U.S. patent application number 09/300289 was filed with the patent office on 2002-02-14 for novel metallocene compound, and process for preparing polyolefin by using it.
Invention is credited to ISHII, YUKIO, MICHIUE, KENJI, SUNAGA, TADAHIRO, YAMASHITA, MASAHIRO.
Application Number | 20020019504 09/300289 |
Document ID | / |
Family ID | 14864011 |
Filed Date | 2002-02-14 |
United States Patent
Application |
20020019504 |
Kind Code |
A1 |
SUNAGA, TADAHIRO ; et
al. |
February 14, 2002 |
NOVEL METALLOCENE COMPOUND, AND PROCESS FOR PREPARING POLYOLEFIN BY
USING IT
Abstract
There are herein disclosed a novel metallocene compound
represented by the formula [1] and a process for preparing a
polyolefin comprising the step of polymerizing an olefin in a
catalytic system including the metallocene compound. The
metallocene compound of the present invention particularly permits
the preparation of a polyolefin having a high stereoregularity and
a low molecular weight, and it is industrially extremely valuable:
1 wherein R.sup.1 and R.sup.2 are each selected from the group
consisting of an alkyl group, an aryl group and a
silicon-containing alkyl group; M is a metal selected from the
group IV of the periodic table; Q is carbon or silicon; X is a
halogen, an alkyl group or an anionic ligand, and they may be
selected so as to be the same or a combination of different ones; i
is an integer of 1 to 10; n is an integer of 1 to 4; m is an
integer of 0 to 4; and h is an integer of 1 to 3.
Inventors: |
SUNAGA, TADAHIRO; (KANAGAWA,
JP) ; MICHIUE, KENJI; (HIROSHIMA, JP) ;
YAMASHITA, MASAHIRO; (HIROSHIMA, JP) ; ISHII,
YUKIO; (OSAKA, JP) |
Correspondence
Address: |
BURNS DOANE SWECKER & MATHIS L L P
POST OFFICE BOX 1404
ALEXANDRIA
VA
22313-1404
US
|
Family ID: |
14864011 |
Appl. No.: |
09/300289 |
Filed: |
April 27, 1999 |
Current U.S.
Class: |
526/160 |
Current CPC
Class: |
C08F 4/65908 20130101;
C08F 10/00 20130101; Y10S 526/943 20130101; C08F 110/06 20130101;
C07F 17/00 20130101; C08F 4/65912 20130101; C08F 10/00 20130101;
C08F 4/65927 20130101; C08F 110/06 20130101; C08F 2500/16
20130101 |
Class at
Publication: |
526/160 |
International
Class: |
C07F 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 6, 1998 |
JP |
123576/1998 |
Claims
What is claimed is:
1. A novel metallocene compound represented by the formula [1]
6wherein R.sup.1 and R.sup.2 are each selected from the group
consisting of an alkyl group, an aryl group and a
silicon-containing alkyl group; M is a metal selected from the
group IV of the periodic table; Q is carbon or silicon; X is a
halogen, an alkyl group or an anionic ligand, and they may be
selected so as to be the same or a combination of different ones; i
is an integer of 1 to 10; n is an integer of 1 to 4; m is an
integer of 0 to 4; and h is an integer of 1 to 3.
2. The metallocene compound according to claim 1 wherein, in the
formula [1], R.sup.1 and R.sup.2 are tert-butyl groups at the 2
position and the 7 position of the formula [1], respectively; each
of n and m is 1; i is 4; M is zirconium; Q is carbon; X is
chlorine; and h is 2.
3. A process for preparing a polyolefin which comprises the step of
polymerizing an olefin by the use of a system including a
metallocene compound represented by the formula [1].
4. The process for preparing the polyolefin according to claim 3
wherein the metallocene compound represented by the formula [1] and
an organic aluminoxane are used.
5. The process for preparing the polyolefin according to claim 3
wherein there is used a system including the metallocene compound
represented by the formula [1], and an ionic compound which can
convert the metallocene compound into a cationic compound to
produce a stable anionic species.
6. The process for preparing the polyolefin according to claim 3
wherein an organic aluminum compound is further used together.
7. The process for preparing the polyolefin according to claim 3
wherein there are together used the metallocene compound
represented by the formula [1], and an organic aluminoxane
supported on a carrier which is insoluble in an inert organic
solvent.
8. The process for preparing the polyolefin according to claim 7
wherein the carrier is a polymer having a functional group.
9. The process for preparing the polyolefin according to claim 8
wherein the polymer is a polypropylene to which a dicarboxylic
anhydride is grafted.
10. The process for preparing the polyolefin according to claim 7
wherein the carrier is an inorganic oxide.
11. The process for preparing the polyolefin according to claim 3
wherein the polyolefin is a low-molecular weight polyolefin.
12. The process for preparing the polyolefin according to claim 3
wherein the polyolefin is a syndiotactic polypropylene.
Description
BACKGROUND OF THE INVENTION
[0001] (1) Field of the Invention
[0002] The present invention relates to a novel metallocene
compound, and a process for preparing a polyolefin polymerizing an
olefin by the use of this metallocene compound. More specifically,
it relates to a metallocene compound having a specific structure
and a process for preparing a polyolefin comprising the step of
polymerizing an olefin by the use of the metallocene compound.
[0003] (2) Description of the Prior Art
[0004] As homogeneous catalysts for olefin polymerization,
catalytic systems containing the so-called metallocene compound are
well known.
[0005] Processes for polymerizing olefins by the use of a catalytic
system containing a usual metallocene compound have been improved
from various angles.
[0006] In particular, a method for the stereoregular polymerization
of an .alpha.-olefin has been variously improved since a report was
made by W. Kaminsky et al. [Angew. Chem., Vol. 97, p. 507
(1985)].
[0007] As an improved example of such a method, there has been
reported a metallocene compound having a C2 symmetrical structure
in which some of hydrogen atoms on a cyclopentadienyl group
constituting a ligand moiety of the metallocene compound are
replaced with alkyl groups, and it has been prevalently attempted
to improve the stereoregularity of an isotactic polymer obtained
from the above-mentioned metallocene compound [Yamazaki et al.,
Chemistry Letters, p. 1853 (1989), and Japanese Patent Application
Laid-Open No. 268307/1992].
[0008] Furthermore, as similar attempts, many researches have been
reported in which the stereoregularity of an olefin polymer is to
be improved by a catalytic system including a metallocene compound
which has an ethylenebisindenyl derivative having the C2
symmetrical structure as a ligand [e.g., Organometallics, Vol. 13,
p. 954 (1994), J. Organmet. Chem., Vol. 288, p. 63 (1985) and the
like].
