U.S. patent application number 13/167997 was filed with the patent office on 2012-12-27 for advanced transition metal catalytic systems in terms of comonomer incorporations and methods for preparing ethylene homopolymers or copolymers of ethylene and a-olefins using the same.
This patent application is currently assigned to SK INNOVATION CO., LTD.. Invention is credited to JONGSOK HAHN, HOSEONG LEE, Hyosun LEE, DONGCHEOL SHIN, ChunJi Wu.
Application Number | 20120329965 13/167997 |
Document ID | / |
Family ID | 47362446 |
Filed Date | 2012-12-27 |
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United States Patent
Application |
20120329965 |
Kind Code |
A1 |
LEE; HOSEONG ; et
al. |
December 27, 2012 |
ADVANCED TRANSITION METAL CATALYTIC SYSTEMS IN TERMS OF COMONOMER
INCORPORATIONS AND METHODS FOR PREPARING ETHYLENE HOMOPOLYMERS OR
COPOLYMERS OF ETHYLENE AND A-OLEFINS USING THE SAME
Abstract
Provided is a homogeneous catalytic system for use in preparing
an ethylene homopolymer or a copolymer of ethylene and
.alpha.-olefin, and more particularly a Group 4 transition metal
compound in which a cyclopentadienyl derivative 3,4-positions of
which are substituted with alkyls and an electron-donating
substituent are crosslinked around a Group 4 transition metal. Also
provided is a method of preparing an ethylene homopolymer or a
copolymer of ethylene and .alpha.-olefin, having high molecular
weight, under high-temperature solution polymerization conditions
using the catalytic system including such a transition metal
compound and a co-catalyst composed of an aluminum compound, a
boron compound or a mixture thereof. The catalyst according to
present invention has high thermal stability and enables the
incorporation of .alpha.-olefin, and is thus effective in preparing
an ethylene homopolymer or a copolymer of ethylene and
.alpha.-olefin, having various properties, in industrial
polymerization processes.
Inventors: |
LEE; HOSEONG; (Seoul,
KR) ; HAHN; JONGSOK; (Daejeon, KR) ; SHIN;
DONGCHEOL; (Daejeon, KR) ; LEE; Hyosun;
(Daegu, KR) ; Wu; ChunJi; (Daegu, KR) |
Assignee: |
SK INNOVATION CO., LTD.
Seoul
KR
|
Family ID: |
47362446 |
Appl. No.: |
13/167997 |
Filed: |
June 24, 2011 |
Current U.S.
Class: |
526/127 ;
502/113; 502/128; 526/126; 556/11 |
Current CPC
Class: |
C08F 4/6592 20130101;
C08F 210/16 20130101; Y10S 526/943 20130101; C07F 17/00 20130101;
C07F 7/28 20130101; C08F 4/65908 20130101; C08F 210/16 20130101;
C08F 4/6592 20130101; C08F 210/14 20130101; C08F 210/14 20130101;
C08F 2500/03 20130101; C08F 2500/04 20130101; C08F 4/65912
20130101; C08F 210/16 20130101 |
Class at
Publication: |
526/127 ;
502/128; 502/113; 556/11; 526/126 |
International
Class: |
C08F 4/6592 20060101
C08F004/6592; C08F 210/08 20060101 C08F210/08; C08F 4/76 20060101
C08F004/76; C08F 210/06 20060101 C08F210/06; C08F 210/02 20060101
C08F210/02; C07F 17/00 20060101 C07F017/00; C08F 210/14 20060101
C08F210/14 |
Claims
1. A transition metal compound represented by Chemical Formula 1
below: ##STR00002## [wherein, M is a Group 4 transition metal of
the periodic table; R.sup.1 and R.sup.2 are a (C1-C7) alkyl group;
D is --O--, --S--, --N(R.sup.5)-- or --P(R.sup.6)--, in which
R.sup.5 and R.sup.6 are independently a hydrogen atom, a (C1-C20)
alkyl group, a (C3-C20) cycloalkyl group, a (C6-C30) aryl group, a
(C6-C30) aryl(C1-C20) alkyl group, a (C1-C20) alkylcarbonyl group,
or a (C3-C20) cycloalkylcarbonyl group; R.sup.3 and R.sup.4 are
independently a hydrogen atom, a (C1-C20) alkyl group, a (C6-C30)
aryl group, a (C6-C30) aryl(C1-C20) alkyl group, a (C1-C20) alkoxy
group, or a (C1-C20) alkyl or (C3-C20) cycloalkyl substituted
siloxy group; X is independently a halogen atom, a (C1-C20) alkyl
group, a (C6-C30) aryl group, a (C6-C30) aryl(C1-C20) alkyl group,
a (C1-C20) alkoxy group, a (C1-C20) alkyl or (C3-C20) cycloalkyl
substituted siloxy group, a (C1-C20) alkyl, (C6-C30) aryl, (C6-C30)
aryl(C1-C20) alkyl or tri(C1-C20) alkylsilyl substituted amino
group, a (C1-C20) alkyl, (C6-C30) aryl, (C6-C30) aryl(C1-C20) alkyl
or tri(C1-C20) alkylsilyl substituted amide group, a (C1-C20)
alkyl, (C6-C30) aryl, (C6-C30) aryl(C1-C20) alkyl or tri(C1-C20)
alkylsilyl substituted phosphine group, or a (C1-C20) alkyl,
(C6-C30) aryl, (C6-C30) aryl(C1-C20) alkyl or tri(C1-C20)
alkylsilyl substituted phosphido group, in which the case where X
is a cyclopentadienyl derivative is excluded; the alkyl group of
R.sup.1 and R.sup.2, the alkyl group, aryl group, arylalkyl group
and alkoxy group of R.sup.3 and R.sup.4, the alkyl group,
cycloalkyl group, aryl group, arylalkyl group, alkylcarbonyl group
and cycloalkylcarbonyl group of R.sup.5 and R.sup.6, the alkyl
group, aryl group, arylalkyl group and alkoxy group of X may be
further substituted with one or more selected from among a (C1-C20)
alkyl group, a (C3-C20) cycloalkyl group, a (C6-C30) aryl group,
and a (C6-C30) aryl(C1-C20) alkyl group; and n is an integer of
1.about.4].
2. The transition metal compound of claim 1, wherein the M is
titanium, zirconium, or hafnium.
3. The transition metal compound of claim 1, wherein the R.sup.1
and R.sup.2 are independently selected from among a methyl group,
an ethyl group, a n-propyl group, an isopropyl group, a n-butyl
group, a sec-butyl group, a tert-butyl group, and a n-pentyl
group.
4. The transition metal compound of claim 1, wherein the R.sup.5
and R.sup.6 are independently selected from among a methyl group,
an ethyl group, a n-propyl group, an isopropyl group, a sec-butyl
group, a tert-butyl group, a cyclohexyl group, a dicyclohexylmethyl
group, an adamantyl group, a phenyl group, a phenylmethyl group, a
methylcarbonyl group, an ethylcarbonyl group, a n-propylcarbonyl
group, an isopropylcarbonyl group, a tert-butylcarbonyl group, and
an adamantylcarbonyl group.
5. A transition metal catalyst composition for preparing an
ethylene homopolymer or a copolymer of ethylene and .alpha.-olefin,
comprising the transition metal compound of claim 1; and a
co-catalyst selected from among an aluminum compound, a boron
compound, and mixtures thereof.
6. The transition metal catalyst composition of claim 5, wherein
the aluminum compound is a co-catalyst comprising one or more
selected from aluminoxane and organic aluminum, and is selected
from among methylaluminoxane, modified methylaluminoxane,
tetraisobutylaluminoxane, trialkylaluminum, dialkylaluminum
chloride, alkylaluminium dichloride, dialkylaluminum hydride and
mixtures thereof; and the boron compound is selected from among
N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate,
triphenylmethyl tetrakis(pentafluorophenyl)borate, and mixtures
thereof.
