[TECHNICAL FIELD]
The present invention relates to an elastic terpolymer which is a copolymer of
ethylene, an alpha-olefin, and a diene, and a preparation method thereof. More
particularly, the present invention relates to a long-chain branched elastic terpolymer
10 capable of satisfying excellent mechanical properties and elasticity (flexibility) at the
same time, and a preparation method thereof.
[BACKGROUND OF ART]
EPDM rubber, which is an elastic terpolymer of ethylene, an alpha-olefin such
15 as propylene, etc., and a diene such as ethylidene norbornene, etc., has a molecular
structure having no unsaturated bond in the main chain, and has superior weather
resistance, chemical resistance, and heat resistance to the general conjugated diene
rubbers. Owing to these properties, the elastic terpolymers such as EPDM rubber
have been used in a wide variety of industrial applications such as automotive part
20 materials, electric wire materials, construction and hoses, gaskets, belts, bumpers,
blends with plastics, etc.
Conventionally, the elastic terpolymers such as EPDM rubber have been
mainly prepared by copolymerization of three kinds of monomers using a catalyst
containing a vanadium compound, for example, a vanadium-based Ziegler-Natta
catalyst. However, a large amount of the vanadium-based catalyst is needed because
of its low catalytic activity, thereby causing a problem of increasing the content of the
metal remaining in the copolymer. Thus, processes for catalyst removal and
5 decolorization are required after preparation of the copolymer, and the residual catalyst
in the polymer may cause deterioration of heat resistance, generation of impurities,
inhibition of vulcanization, etc. Practically, when the elastic terpolymer is prepared
using the catalyst containing the vanadium compound, it is difficult to control the
reaction temperature due to the low polymerization activity and low temperature
10 polymerization conditions, and also to control the molecular structure of the copolymer
due to difficulties in the control of feeding amounts of comonomers such as propylene
and a diene. Accordingly, there has been a limitation in the preparation of the elastic
terpolymer having various physical properties by using the vanadium-based catalyst.
Due to these problems, a method for preparing the elastic terpolymers such as EPDM
15 rubber using a Group IV metallocene-based transition metal catalyst instead of
vanadium-based Ziegler-Natta catalyst has been recently developed.
Since the Group IV transition metal catalyst exhibits high polymerization
activity in the olefin polymerization, it is possible to prepare copolymers having a
higher molecular weight, and also to easily control the molecular weight distribution
20 and composition of the copolymer. In addition, the catalyst has an advantage that a
variety of comonomers can be copolymerized. For example, US Patent Nos.
5,229,478 and 6,545,088, and Korean Patent No. 0488833 disclose that elastic
terpolymers having a high molecular weight can be obtained with excellent
2
polymerization activity by using various metallocene-based Group IV transition metal
catalysts obtained from ligands such as cyclopentadienyl, indenyl, fluorenyl, etc.
However, when three kinds of monomers are copolymerized using these
conventional Group IV transition metal catalysts, there is a disadvantage that
5 distributions of the repeating units derived from the monomers are not uniform in the
copolymer chains due to high reactivity for comonomers of alpha-olefins. As a result,
it is difficult to obtain elastic terpolymers such as EPDM rubber having excellent
elasticity and flexibility.
Further, US Patent No. 5,902,867 discloses a method for decreasing viscosity
10 of the polymer by broadening of the molecular weight distribution in order to improve
kneading processability and extrusion processability of EPDM. In this case, however,
there is a limitation that polymer separation occurs during processing due to low
molecular weight components included in the crosslinked rubber product, leading to
deterioration of surface properties and low-temperature properties.
15 Accordingly, there is a continuous demand for a long-chain branched elastic
terpolymer capable of satisfying excellent processability and elasticity (flexibility) at
the same time, and a preparation method capable of preparing the same with high
productivity and yield.
20 [PRIOR ART DOCUMENT[
[Patent Documents]
(Patent Document 0001) US Patent No. 5,229,478
(Patent Document 0002) US Patent No. 6,545,088
3
(Patent Document 0003) Korean Patent No. 0488833
(Patent Document 0004) US Patent No. 5,902,867
[DETAILED DESCRIPTION OF THE INVENTION]
5 [Technical Problem]
Accordingly, the present invention provides a long-chain branched elastic
terpolymer capable of satisfying excellent processability and elasticity (flexibility) at
the same time.
Further, the present invention provides a preparation method of an elastic
10 terpolymer, which is able to prepare the long-chain branched elastic terpolymer with
high productivity.
[Technical Solution!
The present invention provides an elastic terpolymer, in which the elastic
15 terpolymer is a copolymer of ethylene, an alpha-olefin having 3 to 20 carbon atoms,
and a diene, obtained in the presence of a Group IV transition metal catalyst, and
i) its weight average molecular weight measured by GPC is 100,000 to 500,000,
and
ii) its LCB Index which is a ratio of 1st harmonics of storage modulus to 5th
20 harmonics of storage modulus measured at 125 °C using a rubber process analyzer
according to a LAOS (Large Angles of Oscillation and high Strains) method has a
positive value.
Further, the present invention provides a method for preparing the elastic
4
terpolymer, including the step of continuously feeding a monomer composition
containing 40 to 70 % by weight of ethylene, 20 to 50 % by weight of an alpha-olefin
having 3 to 20 carbon atoms, and 2 to 20 % by weight of a diene to a reactor to perform
copolymerization in the presence of a catalytic composition including a first transition
5 metal compound represented by the following Chemical Formula 1 and a second
transition metal compound represented by the following Chemical Formula 2:
[Chemical Formula 1]
wherein Ri to RB may be the same as or different from each other, and are
each independently hydrogen, an alkyl radical having 1 to 20 carbon atoms, an alkenyl
radical having 2 to 20 carbon atoms, an aryl radical having 6 to 20 carbon atoms, a silyl
radical, an alkylaryl radical having 7 to 20 carbon atoms, an arylalkyl radical having 7
to 20 carbon atoms, or a hydrocarbyl-substituted metalloid radical of a Group IV metal;
of Ri to RB, two different neighboring groups are connected to each other by an
alkylidine radical containing an alkyl having 1 to 20 carbon atoms or an aryl radical
having 6 to 20 carbon atoms to form an aliphatic or aromatic ring;
5 M is a Group IV transition metal; and
Qi and Ch may be the same as or different from each other, and are each
independently a halogen radical, an alkyl radical having 1 to 20 carbon atoms, an
alkenyl radical having 2 to 20 carbon atoms, an aryl radical having 6 to 20 carbon
atoms, an alkylaryl radical having 7 to 20 carbon atoms, an arylalkyl radical having 7 to
10 20 carbon atoms, an alkylamido radical having 1 to 20 carbon atoms, an arylamido
radical having 6 to 20 carbon atoms, or an alkylidene radical having 1 to 20 carbon
atoms.
