DESCRIPTION
CROSSLINKED PRODUCT, METHOD FOR PRODUCING THE SAME AND THE USE
THEREOF, AND ETHYLENE COPOLYMER
5
TECHNICAL FIELD
[0001]
The present invention relates to a method for producing a
crosslinked product, a crosslinked product, use thereof, an
10 ethylene copolymer, and an ethylene copolymer composition.
BACKGROUND ART
[0002]
An ethylene ex-olefin copolymer has been conventionally used
15 in various applications.
[0003]
For example, it is known that a crosslinked product obtained
by crosslinking the ethylene ex-olefin copolymer after being melt
molded, is used in electric cable coverings and wall papers (See
20 Patent Documents 1 and 2).
[0004]
,-.,
Further, since a crosslinked foamed product using an
ethylene ex-olefin copolymer has a high mechanical strength and
is light weight and flexible, it is used in interior and exterior
fi
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2
materials for construction, automotive parts such as door glass
run channels, packaging materials, daily necessities and the like.
Attempts have also been made to use it for footwear or footwear
parts, such as soles (mainly, midsoles) for sports shoes and the
5 like. When used in footwear or footwear parts, among others,
requirements such as being light weight and having an excellent
durability need to be met. Patent Document 3 discloses an
ethylene ex-olefin copolymer having a low specific gravity and low
compression set, a crosslinked molded article made therefrom, and
10 a footwear part made therefrom. Further, Patent Document 4
discloses a crosslinked molded article obtained from an
ethylene/ex-olefin copolymer composition, having an improved
compression set.
15 CITATION LIST
PATENT DOCUMENTS
',
ii [0005]
i,,'
11
Patent Document 1: Japanese Laid-Open Patent Publication
i.:
f,
~; No. H06-87990
i1
\·
:·' 20 Patent Document 2: Japanese Laid-Open Patent Publication
No. 2013-204211
Patent Document 3: Japanese Laid-Open Patent Publication
No. 2008-308619
Patent Document 4: International Publication No.
SF-2899
3
2013/039850 pamphlet
SUMMARY OF THE INVENTION
PROBLEMS TO BE SOLVED BY THE INVENTION
5 [0006]
The investigation by the present inventors has revealed that,
when a conventional ethylene copolymer is melt molded and
crosslinked to produce a molded article, there are cases where
the resulting molded article has a poor appearance due to problems
10 in moldabili ty. Further, there are cases where an effort to widen
the molecular weight distribution of the polymer in order to
improve the moldability results in poor physical properties of
the molded article. Further, in the crosslinked molded article
obtained from a composition of an ethylene copolymer having a low
15 vinyl group content, such as the ethylene/a-olefin copolymer
disclosed in Patent Document 4, there are cases where the phys,ical
properties thereof such as tensile strength and tear strength do
not meet the requirements.
[0007]
20 Conventionally, when such a material for the crosslinked
molded article is used to produce parts for footwear or clothing,
a method has been mainly used in which a compound containing a
crosslinking agent and a foaming agent is molded to produce a
foamable sheet, and the obtained sheet is cut and placed in a mold
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to obtain a primary foamed product, which is then subjected to
compression molding, as required, to impart a pre-determined
shape.
[0008]
5 From the viewpoint of reducing the production cost, on the
other hand, it is preferred that the product be capable of being
produced by injection molding, transfer molding or the like. It
is particularly preferred that the product be capable of being
produced by injection molding or transfer molding, because number
10 of people and steps required for the production can be reduced.
However, the investigation by the present inventors has revealed
that, when a composition containing single ethylene/a-olefin
copolymer is subjected to crosslinking foaming, for example by
injection molding, dimensional variations among a plurality of
15 the resulting molded articles are observed.
[0009]
An object of the present invention is to provide a method
for producing a crosslinked product excellent in moldability and
in physical properties and appearance after being crosslinked,
20 using an ethylene a-olefin copolymer; and to provide an ethylene
a-olefin copolymer which is formed into a crosslinked product
having an excellent moldabili ty and excellent physical properties.
Another object of the present invention is to provide a foamed
product having sufficient mechanical strength, to reduce
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5
dimensional variations among the obtained foamed products, and
to provide an ethylene ~-olefin copolymer which is formed into
the foamed product, when producing the crosslinked foamed product
through a molding step such as injection molding or a transfer
5 molding.
MEANS FOR SOLVING THE PROBLEMS
[0010]
The present invention relates to the following items [1]
10 to [14].
[1] A method for producing a crosslinked product, comprising
the steps of:
melt molding an ethylene copolymer (A) or a resin
composition containing the ethylene copolymer (A); and
15 carrying out crosslinking;
wherein the ethylene copolymer (A) contains a
constitutional unit derived from ethylene and a constitutional
unit derived from an ~-olefin having from 3 to 20 carbon atoms,
and satisfies all of the following requirements (1), (2) and (3):
20 (1) a vinyl group content per 1,000 carbon atoms as measured by
1H-NMR is 0.06 or more and one or less;
.:.: 'I
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(2) a ratio MFR10 /MFR2 . 16 is 8.5 or more and 50 or less; and
I
:1 (3) a density d is 850 kg/m3 or more and 920 kg/m3 or less
>I
'!
(wherein, MFR10 represents a melt flow rate (g/10 min) as measured
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6
in accordance with ASTM 01238 at a load of 10 kg and at a temperature
of 190°C; and MFR2 . 16 represents a melt flow rate (g/10 min) as
measured in accordance with ASTM 01238 at a load of 2.16 kg and
at a temperature of 190°C).
5 [ 2] The method for producing a crosslinked product according
to the item [1], wherein the ethylene copolymer (A) further
satisfies the following requirement (4):
(4) MFR2 . 16 is within the range of from 0.01 to 200 g/10 min.
[3] The method for producing a crosslinked product according
10 to the item [1] or [2], wherein the ethylene copolymer (A) is an
ethylene copolymer (Al) obtained by using ethylene and a-olefin
alone as monomers.
[ 4] The method for producing a crosslinked product according
to any one of the items [1] to [3], further comprising the step
15 of carrying out foaming.
[5] The method for producing a crosslinked product accor;ding
to any one of the items [1] to [3], wherein the step of melt molding
is carried out·by injection molding or transfer molding, and
wherein the method further comprises the step of carrying out
20 foaming.
[ 6] A crosslinked product obtained by the method for producing
a crosslinked product according to any one of the items [1] to
[ 5] .
ii
II ;.]
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7
[7] A laminated molded article comprising a layer composed of
one or more kinds of raw materials selected from the group
consisting of polyolefin, polyurethane, rubber, leather and
artificial leather, and the crosslinked product according to i tern
5 [6], wherein the layer composed of one or more kinds of raw
materials and the crosslinked product are laminated together.
[8] The laminated molded article according to the item [7],
wherein the laminated molded article is a footwear part.
[9] The laminated molded article according to the item [8],
10 wherein the footwear part is a midsole, an inner sole, or a sole.
[10] An ethylene copolymer (A) which contains a constitutional
unit derived from ethylene and a constitutional unit derived from
an ex-olefin having from 3 to 20 carbon atoms, and which satisfies
all of the following requirements (1), (2) and (3):
15 (1) a vinyl group content per 1,000 carbon atoms as measured by
1H-NMR is 0.06 or more and one or less;
(2) a ratio MFR10/MFR2 . 16 is 8.5 or more and 50 or less;. and
(3) a density d is 850 kg/m3 or more and 920 kg/m3 or less
(wherein, MFR10 represents a melt flow rate (g/10 min) as measured
20 in accordance with ASTM D12 3 8 at a load of 10 kg and at a temperature
of 190"C; and MFR2 . 16 represents a melt flow rate (g/10 min) as
measured in accordance with ASTM D1238 at a load of 2.16 kg and
at a temperature of 190"C).