[0009] On the other hand, J. A. Ewen has found that an
.alpha.-olefin can be polymerized in a syndiotactic
stereoregularity by a catalytic system containing a metallocene
compound having a Cs symmetrical structure in which a
cyclopentadienyl group and a fluorenyl group are linked with
dimethyl methane bridge [J. Am. Chem. Soc., Vol. 110, p. 6255
(1988)]. In order to improve this metallocene compound, it has been
attempted to further control the stereoregularity by introducing a
2,7-di-tert-butylfluorenyl group in place of the fluorenyl group
(Japanese Patent Application Laid-Open No. 69394/1992).
[0010] However, it is difficult to synthesize a syndiotactic
.alpha.-olefin polymer having a high stereoregularity and a low
molecular weight by the use of the metallocene compound having the
Cs symmetrical structure under practical conditions of, for
example, using a large amount of hydrogen, and accordingly it has
been desired to further improve the metallocene compound.
SUMMARY OF THE INVENTION
[0011] For the purpose of solving the above-mentioned problems, the
present inventors have intensively investigated on a metallocene
compound having a novel structure capable of synthesizing an
.alpha.-olefin polymer and a polymerization process in which this
metallocene compound is used, and in consequence, the present
invention has been completed.
[0012] That is to say, the first aspect of the present invention is
directed to a novel metallocene compound represented by the formula
[1] 2
[0013] wherein R.sup.1 and R.sup.2 are each selected from the group
consisting of an alkyl group, an aryl group and a
silicon-containing alkyl group; M is a metal selected from the
group IV of the periodic table; Q is carbon or silicon; X is a
halogen, an alkyl group or an anionic ligand, and they may be
selected so as to be the same or a combination of different ones; i
is an integer of 1 to 10; n is an integer of 1 to 4; m is an
integer of 0 to 4; and h is an integer of 1 to 3.
[0014] The second aspect of the present invention is directed to a
process for preparing a polyolefin which comprises the step of
polymerizing an olefin by the use of a catalytic system containing
a metallocene compound containing represented by the formula
[1].
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] In the present invention, R.sup.1 and R.sup.2 of the formula
[1] are each selected from the group consisting of an alkyl group,
an aryl group and a silicon-containing alkyl group.
[0016] The above-mentioned alkyl group is preferably an alkyl group
having 1 to 20 carbon atoms, and typical examples of the alkyl
group include methyl, ethyl, n-propyl, isopropyl, 2-methylpropyl,
tert-butyl, cyclohexyl, norbornyl and menthyl.
[0017] The above-mentioned aryl group is preferably an aryl group
having 6 to 20 carbon atoms, and typical examples of the aryl group
include phenyl, tolyl and naphthyl.
[0018] The above-mentioned silicon-containing alkyl group is
preferably a silicon-containing alkyl group having 1 to 20 carbon
atoms, and typical examples of the silicon-containing alkyl group
include trimethylsilyl and dimethyl-ethylsilyl.
[0019] Furthermore, the substitutional position of each of R.sup.1
and R.sup.2 may be any position of the 1-position to 4-position, or
the 5-position to 8-position of fluorene; n is in the range of 1 to
4; and m is in the range of 0 to 4.
[0020] In the present invention, Q is carbon or silicon, and a
cycloalkyl group is formed in which i is in the range of 1 to
10.
[0021] Examples of the cycloalkyl group which can be constituted
herein include cyclopropylidene, cyclobutylidene, cyclopentylidene,
cyclohexylidene, cycloheptylidene, cyclodimethylenesilylene,
cyclotrimethylenesilylene, cyclotetramethylenesilylene,
cyclopentamethylenesilylene and cycloheptamethylenesilylene.
[0022] In the present invention, M of the formula [1] is a metal
selected from the group 4 of the periodic table, and examples of M
include titanium, zirconium and hafnium.
[0023] X of the formula [1] is a halogen, an alkyl group or an
anionic ligand, and they may be selected so as to be the same or a
combination of different ones.
[0024] Typical examples of the halogen include fluorine, chlorine,
bromine and iodine.
[0025] The alkyl group is preferably an alkyl group having 1 to 20
carbon atoms, and its typical examples include methyl, ethyl,
butyl, isopropyl and tert-butyl.
[0026] Typical examples of the anionic ligand include organic
phosphorus compounds such as trimethylphosphine, triethylphosphine,
triphenylphosphine and diphenylmethylphosphine; alkoxy groups such
as methoxy, tert-butoxy and phenoxy; and ethers such as
tetrahydrofuran (hereinafter referred to as "THF"), diethyl ether,
dioxane and 1,2-dimethoxyethane.
[0027] Among them, Xs may be the same or a combination of different
ones.
[0028] In the present invention, examples of the ligand which is a
precursor of the metallocene compound represented by the formula
[1] include
1-cyclopentadienyl-1-(2,7-di-tert-butylfluorenyl)cyclopropane,
1-cyclopentadienyl-1-(2,7-di-tert-butylfluorenyl)cyclobutane,
1-cyclopentadienyl-1-(2,7-di-tert-butylfluorenyl)cyclopentane,
1-cyclopentadienyl -1-(2,7-di-tert-butylfluorenyl)cyclohexane,
1-cyclopentadienyl-1-(2,7-di-tert-butylfluorenyl)cycloheptane,
1-cyclopentadienyl-l-(3,6-di-tert-butylfluorenyl)cyclopropane,
1-cyclopentadienyl-1-(3,6-di-tert-butylfluorenyl)cyclobutane,
1-cyclopentadienyl-1-(3,6-di-tert-butylfluorenyl) cyclopentane,
1-cyclopentadienyl-1-(3,6-di-tert-butylfluorenyl)-cyclohexane,
1-cyclopentadienyl-1-(3,6-di-tert-butyl-fluorenyl) cycloheptane,
1-cyclopentadienyl-1-(2,7-di(trimethylsilyl)fluorenyl)cyclopropane,
1-cyclopentadienyl-1-(2,7-di(trimethylsilyl)fluorenyl)cyclobutane,
1-cyclopentadienyl
-1-(2,7-di(trimethylsilyl)fluorenyl)cyclopentane,
1-cyclopentadienyl-1-(2,7-di(trimethylsilyl)fluorenyl)cyclohexane,
1-cyclopentadienyl-1-(2,7-di(triethylsilyl)fluorenyl)cycloheptane,
1-cyclopentadienyl-1-(2,7-diphenylfluorenyl)cyclopropane,
1-cyclopentadienyl-1-(2,7-diphenylfluorenyl)cyclobutane,
1-cyclopentadienyl-1-(2,7-diphenylfluorenyl)cyclopentane,
1-cyclopentadienyl-1-(2,7-diphenylfluorenyl)cyclohexane,
1-cyclopentadienyl-1-(2,7-diphenylfluorenyl)cycloheptane,
cyclopentadienyl-(2,7-di-tert-butylfluorenyl)cyclodimethylene
silane,
cyclopentadienyl-(2,7-di-tert-butylfluorenyl)cyclotrimethylene
silane, cyclopentadienyl-(2,7-di-tert-butylfluorenyl)
cyclotetramethylene silane,
cyclopentadienyl-(2,7-di-tert-butyl-fluorenyl)cyclopentamethylene
silane,
cyclopentadienyl-(2,7-di-tert-butylfluorenyl)cyclopentamethylene
silane, cyclopentadienyl
-(3,6-di-tert-butylfluorenyl)cyclodimethylene silane,
cyclopentadienyl-(3,6-di-tert-butylfluorenyl) cyclotrimethylene
silane,
cyclopentadienyl-(3,6-di-tert-butylfluorenyl)-cyclotetramethylene
silane,
cyclopentadienyl-(3,6-di-tert-butylfluorenyl)cyclopentamethylene
silane, cyclopentadienyl
-(3,6-di-tert-butylfluorenyl)cycloheptamethylene silane,
cyclopentadienyl-(2,7-di(trimethylsilyl)fluorenyl)cyclodimethylene
silane,
cyclopentadienyl-(2,7-di(trimethylsilyl)fluorenyl)cyclotrimethyle-
ne silane, cyclopentadienyl
-(2,7-di(trimethylsilyl)fluorenyl)cyclotetrame- thylene silane,
cyclopentadienyl-(2,7-di(trimethylsilyl)fluorenyl)cyclopen-
tamethylene silane,
cyclopentadienyl-(2,7-di(trimethylsilyl)fluorenyl)cycl-
oheptamethylene silane, cyclopentadienyl
-(2,7-diphenylfluorenyl)cyclodime- thylene silane, cyclopentadienyl
-(2,7-diphenylfluorenyl)cyclotrimethylene silane,
cyclopentadienyl-(2,7-diphenylfluorenyl)cyclotetramethylene silane,
cyclopentadienyl -(2,7-diphenylfluorenyl)cyclopentamethylene silane
and cyclopentadienyl-(2,7-diphenylfluorenyl)cycloheptamethylene
silane.