Hereinafter, an elastic terpolymer and a preparation method thereof will be
15 described in detail according to specific embodiments of the present invention.
First, as used herein, the term "elastic terpolymer" may be defined as follows,
unless otherwise specified. The "elastic terpolymer" refers to any elastic copolymer
(e.g., a cross-linkable random copolymer) obtained by copolymerization of three kinds
of monomers of ethylene, an alpha-olefin having 3 to 20 carbon atoms, and a diene. A
20 representative example of the "elastic terpolymer" is EPDM rubber which is a
copolymer of ethylene, propylene, and a diene. However, it is apparent that this
"elastic terpolymer" refers to not only the copolymer of the three monomers, but also to
any elastic copolymer obtained by copolymerization of one or more monomers
6
belonging to an alpha-olefin and one or more monomers belonging to a diene, together
with ethylene. For example, an elastic copolymer obtained by copolymerization of
ethylene, two kinds of alpha-olefins of propylene and 1-butene, and two kinds of dienes
of ethylidene norbornene and 1,4-hexadiene may also be included in the scope of the
5 "elastic terpolymer", because it is also obtained by copolymerization of three kinds of
monomers belonging to ethylene, alpha-olefin, and diene, respectively.
Meanwhile, according to one embodiment of the present invention, the present
invention provides an elastic terpolymer, in which the elastic terpolymer is a copolymer
of ethylene, an alpha-olefin having 3 to 20 carbon atoms, and a diene, obtained in the
10 presence of a Group IV transition metal catalyst, and
i) its weight average molecular weight measured by GPC is 100,000 to 500,000,
and
ii) its LCB Index which is a ratio of 1st harmonics of storage modulus to 5th
harmonics of storage modulus measured at 125 °C using a rubber process analyzer
15 according to the LAOS (Large Angles of Oscillation and high Strains) method has a
positive value.
The elastic terpolymer of one embodiment, resulting from copolymerization of
three kinds of monomers of ethylene, an alpha-olefin, and a diene within a
predetermined content range, has a relatively high weight average molecular weight of
20 approximately 100,000 to 500,000, or approximately 150,000 to 400,000, or 200,000 to
300,000, as measured by GPC. Such high weight average molecular weight is
achieved due to excellent activity of a Group IV transition metal catalyst, for example,
metallocene-based first and second transition metal compounds of Chemical Formulae
7
1 and 2, described below. As the elastic terpolymer of one embodiment has such a
high molecular weight, the elastic terpolymer, for example, EPDM rubber, exhibits
excellent mechanical properties.
Further, the elastic terpolymer of one embodiment may have a positive LCB
5 Index which is a ratio of 1st harmonics of storage modulus to 5th harmonics of storage
modulus measured at 125 °C using a rubber process analyzer according to the LAOS
(Large Angles of Oscillation and high Strains) method. Preferably, it may have a
value of approximately more than 0 and 5 or less, or approximately 0.01 to 3.5.
The elastic terpolymer of one embodiment satisfying the condition has
10 sufficiently long chain branching to have a positive LCB index, and thus it shows
excellent processability and is suitable for extrusion, and also satisfies excellent
mechanical properties as well as more improved elasticity and flexibility, at the same
time.
Further, the elastic terpolymer of one embodiment may be obtained in the
15 presence of a Group IV transition metal catalyst. In particular, the elastic terpolymer
having the above properties can be prepared with, for example, the characteristic high
productivity and yield of a Group IV metallocene-based transition metal catalyst, and it
has a high molecular weight, thereby satisfying excellent mechanical properties, while
satisfying excellent processability, elasticity, and flexibility at the same time by solving
20 the problems of the conventional EPDM rubber prepared by the Group IV metallocenebased
transition metal catalyst.
Further, the copolymer of ethylene, an alpha-olefin having 3 to 20 carbon
atoms, and a diene may be a copolymer of 40 to 70 % by weight of ethylene, 15 to 55 %
8
by weight of an alpha-olefin having 3 to 20 carbon atoms, and 0.5 to 20 % by weight of
a diene. This copolymer can be prepared by copolymerization while continuously
feeding a monomer composition containing 40 to 70 % by weight of ethylene, 20 to 50 %
by weight of an alpha-olefin having 3 to 20 carbon atoms, and 2 to 20 % by weight of a
5 diene to a reactor in the presence of a catalytic composition. In particular, as each of
the monomers is included at the above ratio, excellent elasticity and flexibility can be
achieved.
Meanwhile, the LCB Index of the elastic terpolymer of one embodiment may
be measured using a rubber process analyzer according to the LAOS (Large Angles of
10 Oscillation and high Strains) method as follows. First, after the elastic terpolymer is
polymerized and prepared, shear storage modulus behavior of each copolymer was
measured using a SIS V-50 rubber process analyzer of SCARABAEUS
INSTRUMENTS SYSTEMS at a predetermined temperature (125 °C) and frequency
(0.2 Hz) while varying strain from 0.2 % to 1250 %. The measured storage modulus
15 was converted into FT to deduce 1st harmonics and 5th harmonics, and then a ratio of
the 1st harmonics of storage modulus to 5th harmonics of storage modulus can be
calculated as the LCB Index.
In this regard, when 1st harmonics and 5th harmonics of the measured storage
modulus are defined as G'i and G'5, respectively, the LCB Index can be expressed as
20 the following Equation 1.
[Equation 1]
LCBIndex = G'i/G'5
The results of calculating the LCB Index of the elastic terpolymer of one
9
embodiment by this method showed that the elastic terpolymer has higher long chain
branching than the EPDM rubber prepared by the Group IV transition metal catalyst
previously used so as to have positive LCB Index. The elastic terpolymer of one
embodiment having high long chain branching and positive LCB Index was found to
5 satisfy excellent elasticity, flexibility, and melt processability as well as excellent
mechanical properties due to high molecular weight.