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[11) The ethylene copolymer (A) according to the item [10),
wherein the ethylene copolymer (A) further satisfies the following
requirement ( 4) :
(4) MFR2 . 16 is within the range of from 0.01 to 200 g/10 min.
5 [12) The ethylene copolymer (A) according to the item [10) or
[11), wherein the ethylene copolymer (A) is an ethylene copolymer
(Al) obtained by using ethylene and ~-olefin alone as monomers.
[13) An ethylene copolymer composition comprising the ethylene
copolymer (A) according to any one of the items [10) to [12) and
~ 10 a crosslinking agent (C).
[14) The ethylene copolymer composition according to the item
,.
[13), further comprising a foaming agent (D).
EFFECT OF THE INVENTION
15 [0011)
The method for producing a crosslinked product acco~ding
to the present invention is capable of providing a crosslinked
product having a good moldability and an excellent mechanical
strength.
20 [0012)
Further, the present method is capable of providing a foamed
product which is light weight and excellent in mechanical strength,
with an excellent productivity; as well as providing crosslinked
molded articles whose dimensional variations between individual
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9
products are small.
[0013]
The crosslinked product of the present invention is
excellent in appearance and mechanical strength.
5 [0014]
The crosslinked foamed product of the present invention is
excellent in mechanical strength, light weight and flexible, and
excellent in durability. Therefore, the crosslinked foamed
product of the present invention and a laminated molded article
10 using the same is suitably used for footwear parts.
[0015]
Further, the ethylene copolymer (A) of the present invention
is suitably used for producing the above mentioned crosslinked
product or crosslinked foamed product. The ethylene copolymer
15 (A) of the present invention is excellent in crosslinking
properties, and when used for producing a crosslinked product,
the obtained crosslinked product has an excellent moldability.
When used for producing a crosslinked foamed product, the obtained
foamed product has a good dimensional stability, and an excellent
20 productivity is obtained. Further, the obtained crosslinked
product or the crosslinked foamed product has an excellent
mechanical strength.
MODE FOR CARRYING OUT THE INVENTION
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10
[0016]
Hereinafter, the present invention will be described in
detail.
[0017]
5
In the present description, unless otherwise specified, the
crosslinked product includes both an unfoamed crosslinked product
and foamed crosslinked product. In the production of the
crosslinked product of the present invention, an ethylene
10 copolymer (A) is used as an essential component, and the ethylene
copolymer (A) may be used alone, or a resin composition containing
the ethylene copolymer (A) may be used. In addition to the
ethylene copolymer (A), another resin component (B), a
crosslinking agent (C), a foaming agent (D) and optional
15 components such as additives are used in the resin composition,
as necessary.
[0018]
Ethylene copolymer (A)
The ethylene copolymer (A) according to the present
,,
::! 20 invention contains a constitutional unit derived from ethylene
and a constitutional unit derived from an a-olefin having from
3 to 20 carbon atoms, and satisfies all of the following
requirements (1), (2) and (3). Further, the ethylene copolymer
(A) according to the present invention preferably satisfies the
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SF-2899
11
following requirement (4), in addition to the following
requirements (1), (2), and (3).
(1) The vinyl group content per 1,000 carbon atoms as measured
by 1H-NMR is 0.06 or more and one or less.
5 (2) The ratio MFR10 /MFR2.16 is 8.5 or more and 50 or less.
( 3) The density d is 850 kg/m3 or more and 920 kg/m3 or less.
( 4) MFR2.16 is within the range of from 0.01 to 200 g/10 min.
[0019]
In the present invention, MFR10 represents a melt flow rate
10 (g/10 min) as measured in accordance with ASTM Dl238 at a load
of 10 kg and at a temperature of 190°C; and MFR2.16 represents a
melt flow rate (g/10 min) as measured in accordance with ASTM Dl238
at a load of 2.16 kg and at a temperature of 190°C.
[0020]
15 The ethylene copolymer (A) according to the present
invention contains a constitutional l)nit derived from ethy,lene
and a constitutional unit derived from an ex-olefin having from
3 to 20 carbon atoms. The ethylene copolymer (A) of the present
invention is not particularly limited as long as it contains a
20 constitutional unit derived from ethylene and a constitutional
unit derived from an ex-olefin having from 3 to 20 carbon atoms.
The ethylene copolymer (A) may be a copolymer composed solely of
ethylene and an ex-olefin having from 3 to 20 carbon atoms, and
it may also contain a constitutional unit derived from compounds
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12
other than ethylene and a-olefins.
[0021]
Examples of the a-olefin having from 3 to 20 carbon atoms
include propylene, 1-butene, 1-pentene, 3-methyl-1-butene,
5 4-methyl-1-pentene, 1-hexene, 1-octene, 1- decene, 1-dodecene,
1-tetradecene and the like. The a-olefin having from 3 to 20
carbon atoms is preferably an a-olefin having from 3 to 10 carbon
atoms. The a-olefin having from 3 to 20 carbon atoms, which is
a copolymerization component, may be of one kind alone, or of two
10 or more kinds.
[0022]
Further, the ethylene copolymer (A) according to the present
invention may contain a constitutional unit derived from a
non-conjugated diene containing a vinyl group. Examples of the
15 non-conjugated diene include vinylnorbornene. In the present
invention., the ethylene copolymer (A) is prefe:~:ably com]:]osed
solely of a constitutional unit derived from ethylene and a
constitutional unit derived from an ex-olefin having from 3 to 20
carbon atoms, from the viewpoint that the polymer can be easily
20 produced and that the amount of gel in the polymer is reduced.
[0023]
In the ethylene copolymer (A) according to the present
invention, the ratio of the constitutional unit derived from
ethylene and the constitutional unit derived from an ex-olefin
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13
having from 3 to 20 carbon atoms may be selected as appropriate
so as to satisfy the density range described in the requirement
,, , . .,
'i ( 3) . Usually, the ratio of the constitutional unit derived from
:·!
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ethylene is from 50 to 95% by mole, based on 100% by mole of the
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i
total amount of the constitutional unit derived from ethylene and
;;
::;
~:
~ i the constitutional unit derived from an ex-olefin. The lower limit
\l ,;:,,
:': of the amount of the constitutional unit derived from ethylene
is preferably 60% by mole, more preferably 7 5% by mole, and still
more preferably 80% by mole.
10 [0024]
Vinyl group content
The ethylene copolymer (A) according to the present
invention has a vinyl group content per 1,000 carbon atoms as
measured by 1H-NMR of 0.06 or more and one or less (requirement
15 ( 1) ) .
The lower limit of the vinyl group content per 1, 000 ca,rbon
atoms of the ethylene copolymer (A) according to the present
invention is usually 0. 0 6, preferably 0. 07, more preferably 0. 08,
and still more preferably 0. 0 9. The upper limit of the vinyl group
20 content per 1,000 carbon atoms of the ethylene copolymer (A)
according to the present invention is 1, preferably 0. 50, and more
preferably 0. 25. The vinyl group content within the above range
is preferred, from the viewpoint that it improves the mechanical
strength of the resulting molded article. The reason for the fact
SF-2899
14
that the molded article obtained from the ethylene polymer (A)
of the present invention has an excellent mechanical strength,
due to the high vinyl group content of the polymer, will be
discussed in detail also in the section describing the production
5 of the crosslinked product. The specific measurement method of
the vinyl group content and the vinylidene group content described
later will be described in detail in the section explaining the
measurement method in Examples described later.
[0025]
10 Vinylidene group content
The ethylene copolymer (A) according to the present
invention usually has a vinylidene group content per 1, 000 carbon
atoms as measured by 1H-NMR of 0.05 or more and 1.00 or less, but
not particularly limited thereto. The lower limit of the
15 vinylidene group content per 1,000 carbon atoms of the ethylene
copolymer (A) is usually 0. 05, preferably 0. 06, and .more
preferably 0. 07. The upper limit thereof is usually 1. 00,
preferably 0.50, and more preferably 0.35.
