TECHNICAL FIELD
[0001] The present invention relates to a rubber
composition, a crosslinked product and a foamed product
of the composition, a rubber molded product comprising
5 the composition, and uses thereof. More particularly,
the invention relates to a rubber composition capable of
inhibiting formation of a gel-like substance, a rubber
molded product which is formed from the composition and
is excellent in rigidity, compression set, shape memory
10 property, etc., a rubber composition, and a rubber molded
product which is obtained by the use of the composition
as a raw material, is inhibited from fogging and
tackiness and is excellent in mechanical strength and
heat aging resistance.
15
BACKGROUND ART
[0002] Ethylene/-olefin rubbers and ethylene/-
olefin/non-conjugated diene copolymer rubbers have no
unsaturated bond in the main chain, and therefore, they
20 are excellent in weathering resistance, heat resistance
and ozone resistance as compared with conjugated diene
type rubbers. Taking advantage of these properties,
rubber compositions containing such copolymer rubbers,
crosslinked products of the compositions and foamed
3
products of the compositions have been broadly used for
parts of automobile industry, industrial rubber articles,
electrically insulating materials, civil engineering and
construction materials, rubber articles such as
5 rubberized fabric, etc.
[0003] For example, a rubber composition for
injection molding sponge, which contains an ethylene/-
olefin/non-conjugated polyene copolymer rubber, a
crystalline polyolefin resin and a blowing agent, is
10 known (see, for example, patent document 1).
[0004] Further, a rubber composition containing
an ethylene/-olefin/non-conjugated polyene copolymer
rubber, a polyolefin resin and a blowing agent, and a
rubber foamed product obtained by crosslinking and
15 foaming a rubber composition containing an ethylene/-
olefin/non-conjugated polyene copolymer rubber and a
synthetic resin are also known (see, for example, patent
documents 2 and 3).
[0005] Molded products obtained from these
20 compositions and the above-mentioned rubber foamed
product are excellent in hardness, etc., but they are
insufficient in compatibility of the ethylene/-
olefin/non-conjugated polyene copolymer rubber with other
4
resins (polyolefin resin, synthetic resin, etc.), and
there is yet room for improvement.
[0006] Crosslinked rubbers comprising a copolymer
rubber composed of ethylene and an -olefin of 3 to 20
5 carbon atoms and/or a non-conjugated polyene have been
favorably applied to uses requiring environmental
resistance, such as weatherstrips and water hoses for
automobiles, in the past. In the compounding for such
rubbers, a large amount of a softener is generally used
10 together with a reinforcing agent and a filler. For
automobiles for which lengthening of life will be
required more and more in the future, weatherstrips and
water hoses capable of withstanding long-term use and
maintaining initial performance become necessary, and
15 therefore, crosslinked rubbers exhibiting more excellent
environmental resistance than before have been desired.
[0007] Such crosslinked rubbers, however, have
problems of fogging and tackiness caused by a lowmolecular
weight component of the softener. The
20 “fogging” is a phenomenon that when a crosslinked rubber
is used as an interior skin material of a weatherstrip,
an instrument panel or the like of an automobile, a door
glass, a front glass, etc. are fogged by the lowmolecular
weight component evaporated from such a part,
5
and the “tackiness” is a phenomenon that the lowmolecular
weight component blooms on the surface of an
interior skin material of a weatherstrip, an instrument
panel or the like of an automobile to cause tacky
5 surface.
[0008] For example, there is disclosed, in a
patent document 4, a rubber composition that has become
excellent in weathering resistance, heat resistance and
low-temperature flexibility by adding a softener
10 (copolymer of ethylene and an -olefin of 3 to 20 carbon
atoms) having a number-average molecular weight of 400 to
2000, a pour point of not higher than –25°C and a
viscosity index of not less than 120, but problems of
fogging and tackiness have not been solved yet.
15 Patent document 1: Japanese Patent Laid-Open
Publication No. 195227/1998
Patent document 2: Japanese Patent Laid-Open
Publication No. 256095/2002
Patent document 3: Japanese Patent Laid-Open
20 Publication No. 212328/2002
Patent document 4: Japanese Patent Laid-Open
Publication No. 11255/2001
DISCLOSURE OF THE INVENTION
6
PROBLEM TO BE SOLVED BY THE INVENTION
[0009] It is an object of the present invention
(1) to provide a rubber composition capable of inhibiting
formation of a gel-like substance by improving
5 compatibility of an ethylene/-olefin/non-conjugated
polyene copolymer with a polyolefin resin, and a molded
product which is formed from the composition and is
excellent in rigidity, compression set, shape memory
property, etc.
10 [0010] It is an object of the present invention
(2) to provide a rubber composition and a rubber molded
product which is obtained by the use of the composition
as a raw material, is inhibited from fogging and
tackiness and is excellent in mechanical strength and
15 heat aging resistance.
MEANS TO SOLVE THE PROBLEM
[0011] In order to solve the above problems, the
present inventors have earnestly studied, and they have
20 accomplished the present invention.
That is to say, the rubber composition of the
present invention is a rubber composition comprising an
ethylene/-olefin/non-conjugated polyene copolymer (A),
7
and a polyolefin resin (B) and/or an ethylene/C3-C20 -
olefin copolymer (C), wherein
(1) a maximum value Pmax and a minimum value Pmin of
an ethylene distribution parameter P of the ethylene/-
5 olefin/non-conjugated polyene copolymer (A), as
determined by the following measuring method (X), have a
relationship of Pmax/Pmin≦1.4,
measuring method (X): a test sample obtained by
dissolving the ethylene/-olefin/non-conjugated polyene
10 copolymer (A) in cyclohexane is subjected to measurement
with GPC-offline-FTIR using cyclohexane as an eluent
under the conditions of a flow rate of 1.0 ml/min and a
temperature of 60°C, and a peak intensity ratio (A721 cm-
1/A4320 cm-1) of a maximum peak (A721 cm-1) of the
15 resulting spectrum in the range of 721±20 cm-1 to a
maximum peak (A4320 cm-1) thereof in the range of 4320±20
cm-1 is regarded as an ethylene distribution parameter P,
and
(2) the B value of the ethylene/C3-C20 -olefin
20 copolymer (C), which is represented by the following
formula (i), is not more than 1.05,
[0012] B value = [EX]/(2[E]×[X]) (i)
wherein [E] and [X] are molar fractions of ethylene and
the -olefin of 3 to 20 carbon atoms, respectively, and
8
[EX] is a fraction of dyad sequence of ethylene/-olefin
of 3 to 20 carbon atoms.
From the viewpoint of compatibility, the numberaverage
molecular weight of the polyolefin resin (B) in
5 terms of polystyrene, as measured by gel permeation
chromatography (GPC), is preferably not less than 10,000.
From the viewpoint of compatibility, the number-average
molecular weight of the ethylene/C3-C20 -olefin
copolymer (C) is preferably in the range of 2500 to 5000.
