrCl.sub.2 70
189.4 140- 10 Me.sub.2Si(2-methyl-4-phenylindenyl).sub.2ZrCl.sub.2
70 64.5 131 11
Me.sub.2Si(2-methyl-4-phenyl-1-indenyl).sub.2ZrCl.sub.2 50 32.5 169
12 Ethylene(2,4,6-trimethyl-1-indenyl).sub.2ZrCl.sub.2 70 145.5 124
13 Ethylene(2-methyl-4,5-benzoindenyl).sub.2ZrCl.sub.2 50 94.9 109
14
Methylethylene(2-methyl-.alpha.-acenaphthindenyl).sub.2ZrCl.sub.2
50 64.3 - 204 15
Ph(Me)Si(2-methyl-.alpha.-acenaphthindenyl).sub.2ZrCl.sub.2 50 69.8
198 16-
EXAMPLES 17 TO 23
Examples 1, 4, 7, 9, 12, 15 and 16 were repeated but the pure
meso-metallocene was replaced by a rac:meso=1:1 mixture.
The polymers obtained were extracted with boiling ether or
dissolved in a hydrocarbon having a boiling range of
140.degree.-170.degree. C. and subjected to fractional
crystallization; the high-molecular-weight atactic component was
separated off and could thus be analyzed separately from the
isotactic residue. The results are collated in Table 2. Products
are non-tacky, and moldings produced therefrom do not exhibit
fogging and have an excellent surface and transparency.
TABLE-US-00003 TABLE 2 Activity Ether-soluble Ether-insoluble
Rac:meso = 1:1 [kg of PP/g of atactic component isotactic component
Ex. metallocene mixture metallocene .times. h] % by weight VI
[cm.sup.3/g] % by weight VI [cm.sup.3/g] 17
Me.sub.2Si(2,4-dimethyl-1- 69.5 25.4 117 74.6 216
indenyl).sub.2ZrCl.sub.2 18 Ph(Me)Si(2-methyl-4- 102.3 12.0 124
88.0 280 isopropyl-1-indenyl).sub.2ZrCl.sub.2 19
Me.sub.2Si(2,4,6-trimethyl-1- 114.0 18.5 152 71.5 245
indenyl).sub.2ZrCl.sub.2 20 Me.sub.2Si(2-methyl-.alpha.- 61.4 44.9
209 53.1 438 acenaphthindenyl).sub.2ZrCl.sub.2 21
Me.sub.2Si(Si(2-methyl-4-phenyl- 334.5 5.5 177 94.5 887
1-indenyl).sub.2ZrCl.sub.2 (5 mg) 22
Methylthylene(2-methyl-.alpha.- 85.2 36.9 199 63.1 365
acenaphthindenyl).sub.2ZrCl.sub.2 23
Ph(Me)Si(2-methyl-.alpha.-acena- 79.1 31.2 205 68.8 465
phthindenyl).sub.2ZrCl.sub.2
EXAMPLES 24 TO 28
Example 5 was repeated, but the pure meso-form of the metallocene
was replaced by rac:meso ratios of 98:2, 95:5, 90:10, 85:15 and
75:25. The results are collated in Table 3. A non-tacky powder is
obtained, and moldings produced therefrom have a good surface, are
non-tacky and do not exhibit fogging. The molding hardness is good,
as is the transparency.
TABLE-US-00004 TABLE 3 Activity Ether-soluble Ether-insoluble [kg
PP/g atactic isotactic Rac: metallo- component component Ex. meso
cene .times. h] % by wt. VI [cm.sup.3/g] % by wt. VI [cm.sup.3/g]
24 98:2 436 0.95 134 99.05 285 25 95:5 410 2.7 119 97.3 276 26
90:10 415 4.3 122 95.7 296 27 85:15 370 7.3 125 92.7 300 28 75:25
347 15.2 130 84.8 280
EXAMPLE 29
Example 24 was repeated using 12 dm.sup.3 (s.t.p.) of hydrogen in
the polymerization system. The polymerization duration was 30
minutes. The metallocene activity was 586 kg of PP/g of
metallocene.times.h. The ether-soluble proportion was 1.1% by
weight, with a VI of 107 cm.sup.3/g, and the ether-insoluble
proportion was 98.9% by weight, with a VI of 151 cm.sup.3/g.
EXAMPLE 30
Example 25 was repeated, but 70 g of ethylene were metered in
continuously during the polymerization. The polymerization duration
was 45 minutes. The metallocene activity was 468 kg of PP/g of
metallocene.times.h, the ethylene content of the copolymer was 3.3%
by weight, and, according to .sup.13C-NMR spectroscopy, the
ethylene was incorporated substantially in an isolated manner
(random compolymer).