[0026]
:)
•I 20
The ethylene copolymer (A) according to the present
invention has a ratio MFR10 /MFR2 . 16 of 8.5 or more and 50 or less
(requirement (2)).
The ratio MFR10 /MFR2 . 16 of the ethylene copolymer (A)
i.!
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SF-2899
15
according to the present invention is usually 8. 5 or more,
preferably greater than 8. 5, more preferably 8. 6 or more, and still
more preferably 8. 7 or more. The upper limit of the ratio
MFR10 /MFR2 . 16 of the ethylene copolymer (A) is usually 50,
5 preferably 25, more preferably 13, and still more preferably 12.
[0027]
As used herein, MFR10 represents the melt flow rate (g/10
min) measured at a load of 10 kg and at a temperature of 190°C;
and MFR2 •16 represents the melt flow rate (g/10 min) measured at
i! 10 a load of 2. 16 kg and at a temperature of 190 °C. The ratio
,ii,
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t'
I:
MFR10/MFR2 . 16 is a value considered to serve as one of the indices
11
representing the degree of long chain branching of the copolymer.
i!lI [0028J
,I
il If the value of the ratio MFR10 /MFR2 . 16 of the ethylene
il
" 15 copolymer is less than 8. 5, for example, when a composition
containing the ethylene copolymer along with components such as
r
a foaming agent and a cross linking agent and the like is subjected
,,,,
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to injection molding and foaming to produce a crosslinked foamed
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20
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product, there are cases where the obtained crosslinked foamed
product has a low shape accuracy, and the dimensional variations
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among the crosslinked foamed products are observed. If the value
II
' of the ratio MFR10 /MFR2 . 16 of the ethylene copolymer is too large,
exceeding 50, although the degree of dimensional variations is
slightly improved, the physical properties of the obtained foamed
5
SF-2899
16
molded article such as strength may be reduced, and therefore it
is not preferred.
[0029]
Density
The ethylene copolymer (A) according to the present
invention has a density d of 850 kg/m3 or more and 920 kg/m3 or
less (requirement (3)).
The density d of the ethylene copolymer (A) according to
the present invention is usually in the range of from 850 to 920
10 kg/m3
, preferably from 850 to 910 kg/m3
, more preferably from 855
to 910 kg/m3
, and still more preferably from 857 to 905 kg/m3
.
[0030]
The density d preferably satisfies the above range, because
a crosslinked product or a crosslinked foamed product excellent
15 in balance between the flexibility and strength is more likely
obtained.
[0031]
The density d as used in the present invention is a value
measured in accordance with ASTM Dl505 at a temperature of 23°C.
20 · MFR (melt flow rate)
It is preferred that MFR2 . 16 (the melt flow rate measured at
a load of 2.16 kg and at a temperature of 190°C) of the ethylene
copolymer (A) according to the present invention be within the
range of from 0.01 to 200 g/10 min, but not particularly limited
SF-2899
17
thereto (requirement (4)).
The value of MFR of the ethylene copolymer (A) according
to the present invention can be selected as appropriate depending
on the application, preferably within the above range. The MFR2 . 16
5 of the ethylene copolymer (A) according to the present invention
is preferably within the range of from 0.01 to 200 g/10 min, more
preferably from 0.1 to 100 g/10 min, still more preferably from
0.1 to 40 g/10 min, even more preferably from 0.1 to 25 g/10 min,
and particularly preferably from 0.1 to 10 g/10 min, but not
10 particularly limited thereto. Further, the MFR2 •16 of the ethylene
copolymer (A) is also preferably 2.0 or more. The larger the
molecular weight of the ethylene copolymer (A), the smaller the
value of MFR2 •16 • The method for controlling the molecular weight
will be described in the "Production of ethylene copolymer (A)"
15 section. It is preferred that the value of MFR2 . 16 be equal to or
lower than the above mentioned upper limit, from the viewpoint
that it improves the strength of the resulting molded article.
It is preferred that the value of MFR2 •16 be equal to or higher
than the above mentioned lower limit, from the viewpoint that it
20 improves the fluidity of the ethylene polymer (A) upon melt
molding.
[0032]
Mw/Mn
The ethylene copolymer (A) according to the present
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SF-2899
18
invention preferably has a molecular weight distribution (Mw/Mn),
which is calculated as the ratio of the weight-average molecular
weight Mw and the number average molecular weight Mn obtained by
gel permeation chromatography (GPC), of from 1. 5 to 3. 5, and more
5 preferably of from 1. 5 to 3. 0, but not particularly limited thereto.
The Mw/Mn can be controlled to be in the above mentioned range
by appropriately selecting the polymerization catalyst as
described in the section of "olefin polymerization catalyst".
The Mw/Mn within the above range is preferred from the viewpoint
10 that it improves the melt moldability and the strength of the
resulting molded article.
[0033]
Production of ethylene copolymer (A)
The ethylene copolymer (A) according to the present
15 invention can be any ethylene copolymer which satisfies the above
requirements (1), (2) and (3), and it can be suitably produced,
for example, by copolymerizing ethylene with at least one ex-olefin
having from 3 to 20 carbon atoms in the presence of an olefin
polymerization catalyst, but not particularly limited thereto.
20 Olefin polymerization catalyst
The ethylene copolymer (A) of the present invention has the
above described properties, and the production method thereof is
not particularly limited. The ethylene copolymer (A) can be
produced, for example, by copolymerizing ethylene with one or more
SF-2899
19
kinds selected from a-olefins having from 3 to 20 carbon atoms
in the presence of an olefin polymerization catalyst composed of
the following catalyst components [A] and [B].
[A] A crosslinked metallocene compound represented by the
5 following general formula [I]:
[0034]
[I J
(wherein in the formula [I], M represents a transition metal; p
represents a valence of a transition metal; X may be the same or
10 different and each represents a hydrogen atom, a halogen atom or
a hydrocarbon group; R1 and R2 may be the same or different ,from
each other and each represents a rr-electron conjugated ligand
coordinated to M, and Q represents a divalent group cross linking
two rr-electron conjugated ligands R1 and R2
).
15 [B] At least one kind of compound selected from (b-1) an
organoaluminum oxy compound (b-1), a compound (b-2) forming an
ion pair by reacting with the metallocene compound [A], and an
organoaluminum compound (b-3).
[0035]
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20
The copolymerization may be carried out, for example, by
solution polymerization of ethylene and one or more kinds of
monomers selected from o:-olefins in the presence of such an olefin
polymerization catalyst at a temperature range of from 0 to 200°C
5 under the coexistence of a solvent.
[0036]
However, the ethylene copolymer (A) according to the present
invention may be produced without any limitation on the production
method as long as the above mentioned properties are satisfied.
10 The ethylene copolymer (A) may be prepared, for example, by using
a metallocene compound having a structure different from the
formula [I] or a co-catalyst other than the catalyst component
[B] in the copolymerization, or by a technique of reactor blending,
physical blending or the like using well-known two or more kinds
15 of ethylene copolymers.
[0037]
Hereinafter, the above mentioned method for producing the
ethylene copolymer (A) will further be described in which ethylene
and one or more kinds selected from o:-olefins having 3 to 20 carbon
20 atoms are copolymerized in the presence of an olefin
polymerization catalyst containing the catalyst components [A]
and [B].
[0038]
Catalyst component [A]
SF-2899
21
The catalyst component [A] is a crosslinked metallocene
compound represented by the formula [I]. In the Formula [I],
examples of the transition metal represented by M include Zr, Ti,
Hf, V, Nb, Ta and Cr; and preferred transition metal is Zr, Ti
5 or Hf, and more preferred transition metal is Zr or Hf.