7. The transition metal catalyst composition of claim 5, wherein as
a ratio of transition metal compound to co-catalyst, a molar ratio
of transition metal (M) to aluminum atom (Al) is
1:50.about.5,000.
8. The transition metal catalyst composition of claim 5, wherein as
a ratio of transition metal compound to co-catalyst, a molar ratio
of transition metal (M) to boron atom (B) to aluminum atom (Al) is
1:0.5.about.5:25.about.500.
9. A method of preparing an ethylene homopolymer or a copolymer of
ethylene and .alpha.-olefin using the transition metal catalyst
composition of claim 5, wherein a comonomer which is polymerized
with ethylene is one or more selected from among propylene,
1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene,
1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-itocene,
and the copolymer of ethylene and .alpha.-olefin has an ethylene
content of 50 wt % or more.
10. The method of claim 9, wherein a pressure of the ethylene in a
reactor is 6.about.150 atom, and a polymerization temperature is
60.about.250.degree. C.
11. The method of claim 9, wherein the copolymer has a weight
average molecular weight of 80,000.about.500,000 and a molecular
weight distribution (Mw/Mn) of 1.5.about.4.1.
12. An ethylene homopolymer or a copolymer of ethylene and
.alpha.-olefin, prepared using the transition metal compound of
claim 1 as a catalyst.
13. An ethylene homopolymer or a copolymer of ethylene and
.alpha.-olefin, prepared using the transition metal catalyst
composition of claim 5.
Description
TECHNICAL FIELD
[0001] The present invention relates to a homogeneous catalytic
system for use in preparing an ethylene homopolymer or a copolymer
of ethylene and .alpha.-olefin, and more particularly to a Group 4
transition metal catalyst in which a cyclopentadienyl derivative
3,4-positions of which are substituted with alkyls and an
electron-donating substituent are crosslinked around the Group 4
transition metal. In addition, the present invention relates to a
catalytic system comprising such a transition metal catalyst and a
co-catalyst including one or more selected from among aluminoxane
and a boron compound and to a method of preparing an ethylene
homopolymer or a copolymer of ethylene and .alpha.-olefin using the
same.
BACKGROUND ART
[0002] Conventional ethylene homopolymers or copolymers with
.alpha.-olefin have been typically prepared using so-called a
Ziegler-Natta catalytic system comprising a titanium or vanadium
compound as a main catalyst and an alkylaluminum compound as a
co-catalyst. Although the Ziegler-Natta catalytic system is highly
active for ethylene polymerization, it has non-uniform active
sites, so that the produced polymer has a wide molecular weight
distribution, and, in particular, the composition distribution is
not uniform in copolymerization of ethylene and .alpha.-olefin.
[0003] Recently, there has been developed a metallocene catalytic
system composed of a metallocene compound of Group 4 transition
metal of the periodic table, such as titanium, zirconium, hafnium,
etc., and a co-catalyst such as methylaluminoxane. Because the
metallocene catalytic system is a homogeneous catalyst having
single active sites, it enables the preparation of polyethylene
having a narrower molecular weight distribution and a more uniform
composition distribution, compared to when using the conventional
Ziegler-Natta catalytic system. For example, EP Patent Application
Publication Nos. 320,762 and 3,726,325, Japanese Patent Laid-open
Publication No. Sho. 63-092621, and Japanese Patent Laid-open
Publication Nos. Hei. 02-84405 and 03-2347 disclose a metallocene
compound such as Cp.sub.2TiCl.sub.2, Cp.sub.2ZrCl.sub.2,
Cp.sub.2ZrMeCl, Cp.sub.2ZrMe.sub.2,
ethylene(IndH.sub.4).sub.2ZrCl.sub.2, etc., which is activated with
a methylaluminoxane co-catalyst, so that ethylene is highly
actively polymerized, thereby preparing polyethylene having a
molecular weight distribution (Mw/Mn) of 1.5.about.2.0. However,
this catalytic system makes it difficult to obtain a
high-molecular-weight polymer. In particular, when this is applied
to solution polymerization at a high temperature of at least
140.degree. C., polymerization activity is drastically decreased
and .beta.-dehydrogenation is predominantly carried out, and thus
such a catalytic system is known to be unsuitable to prepare a
high-molecular-weight polymer having a weight average molecular
weight (Mw) of 100,000 or more.
[0004] U.S. Pat. No. 5,084,534 by Exxon discloses the preparation
of a copolymer having a narrow molecular weight distribution of
1.8.about.3.0 and a uniform composition distribution by
polymerizing ethylene alone or ethylene with 1-hexene or 1-octene
at 150.about.200.degree. C. using a (n-BuCp).sub.2ZrCl.sub.2
catalyst and a methylaluminoxane co-catalyst. In addition, EP
Patent Nos. 0416815 and 0420436, by Dow, disclose a catalyst the
structure of which is geometrically controlled by connecting an
amide group in the form of a ring to a cyclopentadiene ligand, and
which exhibits high catalytic activity upon polymerizing ethylene
alone or ethylene with .alpha.-olefin under slurry polymerization
or solution polymerization conditions and also increases high
reactivity with comonomers, thereby enabling the preparation of a
high-molecular-weight polymer having a uniform composition
distribution. As in the metallocene catalyst, however, the above
catalyst is drastically deteriorated in terms of catalytic
stability and comonomer incorporations in proportion to an increase
in the temperature under high-temperature solution polymerization
conditions of at least 140.degree. C., and economic benefits negate
attributed to high material cost, making it difficult to
industrially use it.
SUMMARY OF THE INVENTION
[0005] Culminating in the present invention, intensive and thorough
research was carried out by the present inventors aiming to solve
the problems encountered in the related art, which resulted in the
finding that a geometrically constrained catalyst in which a
cyclopentadienyl derivative 3,4-positions of which are substituted
with alkyls and an electron-donating substituent are crosslinked
around a Group 4 transition metal is remarkably advanced in terms
of comonomer incorporations, making it suitable to prepare an
ethylene homopolymer or an elastic copolymer of ethylene and
.alpha.-olefin, having high molecular weight and high activity
using solution polymerization at a high temperature of at least
140.degree. C.
[0006] Therefore, an object of the present invention is to provide
a catalyst having single active sites, which may exhibit superior
thermal stability and is advanced in terms of comonomer
incorporations, and a high-temperature solution polymerization
method which enables an ethylene homopolymer or a copolymer of
ethylene and .alpha.-olefin, having various properties, to be
easily prepared from an industrial point of view using such a
catalyst.
[0007] In one aspect to accomplish the above object, the present
invention provides a transition metal compound represented by
Chemical Formula 1 below, in which a cyclopentadiene derivative
3,4-positions of which are substituted with alkyls an
electron-donating substituent are crosslinked around a Group 4
transition metal of the periodic table as a central metal. In
addition, the present invention provides a catalyst composition
comprising the above transition metal compound and a co-catalyst
selected from among an aluminum compound, a boron compound and
mixtures thereof, and a method of preparing an ethylene homopolymer
or a copolymer of ethylene with .alpha.-olefin using the same.