[0029] In the present invention, no particular restriction is put
on a preparation method of the ligand which is the precursor of the
metallocene compound represented by the formula [1], but for
example, it can be synthesized in accordance with the following
formula [2] or [3]. 3
[0030] wherein R.sup.1 and R.sup.2 are each selected from the group
consisting of an alkyl group, an aryl group and a
silicon-containing alkyl group; Q is carbon or silicon; L is an
alkali metal; i is an integer of 1 to 10; n is an integer of 1 to
4; and m is an integer of 0 to 4. 4
[0031] wherein R.sup.1 and R.sup.2 are each selected from the group
consisting of an alkyl group, an aryl group and a
silicon-containing alkyl group; Q is carbon or silicon; L is an
alkali metal; Z is a halogen; i is an integer of 1 to 10; n is an
integer of 1 to 4; and m is an integer of 0 to 4.
[0032] Examples of the alkali metal which can be particularly
preferably used in the above-mentioned reaction include lithium,
sodium and potassium, and examples of the halogen include fluorine,
chlorine, bromine and iodine.
[0033] The above-mentioned reaction can be carried out in the
temperature range of -80.degree. C. to 200.degree. C. in an organic
solvent, for example, an aliphatic hydrocarbon such as pentane,
hexane, heptane, cyclohexane or decalin, an aromatic hydrocarbon
such as benzene, toluene or xylene, or an ether such as THF,
diethyl ether, dioxane or 1,2-dimethoxy ethane.
[0034] Furthermore, the ligand which is the precursor of the
metallocene compound of the formula [1] obtained by the reaction of
the formula [2] or [3] is brought into contact with an alkali metal
hydride or an organic alkali metal in an organic solvent such as
the above-mentioned aliphatic hydrocarbon, aromatic hydrocarbon or
ether in the temperature range of -80.degree. C. to 200.degree. C.,
thereby forming a di-alkali metal salt.
[0035] Examples of the alkali metal which can be used in the
above-mentioned reaction include lithium, sodium and potassium, and
examples of the alkali metal hydride include sodium hydride and
potassium hydride.
[0036] The metallocene compound of the formula [1] can be
synthesized by reacting the di-alkali metal salt of the ligand with
a halide of a metal selected from the group 4 of the periodic
table.
[0037] Typical examples of the halide of the metal selected from
the group 4 of the periodic table include fluorides, chlorides,
bromides and iodides of trivalent and tetravalent titaniums,
complexes of these compounds and ethers such as THF, diethyl ether,
dioxane and 1,2-dimethoxyethane, tetrafluoride, tetrachloride,
tetrabromide and tetraiodide of zirconium and ether complexes
thereof, and tetrafluoride, tetrachloride, tetrabromide and
tetraiodide of hafnium and ether complexes thereof.
[0038] The reaction of the di-alkali metal salt with the halide of
the metal in the group 4 of the periodic table can be carried out
preferably in an organic solvent in the reaction temperature range
of -80.degree. C. to 200.degree. C. by using these material
preferably in equimolar amounts.
[0039] Examples of the preferably usable organic solvent include
aliphatic hydrocarbons such as pentane, hexane, heptane,
cyclohexane and decalin, aromatic hydrocarbons such as benzene,
toluene and xylene, ethers such as THF, diethyl ether, dioxane and
dimethoxy ethane, and halogenated hydrocarbons such as
dichloromethane and chloroform.
