Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymers from only ethylenic monomers or processes of...
Reexamination Certificate
2000-01-14
2003-03-18
Wu, David W. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Polymers from only ethylenic monomers or processes of...
C526S127000, C526S160000, C502S111000, C502S117000, C502S132000
Reexamination Certificate
active
06534607
ABSTRACT:
The present invention relates to catalysts for the polymerization of olefins, obtained from cyclopentadienyl compounds, organometallic aluminium compounds and water. Homogeneous catalyst systems for the polymerization of olefins are known which comprise a metallocene and the product of the reaction between water and an aluminium alkyl, where the alkyl is other than methyl.
In European Patent Application EP 384 171, catalysts are described which are suitable for the polymerization of olefins and comprise the product of the reaction between:
(A) a metallocene compound of the general formula:
(C
5
R′
n
)
m
R″
p
(C
5
R′
n
)MX
3−m
where (C
5
R′
n
) is a cyclopentadienyl group in which R′ is hydrogen, an alkyl, alkenyl, aryl, alkylaryl or arylalkyl radicals having from 1 to 20 C atoms or a group CR
2
SiR
3
or a group SiR
3
with R being defined as for R′, or two (or four) substituents R′ of one and the same cyclopentadienyl group form one (or two) rings having from 4 to 6 C atoms, R″ is a divalent radical selected from an optionally substituted alkylene group having from 1 to 8 C atoms, an SiR
2
, PR or NR group with R being defined as for R′, which forms a bridge link between two cyclopentadienyl groups, X is hydrogen, halogen, —OMX(C
5
R′
n
)
2
, —OH or —OR with R being defined as for R′, or a hydrocarbon radical having the meaning of R′, M is a transition metal of valency 3 or 4, selected from Ti, Zr or Hf, p is 0 or 1, m is 0, 1 or 2, and, if m=0, p=0 and, if p=0, at least one radical R′ is other than hydrogen, n=4, if p=1, and n=5, if p=0; and
(B) an alumoxane of the formula:
in which R
1
, R
2
, R
3
and R
4
can generically be alkyl, alkenyl or alkylaryl radicals having 2-20 carbon atoms.
The alumoxanes (B) can be prepared by reacting the corresponding trialkylaluminium with water in a 2:1 molar ratio. In the embodiment examples, alumoxanes are used in which R
1
, R
2
1
R
3
and R
4
are ethyl, isobutyl or 2-methylpentyl groups.
European Patent Application EP 575 875 describes homogeneous catalyst systems for the polymerization of olefins, obtained by contacting the following components:
(A) a cyclopentadienyl compound of the general formula:
(C
5
R
1
x−m
H
5−x
)R
2
m
(C
5
R
1
y−m
H
5−y
)
n
MQ
3−n
in which M is Ti, Zr or Hf, C
5
R
1
x−m
H
5−x
and C
5
R
1
y−m
H
5−y
are cyclopentadiene rings substituted in the same way or different ways, the substituents R
1
which can be identical or different are alkyl, alkenyl, aryl, alkylaryl or arylalkyl radicals which have from 1 to 20 carbon atoms and can also contain Si or Ge atoms, or are Si(CH
3
)
3
groups, or also two or four substituents R
1
of one and the same cyclopentadienyl group can form one or two rings having from 4 to 6 carbon atoms, R
2
is a group forming a bridge link between the two cyclopentadiene rings and is selected from CR
3
2
, C
2
R
3
4
, SiR
3
2
, Si
2
R
3
4
, GeR
3
2
, Ge
2
R
3
4
, R
3
2
, SiCR
3
2
, NR
1
or PR
1
, with the substituents R
3
which can be identical or different being R
1
or hydrogen, or also two or four substituents R
3
can form one or two rings having from 3 to 6 carbon atoms, the substituents Q which can be identical or different are halogen, hydrogen, OH, SH, R
1
, OR
1
, SR
1
, NR
1
2
or PR
1
2
, m can be 0 or 1, n can be 0 or 1, being 1 if m=1, x is an integer between (m+1) and 5, and y is an integer between m and 5;
(B) an organometallic aluminium compound of the general formula AlR
3
3−z
H
z
, in which the substituents R
3
which can be identical or different are alkyl, alkenyl or alkylaryl radicals which have from 1 to 10 carbon atoms and can also contain Si or Ge atoms, with the proviso that at least one the substituents R
3
is other than a linear alkyl group, and z is 0 or 1; and
(C) water.