EXAMPLE 31
A dry 150 dm.sup.3 reactor was flushed with nitrogen and filled at
20.degree. C. with 80 dm.sup.3 of a benzine cut having the boiling
range from 100.degree. to 120.degree. C. from which the aromatic
components had been removed. The gas space was then flushed with
propylene until free of nitrogen, and 50 l of liquid propylene and
64 cm.sup.3 of a toluene solution of methylaluminoxane (100 mmol of
Al, p=18) were added. The reactor contents were heated to
60.degree. C., and the hydrogen content in the reactor gas space
was adjusted to 0.1% by metering in hydrogen and was kept constant
during the entire polymerization time by further metering (checking
on-line by gas chromatography). 10.7 mg of rac:meso (95:5) of the
metallocene
dimethylsilane-diylbis(2-methyl-4,5-benzoindenyl)zirconium
dichloride were dissolved in 32 cm.sup.3 of a toluene solution of
methyl-aluminoxane (50 mmol) and introduced into the reactor. The
polymerization was carried out in first step for 8 hours at
60.degree. C. In a second step, 2.8 kg of ethylene were added
rapidly at 47.degree. C. and, after polymerization for a further 5
hours at this temperature, the polymerization was completed by
discharging the reactor contents into a 280 l reactor containing
100 l of acetone. The polymer powder was separated off and dried
for 48 hours at 80.degree. C./200 mbar. 21.4 kg of block copolymer
powder were obtained. VI=359 cm.sup.3/g; M.sub.w=402,000 g/mol,
M.sub.2/M.sub.n=4.0; MFI (230/5)=9.3 dg/min. The block copolymer
contained 12.2% by weight of ethylene. Fractionation gave a content
of 31.5% by weight of ethylene/propylene rubber and 3.7% by weight
of atactic polypropylene, with a VI of 117 cm.sup.3/g in the
polymer as a whole.
EXAMPLE 32
The procedure was as in Examples 1-16, but the metallocene was the
compound
meso-Me.sub.2Si(2-methyl-4-(1-naphthyl)-1-indenyl).sub.2ZrCl.sub-
.2. The results are collated in Table 4.
TABLE-US-00005 TABLE 4 Activity Polymerization [kg of PP/g of VI
M.sub.w temperature [.degree. C.] metallocene .times. h]
[cm.sup.3/g] M.sub.w/M.sub.n [g/mol] 70 58.3 205 2.0 249 500 50
31.7 335 2.1 425 500
EXAMPLE 33
The procedure was as in Example 32, but the metallocene was
Ph(Me)Si(2-methyl-4-phenyl-1-indenyl).sub.2ZrCl.sub.2 and was
employed as a 1:1 meso:rac mixture. The results are collated in
Table 5.
TABLE-US-00006 TABLE 5 Activity Polymerization [kg of PP/g of VI
M.sub.w temperature [.degree. C.] metallocene .times. h]
[cm.sup.3/g] M.sub.w/M.sub.n [g/mol] 70 112.5 559 3.5 738 000 50
51.0 1084 3.6 1.35 10.sup.6
Fractionation of the polymer samples by ether extraction gave
contents of atactic polypropylene of 3.6% by weight (polymerization
temperature of 50.degree. C.) and 7.0% by weight (polymerization
temperature of 70.degree. C.). The VI values were 158 and 106
cm.sup.3/g respectively.
The isolated atactic component had an elastomeric consistency and
was completely transparent.
The polymer powder obtained from the polymerization is non-tacky,
and moldings produced therefrom have a good surface, are very
transparent and do not exhibit fogging.
EXAMPLE 34
The process was as in Example 32, but the metallocene used was
rac/meso-Me.sub.2Si(2-methyl-4-phenyl-1-indenyl).sub.2ZrCl.sub.2 in
supported form, with a rac:meso ratio of 1:1. The supported
metallocene was prepared in the following way:
a) Preparation of the supported cocatalyst
The supported cocatalyst was prepared as described in EP 92 107
331.8 in the following way in an explosion-proofed stainless-steel
reactor fitted with a 60 bar pump system, inert-gas supply,
temperature control by jacket cooling and a second cooling circuit
via a heat exchanger in the pump system. The pump system drew the
contents out of the reactor via a connector in the reactor base
into a mixer and back into the reactor through a riser pipe via a
heat exchanger. The mixer was installed in such a way that a
narrowed tube cross-section, where an increased flow rate occurred,
was formed in the feed line, and a thin feed line through which--in
cycles--in each case a defined amount of water under 40 bar of
argon could be fed in ran into its turbulence zone axially and
against the flow direction. The reaction was monitored via a
sampler in the pump circuit. 5 dm.sup.3 of decane were introduced
under inert conditions into the above-described reactor with a
capacity of 16 dm.sup.3. 0.3 dm.sup.3 (=3.1 mol) of
trimethyl-aluminum were added at 25.degree. C. 250 g of silica gel
SD 3216-30 (Grace AG) which had previously been dried at
120.degree. C. in an argon fluidized bed were then metered into the
reactor via a solids funnel and homogeneously distributed with the
aid of the stirrer and the pump system. The total amount of 45.9 g
of water was added to the reactor in portions of 0.1 cm.sup.3 every