[0039]
In the general formula [I], examples of then-electron
conjugated ligand represented by R1 and R2 include a ligand having
an ll-cyclopentadienyl structure, an ll-benzene structure, an
10 ll-cycloheptatrienyl structure and an ll-cyclooctatetraene
structure. A ligand having an ll-cyclopentadienyl structure is
particularly preferred. Examples of the ligand having an
ll-cyclopentadienyl structure include cyclopentadienyl group,
indenyl group, hydrogenated indenyl group, fluorenyl group and
15 the like. These groups may be further substituted with a halogen
atom; a hydrocarbon group such as alkyl group, aryl group, aralkyl
group, alkoxy group and aryloxy group; a hydrocarbon
group-containing silyl group such as a trialkyl silyl group; a
chain or cyclic alkylene group; and the like.
20 [0040]
In the general formula [I], a group crosslinking R1 and R2
represented by Q is not particularly limited as long as it is a
divalent group. Examples thereof include linear or branched
alkylene groups, unsubstituted or substituted cycloalkylene
SF-2899
22
groups, alkylidene groups, unsubstituted or substituted
cycloalkylidene groups, unsubstituted or substituted phenylene
groups, silylene group, dialkyl-substituted silylene groups,
germyl group, dialkyl-substituted germyl groups, and the like.
5 [0041]
The catalyst component [A] may be specifically exemplified
by the metallocene complexes used in Examples described later,
but is not limited to these compounds.
[0042]
10 Such a catalyst component [A] is preferably used as an olefin
polymerization catalyst together with a catalyst component [B].
[0043]
Catalyst component [B]
When the catalyst component [A] is used as a component of
15 an olefin polymerization catalyst for producing the ethylene
copolymer (A) , the olefin polymerization catalyst prefer,ably
contains a catalyst component [B] constituted of at least one kind
of compound selected from an organoaluminum oxy compound (b-1),
a compound (b-2) ·forming an ion pair by reacting with the catalyst
20 component [A] and an organoaluminum compound (b-3) . Here, the
catalyst component [B] is preferably used in any of the following
embodiments [ell to [c4] from the viewpoint of polymerization
activity and the properties of the resulting olefin polymer:
[cl] an organoaluminum oxy compound (b-1) only,
SF-2899
23
[c2] an organoaluminum oxy compound (b-1) and an organoaluminum
compound (b-3) ,
[c3] a compound (b-2) forming an ion pair by reacting with the
catalyst component [A] and an organoaluminum compound (b-3), and
5 [c4] an organoaluminum oxy compound (b-1) and a compound (b-2)
forming an ion pair by reacting with the catalyst component [A] .
[0044]
However, when a metallocene compound in which Q in the
general formula [I] is a silylene group is used as the catalyst
ii 10 component [A] , a compound (b-2) forming an ion pair by reacting
('·I
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\!
with the catalyst component [A] is not used as the component [B],
and only [c1] and [c2] in the above [cl] to [c4] are used as the
preferred component [B] .
[0045]
15 Hereinafter, respective components capable of constituting
the catalyst component [B] will be specifically described ..
Organoaluminum oxy compound (b-1)
As the organoaluminum oxy compound (b-1), a conventionally
known aluminoxane may be used as it is. Specifically, there may
20 be mentioned a compound represented by the following general
formulae [II] and/or [III]:
[0046]
SF-2899
24
R+AIJ -Ot:-AIR2 n
R ··· [II]
'---+-( Al-0+-) __. I n
R ··· [TII]
There may be mentioned a compound represented by the general
formula [II] or [III] (wherein in the formula [II] or [III], R
represents a hydrocarbon group having 1 to 10 carbon atoms and
5 n represents an integer of two or more), and particularly a
methylaluminoxane in which R is a methyl group and n is a number
of 3 or more and preferably 10 or more is used. (Hereinafter,
an organoaluminum oxy compound in which R is a methyl group in
the general formula [II] or [III] may be referred to as a
10 "methylaluminoxane".)
Further, as the organoaluminum oxy compound (b-1), a
methylaluminoxane analogue which is soluble in a saturated
hydrocarbon is also preferably used, and a modified
methylaluminoxane represented by the following general formula
,, 15 [IV] may be mentioned, for example:
q
[0047]
SF-2899
25
-f--AI-0-+-) --+-( Al-Ot--
1 n I m
Me R ... [IV]
(wherein in the formula [IV], R represents a hydrocarbon group
having 2 to 20 carbon atoms, and m and n represent an integer of
two or more. )
5 The modified methylaluminoxane represented by the general
formula [IV] is prepared using trimethylaluminum and
alkylaluminum other than the trimethylaluminum (for example, the
production method is disclosed in US 4960878, US 5041584 and the
like) and is commercially produced under the trade name of MMAO
10 and TMAO in which R is an isobutyl group, which is prepared using
trimethylaluminum and triisobutylaluminum by a manufacturer such
as Toso Finechem Corporation and the like (for example, see "Toso
Research and Technology Report" Vo1.47, 55 (2003)).
[0048]
15 Further, as the organoaluminum oxy compound (b-1), an
organoaluminum oxy compound insoluble in benzene may also be used,
which is mentioned in Japanese Laid-Open Patent Publication No.
H02-78687, and an organoaluminum oxy compound containing boron
represented by the following general formula [V] may also be used:
20 [0049]
SF-2899
26
Rd Rl c Rd "A I-O-B-0-AI /
Rd / ""R d ··· [V]
(wherein in the formula [V], Rc represents a hydrocarbon group
having 1 to 10 carbon atoms. Rct may be the same or different from
each other and represents a hydrogen atom, a halogen atom or a
5 hydrocarbon group having from 1 to 10 carbon atoms.)
Further, the above described organoaluminum oxy compound
(b-1) may contain a slight amount of an organoaluminum compound.
Compound (b-2) forming an ion pair by reacting with catalyst
component [A]
10 As the compound (b-2) forming an ion pair by reacting with
the catalyst component [A] (hereinafter, may be abbreviated as
an "ionic compound (b-2) ") , there may be mentioned a Lewis acid,
an ionic compound, a borane compound, a carborane compound and
the like, which are described in Japanese Laid-Open Patent
15 Publication No. HOl-501950, Japanese Laid-Open Patent
Publication No. HOl-502036, Japanese Laid-Open Patent
Publication No. H03-179005, Japanese Laid-Open Patent
Publication No. H03-179006, Japanese Laid-Open Patent
Publication No. H03-207703, Japanese Laid-Open Patent
20 Publication No. H03-207704, USP5321106 and the like. Further,
as the ionic compound (b-2) , there may be mentioned a heteropoly
SF-2899
27
compound and an isopoly compound.
[0050]
In the present invention, an ionic compound (b-2) which is
preferably used is a compound represented by the following general
5 formula [VI]:
[0051]
wherein in the formula [VI], examples of Re+ include H+, a carbenium
cation, an oxonium cation, an ammonium cation, a phosphonium
10 cation, a cycloheptyltrienyl cation, a ferrocenium cation having
a transition metal and the like. Rf to Ri may be the same or
different from each other, and is an organic group, and preferably
an aryl group.
[0052]
15 Specific examples of the carbenium cation include
trisubstituted carbenium cations such as triphenylcarbenium
cation, tris(methylphenyl)carbenium cation,
tris(dimethylphenyl)carbenium cation and the like.
[0053]
20 Specific examples of the ammonium cation include
trialkylammonium cations such as trimethylammonium cation,
SF-2899
28
triethylammonium cation, tri(n-propyl)ammonium cation,
triisopropylammonium cation, tri (n-butyl) ammonium cation, and
triisobutylammonium cation; N,N- dialkylanilinium cations such
as N,N-dimethylanilinium cation, N,N-diethylanilinium cation,
5 and N,N-2,4,6-pentamethylanilinium cation; dialkylammonium
cations such as diisopropylammonium cation and
dicyclohexylammonium cation; and the like.
