DESCRIPTION
SOUND INSULATOR
TECHNICAL FIELD
5 [0001]
The present invention relates to a sound insulator. More
particularly, the present invention relates to a sound insulator
having a light weight and excellent sound insulation properties.
10 BACKGROUND ART
[0002]
In the components and housings of building materials,
electrical and electronic appliances (e.g., personal computers,
office automation equipments, audiovisual equipments and
15 cellular phones), optical instruments, precision instruments,
toys, household/office electric appliances and the like,
particularly in those parts and molded materials that are utilized
in the fields of the transit and transportation industries such
as railway vehicles, automobiles, ships and airplanes, vibration
20 damping and sound insulation properties are demanded in addition
to general material characteristics such as impact resistance,
heat resistance, strength and dimensional stability.
[0003]
Conventionally, materials with high vibration damping
SF-2924 2
properties have been known; however, these
high-vibration-damping materials are not necessarily exhibit
excellent sound insulation. For instance, they can block a
vibration-transmitting sound represented by a low-frequency
5 range, however, are incapable of effectively blocking the sound
in a high-frequency range of 1 to 6 kHz, which is sensitively
detected by human ears.
[0004]
For example, the frequency of wind noise is said to be about
10 2 to 10 kHz. There is a demand for a technology that can block
not only such wind noise but also tire pattern noise and
motor-originated noise. Thus, it is necessary to develop a sound
insulator that is capable of blocking the sound in a high-frequency
range of 1 to 6kHz, which is sensitively detected by human ears,
15 in a well-balanced manner.
[0005]
Patent Documents 4 and 5 disclose shock-absorbing materials
that are characterized by comprising a combination of two or more
polymer materials having different temperature ranges of tan 6
20 determined by dynamic viscoelasticity measurement; however, the
sound insulation properties thereof are not sufficiently
examined.
[0006]
Moreover, in recent years, from the standpoints of reduction
,,
:l
:I
SF-2924 3
in environmental stress and fuel consumption as well as energy
saving, weight reduction is strongly demanded for those parts and
molded materials that are utilized in the fields of the transit
and transportation industries such as railway vehicles,
5 automobiles, ships and airplanes.
[0007]
As a method of improving the sound insulation properties,
Patent Document 1 discloses a technology that improves sound
insulation by incorporating an inorganic material such as a
10 high-specific-gravity metal or metal oxide. The sound insulator
according to this technology exhibits excellent sound insulation
performance; however, since the use of an inorganic material
having a specific gravity of 4.0 or higher inevitably makes the
sound insulator heavy, the demand for weight reduction is not
15 satisfied. In addition, Patent Documents 2 and 3 also disclose
technologies for improving sound insulation by the use of, a
high-specific-gravity filler.
[0008]
Furthermore, as a means for improving the sound insulation
20 properties while achieving weight reduction, sound insulators in
which a plurality of members are combined or a characteristic
feature is imparted to the structure have been examined; however,
since these insulators have a complex structure, there is a problem
that the productivity is not improved due to a reduction in yield,
SF-2924 4
a reduction in production rate and the like.
[0009]
That is, it is strongly desired to develop a technology and
a material that are capable of achieving both a reduction in weight
5 and an improvement in sound insulation properties without relying
on a complex structure.
10
15
20
PRIOR ART REFERENCES
PATENT
[0010]
[0011]
DOCUMENTS
[Patent Document 1] JP-A-S58-90700
[Patent Document 2] JP-A-2001-146534
[Patent Document 3] JP-A-2001-002866
[Patent Document 4] wo 2013/191222
[Patent Document 5] JP-A-2012-162668
SUMMARY OF THE INVENTION
PROBLEMS TO BE SOLVED BY THE INVENTION
An object of the present invention is to provide a sound
insulator which achieves both a reduction in weight and an
improvement in sound insulation properties without relying on a
complex structure.
SF-2924 5
TECHNICAL SOLUTION
[0012]
The present inventors intensively studied in order to solve
the above-described problems and consequently discovered that a
5 light-weight sound insulator having excellent sound insulation
properties can be obtained by using a combination of materials
each having a peak of loss tangent (tan o), which is determined
by dynamic viscoelasticity measurement, in a specific temperature
range. Further, as a result of intensively studying sound
10 insulation, it was discovered that a polymer material having a
peak of loss tangent (tan o), which is determined by dynamic
viscoelasticity measurement, in a temperature range of 0 °C to 60 °C
exhibits excellent sound insulation at 1 to 4 kHz and that a polymer
material having a peak of loss tangent (tan o), which is determined
15 by dynamic viscoelasticity measurement, in a temperature range
of -60°C to lower than 0°C exhibits excellent sound insulation
at 4 to 6 kHz. By blending these polymer materials at an optimum
ratio and further cross-linking them depending on the case, a
rubber composition and a cross-linked product thereof, which are
20 capable of blocking the sound over a range of 1 to 6 kHz in a
well-balanced manner, can be obtained.