Further, in the elastic terpolymer of one embodiment, a difference in dynamic
complex viscosity between angular frequencies of 1.0 rad/s and 100.0 rad/s may be
approximately 30,000 Pas or more, and preferably approximately 30,000 to 50,000
10 Pas, as measured at 125 °C using a rubber process analyzer.
Since the elastic terpolymer of one embodiment shows a difference in dynamic
complex viscosity of 30,000 Pas or more between angular frequencies of 1.0 rad/s and
100.0 rad/s, it has a high dynamic complex viscosity at a low angular frequency which
is under practical use, so as to exhibit excellent mechanical properties, and it has a low
15 dynamic complex viscosity at a high angular frequency which is under
extrusion/injection processing so as to exhibit excellent elasticity, flexibility, and melt
processability, and therefore, the elastic terpolymer is suitable for extrusion/injection
processing.
More specifically, the elastic terpolymer may have a dynamic complex
20 viscosity of 30,000 Pas or more, or 33,000 to 150,000 Pas at an angular frequency of
1.0 rad/s. The angular frequency of 1.0 rad/s is similar to the state where the elastic
terpolymer is actually used, and the copolymer has a high dynamic complex viscosity
of 30,000 Pas or more at an angular frequency of 1.0 rad/s, thereby exhibiting
10
excellent mechanical properties.
Further, the elastic terpolymer may have a high dynamic complex viscosity of
5000 Pas or less, or 4500 Pas or less at an angular frequency of 100.0 rad/s. The
angular frequency of 100.0 rad/s is similar to the extrusion/injection processing state,
5 and the copolymer has a low dynamic complex viscosity at an angular frequency of
100.0 rad/s, thereby exhibiting excellent elasticity, flexibility, and melt processability.
The difference in dynamic complex viscosity of the elastic terpolymer can be
measured by using a rubber process analyzer as follows. First, after the elastic
terpolymer is polymerized and prepared, dynamic complex viscosity of each copolymer
10 was measured using an RPA2000 MV 2000E rubber process analyzer of Monsanto Co.
at a predetermined temperature (125 °C) and a frequency range of 0.1-210 rad/s. Then,
a difference between the dynamic complex viscosity at the angular frequency of 1.0
rad/s and the dynamic complex viscosity at the angular frequency of 100.0 rad/s thus
measured can be obtained by an arithmetic calculation.
15 Further, the elastic terpolymer of one embodiment may have a density range to
satisfy the physical properties suitable as EPDM rubber, for example, a density of
approximately 0.840 to 0.895 g/cm3, or approximately 0.850 to 0.890 g/cm3.
Further, the elastic terpolymer of one embodiment may have a Mooney
viscosity (1+4(1)125 °C) range to satisfy physical properties suitable as EPDM rubber,
20 for example, a Mooney viscosity of approximately 1 MU to 180 MU, or approximately
5 MU to 150 MU, or approximately 20 MU to 130 MU. The Mooney viscosity
(1+4(5)125 °C) can be measured in accordance with ASTM D1646-04 using a
11
Monsanto alpha 2000 instrument. If the Mooney viscosity is less than 20 MU, there is
no difference in processability according to long chain branching, and if the Mooney
viscosity is more than 130 MU, the preparation by the present invention is possible, but
polymer productivity is decreased due to high viscosity, which is not beneficial in
5 economic aspects.
Further, in the elastic terpolymer of one embodiment, the alpha-olefin may be
one or more alpha-olefins having 3 to 20 carbon atoms such as propylene, 1-butene, 1-
hexene, 1-octene, 1-pentene, 4-methyl-l-pentene, 1-hexene, 1-heptene, 1-decene, 1-
undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-
10 heptadecene, 1-nonadecene, 9-methyl-l-decene, 11-methyl-ldodecene, 12-ethyl-ltetradecene,
etc. Of them, alpha-olefins having 3 to 10 carbon atoms, such as
representative examples of propylene, 1-butene, 1-hexene, or 1-octene, may be properly
used.
Further, a non-conjugated diene-based monomer may be used as the diene.
15 Specific examples thereof may include 5-1,4-hexadiene, 1,5-heptadiene, 1,6-octadiene,
1,7-nonadiene, 1,8-decadiene, 1,12-tetradecadiene, 3-methyl-l,4-hexadiene, 4-methyl-
1,4-hexadiene, 5-methyl-l,4-hexadiene, 4-ethyl-l,4-hexadiene, 3,3-dimethyl-l,4-
hexadiene, 5-methyl-l,4-heptadiene, 5-ethyl-l,4-heptadiene, 5-methyl-l,5-heptadiene,
6-methyl-l,5-heptadiene, 5-ethyl-1,5-heptadiene, 4-methyl-l,4-octadiene, 5-methyl-
20 l,4-octadiene,4-ethyl-l,4-octadiene, 5-ethyl-l,4-octadiene, 5-methyl-l,5-octadiene, 6-
methyl-l,5-octadiene, 5-ethyl-l,5-octadiene, 6-ethyl-l,5-octadiene, 6-methyl-l,6-
octadiene, 7-methyl-1,6-octadiene, 6-ethyl-l,6-octadiene, 6-propyl-1,6-octadiene, 6-
butyl-l,6-octadiene, 7-methyl-l,6-octadiene, 4-methyl-l,4-nonadiene, ethylidene-2-
12
norbornene, 5-methylene-2-norbornene, 5-(2-propenyl)-2-norbornene, 5-(3-buteny)-2-
norbornene, 5-(l-methyl-2-propenyl)-2-norbornene, 5-(4-pentenyl)-2-norbornene, 5-(lmethyl-
3-buteny)-2-norbornene, 5-(5-hexenyl)-2-norbornene, 5-(l-methyl-4-pentenyl)-
2-norbornene, 5-(2,3-dimethyl-3-buteny)-2-norbornene, 5-(2-ethyl-3-buteny)-2-
5 norbornene, 5-(6-heptenyl)-2-norbornene, 5-(3-methyl-hexenyl)-2-norbornene, 5-(3,4-
dimethyl-4-pentenyl)-2-norbornene, 5-(3 -ethyl-4-pentenyl)-2-norbornene, 5-(7-
octenyl)-2-norbornene, 5-(2-methyl-6-heptenyl)-2 -norbornene, 5-(l,2-dimethyl-5-
hexenyl)-2-norbornene, 5-(5-ethyl-5-hexenyl)-2-norbornene, 5-(l,2,3-trimethyl-4-
pentenyl) -2-norbornene, 5-propylidene-2-norbornene, 5-isopropylidene-2-norbornene,
10 5-butylidene-2-norbornene, 5-isobutylidene-2-norbornene, 2,3-diisopropylidene-5-
norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, and 2-propenyl-2,2-
norbornadiene, and one or more dienes selected therefrom may be used.