The molar ratio between the organometallic aluminium compound and the water is between 1:1 and 100:1. In the embodiment examples, the organometallic aluminium compounds used are only triisobutylaluminium and triisohexylaluminium.
In Italian Patent Application No. MI/94A/1516, homogeneous catalyst systems for the polymerization of olefins are described which possess an activity improved over those exemplified in the abovementioned patent application EP 575 875, which systems comprise the product obtained by contacting the following components:
(A) a cyclopentadienyl compound of the formula:
(C
5
R
1
x−m
H
5−x
)R
2
m
(C
5
R
1
y−m
H
5−y
)
n
MQ
3−n
in which M is Ti, Zr or Hf; C
5
R
1
x−m
H
5−x
and C
5
R
1
y−m
H
5−y
are cyclopentadiene rings substituted in the same way or different ways, the substituents R
1
which can be identical or different are alkyl, alkenyl, aryl, alkylaryl or arylalkyl radicals which have from 1 to 20 carbon atoms and can also contain Si or Ge atoms, or are Si(CH
3
)
3
groups, or also two or four substituents R
1
of one and the same cyclopentadienyl group can form one or two rings having from 4 to 6 carbon atoms, R
2
is a group forming a bridge link between the two cyclopentadiene rings and is selected from CR
3
2
, C
2
R
3
4
, SiR
3
2
, Si
2
R
3
4
, GeR
3
2
, Ge
2
R
3
4
, R
3
2
SiCR
3
2
, NR
1
or PR
1
, with the substituents R
3
which can be identical or different being R
1
or hydrogen, or also two or four substituents R
3
can form one or two rings having from 3 to 6 carbon atoms, the substituents Q which can be identical or different are halogen, hydrogen, R
1
, OR
1
, SR
1
, NR
1
2
or PR
1
2
, m can be 0 or 1, n can be 0 or 1, being 1, if m=1, x is an integer between (m+1) and 5 and y is an integer between m and 5;
(B) an organometallic aluminium compound of the formula:
Al—(CH
2
—CR
4
R
5
R
6
)
3−z
H
z
in which R
4
is an alkyl, alkenyl or arylalkyl group having from 1 to 10 carbon atoms, R
5
is an alkyl, alkenyl or alkylaryl group with a branched chain having from 3 to 10 carbon atoms, or R
4
and R
5
are fused together to form a ring having from 4 to 6 carbon atoms, R
6
is hydrogen or an alkyl, alkenyl or arylalkyl group having from 1 to 10 carbon atoms and z is 0 or 1; and
(C) water.
The molar ratio between the organometallic aluminium compound and the water is between 1:1 and 100:1.
The polymerization yields of the catalysts described in the abovementioned patent applications are, albeit relatively high, not altogether satisfactory if the residence times of the reaction mixture in the reactor are short. This is particularly important in industrial polymerization processes, especially in those which operate continuously, where it is very advantageous to operate with short residence times.
It would therefore be desirable to improve the productivity of the abovementioned catalysts at short residence times.
BRIEF DESCRIPTION OF THE INVENTION
A It has now been found, unexpectedly, that catalysts for the polymerization of olefins, of the type of those described in the abovementioned patent applications, obtained from particular mixtures of organometallic aluminium compounds, show superior activities at short residence times than the corresponding catalysts obtained from the individual components of the abovementioned mixtures of aluminium compounds.
REFERENCES:
patent: 5006500 (1991-04-01), Chang
patent: 5204419 (1993-04-01), Tsutsui et al.
patent: 6191240 (2001-02-01), Galimberti
Basell Poliolefine Italia S.p.A.
Bryan Cave LLP
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