[0013]
That is, the present invention provides a sound insulator
which comprises: a flexible material (A) having a peak of loss
.·
'
~j
.ii,
i:
.~,I
SF-2924 6
tangent (tan o), which is determined by dynamic viscoelasticity
measurement, in a temperature range of -60°C to lower than 0°C;
and a resin (B) having a peak of loss tangent (tan o), which is
determined by dynamic viscoelasticity measurement, in a
5 temperature range of 0°C to 60°C, the sound insulator comprising
the resin (B) at a ratio of 1 to 50 parts by mass with respect
to 100 parts by mass of the flexible material (A) .
[0014]
In the sound insulator, it is preferred that the flexible
10 material (A) comprise at least one selected from ethylene-based
rubbers, natural rubbers and diene-based rubbers.
[0015]
In the sound insulator, it is preferred that the flexible
material (A) comprise an ethylene·a-olefin·non-conjugated
15 polyene copolymer (a) .
[0016]
It is preferred that the ethylene ·a-olefin ·non-conjugated
polyene copolymer (a) comprises a structural unit derived from
ethylene in an amount of 40 to 72% by mass and a structural unit
20 derived from a non-conjugated polyene in an amount of 2 to 15%
by mass.
[0017]
In the sound insulator, it is preferred that the resin (B)
comprises at least one selected from aromatic polymers,
5
SF-2924 7
4-methyl-1-pentene·a-olefin copolymer (b), polyvinyl acetates,
polyesters, polyurethanes, poly (meth) acrylates, epoxy resins and
polyamides.
[0018]
In the sound insulator, it is preferred that the resin (B)
comprise a 4-methyl-1-pentene·a-olefin copolymer (b-1) which
contains 16 to 95% by mol of a structural unit (i) derived from
4-methyl-1-pentene, 5 to 84% by mol of a structural unit (ii)
derived from at least one a-olefin selected from a-ole fins having
10 2 to 20 carbon atoms excluding 4-methyl-1-pentene and 0 to 10%
15
20
by mol of a structural unit (iii) derived from a non-conjugated
polyene (with a proviso that the total amount of the structural
units (i), (ii) and (iii) is 100% by mol).
[0019]
Preferred examples of the' sound insulator include sound
insulators that are·obtained by cross~linking a composition
comprising the flexible material (A) and the resin (B) using a
vulcanizing agent.
[0020]
It is preferred that at least a portion of the sound
insulator is a foamed article.
[0021]
Further, the present invention can also provide a sealing
material for automobiles, a sealing material for construction,
5
SF-2924 8
a sealing material for railway vehicles, a sealing material for
ships, a sealing material for airplanes and the like, all of which
comprise the above-described sound insulator.
ADVANTAGEOUS EFFECTS OF INVENTION
[0022]
The sound insulator of the present invention is a material
which realizes excellent sound insulation properties without
relying on a complex shape or an increase in weight.
10 [0023]
The sound insulator of the present invention is effective
as a component or housing of building materials (e.g., floor
linings, walls and ceiling materials) , electrical and electronic
appliances (e.g., personal computers, office automation
15 equipments, audiovisual equipments and cellular phones) , optical
instruments, precision instruments, toys, household/office
electric appliances and the like, and thus has an extremely high
utility value as a component or molded material particularly in
the fields of the transit and transportation industries such as
20 railway vehicles, automobiles, ships and airplanes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024]
[Fig. 1] Fig. l(A) is a graph showing the relationship
SF-2924 9
between the specimen weight and the average transmission loss at
a frequency of 1 to 4 kHz for the sound insulators of Example 1
and Comparative Examples 1 to 6. Fig. l(B) is a graph showing
the relationship between the specimen weight and the average
5 transmission loss at a frequency of 4 to 6 kHz for the sound
insulators of Example 1 and Comparative Examples 1 to 6.
[Fig. 2] Fig. 2(A) is a graph showing the relationship
between the specimen weight and the average transmission loss at
a frequency of 1 to 4 kHz for the sound insulators of Examples
10 11 to 16 and Comparative Examples 16 to 20. Fig. 2 (B) is a graph
showing the relationship between the specimen weight and the
average transmission loss in a frequency range of 4 to 6 kHz for
the sound insulators of Examples 11 to 16 and Comparative Examples
16 to 20.