##STR00001##
[0008] [In Chemical Formula 1, M is a Group 4 transition metal of
the periodic table;
[0009] R.sup.1 and R.sup.2 are a (C1-C7) alkyl group;
[0010] D is --O--, --S--, --N(R.sup.5)-- or --P(R.sup.6)--, in
which R.sup.5 and R.sup.6 are independently a hydrogen atom, a
(C1-C20) alkyl group, a (C3-C20) cycloalkyl group, a (C6-C30) aryl
group, a (C6-C30) aryl(C1-C20) alkyl group, a (C1-C20)
alkylcarbonyl group, or a (C3-C20) cycloalkylcarbonyl group;
[0011] R.sup.3 and R.sup.4 are independently a hydrogen atom, a
(C1-C20) alkyl group, a (C6-C30) aryl group, a (C6-C30)
aryl(C1-C20) alkyl group, a (C1-C20) alkoxy group, or a (C1-C20)
alkyl or (C3-C20) cycloalkyl substituted siloxy group;
[0012] X is independently a halogen atom, a (C1-C20) alkyl group, a
(C6-C30) aryl group, a (C6-C30) aryl(C1-C20) alkyl group, a
(C1-C20) alkoxy group, a (C1-C20) alkyl or (C3-C20) cycloalkyl
substituted siloxy group, a (C1-C20) alkyl, (C6-C30) aryl, (C6-C30)
aryl(C1-C20) alkyl or tri(C1-C20) alkylsilyl substituted amino
group, a (C1-C20) alkyl, (C6-C30) aryl, (C6-C30) aryl(C1-C20) alkyl
or tri(C1-C20) alkylsilyl substituted amide group, a (C1-C20)
alkyl, (C6-C30) aryl, (C6-C30) aryl(C1-C20) alkyl or tri(C1-C20)
alkylsilyl substituted phosphine group, or a (C1-C20) alkyl,
(C6-C30) aryl, (C6-C30) aryl(C1-C20) alkyl or tri(C1-C20)
alkylsilyl substituted phosphido group, in which the case where X
is a cyclopentadienyl derivative is excluded;
[0013] the alkyl group of R.sup.1 and R.sup.2, the alkyl group,
aryl group, arylalkyl group and alkoxy group of R.sup.3 and
R.sup.4, the alkyl group, cycloalkyl group, aryl group, arylalkyl
group, alkylcarbonyl group and cycloalkylcarbonyl group of R.sup.5
and R.sup.6, the alkyl group, aryl group, arylalkyl group and
alkoxy group of X may be further substituted with one or more
selected from among a (C1-C20) alkyl group, a (C3-C20) cycloalkyl
group, a (C6-C30) aryl group, and a (C6-C30) aryl(C1-C20) alkyl
group; and
[0014] n is an integer of 1.about.4].
[0015] In another aspect, the present invention provides a
transition metal catalyst composition for preparing an ethylene
homopolymer or a copolymer of ethylene and .alpha.-olefin,
comprising the above transition metal compound and a co-catalyst
selected from among an aluminum compound, a boron compound and
mixtures thereof, and an ethylene homopolymer or a copolymer of
ethylene and .alpha.-olefin using the transition metal compound or
the catalyst composition.
[0016] Below, the present invention is described in more detail.
Specifically, M is preferably titanium, zirconium or hafnium. Also,
R.sup.1 and R.sup.2 which are independently located at
3,4-positions of cyclopentadienyl able to form .eta..sup.5-bond
with M are a (C1-C7) alkyl group, for example, a methyl group, an
ethyl group, a n-propyl group, an isopropyl group, a n-butyl group,
a sec-butyl group, a tert-butyl group, or a n-pentyl group, and
particularly useful is a methyl group.
[0017] Also, R.sup.5 and R.sup.6 are independently a hydrogen atom,
a (C1-C20) alkyl group, a (C3-C20) cycloalkyl group, a (C6-C30)
aryl group, a (C6-C30) aryl(C1-C20) alkyl group, a (C1-C20)
alkylcarbonyl group or a (C3-C20) cycloalkylcarbonyl group, and
more specifically a methyl group, an ethyl group, a n-propyl group,
an isopropyl group, a sec-butyl group, a tert-butyl group, a
cyclohexyl group, a dicyclohexylmethyl group, an adamantyl group, a
phenyl group, a phenylmethyl group, a methylcarbonyl group, an
ethylcarbonyl group, a n-propylcarbonyl group, an isopropylcarbonyl
group, a tert-butylcarbonyl group or an adamantylcarbonyl group.
Particularly useful is a tert-butyl group.
[0018] Also, R.sup.3 and R.sup.4 bound with Si are independently a
hydrogen atom, a (C1-C20) alkyl group, a (C6-C30) aryl group, a
(C6-C30) aryl(C1-C20) alkyl group, a (C1-C20) alkoxy group, or a
(C1-C20) alkyl or (C3-C20) cycloalkyl substituted siloxy group, and
examples of the (C1-C20) alkyl group include a methyl group, an
ethyl group, a n-propyl group, an isopropyl group, a n-butyl group,
a sec-butyl group, a tert-butyl group, a n-pentyl group, a
neopentyl group, an amyl group, a n-hexyl group, a n-octyl group, a
n-decyl group, a n-dodecyl group, a n-pentadecyl group or a
n-eicosyl group, and particularly useful is a methyl group, an
ethyl group, an isopropyl group, a tert-butyl group or an amyl
group; examples of the (C6-C30) aryl group or the (C6-C30)
aryl(C1-C20) alkyl group include a benzyl group, a
(2-methylphenyl)methyl group, a (3-methylphenyl)methyl group, a
(4-methylphenyl)methyl group, a (2,3-dimethylphenyl)methyl group, a
(2,4-dimethylphenyl)methyl group, a (2,5-dimethylphenyl)methyl
group, a (2,6-dimethylphenyl)methyl group, a
(3,4-dimethylphenyl)methyl group, a (4,6-dimethylphenyl)methyl
group, a (2,3,4-trimethylphenyl)methyl group, a
(2,3,5-trimethylphenyl)methyl group, a
(2,3,6-trimethylphenyl)methyl group, a
(3,4,5-trimethylphenyl)methyl group, a
(2,4,6-trimethylphenyl)methyl group, a
(2,3,4,5-tetramethylphenyl)methyl group, a
(2,3,4,6-tetramethylphenyl)methyl group, a
(2,3,5,6-tetramethylphenyl)methyl group, a
(pentamethylphenyl)methyl group, an (ethylphenyl)methyl group, a
(n-propylphenyl)methyl group, an (isopropylphenyl)methyl group, a
(n-butylphenyl)methyl group, a (sec-butylphenyl)methyl group, a
(tert-butylphenyl)methyl group, a (n-pentylphenyl)methyl group, a
(neopentylphenyl)methyl group, a (n-hexylphenyl)methyl group, a
(n-octylphenyl)methyl group, a (n-decylphenyl)methyl group, a
(n-dodecylphenyl)methyl group, a (n-tetradecylphenyl)methyl group,
a naphthylmethyl group or an anthracenylmethyl group, and
particularly useful is benzyl; examples of the (C1-C20) alkoxy
group include a methoxy group, an ethoxy group, a n-propoxy group,
an isopropoxy group, a n-butoxy group, a sec-butoxy group, a
tert-butoxy group, a n-pentoxy group, a neopentoxy group, a
n-hexoxy group, a n-octoxy group, a n-dodecoxy group, a
n-pentadecoxy group, or a n-eicosoxy group, and particularly useful
is a methoxy group, an ethoxy group, an isopropoxy group or a
tert-butoxy group; and examples of the (C1-C20) alkyl or (C3-C20)
cycloalkyl substituted siloxy group include a trimethylsiloxy
group, a triethylsiloxy group, a tri-n-propylsiloxy group, a
triisopropylsiloxy group, a tri-n-butylsiloxy group, a
tri-sec-butylsiloxy group, a tri-tert-butylsiloxy group, a
tri-isobutylsiloxy group, a tert-butyldimethylsiloxy group, a
tri-n-pentylsiloxy group, a tri-n-hexylsiloxy group or a
tricyclohexylsiloxy group, and particularly useful is a
trimethylsiloxy group or a tert-butyldimethylsiloxy group.
