U.S. patent application number 09/446191 was filed with the patent office on 2002-10-24 for process for the preparation of copolymers of ethylene with alpha-olefins.
Invention is credited to DALL'OCCO, TIZIANO, RESCONI, LUIGI.
Application Number | 20020156209 09/446191 |
Document ID | / |
Family ID | 8233628 |
Filed Date | 2002-10-24 |
United States Patent
Application |
20020156209 |
Kind Code |
A1 |
DALL'OCCO, TIZIANO ; et
al. |
October 24, 2002 |
PROCESS FOR THE PREPARATION OF COPOLYMERS OF ETHYLENE WITH
ALPHA-OLEFINS
Abstract
Ethylene based copolymers having high molecular weights, narrow
molecular weight distributions, and a very good homogeneous
distribution of the comonomer units can be obtained in high yields
at temperatures of industrial interest, by carrying out the
polymerization reaction in the presence of metallocene catalysts
comprising particular bridged bis-indenyl compounds substituted in
the 3-position on the indenyl groups.
Inventors: |
DALL'OCCO, TIZIANO;
(FERRARA, IT) ; RESCONI, LUIGI; (FERRARA,
IT) |
Correspondence
Address: |
MAURICE B STIEFEL
BRYAN CAVE
245 PARK AVENUE
NEW YORK
NY
10167
|
Family ID: |
8233628 |
Appl. No.: |
09/446191 |
Filed: |
December 17, 1999 |
PCT Filed: |
April 13, 1999 |
PCT NO: |
PCT/EP99/02644 |
Current U.S.
Class: |
526/160 ;
526/159; 526/348.2; 526/348.5; 526/348.6 |
Current CPC
Class: |
C08F 210/16 20130101;
C08F 4/65912 20130101; C08F 210/16 20130101; C08F 4/65927 20130101;
C08F 210/16 20130101; C08F 210/14 20130101; C08F 2500/01 20130101;
C08F 2500/03 20130101; C08F 2500/17 20130101; C08F 2500/20
20130101 |
Class at
Publication: |
526/160 ;
526/159; 526/348.2; 526/348.5; 526/348.6 |
International
Class: |
C08F 004/44 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 21, 1998 |
EP |
98201287.4 |
Claims
1. A process for the preparation of copolymers of ethylene,
comprising the polymerization reaction of ethylene with at least
one alpha-olefin, and optionally with one ore more polyenes, in the
presence of a catalyst obtainable by contacting: (A) a metallocene
compound of the formula (I): 5wherein substituents R.sup.1 are
hydrogen atoms or C.sub.1-C.sub.20-alkyl groups, substituents
R.sup.2 are CHR.sup.10R.sup.11, SiR.sup.12R.sup.13R.sup.14 or
GeR.sup.15R.sup.16R.sup- .17 groups, wherein: R.sup.10, R.sup.11,
R.sup.12, R.sup.15 are hydrogen atoms, C.sub.1-C.sub.20-alkyl,
C.sub.3-C.sub.20-cycloalkyl, C.sub.2-C.sub.20-alkenyl,
C.sub.6-C.sub.20-aryl, C.sub.7-C.sub.20-alkylar- yl or
C.sub.7-C.sub.20-arylalkyl radicals, optionally containing silicon
or germanium atoms; R.sup.13, R.sup.14, R.sup.16, R.sup.17 are
C.sub.1-C.sub.20-alkyl, C.sub.3-C.sub.20-cycloalkyl,
C.sub.2-C.sub.20-alkenyl, C.sub.6-C.sub.20-aryl,
C.sub.7-C.sub.20-alkylar- yl or C.sub.7-C.sub.20-arylalkyl
radicals, optionally containing silicon or germanium atoms; R.sup.3
and R.sup.4, same or different, are hydrogen atoms or
--CHR.sup.5R.sup.6 groups; R.sup.3 and R.sup.4 can form a ring
having 3 to 8 carbon atoms which can contain hetero atoms; R.sup.5
and R.sup.6, same or different, are hydrogen atoms,
C.sub.1-C.sub.20-alkyl, C.sub.3-C.sub.20-cycloalkyl,
C.sub.2-C.sub.20-alkenyl, C.sub.6-C.sub.20-aryl,
C.sub.7-C.sub.20-alkylaryl or C.sub.7-C.sub.20-arylalkyl radicals,
which can form a ring having 3 to 8 carbon atoms which can contain
hetero atoms; the R.sup.7 substituents, same or different, are a
C.sub.1-C.sub.20-alkyl, C.sub.3-C.sub.20-cycloal- kyl,
C.sub.2-C.sub.20-alkenyl, C.sub.6-C.sub.20-aryl,
C.sub.7-C.sub.20-alkylaryl or C.sub.7-C.sub.20-arylalkyl radical,
optionally containing silicon or germanium atoms; and optionally
two adjacent R.sup.7 substituents can form a ring comprising from 5
to 8 carbon atoms, n being an integer from 0 to 4; M is an atom of
a transition metal selected from those belonging to group 3, 4, 5,
6 or to the lanthanide or actinide groups in the Periodic Table of
the Elements (new IUPAC version), X, same or different, is a
monoanionic ligand, such as a hydrogen atom, a halogen atom, an
R.sup.8, OR.sup.8, OSO.sub.2CF.sub.3, OCOR.sup.8, SR.sup.8,
NR.sup.8.sub.2 or PR.sup.8.sub.2 group, wherein the substituents
R.sup.8 are a C.sub.1-C.sub.20-alkyl, C.sub.3-C.sub.20-cycloalkyl,
C.sub.2-C.sub.20-alkenyl, C.sub.6-C.sub.20-aryl,
C.sub.7-C.sub.20-alkylaryl or C.sub.7-C.sub.20-arylalkyl radical,
optionally containing silicon or germanium atoms; p is an integer
of from 0 to 3, being equal to the oxidation state of the metal M
minus two; and (B) an alumoxane and/or a compound capable of
forming an alkyl metallocene cation.
2. The process according to claim 1, wherein said alumoxane is
obtained by contacting water with an organo-aluminium compound of
formula AlR.sup.9.sub.3 or Al.sub.2R.sup.9.sub.6, wherein the
R.sup.9 substituents, same or different from each other, are
defined as R.sup.1.
3. The process according to claim 1, wherein the molar ratio
between the aluminium and water is in the range of 1:1 and
100:1.
4. The process according to any of claims 1 to 3, wherein said
alumoxane is MAO, TIBAO and TIOAO, and said organo-aluminium
compound is TIOA, TMA and/or TIBA.
5. The process according to claim 1, wherein the compound capable
of forming a metallocene alkyl cation is a compound of formula
Y.sup.+Z.sup.-, wherein Y.sup.+ is a Brnsted acid, able to give a
proton and to react irreversibly with a substituent X of the
metallocene of formula (1) and Z.sup.- is a compatible anion, which
does not coordinate, which is able to stabilize the active
catalytic species originating from the reaction of the two
compounds, and which is sufficiently liable to be able to be
removed from an olefinic substrate.
6. The process according to claim 5, wherein the anion Z.sup.-
comprises one or more boron atoms.
7. The process according to any of claims 1 to 6, wherein in the
metallocene compound of formula (I) the transition metal M is
selected from titanium, zirconium and hafiiium.
8. The process according to any of claims 1 to 7, wherein in the
metallocene compound of formula (I) the substituents R.sup.1 and
R.sup.7 are hydrogen atoms.
9. The process according to claim 8, wherein in the metallocene
compound of formula (I) the R.sup.2 substituents are carbon,
silicon or germanium atoms substituted with two alkyl, cycloalkyl,
aryl, alkylaryl or arylalkylgroups having 1 to 10 carbon atoms.
10. The process according to any of claims 1 to 9, wherein in the
metallocene compound of formula (I) the X substituents are chlorine
atoms or methyl groups.
11. The process according to any of claims 1 to 10, wherein the
metallocene compound of formula (I) is
methylene-bis(3-isopropyl-indenyl)- zirconium dichloride or
isopropylidene-bis(3-isopropyl-indenyl)zirconium dichloride.
12. The process according to any of claims 1 to 11, wherein said
process is carried out at a temperature comprised between -100 and
+100.degree. C. and at a pressure comprised between 0.5 and 100
bar.
13. The process according to any of claims 1 to 12, wherein the
molar ratio between the aluminium and the metal of the metallocene
compound is comprised between 10:1 and 20000:1.