[0054]
Specific examples of the phosphonium cation include
10 triarylphosphonium cations such as triphenylphosphonium cation,
tris(methylphenyl)phosphonium cation, and
tris(dimethylphenyl)phosphonium cation; and the like.
[0055]
Among those mentioned above, Re+ is preferably a carbenium
15 cation, an ammonium cation and the like and particularly
preferably a triphenylcarbenium cation, anN, N-dimethylanilinium
cation and an N,N-diethylanilinium cation.
[0056]
Specific examples of the ionic compound (b-2) which is a
20 carbenium salt include triphenylcarbenium tetraphenylborate,
triphenylcarbenium tetrakis(pentafluorophenyl)borate,
triphenylcarbenium
tetrakis(3,5-ditrifluoromethylphenyl)borate,
tris(4-methylphenyl)carbenium
SF-2899
29
tetrakis(pentafluorophenyl)borate,
tris(3,5-dimethylphenyl)carbenium
tetrakis(pentafluorophenyl)borate and the like.
I [0057]
I 5 Examples of the ionic compound (b-2) which is an ammonium
salt include a trialkyl-substituted ammonium salt, an
N,N-dialkylanilinium salt, a dialkylammonium salt and the like.
[0058]
Specific examples of the ionic compound (b-2) which is a
10 trialkyl-substituted ammonium salt include triethylammonium
tetraphenyl borate, tripropylammonium tetraphenyl borate,
tri(n-butyl)ammonium tetraphenyl borate, trimethylammonium
tetrakis(p-tolyl)borate, trimethylammonium
tetrakis(o-tolyl)borate, tri(n-butyl)ammonium
15 tetrakis(pentafluorophenyl)borate, triethylammonium
tetrakis(pentafluorophenyl)borate, tripropylammonium
tetrakis(pentafluorophenyl)borate, tripropylammonium
tetrakis(2,4-dimethylphenyl)borate, tri(n-butyl)ammonium
[J tetrakis (3, 5-dimethylphenyl) borate, tri (n-butyl) ammonium
H
~~
ti
11 20 tetrakis ( 4-trifluoromethylphenyl) borate, tri (n-butyl) ammonium
tetrakis(3,5-ditrifluoromethylphenyl)borate,
tri(n-butyl)ammonium tetrakis(o-tolyl)borate,
dioctadecylmethylammonium tetraphenylborate,
dioctadecylmethylammonium tetrakis(p-tolyl)borate,
;.,
~i
~:1
,'I,
""
~~
{.!
SF-2899
30
dioctadecylmethylammonium tetrakis(o-tolyl)borate,
dioctadecylmethylammonium tetrakis(pentafluorophenyl)borate,
dioctadecylmethylammonium tetrakis(2,4-dimethylphenyl)borate,
dioctadecylmethylammonium tetrakis(3,5-dimethylphenyl)borate,
5 dioctadecylmethylammonium
tetrakis(4-trifluoromethylphenyl)borate,
dioctadecylmethylammonium
tetrakis(3,5-ditrifluoromethylphenyl)borate,
dioctadecylmethylammonium and the like.
Specific examples of the ionic compound (b-2) which an
N, N-dialkyl anilinium salt include N, N-dimethylanilinium
tetraphenylborate, N,N-dimethylanilinium
tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium
15 tetrakis(3,5-ditrifluoromethylphenyl)borate,
N,N-diethylanilinium tetraphenylborate, N,N-diethylanilinium
tetrakis(pentafluorophenyl)borate, N,N-diethylanilinium
tetrakis(3,5-ditrifluoromethylphenyl)borate,
N,N-2,4,6-pentamethylanilinium tetraphenylborate,
20 N,N-2,4,6-pentamethylanilinium
tetrakis(pentafluorophenyl)borate and the like.
[ 0 0 60 l
Specific examples of the dialkyl ammonium salt include
di(l-propyl)ammonium tetrakis(pentafluorophenyl)borate,
SF-2899
31
dicyc1ohexy1ammonium tetraphenylborate and the like.
[0061]
As other ionic compounds (b-2) , the ionic compounds
disclosed by the present applicant (Japanese Laid-Open Patent
5 Publication No. 2004-51676) can be used without any restriction.
[0062]
The above mentioned ionic compounds (b-2) may be used alone
or as a mixture of two or more kinds thereof.
Organoaluminum compound (b-3)
10 Examples of the organoaluminum compound (b-3) include an
organoaluminum compound represented by the following general
formula [VII] , an alkylated complex of a metal of Group 1 of the
Periodic Table and aluminum, which is represented by the following
formula [VIII], and the like.
15 [0063]
[VII]
(wherein in the formula [VII] , Ra and Rb may be the same or different
from each other and each represents a hydrocarbon group having
from 1 to 15 carbon atoms and preferably from 1 to 4 carbon atoms;
20 X represents a halogen atom; and m, n, p, and q are numbers
satisfying the conditions: 0 < m ~ 3, 0 ~ n < 3, 0 ~ p < 3, 0 ~
q < 3, and m + n + p + q = 3) •
Specific examples of the organoaluminum compound
represented by the formula [VII] include tri-n-alkylaluminums
SF-2899
32
such as trimethylaluminum, triethylaluminum,
tri-n-butylaluminum, trihexylaluminum, and trioctylaluminum;
tri-branched-chain alkylaluminums such as tri-isopropylaluminum,
tri-isobutylaluminum, tri-sec-butylaluminum,
5 tri-tert-butylaluminum, tri-2-methylbutyl aluminum,
tri-3-methyl hexyl aluminum, and tri-2-ethylhexylaluminum;
tri-cycloalkylaluminums such as tri-cyclohexylaluminum, and
tri-cyclooctylaluminum; such as
triphenylaluminum and
triarylaluminums
tritolylaluminum;
diisopropylaluminum
dialkylaluminum
10 hydrides such as hydride and
diisobutylaluminum
isoprenylaluminum
hydride;
represented
alkenylaluminums
by the general
such as
formula:
(i-C4H9lxAly(CsHlolz (wherein, x, y and z are positive integers, and
z is a number satisfying the condition: z ~ 2x) and the like;
15 alkylaluminum alkoxides such as isobutylaluminum methoxide and
isobutylaluminum ethoxide; dialkylaluminum alkoxides sucp as
dimethylaluminum methoxide, diethylaluminum ethoxide, and
dibutylaluminumbutoxide; alkylaluminum sesquialkoxides such as
ethylaluminum sesquiethoxide and butylaluminum sesquibutoxide;
20 partially alkoxylated alkylaluminums having an average
composition represented by the general formula Ra2 . 5Al (ORb) 0 . 5 and
the like; alkylaluminum aryloxides such as diethylaluminum
phenoxide,
diethylaluminum(2,6-di-t-butyl-4-methylphenoxide);
and
SF-2899
33
dialkylaluminum halides such as dimethylaluminum chloride,
diethylaluminum chloride, dibutylaluminum chloride,
diethylaluminum bromide, and diisobutylaluminum chloride;
alkylaluminum sesquihalides such as ethylaluminum sesquichloride,
5 butylaluminum sesquichloride, and ethylaluminum sesquibromide;
partially halogenated alkylaluminums, for example, alkylaluminum
dihalides such as ethylaluminum dichloride; dialkylaluminum
hydrides such as diethylaluminum hydride and dibutylaluminum
hydride; other partially hydrogenated alkylaluminums, for
10 example, alkylaluminum dihydrides such as ethylaluminum
dihydride and propylaluminum dihydride; partially alkoxylated
and halogenated alkylaluminums such as ethylaluminum
ethoxychloride, butylaluminum butoxychloride and ethylaluminum
ethoxybromide; and the like.