Of the dienes, in particular, 5-ethylidene-2-norbornene, 5-methylene-2-
norbornene, or 4-hexadiene may be properly used to prepare the elastic terpolymer,
15 which satisfies the weight average molecular weight and LCB Index of one
embodiment. Meanwhile, 5-vinyl-2-norbornene (VNB) or dicyclopentadiene (DCPD)
which has been used as the diene in the conventional preparation of the elastic
terpolymer has two double bonds, which participate in polymerization reaction to show
a crosslinked polymer structure. Therefore, there are limitations that gel particles are
20 formed during polymerization, or it is difficult to control the molecular weight of the
copolymer and also difficult to control the polymerization reaction.
Meanwhile, according to another embodiment of the present invention,
provided is a method for preparing the above-described elastic terpolymer of one
embodiment. The preparation method of the copolymer may include the step of
continuously feeding a monomer composition containing 40 to 70 % by weight of
ethylene, 20 to 50 % by weight of an alpha-olefin having 3 to 20 carbon atoms, and 2 to
5 20 % by weight of a diene to a reactor to perform copolymerization in the presence of a
catalytic composition including a first transition metal compound represented by the
following Chemical Formula 1 and a second transition metal compound represented by
the following Chemical Formula 2:
[Chemical Formula 1]
10
wherein Ri to RB may be the same as or different from each other, and are
each independently hydrogen, an alkyl radical having 1 to 20 carbon atoms, an alkenyl
14
radical having 2 to 20 carbon atoms, an aryl radical having 6 to 20 carbon atoms, a silyl
radical, an alkylaryl radical having 7 to 20 carbon atoms, an arylalkyl radical having 7
to 20 carbon atoms, or a hydrocarbyl-substituted metalloid radical of a Group IV metal;
of Ri to RB, two different neighboring groups are connected to each other by an
5 alkylidine radical containing an alkyl having 1 to 20 carbon atoms or an aryl radical
having 6 to 20 carbon atoms to form an aliphatic or aromatic ring;
M is a Group IV transition metal; and
Qi and Q2 may be the same as or different from each other, and are each
independently a halogen radical, an alkyl radical having 1 to 20 carbon atoms, an
10 alkenyl radical having 2 to 20 carbon atoms, an aryl radical having 6 to 20 carbon
atoms, an alkylaryl radical having 7 to 20 carbon atoms, an arylalkyl radical having 7 to
20 carbon atoms, an alkylamido radical having 1 to 20 carbon atoms, an arylamido
radical having 6 to 20 carbon atoms, or an alkylidene radical having 1 to 20 carbon
atoms.
15 As confirmed in the following examples, etc., while predetermined amounts of
monomers, that is, approximately 40 to 70 % by weight or approximately 50 to 70 % by
weight of ethylene, approximately 15 to 55 % by weight, or approximately 25 to 45 %
by weight of an alpha-olefin having 3 to 20 carbon atoms, and approximately 0.5 to 20 %
by weight, or approximately 2 to 10 % by weight of a diene are used, each of the
20 monomers is prepared by a continuous polymerization process in the presence of the
transition metal catalyst of Chemical Formula 1 or 2 to obtain the elastic terpolymer of
one embodiment having the above-described high molecular weight range and positive
LCB Index in a high yield and productivity.
15
This is mainly attributed to excellent catalytic activities of the two kinds of
particular catalysts and reactivities of the comonomers. The particular catalysts of the
first and second transition metal compounds exhibit excellent catalytic activities as
Group IV transition metal catalysts, and in particular, they exhibit excellent selectivity
5 and copolymerization reactivity for comonomers such as alpha-olefins and dienes.
Moreover, by using these two kinds of particular catalysts, copolymerization is allowed
to occur while a relatively high content of diene is uniformly distributed in the polymer
chains. It seems that this is because the particular catalysts of Chemical Formulae 1
and 2 very stably maintain rigid five- and six-membered ring structures around metals
10 by a quinoline-based amido group, and therefore they have a structural characteristic
accessible by the monomers. That is, based on the above-described structural
characteristics of the catalysts, the particular catalysts of Chemical Formulae 1 and 2
are able to form a long-chain branched macromer having double bonds during
copolymerization of ethylene and alpha-olefin, in turn, which is copolymerized by
15 reaction with the catalysts to form a long-chain branched elastic terpolymer.
Moreover, using the two kinds of the particular catalysts of the first and second
transition metal compounds, copolymerization is performed in a continuous manner
while continuously feeding a monomer composition containing the monomers to a
polymerization reactor, resulting in more uniform distribution of the comonomer, in
20 particular, the diene, in the polymer chains.
As a result, a long-chain branched elastic terpolymer having a high molecular
weight, in which the monomers are alternately distributed, can be prepared with high
productivity and yield, thereby satisfying the above-described properties of one
16
embodiment, for example, properties of having a weight average molecular weight of
100,000 to 500,000 and a positive LCB Index.
Therefore, according to the preparation method of another embodiment, the
above-described elastic terpolymer of one embodiment can be prepared with high
5 productivity and yield, and this elastic terpolymer satisfies excellent mechanical
properties and more improved elasticity at the same time to be very preferably used as
the EPDM rubber prepared by Group IV transition metal catalysts.
However, if the above-described two kinds of particular catalysts are not used,
or if only one of them is used, or if the content of each monomer, in particular, the
10 content of the diene is out of the above-described proper range, the final elastic
terpolymer may not satisfy the high molecular weight range or the LCB Index range of
one embodiment.
Meanwhile, for the above-described preparation method of the elastic
terpolymer of another embodiment, a more detailed description of the first and second
15 transition metal compounds represented by Chemical Formulae 1 and 2 will be given
below.
First, in Chemical Formulae 1 and 2, hydrocarbyl refers to the monovalent
moiety obtained upon removal of a hydrogen atom from a hydrocarbon, and for
example, it encompasses an alkyl group such as ethyl, etc., or an aryl group such as
20 phenyl, etc.
Further, in Chemical Formulae 1 and 2, metalloid means a semi-metal having
properties of both a metal and a non-metal, and refers to arsenic, boron, silicon,
tellurium, or the like. M refers to, for example, a Group IV transition metal element
17
such as titanium, zirconium, hafnium, or the like.