10 [0013] From the viewpoint of inhibition of
fogging and tackiness of the resulting molded product
caused by a low-molecular weight component, it is
preferable that the ethylene/-olefin/non-conjugated
polyene copolymer (A) satisfies the following
15 requirements:
(1) the content of constituent units derived from
ethylene is in the range of 50 to 90% by mol,
(2) the content of constituent units derived from
the non-conjugated polyene is in the range of 0.1 to 5%
20 by mol,
(3) the intrinsic viscosity [] is in the range of
0.5 to 5.0 dl/g, and
(4) the B value represented by the following formula
(ii) is not more than 1.05,
9
B value = ([EX]+2[Y])/{2[E]×([X]+[Y])} (ii)
wherein [E], [X] and [Y] are molar fractions of ethylene,
the -olefin of 3 to 20 carbon atoms and the nonconjugated
polyene, respectively, and [EX] is a fraction
5 of dyad sequence of ethylene/-olefin of 3 to 20 carbon
atoms,
and
the content of constituent units derived from
ethylene in the ethylene/C3-C20 -olefin copolymer (C) is
10 in the range of 50 to 90% by mol.
[0014] (3) The intrinsic viscosity [] is
preferably in the range of 0.5 to 5.0 dl/g from the
viewpoint of mechanical strength of the resulting rubber
molded product.
15 The ethylene/-olefin/non-conjugated polyene
copolymer (A) and/or the ethylene/C3-C20 -olefin
copolymer (C) is preferably obtained by polymerization
using a catalyst having a structure represented by the
following formula (I):
20 [0015]
10
The rubber composition of the invention preferably
contains the polyolefin resin (B) in an amount of 5 to
100 parts by weight and/or the ethylene/C3-C20 -olefin
5 copolymer (C) in an amount of 1 to 50 parts by weight,
based on 100 parts by weight of the ethylene/-
olefin/non-conjugated polyene copolymer (A).
[0016] In the rubber composition of the
invention, the polyolefin resin (B) preferably contains a
10 polyethylene resin, a crystalline ethylene/-olefin
copolymer of ethylene and an -olefin or a polypropylene
resin from the viewpoint of keeping rubber elasticity.
[0017] In the rubber composition of the
invention, the constituent units derived from the non15
conjugated polyene of the component (A) are preferably
constituent units derived from at least one nonconjugated
polyene selected from the group consisting of
11
5-ethylidene-2-norbornene (ENB) and 5-vinyl-2-norbornene
(VNB).
[0018] The rubber composition of the invention
preferably further comprises a reinforcing agent from the
5 viewpoint of hardness balance of the resulting molded
product.
The reinforcing agent is preferably carbon black.
[0019] In the rubber composition of the
invention, the carbon black is preferably contained in an
10 amount of 20 to 200 parts by weight based on 100 parts by
weight of the ethylene/-olefin/non-conjugated polyene
copolymer (A) from the viewpoints of reinforcing effect
and cost.
[0020] It is preferable that the rubber
15 composition of the invention is obtained by alloying the
ethylene/-olefin/non-conjugated polyene copolymer (A)
with the polyolefin resin (B) by means of an extruder,
because homogenous mixing is feasible.
[0021] It is preferable that the rubber
20 composition of the invention is obtained by alloying an
ethylene/-olefin/non-conjugated polyene copolymer
composition (A’) that is obtained by mixing the
ethylene/-olefin/non-conjugated polyene copolymer (A)
12
with a softener (X), with the polyolefin resin (B) by
means of an extruder.
[0022] In the rubber composition of the
invention, the softener (X) is preferably at least one
5 softener selected from the group consisting of mineral
oil and an ethylene/C3-C20 -olefin copolymer having a
number-average molecular weight in terms of polystyrene,
as measured by gel permeation chromatography (GPC), of
2500 to 5000 from the viewpoint of compatibility. The
10 softener (X) is more preferably an ethylene/propylene
copolymer from the viewpoint of compatibility.
[0023] In the rubber composition of the
invention, the softener (X) is preferably contained in an
amount of 0.1 to 120 parts by weight based on 100 parts
15 by weight of the ethylene/-olefin/non-conjugated polyene
copolymer (A).
The rubber composition of the invention preferably
further comprises paraffinic oil (D), and the paraffinic
oil (D) is contained in an amount of preferably 1 to 200
20 parts by weight, more preferably 1 to 50 parts by weight,
based on 100 parts by weight of the ethylene/C3-C20 -
olefin/non-conjugated polyene copolymer (A)
[0024] The thermoplastic elastomer of the present
invention is obtained by treating the above-mentioned
13
rubber composition and a polypropylene-based resin
through dynamic crosslinking in the presence of a
crosslinking agent.
The crosslinked product of the present invention is
5 obtained by crosslinking the above-mentioned rubber
composition.
[0025] The foamed product of the present
invention is obtained by crosslinking and foaming the
above-mentioned rubber composition.
10 The part for automobiles, the part for ships, the
part for civil engineering and construction, the medical
part, the part for electric/electronic components, the
part for transportation means, the sheet, the shoe, the
tire sidewall, the tire tube, the covered electric wire,
15 the electrically insulating part, the household rubber
article, the part for leisure, the coating material, the
adhesive or the like of the present invention is obtained
by the use of the above-mentioned rubber composition.
[0026] The rubber composition of the invention
20 preferably comprises:
100 parts by weight of an ethylene/C3-C20 -
olefin/non-conjugated polyene copolymer (A) satisfying
the following requirements:
14
(1) the content of constituent units derived from
ethylene is in the range of 50 to 90% by mol,
(2) the content of constituent units derived from
the non-conjugated polyene is in the range of 0.1 to 5%
5 by mol,
with the proviso that the total of the content (1)
of constituent units derived from ethylene, the content
of constituent units derived from the -olefin of 3 to 20
carbon atoms and the content (2) of constituent units
10 derived from the non-conjugated polyene is 100% by mol,
(3) the intrinsic viscosity [] is in the range of
0.5 to 5.0 dl/g, and
(4) the B value represented by the following formula
(ii) is not more than 1.05,
15 B value = ([EX]+2[Y])/{2[E]×([X]+[Y])} (ii)
wherein [E], [X] and [Y] are molar fractions of ethylene,
the -olefin of 3 to 20 carbon atoms and the nonconjugated
polyene, respectively, and [EX] is a fraction
of dyad sequence of ethylene/-olefin of 3 to 20 carbon
20 atoms,
(5) a maximum value Pmax and a minimum value Pmin of
an ethylene distribution parameter P of the copolymer
(A), as determined by the following measuring method (X),
have a relationship of Pmax/Pmin≦1.4,
15
measuring method (X): a test sample obtained by
dissolving the copolymer (A) in cyclohexane is subjected
to measurement with GPC-offline-FTIR using cyclohexane as
an eluent under the conditions of an eluent flow rate of
5 1.0 ml/min and a temperature of 60°C, and a peak
intensity ratio (A721 cm-1/A4320 cm-1) of a maximum peak
(A721 cm-1) of the resulting spectrum in the range of
721±20 cm-1 to a maximum peak (A4320 cm-1) thereof in the
range of 4320±20 cm-1 is determined, and
10 (6) the copolymer (A) is obtained by polymerization
using a catalyst having a structure represented by the
following formula (I):
[0027]
15 and
16
1 to 50 parts by weight of an ethylene/C3-C20 -
olefin copolymer (C) satisfying the following
requirements:
(1) the content of constituent units derived from
5 ethylene is in the range of 50 to 90% by mol,
with the proviso that the total of the content (1)
of constituent units derived from ethylene and the
content of constituent units derived from the -olefin of
3 to 20 carbon atoms is 100% by mol,
10 (4) the B value represented by the above formula
(ii) is not more than 1.05,
(6) the copolymer (C) is obtained by polymerization
using a catalyst having a structure represented by the
above formula (I), and
15 (7) the number-average molecular weight is in the
range of 2500 to 5000.