14. The process according to any of claims 1 to 13, wherein the
alpha-olefin is selected from the group comprising propylene,
1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene,
1-decene and 1-dodecene.
15. The process according to any of claims 1 to 14, wherein the
alpha-olefin is 1-hexene.
16. The process according to any of claims 1 to 15, wherein said
process is used for the preparation of homo- and copolymers of
ethylene.
Description
[0001] The present invention relates to a process for the
preparation of copolymers of ethylene with alpha-olefins.
[0002] Metallocene compounds with two bridged cyclopentadienyl
groups are known as catalyst components for the homo- and
copolymerization reaction of olefins.
[0003] For example, U.S. Pat. No. 5,001,205 discloses the
preparation of copolymers of ethylene with alpha-olefins in the
presence of a catalytic system comprising a bis-cyclopentadienyl
compound of Zr, Ti and Hf and methylalumoxane (MAO) as cocatalyst.
The working examples describe the copolymerization of ethylene with
propylene in the presence of bridged or unbridged
(tetrahydroindenyl)zirconium dichloride.
[0004] Although the homogeneity of the alpha-olefm distribution in
the chain is improved with respect to copolymers obtained from
conventional titanium- or vanadium-based Ziegler-Natta type
catalysts, it is still not satisfactory and a further improvement
is highly desirable. Metallocene compounds having two
cyclopentadienyl moieties bridged by a single atom are also
known.
[0005] For example, PCT application WO 96/22995 discloses a class
of single carbon bridged metallocenes, and their use in catalysts
for the polymerization of olefins, particularly of propylene. The
class of metallocene compounds which is indicated as especially
suitable for use in propylene polymerizations is that of the
single-carbon-bridged bis-indenyls wherein the indenyl moieties are
substituted in the 3-position with carbon, silicon or germanium
atoms having three hydrocarbon substituents. Neither are reported
examples of copolymerizations of ethylene with an alpha-olefin, nor
is given any information about the properties of the obtainable
ethylene copolymers. Particularly, there are no data about the
comonomer distribution along the polymer chain.
[0006] It would be desirable to select catalysts capable of
yielding ethylene copolymers having an improved homogeneity of the
distribution of the comonomer units along the polymer chain. It has
now been unexpectedly found that it is possible to prepare
ethylene-based copolymers having high molecular weight, and in
which the distribution of the comonomer units in the polymeric
chain is extremely homogeneous, operating at temperatures of
industrial interest, by carrying out the polymerization reaction of
ethylene in the presence of metallocene catalysts comprising
particular single atom bridged bis-indenyl compounds substituted in
the 3-position on the indenyl group.
[0007] Therefore, according to a first aspect, the present
invention provides a process for the preparation of copolymers of
ethylene, comprising the polymerization reaction of ethylene with
at least one comonomer selected from alpha-olefin, cycloolefins and
polyenes, in the presence of a catalyst comprising the product
obtainable by contacting: (A) a metallocene compound of the formula
(I): 1
[0008] wherein
[0009] substituents R.sup.1 are hydrogen atoms or
C.sub.1-C.sub.20-alkyl groups,
[0010] substituents R.sup.2 are CHR.sup.10R.sup.11,
SiR.sup.12R.sup.13R.sup.14 or GeR.sup.15R.sup.16R.sup.17
groups,
[0011] wherein: R.sup.10, R.sup.11, R.sup.12, R.sup.15 are hydrogen
atoms, C.sub.1-C.sub.20-alkyl, C.sub.3-C.sub.20-cycloalkyl,
C.sub.2-C.sub.20-alkenyl, C.sub.6-C.sub.20-aryl,
C.sub.7-C.sub.20-alkylar- yl or C.sub.7-C.sub.20-arylalkyl
radicals, optionally containing silicon or germanium atoms;
[0012] R.sup.13, R.sup.14, R.sup.16, R.sup.17 are
C.sub.1-C.sub.20-alkyl, C.sub.3-C.sub.20-cycloalkyl,
C.sub.2-C.sub.20-alkenyl, C.sub.6-C.sub.20-aryl,
C.sub.7-C.sub.20-alkylaryl or C.sub.7-C.sub.20-arylalkyl radicals,
optionally containing silicon or germanium atoms;
[0013] R.sup.3 and R.sup.4, same or different, are hydrogen atoms
or --CHR.sup.5R.sup.6 groups;
[0014] R.sup.3 and R.sup.4 can form a ring having 3 to 8 carbon
atoms which can contain hetero atoms;
[0015] R.sup.5 and R.sup.6, same or different, are hydrogen atoms,
C.sub.1-C.sub.20-alkyl, C.sub.3-C.sub.20-cycloalkyl,
C.sub.2-C.sub.20-alkenyl, C.sub.6-C.sub.20-aryl,
C.sub.7-C.sub.20-alkylar- yl or C.sub.7-C.sub.20-arylalkyl
radicals, which can form a ring having 3 to 8 carbon atoms which
can contain hetero atoms;
[0016] the R.sup.7 substituents, same or different, are a
C.sub.1-C.sub.20-alkyl, C.sub.3-C.sub.20-cycloalkyl,
C.sub.2-C.sub.20-alkenyl, C.sub.6-C.sub.20-aryl,
C.sub.7-C.sub.20-alkylar- yl or C.sub.7-C.sub.20-arylalkyl radical,
optionally containing silicon or germanium atoms; and optionally
two adjacent R.sup.7 substituents can form a ring comprising from 5
to 8 carbon atoms, n being an integer from 0 to 4;
[0017] M is an atom of a transition metal selected from those
belonging to group 3, 4, 5, 6 or to the lanthanide or actinide
groups in the Periodic Table of the Elements (new IUPAC version),
X, same or different, is a monoanionic ligand, such as a hydrogen
atom, a halogen atom, an R.sup.8, OR.sup.8, OSO.sub.2CF.sub.3,
OCOR.sup.8, SR.sup.8, NR82 or PR.sup.8.sub.2 group, wherein the
substituents R.sup.8 are a C.sub.1-C.sub.20-alkyl,
C.sub.3-C.sub.20-cycloalkyl, C.sub.2-C.sub.20-alkenyl,
C.sub.6-C.sub.20-aryl, C.sub.7-C.sub.20-alkylaryl or
C.sub.7-C.sub.20-aryl-alkyl radical, optionally containing silicon
or germanium atoms;
[0018] p is an integer of from 0 to 3, being equal to the oxidation
state of the metal M minus two; and
[0019] (B) an alumoxane and/or a compound capable of forming an
alkyl metallocene cation.
[0020] The transition metal M is preferably selected from titanium,
zirconium and hafnium.
[0021] The X substituents are preferably chlorine atoms or methyl
groups.
[0022] The R.sup.1 and R.sup.7 substituents are preferably hydrogen
atoms.