15
MODE: FOR CARRYING OUT THE INVENTION
[DD25]
The present invention is a sound insulator which comprises:
a flexible material (A) having a peak of loss tangent (tan o),
20 which is determined by dynamic viscoelasticity measurement, in
a temperature range of -6D°C to lower than DoC; and a resin (B)
having a peak of loss tangent (tan o), which is determined by
dynamic viscoelasticity measurement, in a temperature range of
D°C to 6D°C, the sound insulator comprising the resin (B) at a
SF-2924 10
ratio of 1 to 50 parts by mass with respect to 100 parts by mass
of the flexible material (A) .
[0026]
First, the loss tangent (tan 6) determined by dynamic
5 viscoelasticity measurement will be described. For a subject
material, dynamic viscoelasticity measurement is performed while
continuously changing the atmospheric temperature, thereby
measuring the storage elastic modulus G' (Pa) and the loss elastic
modulus G"(Pa) to determine the loss tangent (tan 6), which is
10 represented by G" /G' . According to the relationship between the
temperature and the loss tangent (tan 6), the loss tangent (tan
o) generally shows a peak at a specific temperature. The
temperature at which the peak appears is generally referred to
as "glass transition temperature" (hereinafter, also indicated
15 as "tan 6 - Tg". The temperature at which the peak of loss tangent
(tan 6) appears can be determined based on the dynamic
viscoelasticity measurement described below in Examples.
[0027]
The flexible material (A) contained in the sound insulator
20 of the present invention has a peak of loss tangent (tan 6) in
a temperature range of -60°C to lower than 0°C. The resin (B)
contained in the sound insulator of the present invention has a
peak of loss tangent (tan 6) in a temperature range of 0°C to 60°C.
The sound insulator of the present invention comprises these
SF-2924 11
flexible material (A) and resin (B) at a ratio of 1 to 50 parts
by mass of the resin (B) per 100 parts by mass of the flexible
material (A) . The sound insulator of the present invention that
satisfies these conditions has excellent sound insulation
5 properties. The sound insulator of the present invention can
realize a reduction in weight because it is not required to contain
a filler having a high specific gravity. In addition, the sound
insulator of the present invention is not required to be processed
into a complex structure because there is no need to use a
10 combination of plural members therein or to impart a
characteristic feature to the structure. The reason why the sound
insulator of the present invention can realize excellent sound
insulation properties by satisfying the above-described
conditions is believed to be because the sound insulator is capable
15 of effectively blocking the sound over the entire high-frequency
range of 1 to 6 kHz, which is sensitively detected by human ears,
by containing a plurality of materials having a peak of loss
tangent (tan iS) in different temperature ranges of -60°C to lower
than 0°C and 0°C to 60°C at a prescribed ratio.
20 [ 0 02 8]
From the standpoint of improving the sound insulation
properties, the flexible material (A) has a peak of loss tangent
(tan iS) in a temperature range of preferably -55 to -5°C, more
preferably -50 to -l0°C, and the resin (B) has a peak of loss
SF-2924 12
tangent (tan 6) in a temperature range of preferably 5 to 55°C,
more preferably 10 to 50°C. Further, from the standpoint of
improving the sound insulation properties, the sound insulator
of the present invention contains the resin (B) at a ratio of
5 preferably 5 to 45 parts by mass, more preferably 10 to 40 parts
by mass, with respect to 100 parts by mass of the flexible material
(A) .
[0029]
The type of the flexible material (A) is not particularly
10 restricted because excellent sound insulation properties can be
attained as described above as long as the flexible material (A)
is a material that has a peak of loss tangent (tan 6) in a
temperature range of -60°C to lower than 0°C. The flexible
material (A) can be, for example, a material containing an
15 ethylene-based rubber, a natural rubber, a diene-based rubber
and/or the like. The flexible material (A) may also be a mixture
of these materials.
[ 0030 l
Examples of the diene-based rubber include isoprene rubber
20 (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR),
chloroprene rubber (CR), acrylonitrile-butadiene rubber (NBR)
and butyl rubber (IIR).
[0031]
Examples of the ethylene-based rubber include
SF-2924 13
ethylene·a-olefin copolymers (EPM) and
ethylene·a-olefin·non-conjugated polyene copolymers (EPDM).
[0032]
Examples of the ethylene·a-olefin copolymers include
5 copolymers of ethylene and an a-olefin having 3 to 20 carbon atoms.
Examples of the a-olefin include propylene,
butene-1,4-methylpentene-1, hexene-1, heptene-1, octene-1,
nonene-1, decene-1, undecene-1, dodecene-1, tridecene-1,
tetradecene-1, pentadecene-1, hexadecene-1, heptadecene-1,
10 nonadecene-1, eicosene-1, 9-methyl-decene-1,
11-methyl-dodecene-1 and 12-ethyl-tetradecene-1. These
a-olefins may be used individually, or two or more thereof may
be used in combination.