[0019] X is independently a halogen atom, a (C1-C20) alkyl group, a
(C6-C30) aryl group, a (C6-C30) aryl(C1-C20) alkyl group, a
(C1-C20) alkoxy group, a (C1-C20) alkyl or (C3-C20) cycloalkyl
substituted siloxy group, a (C1-C20) alkyl, (C6-C30) aryl, (C6-C30)
aryl(C1-C20) alkyl or tri(C1-C20) alkylsilyl substituted amino
group, a (C1-C20) alkyl, (C6-C30) aryl, (C6-C30) aryl(C1-C20) alkyl
or tri(C1-C20) alkylsilyl substituted amide group, a (C1-C20)
alkyl, (C6-C30) aryl, (C6-C30) aryl(C1-C20) alkyl or tri(C1-C20)
alkylsilyl substituted phosphine group, or a (C1-C20) alkyl,
(C6-C30) aryl, (C6-C30) aryl(C1-C20) alkyl or tri(C1-C20)
alkylsilyl substituted phosphido group, wherein the case where X is
a cyclopentadienyl derivative is excluded. Examples of the halogen
atom include fluorine, chlorine, bromine or iodine; examples of the
(C1-C20) alkyl group include a methyl group, an ethyl group, a
n-propyl group, an isopropyl group, a n-butyl group, a sec-butyl
group, a tert-butyl group, a n-pentyl group, a neopentyl group, an
amyl group, a n-hexyl group, a n-octyl group, a n-decyl group, a
n-dodecyl group, a n-pentadecyl group or a n-eicosyl group, and
particularly useful is a methyl group, an ethyl group, an isopropyl
group, a tert-butyl group or an amyl group; examples of the
(C6-C30) aryl(C1-C20) alkyl group include a benzyl group, a
(2-methylphenyl)methyl group, a (3-methylphenyl)methyl group, a
(4-methylphenyl)methyl group, a (2,3-dimethylphenyl)methyl group, a
(2,4-dimethylphenyl)methyl group, a (2,5-dimethylphenyl)methyl
group, a (2,6-dimethylphenyl)methyl group, a
(3,4-dimethylphenyl)methyl group, a (4,6-dimethylphenyl)methyl
group, a (2,3,4-trimethylphenyl)methyl group, a
(2,3,5-trimethylphenyl)methyl group, a
(2,3,6-trimethylphenyl)methyl group, a
(3,4,5-trimethylphenyl)methyl group, a
(2,4,6-trimethylphenyl)methyl group, a
(2,3,4,5-tetramethylphenyl)methyl group, a
(2,3,4,6-tetramethylphenyl)methyl group, a
(2,3,5,6-tetramethylphenyl)methyl group, a
(pentamethylphenyl)methyl group, an (ethylphenyl)methyl group, a
(n-propylphenyl)methyl group, an (isopropylphenyl)methyl group, a
(n-butylphenyl)methyl group, a (sec-butylphenyl)methyl group, a
(tert-butylphenyl)methyl group, a (n-pentylphenyl)methyl group, a
(neopentylphenyl)methyl group, a (n-hexylphenyl)methyl group, a
(n-octylphenyl)methyl group, a (n-decylphenyl)methyl group, a
(n-decylphenyl)methyl group, a (n-tetradecylphenyl)methyl group, a
naphthylmethyl group or an anthracenylmethyl group, and
particularly useful is a benzyl group; examples of the (C1-C20)
alkoxy group include a methoxy group, an ethoxy group, a n-propoxy
group, an isopropoxy group, a n-butoxy group, a sec-butoxy group, a
tert-butoxy group, a n-pentoxy group, a neopentoxy group, a
n-hexoxy group, a n-octoxy group, a n-dodecoxy group, a
n-pentadecoxy group, or a n-eicosoxy group, and particularly useful
is a methoxy group, an ethoxy group, an isopropoxy group or a
tert-butoxy group; examples of the (C1-C20) alkyl or (C3-C20)
cycloalkyl substituted siloxy group include a trimethylsiloxy
group, a triethylsiloxy group, a tri-n-propylsiloxy group, a
triisopropylsiloxy group, a tri-n-butylsiloxy group, a
tri-sec-butylsiloxy group, a tri-tert-butylsiloxy group, a
tri-isobutylsiloxy group, a tert-butyldimethylsiloxy group, a
tri-n-pentylsiloxy group, a tri-n-hexylsiloxy group or a
tricyclohexylsiloxy group, and particularly useful is a
trimethylsiloxy group or a tert-butyldimethylsiloxy group; examples
of the (C1-C20) alkyl, (C6-C30) aryl, (C6-C30) aryl(C1-C20) alkyl
or (C1-C20) alkylsilyl substituted amino group include a
dimethylamino group, a diethylamino group, a di-n-propylamino
group, a diisopropylamino group, a di-n-butylamino group, a
di-sec-butylamino group, a di-tert-butylamino group, a
diisobutylamino group, a tert-butylisopropylamino group, a
di-n-hexylamino group, a di-n-octylamino group, a di-n-decylamino
group, a diphenylamino group, a dibenzylamino group, a
methylethylamino group, a methylphenylamino group, a
benzylhexylamino group, a bistrimethylsilylamino group or a
bi-tert-butyldimethylsilylamino group, and particularly useful is a
dimethylamino group or a diethylamino group; examples of the
(C1-C20) alkyl, (C6-C30) aryl, (C6-C30) aryl(C1-C20) alkyl or
(C1-C20) alkylsilyl substituted amide group include a dibenzylamide
group, a methylethylamide group, a methylphenylamide group or a
benzylhexylamide group, and particularly useful is a diphenylamide
group; examples of the (C1-C20) alkyl, (C6-C30) aryl, (C6-C30)
aryl(C1-C20) alkyl or (C1-C20) alkylsilyl substituted phosphine
group include a dimethylphosphine group, a diethylphosphine group,
a di-n-propylphosphine group, a diisopropylphosphine group, a
di-n-butylphosphine group, a di-sec-butylphosphine group, a
di-tert-butylphosphine group, a diisobutylphosphine group, a
tert-butylisopropylphosphine group, a di-n-hexylphosphine group, a
di-n-octylphosphine group, a di-n-decylphosphine group, a
diphenylphosphine group, a dibenzylphosphine group, a
methylethylphosphine group, a methylphenylphosphine group, a
benzylhexylphosphine group, a bistrimethylsilylphosphine group or a
bis-tert-butyldimethylsilylphosphine group; and examples of the
(C1-C20) alkyl, (C6-C30) aryl, (C6-C30) aryl(C1-C20) alkyl or
(C1-C20) alkylsilyl substituted phosphido group include a
dibenzylphosphido group, a methylethylphosphido group, a
methylphenylphosphido group, a benzylhexylphosphido group or a
bistrimethylsilylphosphido group.
[0020] Also, n is an integer of 1.about.4 selected by the oxidation
number of transition metal, and preferably an integer of 1 or
2.
[0021] The present invention provides an ethylene homopolymer or a
copolymer of ethylene and .alpha.-olefin, prepared using the
transition metal compound as a catalyst.
[0022] On the other hand, in order to use the transition metal
compound of Chemical Formula 1 as a catalyst component active for
olefin polymerization, while the ligand X of the transition metal
compound according to the present invention is extracted and the
central metal thereof is cationized, a boron compound, an aluminum
compound or a mixture thereof, corresponding to a counter ion
having weak bondability, namely, an anion, is utilized as a
co-catalyst. As such, the aluminum compound which is responsible
for removing a small amount of polar material such as water acting
as catalytic poison may function as an alkylating agent in the case
where the ligand X is halogen.
[0023] Useful as the co-catalyst in the present invention, the
boron compound may be selected from among compounds of Chemical
Formulas 2, 3 and 4 below as disclosed in U.S. Pat. No.
5,198,401.