[0023] Non-limiting examples of metallocene compounds suitable for
use in the process of the invention are:
[0024] methylene-bis(3-methyl-indenyl)zirconium dichloride and
dimethyl;
[0025] isopropylidene-bis(3-methyl-indenyl)zirconium dichloride and
dimethyl;
[0026] methylene-bis(3-ethyl-indenyl) zirconium dichloride and
dimethyl;
[0027] isopropylidene-bis(3-ethyl-indenyl)zirconium dichloride and
dimethyl;
[0028] methylene-bis(3-dimethylsilyl-indenyl)zirconium dichloride
and dimethyl;
[0029] isopropylidene-bis(3-dimethylsilyl-indenyl)zirconium
dichloride and dimethyl;
[0030] methylene-bis(3-dimethylgermyl-indenyl)zirconium dichloride
and dimethyl;
[0031] isopropylidene-bis(3-dimthylgermyl-indenyl)zirconium
dichloride and dimethyl;
[0032] methylene-bis(3-trimethylsilyl-indenyl)zirconium dichloride
and dimethyl;
[0033] isopropylidene-bis(3-trimethylsilyl-indenyl)zirconium
dichloride and dimethyl;
[0034] methylene-bis(3-triethylsilyl-indenyl)zirconium dichloride
and dimethyl;
[0035] isopropylidene-bis(3-triethylsilyl-indenyl)zirconium
dichloride and dimethyl;
[0036] methylene-bis(3-trimethylgermyl-indenyl)zirconium dichloride
and dimethyl;
[0037] isopropylidene-bis(3-trimethylgermyl-indenyl)zirconium
dichloride and dimethyl;
[0038] methylene-bis(3-diphenylsilyl-indenyl)zirconium dichloride
and dimethyl;
[0039] isopropylidene-bis(3-diphenylsilyl-indenyl)zirconium
dichloride and dimethyl;
[0040] methylene-bis(3-diethylsilyl-indenyl)zirconium dichloride
and dimethyl;
[0041] isopropylidene-bis(3-diethylsilyl-indenyl)zirconium
dichloride and dimethyl;
[0042] methylene-bis(2-methyl-3-trimethylsilyl-indenyl)zirconium
dichloride and dimethyl;
[0043]
isopropylidene-bis(2-methyl-3-trimethylsilyl-indenyl)zirconium
dichloride and dimethyl;
[0044] methylene-bis(2-methyl-3-diethylsilyl-indenyl)zirconium
dichloride and dimethyl;
[0045] isopropylidene-bis(2-methyl-3-diethylsilyl-indenyl)zirconium
dichloride and dimethyl;
[0046] methylene-bis(3-benzylsilyl-indenyl)zirconium dichloride and
dimethyl;
[0047] isopropylidene-bis(3-benzylsilyl.-indenyl)zirconium
dichloride and dimethyl;
[0048] methylene-bis(3-cyclopentylsilyl-indenyl)zirconium
dichloride and dimethyl;
[0049] isopropylidene-bis(3-cyclopentylsilyl-indenyl)zirconium
dichloride and dimethyl;
[0050] methylene-bis(2-ethyl-3-diethylsilyl-indenyl)zirconium
dichloride and dimethyl;
[0051] isopropylidene-bis(2-ethyl-3-diethylsilyl-indenyl)zirconium
dichloride and dimethyl.
[0052] In the metallocene compound of formula (I) in which R.sup.2
is a CHR.sup.10R.sup.11 group, preferably R.sup.10 is different
from a hydrogen atom. More preferably, both R.sup.10 and R.sup.11
are different from an hydrogen atom.
[0053] Particularly interesting metallocenes of formula (I) for use
in the process of the invention are those in which R.sup.1 is an
hydrogen atom and R.sup.2 is a CHR.sup.10R.sup.11 group.
[0054] Non-limiting examples belonging to this class are:
[0055] methylene-bis(3-isopropyl-indenyl)zirconium dichloride and
dimethyl;
[0056] isopropylidene-bis(3-isopropyl-indenyl)zirconium dichloride
and dimethyl;
[0057] methylene-bis(3-isobutyl-indenyl)zirconium dichloride and
dimethyl;
[0058] isopropylidene-bis(3-isobutyl-indenyl)zirconium dichloride
and dimethyl;
[0059] methylene-bis(3-isopentyl-indenyl)zirconium dichloride and
dimethyl;
[0060] isopropylidene-bis(3-isopentyl-indenyl)zirconium dichloride
and dimethyl;
[0061] methylene-bis(3-diphenylmethyl-indenyl)zirconium dichloride
and dimethyl;
[0062] isopropylidene-bis(3-diphenylmethyl-indenyl)zirconium
dichloride and dimethyl;
[0063] methylene-bis(3-biscyclohexylmethyl-indenyl)zirconium
dichloride and dimethyl;
[0064] isopropylidene-bis(3-biscyclohexylmethyl-indenyl)zirconium
dichloride and dimethyl.
[0065] Most preferably the metallocene compounds of formula (I) are
methylene-bis(3-isopropyl-indenyl)zirconium dichloride and
isopropylidene-bis(3-isopropyl-indenyl)zirconium dichloride.
[0066] The metallocene compounds of formula (I) can be prepared by
reaction of the corresponding indenyl ligands with a compound
capable of forming delocalized anion on the cyclopentadienyl ring,
and with a compound of formula MX.sub.p+2, wherein M, X and p are
defined as above.
[0067] The ligands of formula (I) can be prepared by different
methods. A particularly suitable method for preparing the ligands
of formula (I) wherein R.sup.3 and R.sup.4 are hydrogen atoms is
described in European Patent Application No. 97200933.6, in the
name of the same Applicant. A particularly suitable method for
preparing the ligands of formula (I) wherein the substituents
R.sup.3 and R.sup.4 are different from hydrogen atoms is described
in EP-A 0 722 949.
[0068] In the case in which at least one substituent X in the
metallocene compound of the formula (I) which is to be prepared is
other than a halogen, it is necessary to substitute at least one
substituent X in the metallocene obtained by at least one
substituent X other than a halogen. The reaction of substituting
substituents X by substituents X other than a halogen is carried
out using generally applied methods. For example, if the desired
substituents X are alkyl groups, the metallocenes can be made to
react with alkylmagnesium halides (Grignard reagents) or with
alkyllithium compounds.
[0069] In the catalyst used in the process according to the
invention, both the metallocene compound of the formula (I) and the
alumoxane can be present as the product of the reaction with an
organometallic aluminium compound of the formula AlR.sup.9.sub.3 or
Al.sub.2R.sup.9.sub.6, in which the R.sup.9 substituents, same or
different, are defined as the substituents R or are halogen atoms.
The alumoxanes used in the process of the present invention may be
obtained by contacting water with an organometallic compound of
aluminium of formula AlR.sup.9.sub.3 or Al.sub.2R.sup.9.sub.6, in
which the R.sup.9 substituents, same or different, are defined as
above, with the condition that at least one R.sup.9 is different
from halogen. The molar ratio between the aluminium and water is in
the range of 1:1 and 100:1.
[0070] Non-limiting examples of aluminium compounds of the formula
AlR.sup.9.sub.3 or Al.sub.2R.sup.9.sub.6 are:
[0071] Al(Me).sub.3, Al(Et).sub.3, AlH(Et).sub.2, Al(iBu).sub.3,
AlH(iBu).sub.2, Al(iHex).sub.3, Al(iOct).sub.3, AlH(iOct).sub.2,
Al(C.sub.6H.sub.5).sub.3, Al(CH.sub.2C.sub.6H.sub.5).sub.3,
Al(CH.sub.2CMe.sub.3).sub.3, Al(CH.sub.2SiMe.sub.3).sub.3,
Al(Me).sub.2iBu, Al(Me).sub.2Et, AlMe(Et).sub.2, AlMe(iBu).sub.2,
Al(CH.sub.2-CH(Me)CH(Me).sub.2).sub.3, Al(Me).sub.2iBu,
Al(Me).sub.2Cl, Al(Et).sub.2Cl, AlEtCl.sub.2 and
Al.sub.2(Et).sub.3Cl.sub.3, wherein Me=methyl, Et=ethyl,
iBu=isobutyl, iHex=isohexyl, iOct=2,4,4-trimethyl-pe- ntyl.
[0072] Amongst the above aluminium compounds, trimethylaluminium
(TMA), triisobutylaluminium (TIBAL) and
tris(2,4,4-trimethyl-pentyl)aluminium (TIOA) are preferred.
[0073] The alumoxanes used in the catalyst according to the
invention are considered to be linear, branched or cyclic compounds
containing at least one group of the type: 2
[0074] wherein the substituents R.sup.18, same or different, are
C.sub.1-C.sub.20-alkyl, C.sub.3-C.sub.20-cycloalkyl,
C.sub.2-C.sub.20-alkenyl, C.sub.6-C.sub.20-aryl,
C.sub.7-C.sub.20-alkylar- yl or C.sub.7-C.sub.20-arylalkyl
radicals, optionally containing hydrogen atoms, silicon or
germanium atoms, or a --O-Al(R.sup.18).sub.2 group and, if
appropriate, some substituents R.sup.8 can be halogen atoms.
[0075] In particular, alumoxanes of the formula: 3
[0076] can be used in the case of linear compounds, wherein n is 0
or an integer of from 1 to 40 and the substituents R.sup.18 are
defined as above, or alumoxanes of the formula: 4
[0077] can be used in the case of cyclic compounds, wherein n is an
integer of from 2 to 40 and the R.sup.18 substituents are defined
as above.
[0078] The substituents R.sup.18 are preferably ethyl, isobutyl or
2,4,4-trimethyl-pentyl groups.
[0079] Examples of alumoxanes suitable for use according to the
present invention are methylalumoxane (MAO), isobutylalumoxane
(TIBAO), 2,4,4-trimethyl-pentylalumoxane (TIOAO) and
2,3-dimethylbutylalumoxane.