[0033]
15 The a-olefins in the above-described
ethylene ·a-olefin ·non-conjugated polyene copolymers are the same
as those in the ethylene;ci-olefin copolymers.
[0034]
The non-conjugated polyenes in the
20 ethylene·a-olefin·non-conjugated polyene copolymers is, for
example, a non-conjugated polyene having 5 to 20 carbon atoms,
preferably 5 to 10 carbon atoms, and specific examples thereof
include 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene,
1,4-octadiene, 1,5-octadiene, 1,6-octadiene, 1,7-octadiene,
:i
.,
f!
'i
q
i! ::
'i
SF-2924 14
2-methy1-1,5-hexadiene, 6-methyl-1,5-heptadiene,
7-methyl-1,6-octadiene, 4-ethylidene-8-methyl-1,7-nonadiene,
4,8-dimethyl-1,4,8-decatriene, dicyclopentadiene,
cyclohexadiene, dicyclooctadiene, methylene norbornene, 5-vinyl
5 norbornene, 5-ethylidene-2-norbornene,
5-methylene-2-norbornene, 5-vinylidene-2-norbornene,
5-isopropylidene-2-norbornene,
6-ch1oromethyl-5-isopropenyl-2-norbornene,
2,3-diisopropylidene-5-norbornene,
10 2-ethylidene-3-isopropylidene-5-norobornene, and
2-propenyl-2,2-norbornadiene.
[0035]
From the standpoints of thermal aging resistance, weather
resistance and ozone resistance, it is particularly preferred
15 that the flexible material (A) contain an
ethylene ·a-:-.olefin ·non-conjugated polyene copolymer (a). The
content of the ethylene·a-olefin·non-conjugated polyene
copolymer (a) in the flexible material (A) is preferably 50 to
100% by mass, more preferably 70 to 100% by mass.
20 [0036]
In the ethylene ·a-olefin ·non-conjugated polyene copolymer
(a), from the standpoint of flexibility, the content of a
structural unit derived from ethylene is preferably 40 to 72% by
mass, more preferably 42 to 66% by mass, still more preferably
SF-2924 15
44 to 62% by mass, and the content of a structural unit derived
from a non-conjugated polyene is preferably 2 to 15% by mass, more
preferably 5 to 14% by mass, still more preferably 7 to 12% by
mass.
5 [0037]
In the ethylene ·ex-olefin ·non-conjugated polyene copolymer
(a), among the above-described ex-olefins, those having 3 to 10
carbon atoms are preferred and, for example, propylene, 1-butene,
1-hexene and 1-octene are particularly preferred.
10 [0038]
In the ethylene ·ex-olefin ·non-conjugated polyene copolymer
(a), among the above-described non-conjugated polyenes, for
example, dicyclopentadiene, 5-vinylidene-2-norbornene and
5-ethylidene-2-norbornene are preferred.
15 [0039]
Further, it iE) preferred that the content of a crystallized
polyolefin in the flexible material (A) be less than 10% by mass.
[0040]
The type of the resin (B) is not particularly restricted
20 because excellent sound insulation properties can be attained as
described above as long as the resin (B) is a material that has
a peak of loss tangent (tan 6) in a temperature range of 0°C to
60°C. Examples of the resin (B) include aromatic polymers,
4-methyl-1-pentene·ex-olefin copolymer (b), polyvinyl acetates,
--------------- -----------
SF-2924 16
polyesters, polyurethanes, poly (meth) acrylates, epoxy resins and
polyamides. The resin (B) may also be a mixture of these materials.
From the standpoints of weather resistance and ozone resistance,
it is particularly preferred that the resin (B) contain a
5 4-methyl-1-pentene ·a-olefin copolymer (b).
[0041]
Examples of the aromatic polymers include polymers of an
aromatic vinyl monomer (s), such as styrene and alkylstyrenes; and
copolymers of an aromatic vinyl monomer and an olefin monomer.
10 [0042]
The a-olefin in the 4-methyl-1-pentene·a-olefin copolymer
(b) is, for example, an a-olefin having 2 to 20 carbon atoms and,
excluding 4-methyl-1-pentene, examples thereof include linear or
branched a-olefins, cyclic olefins, aromatic vinyl compounds,
15 conjugated dienes, and functionalized vinyl compounds. It is
defined here that non-conjugated polyenes are not included in the
a-olefin of the 4-methyl-1-pentene·a-olefin copolymer.
[0043]
The linear a-olefins are, for example, those having 2 to
20 20 carbon atoms, preferably 2 to 15 carbon atoms, more preferably
2 to 10 carbon atoms, and specific examples thereof include
ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene,
1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene,
1-octadecene, and 1-eicosene. Thereamong, ethylene, propylene,
,,
!,I,
'i
li
:1
:I
'I
I
"!