[0028] The rubber composition of the invention
preferably further comprises paraffinic oil (D), and the
paraffinic oil (D) is preferably contained in an amount
20 of 1 to 50 parts by weight based on 100 parts by weight
of the ethylene/C3-C20 -olefin/non-conjugated polyene
copolymer (A).
[0029] The solution containing the component (A)
and the component (C) of the present invention is
17
obtained by dissolving an ethylene/C3-C20 -olefin/nonconjugated
polyene copolymer (A) and an ethylene/C3-C20
-olefin copolymer (C) in an aliphatic hydrocarbon
solvent,
5 said ethylene/C3-C20 -olefin/non-conjugated polyene
copolymer (A) satisfying the following requirements:
(1) the content of constituent units derived from
ethylene is in the range of 50 to 90% by mol,
(2) the content of constituent units derived from
10 the non-conjugated polyene is in the range of 0.1 to 5%
by mol,
with the proviso that the total of the content (1)
of constituent units derived from ethylene, the content
of constituent units derived from the -olefin of 3 to 20
15 carbon atoms and the content (2) of constituent units
derived from the non-conjugated polyene is 100% by mol,
(3) the intrinsic viscosity [] is in the range of
0.5 to 5.0 dl/g, and
(4) the B value represented by the following formula
20 (ii) is not more than 1.05,
B value = ([EX]+2[Y])/{2[E]×([X]+[Y])} (ii)
wherein [E], [X] and [Y] are molar fractions of ethylene,
the -olefin of 3 to 20 carbon atoms and the nonconjugated
polyene, respectively, and [EX] is a fraction
18
of dyad sequence of ethylene/-olefin of 3 to 20 carbon
atoms,
(5) a maximum value Pmax and a minimum value Pmin of
an ethylene distribution parameter P of the copolymer
5 (A), as determined by the following measuring method (X),
have a relationship of Pmax/Pmin≦1.4,
measuring method (X): a test sample obtained by
dissolving the copolymer (A) in cyclohexane is subjected
to measurement with GPC-offline-FTIR using cyclohexane as
10 an eluent under the conditions of an eluent flow rate of
1.0 ml/min and a temperature of 60°C, and a peak
intensity ratio (A721 cm-1/A4320 cm-1) of a maximum peak
(A721 cm-1) of the resulting spectrum in the range of
721±20 cm-1 to a maximum peak (A4320 cm-1) thereof in the
15 range of 4320±20 cm-1 is determined, and
(6) the copolymer (A) is obtained by polymerization
using a catalyst having a structure represented by the
following formula (I):
[0030]
19
said ethylene/C3-C20 -olefin copolymer (C)
satisfying the following requirements:
(1) the content of constituent units derived from
5 ethylene is in the range of 50 to 90% by mol,
with the proviso that the total of the content (1)
of constituent units derived from ethylene and the
content of constituent units derived from the -olefin of
3 to 20 carbon atoms is 100% by mol,
10 (4) the B value represented by the above formula
(ii) is not more than 1.05,
(6) the copolymer (C) is obtained by polymerization
using a catalyst having a structure represented by the
above formula (I), and
15 (7) the number-average molecular weight is in the
range of 2500 to 5000.
20
[0031] The solution containing the component (A)
and the component (C) of the invention preferably further
comprises paraffinic oil (D).
The aliphatic hydrocarbon solvent is preferably
5 hexane.
[0032] The rubber composition of the invention is
obtained by removing the aliphatic hydrocarbon solvent
from the above-mentioned solution.
The olefin-based thermoplastic elastomer of the
10 present invention is obtained by treating the abovementioned
rubber composition and a polypropylene-based
resin through dynamic crosslinking in the presence of a
crosslinking agent.
[0033] The hose of the present invention has a
15 tensile creep value (change of elongation in heating of
the hose from 25°C to 80°C at a rate of 2°C/min under a
constant load of 0.6 MPa using a viscoelasticity tester)
of not more than 2.5%, preferably not more than 2%, more
preferably not more than 1.5%.
20 [0034] The hose of the invention has a shrinkage
ratio (change of length in crosslinking of an
unvulcanized hose) of usually not more than 4.0%,
preferably not more than 3.0%, more preferably not more
than 2.5%.
21
[0035] The part for automobiles, the part for
ships, the part for civil engineering and construction,
the medical part, the part for electric/electronic
components, the part for transportation means, the sheet,
5 the shoe, the tire sidewall, the tire tube, the covered
electric wire, the electrically insulating part, the
household rubber article, the part for leisure, the
coating material, the adhesive or the like of the present
invention is obtained by the use of the above-mentioned
10 rubber composition or its crosslinked product.
EFFECT OF THE INVENTION
[0036] According to the present invention (1), a
rubber composition which can be improved in compatibility
15 of the ethylene/-olefin/non-conjugated polyene copolymer
with the polyolefin resin and is capable of inhibiting
formation of a gel-like substance, and various molded
products which are formed from the composition and are
excellent in rigidity, compression set and shape memory
20 property can be provided.
[0037] In the present invention (2), by making
the B value be not more than 1.05 using the above
catalyst, compatibility of the ethylene/-olefin/nonconjugated
polyene copolymer (A) with the ethylene/-
22
olefin copolymer (C) can be improved, and by making the
number-average molecular weight of the ethylene/C3-C20 -
olefin copolymer (C) be not less than 2500, the
ethylene/C3-C20 -olefin copolymer (C) can be made
5 nonvolatile. Therefore, a rubber molded product formed
from the rubber composition of the present invention (2)
is excellent in mechanical strength (tensile strength,
elongation) and heat aging resistance and is inhibited
from fogging and tackiness caused by evaporation or
10 separation of a low-molecular weight component.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] Fig. 1 is a schematic view of a twin-screw
three-stage vented extruder used in Example (I) of the
15 present invention (1).
Fig. 2 shows a shape of a beaker necessary for
measuring a quantity of fogging.
Fig. 3 is a vertical sectional view showing the
beaker 3 of Fig. 2 containing a rubber molded product (in
20 the form of a disc having a diameter of 80 mm and a
thickness of 2 mm) of the present invention (2) as a
sample 4, an aluminum foil 2 and a cooling plate 1
maintained at 20°C, which are set on the beaker in order
to measure a quantity of fogging.
23
Description of numerical symbols
[0039] 1: cooling plate maintained at 20°C
2: aluminum foil
3: beaker of Fig. 2
5 4: sample
BEST MODE FOR CARRYING OUT THE INVENTION
[0040] The present invention is described in
detail hereinafter.