Of these first and second transition metal compounds, the first transition metal
compound of Chemical Formula 1 may be properly one or more selected from the
group consisting of the following compounds:
wherein R2 and R3 are the same as or different from each other and are each
independently hydrogen or a methyl radical, M is a Group IV transition metal, and Qi
and Q2 are the same as or different from each other and are each independently a
methyl radical, a dimethylimido radical, or a chlorine radical.
5 Further, the second transition metal compound of Chemical Formula 2 may be
properly one or more selected from the group consisting of the following compounds:
wherein R2 and R3 are the same as or different from each other and are each
independently hydrogen or a methyl radical, M is a Group IV transition metal, and Qi
and Q2 are the same as or different from each other and are each independently a
methyl radical, a dimethylimido radical, or a chlorine radical.
5 Meanwhile, the catalytic composition used in the preparation method of
another embodiment may further include one or more co-catalytic compounds selected
from the group consisting of the following Chemical Formula 3, Chemical Formula 4
and Chemical Formula 5, in addition to the above described first and second transition
metal compounds:
10 [Chemical Formula 3]
-[Al(R)-0]nwherein
R's are the same as or different from each other and are each
independently halogen, a hydrocarbon having 1 to 20 carbon atoms, or a halogensubstituted
hydrocarbon having 1 to 20 carbon atoms, and n is an integer of 2 or more;
15 [Chemical Formula 4]
D(R)3
wherein R is the same as defined in Chemical Formula 3, and D is aluminum or
boron; and
[Chemical Formula 5]
20 [L-H]+[ZA4]" or [LftZAJ"
wherein L is a neutral or cationic Lewis acid, H is a hydrogen atom, Z is an
element of Group 13, and A's are the same as or different from each other and are each
independently an aryl group having 6 to 20 carbon atoms or an alkyl group having 1 to
20
20 carbon atoms, in which one or more hydrogen atoms are unsubstituted or substituted
with a halogen, a hydrocarbon having 1 to 20 carbon atoms, an alkoxy, or phenoxy.
In the co-catalytic compound, examples of the compound represented by
Chemical Formula 3 may include methyl aluminoxane, ethyl aluminoxane,
5 isobutyl aluminoxane, butyl aluminoxane, or the like.
Further, examples of the compound represented by Chemical Formula 4 may
include trimethylaluminum, tri ethyl aluminum, triisobutylaluminum, tripropyl aluminum,
tributyl aluminum, dimethylchloroaluminum, triisopropylaluminum, tri-sbutylaluminum,
tricyclopentylaluminum, tripentylaluminum, triisopentylaluminum,
10 trihexylaluminum, trioctylaluminum, ethyl dimethylaluminum, methyl diethylaluminum,
triphenylaluminum, tri-p-tolylaluminum, dimethylaluminummethoxide,
dimethylaluminummethoxide, trimethylboron, triethylboron, triisobutylboron,
tripropylboron, tributylboron or the like, and of them, trimethylaluminum,
triethylaluminum, or triisobutylaluminum may be properly used.
15 The compound represented by Chemical Formula 5 may include a noncoordinating
anion compatible with a cation as the Bronsted acid. Preferred anions
are those containing a single coordination complex having a large size and a semi-metal.
In particular, compounds containing a single boron atom in the anion portion are widely
used. In this regard, salts containing anions including a coordination complex
20 containing a single boron atom are preferably used as the compound represented by
Chemical Formula 5.
As specific examples thereof, examples of trialkylammonium salts may include
trimethylammonium tetrakis(pentafluorophenyl)borate, triethylammonium
21
tetrakis(pentafluorophenyl)borate, tripropylammonium
tetrakis(pentafluorophenyl)borate, tri(n-butyl)ammonium
tetrakis(pentafluorophenyl)borate, tri(2-butyl)ammonium
tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium
5 tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium nbutyltris(
pentafluorophenyl)borate, N,N-dimethylanilinium
benzyltris(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(4-(tbutyldimethylsilyl)-
2,3,5,6-tetrafluorophenyl)borate, N,N-dimethylanilinium tetrakis(4-
triisopropylsilyl)-2,3,5,6-tetrafluorophenyl)borate, N,N-dimethylanilinium
10 pentafluorophenoxytris(pentafluorophenyl)borate, N,N-diethylanilinium
tetrakis(pentafluorophenyl)borate, N,N-dimethyl-2,4,6-trimethylanilinium
tetrakis(pentafluorophenyl)borate, trimethyl ammonium tetrakis(2,3,4,6-
tetrafluorophenyl )b orate, tri ethyl ammonium tetraki s(2,3,4,6-tetrafluorophenyl )b orate,
tripropylammonium tetrakis(2,3,4,6-tetrafluorophenyl)borate, tri(n-butyl)ammonium
15 tetrakis(2,3,4,6-tetrafluorophenyl)borate, dimethyl(t-butyl)ammonium tetrakis(2,3,4,6-
tetrafluorophenyl)b orate, N,N-dimethylanilinium tetrakis(2,3,4,6-
tetrafluorophenyl)b orate, N,N-diethylanilinium tetrakis(2,3,4,6-
tetrafluorophenyl)b orate, N,N-dimethyl-2,4,6-trimethylanilinium tetrakis(2,3,4,6-
tetrafluorophenyl)borate, decyldimethylammonium tetrakis(pentafluorophenyl)borate,
20 dodecyldimethylammonium tetrakis(pentafluorophenyl)borate,
tetradecyldimethylammonium tetrakis(pentafluorophenyl)borate,
hexadecyldimethylammonium tetrakis(pentafluorophenyl)borate,
octadecyldimethylammonium tetrakis(pentafluorophenyl)borate,
22
eicosyldimethylammonium tetrakis(pentafluorophenyl)borate,
methyl didecylammonium tetrakis(pentafluorophenyl)borate,
methyldidodecylammonium tetrakis(pentafluorophenyl)borate,
methylditetradecylammonium tetrakis(pentafluorophenyl)borate,
5 methyldihexadecylammonium tetrakis(pentafluorophenyl)borate,
methyldioctadecylammonium tetrakis(pentafluorophenyl)borate,
methyldieicosylammonium tetrakis(pentafluorophenyl)borate, tridecyl ammonium
tetrakis(pentafluorophenyl)borate, tridodecyl ammonium
tetrakis(pentafluorophenyl)borate, tritetradecylammonium
10 tetrakis(pentafluorophenyl)borate, trihexadecyl ammonium
tetrakis(pentafluorophenyl)borate, trioctadecylammonium
tetrakis(pentafluorophenyl)borate, trieicosylammonium
tetrakis(pentafluorophenyl)borate, decyldi(n-butyl)ammonium
tetrakis(pentafluorophenyl)borate, dodecyldi(n-butyl)ammonium
15 tetrakis(pentafluorophenyl)borate, octadecyldi(n-butyl)ammonium
tetrakis(pentafluorophenyl)borate, N,N-didodecylanilinium
tetrakis(pentafluorophenyl)borate, N-methyl-N-dodecylanilinium
tetrakis(pentafluorophenyl)borate, methyldi(dodecyl)ammonium
tetrakis(pentafluorophenyl)borate, or the like.