SF-2924 17
1-butene, 1-pentene, 1-hexene and 1-octene are preferred.
[0044]
The branched a-olefins are, for example, those having
preferably 5 to 20 carbon atoms, more preferably 5 to 15 carbon
5 atoms, and specific examples thereof include 3-methyl-1-butene,
3-methyl-1-pentene, 3-ethyl-1-pentene, 4,4-dimethyl-1-pentene,
4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4-ethyl-1-hexene,
and 3-ethyl-1-hexene.
[0045]
10 The cyclic olefins are, for example, those having 3 to 20
carbon atoms, more preferably 5 to 15 carbon atoms, and specific
examples thereof include cyclopentene, cyclohexene, cycloheptene,
norbornene, 5-methyl-2-norbornene, tetracyclododecene, and
vinylcyclohexane.
15 [0046]
Examples of the aromatic vinyl compounds include styrene
and mono- or a poly-alkylstyrenes, such as a-methylstyrene,
o-methylstyrene, m-methylstyrene, p-methylstyrene,
o,p-dimethylstyrene, o-ethylstyrene, m-ethylstyrene and
20 p-ethylstyrene.
[0047]
The conjugated dienes are, for example, those having 4 to
20 carbon atoms, preferably 4 to 10 carbon atoms, and specific
examples thereof include 1,3-butadiene, isoprene, chloroprene,
!
SF-2924 18
1,3-pentadiene, 2,3-dimethy1 butadiene,
4-methy1-1,3-pentadiene, 1,3-hexadiene, and 1,3-octadiene.
[0048]
Examples of the functionalized vinyl compounds include
5 hydroxyl group-containing olefins; halogenated olefins;
unsaturated carboxylic acids, such as (meth)acrylic acid,
propionic acid, 3-butenoic acid, 4-pentenoic acid, 5-hexenoic
acid, 6-heptenoic acid, 7-octenoic acid, 8-nonenoic acid,
9-decenoic acid and 10-undecenoic acid; unsaturated amines, such
10 as allylamine, 5-hexeneamine and 6-hepteneamine;
(2,7-octadienyl) succinic anhydride, pentapropenyl succinic
anhydride, unsaturated carboxylic acid anhydrides such as those
obtained from the above-described unsaturated carboxylic acids;
unsaturated carboxylic halides, such as halides obtained from the
15 above-described unsaturated carboxylic acids; unsaturated epoxy
compounds, such as 4-epoxy-1-butene, 5-epoxy-1-pentene,
6-epoxy-1-hexene, 7-epoxy-l-heptene, 8-epoxy-1-octene,
9-epoxy-1-nonene, 10-epoxy-1-decene and 11-epoxy-1-undecene;
and ethylenically unsaturated silane compounds, such as
20 vinyltriethoxysi1ane, vinyltrimethoxysilane, 3-acryloxypropyl
trimethoxysilane, y-glycidoxypropyltripyl trimethoxysilane,
r-aminopropyl triethoxysilane and y-methacryloxypropyl
trimethoxysilane.
[0049]
SF-2924 19
The hydroxyl group-containing olefins are not particularly
restricted as long as they are hydroxyl group-containing olefin
compounds, and examples thereof include hydroxyl
group-terminated olefin compounds. Examples of the hydroxyl
5 group-terminated olefin compounds include linear hydroxylated
a-olefins having 2 to 20, preferably 2 to 15 carbon atoms, such
as vinyl alcohols, allyl alcohols, hydroxylated 1-butene,
hydroxylated 1-pentene, hydroxylated 1-hexene, hydroxylated
1-octene, hydroxylated 1-decene, hydroxylated 1-undecene,
10 hydroxylated 1-dodecene, hydroxylated 1-tetradecene,
hydroxylated 1-hexadecene, hydroxylated 1-octadecene and
hydroxylated 1-eicosene; and branched hydroxylated a-olefins
having preferably 5 to 20 carbon atoms, more preferably 5 to 15
carbon atoms, such as hydroxylated 3-methyl-1-butene,
15 hydroxylated 3-methyl-1-pentene, hydroxylated
4-methyl-1-pentene, hydroxylated 3-ethyl-1-pentene,
hydroxylated 4,4-dimethyl-1-pentene, hydroxylated
4-methyl-1-hexene, hydroxylated 4,4-dimethyl-1-hexene,
hydroxylated 4-ethyl-1-hexene and hydroxylated
20 3-ethyl-1-hexene.