15 [0064]
An alkylated complex of a metal of Group 1 of the E'eriodic
Table and aluminum, represented by the formula [VIII] (wherein
in the formula [VIII], M2 represents Li, Na, or K, and Ra represents
20 a hydrocarbon group having from 1 to 15 carbon atoms and preferably
:I
from 1 to 4 carbon atoms). Examples of such compounds include
[0065]
In addition, a compound similar to the compound represented
:I
SF-2899
34
by the formula [VII] can also be used. Examples thereof include
an organoaluminum compound in which two or more aluminum compounds
are bonded via a nitrogen atom. Specific examples of such a
compound include (C2H5 ) 2AlN (C2H5 ) Al (C2H5 ) 2 and the like.
5 [0066]
i,l,
As the organoaluminum compound (b-3) , trimethylaluminum and
tri-isobutyl aluminum are preferably used, from the viewpoint of
easy availability.
Production of ethylene copolymer (A)
10 The ethylene copolymer (A) according to the present
invention may be suitably produced by copolymerizing ethylene with
at least one kind of a-olefin having 3 to 20 carbon atoms in the
presence of the above mentioned olefin polymerization catalyst.
The copolymerization can be carried out, for example, by
15 performing solution polymerization in the presence of a sol vent.
Here, the polymerization temperature is 140°C or higher, for
example, and preferably 150°C or higher, but not particularly
limited thereto. It is preferred that the polymerization
reaction be carried out at a temperature as mentioned above,
20 because the value of the ratio MFR10 /MFR2 . 16 and the vinyl group
content of the obtained ethylene copolymer (A) can be increased.
[0067]
When carrying out the polymerization, the method for using
each of the components and the sequence of addition are selected
SF-2899
35
arbitrarily. For example, a method in which the catalyst
component (A) and the catalyst component (B) are added to a
polymerization vessel in an arbitrary order may be mentioned.
In the above mentioned method, two or more of the respective
5 catalyst components may be brought into contact in advance.
[0068]
When the ethylene copolymer (A) of the present invention
is produced by copolymerization of ethylene and at least one kind
of ex-olefin having 3 to 2 0 carbon atoms using the olefin
10 polymerization catalyst as mentioned above, the catalyst
component [A] is used usually in an amount of from 10-9 to 10-1
mol, preferably from 10-8 to 10-2 mol per liter of reaction volume.
[0069]
The component (b-1) is used in an amount such that the molar
15 ratio [(b-1)/M] of the component (b-1) to the total transition
metal atoms (M) in the component (A) is usually from 1 to 10,,000,
and preferably from 10 to 5,000. The component (b-2) is,used in
an amount such that the molar ratio [(b-2)/M] of the component
(b-2) to the total transition metal atoms (M) in the component
20 (A) is usually from 0. 5 to 50, and preferably from 1 to 20. The
component (b-3) is used in an amount usually from 0 to 5 mmol and
preferably approximately from 0 to 2 mmol per liter of
polymerization volume.
[0070]
SF-2899
36
Here, the feeding molar ratio of ethylene to an a-olefin
having 3 to 20 carbon atoms may be selected as appropriate
depending on the properties of the intended ethylene copolymer
(A). The feeding molar ratio of ethylene: a-olefin is usually
5 from 10:90 to 99.9:0.1, preferably from 30:70 to 99.9:0.1, and
more preferably from 50:50 to 95.0:5. 0, but not particularly
limited thereto.
[0071]
Examples of the a-olefin having from 3 to 20 carbon atoms
10 include linear or branched a-olefins, such as propylene, 1-butene,
2-butene, 1-pentene, 3-methyl-1-butene, 1-hexene,
4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene, and
1-dodecene. Among these a-olefins, 1-butene, 1-hexene,
4-methyl-1-pentene and 1-octene are particularly preferably used.
15 Among these, an a-olefin having 3 to 10 carbon atoms is more
preferably used in the present invention.
[0072]
The "solution polymerization", which is preferably employed
for the production of the ethylene copolymer (A), is a general
20 term used to refer to a method in which polymerization is carried
out in a state where a polymer is dissolved in a hydrocarbon sol vent
that is inert to the copolymerization reaction. In the solution
polymerization according to the present invention, the
polymerization temperature is usually in the range of from 0 to
f ~
fi
'i
li
[!
SF-2899
37
2DD°C, preferably 14D°C or higher, and more preferably 15D°C or
higher.
[DD73]
In the solution polymerization according to the present
5 invention, the polymerization temperature of less than D°C is
impractical in terms of productivity, because the polymerization
activity is extremely reduced. Further, there are cases where
the vinyl group content of the ethylene copolymer (A) is decreased.
If the polymerization temperature is within the range of from D°C
10 or higher, as the temperature increases, the solution viscosity
during the polymerization is decreased, the removal of the
polymerization heat becomes easier, and the vinyl group content
of the ethylene copolymer (A) is increased. However, if the
polymerization temperature is greater than 2DD°C, the
15 polymerization activity may be extremely reduced. It is
preferred that the polymerization of the ethylene copolymer (A)
according to the present invention be carried out at a relatively
high temperature of 14D°C or higher, preferably 15D°C or higher,
since the ethylene copolymer (A) has a relatively high ratio
20 MFR10/MFR2 . 16 and a relatively high vinyl group content.
[DD74]
The polymerization pressure is usually from normal pressure
to lD MPa gauge pressure, preferably from normal pressure to 8
MPa gauge pressure, and the polymerization reaction may be carried
SF-2899
38
out in any of batch, semi-continuous and continuous processes.
The reaction time (average residence time, if the copolymerization
reaction is carried out by a continuous process) varies depending
on the conditions such as the catalyst concentration and
5 polymerization temperature, and it may be selected as appropriate.
It is usually from one minute to 3 hours and preferably from 10
minutes to 2. 5 hours. Further, the polymerization may be carried
out in two or more stages which have different reaction conditions.
The molecular weight of the resulting ethylene copolymer (A) can
10 be controlled by changing the hydrogen concentration or the
polymerization temperature in the polymerization system, and also
by changing the amount of the catalyst component (B) to be used.
When hydrogen is added to the polymerization system, an
appropriate amount to be added is approximately from 0. 001 to 5, 000
15 NL per 1 kg of the ethylene copolymer to be produced. In addition,
the vinyl-group content of the resulting ethylene copolymer (A)
can be increased by increasing the polymerization temperature and
by significantly reducing the amount of hydrogen added. Further,
the ratio MFR10 /MFR2 . 16 of the resulting ethylene copolymer (A)
20 serves as an index showing that the larger the value of the ratio,
":-!
'i
the more long chain branched structure contained in the polymer.
However, in the case of coordination polymerization as shown in
the Examples described later, it is considered that the long chain
branched structure in the ethylene copolymer (A) is produced by
SF-2899
39
reinsertion of a molecular chain (macromonomer) having a terminal
vinyl group generated by the ~-dehydrogenation reaction. For
this reason, the value of the ratio MFR10IMFR2 . 16 of the ethylene
copolymer (A) can be controlled by increasing or decreasing the
5 ratio of the macromonomer concentration to the ethylene
concentration ( [macromonomer] I [ethylene]) in the solution. In
general, if the ratio [macromonomer] I [ethylene] is high, the
amount of long-chain branching in the ethylene polymer is
increased, and if the ratio [macromonomer] I [ethylene] is low,
10 the amount of long-chain branching in the ethylene polymer is
decreased. Examples of the technique for increasing or
decreasing the ratio [macromonomer] I [ethylene] in the solution
include the following [1] to [4].