[0040] Typical examples of the metallocene compound represented by
the formula [1] for use in the present invention include, but are
not limited to, cyclopropylidene(cyclopentadienyl)
(2,7-di-tert-butyl-fluorenyl)zirco- nium dichloride,
cyclobutylidene(cyclopentadienyl) (2,7-di-tert-butyl-fluo-
renyl)zirconium dichloride, cyclopentylidene(cyclopentadienyl)
(2,7-di-tert-butyl-fluorenyl)zirconium dichloride,
cyclohexylidene(cyclopentadienyl)(2,7-di-tert-butyl-fluorenyl)zirconium
dichloride, cycloheptylidene(cyclopentadienyl)
(2,7-di-tert-butyl-fluoren- yl)zirconium dichloride,
cyclopropylidene(cyclopentadienyl)(3,6-di-tert-bu-
tyl-fluorenyl)zirconium dichloride,
cyclobutylidene(cyclopentadienyl)
(3,6-di-tert-butylfluorenyl)zirconium dichloride,
cyclopentylidene(cyclop-
entadienyl)(3,6-di-tert-butyl-fluorenyl)zirconium dichloride,
cyclohexylidene(cyclopentadienyl)
(3,6-di-tert-butyl-fluorenyl)zirconium dichloride,
cycloheptylidene(cyclopentadienyl)(3,6-di-tert-butyl-fluoreny-
l)zirconium dichloride, cyclopropylidene(cyclopentadienyl)
(2,7-di(trimethylsilyl)fluorenyl)zirconium dichloride,
cyclobutylidene(cyclopentadienyl)(2,7-di(trimethylsilyl)-fluorenyl)zircon-
ium dichloride, cyclopentylidene(cyclopentadienyl)
(2,7-di(trimethylsilyl)- fluorenyl)zirconium dichloride,
cyclohexylidene(cyclopentadienyl)(2,7-di(t-
rimethylsilyl)fluorenyl)zirconium dichloride, cycloheptylidene
(cyclopentadienyl)(2,7-di(trimethylsilyl)fluorenyl)-zirconium
dichloride,
cyclopropylidene(cyclopentadienyl)-(2,7-diphenylfluorenyl)zirconium
dichloride, cyclobutylidene (cyclopentadienyl)
(2,7-diphenylfluorenyl)zir- conium dichloride,
cyclopentylidene(cyclopentadienyl)(2,7-diphenylfluoreny-
l)zirconium dichloride,
cyclohexylidene(cyclopentadienyl)(2,7-diphenylfluo- renyl)zirconium
dichloride, cycloheptylidene(cyclopentadienyl)(2,7-dipheny-
lfluorenyl)zirconium dichloride,
cyclodimethylenesilylene(cyclopentadienyl-
)(2,7-di-tert-butylfluorenyl)zirconium dichloride,
cyclotrimethylenesilyle-
ne(cyclopentadienyl)(2,7-di-tert-butylfluorenyl)zirconium
dichloride,
cyclotetamethylenesilylene(cyclopentadienyl)(2,7-di-tert-butylfluorenyl)z-
irconium dichloride,
cyclopentamethylenesilylene(cyclopentadienyl)(2,7-di--
tert-butylfluorenyl)zirconium dichloride,
cycloheptamethylenesilylene(cycl-
opentadienyl)(2,7-di-tert-butylfluorenyl)zirconium dichloride,
cyclodimethylenesilylene(cyclopentadienyl)(3,6-di-tert-butylfluorenyl)zir-
conium dichloride,
cyclotrimethylenesilylene(cyclopentadienyl)(3,6-di-tert-
-butylfluorenyl)zirconium dichloride,
cyclotetramethylenesilylene(cyclopen-
tadienyl)-(3,6-di-tert-butylfluorenyl)zirconium dichloride,
cyclopentamethylenesilylene(cyclopentadienyl)(3,6-di-tert-butyl-fluorenyl-
)zirconium dichloride,
cyclopentamethylenesilylene(cyclopentadienyl)(3,6-d-
i-tert-butylfluorenyl)zirconium dichloride,
cyclodimethylenesilylene(cyclo-
pentadienyl)(2,7-di(trimethylsilyl)fluorenyl)zirconium dichloride,
cyclotrimethylenesilylene(cyclopentadienyl)(2,7-di(trimethylsilyl)fluoren-
yl)zirconium dichloride,
cyclotetramethylenesilylene(cyclopentadienyl)(2,7-
-di(trimethylsilyl)fluorenyl)zirconium dichloride,
cyclopentamethylenesily-
lene(cyclopentadienyl)(2,7-di(trimethylsilyl)fluorenyl)zirconium
dichloride,
cycloheptamethylenesilylene(cyclopentadienyl)(2,7-di(trimethy-
lsilyl)fluorenyl)zirconium dichloride,
cyclodimethylenesilylene(cyclopenta-
dienyl)(2,7-diphenyl-fluorenyl)zirconium dichloride,
cyclotrimethylenesilylene(cyclopentadienyl)(2,7-diphenylfluorenyl)zirconi-
um dichloride,
cyclotetramethylenesilylene(cyclopentadienyl)(2,7-diphenylf-
luorenyl)zirconium dichloride,
cyclopentamethylenesilylene(cyclopentadieny-
l)(2,7-diphenylfluorenyl)zirconium dichloride and
cycloheptamethylenesilyl-
ene(cyclopentadienyl)(2,7-diphenylfluorenyl)zirconium
dichloride.
[0041] In addition, the metallocene compounds of the present
invention also include metallocene compounds in which a part or all
of the chlorine atoms are replaced with other substituents.
Examples of such metallocene compounds include a metallocene
compound in which chlorine is replaced with bromine, iodine or
fluorine, a metallocene compound in which the halogen is replaced
with an alkyl group such as a methyl group, a metallocene compound
in which the halogen is replaced with trimethylphosphine, a
metallocene compound in which the halogen is replaced with an
alkoxy group such as a methoxy group, and a metallocene compound
which is coordinated with THF.
[0042] In addition, the present invention can cover the
above-mentioned metallocene compounds in which zirconium is
replaced with titanium or hafnium.
[0043] Examples of the olefin, which is to be polymerized in the
presence of the catalytic system including the metallocene compound
represented by the formula [1] in the present invention, include
a-olefins (inclusive of ethylene) having 2 to 20 carbon atoms,
preferably .alpha.-olefins having 2 to 10 carbon atoms. Typical
examples of the olefins include ethylene, propylene, 1-butene,
3-methyl-1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene,
vinylcyclohexane and styrene.
[0044] In this invention, moreover, the olefins further include
dienes having 4 to 20 carbon atoms such as butadiene,
1,4-pentadiene, 1,5-hexadiene and 1,4-hexadiene.
[0045] In addition, the olefins in this invention further include
cyclic olefins such as dicyclopentadiene, norbornene,
methylnorbornene, tetracyclododecene and methyltetracyclododecene,
and silicon-containing olefins such as allyltrimethylsilane and
vinyltrimethylsilane.
[0046] These olefins may be homopolymerized singly or copolymerized
in a combination of two or more thereof.
[0047] In the present invention, there can be used a cocatalyst
which is usually used as an olefin polymerization catalyst together
with the metallocene compound.
[0048] In the present invention, as an organic aluminoxane which
can be used together for the polymerization of the olefin by the
use of the metallocene compound represented by the formula [1],
there can be used a compound represented by the formula [4] or [5]
5
[0049] wherein R.sup.3 may be the same or different, and it is an
alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to
18 carbon atoms, or hydrogen; and p is an integer of 2 to 50,
preferably 10 to 35.
[0050] In the polymerization of the olefin, a use ratio of the
organic aluminoxane represented by the formula [4] or [5] to the
metallocene compound represented by the formula [1] is usually such
that a molar ratio of aluminum/the metallocene compound is in the
range of 1 to 10,000.
[0051] In the case that the above-mentioned organic aluminoxane is
used, an organic aluminum compound having 1 to 20 carbon atoms can
be used together, and in this case, the employment of a relatively
small amount of the aluminoxane permits obtaining a good
performance. A use ratio of the organic aluminum compound to the
metallocene compound represented by the formula [1] is usually such
that a molar ratio of aluminum/the metallocene compound is in the
range of 1 to 10,000.