10 The rubber composition of the invention comprises an
ethylene/-olefin/non-conjugated polyene copolymer (A),
and a polyolefin resin (B) having a number-average
molecular weight in term of polystyrene, as measured by
gel permeation chromatography (GPC), of not less than
15 10,000 and/or an ethylene/C3-C20 -olefin copolymer (C)
having a number-average molecular weight of 2500 to 5000,
and is characterized in that
(1) a maximum value Pmax and a minimum value Pmin of
an ethylene distribution parameter P of the ethylene/-
20 olefin/non-conjugated polyene copolymer (A), as
determined by the following measuring method (X), have a
relationship of Pmax/Pmin≦1.4 [measuring method (X): a
test sample obtained by dissolving the ethylene/-
olefin/non-conjugated polyene copolymer (A) in
24
cyclohexane is subjected to measurement with GPC-offline-
FTIR using cyclohexane as an eluent under the conditions
of a flow rate of 1.0 ml/min and a temperature of 60°C,
and a peak intensity ratio (A721 cm-1/A4320 cm-1) of a
5 maximum peak (A721 cm-1) of the resulting spectrum in the
range of 721±20 cm-1 to a maximum peak (A4320 cm-1)
thereof in the range of 4320±20 cm-1 is regarded as an
ethylene distribution parameter P], and
(2) the B value of the ethylene/C3-C20 -olefin
10 copolymer (C), which is represented by the following
formula (i), is not more than 1.05,
[0041] B value = [EX]/(2[E]×[X]) (i)
wherein [E] and [X] are molar fractions of ethylene and
the -olefin of 3 to 20 carbon atoms, respectively, and
15 [EX] is a fraction of dyad sequence of ethylene/-olefin
of 3 to 20 carbon atoms.
That is to say, in the rubber composition of the
invention, the following first and second embodiments are
included.
20 [0042] The first embodiment of the invention
(referred to as “present invention (1)” hereinafter) is a
rubber composition comprising an ethylene/-olefin/nonconjugated
polyene copolymer (A) and a polyolefin resin
(B), among the rubber compositions comprising an
25
ethylene/-olefin/non-conjugated polyene copolymer (A),
and a polyolefin resin (B) and/or an ethylene/C3-C20 -
olefin copolymer (C).
[0043] The second embodiment of the invention
5 (referred to as “present invention (2)” hereinafter) is a
rubber composition comprising an ethylene/-olefin/nonconjugated
polyene copolymer (A) and an ethylene/C3-C20
-olefin copolymer (C), among the rubber compositions
comprising an ethylene/-olefin/non-conjugated polyene
10 copolymer (A), and a polyolefin resin (B) and/or an
ethylene/C3-C20 -olefin copolymer (C).
[0044] First, the present invention (1) is
described in detail.
Ethylene/-olefin/non-conjugated polyene copolymer (A)
15 The ethylene/-olefin/non-conjugated polyene
copolymer (A) for use in the present invention (1) is a
copolymer obtained by polymerization using a metallocene
catalyst having a structure represented by the following
formula (I), and a maximum value Pmax and a minimum value
20 Pmin of an ethylene distribution parameter P of the
ethylene/-olefin/non-conjugated polyene copolymer (A),
as determined by the above measuring method (X), have a
relationship of Pmax/Pmin≦1.4
[0045]
26
The ethylene/-olefin/non-conjugated polyene
copolymer (A) for use in the present invention (1) is a
polymer in which ethylene, an -olefin and a non-
5 conjugated polyene are copolymerized, preferably they are
copolymerized at random.
[0046] As the -olefin, an -olefin of 3 to 20
carbon atoms is usually used. Examples of such -olefins
include propylene, 1-butene, 1-pentene, 1-hexene, 4-
10 methyl-1-pentene, 1-octene, 1-nonene, 1-decene, 1-
undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-
pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene,
1-nonadecene, 1-eicosene, 9-methyl-1-decene, 11-methyl-1-
dodecene and 12-ethyl-1-tetradecene. Of these, -olefins
15 of 3 to 10 carbon atoms are preferable, and in
particular, propylene, 1-butene, 1-hexene and 1-octene
27
are preferably used. These -olefins may be used singly
or may be used in combination of two or more kinds.
[0047] As the non-conjugated polyene, a cyclic or
chain non-conjugated polyene is used. Examples of the
5 cyclic non-conjugated polyenes include 5-ethylidene-2-
norbornene, dicyclopentadiene, 5-vinyl-2-norbornene,
norbornadiene and methyltetrahydroindene. Examples of
the chain non-conjugated polyenes include 1,4-hexadiene,
7-methyl-1,6-octadiene, 4-ethylidene-8-methyl-1,7-
10 nonadiene and 4-ethylidene-1,7-undecadiene. Of these, 5-
ethylidene-2-norbornene, dicyclopentadiene and 5-vinyl-2-
norbornene are preferably used. These cyclic or chain
non-conjugated polyenes may be used singly or may be used
in combination of two or more kinds.
15 [0048] With regard to the ethylene/-olefin/nonconjugated
polyene copolymer (A) for use in the present
invention (1), a maximum value Pmax and a minimum value
Pmin of its ethylene distribution parameter P, as
determined by the aforesaid measuring method (X), have a
20 relationship of Pmax/Pmin≦1.4.
[0049] The ethylene distribution parameter P is
an indication of a content of the constituent units
derived from ethylene in the ethylene/-olefin/nonconjugated
polyene copolymer (A) in the measured
28
fraction, and a larger P value indicates a larger content
of the constituent units derived from ethylene. It is
presumed that the maximum peak (A721 cm-1) in the range of
721±20 cm-1 in the IR spectrum indicates a peak derived
5 from C-H rocking vibration of the constituent units
derived from ethylene and the maximum peak (A4320 cm-1) in
the range of 4320±20 cm-1 in the IR spectrum indicates a
peak derived from C-H deformation vibration common to
olefin structures.
10 [0050] The ethylene distribution parameter P can
be measured by the measuring method described in the
later-described Example (1).
Because the ethylene/-olefin/non-conjugated polyene
copolymer (A) for use in the present invention (1) has a
15 Pmax/Pmin value of the above range, a difference in
content of the constituent units derived from ethylene
between a high-molecular weight part and a low-molecular
weight part of the copolymer (A) is small, and the
copolymer (A) has excellent compatibility with the
20 polyolefin resin (B) such as a polyethylene resin or a
polypropylene resin. By preparing the copolymer (A)
through polymerization using a metallocene catalyst
having a structure represented by the above formula (I),
the Pmax/Pmin value can be determined in the above range.
29
[0051] As described above, the ethylene/-
olefin/non-conjugated polyene copolymer (A) is a
copolymer obtained by polymerization using a metallocene
catalyst, preferably a metallocene catalyst having a
5 structure represented by the above formula (I).
[0052] The above formula (I) represents [N-(1,1-
dimethylethyl)-1,1-dimethyl-1-[(1,2,3,3A,8A-)-1,5,6,7-
tetrahydro-2-methyl-S-indacene-1-yl]silaneaminate(2-)-
N][(1,2,3,4-)-1,3-pentadiene]-titanium (another name:
10 (t-butylamido)-dimethyl(5-2-methyl-s-indacene-1-
yl)silane-titanium(II)1,3-pentadiene).
[0053] The metallocene catalyst of a structure
represented by the formula (I) can be synthesized by the
process described in National Publication of
15 International Patent No. 522398/2001.
By the use of a compound analogous to the
metallocene catalyst, the Pmax/Pmin value can be
determined in the above range, and the copolymer (A) has
excellent compatibility with the polyolefin resin (B), so
20 that use of such a compound is preferable.