[0075]
15 [1] Polymerization temperature
The higher the polymerization temperature is, the .more
likely the ~-dehydrogenation reaction occurs. Therefore., if the
polymerization temperature is increased, the ratio
[macromonomer] I [ethylene] is increased, resulting in an increase
20 in the amount of long chain branching in the ethylene copolymer.
[2] Polymer concentration
If the polymer concentration in the solution is increased,
the macromonomer concentration is relatively increased, which
leads to an increase in the ratio [macromonomer] I [ethylene],
SF-2899
40
resulting in an increase in the amount of long chain branching
in the ethylene copolymer.
[3] Ethylene conversion rate
If the ethylene conversion rate is increased, the ethylene
5 concentration in the solution is decreased, which leads to an
increase in the ratio [macromonomer] I [ethylene], resulting in
an increase in the amount of long chain branching in the ethylene
copolymer.
[4] Solvent species
10 If a solvent having a low boiling point is used as the
polymerization solvent, the ethylene concentration in the
solution is decreased, which leads to an increase in the ratio
[macromonomer] I [ethylene], resulting in an increase in the
amount of long chain branching in the ethylene copolymer.
15 [0076]
In addition to controlling the ~-dehydrogenation reaction,
the chain transfer reaction to Al and the like can also be
controlled to increase and decrease the ratio [macromonomer] I
[ethylene]), thereby changing the amount of long chain branching
20 in the ethylene polymer.
[0077]
The solvent used in the solution polymerization is usually
an inert hydrocarbon solvent and preferably a saturated
hydrocarbon solvent having a boiling point of from 50 to 200°C
SF-2899
41
under normal pressure. Specific examples of the sol vent include
aliphatic hydrocarbons such as pentane, hexane, heptane, octane,
decane, dodecane, and kerosene; and alicyclic hydrocarbons such
as cyclopentane, cyclohexane, and methylcyclopentane. Also
5 included in the category of the ftinert hydrocarbon solvents",
which relates to the high temperature solution polymerization of
the present invention, are aromatic hydrocarbons such as benzene,
toluene and xylene; and halogenated hydrocarbons such as ethylene
chloride, chlorobenzene, and dichloromethane; and the use thereof
10 is not restricted. As described above, in the high temperature
solution polymerization according to the present invention, not
only an organoaluminum oxy compound which is soluble in aromatic
hydrocarbons and which has been conventionally and frequently used,
but also a modified methylaluminoxane such as MMAO which is soluble
15 in aliphatic hydrocarbons and alicyclic hydrocarbons can be used.
As a result, by employing an aliphatic hydrocarbonor an alicyclic
hydrocarbon as a solvent for solution polymerization, the
possibility that the polymerization system or the resulting
ethylene polymer is contaminated with aromatic hydrocarbons can
II
20 be almost entirely eliminated. In other words, the high
temperature solution polymerization method according to the
present invention also has characteristics that it allows for
reducing the environmental burden and minimizing the impact on
human health.
SF-2899
42
[0078]
In order to prevent the variations in the physical
properties, it is preferred that the ethylene copolymer (A)
obtained by the polymerization reaction and optionally added other
5 components be melted, kneaded, and granulated in an arbitrary
manner.
Graft modification
A part or the whole of the ethylene copolymer (A) of the
present invention may be graft modified with a polar monomer before
10 use.
[0079]
Examples of the polar monomer include hydroxyl
group-containing ethylenically unsaturated compounds, amino
group-containing ethylenically unsaturated compounds, epoxy
15 group-containing ethylenically unsaturated compounds, aromatic
vinyl compounds, unsaturated carboxylic acids and derivat,ives
/:
~~
~-;
1:
thereof, vinyl ester compounds, vinyl chloride, carbodiimide
I'
~ i
compounds, and the like.
i!
:-J
~I
'I
'I
[0080]
lj
,·i 20
1: )i
As the polar monomer, an unsaturated carboxylic acid or a
[: derivative thereof is particularly preferred. Examples of the
::;
!i !i 'I
unsaturated carboxylic acid or derivative thereof include
I
I
unsaturated compounds having one or more carboxylic groups; esters
of compounds having a carboxylic acid group and an alkyl alcohol;
SF-2899
43
unsaturated compounds having one or more carboxylic anhydride
groups, and the like. Examples of unsaturated groups include
vinyl group, vinylene group, unsaturated cyclic hydrocarbon
groups and the like.
5 [0081]
Specific examples of compounds include unsaturated
carboxylic acids such as acrylic acid, maleic acid, fumaric acid,
tetrahydrophthalic acid, itaconic acid, citraconic acid,
crotonic acid, isocrotonic acid, and nadic acid (trade mark)
10 (endo-cis-bicyclo[2.2.l]hept-5-ene-2,3-dicarboxylic acid); or
derivatives thereof such as acid halides, amides, imides,
anhydrides, esters and the like. Specific examples of the
derivative include malenyl chloride, maleimide, maleic anhydride,
citraconic anhydride, monomethyl maleate, dimethyl maleate,
15 glycidyl maleate and the like.
[0082]
These unsaturated carboxylic acids and/or derivatives
thereof may be used alone or in combination with two or more kinds.
Among these, an unsaturated dicarboxylic acid or an acid anhydride
20 thereof is suitable. Particularly, maleic acid, nadic acid or
an acid anhydride thereof is preferably used.
[0083]
Modification is achieved by graft polymerizing a polar
monomer to a product to be modified. In the graft polymerization
SF-2899
44
of such a polar monomer to the product to be modified, the polar
monomer is used usually in an amount of from 1 to 100 parts by
mass and preferably from 5 to 80 parts by mass based on 100 parts
by mass of the product to be modified. This graft polymerization
5 is usually performed in the presence of a radical generator.
[0084]
As the radical generator, for example, the same radical
generators as those mentioned in the radical generator (c)
described later can be used.
10 [0085]
The radical generator may be used, mixed with the product
to be modified and the polar monomer as it is, but it may be
disso1 ved in a small amount of an organic sol vent before use. As
the organic solvent, any organic solvent can be used without
15 particular limitation, as long as it is an organic solvent capable
of dissolving the radical generator.
I !·:,
[0086]
:!
ii In the graft polymerization of a polar monomer to the product
I11
to be modified, a reducing substance may be used. If a reducing
fl 20
'I
substance is used, the grafted amount of the polar monomer can
" 'I be increased. The graft modification of the product to be
,,
'i
modified with a polar monomer can be performed by a conventionally
known method.
[0087]
!I :'I
'I
SF-2899
45
The modified amount (the grafted amount of the polar
monomer) of the modified product thus obtained is usually in the
range of from 0.1 to 50% by mass, preferably from 0.2 to 30% by
mass and more preferably from 0.2 to 10% by mass, based on 100%
5 by mass of the modified product.
[0088]
When the ethylene copolymer (A) of the present invention
is used after graft modifying a part or the whole thereof with
a polar monomer, the resulting copolymer has an excellent
10 adhesiveness to other resins and excellent compatibility, and the
wettability of the surface of the resulting molded article may
be improved.
[0089]
Further, if the content of the polar monomer such as an
:!
15 unsaturated carboxylic acid and/or a derivative thereof is within
the above range, when the ethylene copolymer (A) of the pre,sent
invention is used after graft modifying a part of or the whole
thereof, the resulting copolymer has a high adhesive strength to
a polar group-containing resin (such as polyester, polyvinyl
20 alcohol, ethylene-vinyl alcohol copolymer, polyamide, PMMA,
polycarbonate and the like).
[0090]
,,
In addition, other polymers such as a thermoplastic resin
or an elastomer can be blended to a graft-modified ethylene
SF-2899
46
copolymer (A) obtained by graft modifying a part or the whole of
the ethylene copolymer (A) of the present invention, to the extent
that the properties of the modified product are not impaired.