[0080] The molar ratio between the aluminium and the metal of the
metallocene compound is in general comprised between 10:1 and
20000:1, and preferably between 100:1 and 5000:1.
[0081] Non-limiting examples of compounds able to form an
alkylmetallocene cation are compounds of the formula
Y.sup.+Z.sup.-, wherein Y.sup.+ is a Brnsted acid, able to donate a
proton and to react irreversibly with a substituent X of the
compound of the formula (I), and Z.sup.- is a compatible anion
which does not coordinate and which is able to stabilize the active
catalytic species which results from the reaction of the two
compounds and which is sufficiently labile to be displaceable by an
olefin substrate. Preferably, the anion Z.sup.- consists of one or
more boron atoms. More preferably, the anion Z.sup.- is an anion of
the formula BAr.sub.4.sup.(-), wherein the substituents Ar which
can be identical or different are aryl radicals such as phenyl,
penta-fluorophenyl or bis(trifluoromethyl)phenyl.
Tetrakis-pentafluorophe- nyl borate is particularly preferred.
Moreover, compounds of the formula BAr.sub.3 can conveniently be
used. Compounds of this type are described, for example, in the
published International patent application WO 92/00333, the content
of which is incorporated in the present description.
[0082] The catalysts of the present invention can also be used on
supports. This is achieved by depositing the metallocene compound
(A) or the product of the reaction thereof with the component (B),
or the component (B) and then the metallocene compound (A) on
supports such as, for example, silica, alumina, magnesium halides,
styrene/divinylbenzene copolymers, polyethylene or
polypropylene.
[0083] A suitable class of supports which can be used is that
constituted by porous organic supports functionalized with groups
having active hydrogen atoms. Particularly suitable are those in
which the organic support is a partially cross-linked styrene
polymer. Supports of this type are described in European
application EP-633 272.
[0084] Another class of inert supports particularly suitable for
use according to the invention is that of the olefin, particularly
propylene, porous prepolymers described in International
application WO 95/26369.
[0085] A further suitable class of inert supports for use according
to the invention is that of the porous magnesium halides such as
those described in International application WO 95/32995. The solid
compound thus obtained, in combination with the further addition of
the alkylaluminium compound either as such or prereacted with water
if necessary, can be usefully employed in the gas-phase
polymerization.
[0086] By polymerizing ethylene with alpha-olefins in the presence
of the above particular metallocenes it is possible to obtain in
high yields, at temperature of industrial interest (i.e. higher
than 50.degree. C.), ethylene copolymers having an extremely
homogeneous distribution of thecomonomers in the polymeric chain,
i.e. the number of sequences of two or more consecutive units of
the alpha-olefin derived units is very low. The analysis of the
distribution of the alpha-olefins in the copolymers of the
invention has been carried out using .sup.13C-NMR spectroscopy. The
assignments, in the case of ethylene/1-hexene copolymers, were
carried out as described by J. C.Randall in "Macromol. Chem. Phys.
(1989), 29, 201.
[0087] The process for the polymerization of olefins according to
the invention can be carried out in the liquid phase in the
presence or absence of an inert hydrocarbon solvent, or in the gas
phase. The hydrocarbon solvent can either be aromatic such as
toluene, or aliphatic such as propane, hexane, heptane, isobutane
or cyclohexane.
[0088] The polymerization temperature is generally comprised
between -100.degree. C. and +100.degree. C. and, particularly
between 10.degree. C. and +90.degree. C. The polymerization
pressure is generally comprised between 0.5 and 100 bar.
[0089] The lower the polymerization temperature, the higher are the
resulting molecular weights of the polymers obtained.
[0090] The polymerization yields depend on the purity of the
metallocene compound of the catalyst.
[0091] The metallocene compounds obtained by the process of the
invention can therefore be used as such or can be subjected to
purification treatments.
[0092] The components of the catalyst can be brought into contact
each other before the polymerization. The pre-contact
concentrations are generally between 1 and 10.sup.-8 mol/l for the
metallocene component (A), while they are generally between 10 and
10.sup.-8mol/l for the component (B). The pre-contact is generally
effected in the presence of a hydrocarbon solvent and, if
appropriate, of small quantities of monomer. In the pre-contact it
is also possible to use a non-polymerizable olefin such as
isobutene, 2-butene and the like.
[0093] In the copolymers obtainable with the process of the
invention, the content by mole of ethylene derived units is
generally higher than 50%, and preferably it is comprised between
80% and 99%.
[0094] The molar content of alpha-olefin derived units is
preferably comprised between 0% and 50% and, more preferably,
between 1% and 20%.
[0095] The content of polyene derived units is preferably comprised
between 0% and 4% and, more preferably between 0% and 3%.
[0096] Non-limiting examples of alpha-olefins which can be used as
comonomers in the process of the invention are propylene, 1-butene,
1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene,
4,6-dimethyl-1-heptene, 1-decene, 1-dodecene, 1-tetradecene,
1-hexadecene, 1-octadecene, 1 -eicosene and allylcyclohexane.
[0097] Non-limiting examples of cycloolefins olefins which can be
used as comonomers in the process of the invention are
cyclopentene, cyclohexene and norbomene.
[0098] The copolymers according to the invention can also contain
units derived from polyenes.
[0099] The polyenes which can be used as comonomers in the
copolymers according to the present invention are comprised in the
following classes:
[0100] non-conjugated diolefins able to cyclopolymerize such as,
for example, 1,5-hexadiene, 1-6-heptadiene,
2-methyl-1,5-hexadiene;
[0101] dienes capable of giving unsaturated monomeric units, in
particular conjugated dienes such as, for example, butadiene and
isoprene, and linear non-conjugated dienes, such as, for example,
trans 1,4-hexadiene, cis 1,4-hexadiene, 6-methyl-1,5-heptadiene,
3,7-dimethyl- 1,6-octadiene, 11-methyl-1,10-dodecadiene.
[0102] In the case of polyenes other than non-conjugated
alpha-omega-diolefins having 6 or more carbon atoms, these are
preferably used in quantities of between 0 and 3 mol % as a second
alpha-olefin comonomer.
[0103] A particular interesting embodiment of the present invention
is constituted of copolymers of ethylene with 1-hexene or higher
alpha-olefins.
[0104] The copolymers according to the present invention are
characterized by an extremely homogeneous distribution of the
comonomers in the polymeric chain and, more precisely, by the fact
of containing an extremely low number of sequences of two ore more
consecutive alpha-olefin units.
[0105] The analysis of the distribution of the comonomer units in
the copolymers of the invention has been carried out by means of
.sup.13C-NMR spectroscopy. The assignments were carried out as
described by Randall in Macromol.Chem.Phys. 1989, 29, 201. The
distribution of triads, in the case of ethylene/1-hexene, are
calculated by the following relationship:
[0106] HHH=T.sub..beta..beta. EHE=T.sub..delta..delta.
HHE=T.sub..beta..delta. HEH=S.sub..beta..beta.
HEE=S.sub..beta..delta.
EEE=0.5(S.sub..delta..delta.+0.5S.sub..gamma..delta.)
[0107] wherein EHE, HHE and HHH represent the sequence
ethylene/1-hexene/ethylene, 1-hexene/1-hexene/ethylene and
1-hexene/1-hexene/1-hexene respectively in the copolymer. For the
NMR nomenclature, see J. Carmen, R. A. Harrington, C. E. Wilkes,
Macromolecules, 10, 537 (1977). The values are normalized. The
higher the number of isolated 1-hexene units in the polymeric
chain, the more the values of the ratio EHE/(EHE+HHE+HHH) become
closer to the unit.
[0108] The number of 1-hexene sequences seems to be a function of
the amount of 1-hexene units present in the chain.
[0109] The tables 2 and 3 refer to ethylene/1-hexene copolymers
obtained with a process according to the present invention.
[0110] In particular, in table 2 there are reported the ratios
EHE/(EHE+HHE+HHH) as a function of the molar percentage of 1-hexene
in the chain for ethylene/1-hexene copolymers obtained with a
process according to the present invention, in the presence of the
above reported metallocene compounds. The amounts of 1-hexene units
being equal, the values of the ratio EHE/(EHE+HHE+HHH) for the
copolymers of the invention are always higher than those for the
copolymers obtained with metallocenes used in the comparative
examples, reflecting the improved distribution of 1-hexene units in
the chain.