[0054] As the ethylene/-olefin/non-conjugated
polyene copolymer (A) for use in the present invention
(1), the following one is preferable.
30
That is to say, the content of the constituent units
which constitute the ethylene/-olefin/non-conjugated
polyene copolymer (A) and are derived from ethylene is in
the range of preferably 50 to 90% by mol, more preferably
5 60 to 80% by mol, and the content of the constituent
units derived from the -olefin is in the range of
preferably 10 to 50% by mol, more preferably 20 to 40% by
mol, with the proviso that the total of the constituent
units derived from ethylene and the constituent units
10 derived from the -olefin is 100% by mol.
[0055] Further, the content of the constituent
units which constitute the ethylene/-olefin/nonconjugated
polyene copolymer (A) and are derived from the
non-conjugated polyene is in the range of preferably 0.1
15 to 5% by mol, more preferably 0.1 to 3% by mol, in 100 %
by mol of the total of all the constituent units in the
copolymer (A).
[0056] When the contents of the constituent units
are in the above ranges, the copolymer (A) has excellent
20 compatibility with the polyolefin resin, so that such
contents are preferable.
The intrinsic viscosity [] of the copolymer (A) for
use in the present invention (1) is in the range of
usually 0.5 to 5.0 dl/g, preferably 1.0 to 5.0 dl/g, more
31
preferably 1.5 to 4.0 dl/g, still more preferably 1.5 to
3.5 dl/g. If the intrinsic viscosity is less than 0.5
dl/g, there is a tendency of deterioration of
processability or shortage of strength because of too low
5 viscosity. If the intrinsic viscosity exceeds 5.0 dl/g,
processability tends to be deteriorated because of too
high viscosity.
[0057] The number-average molecular weight (Mn)
(in terms of polystyrene) of the copolymer (A) for use in
10 the present invention (1), as measured by gel permeation
chromatography (GPC), is in the range of usually 10,000
to 1,000,000, preferably 10,000 to 200,000. The
molecular weight distribution (Mw/Mn) calculated using
the weight-average molecular weight (Mw) and the number15
average molecular weight (Mn) is in the range of usually
2.0 to 10.0, preferably 2.0 to 7.0, more preferably 2.0
to 5.0, still more preferably 2.0 to 4.0. When the
molecular weight distribution (Mw/Mn) is in the above
range, the copolymer (A) has excellent compatibility with
20 the polyolefin resin (B), so that such a molecular weight
distribution is preferable.
[0058] The polymerization process to produce the
copolymer (A) is not specifically restricted as long as
the polymerization is carried out using a metallocene
32
catalyst having a structure of the above formula or a
structure analogous thereto. In usual, the
polymerization is carried out by a continuous process or
a batch process wherein the metallocene catalyst is used
5 as a main catalyst, a boron-based compound such as
(C6H5)3CB(C6F5)4 is used as a cocatalyst, an organoaluminum
compound is used, an aliphatic hydrocarbon such as hexane
is used as a solvent, and a reactor equipped with a
stirrer is used.
10 [0059] As the metallocene catalyst having a
structure of the above formula (I) or a structure
analogous thereto, there can be mentioned a metallocene
compound having a structure represented by the following
formula (iii), preferably the following formula (iv),
15 (v), (vi), (vii) or (I), most preferably the following
formula (I).
[0060]
33
In the formula (iii), R’ is a hydrogen atom, a
hydrocarbyl group, a di(hydrocarbylamino) group or a
hydrocarbyleneamino group, and these groups have up to 20
carbon atoms.
5 [0061] R” is a hydrocarbyl group of 1 to 20
carbon atoms or a hydrogen atom.
M is titanium.
Y is –O-, -S-, -NR*-, -PR*-, -NR*2 or –PR*2.
[0062] Z* is –SiR*2-, –CR*2-, –SiR*2SiR*2-, –
10 CR*2CR*2-, –CR*=CR*-, –CR*2SiR*2- or –GeR*2-.
When plural R* are present, they are each
independently a hydrogen atom or a group containing at
least one group selected from the group consisting of a
hydrocarbyl group, a hydrocarbyloxy group, a silyl group,
15 a halogenated alkyl group and a halogenated aryl group.
This R* contains 2 to 20 atoms, and two R* (R* is not a
hydrogen atom) of Z* may arbitrarily form a ring, and R*
of Z* and R* of Y may form a ring.
[0063] X is a monovalent anionic ligand group
20 having up to 60 atoms other than a class of ligands that
are cyclic delocalized -bonding ligand groups.
X’ is a neutral linking group having up to 20 atoms.
[0064] X” is a divalent anionic ligand group
having up to 60 atoms.
34
p is 0, 1 or 2, q is 0 or 1, and r is 0 or 1.
However, when p is 2, q and r are each 0, M is in an
oxidation state of +4 (or when Y is –NR*2 or –PR*2, M is
an oxidation state of +3), and X is an anionic ligand
5 selected from a halide group, a hydrocarbyl group, a
hydrocarbyloxy group, a di(hydrocarbyl)amide group, a
di(hydrocarbyl)phosphide group, a hydrocarbyl sulfide
group, a silyl group, derivatives obtained by halogensubstitution
of these groups, derivatives obtained by
10 di(hydrocarbylamino)-substitution of these groups,
derivatives obtained by hydrocarbyloxy-substitution of
these groups and derivatives obtained by
di(hydrocarbyl)phosphino-substitution of these groups,
and has up to 30 atoms other than hydrogen atom.
15 [0065] When r is 1, p and q are each 0, M is in
an oxidation state of +4, and X” is a dianionic ligand
selected from the group consisting of a hydrocarbazyl
group, an oxyhydrocarbyl group and a hydrocarbylenedioxy
group and has up to 30 atoms other than hydrogen atom.
20 [0066] When p is 1, q and r are each 0, M is in
an oxidation state of +3, and X is a stabilizing anionic
ligand group selected from the group consisting of allyl,
2-(N,N-dimethylamino)phenyl, 2-(N,N35
dimethylaminomethyl)phenyl and 2-(N,Ndimethylamino)
benzyl.
[0067] When p and r are each 0, q is 1, M is in
an oxidation state of +2, X’ is a neutral conjugated
5 diene or a neutral non-conjugated diene, which has been
arbitrarily substituted by one or more hydrocarbyl
groups, and this X’ has up to 40 carbon atoms and forms a
-complex together with M.
In the formula (iii), any one embodiment of the
10 following embodiments (1) to (4) is preferable.
[0068] (1) p is 2, q and r are each 0, M is in an
oxidation state of +4, and X is each independently
methyl, benzyl or a halide.
(2) q and q are each 0, r is 1, M is in an oxidation
15 state of +4, and X” is a 1,4-butadienyl group which forms
a metallacyclopentene ring together with M.
[0069] (3) p is 1, q and r are each 0, M is in an
oxidation state of +3, and X is 2-(N,Ndimethylamino)
benzyl.
20 (4) p and r are each 0, q is 1, M is in an oxidation
state of +2, and X’ is 1,4-diphenyl-1,3-butadiene or 1,3-
pentadiene.
[0070] In any one of the above embodiments (1) to
(4), it is more preferable that R” is a hydrogen atom or
36
a methyl group, and it is particularly preferable that R”
is a hydrogen atom.