They may be blended during the graft-modifying stage or after the
5 modification.
[0091]
Other resin component (B)
The crosslinked product or the crosslinked foamed product
of the present invention is formed from the above mentioned
10 ethylene copolymer (A) or a resin composition containing the
ethylene copolymer (A) . The crosslinked product or the
crosslinked foamed product is not particularly limited as long
as it contains the ethylene copolymer (A) as an essential component,
and it may be formed from a resin composition containing other
15 resin component (B) other than the ethylene copolymer (A) .
20
Examples of the other resin component (B) include ex-olefin-polar
monomer copolymers, ethylene-cx-olefin-non-conj ugated polyene
copolymers and various types of olefinic polymers.
[0092]
When the crosslinked product or the crosslinked foamed
product of the present invention contains the other resin
component (B) other than the ethylene copolymer (A), the other
resin component (B) is preferably an ethylene-polar monomer
copolymer (Bl).
SF-2899
47
[0093]
Examples of the polar monomer of the ethylene-polar monomer
copolymer (Bl) include unsaturated carboxylic acids and salts
thereof, esters thereof, ami des thereof, vinyl esters and carbon
5 monoxide. More specific examples thereof include unsaturated
carboxylic acids such as acrylic acid, methacrylic acid, fumaric
acid, itaconic acid, monomethyl maleate, monoethyl maleate,
maleic anhydride and itaconic anhydride; salts of these
unsaturated carboxylic acids, that is, salts of monovalent metals
10 such as lithium, sodium, and potassium and salts of polyvalent
metals such as magnesium, calcium, and zinc; unsaturated
carboxylic acid esters such as methyl acrylate, ethyl acrylate,
isopropyl acrylate, isobutyl acrylate, n-butyl acrylate,
isooctyl acrylate, methyl methacrylate, ethyl methacrylate,
15 isobutyl methacrylate, and dimethyl maleate; vinyl esters such
as vinyl acetate and vinyl propionate; carbon mon()xide; sulfur
dioxide; and the like. One or two or more of the above can be
used.
20
[0094]
More specifically, representative examples of the
ethylene-polar monomer copolymer (Bl) include
ethylene-unsaturated carboxylic acid copolymers such as
ethylene-acrylic acid copolymer and ethylene-methacrylic acid
copolymer; ionomers in which a part or the whole of the carboxyl
SF-2899
48
group of the above ethylene-unsaturated carboxylic acid copolymer
is neutralized by the above metal; ethylene-unsaturated
carboxylic acid ester copolymers such as ethylene-methyl acrylate
copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl
5 methacrylate copolymer, ethylene-isobutyl acrylate copolymer and
ethylene-n-butyl acrylate copolymer; ethylene-unsaturated
carboxylic acid ester-unsaturated carboxylic acid copolymers
such as ethylene-isobutyl acrylate-methacrylic acid copolymer
and ethylene-n-butyl acrylate-methacrylic acid copolymer; and
10 ionomers thereof in which a part or the whole of the carboxyl group
is neutralized by the above metal; and ethylene-vinyl ester
copolymers such as ethylene-vinyl acetate copolymer; and the like.
[0095]
Among these, particularly a copolymer of ethylene and a
15 polar monomer selected from unsaturated carboxylic acids, salts
thereof, esters thereof, and vinyl acetate is preferred. In
~: particular, an ethylene- (meth) acrylic acid copolymer or an
ionomer thereof, an ethylene-(meth)acrylic acid-(meth)acrylate
ester copolymer or an ionomer thereof, or an ethylene-vinyl
20 acetate copolymer is preferred, and an ethylene-vinyl acetate
copolymer is most preferred.

CLAIMS
1. A method for producing a crosslinked product, comprising
the steps of: melt molding an ethylene copolymer (A) or a
5 resin composition containing the ethylene copolymer (A); and
carrying out crosslinking;
wherein the ethylene copolymer (A) contains a
constitutional unit derived from ethylene and a constitutional
unit derived from an a-olefin having from 3 to 20 carbon atoms,
10 and satisfies all of the following requirements ( 1) , ( 2) and ( 3) :
~! (1) a vinyl group content per 1,000 carbon atoms as measured by
1H-NMR is 0.06 or more and one or less;
(2) a ratio MFR10/MFR2 . 16 is 8.5 or more and 50 or less; and
(3) a density d is 850 kg/m3 or more and 920 kg/m3 or less
15 (wherein, MFR10 represents a melt flow rate (g/10 min) as measured
in accordance with ASTM 01238 at a load of 10 kg and at a temperature
of 190"C; and MFR2 .16 represents a melt flow rate (g/10 min) as
measured in accordance with ASTM 01238 at a load of 2.16 kg and
at a temperature of 190"C).
20
2. The method for producing a crosslinked product according
to claim 1, wherein the ethylene copolymer (A) further satisfies
the following requirement (4):
(4) MFR2 •16 is within the range of from 0.01 to 200 g/10 min.
SF-2899
107
3. The method for producing a crosslinked product according
to claim 1 or 2, wherein the ethylene copolymer (A) is an ethylene
copolymer (Al) obtained by using ethylene and a-olefin alone as
5 monomers.
10
15
4. The method for producing a crosslinked product according
to any one of claims 1 to 3, further comprising the step of carrying
out foaming.
5. The method for producing a crosslinked product according
to any one of claims 1 to 3, wherein the step of melt molding is
carried out by injection molding or transfer molding, and wherein
the method further comprises the step of carrying out foaming.
6. A crosslinked product obtained by the method for producing
a crosslinked product according to any one of claims 1 to 5.
7. A laminated molded article comprising a layer composed of
20 one or more kinds of raw materials selected from the group
consisting of polyolefin, polyurethane, rubber, leather and
artificial leather, and the crosslinked product according to claim
6, wherein the layer composed of one or more kinds of raw materials
and the crosslinked product are laminated together.
SF-2899
108
8. The laminated molded article according to claim 7, wherein
the laminated molded article is a footwear part.
5 9. The laminated molded article according to claim 8, wherein
the footwear part is a midsole, an inner sole, or a sole.
t-,
li
"
10. An ethylene copolymer (A) which contains a constitutional
unit derived from ethylene and a constitutional unit derived from
10 an ex-olefin having from 3 to 20 carbon atoms, and which satisfies
all of the following requirements ( 1) , ( 2) and ( 3) :
(1) a vinyl group content per 1,000 carbon atoms as measured by
1H-NMR is 0.06 or more and one or less;
(2) a ratio MFR10 /MFR2 . 16 is 8. 5 or more and 50 or less; and
15 (3) a density d is 850 kg/m3 or more and 920 kg/m3 or less
(wherein, MFR10 represents a melt flow rate (g/10 min) as measyred
in accordance with ASTM D1238 at a load of 10 kg and at a temperature
i'
of 190°C; and MFR2 •16 represents a melt flow rate (g/10 min) as
(.·'
~ measured in accordance with ASTM 01238 at a load of 2.16 kg and
~-I
H
!I 20 at a temperature of l90°C).
!·i
i!
li
!'
11. The ethylene copolymer (A) according to claim 10, wherein
the ethylene copolymer (A) further satisfies the following
requirement (4):
SF-2899
109
(4) MFR2 . 16 is within the range of from 0.01 to 200 g/10 min.
12. The ethylene copolymer (A) according to claim 10 or 11,
wherein the ethylene copolymer (A) is an ethylene copolymer (Al)
5 obtained by using ethylene and a-olefin alone as monomers.
10
13. An ethylene copolymer composition comprising the ethylene
copolymer (A) according to any one of claims 10 to 12 and a
crosslinking agent (C) .
14. The ethylene copolymer composition according to claim 13,
further comprising a foaming agent (D) .