B(R.sup.7).sub.3 [Chemical Formula 2]
[R.sup.8].sup.+[B(R.sup.7).sub.4].sup.- [Chemical Formula 3]
[(R.sup.9).sub.qZH].sup.+[B(R.sup.7).sub.4].sup.- [Chemical Formula
4]
[0024] [In Chemical Formulas 2 to 4, B is a boron atom; R.sup.7 is
a phenyl group, in which the phenyl group may be further
substituted with three to five substituents selected from among a
fluorine atom, a fluorine-substituted or unsubstituted (C1-C20)
alkyl group, and a fluorine-substituted or unsubstituted (C1-C20)
alkoxy group; R.sup.8 is a (C5-C7) cycloalkyl radical, a (C1-C20)
alkyl(C6-C20) aryl radical or a (C6-C30) aryl(C1-C20) alkyl
radical, for example, a triphenylmethyl radical; Z is a nitrogen
atom or a phosphorus atom; R.sup.9 is a (C1-C20) alkyl radical or
an anilinium radical substituted with two (C1-C4) alkyl groups
along with a nitrogen atom; and q is an integer of 2 or 3.]
[0025] Preferred examples of the boron-based co-catalyst include
one or more selected from among tris(pentafluorophenyl)borane,
tris(2,3,5,6-tetrafluorophenyl)borane,
tris(2,3,4,5-tetrafluorophenyl)borane,
tris(3,4,5-trifluorophenyl)borane,
tris(2,3,4-trifluorophenyl)borane,
phenylbis(pentafluorophenyl)borane,
tetrakis(pentafluorophenyl)borate,
tetrakis(2,3,5,6-tetrafluorophenyl)borate,
tetrakis(2,3,4,5-tetrafluorophenyl)borate,
tetrakis(3,4,5-trifluorophenyl)borate,
tetrakis(2,2,4-trifluorophenyl)borate,
phenylbis(pentafluorophenyl)borate and
tetrakis(3,5-bistrifluoromethylphenyl)borate, and specific
combination examples thereof include ferrocenium
tetrakis(pentafluorophenyl)borate, 1,1'-dimethylferrocenium
tetrakis(pentafluorophenyl)borate,
tetrakis(pentafluorophenyl)borate, triphenylmethyl
tetrakis(pentafluorophenyl)borate, triphenylmethyl
tetrakis(3,5-bistrifluoromethylphenyl)borate, triethylammonium
tetrakis(pentafluorophenyl)borate, tripropylammonium
tetrakis(pentafluorophenyl)borate, tri(n-butyl) ammonium
tetrakis(pentafluorophenyl)borate, tri(n-butyl) ammonium
tetrakis(3,5-bistrifluoromethylphenyl)borate, N,N-dimethylanilinium
tetrakis(pentafluorophenyl)borate, N,N-diethylanilinium
tetrakis(pentafluorophenyl)borate, N,N-2,4,6-pentamethylanilinium
tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium
tetrakis(3,5-bistrifluoromethylphenyl)borate, diisopropylammonium
tetrakis(pentafluorophenyl)borate, dicyclohexylammonium
tetrakis(pentafluorophenyl)borate, triphenylphosphonium
tetrakis(pentafluorophenyl)borate, tri(methylphenyl)phosphonium
tetrakis(pentafluorophenyl)borate or tri(dimethylphenyl)phosphonium
tetrakis(pentafluorophenyl)borate, and particularly useful is
N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate,
triphenylmethyl tetrakis(pentafluorophenyl)borate or
tris(pentafluoro)borane.
[0026] The aluminum compound used in the present invention may
include an aluminoxane compound of Chemical Formula 5 or 6 below,
an organic aluminum compound of Chemical Formula 7 below, or an
organic aluminum hydrocarbyl oxide compound of Chemical Formula 8
or 9 below.
(--Al(R.sup.10)--O--).sub.m [Chemical Formula 5]
(R.sup.10).sub.2Al--(--O(R.sup.10)--).sub.p--(R.sup.10).sub.2
[Chemical Formula 6]
(R.sup.11).sub.rAl(E).sub.3-r [Chemical Formula 7]
(R.sup.12).sub.2AlOR.sup.13 [Chemical Formula 8]
R.sup.12Al(OR.sup.13).sub.2 [Chemical Formula 9]
[0027] [In Chemical Formulas 5 to 9, R.sup.10 is a linear or
non-linear (C1-C20) alkyl group, and preferably is a methyl group
or an isobutyl group; m and p are independently an integer of
5.about.20; R.sup.11 and R.sup.12 are independently a (C1-C20)
alkyl group; E is a hydrogen atom or a halogen atom; r is an
integer of 1.about.3; and R.sup.13 is a (C1-C20) alkyl group or a
(C6-C30) aryl group.]
[0028] Useful as the co-catalyst, the aluminum compound is one or
more selected from aluminoxane and organic aluminum, and the
aluminoxane compound may include methylaluminoxane, modified
methylaluminoxane or tetraisobutylaluminoxane; and the organic
aluminum compound is selected from among trialkylaluminum,
dialkylaluminum chloride, alkylaluminum dichloride, and
dialkylaluminum hydride. Specific examples of the organic aluminum
compound include trialkylaluminum, including trimethylaluminum,
triethylaluminum, tripropylaluminum, triisobutylaluminum and
trihexylaluminum; dialkylaluminum chloride, including
dimethylaluminum chloride, diethylaluminum chloride,
dipropylaluminum chloride, diisobutylaluminum chloride, and
dihexylaluminum chloride; alkylaluminum dichloride, including
methylaluminum dichloride, ethylaluminum dichloride, propylaluminum
dichloride, isobutylaluminum dichloride and hexylaluminum
dichloride; and dialkylaluminum hydride, including dimethylaluminum
hydride, diethylaluminum hydride, dipropylaluminum hydride,
diisobutylaluminum hydride and dihexylaluminum hydride, and
preferably useful is trialkylaluminum, and more preferably is
triethylaluminum or triisobutylaluminum, in which the molar ratio
of central transition metal (M) to aluminum atom (Al) is
1:50.about.5,000.
[0029] As the ratio of transition metal compound to co-catalyst,
the molar ratio of central transition metal (M) to boron atom (B)
to aluminum atom (Al) is 1:0.1.about.100:10.about.1,000, and more
preferably 1:0.5.about.5:25.about.500. The preparation of an
ethylene homopolymer or a copolymer of ethylene and .alpha.-olefin
is possible within the above range, and the range of the ratio may
vary depending on the purity of reaction.
[0030] In another aspect, the present invention provides an
ethylene homopolymer or a copolymer of ethylene and .alpha.-olefin,
prepared using the transition metal compound as the catalyst
composition, and the preparation method is performed in a solution
phase by brining the transition metal compound, the co-catalyst,
and ethylene or .alpha.-olefin comonomer into contact with each
other in the presence of an appropriate solvent. As such, the
transition metal compound and the co-catalyst component may be
separately added into a reactor or respective components may be
pre-mixed and then introduced into a reactor.
[0031] The organic solvent used in the preparation method is
preferably a (C3-C20)hydrocarbon, and specific examples thereof
include butane, isobutane, pentane, hexane, heptane, octane,
isooctane, nonane, decane, dodecane, cyclohexane,
methylcyclohexane, benzene, toluene and xylene.
[0032] Specifically, upon preparation of the ethylene homopolymer,
an ethylene monomer is used alone, and the pressure of ethylene
suitable for the present invention is 1.about.1000 atm, and
preferably 10.about.150 atm. When the pressure falls in the above
range, a reactor made of a thin material may be used and there is
no need for an additional compression process, thus generating
economic benefits and increasing the yield of polymer. The
polymerization temperature is 60.about.300.degree. C., and
preferably 80.about.250.degree. C. If the polymerization
temperature is 80.degree. C. or higher, low-density polymers may be
prepared thanks to advanced comonomer incorporations. In contrast,
if the polymerization temperature is 250.degree. C. or lower, the
conversion from ethylene into polymer may increase, thus obtaining
high-density polymers.