[0052] Examples of such an organic aluminum compound include
trimethyl aluminum, triethyl aluminum, tripropyl aluminum,
triisopropyl aluminum, tri-n-butyl aluminum, triisobutyl aluminum,
tri-sec-butyl aluminum, dimethyl aluminum chloride, diethyl
aluminum chloride, dipropyl aluminum chloride, diisopropyl aluminum
chloride, di-n-butyl aluminum chloride, diisobutyl aluminum
chloride and di-sec-butyl aluminum chloride.
[0053] Furthermore, the metallocene compound represented by the
formula [1] and the organic aluminoxane represented by the formula
[4] or [5] which can be used in the present invention, when used,
may be brought into contact with a carrier which is insoluble in an
inert organic solvent of a hydrocarbon such as pentane, hexane,
heptane, benzene or toluene.
[0054] Examples of the usable carrier include inorganic oxides and
organic polymer which are insoluble in an inert organic solvent
having a functional group.
[0055] In the present invention, as the inorganic oxide which can
be used in the preparation of a solid catalyst component obtained
by bringing the organic aluminoxane represented by the formula [4]
or [5] or the methallocene compound into contact with the inorganic
oxide, there can be preferably utilized an oxide having voids
therein or an oxide having relatively large pores and hence a large
surface area.
[0056] Examples of the oxide include SiO.sub.2, Al.sub.2O.sub.3,
CaO, Na.sub.2O, K.sub.2O, MgO, MnOm (m is 1 or 2), TiO.sub.2 and
ZrO.sub.2. In addition, hollow inorganic oxides and gels of oxides
can also be utilized.
[0057] In general, the diameter of the inorganic oxide is
preferably in the range of about 1 .mu.m to about 0.1 mm.
[0058] Above all, an oxide including silica gel or alumina is
preferable, because such a kind of oxide permits a large amount of
the organic aluminoxane to be supported thereon.
[0059] Usually, the inorganic oxide is previously calcined before
brought into contact with the organic aluminoxane, and the thus
dried inorganic oxide is then used. However, the anhydrous
inorganic oxide including 10% by weight or less of adsorbed water
is also acceptable.
[0060] The above-mentioned solid catalyst component can be obtained
by bringinging the organic aluminoxane for use in the present
invention into contact with the inorganic oxide. That is to say,
concretely, the solid catalyst component can be obtained by
suspending the inorganic oxide in an alkane, an aromatic
hydrocarbon, an ether or a halogenated hydrocarbon which is an
organic solvent inert to the organic aluminoxane, and then mixing
the resultant suspension with the organic aluminoxane at a
temperature of 50 to 200.degree. C.
[0061] In this case, the contact amount of the organic aluminoxane
is at least in excess of a predetermined amount of the organic
aluminoxane to be supported on the inorganic oxide, and it is 1.5
times or more, preferably twice or more as much as the
predetermined amount of the organic aluminoxane. If this amount of
the organic aluminoxane is less than 1.5 times, the sufficiently
catalytic activity cannot be obtained inconveniently.
[0062] After the organic aluminoxane has been brought into
contacted with the inorganic oxide, the unreacted organic
aluminoxane is separated from the obtained solid catalyst
component. No particular restriction is put on a technique for this
separation, but there can be utilized usual filtration or
decantation in which a supernatant obtained by still standing is
removed. The thus separated solid catalyst component may be further
washed with an inert organic solvent, as needed.
[0063] Alternatively, the organic aluminoxane represented by the
formula [4] or [5] in the present invention can be brought into
contact with an organic polymer having a functional group to
prepare the solid catalyst component, but examples of the
functional group contained in this organic polymer include
aldehyde, carboxyl, ketones, carboxycarbonyls (dicarboxylic
anhydrides), esters, halogenated carbonyls, amides and imides.
[0064] Furthermore, as the organic polymer having the functional
group which can be used in the present invention, there can be
utilized the following polymer (1), (2) and (3).
[0065] (1) A polymer obtained by (co)polymerizing a monomer(s)
having the functional group.
[0066] (2) A polymer obtained by grafting or graft-polymerizing a
monomer having the functional group to a polymer having no
functional group.
[0067] (3) A polymer obtained by modifying a polymer with a
compound having the functional group or a precursor of the
functional group.
[0068] These polymer will be described in more detail. Examples of
the monomer having the functional group for use in the
polymerization of the organic polymer of the above-mentioned (1)
include, but are not limited to, acrylic acids such as methacrylic
acid and arcrylic acid; acrylates such as methyl methacrylate and
methyl acrylate; acrylamides such as methacrylamide, acrylamide and
crotonamide; vinyl compounds such as vinyl acetate, methylvinyl
ketone, acryloyl chloride and acrylaldehyde; lactones such as
.beta.-propiolactone; lactams such as .di-elect cons.-caprolactam;
isocyanates such as tetramethylene diisocyanate, hexamethylene
diisocyanate and octamethylene diisocyanate; N-carboxyamino acid
anhydrides such as .beta.-benzylaspartic anhydride and
4-benzyloxazolid-2,5-dione; amonocarboxylic acids such as .di-elect
cons.-aminocaproic acid and .omega.-aminoundecanoic acid;
carboxylic anhydrides such as maleic anhydride, itaconic anhydride,
phthalic anhydride and pyromellitic anhydride; amines such as
hexamethylenediamine, nonamethylenediamine and phenylenediamine;
dicarboxylic acids such as adipic acid, maleic acid and itaconic
acid; halofolmylic acids such as adipic acid dichloride and
phthalic acid dichloride; esters such as dimethyl terephthalate;
and alcohols and phenols such as ethylene glycol, propylene glycol,
butanediol, hexamethylene glycol and bisphenol A.
[0069] The organic polymer of the above-mentioned (1) can be
obtained by subjecting one of these monomers or a combination of
two or more thereof, or a combination of any of the above-mentioned
monomers and a monomer having no functional group, to
polymerization or copolymerization such as radical polymerization,
cationic polymerization, anionic polymerization, transition metal
catalytic polymerization, ring opening polymerization, polyaddition
reaction, addition condensation reaction or polycondensation
reaction.
[0070] Examples of the monomer having no functional group include
.alpha.-olefins, styrenes, epoxy group-containing monomers and
ether group-containing monomers.
[0071] The organic polymer of the above-mentioned (2) obtained by
grafting or graft-polymerizing the monomer having the functional
group is an organic polymer obtained by grafting or
graft-polymerizing a dicarboxylic acid or the like to a polymer
having no functional group in accordance with a reaction such as
radical reaction or the Friedel-Crafts reaction.