[0111] In the copolymers according to the present invention, the
product of the reactivity ratios r.sub.1.r.sub.2, wherein r.sub.1
is the relative reactivity of the comonomer versus ethylene and
r.sub.2 that of ethylene versus the comonomer, appears to be
extremely low. In particular, it is generally lower than 0.30,
preferably lower than 0.20, more preferably lower than 0.15. The
diads were calculated from the triads distribution.
[0112] In the case of ethylene/1-hexene, the product of the
reactivity ratios r.sub.1.r.sub.2 are calculated according to the
following formulae as described in J. Uozomi, K. Soga, Mak. Chemie,
193, 823,(1992):
[0113] r.sub.1=2EE/(EH)X
[0114] r.sub.1.r.sub.2=4(EEHH)/EH.sup.2, wherein
[0115] X=[E]/[H] monomer molar ratio in the polymerization
bath.
[0116] In particular, the ratio EHE/(EHE+HHE+HHH) satisfies the
following relationship:
EHE/(EHE+HHE+HHH).gtoreq.0.75
[0117] preferably:
EHE/(EHE+HHE+HHH).gtoreq.0.85
[0118] more preferably
EHE/(EHE+HHE+HHH).gtoreq.0.9.
[0119] The copolymers of the present invention have intrinsic
viscosity values (I.V.) generally higher than 0.5 dl/g and
preferably higher than 1.0 dl/g. The intrinsic viscosity can reach
values of 3.0 dl/g and even higher.
[0120] The molecular weight of the polymers can be also varied by
varying the type or the concentration of the catalyst components or
using molecular weight regulators such as, for example,
hydrogen.
[0121] Generally, the copolymers of the present invention are
endowed with a narrow molecular weight distribution. The molecular
weight distribution is represented by the ratio M.sub.w/M.sub.n
which, for the copolymers of the present invention, when the
metallocene used is a pure isomer, is generally lower than 4,
preferably lower than 3.5 and, more preferably, lower than 3.
[0122] The molecular weight distribution can be varied by using
mixtures of different metallocene compounds or by carrying out the
polymerization in several stages at different polymerization
temperatures and/or different concentrations of the molecular
weight regulators.
[0123] The copolymers of the invention are transformable into
shaped articles by conventional thermoplastic material processing
(molding, extrusion, injection etc.).
[0124] The following examples are given for illustrative purposes
and are not intended to limit the scope of the invention.
GENERAL PROCEDURES AND CHARACTERIZATIONS
[0125] The following abbreviations are used:
[0126] THF=tetrahydrofuran
[0127] Et.sub.2O=ethyl ether
[0128] NaOEt=sodium ethoxide
[0129] .sup.tBuOK=potassium tert-butoxide
[0130] DMSO=dimethyl sulfoxide
[0131] DMF=N,N-dimethylformamide
[0132] BuLi=butyllithium
[0133] All operations were performed under nitrogen by using
conventional Schlenk-line techniques. Solvents were distilled from
blue Na-benzophenone ketyl (Et.sub.2O), CaH.sub.2
(CH.sub.2Cl.sub.2), or AliBu.sub.3 (hydrocarbons), and stored under
nitrogen. BuLi (Aldrich) was used as received.
[0134] The .sup.1H-NMR analyses of the metallocenes were carried
out on an DPX 200 Bruker spectrometer (CD.sub.2Cl.sub.2, referenced
against the middle peak of the triplet of residual CHDCl.sub.2 at
5.35 ppm). All NMR solvents were dried over P.sub.2O.sub.5 and
distilled before use. Preparation of the samples was carried out
under nitrogen using standard inert atmosphere techniques.
[0135] The .sup.13C-NMR and .sup.1H-NMR analyses of the polymers
were carried out on a Bruker DPX 400 spectrometer operating at
400.13 MHz and 100.61 MHz respectively. The samples were analyzed
as solutions in tetrachlorodideuteroethane at 120.degree. C.
[0136] The intrinsic viscosity (I.V.) was measured in tetralin at
135.degree. C.
[0137] The melting points of the polymers (Tm) were measured by
Differential Scanning Calorimetry (D.S.C.) on an instrument DSC
Mettler, according to the following method. About 10 mg of sample
obtained from the polymerization were cooled to -2520 C. and
thereafter heated at 200.degree. C. with a scanning speed
corresponding to 20.degree. C. minute. The sample was kept at
200.degree. C. for 5 minutes and thereafter cooled to 0.degree. C.
with a scanning speed corresponding to 20.degree. C./minute. Then,
a second scanning was carried out with a scanning speed
corresponding to 10.degree. C./min. The values reported are those
obtained in the second scanning.
[0138] The distribution of molecular weights was determined by GPC
carried out on an instrument WATERS 150 in orthodichlorobenzene at
135.degree. C.
PREPARATION OF THE METALLOCENES
[0139] The synthesis of
rac-isopropylidene-bis(3-isopropyl-indenyl)zirconi- um dichloride
(rac-CMe.sub.2(3-iPr-Ind)ZrCl.sub.2),
rac-isopropylidene-bis(3-trimethylsilyl-indenyl)zirconium
dichloride (rac-CMe.sub.2(3-Me.sub.3Si-Ind).sub.2ZrCl.sub.2),
rac-isopropylidene-bis(3-methyl-indenyl)zirconium dichloride
(rac-CMe.sub.2(3-Me-Ind).sub.2ZrCl.sub.2),
rac-isopropylidene-bis(3-ter-b- utyl-indenyl)zirconium dichloride
(rac-CMe.sub.2(3-tBu-Ind).sub.2ZrCl.sub.- 2) was carried out as
described in WO 96/22995.
[0140] Synthesis of rac-Methylene-bis(3-t-butyl-1-indenyl)zirconium
dichloride
[0141] (a) Synthesis of t-butyl-indene
[0142] 42.0 g of indene (technical grade, 94% by GC, 39.5 g, 340
mmol), 50% w aqueous KOH (308 g in 308 mL) and 15.8 g of Adogen
(Aldrich, 34 mmol) dissolved in 139.7 g of tert-butylbromide
(1019.6 mmol) were introduced in this order, at room temperature,
in a 1 L, jacketed glass reactor with mechanical stirrer (Buchi).
The organic phase turns green. The mixture is heated to 60.degree.
C. and vigorously stirred for two hours (a pressure build-up to 2.5
bar-g is observed) and then cooled to room temperature. Total
reaction time is 3 h. The organic phase is extracted with technical
hexane (3.times.200 mL) and analyzed by GC. Conversion: 74.5% w of
3-tert-butyl-indene and 1.8% of 1-tert-butyl-indene, unreacted
indene 13.7% w. The solution was evaporated under reduced pressure
(rotovac) and the resulting dark brown viscous liquid was distilled
at 1 mmHg, collecting the fraction boiling between 70 and
80.degree. C. (40 g, 76.8% of 3-tert-butyl-indene and 19.5% of
1-tert-butyl-indene, no indene).
[0143] (b) Synthesis of bis(3-t-butyl-indenyl)methane
[0144] In a three neck, 1 L flask with stirring bar were introduced
in this order: 10.32 g of .sup.tBuOK (92 mmol), 400 mL of DMF, 80.6
g of tert-butyl-indene (98.2% by GC, 460 mmol), and then 18.6 mL of
aqueous formalin (37%, 6.9 g, 230 mmol) were added dropwise over 15
min. A mildly exothermic reaction is observed and the solution
turns red. The mixture was stirred at room temperature for 2 hours,
then the reaction was quenched by pouring the mixture on ice and
NH.sub.4Cl, extracted with Et.sub.2O (2.times.250 mL), concentrated
under reduced pressure to yield an orange oily product with the
following G.C. composition: 1-.sup.tBuInd, 0.3%; 3-.sup.tBuInd,
2.8%; target product, 78.3%; the rest being byproducts. Yield of
raw product: 83.6 g, corresponding to a yield of 79.9%. The orange
oily product crystallized upon standing (ca. 1 h). This product was
further purified by washing with pentane, which leaves
bis(1-tert-butyl-3-indenyl)methane as a light yellow powder, 99.8%
pure by G.C.