20 Further, examples of dialkylammonium salts may include di-(ipropyl)
ammonium tetrakis(pentafluorophenyl)borate, dicyclohexylammonium
tetrakis(pentafluorophenyl)borate, or the like.
Further, examples of carbonium salts may include tropylium
23
tetrakis(pentafluorophenyl)borate, triphenylmethylium
tetraki s(pentafluorophenyl )b orate, b enzene(di azonium)
tetrakis(pentafluorophenyl)borate, or the like.
Meanwhile, in the above-described preparation method of the elastic
5 terpolymer, the catalytic composition containing the above-described first and second
transition metal compounds, and optionally the co-catalytic compound may be prepared
by, for example, a method including the steps of contacting the first and second
transition metal compounds with the co-catalytic compound of Chemical Formula 3 or
Chemical Formula 4 to prepare a mixture; and adding the co-catalytic compound of
10 Chemical Formula 5 to the mixture.
Further, in the catalytic composition, a molar ratio of the first transition metal
compound to the second transition metal compound may be approximately 10:1 to 1:10,
a molar ratio of the total transition metal compound of the first and second transition
metal compounds to the co-catalytic compound of Chemical Formula 3 or Chemical
15 Formula 4 may be approximately 1:5 to 1:500, and a molar ratio of the total transition
metal compound to the co-catalytic compound of Chemical Formula 5 may be
approximately 1:1 to 1:10.
Further, in the preparation method of the elastic terpolymer, the catalytic
composition may additionally include a reaction solvent, and examples of the reaction
20 solvent may include hydrocarbon-based solvents such as pentane, hexane, or heptane,
etc., or aromatic solvents such as benzene, toluene, etc., but are not limited thereto.
As described above, alpha-olefin contained in the monomer composition may
include propylene, 1-butene, 1-hexene, 1-octene, 1-pentene, 4-methyl-l-pentene, 1-
24
hexene, 1-heptene, 1-decene, 1-undecene, 1-dodecene, or the like, and as the diene, a
non-conjugated diene-based monomer may be used. Of them, as the monomers
typically used in the preparation of EPDM rubber, for example, propylene as the alphaolefin
and a non-conjugated diene-based monomer such as 5-ethylidene-2-norbornene,
5 1,4-hexadiene, or dicyclopentadiene as the diene, may be properly used.
Further, in the above-described preparation method of the copolymer of
another embodiment, the copolymerization step may be performed at a temperature of
approximately 100 to 170 °C, or at a temperature of approximately 100 to 160 °C. If
the copolymerization temperature is too low, it is difficult to prepare an elastic
10 terpolymer in which the three kinds of monomers are alternately distributed uniformly.
If the polymerization temperature is too high, thermal decomposition of the monomers
or the prepared copolymer may occur. Further, copolymerization may be performed
by solution polymerization, in particular, by a continuous solution polymerization
method. In this regard, the above-described catalytic composition may be dissolved in
15 the solution, and thus used in the form of homogeneous catalyst.
For the continuous solution polymerization, the copolymerization step may be
performed by feeding the above-described monomer composition, the catalytic
composition containing the first and second transition metal compounds, and optionally
the cocatalyst in the solution state to a reactor, and the copolymerization step may be
20 continuously performed by continuously discharging the copolymerized elastic
terpolymer from the reactor.
By this continuous solution polymerization, a long-chain branched elastic
terpolymer can be more effectively obtained with high productivity and yield.
25
[ADVANTAGEOUS EFFECTS!
According to the present invention, as described above, a long-chain branched
elastic terpolymer which has excellent processability and more improved elasticity and
5 flexibility to be very preferably used as EPDM rubber can be prepared by a Group IV
transition metal catalyst.
Further, according to the present invention, a method for preparing a copolymer
capable of preparing the long-chain branched elastic terpolymer with high productivity
and yield is provided.
10 Since the long-chain branched elastic terpolymer obtained according to the
present invention overcomes the limitations of the previously known EPDM rubber
which is prepared by a Group IV metallocene-based transition metal catalyst, and
satisfies excellent elasticity and flexibility as well as other physical properties, it can be
very preferably used as EPDM rubber while bringing out the characteristic advantage
15 of the Group IV transition metal catalyst.
[BRIEF DESCRIPTION OF DRAWINGS]
FIG. 1 is a graph showing an LCB Index of elastic terpolymers prepared in
Examples and Comparative Examples.
20
[DETAILED DESCRIPTION OF THE EMBODFMENTS]
26
The present invention will be described in more detail in the following
examples. However, these examples are for illustrative purposes only and are not
intended to limit the scope of the present invention.
5
Synthesis of all ligands and catalysts was performed by standard Schlenk and
glovebox techniques under a nitrogen atmosphere to avoid contact with air and
moisture, and organic solvents used in reactions were purified by a standard method
before use. The structures of the synthesized ligands and catalysts were confirmed by
10 400 MHz Nuclear Magnetic Resonance (NMR) Spectroscopy and X-ray Spectroscopy.
In the following examples, as first and second transition metal compounds,
[(l,2,3,4-tetrahydroquinolin-8-yl)tetramethylcyclopentadienyl-eta5,kapa-N]titanium
dimethyl and [(2-methylindolin-7-yl)tetramethylcyclopentadienyl-eta5,kapa-N]titanium
dimethyl were used, respectively. As a co-catalytic compound, N,N-
15 dimethylanilinium tetrakis(pentafluorophenyl)borate and triisobutylaluminum were
used. The first and second transition metal compounds were prepared and used in the
same manner as in Examples 2 and 14 of Korean Patent No. 0,976,131, and the cocatalytic
compound was prepared and used in the same manner as in Example 9 of
Korean Patent No. 0,820,542.