[0072] Examples of the above-mentioned polymer having no functional
group include polyethylene, polypropylene, ethylene-propylene
copolymer, polybutene, ethylene-butene copolymer,
ethylene-propylene-butene copolymer, polyisobutene, polypentene,
poly(4-methylpentene) , polynorbornene, polybutadiene,
polyisoprene, polystyrene, poly(.alpha.-methylstyrene),
polyethylene oxide, polypropylene oxide, polytetrahydrofuran and
polysiloxane.
[0073] The above-mentioned polymer can be obtained by grafting or
graft-polymerizing, for example, any of acrylic acids such as
methacrylic acid and acrylic acid; acrylates such as methyl
methacrylate, 3-methacryloxypropyl-trimethoxysilane and methyl
acrylate; acrylamides such as methacrylamide, acrylamide and
crotoneamide; vinyl compounds such as vinyl acetate, methyl vinyl
ketone, acryloyl chloride and acrylaldehyde; haloformyls such as
acetyl chloride, adipic acid dichloride and phthalic acid
dichloride; carboxylic anhydrides such as acetic anhydride, maleic
anhydride and itaconic anhydride; and dicarboxylic acids such as
maleic acid and itaconic acid, to a polymer having no functional
group in accordance with the radical reaction, the Friedel-Crafts
reaction or the like.
[0074] Furthermore, the polymer (3) obtained by modifying the
polymer with the compound having the functional group or the
precursor of the functional group is a partially modified organic
polymer obtained by subjecting a polymer such as polyvinyl alcohol,
polyvinyl chloride, polyvinylpyridine, nitrated polystyrene,
polyacrylonitrile or cellulose to a reaction such as esterification
reaction, oxidation reaction, reduction reaction or acylation
reaction.
[0075] Preferable examples of the above-mentioned organic polymer
having the functional group include polyolefins such as
polyethylene and polypropylene obtained by grafting or
graft-polymerizing maleic anhydride, itaconic anhydride,
methacrylic acid, acrylic acid, methyl methacrylate and methyl
acrylate in accordance with radical reaction.
[0076] In particular, grafted or graft polymerized polyolefins such
as polyethylene and polypropylene obtained by grafting maleic
anhydride are preferable because of easy synthesis.
[0077] As techniques for preparing the solid catalyst component by
bringing the organic aluminoxane into contact with the organic
polymer having the functional group for use in the present
invention, there are the following methods (I), (II) and (III).
[0078] (I) A method of bringing the organic aluminoxane into
contact with the organic polymer having the functional group
dissolved in a heated inert organic solvent.
[0079] (II) A method of bringing the organic aluminoxane into
contact with the organic polymer having the functional group
suspended in an inert organic solvent.
[0080] (III) A method of bringing the organic aluminoxane into
contact with the powdery organic polymer having the functional
group.
[0081] The inert organic solvent which can be used here is an
alkane, an aromatic hydrocarbon, an ether or a halogenated
hydrocarbon compound, and it is preferably an alkane having 1 to 20
carbon atoms, an aromatic hydrocarbon compound having 6 to 20
carbon atoms, an ether having 2 to 20 carbon atoms, or a
halogenated hydrocarbon having 1 to 20 carbon atoms. Typical
examples of the alkane include pentane, heptane, octane, isobutane,
neopentane, cyclopentane and decalin; examples of the aromatic
hydrocarbon compound include benzene, toluene and xylene; examples
of the ether include diethyl ether, tetrahydrofuran,
1,2-dimethoxyethane and dioxane; and examples of the halogenated
hydrocarbon include dichloromethane and chloroform. Moreover, the
inert organic solvent may be a mixture of some of these
compounds.
[0082] In the method of the above-mentioned (I), the organic
polymer having the functional group, which is insoluble in an
inactive organic solvent at room temperature, is heated and
dissolved in the inert organic solvent at a temperature of
40.degree. C. to 250.degree. C., preferably 60.degree. C. to
200.degree. C., and the resultant solution is then mixed with the
organic aluminoxane, whereby both the components can be brought
into contact with each other.
[0083] Then, a poor solvent is added to the solution which has been
subjected to the contact treatment, thereby causing precipitation,
and the resultant precipitate is collected by filtration. If
necessary, the precipitate may be washed with a solvent prior to
its use. The solvent is removed therefrom, and the precipitate may
further be pulverized by a vibration mill, a ball mill or the
like.
[0084] In the method of the above-mentioned (II), the organic
polymer having the functional group is suspended in the inert
organic solvent, and the resultant suspension is mixed with the
organic aluminoxane at a temperature of -80.degree. C. to
200.degree. C., preferably -20.degree. C. to 150.degree. C.,
whereby both the components can be brought into contact with each
other. The suspension may then be washed prior to its use.
Afterward, a poor solvent may be added to the suspension which has
been subjected to the contact treatment, and it may be then
used.
[0085] Furthermore, the solvent may be removed from the suspension,
and the solvent-free suspension is then pulverized by a vibration
mill, a ball mill or the like prior to its use.
[0086] In the method of the above-mentioned (III), the powdery
organic polymer having the functional group may be mixed with the
organic aluminoxane substantially in the absence of any solvent at
a temperature of -80.degree. C. to 200.degree. C., or preferably
-20.degree. C. to 150.degree. C. by a mixing machine or a
pulverizer such as a mixer or a mill, whereby these materials can
be brought into contact with each other, and this mixture may be
then used. The powder thus obtained may further be suspended in a
poor solvent.
[0087] Moreover, the solid catalyst component obtained by any of
the above-mentioned methods (I) to (III) which can be used in the
present invention may be washed with an inert organic solvent as
occasion demands.
[0088] A contact amount ratio between the organic aluminoxane and
the organic polymer obtained by any of the above-mentioned methods
(I) to (III) which can be used in the present invention is such
that a mol number of aluminum contained in the organic aluminoxane
is in the range of 1.times.10.sup.-5 to 0.1 mol, preferably
1.times.10.sup.-4 to 0.01 mol with respect to 1 g of the organic
polymer.
[0089] The organic polymer contains the functional group for use in
the synthesis of the solid catalyst component.
[0090] In the present invention, the ratio of the organic
aluminoxane represented by the formula [4] or [5], or the solid
catalyst component with respect to the metallocene compound
represented by the formula [1] is such that a mol number
(aluminum/a transition metal) of aluminum contained in the organic
aluminoxane or the organic aluminoxane present in the solid
catalyst component with respect to a mol number of the transition
metal in the metallocene compound is in the range of 1 to 10000,
preferably 10 to 2000.
[0091] The solid catalyst component can be obtained by bringing the
organic aluminoxane into contact with the organic polymer having
the functional group, or alternatively by bringing the organic
aluminoxane into contact with an inorganic oxide.
[0092] When the olefin is polymerized with the metallocene compound
represented by the formula [1] in the present invention, the
metallocene compound to be used may be converted into a cationic
compound, and an ionic compound which can produce a stable paired
anionic species may be used. In this case, an organic aluminum
compound is preferably used together.