[0071]
5 The above formula (iv) represents (tbutylamido)
dimethyl(5-2-methyl-s-indacene-1-yl)silanetitanium(
II)2,4-hexadiene.
[0072]
37
The above formula (v) represents (t-butylamido)-
dimethyl(5-2-methyl-s-indacene-1-yl)silanetitanium(
IV)dimethyl.
[0073]
5
The above formula (vi) represents (t-butylamido)-
dimethyl(5-2,3-dimethylindenyl)silane-titanium(II)1,4-
diphenyl-1,3-butadiene.
[0074]
10
38
The above formula (vii) represents (t-butylamido)-
dimethyl(5-2,3-dimethyl-s-indacene-1-yl)silanetitanium(
IV)dimethyl.
[0075]
5
The above formula (I) represents (t-butylamido)-
dimethyl(5-2-methyl-s-indacene-1-yl)silanetitanium(
II)1,3-pentadiene (another name: [N-(1,1-
dimethylethyl)-1,1-dimethyl-1-[(1,2,3,3A,8A-)-1,5,6,7-
10 tetrahydro-2-methyl-S-indacene-1-yl]silaneaminate(2-)-
N][(1,2,3,4-)-1,3-pentadiene]-titanium).
Examples of the boron-based compounds include
trimethylammonium tetrakis(pentafluorophenyl)borate,
di(hydrogenated tallow alkyl)methylammonium
15 tetrakis(pentafluorophenyl)borate, triethylammonium
tetrakis(pentafluorophenyl)borate, tripropylammonium
tetrakis(pentafluorophenyl)borate, tri(n-butyl)ammonium
39
tetrakis(pentafluorophenyl)borate, tri(sec-butyl)ammonium
tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium
tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium
n-butyltris(pentafluorophenyl)borate, N,N-
5 dimethylanilinium benzyltris(pentafluorophenyl)borate,
N,N-dimethylanilinium tetrakis(4-(t-butyldimethylsilyl)-
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,Ndiethylanilinium
tetrakis(pentafluorophenyl)borate, N,Ndimethyl-
2,4,6-trimethylanilinium
tetrakis(pentafluorophenyl)borate, trimethylammonium
tetrakis(2,3,4,6-tetrafluorophenyl)borate,
15 triethylammonium tetrakis(2,3,4,6-
tetrafluorophenyl)borate, tripropylammonium
tetrakis(2,3,4,6-tetrafluorophenyl)borate, N,Ndimethylanilinum
tetrakis(2,3,4,6-
tetrafluorophenyl)borate, N,N-diethylanilinum
20 tetrakis(2,3,4,6-tetrafluorophenyl)borate and N,Ndimethyl-
2,4,6-trimethylanilinum tetrakis(2,3,4,6-
tetrafluorophenyl)borate; dialkylammonium salts, such as
di(isopropyl)ammonium tetrakis(pentafluorophenyl)borate,
tri(n-butyl)ammonium tetrakis(2,3,4,6-
40
tetrafluorophenyl)borate, dimethyl(t-butyl)ammonium
tetrakis(2,3,4,6-tetrafluorophenyl)borate and
dicyclohexylammonium tetrakis(pentafluorophenyl)borate;
tri-substituted phosphonium salts, such as
5 triphenylphosphonium tetrakis(pentafluorophenyl)borate,
tri(o-tolyl)phosphonium tetrakis(pentafluorophenyl)borate
and tri(2,6-dimethylphenyl)phosphonium
tetrakis(pentafluorophenyl)borate; di-substituted oxonium
salts, such as diphenyloxonium
10 tetrakis(pentafluorophenyl)borate, di(o-tolyl)oxonium
tetrakis(pentafluorophenyl)borate and di(2,6-
dimethylphenyl)oxonium tetrakis(pentafluorophenyl)borate;
and di-substituted sulfonium salts, such as
diphenylsulfonium tetrakis(pentafluorophenyl)borate,
15 di(o-tolyl)sulfonium tetrakis(pentafluorophenyl)borate
and bis(2,6-dimethylphenyl)sulfonium
tetrakis(pentafluorophenyl)borate.
[0076] As the organoaluminum compound,
triisobutylaluminum (also referred to as “TIBA”
20 hereinafter) is preferable.
The polymerization temperature is in the range of
usually –20 to 200°C, preferably 0 to 150°C, more
preferably 0 to 100°C, and the pressure is usually more
than 0 but not more than 8 MPa (gauge pressure),
41
preferably more than 0 but not more than 5 MPa (gauge
pressure). When the reaction temperature and the
pressure are in the above ranges, the catalyst exhibits
excellent activity and the copolymer (A) can be favorably
5 produced, so that such a temperature and such a pressure
are preferable.
[0077] The amounts of the raw materials used in
the polymerization are as follows. In usual, the amount
of the -olefin is 0.2 to 1.0 mol and the amount of the
10 non-conjugated polyene is 0.02 to 0.10 mol, based on 1
mol of ethylene, and preferably, the amount of the -
olefin is 0.4 to 0.8 mol and the amount of the nonconjugated
polyene is 0.04 to 0.08 mol, based on 1 mol of
ethylene.
15 [0078] When ethylene is fed at a rate of 4.6
kg/hr, the metallocene catalyst is used at a rate of 0.03
to 0.11 mmol/hr, the cocatalyst is used at a rate of 0.10
to 0.46 mmol/hr, and the organoaluminum compound is used
at a rate of 0.6 to 3.0 mmol/hr, though the rates vary
20 depending upon the feed rates of the raw materials.
[0079] The polymerization time (average residence
time in the case where the copolymerization is carried
out by a continuous process) is in the range of usually
0.5 minutes to 5 hours, preferably 10 minutes to 3 hours,
42
though it varies depending upon the conditions such as
catalytic concentration and polymerization temperature.
In the copolymerization, a molecular weight modifier
such as hydrogen can be also used.
5 [0080] By the use of the copolymer (A) obtained
by polymerization under the above polymerization
conditions, the rubber composition of the present
invention (1) is excellent in compatibility of the
ethylene/-olefin/non-conjugated polyene copolymer with
10 the polyolefin resin and is inhibited from formation of a
gel-like substance. Further, a molded product formed
from the composition is excellent in rigidity,
compression set, shape memory property, etc.
[0081] Polyolefin resin (B)
15 Although the polyolefin resin (B) for use in the
present invention (1) is not specifically restricted, the
number-average molecular weight in terms of polystyrene,
as measured by gel permeation chromatography (GPC), is
preferably not less than 10,000. Examples of such
20 polyolefin resins include polyethylenes, such as an
ethylene homopolymer, high-density polyethylene (HDPE),
medium-density polyethylene (MDPE), low-density
polyethylene (LDPE) and linear low-density polyethylene
(LLDPE); crystalline ethylene/-olefin copolymers of
43
ethylene and -olefins of 3 to 20 carbon atoms,
preferably 3 to 8 carbon atoms; polypropylenes, such as a
propylene homopolymer, a propylene block copolymer and a
propylene random copolymer; and crystalline homopolymers
5 or copolymers of -olefins of 4 to 20 carbon atoms,
preferably 4 to 8 carbon atoms, such as 1-butene, 4-
methyl-1-pentene, 1-hexene, 1-heptene and 1-octene.