[0050]
The halogenated olefins are, for example, halogenated
a-olefins having an atom belonging to Group 17 of the periodic
table such as chlorine, bromine or iodine, and specific examples
tj
il
II
!1
ii
[!
ii
-----------------
SF-2924 20
thereof include linear halogenated a-olefins having 2 to 20 carbon
atoms, preferably 2 to 15 carbon atoms, such as halogenated vinyl,
halogenated 1-butene, halogenated 1-pentene, halogenated
1-hexene, halogenated 1-octene, halogenated 1-decene,
5 halogenated 1-dodecene, halogenated 1-undecene, halogenated
1-tetradecene, halogenated 1-hexadecene, halogenated
1-octadecene and halogenated 1-eicosene; and branched
halogenated a-olefi.ns having preferably 5 to 20 carbon atoms, more
preferably 5 to 15 carbon atoms, such as halogenated
10 3-methyl-1-butene, halogenated 4-methyl-1-pentene, halogenated
3-methyl-1-pentene, halogenated 3-ethyl-1-pentene, halogenated
4,4-dimethyl-1-pentene, halogenated 4-methyl-1-hexene,
halogenated 4,4-dimethyl-1-hexene, halogenated
4-ethyl-1-hexene and halogenated 3-ethyl-1-hexene.
15 [0051]
In the 4-methyl-1-pentene·a-olefin copolymer (b), the
above-described a-ole fins may be used individually, or two or more
thereof may be used in combination.
[0052]
20 As the a-olefin in the 4-methyl-1-pentene·a-olefin
copolymer (b), ethylene, propylene, 1-butene, 1-pentene,
1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 1-octene,
1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene,
1-octadecene, 1-eicosene, norbornene, 5-methyl-2-norbornene,
SF-2924 21
tetracyclododecene and hydroxy1ated-1-undecene are particularly
suitable. Further, from the standpoints of flexibility, stress
absorption, stress relaxation and the like, linear a-olefins
having 2 to 10 carbon atoms are preferred, and ethylene, propylene,
5 1-butene, 1-pentene, 1-hexene and 1-octene are more preferred.
Thereamong, from the standpoint of attaining high stress
absorption and polyolefin-modifying property, ethylene and
propylene are preferred, and propylene is particularly preferred.
[0053]
10 As required, the 4-methyl-1-pentene ·a-olefin copolymer (b)
may also contain a structural unit derived from a non-conjugated
polyene. The non-conjugated polyene is the same as the one in
the above-described ethylene·a-olefin·non-conjugated polyene
copolymer (a) .
15 [0054]
The 4-methyl-1-pentene·a-olefin copolymer (b) .may also
contain other copolymerizable component within a range that does
not adversely affect the object of the present invention.
[0055]
20 As the 4-methyl-1-pentene·a-olefin copolymer (b), a
4-methyl-1-pentene·a-olefin copolymer (b-1) which contains a
structural unit (i) derived from 4-methyl-1-pentene, a structural
unit (ii) derived from at least one a-olefin selected from
a-olefins having 2 to 20 carbon atoms excluding
SF-2924 22
4-methyl-1-pentene and, optionally, a structural unit (iii)
derived from a non-conjugated polyene at the following ratios is
preferred. That is, in the 4-methyl-1-pentene·a-olefin
copolymer (b-1) , taking the total amount of the structural units
5 (i), (ii) and (iii) as 100% by mol, the structural units (i), (ii)
and (iii) are contained at ratios of 16 to 95% by mol, 5 to 84%
by mol and 0 to 10% by mol, preferably 26 to 90% by mol, 10 to
74% by mol and 0 to 7% by mol, still more preferably 61 to 85%
by mol, 15 to 39% by mol and 0 to 5% by mol, respectively.
10 [0056]
In addition to the above-described flexible material (A)
and resin (B), the sound insulator of the present invention may
also contain a softener, a reinforcing agent, a filler, a
processing aid, an activator, a moisture absorbent and the like
15 within a range that does not adversely affect the object of the
present invention.
[0057]
The softener can be selected as appropriate in accordance
with the use thereof, and a softener may be used individually,
20 or two or more thereof may be used in combination. Specific
examples of the softener include petroleum-based softeners, for
example, process oils such as paraffin oils (e.g., "DIANA PROCESS
OIL PS-430" (trade name, manufactured by Idemitsu Kosan Co.,
Ltd.)), lubricating oils, liquid paraffin, petroleum asphalt and
SF-2924 23
vaseline; coal tar-based softeners such as coal tar and coal tar
pitch; fatty oil-based softeners such as castor oil, linseed oil,
rapeseed oil, soybean oil and coconut oil; waxes such as beeswax,
carnauba wax and lanolin; fatty acids and salts thereof, such as
5 ricinoleic acid, palmitic acid, stearic acid, barium stearate,
calcium stearate and zinc laurate; naphthenic acid, pine oil,
rosin, and derivatives thereof; synthetic polymer materials such
as terpene resins, petroleum resins, atactic polypropylenes and
coumarone-indene resins; ester-based softeners such as dioctyl
10 phthalate, dioctyl adipate and dioctyl sebacate; and other
softeners such as microcrystalline waxes, liquid polybutadienes,
modified liquid polybutadienes, liquid thiokols,
hydrocarbon-based synthetic lubricating oils, tall oil and rubber
substitutes (factice). Thereamong, petroleum-based softeners
15 are preferred, and process oils; especially paraffin oils, are
particularly preferreq.