[0033] Also in the method of preparing an ethylene homopolymer or a
copolymer of ethylene and .alpha.-olefin using the transition metal
catalyst composition, the comonomer which is polymerized with
ethylene may include .alpha.-olefin of (C3-C18)hydrocarbon, and is
preferably selected from among propylene, 1-butene, 1-pentene,
4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene,
1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene,
and 1-itocene. More preferably, 1-butene, 1-hexene, 1-octene, or
1-decene may be copolymerized with ethylene. In this case, the
preferred ethylene pressure and polymerization temperature are the
same as in the preparation of high-density polyethylene, and the
ethylene copolymer prepared using the method according to the
present invention has an ethylene content of 50 wt % or more,
preferably 60 wt % or more, and more preferably 60.about.99 wt %.
As mentioned above, when using .alpha.-olefin of (C4-C10)
hydrocarbon as the comonomer, the resultant linear low-density
polyethylene (LLDPE) has a density of 0.850.about.0.950 g/cc, and
preferably the preparation of an olefinic copolymer having a
density of 0.860.about.0.940 g/cc is possible.
[0034] In order to regulate the molecular weight upon preparation
of the ethylene homopolymer or copolymer according to the present
invention, hydrogen may be used as a molecular weight regulating
agent, so that a weight average molecular weight (Mw) is
80,000.about.500,000, and a molecular weight distribution (Mw/Mn)
which is the ratio of weight average molecular weight/number
average molecular weight is 1.5.about.4.1.
[0035] The catalyst composition according to the present invention
is present in a uniform form in the polymerization reactor, and
thus is preferably applied to solution polymerization that is
carried out at a temperature not lower than the melting point of
the corresponding polymer. However, as disclosed in U.S. Pat. No.
4,752,597, a heterogeneous catalytic system resulting from
supporting the above transition metal compound and a co-catalyst on
a porous metal oxide support may be employed in slurry
polymerization or gas polymerization.
[0036] According to the present invention, a transition metal
compound or a catalyst composition including the transition metal
compound can be easily produced at high yield using a simple
process by reducing the number of alkyls except for a specific
portion of cyclopentadiene, thus generating economic benefits.
Furthermore, the catalyst has high thermal stability and thus
maintains high catalytic activity upon olefin polymerization under
high-temperature solution polymerization conditions and also
enables the preparation of a high-molecular-weight polymer at high
yield. Also, because the catalyst is advanced in terms of comonomer
incorporations, its industrial availability is higher compared to
conventionally known metallocene and non-metallocene based
catalysts having single active sites.
[0037] Thus, the transition metal catalyst composition and the
preparation method according to the present invention can be
efficiently utilized for preparing copolymers of ethylene and
.alpha.-olefin, having various properties and elastic moduli.
DETAILED DESCRIPTION OF THE INVENTION
[0038] A better understanding of the present invention may be
obtained via the following examples that are set forth to
illustrate, but are not to be construed as limiting, the present
invention.
[0039] Unless otherwise stated, all ligands and catalyst synthesis
tests were performed using standard Schlenk or glove box techniques
in a nitrogen atmosphere, and the organic solvent used in the
reaction was refluxed in the presence of sodium metal and
benzophenone to remove water, and then distilled just before use.
The .sup.1H-NMR analysis of the synthesized ligand and catalyst was
performed at room temperature using a Bruker 500 MHz
spectrometer.
[0040] As a polymerization solvent, cyclohexane was sequentially
passed through Q-5 catalyst (available from BASF), silica gel, and
activated alumina of the reactor, and bubbled with high-purity
nitrogen, thus sufficiently removing water, oxygen and other
catalyst poisoning materials, and then used.
[0041] The resultant polymer was analyzed via the following
methods.
[0042] 1. Melt Flow Index (MI)
[0043] Measurement was performed according to ASTM D 2839.
[0044] 2. Density
[0045] According to ASTM D 1505, measurement was performed using a
density gradient tube.
[0046] 3. Analysis of Melting Point (Tm)
[0047] Measurement was performed under 2.sup.nd heating conditions
at a rate of 10.degree. C./min in a nitrogen atmosphere using
Dupont DSC2910.
[0048] 4. Molecular weight and molecular weight distribution
[0049] Measurement was performed in the presence of
1,2,3-trichlorobenzene solvent at a rate of 1.0 mL/min at
135.degree. C. using PL210 GPC equipped with PL Mixed-BX2+preCol,
and the molecular weight was corrected using a PL polystyrene
standard material.
[0050] 5. .alpha.-Olefin Content of Copolymer (wt %)
[0051] Measurement was performed in .sup.13C-NMR mode at
120.degree. C. in the presence of a solvent mixture comprising
1,2,4-trichlorobenzene/C6D.sub.6 (7/3 weight ratio) at 125 MHz
using a Bruker DRX500 nuclear magnetic resonance spectrometer.
[0052] (Reference: Randal, J. C. JMS-Rev. Macromol. Chem. Phys.
1980, C29, 201)
Preparative Example 1
Synthesis of
(dichloro)(tert-butylamido)(3,4-dimethylcyclopentadienyl)(dimethylsilane)-
titanium (IV)
(1) Synthesis of Crotonic Acid Isopropyl Ester
[0053] Crotonic acid (193.7 g, 2.25 mol) was dissolved in
2-propanol (860 mL, 11.25 mol) in a 2 L flask and then well
stirred, after which sulfuric acid (24 mL, 0.45 mol) was slowly
added in droplets to the mixture and refluxed and stirred for 48
hours or longer. The stirred mixture was cooled to room
temperature, after which the obtained mixture was washed with
distilled water (1000 mL), and the organic layer was separated,
neutralized and subjected to atmospheric distillation (80.degree.
C.), thus obtaining 220 g (1.71 mol, yield 76.3%) of crotonic acid
isopropyl ester.
[0054] .sup.1H-NMR(C6D.sub.6) .delta.=1.01.about.1.06 (d, 6H),
1.26.about.1.37 (q, 3H), 5.01.about.5.08 (m, 1H), 5.70.about.5.79
(m, 1H), 6.82.about.6.93 (m, 1H) ppm
(2) Synthesis of 3,4-dimethyl-2-cyclopentenone
[0055] 1 L of polyphosphoric acid was added into a 2 L flask,
purged with nitrogen, and then refluxed and stirred at 100.degree.
C., after which crotonic acid isopropyl ester (76.9 g, 0.6 mol) was
slowly added in droplets thereto, and the mixture was stirred for 3
hours and thus turned into dark brown. The mixture thus obtained
was mixed with ice water (500 mL) and then neutralized with sodium
carbonate, after which the organic layer was extracted with
ethylether and then subjected to vacuum distillation (105.degree.
C., 40 torr), thus obtaining 56 g (0.51 mol, yield 84.7%) of
3,4-dimethyl-2-cyclopentenone as a colorless transparent
liquid.
[0056] .sup.1H-NMR (CDCl.sub.3) .delta.=1.05.about.1.09 (d, 3H),
1.83.about.1.87 (q, 1H), 1.98 (s, 3H), 2.45.about.2.51 (q, 1H),
2.67.about.2.70 (m, 1H), 5.73 (s, 1H) ppm
(3) Synthesis of
tert-butyl-1-(3,4-dimethylcyclopentadienyl)-1,1-dimethylsilaneamine
[0057] In a nitrogen atmosphere, lithium aluminum hydride (6.07 g,
0.16 mol) was dissolved in diethylether (250 mL), and
3,4-dimethyl-2-cyclopentenone (33.95 g, 0.31 mol) was slowly added
in droplets thereto at 0.degree. C. Refluxing for 30 minutes and
cooling to 0.degree. C. via room temperature were performed, after
which distilled water (15 mL) was slowly added in droplets thereto
and thus unreacted lithium aluminum hydride was removed. The
reaction mixture was slowly added to dilute sulfuric acid and the
organic layer was extracted with diethylether and then subjected to
vacuum distillation, thus obtaining 21.2 g of
2,3-dimethylcyclopentadiene as a yellow liquid. This solution was
transferred into a flask and dissolved in pentane (200 mL), after
which n-butyl lithium (141 mL, 0.225 mol, 1.6 M) was added in
droplets thereto at -78.degree. C. The temperature was increased to
room temperature and the reaction was then carried out for 12
hours, thus obtaining 10.5 g (yield 46.9%) of
1,2-dimethylcyclopentadienyl lithium as off-white powder. 5.45 g
(54.5 mmol) of the powder was placed in a flask containing
diethylether (80 mL), and dichlorodimethylsilane (6.8 mL, 54.5
mmol) was then added in droplets thereto at -78.degree. C.