[0093] Typical examples of the ionic compound include carbenium
boranes, metal boranes and ammonium borans such as
triphenylcarbeniumtetrakis(pent- afluorophenyl) borate,
ferroceniumtetrakis(pentafluorophenyl) borate,
N,N-dimethyl-ammoniumtetrakis(pentafluorophenyl) borate,
tri-n-butyl-ammoniumtetrakis(pentafluorophenyl) borate,
triethylammoniumtetrakis(phenyl) borate and
tri-n-butylammoniumtetra(phen- yl) borate.
[0094] In addition, for example, compounds exemplified in Japanese
PCT Patent Application Laid-Open Nos. 501950/1989 and 502036/1989
can also be used.
[0095] The molar ratio of the ionic compound with respect to the
metallocene compound is such that the ionic compound/the
metallocene compound is in the range of 0.1 to 10.
[0096] Furthermore, the above-mentioned organic aluminum compound
which can be used herein has 1 to 20 carbon atoms, and examples of
the organic aluminum compound include trimethylaluminum,
triethylaluminum, tripropylaluminum, triisopropylaluminum,
tri-n-butylaluminum, triisobutylaluminum, tri-sec-butylaluminum,
dimethylaluminum chloride, diethylaluminum chloride,
dipropylaluminum chloride, diisopropylaluminum chloride,
di-n-butylaluminum chloride, diisobutylaluminum chloride and
di-sec-butylaluminum chloride.
[0097] The molar ratio of the organic aluminum compound with
respect to the metallocene compound is such that the organic
aluminum compound/the metallocene compound is in the range of 1 to
10,000.
[0098] In the present invention, the polymerization of the olefin
can be carried out by any of a usual solvent polymerization, a bulk
polymerization and a gaseous phase polymerization. A polymerization
temperature is usually in the range of -100 to 200.degree. C.,
preferably -20 to 100.degree. C., and no particular restriction is
put on a polymerization pressure, but the preferable polymerization
pressure is in the range of atomospheric pressure to 5 MPa gauge
pressure. In the polymerization, hydrogen can be added to the
polymerization system in order to decrease the molecular weight of
the produced polymer, and the amount of hydrogen depends on the
molecular weight of the desired polymer, but it is suitably in the
range of 0.01 to 20 NL per kg of the olefin. The molecular weight
of the polyolefin obtained by the present invention is preferably
in the range of 1,000 to 100,000, more preferably 5,000 to 50,000,
most preferably 5,000 to 40,000 in terms of a molecular weight Mw
by GPC.
[0099] The practice of the process according to the present
invention permits the preparation of a polyolefin having a high
stereoregularity and a low molecular weight, and hence the process
is industrially extremely valuable.
[0100] Next, the present invention will be described in detail in
accordance with examples, but the scope of the present invention
should not be limited to these examples at all.
EXAMPLE 1
[0101] [Synthesis of a metallocene compound]
(1) Cyclohexylfulvene
[0102] 8.2 ml (100 mmol) of cyclopentadiene and 4.2 ml (40 mmol) of
cyclehexanone were added to 40 ml of dehydrated methanol, and 5.0
ml (60 mmol) of pyrrolidine were then added dropwise at 0.degree.
C. Then, reaction was carried out at room temperature for 3 hours.
Next, 3.8 ml of acetic acid were slowly added at 0.degree. C., and
20 ml of water were further added, followed by extraction with
diethyl ether. The resultant organic phase, after washed with
water, was dried over magnesium sulfate, and the used solvent was
then distilled off to obtain 5.95 g of a yellow liquid.
[0103] .sup.1H-NMR spectrum (90 MHz, CDCl3) .delta.6.50(4H),
2.60(4H), 1.66(6H)
(2)
1-cyclopentadienyl-1-(2,7-di-tert-butylfluorenyl)cyclohexane
[0104] To a THF (30 ml) solution including 5.0 g (18.6 mmol) of
2,7-di-tert-butylfluorene, a hexane solution (13.5 ml, 21.6 mmol)
of n-butyllithium was added dropwise at -78.degree. C. under
nitrogen, followed by stirring at room temperature for 6 hours.
Next, a THF (20 ml) solution including 3.42 g (23.4 mmol) of
cyclohexylfulvene was added dropwise at 0.degree. C. under a
nitrogen atmosphere, followed by stirring at room temperature for
16 hours. The resultant reaction solution was decomposed with cold
water, and then extracted with ether. The extract was dried over
magnesium sulfate and then filtered, and the used solvent was
removed from the filtrate under reduced pressure, thereby obtaining
a solid. This solid was recrystallized from methanol to obtain 5.36
g of a colorless solid.
[0105] .sup.1H-NMR spectrum (270 MHz, CDCl3) .delta.7.53(2H),
7.35-7.15(4H), 6.65-6.35, 5.93(3H), 3.91, 3.87(1H), 3.07, 2.92(2H),
1.90-0.90(10H), 1.32(18H)
(3)
Cyclohexylidene(cyclopentadienyl)(2,7-di-tert-butylfluorenyl)zirconium
dichloride
[0106] 5.8 ml (5.8 mmol) of a diethyl ether solution of
methyllithium were added dropwise under ice cooling under nitrogen
to a THF (20 ml) solution including 1.0 g (2.36 mmol) of
1-cyclopentadienyl-1-(2,7-di-tert-butylflu- orenyl)cyclohexane
synthesized in the above-mentioned (2), followed by stirring at
room temperature for 7 hours. Next, the THF was distilled off under
nitrogen, and the resultant solid was washed with hexane and then
dissolved in dichloromethane cooled to -78.degree. C. To this
solution, zirconium tetrachloride 2THF complex (0.81 g, 2.15 mmol)
dissolved in dichloromethane was added at -78.degree. C., and after
stirring for 24, the temperature of the solution was slowly
returned to room temperature.
[0107] Furthermore, this solution was filtered through cerite, and
the resultant filtrate was concentrated to remove the solvent,
followed by cooling at -30.degree. C. The precipitated solid was
washed with pentane, and then dried under reduced pressure to
obtain 90 mg of a red solid.
[0108] .sup.1H-NMR spectrum (270 MHz, CDCl3) .delta.8.02(2H),
7.65(2H), 7.63(2H), 6.30(2H), 5.65(2H), 3.40-3.30(2H),
2.36-1.66(8H), 1.34(18H)
[0109] The .sup.1H-NMR spectrum of the obtained metallocene
compound is shown in FIG. 1.
[0110] FD-MS spectrum m/z=582-590 (M.sup.+) According to this
spectrum, and FD-MS spectrum it was confirmed that the obtained
compound was the desired metallocene compound.