[0058]
The softener is incorporated in an amount of usually 5 to
150 parts by mass, preferably 10 to 120 parts by mass, more
20 preferably 20 to 100 parts by mass, with respect to 100 parts by
mass of the flexible material (A) .
[0059]
Specific examples of a reinforcing agent that can be used
include commercially available carbon blacks such as "Asahi #55G"
SF-2924 24
and "Asahi #50HG" (trade name: manufactured by Asahi Carbon Co.,
Ltd.), and "SEAST (trade name)" Series: SRF, GPF, FEF, MAF, HAF,
ISAF, SAF, FT and MT (manufactured by Tokai Carbon Co., Ltd.);
these carbon blacks that are surface-treated with a
5 silane-coupling agent or the like; silica; activated calcium
carbonate; finely powdered talc; and finely powdered silicic acid.
Thereamong, carbon blacks "Asahi #55G", "Asahi #50HG" and "SEAST
HAF" are preferred.
10
[0060]
As the filler, light calcium carbonates, heavy calcium
carbonates, talc, clays and the like can be used. Thereamong,
heavy calcium carbonates are preferred. As a heavy calcium
carbonate, for example, commercially available "WHITON SB" (trade
name: manufactured by Shiraishi Calcium Kaisha, Ltd.) can be used.
15 [0061]
The reinforcing agent and the filler are each incorporated
in an amount of usually 30 to 300 parts by mass, preferably 50
to 250 parts by mass, still more preferably 70 to 230 parts by
mass, with respect to 100 parts by mass of the flexible material
20 (A) .
[0062]
As the processing aid, substances that are generally
incorporated as a processing aid into rubbers can be widely used.
Specific examples thereof include ricinoleic acid, stearic acid,
SF-2924 25
palmitic acid, lauric acid, barium stearate, zinc stearate,
calcium stearate and esters. Thereamong, stearic acid is
preferred. The processing aid is incorporated as appropriate in
an amount of usually 10 parts by mass or less, preferably 8. 0 parts
5 by mass or less, still more preferably 5. 0 parts by mass or less,
with respect to 100 parts by mass of the flexible material (A).
[0063]
The activator can be selected as appropriate in accordance
with the use thereof, and an activator may be used individually,
10 or two or more thereof may be used in combination. Specific
examples of the activator include amines such as di-n-butylamine,
dicyclohexylamine, monoethanolamine, "ACTING B" (trade name:
manufactured by Yoshitomi Pharmaceutical Industries, Ltd.) and
"ACTING SL" (trade name: manufactured by Yoshi tomi Pharmaceutical
15 Industries, Ltd.); activators such as diethylene glycol,
polyethylene glycols (e.g., "PEG#4000" (manufactured by Lion
Corporation)), lecithin, triallyl trimellitate, and zinc
compounds of aliphatic and aromatic carboxylic acids (e.g.,
"STRUKTOL ACTIVATOR 73", "STRUKTOL IB531" and "STRUKTOL FA541"
20 (trade names: manufactured by Schill & Seilacher GmbH)); zinc
peroxide-modified activators such as "ZEONET ZP" (trade name:
manufactured by ZEON Corporation); octadecyltrimethylammonium
bromide; synthetic hydrotalcites; and special quaternary
ammonium compounds (e.g., "ARQUAD 2HF" (trade name: manufactured
SF-2924 26
by LION AKZO Co., Ltd.) ) . Thereamong, polyethylene glycols (e.g. ,
"PEG#4000" (manufactured by Lion Corporation)) and "ARQUAD 2HF"
are preferred. The activator is incorporated in an amount of
usually 0. 2 to 10 parts by mass, preferably 0. 3 to 5 parts by mass,
5 still more preferably 0. 5 to 4 parts by mass, with respect to 100
parts by mass of the flexible material (A) .
[0064]
The moisture absorbent can be selected as appropriate in
accordance with the use thereof, and a moisture absorbent may be
10 used individually, or two or more thereof may be used in
combination. Specific examples of the moisture absorbent include
calcium oxide, silica gel, sodium sulfate, molecular sieve,
zeolite and white carbon. Thereamong, calcium oxide is preferred.