[0082] The number-average molecular weight (Mn)
is in the range of usually 10,000 to 1,000,000,
10 preferably 10,000 to 200,000.
The melting point of the polyolefin resin (B) is
preferably not higher than 250°C. Of the above resins,
preferable are polyethylene, a crystalline ethylene/-
olefin copolymer and polypropylene.
15 [0083] As the polyolefin resin (B) for use in the
present invention (1), a resin produced by a process
hitherto publicly known may be used, or a commercially
available one may be used.
In the rubber composition of the present invention
20 (1), the polyolefin resin (B) is contained in an amount
of usually 5 to 100 parts by weight, preferably 10 to 80
parts by weight, more preferably 15 to 50 parts by
weight, particularly preferably 15 to 25 parts by weight,
based on 100 parts by weight of the ethylene/-
44
olefin/non-conjugated polyene copolymer (A). When the
polyolefin resin (B) is used in such an amount, rubber
elasticity can be maintained.
[0084] In particular, polyethylene and the
5 crystalline ethylene/-olefin copolymer among the above
polyolefin resins (B) contribute to allowing a
reinforcing agent and a filler to increase product
hardness as high as carbon black, and besides, they
decrease compound viscosity at the processing
10 temperature. Therefore, they are used as compounding
agents having an effect of enhancing processability.
[0085] Reinforcing agent
In the rubber composition of the present invention
(1), a reinforcing agent may be contained in addition to
15 the ethylene/-olefin/non-conjugated copolymer (A) and
the polyolefin resin (B). When the reinforcing agent is
contained, balance between processability of the rubber
composition and hardness of a molded product obtained
from the rubber composition is excellent, so that use of
20 the reinforcing agent is preferable.
[0086] Examples of the reinforcing agents include
carbon black, finely powdered silicic acid and silica.
Of these, carbon black is preferable from the viewpoints
of reinforcing effect and cost.
45
As the carbon black, commercially available various
ones can be used without any restriction. Specifically,
FEF carbon black (available from Asahi Carbon Co., Ltd.,
trade name: Asahi #60G) is employable.
5 [0087] Examples of silica include fumed silica
and precipitated silica. The silica may have been
surface-treated with reactive silane, such as
hexamethyldisilazane, chlorosilane or alkoxysilane, lowmolecular
siloxane, or the like. The specific surface
10 area (BET method) of such silica is preferably not less
than 50 m2/g, more preferably 100 to 400 m2/g.
[0088] The type and the amount of the reinforcing
agent added can be appropriately selected according to
the use purpose.
15 The amount of the reinforcing agent added is in the
range of usually not more than 300 parts by weight,
preferably not more than 200 parts by weight, based on
100 parts by weight of the ethylene/-olefin/nonconjugated
polyene copolymer (A). In the case where
20 carbon black is used as the reinforcing agent, the amount
of the carbon black added is in the range of usually 20
to 200 parts by weight, preferably 50 to 200 parts by
weight, more preferably 60 to 180 parts by weight, based
on 100 parts by weight of the ethylene/-olefin/non46
conjugated polyene copolymer (A). When carbon black is
used in such an amount, a molded product obtained from
the rubber composition is excellent in balance of
hardness, so that such an amount is preferable.
5 [0089] Softener
In the rubber composition of the present invention
(1), a softener may be further contained. The purpose
and the effect of the softener vary depending upon the
stage of the preparation process of the rubber
10 composition where the softener is added. Therefore,
there are softeners of various types. The softener is
described in the later-described process for preparing a
rubber composition.
[0090] Other additives
15 In the rubber composition of the present invention
(1), other additives may be further contained. Examples
of the other additives include blowing agent, filler,
vulcanizing agent, vulcanization accelerator,
vulcanization acceleration assistant, blowing assistant,
20 processing aid, anti-aging agent, heat stabilizer,
weathering stabilizer, antistatic agent, colorant,
lubricant and thickening agent.
[0091] In the case where the rubber composition
of the present invention (1) is crosslinked or foamed to
47
form a foamed product, any of physical blowing and
chemical blowing may be used, and in the case of the
chemical blowing, the following blowing agent is usually
used.
5 [0092] Examples of the blowing agents include:
inorganic blowing agents, such as sodium
bicarbonate, sodium carbonate, ammonium bicarbonate,
ammonium carbonate and ammonium nitrite;
nitroso compounds, such as N,N’-dimethyl-N,N’-
10 dinitrosoterephthalamide and N,N’-
dinitrosopentamethylenetetramine;
azo compounds, such as azodicarbonamide,
azobisisobutylonitrile, azobiscyclohexylnitrile,
azodiaminobenzene and barium azodicarboxylate;
15 sulfonylhydrazide compounds, such as
benzenesulfonylhydrazide, toluenesulfonylhydrazide, p,p’-
oxybis(benzenesulfonylhydrazide) (OBSH) and
diphenylsulfone-3,3’-disulfonylhydrazide; and
azide compounds, such as calcium azide, 4,4’-
20 diphenyldisulfonyl azide and p-toluenesulfonyl azide.
[0093] In the case where the blowing agent is
contained in the rubber composition of the present
invention (1), the amount of the blowing agent is in the
range of usually 0.01 to 20 parts by weight, preferably
48
0.1 to 10 parts by weight, based on 100 parts by weight
of the ethylene/-olefin/non-conjugated polyene copolymer
(A). When the blowing agent is used in such an amount,
the rubber composition has excellent foaming property, so
5 that such an amount is preferable.
[0094] Examples of the fillers include inorganic
fillers, such as light calcium carbonate, heavy calcium
carbonate, calcium oxide, talc and clay. The type and
the amount of the inorganic filler can be appropriately
10 selected according to the use purpose.
[0095] The amount of the inorganic filler added
is in the range of usually not more than 300 parts by
weight, preferably not more than 200 parts by weight,
more preferably 50 to 150 parts by weight, based on 100
15 parts by weight of the ethylene/-olefin/non-conjugated
polyene copolymer (A).
[0096] Examples of the vulcanizing agents include
sulfur, a sulfur compound and an organic peroxide.
Examples of sulfur include powdered sulfur,
20 precipitated sulfur, colloidal sulfur, surface-treated
sulfur and insoluble sulfur.
[0097] Examples of the sulfur compounds include
sulfur chloride, sulfur dichloride and high-molecular
polysulfides. Further, sulfur compounds which release
49
active sulfur at the vulcanization temperature to carry
out vulcanization, such as morpholine disulfide,
alkylphenol disulfide, tetramethylthiuram disulfide and
dipentamethylenethiuram tetrasulfide, are also
5 employable.
[0098] Examples of the organic peroxides include
dicumyl peroxide, di-t-butyl peroxide, di-t-butylperoxy-
3,3,5-trimethylcyclohexane, t-butyl hydroperoxide, tbutylcumyl
peroxide, benzoyl peroxide, 2,5-dimethyl-2,5-
10 di(t-butylperoxy)hexyne-3, 2,5-dimethyl-2,5-
di(benzoylperoxy)hexane, 2,5-dimethyl-2,5-mono(tbutylperoxy)
hexane and ,’-bis(t-butylperoxy-misopropyl)
benzene.