Subsequently, the temperature was increased to room temperature and
the reaction was carried out for 12 hours or longer. Diethylether
was removed using vacuum distillation, and the resultant product
was washed with pentane, thus obtaining 6.35 g (yield 62.4%) of
dimethylsilyl-3,4-dimethylcyclopentadienyl chloride as a yellow
liquid. This liquid was transferred into a flask without
purification and then dissolved in tetrahydrofuran (90 mL), after
which lithium-tert-butylamine (2.69 g, 34.0 mmol) was slowly added
in droplets thereto at -78.degree. C. The reaction was carried out
at room temperature for 12 hours or longer and the solvent was then
completely removed using vacuum drying, after which the resultant
product was extracted with purified pentane, thus obtaining, as a
yellow liquid, 6.15 g (27.5 mmol, yield 80.9%) of
tert-butyl-1-(3,4-dimethylcyclopentadienyl)-1,1-dimethylsilaneamine.
[0058] .sup.1H NMR(C6D.sub.6): .delta.=0.00 (s, 6H), 0.28 (s, 3H),
1.05 (s, 3H), 1.07 (s, 9H), 1.09 (s, 3H), 1.85 (s, 2H), 1.94 (s,
2H), 1.98 (s, 6H), 2.89 (t, 1H), 3.17 (t, 1H), 6.16 (s, 2H),
6.31.about.6.70 (m, 1H) ppm
(4) Synthesis of
(dichloro)(tert-butylamido)(3,4-dimethylcyclopentadienyl)(dimethylsilane)-
titanium (IV)
[0059]
tert-Butyl-1-(3,4-dimethylcyclopentadienyl)-1,1-dimethylsilaneamine
(6.15 g, 27.5 mmol) was placed in a flask and dissolved in
diethylether (100 mL) in a nitrogen atmosphere, after which n-butyl
lithium (22.0 mL) was slowly added in droplets thereto at
-78.degree. C. The temperature was gradually increased to room
temperature and the reaction was carried out for 12 hours or
longer. The solvent was completely removed using vacuum drying and
the resultant product was washed with pentane, thus obtaining as
off-white powder 5.24 g (yield 81.0%) of lithium
(tert-butylamido)(3,4-dimethylcyclopentadienyl)dimethylsilane. 3.00
g (12.8 mmol) of the powder and
tetrachlorobis(tetrahydrofuran)titanium (IV) (4.26 g, 12.8 mmol)
were placed together in a flask and toluene (50 mL) was added
thereto so that the reaction was carried out at 80.degree. C. for
24 hours or longer. The temperature was decreased to room
temperature and filtration was conducted thus removing lithium
chloride, and solvent was removed using vacuum drying, after which
the resultant product was extracted with pentane and
recrystallized, thus obtaining as a yellow solid 1.73 g (yield
39.9%) of (dichloro)(tert-butylamido)(3,4-dimethylcyclopentadienyl)
(dimethylsilane) titanium (IV).
[0060] .sup.1H NMR(C6D.sub.6): .delta.=0.26 (s, 6H), 1.40 (s, 9H),
2.04 (s, 6H), 5.91 (s, 2H) ppm; .sup.13C NMR (C6D.sub.6):
.delta.=0.97, 13.41, 33.18, 105.91, 123.05, 127.84, 128.22, 133.45
ppm.
Preparative Example 2
Synthesis of
(dichloro)(tert-butylamido)(3,4-dimethylcyclopentadienyl)(dimethylsilane)-
zirconium (IV)
[0061]
Lithium(tert-butylamido)3,4-dimethylcyclopentadienyldimethylsilane
(0.9 g, 3.83 mmol) and zirconium (IV) chloride (0.891 g, 3.83 mmol)
were placed together in a flask and toluene (20 mL) was added
thereto so that the reaction was carried out at 80.degree. C. for
24 hours or longer. The temperature was decreased to room
temperature and filtration was conducted thus removing lithium
chloride and solvent was removed using vacuum drying, after which
the resultant product was extracted with pentane and
recrystallized, thus obtaining as a pale brown solid 0.89 g (yield
60.5%) of (dichloro)
(tert-butylamido)(3,4-dimethylcyclopentadienyl)(dimethylsilane)zirconium
(IV).
[0062] .sup.1H NMR(C6D.sub.6): .delta.=0.30 (s, 6H), 1.31 (s, 9H),
2.00 (s, 6H), 5.90 (s, 2H) ppm; .sup.13C NMR (C6D.sub.6):
.delta.=0.07, 14.36, 32.65, 107.74, 126.86, 126.91, 128.82, 139.34
ppm.
Comparative Preparative Example 1
Synthesis of
(dichloro)(tert-butylamido)(2,3,4,5-tetramethylcyclopentadienyl)(dimethyl-
silane)titanium (IV)
(1) Synthesis of
(tert-butylamino)(2,3,4,5-tetramethylcyclopenta-2,4-dienyl)dimethylsilane
[0063] 2,3,4,5-tetramethylcyclopenta-2,4-diene (3.67 g, 30 mmol)
was added into a flask containing tetrahydrofuran (100 mL), n-butyl
lithium (12 mL) was added in droplets thereto at 0.degree. C., and
the reaction temperature was gradually increased to room
temperature so that the reaction was carried out for 8 hours. This
solution was cooled to -78.degree. C., dichloromethylsilane (3.87
g, 30 mmol) was slowly added in droplets thereto, and then the
reaction was carried out for 12 hours. After the reaction, the
volatile material was removed, and the resultant product was
extracted with hexane (100 mL), after which the volatile material
was removed, thereby obtaining as pale yellow oil 5.5 g of (chloro)
(dimethyl) (2,3,4,5-tetramethylcyclopentadienyl)silane. The
(chloro)(dimethyl)(2,3,4,5-tetramethylcyclopentadienyl)silane thus
obtained was dissolved in tetrahydrofuran (100 mL) without
additional purification, after which lithium tert-butylamide (2.02
g) was added in droplets thereto at 0.degree. C. and the reaction
was carried out at room temperature for 2 hours. After the
reaction, the volatile material was removed, and the resultant
product was extracted with hexane (100 mL), thus obtaining as pale
yellow oil 6.09 g (yield 81%) of
(tert-butylamino)(2,3,4,5-tetramethylcyclopenta-2,4-dienyl)dimethylsilane-
.
[0064] .sup.1H-NMR(C6D.sub.6) .delta.=0.11 (s, 6H), 1.11 (s, 9H),
1.86 (s, 6H), 2.00 (s, 6H) 2.78 (s, 1H) ppm
(2) Synthesis of
(dichloro)(tert-butylamido)(2,3,4,5-tetramethylcyclopentadienyl)(dimethyl-
silane)titanium (IV)
[0065]
(tert-Butylamino)(2,3,4,5-tetramethylcyclopenta-2,4-dienyl)dimethyl-
silane (6.09 g 24.2 mmol) was dissolved in diethylether (100 mL),
and n-butyl lithium (9.7 mL) was added in droplets thereto at
-78.degree. C., after which the reaction temperature was gradually
increased to room temperature and the reaction was carried out for
12 hours. After the reaction, the volatile material was removed,
and the resultant product was extracted with hexane (100 mL) thus
obtaining 6.25 g of an orange-colored solid. The solid thus
obtained was dissolved in toluene (100 mL), and tetrachlorotitanium
(IV) (4.50 g 23.7 mmol) was added in droplets thereto at
-78.degree. C., after which the reaction temperature was increased
to room temperature and the reaction was carried out for 7 hours.