[0145] (c) Synthesis of methylene-bis(3-t-butyl-1-indenyl)zirconium
dichloride
[0146] 11.0 g of pure bis(1-tert-butyl-3-indenyl)methane (30.9
mmol) were dissolved in 200 mL Et.sub.2O in a 250 mL Schlenk tube,
and the solution cooled to -15.degree. C. 40 mL of 1.6 M BuLi in
hexane (63.3 mmol) were added dropwise over 15 min with stirring.
The solution is allowed to warrn to room temperature and stirred
for 4.5 hours. An increasing turbidity develops with final
formation of a yellow suspension. 7.2 g of ZrCl.sub.4 (30.9 mmol)
were slurried in 200 mL pentane. The two mixtures were both cooled
to -80.degree. C. and the Li salt solution in Et.sub.2O were
quickly added to the ZrCl.sub.4 slurry in pentane. The cooling bath
is removed. After 20 min the color of the slurry changes from
yellow to red. The reaction mixture is stirred overnight at room
temperature, and then brought to dryness under reduced pressure.
The red powder was slurried in 200 mL of pentane and transferred
into a filtration apparatus equipped with side arm (to allow
solvent refluxing) connecting the system above and below the frit,
a receiving flask on the bottom and bubble condenser on the top.
The red solid was extracted with refluxing pentane for about 3.5
hours. The filtrate was evaporated to dryness under reduced
pressure to give a red paste which contained
rac-CH.sub.2(3-.sup.tBu-Ind)- .sub.2ZrCl.sub.2 free from its meso
isomer, but containing polymeric byproducts. The paste was washed
twice with Et.sub.2O (20+10 mL) to give 1 g of pure product. The
red solid on the frit was further extracted with CH.sub.2Cl.sub.2
until the filtrate was light orange (6 hours) and dried.
.sup.1H-NMR shows the presence of pure
rac-CH.sub.2(3-tBu-lnd).sub.2ZrCl.- sub.2 (7.25 g). Total yield
(8.25 g of red powder) of
rac-CH.sub.2(3-.sup.tBu-Ind).sub.2ZrCl.sub.2 is 52%. .sup.1H NMR
(CDCl.sub.3, d, ppm): s, 1.41, .sup.tBu, 18H; s, 4.78, CH.sub.2,
2H; s, 5.79, 2H, Cp-H; m, 7.15, 2H, m, 7.36, 2H; m, 7.47, 2H; m,
7.78, 2H.
[0147] Synthesis of
methylene-bis(3-iso-propyl-1-indenyl)ZrCl.sub.2
[0148] (a) Synthesis of 3-iso-propyl-1-indene
[0149] 25 g of indene (Aldrich, 94.4%) in 140 mL Et.sub.2O were
placed in a 0.5 L flask and cooled to -20.degree. C.; 141 mL of
n-BuLi (1.6 M in hexane, 226 mmol) were added dropwise in about
30'. The reaction mixture was allowed to warm to room temperature
and then stirred for 5 hours (brown-orange solution). This solution
was then slowly added to a solution of 101 mL of i-PrBr (Aldrich,
MW 123 g/mol, d=1.31 g/mL, 1.07 mol) in 140 mL Et.sub.2O maintained
at 0.degree. C. The reaction was allowed to proceed with stirring
at room temperature for 72 hours. Aliquots were taken for GC
analysis after 24 h (Indene=12.1%, i-PrInd=56.5%,
(i-Pr).sub.2Ind=18.8%), 48 h (Indene=4.6%, i-PrInd=66.8%,
(i-Pr).sub.2Ind=16.5%), and final (Indene=4.8%, i-PrInd=65.3%,
(i-Pr).sub.2Ind=16.8%). The mixture was poured onto 300 g of ice,
the water layer was extracted with Et.sub.2O (3.times.200 mL) and
the Et.sub.2O wash combined with the organic layer, dried over
MgSO.sub.4 and after filtration the solvent was removed under
vacuum to leave 30.9 g of a yellow oil (yield based on GC analysis
is 62%). 18 g of this oil was distilled (adding NaOH pellets to
avoid polymerization, with a 20 cm vigreux column) collecting the
fraction boiling at 95-105.degree. C. at 10 mmHg, 10 g, GC: i-PrInd
(2 isomers)=92.1%, (i-Pr).sub.2Ind=6.7%. .sup.1H NMR (CDCl.sub.3,
d, ppm): d, 1.45, 1.47, 6H; m, 3.47, CH, 1H; s, 3.47, 2H, CH.sub.2;
s, 6.35, 1H,; m, 7.47, 2H; m, 7.3-7.7, 4H. Major isomer is
3-i-Pr-indene.
[0150] (b) Synthesis of bis(3-iso-propyl-indenyl)methane
[0151] In a three neck, 500 mL flask with stirring bar were
introduced in this order: 10 g of i-Pr-indene (92%, MW 158, 58.3
mmol) dissolved in 250 mL of DMSO, and 1.42 g of t-BuOK (MW 112.82.
12.6 mmol). The yellow solution turns green. 2.56 mL of aqueous
formalin (37%, MW 30.03, 31.6 mmol) in 70 mL of DMSO were added in
15'. A mildly exothermic reaction is observed and the solution
turns dark brown. At the end of the addition the reaction mixture
was stirred for 16 h at room temperature. The reaction was quenched
by pouring the mixture on 200 g ice with 0.3 g NH.sub.4Cl. The
organic product was extracted with Et.sub.2O, the water layer was
washed with Et.sub.2O (3.times.100 mL), the organic layers
combined, dried over MgSO.sub.4, filtered and concentrated to leave
13.65 g of yellow oil, which contains 32% of the desired product by
GC analysis.
[0152] (c) Synthesis of
methylene-bis(3-iso-propyl-indenyl)ZrCl.sub.2
[0153] 13.6 g of raw bis(3-iso-propyl-1-indenyl)methane were
dissolved in 200 mL Et.sub.2O in a 250 mL Schlenk tube, and the
solution cooled to -80.degree. C. 33.3 mL of 2.5 M BuLi in hexane
(83.2 mmol) were added dropwise over 15 min with stirring. The
solution is allowed to warm to room temperature and stirred for 5
hours. An increasing turbidity develops with final formation of an
orange precipitate. Et.sub.2O was removed under vacuum and 200 mL
of toluene were added. 9.7 g of ZrCl.sub.4 (MW 233.03, 41.62 mmol)
were slurried in 200 mL of toluene. The two mixtures were both
cooled to -80.degree. C. and the ZrCl.sub.4 slurry in toluene was
quickly added to the Li salt solution in toluene. The cooling bath
is removed. The reaction mixture is stirred overnight at room
temperature. Filtration: the residue was a sticky glue
(eliminated). The filtrate was evaporated to 25 mL under reduced
pressure: the solid precipitated was isolated by filtration:
.sup.1H NMR (CD.sub.2Cl.sub.2, d, ppm): 92% meso: ps-t, 1.31, i-Pr,
12H; quintet, 3.32, CH, 2H; quartet, 4.84, 4.91, 5.01, 5.08, 2H,
CH.sub.2-bridge; s, 5.81, 2H, Cp-H; t, 6.9-7.0, 2H; t, 7.06-7.15,
2H; m, 7.47-755, 4H. See FIG. 2.
[0154] The filtrate was dried to give a red sticky solid (5.8 g),
which was dispersed in 30 mL Et.sub.2O and 2 mL CH.sub.2Cl.sub.2,
and filtered at 0.degree. C. The residue was dried to give 1 g of
red powder. .sup.1H-NMR shows the presence of chemically pure
CH.sub.2(3-i-Pr-Ind).su- b.2ZrCl.sub.2 (80% racemo, 20% meso).
.sup.1H NMR (CD.sub.2Cl.sub.2, d, ppm): d, 1.17, 1.21,CH3, 6H; d,
1.31,1.34, CH3, 6H; quintet, 3.13-3.20, CH, 2H; s, 4.82, 2H
CH2-bridge; s, 5.78, 2H, Cp-H; t, 7.07-7.13, 2H; t, 7.25-7.30, 2H;
d, 7.47-7.52, 2H; d, 7.60-7.65, 2H.