20
Preparation of elastic terpolymer of ethylene,
propylene, and 5-ethylidene-2-norbornene
Terpolymerization of ethylene, propylene, and 5-ethylidene-2-norbornene was
27
continuously performed using a 2 L-pressure reactor. Hexane as a polymerization
solvent was continuously fed to the bottom of the reactor at a feed rate of 6.7 kg per
hour, and the polymerization solution was continuously discharged from the top of the
reactor.
5 As the first and second transition metal compounds, the above-described
[(1,2,3,4-tetrahydroquinolin-8-yl)tetramethylcyclopentadienyl-eta5,kapa-N]titanium
dimethyl and [(2-methylindolin-7-yl)tetramethylcyclopentadienyl-eta5,kapa-N]titanium
dimethyl dissolved in hexane were used, and fed to the reactor at a rate of 24 to 60
umol per hour. Further, as the co-catalytic compound, the above-described N,N-
10 dimethylanilinium tetrakis(pentafluorophenyl)borate dissolved in toluene was used, and
fed to the reactor at a rate of 105 to 270 umol per hour. Further, as the additional cocatalytic
compound, the above-described triisobutylaluminum dissolved in hexane was
used, and fed to the reactor at a rate of 1800 to 3200 umol per hour.
As the monomers, ethylene at a rate of 890 to 900 g per hour, propylene at a
15 rate of 450 to 550 g per hour, and 5-ethylidene-2-norbornene at a rate of 80 to 250 g per
hour were continuously fed to the reactor to perform the copolymerization.
The copolymerization temperature in the reactor was controlled between 130 to
160 °C while 0.5 mL/min of the feed rate of 5-ethylidene-2-norbornene was increased
from 1 mL/min at around 160 °C.
20 Under the above-described conditions, copolymerization was performed by
continuous solution polymerization to prepare elastic terpolymers of Examples 1 to 6 in
the form of a homogeneous solution in a continuous manner, and the polymerization
solutions continuously discharged from the top of the reactor were dried under reduced
28
pressure in a 60 °C vacuum oven after termination of the polymerization reaction under
ethanol, and finally, copolymers of Examples 1 to 6 were prepared.
Commercialized elastic terpolymer of
5 ethylene, propylene, and 5-ethylidene-2-norbornene
V-2502 of Exxon, which is a commercialized EPDM rubber known to be
prepared by a metallocene catalyst, was used as an elastic terpolymer of Comparative
Example 1, and 3722, 4520, 4640, 4725, 4770, and 4570 of DOW, which are also
commercialized EPDM rubber known to be prepared by the metallocene catalyst, were
10 used as elastic terpolymers of Comparative Examples 2-7, respectively.
Commercialized elastic terpolymer of ethylene,
propylene, and 5-ethylidene-2-norbornene
KEP-2320 of Kumho Polychem, which is a commercialized EPDM rubber
15 known to be prepared by a Ziegler-Natta catalyst, was used as an elastic terpolymer of
Comparative Example 8.
Measurement of LCB Index
Behaviors of shear storage modulus of the copolymers obtained in the
20 examples and comparative examples were measured using a SIS V-50 rubber process
analyzer of SCARABAEUS INSTRUMENTS SYSTEMS at a predetermined
temperature (125 °C) and frequency (0.2 Hz) while varying strain from 0.2 % to
1250 %. The measured storage modulus was converted into FT to derive 1st
29
harmonics and 5 harmonics, and then a ratio of the Is harmonics of storage modulus
to 5th harmonics of storage modulus was calculated as the LCB Index, and are shown in
the following Table 1 and FIG. 1.
In this regard, when 1st harmonics and 5th harmonics of the measured storage
5 modulus are defined as G'i and G'5, respectively, the LCB Index can be expressed as
the following Equation 1.
[Equation 1]
LCB Index = G'i/G'5
10 Measurement of dynamic complex viscosity
Dynamic complex viscosity was measured according to ASTM D6204-01
using a rubber process analyzer. RPA2000 MV 2000E instrument model of Monsanto
Co. was used, and as a measurement sample, the antioxidant (Irganox 1076)-treated
copolymer sample was prepared in a sheet form using a press mold, and dynamic
15 complex viscosity thereof was measured at 125 °C and 7 % strain and at a frequency
range of 0.1-210 rad/s. In each copolymer of the examples and comparative examples,
the dynamic complex viscosity with respect to change in the angular frequency is
shown in the following Tables 2 and 3.
20 Measurement of Mooney viscosity
Mooney viscosity of the copolymers obtained in the examples and comparative
examples was measured at 125 °C in accordance with ASTM D1646-04 using a
Monsanto alpha 2000 instrument, and are shown in the following Table 1.
30
Measurement of weight average molecular
weight
Weight average molecular weight of the copolymers obtained in the examples
5 and comparative examples was measured using PL-GPC 220 of Polymer Laboratory,
which was equipped with 3 linear mixed bed columns, and are shown in the following
Table 2. At this time, the measurement was performed at a temperature of 160 °C
using 1,2,4-trichlorobenzene as a solvent at a flow rate of 1.0 ml/min.
frequency of 1.0 rad/s and a value of dynamic complex viscosity at angular frequency
of 100.0 rad/s
frequency of 1.0 rad/s and a value of dynamic complex viscosity at angular frequency
of 100.0 rad/s
10 Referring to Table 1 and FIG. 1, it was found that the copolymers of Examples
1 to 6 showed positive LCB Index values, but the copolymers of Comparative
Examples 1 to 7 showed negative LCB Index values.
Referring to Tables 2 and 3, it was found that the copolymers of Examples 1 to
6 showed the dynamic complex viscosity difference between angular frequencies of 1.0
rad/s and 100.0 rad/s of 30,000 Pas or more, indicating a great difference in the
dynamic complex viscosity between the elastic terpolymers in practical use and those
5 under an extrusion/injection processing state.
These results suggest that the elastic terpolymers of Examples 1 to 6 have
higher long chain branching to exhibit excellent mechanical properties and melt
processability, thereby having superior elasticity, flexibility, and processability to those
of the comparative examples.

WE CLAIMS:-
An elastic terpolymer, wherein the elastic terpolymer is a copolymer of
ethylene, an alpha-olefin having 3 to 20 carbon atoms, and a diene, obtained in the
5 presence of a Group IV transition metal catalyst, wherein
i) its weight average molecular weight measured by GPC is 100,000 to 500,000,
and
ii) its LCB Index which is a ratio of 1st harmonics of storage modulus to 5th
harmonics of storage modulus measured at 125 °C using a rubber process analyzer
10 according to a LAOS (Large Angles of Oscillation and high Strains) method has a
positive value.