After completion of the reaction, the volatile material was
removed, and the resultant product was extracted with purified
pentane (100 mL) and recrystallized at -35.degree. C., filtered and
then vacuum dried, thus obtaining as an orange-colored solid 0.87
g(yield 10%) of
(dichloro)(tert-butylamido)(2,3,4,5-tetramethylcyclopentadienyl)(dimethyl-
silane)titanium (IV).
[0066] .sup.1H-NMR(C6D.sub.6) .delta.=0.43 (s, 6H), 1.43 (s, 9H),
2.00 (s, 6H), 2.01 (s, 6H) ppm
Comparative Preparative Example 2
Synthesis of
(dichloro)(tert-butylamido)(2,3,4,5-tetramethylcyclopentadienyl)(dimethyl-
silane)zirconium (IV)
[0067] 1.3 g (yield 13.3%) of (dichloro)
(tert-butylamido)(2,3,4,5-tetramethylcyclopentadienyl)(dimethylsilane)zir-
conium (IV) was synthesized in the same manner as in Comparative
Preparative Example 1, with the exception that 5.52 g (23.7 mmol)
of tetrachlorozirconium (IV) was used.
[0068] .sup.1H-NMR(C6D.sub.6) .delta.=0.40 (s, 6H), 1.40 (s, 9H),
1.97 (s, 6H), 2.00 (s, 6H) ppm.
Example 1
[0069] Ethylene and 1-octene was copolymerized via the following
procedures using a batch type polymerization device. Specifically,
1170 mL of cyclohexane and 30 mL of 1-octene were added into a 2000
mL stainless steel reactor sufficiently dried and purged with
nitrogen, after which 22.1 mL of modified methylaluminoxane-7
(available from Akzo Nobel, modified MAO-7, 7 wt % Al Isopar
solution) 54.2 mM toluene solution was fed into the reactor. The
temperature of the reactor was increased to 80.degree. C., after
which 0.4 mL of the
(dichloro)(tert-butylamido)(3,4-dimethylcyclopentadienyl)(dimethylsilane)-
titanium (IV) (5.0 mM toluene solution) synthesized in Preparative
Example 1 and 2.0 mL of triphenylmethylinium tetrakis
pentafluorophenylborate (99%, Boulder Scientific) 10 mM toluene
solution were sequentially added thereto, and the inner pressure of
the reactor was adjusted up to 30 kg/cm.sup.2 with ethylene, after
which polymerization was carried out.
[0070] During the reaction time of 5 minutes, the temperature
arrived at 162.2.degree. C. in maximum. After 5 minutes, 100 mL of
ethanol containing 10 vol % hydrochloric acid aqueous solution was
added thereto, thus terminating the polymerization, after which
stirring was performed using 1.5 L of ethanol for 1 hour, followed
by filtering and separating the reaction product. The recovered
reaction product was dried in a vacuum oven at 60.degree. C. for 8
hours, yielding 62.8 g of a polymer. The polymer had a melting
point of 117.48.degree. C., a melt index of 0.016, and a density of
0.9124 g/cc, and upon analysis using gel chromatography, a weight
average molecular weight (Mw) of 202,000 g/mol, a molecular weight
distribution (Mw/Mn) of 4.05, and a 1-octene content of 7.68 wt
%.
Example 2
[0071] Ethylene and 1-octene were copolymerized in the same manner
as in Example 1, with the exception that the reaction temperature
was increased up to 140.degree. C. before adding the catalyst.
During the reaction time of 5 minutes, the temperature arrived at
180.9.degree. C. in maximum, and 48.04 g of a polymer was finally
obtained. The polymer had a melting point of 119.02.degree. C., a
melt index of 1.5, a density of 0.9152 g/cc, and upon analysis
using gel chromatography, a Mw of 109,100 g/mol, a Mw/Mn of 2.33,
and a 1-octene content of 4.98 wt %.
Example 3
[0072] Ethylene and 1-octene were copolymerized in the same manner
as in Example 1, with the exception that 0.4 mL of the
(dichloro)(tert-butylamido)
(3,4-dimethylcyclopentadienyl)(dimethylsilane)zirconium (IV) (5.0
mM toluene solution) synthesized in Preparative Example 2 was added
and the reaction time was set to 10 minutes. During the reaction
time of 10 minutes, the temperature arrived at 98.2.degree. C. in
maximum, and 4.62 g of a polymer was finally obtained. The polymer
had a melting point of 133.28.degree. C., a melt index of 0.165, a
density of 0.9370 g/cc, and upon analysis using gel chromatography,
a Mw of 211,600 g/mol, a Mw/Mn of 3.13, and a 1-octene content of
0.82 wt %.
Comparative Example 1
[0073] Ethylene and 1-octene were copolymerized in the same manner
as in Example 1, with the exception that the (dichloro)
(tert-butylamido)
(2,3,4,5-tetramethylcyclopentadienyl)(dimethylsilane)titanium (IV)
synthesized in Comparative Preparative Example 1 was added. During
the reaction time of 5 minutes, the temperature arrived at
163.0.degree. C. in maximum, and 66.68 g of a polymer was finally
obtained. The polymer had a melting point of 116.35.degree. C., a
melt index of 0.004, a density of 0.9420 g/cc, and upon analysis
using gel chromatography, a Mw of 247,800 g/mol, a Mw/Mn of 7.30,
and a 1-octene content of 6.55 wt %.
Comparative Example 2
[0074] Ethylene and 1-octene were copolymerized in the same manner
as in Example 1, with the exception that the reaction temperature
was increased up to 140.degree. C. before adding the catalyst, and
the
(dichloro)(tert-butylamido)(2,3,4,5-tetramethylcyclopentadienyl)(dimethyl-
silane)titanium (IV) synthesized in Comparative Preparative Example
1 was added. During the reaction time of 5 minutes, the temperature
arrived at 184.4.degree. C. in maximum, and 40.03 g of a polymer
was finally obtained. The polymer had a melting point of
116.21.degree. C., a melt index of 0.56, a density of 0.9218 g/cc,
and upon analysis using gel chromatography, a Mw of 106,000 g/mol,
a Mw/Mn of 4.31, and a 1-octene content of 6.34 wt %.
Comparative Example 3
[0075] Ethylene and 1-octene were copolymerized in the same manner
as in Example 1, with the exception that 0.4 mL of the
(dichloro)(tert-butylamido)(2,3,4,5-tetramethylcyclopentadienyl)(dimethyl-
silane)zirconium (IV) (5.0 mM toluene solution) synthesized in
Comparative Preparative Example 2 was added and the reaction time
was set to 10 minutes. During the reaction time of 10 minutes, the
temperature arrived at 102.1.degree. C. in maximum, and 16.49 g of
a polymer was finally obtained. The polymer had a melting point of
125.93.degree. C., a melt index of 0.087, a density of 0.9405 g/cc,
and upon analysis using gel chromatography, a Mw of 426,800 g/mol,
a Mw/Mn of 3.31, and a 1-octene content of 2.2 wt %.
[0076] As is apparent from the above examples, in the
polymerization of ethylene alone and in combination with 1-octene
under the above polymerization conditions, the polymers could be
produced at higher yield, and olefin copolymers having higher
1-octene contents were obtained under the same conditions, compared
to the comparative examples. In particular, low-density copolymers
could be successfully prepared from ethylene and 1-octene.
[0077] Although the preferred embodiments of the present invention
have been disclosed for illustrative purposes, those skilled in the
art will appreciate that various modifications, additions, and
substitutions are possible, without departing from the scope and
spirit of the invention as disclosed in the accompanying
claims.
* * * * *