[0155] Synthesis of
methylene-bis(3-trimethylsilyl-1-indenyl)zirconium dichloride
[0156] (a) Synthesis of bis(1-trimethylsilyl-3-indenyl)methane
[0157] 9.56 g of bis(1-indenyl)methane (39,1 mmol), obtained as
reported in Synthesis 10, were dissolved in 70 ml Et.sub.2O in a
250 ml Schlenk tube, and the solution cooled to -78.degree. C. 33.0
ml of 2.5 M BuLi in hexane (82.5 mmol) were added dropwise, over 30
minutes under stirring. The obtained solution was allowed to warm
to room temperature and then stirred for 3 hours, thus obtaining a
brown dark, lightly cloudy solution. 10.5 ml of
chlorotrimethylsilane (82.7 mmol) were dissolved in 50 ml
Et.sub.2O. The two mixtures were both cooled to -78.degree. C. and
the Li salt solution in Et.sub.2O was added, over 20 minutes, to
the chlorotrimethylsilane solution in Et.sub.2O; the color of the
solution turned from brown to maroon. The cooling bath was removed
and the reaction mixture was stirred overnight at room temperature.
After 20 hours, the solution, lightly clearer, was quenched with a
few ml of MeOH, filtered and concentrated, thus giving 11.28 g of
bis(1-trimethylsilyl-3-- indenyl)methane as a brown dark oil (74.2%
yield, meso/rac=1/1).
[0158] .sup.1H NMR (CDCl.sub.3, .delta., ppm): -0.04 to -0.03 (s,
18H, CH.sub.3); 3.35-3.45 (m, 2H, CH or CH.sub.2 bridge); 3.93-4.00
(bs, 2H, CH.sub.2 bridge or CH); 6.30-6.40 (m, 2H, Cp-H); 7.10-7.50
(m, 8H).
[0159] (b) Synthesis of
methylene-bis(3-trimethylsilyl-1-indenyl)zirconium dichloride
CH.sub.2(3-Me.sub.3Si-Ind).sub.2ZrCl.sub.2
[0160] 4.90 g of bis(1-trimethylsilyl-3-indenyl)methane (12.6
mmol), obtained as reported above, were dissolved in 70 ml
Et.sub.2O in a 250 ml Schlenk tube, and the solution was cooled to
-70.degree. C. 10.6 ml of 2.5 M BuLi in hexane (26.5 mmol) were
added dropwise under stirring. The solution was allowed to warm to
room temperature and stirred for 3 hours. An increasing turbidity
developed with the final formation of a brown dark suspension. 2.94
g of ZrCl.sub.4 (12.6 mmol) were slurried in 50 ml of pentane. The
two mixtures were both cooled to -70.degree. C. and the Li salt
solution in Et.sub.2O was quickly added to the ZrCl.sub.4 slurry in
pentane; then the cooling bath was removed. The reaction mixture
was maintained under stirring overnight at room temperature and the
color of the suspension turned to maroon. After filtration, the
residue was concentrated and then extracted with toluene to give a
pink-red powder. The .sup.1H-NMR analysis showed the presence of
meso/rac CH.sub.2(3-Me.sub.3Si-1-Ind).sub.2ZrCl.sub.2=75/25. The
filtrate was dried to give a brown dark sticky solid and pentane
was added; the obtained mixture was stirred at room temperature for
1 hour and then filtered. The residue was finally dried to give
1.87 g of an orange powder. The .sup.1H-NMR analysis showed the
presence of rac/meso
CH.sub.2(3-Me.sub.3Si-1-Ind).sub.2ZrCl.sub.2=81/19 (27.0%
yield).
[0161] .sup.1H NMR (CD.sub.2Cl.sub.2, .delta., ppm): 0.22 (s, 6H,
CH.sub.3); 0.34 (s, 6H, CH.sub.3); 4.79 (s, CH.sub.2 bridge, 2H);
4.93 (q, CH.sub.2 bridge, 2H); 6.47 (s, Cp-H, 2H); 6.57 (s, Cp-H,
2H); 7.06-7.72 (m, 16H).
POLYMERIZATION
[0162] Methylalumoxane (MAO)
[0163] A commercial (Witco) 10 % toluene solution was dried in
vacuum until a solid, glassy material was obtained which was finely
crushed and further treated in vacuum until all volatiles were
removed (4-6 hours, 0.1 mmHg, 50.degree. C.) to leave a white,
free-flowing powder.
[0164] Tris(2,4,4-trimethyl-pentyl)aluminum (TIOA)
[0165] A commercial (Witco) sample was used diluted to a 1 M
solution in the indicated solvent.
EXAMPLE 1
[0166] Ethylene/1-hexene copolymerization
[0167] A 200 ml glass autoclave, provided with magnetic stirrer,
temperature indicator and feeding line for the ethylene, was
purified and fluxed with ethylene at 35.degree. C. At room
temperature 90 ml of heptane and 10 ml of 1-hexene were introduced.
The catalytic system was separately prepared in 10 ml of heptane by
consecutively introducing 0.22 ml of 1 M toluene solution of MAO
and 0.1 mg (2.04.times.10.sup.-6 mol) of
methylene-bis(3-iso-propyl-1-indenyl)zirconium dichloride solved in
the lowest possible amount of toluene. After 5 minutes stirring,
the solution was introduced into the autoclave under ethylene flow,
the reactor was closed, the temperature was risen to 70.degree. C.
and the reactor was pressurized to 4.5 bar with ethylene. The total
pressure was kept constant by feeding ethylene. After 15 minutes
the polymerization was stopped by cooling, degassing the reactor
and by the introduction of 1 ml of methanol. The product was washed
with acidic methanol, than with methanol and finally dried in oven
at 60.degree. C. under vacuum. The yield was 3.59 g corresponding
to an activity of 769.3 Kg/gZr.h. The intrinsic viscosity of the
polymer was 1.22 dl/g.
[0168] The characterization data of the copolymer so obtained are
shown in Table 2.
EXAMPLE 2
[0169] Example 1 was repeated, but with the difference that instead
of 10 ml 1-hexene 5 ml 1-hexene were introduced.
[0170] The polymerization conditions are reported in Table 1.
[0171] The characterization data of the copolymer obtained are
shown in Table 2.
EXAMPLE 3
[0172] Example 1 was repeated, but with the difference that instead
of MAO, 0.27 mmols of TIOA/H.sub.2O (Al/H.sub.2O=2.11 as molar
ratio) were used. The yield was 0.73 g corresponding to an activity
of 123.2 Kg/gZr.h. The intrinsic viscosity of the polymer was 2.58
dL/g.
[0173] The polymerization conditions are reported in Table 1.
[0174] The characterization data of the copolymer obtained are
shown in Table 2.
EXAMPLE 4
[0175] Example 1 was repeated, except that 0.22 mmols of a 9:1
mixture of TIOA-O/MAO was used. TIOA-O was obtained at
Al/H.sub.2O=2.07 as molar ratio.
[0176] The polymerization conditions are reported in Table 1.
[0177] The characterization data of the copolymer obtained are
shown in Table 2.
EXAMPLE 5
[0178] Example 1 was repeated, but with the difference that 0.12 mg
Me.sub.2C(3-iPr-Ind).sub.2ZrCl.sub.2 and 0.24 mmols MAO were
used.
[0179] The polymerization conditions are reported in Table 1.
[0180] The characterization data of the copolymer obtained are
shown in Table 2.
EXAMPLE 6
[0181] Example 1 was repeated, except that 0.12 mg
CMe.sub.2(3-i-Pr-Ind).s- ub.2ZrCl.sub.2 and 0.24 mmols of a 9:1
mixture of TIOA-O/MAO was used. TIOA-O was obtained at
Al/H.sub.2O=2.07 as molar ratio.
[0182] The polymerization conditions are reported in Table 1.
[0183] The characterization data of the copolymer obtained are
shown in Table 2.
EXAMPLE 7
[0184] Example 1 was repeated, but with the difference that 0.2 mg
H.sub.2C(3-Me.sub.3Si-Ind).sub.2ZrCl.sub.2 was used.
[0185] The polymerization conditions are reported in Table 1.
[0186] The characterization data of the copolymer obtained are
shown in Table 2.
EXAMPLE 8
[0187] Example 1 was repeated, except that 0.1 mg
CMe.sub.2(3-Me-Ind).sub.- 2ZrCl.sub.2 was used, and that 0.23 mmols
TIOA/H.sub.2O (Al/H.sub.2O=2.07 as molar ratio) and no MAO was
used.
[0188] The polymerization conditions are reported in Table 1.
[0189] The characterization data of the copolymer obtained are
shown in Table 2.
EXAMPLE 9
[0190] Example 1 was repeated, but with the difference that 0.12 mg
Me.sub.2C(3-Me.sub.3Si-Ind).sub.2ZrCl.sub.2 was used.