EXAMPLE 2
[0111] In a 5-liter autoclave sufficiently purged with nitrogen
were placed a toluene solution including 1.7 mg of a red solid
obtained in Example 1 and methylaluminoxane (made by Albemal Co.,
Ltd.) in an amount of 25 mmol in terms of aluminum, and
polymerization was then carried out at 70.degree. C. for 1 hour in
the presence of 0.325 NL of hydrogen and 1.5 kg of propylene. After
the polymerization, propylene was purged, and the resultant polymer
was dried at 80.degree. C. for 6 hours under reduced pressure. The
amount of the thus obtained polymer was 485 g, and its intrinsic
viscosity [.eta.] in tetralin at 135.degree. C. was 0.504 dl/g. The
molecular weight (Mw) by GPC was 36.200. The melting point (Tm) of
the polymer by DSC was 138.degree. C., and it was confirmed from
the analytical results of infrared spectrum (IR) that the obtained
polymer was a syndiotactic polypropylene.
EXAMPLE 3
[0112] The polymerization of propylene was carried out by the same
procedure as in Example 2 except that methylaluminoxane in an
amount of 25 mmol in terms of aluminum in Example 2 was replaced
with 11 mg of triphenylcarbeniumtetrakis(pentafluorophenyl) borate
and 128 mg of triisobutylaluminum. A polymer was obtained in an
amount of 450 g, and it had [.eta.]=0.51 dl/g, Tm=138.degree. C.,
and Mw by GPC was 37,000 and it was confirmed from the analytical
results of IR that the obtained polymer was a syndiotactic
polypropylene.
EXAMPLE 4
[0113] The polymerization of propylene was carried out by the same
procedure as in Example 2 except that, in place of
methylaluminoxane in an amount of 25 mmol in terms of aluminum in
Example 2, 1.7 mg of a metallocene compound used in Example 1 were
supported on 90 mg of a solid component obtained by bringing 0.75 g
of methylaluminoxane into contact with 1 g of 10 wt % maleic
anhydride graft PP dissolved in xylene at 120.degree. C., adding
heptane to the mixture to cause precipitation, filtering, drying
and then grinding; and 128 mg of triisobutylaluminum were used. The
supporting procedure used here is disclosed in Japanese Patent
Application Laid-open NO. 309911/1997.
[0114] A polymer was obtained in an amount of 545 g, and it had
[.eta.]=0.50 dl/g, and Tm=134.degree. C. and Mw by GPC was 36,000
and it was confirmed from the analytical results of IR that the
obtained polymer was a syndiotactic polypropylene.
Comparative Example 1
[0115] The polymerization of propylene was carried out by the same
procedure as in Example 2 except that
cyclohexylidene(cyclopentadienyl)(2-
,7-di-tert-butylfluorenyl)zirconium dichloride obtained in Example
1 was replaced with 0.82 mg of
dimethylmethylene(cyclopentadienyl)(2,7-di-tert--
butylfluorenyl)zirconium dichloride.
[0116] A polymer was obtained in an amount of 570 g, and it had
[.eta.]=0.68 dl/g, Tm=136.degree. C. and Mw by GPC was 52,000 and
it was confirmed from the analytical results of IR that the
obtained polymer was a syndiotactic polypropylene.
Comparative Example 2
[0117] [Synthesis of a metallocene compound]
(1) 1-Cyclopentadienyl-1-(fluorenyl)cyclohexane
[0118] A hexane solution (20 ml, 32 mmol) of n-butyllithium was
added dropwise to a THF (40 ml) solution including 5.0 g (30 mmol)
of fluorene under nitrogen at -78.degree. C., followed by stirring
at room temperature for 6 hours.
[0119] Next, a THF (20 ml) solution including 5.8 g (39.7 mmol) of
cyclohexylfulvene was added dropwise to the solution under a
nitrogen atmosphere, followed by stirring at room temperature for
16 hours.
[0120] The resultant reaction solution was decomposed with cold
water, and then extracted with ether. The extract was dried over
magnesium sulfate and then filtered, and the used solvent was
removed from the filtrate under reduced pressure, thereby obtaining
a solid.
[0121] This solid was recrystallized from methanol to obtain 7.58 g
of a colorless solid.
[0122] .sup.1H-NMR spectrum (90 MHz, CDCl3) .delta.7.65(2H),
7.39-7.13(6H), 6.45, 5.84 (3H), 3.94(1H), 2.98, 2.70(2H),
2.00-1.15(10H)
(2) Cyclohexylidene(cyclopentadienyl)(fluorenyl)zirconium
dichloride
[0123] A hexane solution (2.3 ml, 4.6 mmol) of n-butyl-lithium was
added dropwise under ice cooling under nitrogen to a THF (20 ml)
solution including 1-cyclopentadienyl-1-(fluorenyl)cyclohexane (0.5
g, 1.6 mmol) synthesized in the above-mentioned (1), followed by
stirring at room temperature for 7 hours.
[0124] Next, the THF was distilled off under nitrogen, and the
resultant solid was washed with hexane and then dissolved in
dichloromethane cooled to -78.degree. C.
[0125] To this solution, zirconium tetrachloride 2THF complex (0.81
g, 2.15 mmol) dissolved in dichloromethane was added at -78.degree.
C., and after stirring for 24, the temperature of the solution was
slowly returned to room temperature.
[0126] Furthermore, this solution was filtered through cerite, and
the resultant filtrate was concentrated to remove the solvent,
followed by cooling at -30.degree. C. The precipitated solid was
washed with pentane, and then dried under reduced pressure to
obtain 65 mg of a red solid.
[0127] .sup.1H-NMR spectrum (90 MHz, CDCl3) .delta.8.16(2H),
7.84-7.21(6H), 6.33(2H), 5.76(2H), 3.39-3.26(2H), 2.36-1.98(8H)
[0128] [Polymerization]
[0129] In a 5-liter autoclave sufficiently purged with nitrogen
were placed a toluene solution including 1.7 mg of
cyclohexylidene(cyclopentad- ienyl)(fluorenyl)zirconium dichloride
obtained in Comparative Example 3 and methylaluminoxane (made by
Albemal Co., Ltd.) in an amount of 25 mmol in terms of aluminum,
and polymerization was then carried out at 70.degree. C. for 1 hour
in the presence of 0.325 NL of hydrogen and 1.5 kg of
propylene.
[0130] After the polymerization, propylene was purged, and the
resultant polymer was dried at 80.degree. C. for 6 hours under
reduced pressure.
[0131] This polymer was obtained in an amount of 310 g, and its
intrinsic viscosity [.delta.] in tetralin at 135.degree. C. was
0.77 dl/g and Mw by GPC was 56,000. The melting point (Tm) of the
polymer by DSC was 135.degree. C., and it was confirmed from the
analytical results of infrared spectrum (IR) that the obtained
polymer was a syndiotactic polypropylene.
* * * * *