[0099] In the case where the rubber composition
15 is crosslinked, the vulcanizing agent is used in an
amount of usually 0.05 to 10 parts by weight, preferably
0.1 to 5 parts by weight, more preferably 0.3 to 3 parts
by weight, based on 100 parts by weight of the
ethylene/-olefin/non-conjugated polyene copolymer (A).
20 [0100] Examples of other vulcanizing agents
include N-cyclohexyl-2-benzothiazyl sulfenamide and
dithiodimorpholine.
50
When sulfur or the sulfur compound is used as the
vulcanizing agent, it is preferable to use a
vulcanization accelerator in combination.
[0101] Examples of the vulcanization accelerators
5 include:
thiazole type compounds, such as N-cyclohexyl-2-
benzothiazole sulfenamide, N-oxydiethylene-2-
benzothiazole sulfenamide, N,N’-diisopropyl-2-
benzothiazole sulfenamide, 2-mercaptobenzothiazole, 2-
10 (2,4-dinitrophenyl)mercaptobenzothiazole, 2-(2,6-diethyl-
4-morpholinothio)benzothiazole and dibenzothiazyl
disulfide;
guanidine compounds, such as diphenylguanidine,
triphenylguanidine, diorthonitrileguanidine, orthonitrile
15 biguanide and diphenylguanidine phthalate;
aldehydeamine and aldehyde-ammonia type compounds,
such as acetaldehyde-aniline reaction product,
butylaldehyde-aniline condensate, hexamethylenetetramine
and acetaldehyde ammonia;
20 imidazoline type compounds, such as 2-
mercaptoimidazoline;
thiourea type compounds, such as thiocarbanilide,
diethylthiourea, dibutylthiourea, trimethylthiourea and
diorthotolylthiourea;

I/We Claim:
1. A rubber composition comprising an ethylene/-
olefin/non-conjugated polyene copolymer (A) and an
ethylene/C3-C20 -olefin copolymer (C), wherein
5 (1) a maximum value Pmax and a minimum value Pmin of
an ethylene distribution parameter P of the ethylene/-
olefin/non-conjugated polyene copolymer (A), as
determined by the following measuring method (X), have a
relationship of Pmax/Pmin≦1.4,
10 measuring method (X): a test sample obtained by
dissolving the ethylene/-olefin/non-conjugated polyene
copolymer (A) in cyclohexane is subjected to measurement
with GPC-offline-FTIR using cyclohexane as an eluent
under the conditions of a flow rate of 1.0 ml/min and a
15 temperature of 60°C, and a peak intensity ratio (A721 cm-
1/A4320 cm-1) of a maximum peak (A721 cm-1) of the
resulting spectrum in the range of 721±20 cm-1 to a
maximum peak (A4320 cm-1) thereof in the range of 4320±20
cm-1 is regarded as an ethylene distribution parameter P,
20 and
(2) the B value of the ethylene/C3-C20 -olefin
copolymer (C), which is represented by the following
formula (i), is not more than 1.05,
B value = [EX]/(2[E]×[X]) (i)
25 wherein [E] and [X] are molar fractions of ethylene and
the -olefin of 3 to 20 carbon atoms, respectively, and
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[EX] is a fraction of dyad sequence of ethylene/-olefin
of 3 to 20 carbon atoms.
2. The rubber composition as claimed in claim 1,
5 wherein the ethylene/-olefin/non-conjugated polyene
copolymer (A) satisfies the following requirements:
(1) the content of constituent units derived from
ethylene is in the range of 50 to 90% by mol,
(2) the content of constituent units derived from
10 the non-conjugated polyene is in the range of 0.1 to 5%
by mol,
(3) the intrinsic viscosity [] is in the range of
0.5 to 5.0 dl/g, and
(4) The B value represented by the following formula
15 (ii) is not more than 1.05,
B value = ([EX]+2[Y])/{2[E]×([X]+[Y])} (ii)
wherein [E], [X] and [Y] are molar fractions of ethylene,
the -olefin of 3 to 20 carbon atoms and the nonconjugated
polyene, respectively, and [EX] is a fraction
20 of dyad sequence of ethylene/-olefin of 3 to 20 carbon
atoms,
and
the content of constituent units derived from
ethylene in the -olefin copolymer (C) is in the range of
25 50 to 90% by mol.
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3. The rubber composition as claimed in claim 1 or
2, wherein the ethylene/-olefin/non-conjugated polyene
copolymer (A) and/or the -olefin copolymer (C) is
obtained by polymerization using a catalyst having a
5 structure represented by the following formula (I):
4. The rubber composition as claimed in claim 1 or
2, which contains the -olefin copolymer (C) in an amount
10 of 1 to 50 parts by weight, based on 100 parts by weight
of the ethylene/-olefin/non-conjugated polyene copolymer
(A).
15 5. The rubber composition as claimed in claim 1 or
2, wherein the constituent units derived from the nonconjugated
polyene of the component (A) are constituent
units derived from at least one non-conjugated polyene
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selected from the group consisting of 5-ethylidene-2-
norbornene (ENB) and 5-vinyl-2-norbornene (VNB).
6. The rubber composition as claimed in claim 1 or
5 2, further comprising a reinforcing agent.
7. The rubber composition as claimed in claim 6,
wherein the reinforcing agent is carbon black.
10 8. The rubber composition as claimed in claim 7,
wherein the carbon black is contained in an amount of 20
to 200 parts by weight based on 100 parts by weight of
the ethylene/-olefin/non-conjugated polyene copolymer
(A).
15
9. The rubber composition as claimed in claim 1 or
2, which is obtained by alloying the ethylene/-
olefin/non-conjugated polyene copolymer (A) with the
ethylene/C3-C20 -olefin copolymer (C) by means of an
20 extruder in the presence of a solvent.
25 10. The rubber composition as claimed in claim 1 or
2, further comprising paraffinic oil (D), wherein the
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paraffinic oil (D) is contained in an amount of 1 to 200
parts by weight based on 100 parts by weight of the
ethylene/-olefin/non-conjugated polyene copolymer (A).
5 11. An olefin-based thermoplastic elastomer
obtained by treating the rubber composition of claim 1 or
2 and a polypropylene-based resin through dynamic
crosslinking in the presence of a crosslinking agent.
10 12. A crosslinked product obtained by crosslinking
the rubber composition of claim 1 or 2.
13. A foamed product obtained by crosslinking and
foaming the rubber composition of claim 1 or 2.
15
14. A glass run channel, a weatherstrip sponge,
door opening trim or an automobile seal part comprising
the crosslinked product of claim 12 or the foamed product
of claim 13.
20
15. A part for automobiles, a part for ships, a
part for civil engineering and construction, a medical
part, a part for electric/electronic components, a seal
article, a sheet, a shoe, a tire sidewall, a tire tube, a
25 covered electric wire, an electrically insulating part, a
household rubber article, a part for leisure, a coating
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material or an adhesive obtained by the use of the rubber
composition of claim 1 or 2.
16. A hose which is the hose of claim 15 and has a
5 tensile creep value (change of elongation in heating of
the hose from 25°C to 80°C at a rate of 2°C/min under a
constant load of 0.6 MPa using a viscoelasticity tester)
of not more than 2.5%.
10 17. A hose which is the hose of claim 15 and has a
shrinkage ratio (change of length in crosslinking of an
unvulcanized hose) of not more than