[Claim 2]
The elastic terpolymer of claim 1, wherein the LCB Index is more than 0 and 5
15 or less.
[Claim 3]
The elastic terpolymer of claim 1, wherein a difference in dynamic complex
viscosity between angular frequencies of 1.0 rad/s and 100.0 rad/s is 30,000 Pas or
20 more, as measured at 125 °C using a rubber process analyzer.
[Claim 4]
The elastic terpolymer of claim 1, wherein the dynamic complex viscosity at
the angular frequency of 1.0 rad/s is 30,000 Pas or more.
[Claim 5]
5 The elastic terpolymer of claim 1, wherein the dynamic complex viscosity at
the angular frequency of 100.0 rad/s is 5000 Pas or less.
[Claim 6]
The elastic terpolymer of claim 1, wherein the copolymer of ethylene, the
10 alpha-olefin having 3 to 20 carbon atoms, and the diene is a copolymer of 40 to 70 %
by weight of ethylene, 15 to 55 % by weight of the alpha-olefin having 3 to 20
carbon atoms and 0.5 to 20 % by weight of the diene.
[Claim 7]
15 The elastic terpolymer of claim 1, wherein the elastic terpolymer has a density
of 0.840 to 0.895 g/cm3.
[Claim 8]
The elastic terpolymer of claim 1, wherein the elastic terpolymer has Mooney
20 viscosity (l+4(a)125 °C) of 5 to 180.
[Claim 9]
The elastic terpolymer of claim 1, wherein the elastic terpolymer has a
molecular weight distribution of 2 to 4.
[Claim 10]
5 The elastic terpolymer of claim 1, wherein the alpha-olefin is one or more
selected from the group consisting of propylene, 1-butene, 1-hexene, and 1-octene, and
the diene is one or more selected from the group consisting of 5-ethylidene-2-
norbornene, 5-methylene-2-norbornene, and 4-hexadiene.
10 [Claim 11]
A method for preparing the elastic terpolymer of claim 1, comprising the step
of continuously feeding a monomer composition containing 40 to 70 % by weight of
ethylene, 20 to 50 % by weight of the alpha-olefin having 3 to 20 carbon atoms, and 2
to 20 % by weight of the diene to a reactor to perform copolymerization in the presence
15 of a catalytic composition including a first transition metal compound represented by
the following Chemical Formula 1 and a second transition metal compound represented
by the following Chemical Formula 2:
[Chemical Formula 1]
wherein Ri to RB are the same as or different from each other, and are each
5 independently hydrogen, an alkyl radical having 1 to 20 carbon atoms, an alkenyl
radical having 2 to 20 carbon atoms, an aryl radical having 6 to 20 carbon atoms, a silyl
radical, an alkylaryl radical having 7 to 20 carbon atoms, an arylalkyl radical having 7
to 20 carbon atoms, or a hydrocarbyl-substituted metalloid radical of a Group IV metal;
of Ri to RB, two different neighboring groups are connected to each other by an
10 alkylidine radical containing an alkyl having 1 to 20 carbon atoms or an aryl radical
having 6 to 20 carbon atoms to form an aliphatic or aromatic ring;
M is a Group IV transition metal; and
Qi and Ch are the same as or different from each other, and are each
independently a halogen radical, an alkyl radical having 1 to 20 carbon atoms, an
39
alkenyl radical having 2 to 20 carbon atoms, an aryl radical having 6 to 20 carbon
atoms, an alkylaryl radical having 7 to 20 carbon atoms, an arylalkyl radical having 7 to
20 carbon atoms, an alkylamido radical having 1 to 20 carbon atoms, an arylamido
radical having 6 to 20 carbon atoms, or an alkylidene radical having 1 to 20 carbon
5 atoms.
[Claim 12]
The method of claim 11, wherein the first transition metal compound is one or
more selected from the group consisting of the following compounds:
40
wherein R2 and R3 are the same as or different from each other and are each
independently hydrogen or a methyl radical, M is a Group IV transition metal, and Qi
and Q2 are the same as or different from each other and are each independently a
5 methyl radical, a dimethylimido radical, or a chlorine radical.
[Claim 13]
The method of claim 11, wherein the second transition metal compound is one
or more selected from the group consisting of the following compounds:
41
wherein R2 and R3 are the same as or different from each other and are each
independently hydrogen or a methyl radical, M is a Group IV transition metal, and Qi
5 and Q2 are the same as or different from each other and are each independently a
methyl radical, a dimethylimido radical, or a chlorine radical.
[Claim 14]
42
The method of claim 11, wherein the catalytic composition further includes one
or more co-catalytic compounds selected from the group consisting of the following
Chemical Formula 3, Chemical Formula 4, and Chemical Formula 5:
[Chemical Formula 3]
5 -[Al(R)-0]nwherein
R's are the same as or different from each other and are each
independently a halogen, a hydrocarbon having 1 to 20 carbon atoms, or a halogensubstituted
hydrocarbon having 1 to 20 carbon atoms, and n is an integer of 2 or more;
[Chemical Formula 4]
10 D(R)3
wherein R is the same as defined in Chemical Formula 3, and D is aluminum or
boron; and
[Chemical Formula 5]
[L-H]+[ZA4]" or [L]+[ZA4]"
15 wherein L is a neutral or cationic Lewis acid, H is a hydrogen atom, Z is an
element of Group 13, and A's are the same as or different from each other and are each
independently an aryl group having 6 to 20 carbon atoms or an alkyl group having 1 to
20 carbon atoms, in which one or more hydrogen atoms are unsubstituted or substituted
with a halogen, a hydrocarbon having 1 to 20 carbon atoms, an alkoxy, or a phenoxy.
20
[Claim 15]
The method of claim 11, wherein the alpha-olefin is one or more selected from
the group consisting of propylene, 1-butene, 1-hexene, and 1-octene, and the diene is
one or more selected from the group consisting of 5-ethylidene-2-norbornene, 5-
methylene-2-norbornene, and 4-hexadiene.
[Claim 16]
5 The method of claim 11, wherein copolymerization is performed while
continuously feeding the monomer composition, the first and second transition metal
compounds, and the cocatalyst in a solution state to a reactor.
[Claim 17]
10 The method of claim 16, wherein the copolymerization step is continuously
performed while continuously discharging the copolymerized elastic terpolymer from
the reactor.
[Claim 18]
15 The method of claim 11, wherein the copolymerization step is performed at a
temperature of 100 to 170 °C.