[0191] The polymerization conditions are reported in Table 1.
[0192] The characterization data of the copolymer obtained are
shown in Table 2.
EXAMPLE 10
[0193] Ethylene/1-octene copolymerization
[0194] A 260 ml glass autoclave, provided with magnetic stirrer,
temperature indicator and feeding line for the ethylene, was
purified and fluxed with ethylene at 35.degree. C. At room
temperature were introduced 86 ml of heptane and 4.1 ml of 1-octene
distilled over LiAlH.sub.4. The catalytic system was prepared by
consecutively introducing MAO (0.21 mmol. as 1M toluene solution)
and 0.1 mg (0.000205 mg.at. Zr) of the metallocene of example 1
solved in toluene (the low amount as possible). After 5 minutes
stirring, the solution was diluted to 10 ml with heptane and was
introduced into the autoclave under ethylene flow, the reactor was
closed, the temperature risen to 70.degree. C. and pressurized to 4
bar. The total pressure was kept constant by feeding ethylene for
20 minutes. The polymerization was stopped by cooling, degassing
the reactor and the introduction of 1 ml of methanol. The achieved
polymer was washed with acidic methanol, than with methanol and
dried in oven at 60.degree. C. under vacuum. 1.68 g. of polymer was
obtained (270 Kg/gZr/h) with the following characteristics:
I.V.=1.82 dL/g; 1-octene=5.73 mol. %, Tm=92.5.degree. C.;
.DELTA.H=63 J/g;
[0195] Triad distribution in mol. %:[EXE]=5.73; [XXX]=0; [XXE]=0;
[EXE]/X.sub.tot=1. Where X has the meaning of 1-octene.
EXAMPLE 11
[0196] Ethylene/1-decene polymerization
[0197] A 200 ml glass autoclave, provided with magnetic stirrer,
temperature indicator and feeding line for the ethylene, was
purified and fluxed with ethylene at 35.degree. C. At room
temperature were introduced 85 ml of heptane and 5 ml of 1-decene
distilled over LiAlH.sub.4. The catalytic system was prepared by
consecutively introducing MAO (0.22 mmol. as 1M toluene solution)
and 0.1 mg (0.000205 mg.at. Zr) of the metallocene of example 1
solved in toluene (the low amount as possible). After 5 minutes
stirring, the solution was diluted to 10 ml with heptane and was
introduced into the autoclave under ethylene flow, the reactor was
closed, the temperature risen to 70.degree. C. and pressurized to 4
bar. The total pressure was kept constant by feeding ethylene for
10 minutes. The polymerization was stopped by cooling, degassing
the reactor and the introduction of 1 ml of methanol. The achieved
polymer was washed with acidic methanol, than with methanol and
dried in oven at 60.degree. C. under vacuum. 3.2 g. of polymer were
obtained (1045 Kg/gZr/h) with the following characteristics:
I.V.=2.01 dL/g; 1-decene=7.48 mol. %, Tm=72.8.degree. C.;
.DELTA.H=63 J/g; Triad distribution in mol. %:[EXE]=7.48; [XXX]=0;
[XXE]=0; [EXE]/X.sub.tot=1. X has the meaning of 1-decene.
EXAMPLE 12 (Comparison)
[0198] Example 1 was repeated except that
rac-CH.sub.2(3-tBu-Ind).sub.2ZrC- l.sub.2 was used.
[0199] The polymerization conditions are reported in Table 1.
[0200] The characterization data of the copolymer obtained are
shown in Table 2.
EXAMPLE 13 (Comparison)
[0201] Example 1 was repeated except that 0.3 mg
rac-CMe.sub.2(3-tBu-Ind).- sub.2ZrCl.sub.2 and 1.15 mmol
TIOA/H.sub.2O (Al/H.sub.2O=4.18 as molar ratio), and that 15 ml of
1-hexene were used.
[0202] The polymerization conditions are reported in Table 1.
[0203] The characterization data of the copolymer obtained are
shown in Table 2.
EXAMPLE 14 (Comparison)
[0204] Example 1 was repeated except that
rac-CMe.sub.2(Ind).sub.2ZrCl.sub- .2 was used.
[0205] The polymerization conditions are reported in Table 1.
[0206] The characterization data of the copolymer obtained are
shown in Table 2.
EXAMPLE 15 (Comparison)
[0207] Example 1 was repeated except that
rac-CH.sub.2(Ind).sub.2ZrCl.sub.- 2 was used.
[0208] The polymerization conditions are reported in Table 1.
[0209] The characterization data of the copolymer obtained are
shown in Table 2.
1TABLE 1 Example zirconocene dichloride AI/Zr 1-hexene (ml) Time
(min) yield (g) Activity (Kg/g.sub.Zr/h) 1
CH.sub.2(3-iPr-Ind).sub.2 0.1 1000 10 15 3.59 769.3 2 " 0.1 1000 5
10 4.12 1324.4 3 " 0.1 1000 5 15 0.73 123.2 4 " 0.1 1000 5 10 1.43
460 5 CMe.sub.2(3-iPr-Ind).sub.2 0.1 1000 5 10 3.01 852.6 6 " 0.1
1000 10 15 0.67 126.5 7 CH.sub.2(3-Me.sub.3Si-Ind).sub.2 0.2 1000
10 15 1.96 236 8 CMe.sub.2(3-Me-Ind).sub.2 0.1 1000 10 10 6 1818.0
9 CMe.sub.2(3-Me.sub.3Si-Ind).sub.2 0.1 1000 10 10 1.38 436.4 12
(comp.) CH.sub.2(3-tBu-Ind).sub.2 0.1 1000 10 10 1 339.9 13 (comp.)
CMe.sub.2(3-tBu-Ind).sub.2 0.3 2000 15 20 0.67 40.0 14 (comp.)
CMe.sub.2(Ind).sub.2 0.1 1000 10 15 2.28 297.6 15 (comp.)
CH.sub.2(Ind).sub.2 0.1 1000 10 15 1.68 295.0
[0210]
2 TABLE 2 N.M.R. Zirconocene 1-hexene EHE HHH HHE EHE/ I.V. Tm
.DELTA.H Ex. dichloride (% mols) (% mols) (EHE + HHE + HHH r.sub.1
r.sub.1 .multidot. r.sub.2 (dl/g) (.degree. C.) (J/g) 1
CH.sub.2(3-iPr-Ind).sub.2 17.86 16.8 0 1.06 0.94 6.41 0.113 1.22
n.d. # n.d. # 2 " 12.35 11.98 0 0.37 0.97 5.2 0.091 1.61 57.5 29 3
" 6.91 6.91 0 0 1 10.0 n.d. 2.58 74.8 58 4 " 7.27 7.27 0 0 1 9.83
n.d. 2.49 76.0 65.9 5 CMe.sub.2(3-iPr-Ind).sub.2 9 9 0 0 1 7.36
n.d. 2.1 73 52 6 " 11.24 10.8 0 0.44 0.96 12.26 0.142 2.8 63.4 43.1
7 CH.sub.2(3-Me.sub.3Si-Ind).sub.2 10.09 8.73 0 1.36 0.87 14.9
0.627 0.81 77.5 53.2 8 CMe.sub.2(3-Me-Ind).sub.2 18.41 17.6 0.22
0.59 0.96 6.25 0.105 0.5 44.7 5 9 CMe.sub.2(3-Me.sub.3Si-Ind).sub.2
8.78 7.8 0 0.98 0.89 16.1 0.52 1.29 76 51 12 (comp)
CH.sub.2(3-tBu-Ind).sub- .2 5.01 3.66 0 1.35 0.73 35.6 3.160 2.59
98.6 99.9 13 (comp) CMe.sub.2(3-tBu-Ind).sub.2 8.16 5.92 0.21 2.03
0.73 32.4 2.193 1.36 88.3 79.4 14 (comp)
CMe.sub.2(Ind).sub.2ZrCl.sub.2 24.0 18.7 1.66 4.18 0.76 5.04 0.559
0.18 oil 15 (comp) CH.sub.2(Ind).sub.2ZrCl.sub.2 26.56 20.06 1.32
5.17 0.76 3.71 0.362 0.14 oil # 1.sup.st run Tm = 48.degree.,
.DELTA.H = 3.8 J/g; n.d. = not determinable, due to the absence of
HH sequences
* * * * *