15 seconds over the course of 2 hours. The pressure, caused by the
argon and the evolved gases, was kept constant at 10 bar by
pressure-regulation valves. When all the water had been introduced,
the pump system was switched off and the stirring was continued at
25.degree. C. for a further 5 hours. The solvent was removed via a
pressure filter, and the cocatalyst solid was washed with decane
and then dried in vacuo. The isolated solid contains 19.5% by
weight of aluminum. 15 g of this solid (108 mmol of Al) were
suspended in 100 cm.sup.3 of toluene in a stirrable vessel and
cooled to -30.degree. C. At the same time, 200 mg (0.317 mmol) of
rac/meso 1:1 Me.sub.2Si(2-methyl-4-phenyl-indenyl).sub.2ZrCl.sub.2
were dissolved in 75 cm.sup.3 of toluene and added dropwise to the
suspension over the course of 30 minutes. The mixture was slowly
warmed to room temperature with stirring, during which time the
suspension took on a red color. The mixture was subsequently
stirred at 70.degree. C. for 1 hour, cooled to room temperature and
filtered, and the solid was washed 3 times with 100 cm.sup.3 of
toluene in each case and once with 100 cm.sup.3 of hexane. The
hexane-moist filter residue which remained was dried in vacuo,
giving 14.1 g of free-flowing, pink supported catalyst. Analysis
gave a content of 11.9 mg of zirconocene per gram of catalyst. b)
Polymerization 0.7 g of the catalyst prepared under a) were
suspended in 50 cm.sup.3 of a benzine fraction having the boiling
range 100.degree.-120.degree. C. from which the aromatic components
had been removed. In parallel, a dry 24 dm.sup.3 reactor was
flushed first with nitrogen and subsequently with propylene and
filled with 12 dm.sup.3 of liquid propylene and with 1.5 dm.sup.3
of hydrogen. 3 cm.sup.3 of triisobutylaluminum (12 mmol) were then
diluted with 30 ml of hexane and introduced into the reactor, and
the batch was stirred at 30.degree. C. for 15 minutes. The catalyst
suspension was subsequently introduced into the reactor, and the
polymerization system was heated to the polymerization temperature
of 70.degree. C. (10.degree. C./min) and kept at 70.degree. C. for
1 hour by cooling. The polymerization was terminated by addition of
20 mol of isopropanol. The excess monomer was removed as a gas, and
the polymer was dried in vacuo, giving 1.57 kg of polypropylene
powder. Fractionation of the polymer by ether extraction gave an
ether-soluble atactic content of 8.9% by weight (VI=149 cm.sup.3/g)
and an insoluble isotactic content of 91.1% by weight, with a VI of
489 cm.sup.3/g. The powder prepared in this way was non-tacky, and
moldings produced therefrom do not exhibit fogging in the
heat-aging test, and the hardness and transparency of the moldings
are very good.
Comparative Examples 1 to 10
Polymerization were carried out in a manner comparable to the above
examples using 1:1 rac:meso mixtures of metallocenes not according
to the invention at polymerization temperatures of 70.degree. C.
and 30.degree. C. The resultant polymers were likewise subjected to
ether separation in order to characterize the polymer components.
The results are collated in Table 6 and show that in no case could
a polymer according to the invention having a high-molecular-weight
atactic polymer component (ether-soluble component) be prepared.
Products are generally tacky, and the moldings produced therefrom
are soft, have a speckled surface and exhibit considerable
fogging.
TABLE-US-00007 TABLE 6 Polymer data Polymerization temperature
70.degree. C. Polymerization temperature 30.degree. C. Metallocene
VI ether-soluble VI ether-insoluble VI ether-soluble VI
ether-insoluble rac:meso = 1:1 mixture [cm.sup.3/g] [cm.sup.3/g]
[cm.sup.3/g] [cm.sup.3/g] Me.sub.2Si(indenyl).sub.2ZrCl.sub.2 45 42
46 75 Me.sub.2Si(2-methyl-1-indenyl).sub.2ZrCl.sub.2 50 180 56 340
Methylethylene(2-methyl-1- 56 127 59 409 indenyl).sub.2ZrCl.sub.2
Ph(Me)Si(2-methyl-1- 50 202 57 501 indenyl).sub.2ZrCl.sub.2
Me.sub.2Si(2-ethyl-1-indenyl).sub.2ZrCl.sub.2 59 187 61 443
Me.sub.2Si(2,4,5-trimethyl-1-cyclo- 45 50 47 236
pentadienyl).sub.2ZrCl.sub.2 Me.sub.2Si(2,4,5-trimethyl-1-cyclo- 59
175 69 356 pentadienyl).sub.2HfCl.sub.2
Me.sub.2Si(indenyl).sub.2HfCl.sub.2 61 237 63 398
Ethylene(2-methyl-1- 47 85 50 135 indenyl).sub.2ZrCl.sub.2
Me.sub.2Si(2-methyl-4-t-butyl-1- 28 31 35 105
cyclopentadienyl).sub.2ZrCl.sub.2
Comparative Examples 11 to 21
Comparative Examples 1 to 10 were repeated using the pure
meso-forms of the metallocenes used therein. Atactic polypropylene
was obtained, but in no case was a viscosity index VI of >70
cm.sup.3/g obtained. These metallocenes which are not according to
the invention can thus not be used to prepare high-molecular-weight
atactic polypropylene. The products are liquid or at least soft and
highly tacky.
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