The moisture absorbent is incorporated in an amount of usually
15 0. 5 to 15 parts by mass, preferably 1. 0 to 12 parts by mass, still
more preferably 1. 0 to 10 parts by mass, with respect to 100 parts
by mass of the flexible material (A).
[0065]
The sound insulator of the present invention can be obtained
20 by kneading the above-described components. The shape of the
sound insulator of the present invention is not particularly
restricted. For example, the sound insulator of the present
invention is molded into a sheet form by a sheet molding method
such as calender rolling or T-die extrusion. By molding the sound
SF-2924 27
insulator of the present invention into a sheet form, the sound
insulator of the present invention can be used as a sound
insulation sheet. Further, by compression-molding the resulting
sheet using a die that yields a molded article of a prescribed
5 shape, a sound insulator of a desired shape can be obtained.
[0066]
In cases where the sound insulator of the present invention
contains cross-linkable components such as an
ethylene·a-olefin·non-conjugated polyene copolymer, these
10 components may be cross-linked as well. For the cross-linking,
a vulcanizing agent is added to the cross-linkable components and
the resultant is kneaded. That is, the sound insulator of the
present invention can also be obtained by cross-linking a
composition that comprises the flexible material (A) and the resin
15 (B) using a vulcanizing agent.
[0067]
As the vulcanizing agent (cross-linking agent), for example,
i
ii
sulfur compounds, organic peroxides, phenol resins and oxime
~~
~ 1 compounds can be used.
II
il ! 20 [0068]
(I
.:<,i
! Examples of the sulfur compounds include sulfur, sulfur
chloride, sulfur dichloride, morpholine disulfide, alkylphenol
disulfide, tetramethylthiuram disulfide and selenium
dithiocarbamate. Thereamong, sulfur and tetramethylthiuram
SF-2924 28
disulfide are preferred. Such sulfur compound is incorporated
in an amount of usually 0.3 to 10 parts by mass, preferably 0.5
to 5.0 parts by mass, still more preferably 0.7 to 4.0 parts by
mass, with respect to 100 parts by mass of the flexible material
5 (A) •
[0069]
Examples of the organic peroxides include dicumyl peroxide,
2,5-dimethyl-2,5-di(t-butylperoxy)hexane,
2,5-dimethyl-2,5-di(benzoylperoxy)hexane,
10 2, 5-diethyl-2, 5-di ( t-butylperoxy) hexyne-3, di- t-butyl peroxide,
di-t-butylperoxy-3,3,5-trimethylcyclohexane, and
t-dibutylhydroperoxide. Thereamong, dicumyl peroxide,
di-t-butyl peroxide and
di-t-butylperoxy-3,3,5-trimethylcyclohexane are preferred.
15 Such organic peroxide is incorporated in an amount of usually 0. 001
to 0:05 mol, preferably. 0. 002 to 0. 02 mol, still more preferably
0. 005 to 0. 015 mol, with respect to 100 g of the flexible material
20
(A) •
[0070]
In cases where a sulfur compound is used as the vulcanizing
agent, it is preferred that a vulcanization accelerator be used
in combination. Examples of the vulcanization accelerator
include thiazole-based vulcanization accelerators, such as
N-cyclohexyl-2-benzothiazole sulfenamide,
SF-2924 29
N-oxydiethylene-2-benzothiazole sulfenamide,
N,N'-diisopropyl-2-benzothiazole sulfenamide,
2-mercaptobenzothiazole (e.g., "SANCELER M" (trade name:
manufactured by Sanshin Chemical Industry Co., Ltd.)),
5 2-(4-morpholinodithio)benzothiazole (e.g., "NOCCELER MDB-P"
(trade name: manufactured by Sanshin Chemical Industry Co.,
Ltd.)), 2-(2,4-dinitrophenyl)mercaptobenzothiazole,
2-(2,6-diethyl-4-morpholinothio)benzothiazole and
dibenzothiazyl disulfide; guanidine-based vulcanization
10 accelerators, such as diphenylguanidine, triphenylguanidine and
di-ortho-tolylguanidine; aldehyde amine-based vulcanization
accelerators, such as acetaldehyde-aniline condensate and
butylaldehyde-aniline condensate; imidazoline-based
vulcanization accelerators, such as 2-mercaptoimidazoline;
15 thiourea-based vulcanization accelerators, such as
diethylthiourea and dibutylthiourea; thiuram-based
vulcanization accelerators, such as tetramethylthiuram
monosulfide and tetramethylthiuram disulfide; dithioate-based
vulcanization accelerators, such as zinc dimethyldithiocarbamate,
20 zinc diethyldi thiocarbamate, zinc dibutyldi thiocarbamate (e.g.,
"SANCELER PZ" (trade name: manufactured by Sanshin Chemical
Industry Co., Ltd.) and "SANCELER BZ" (trade name: manufactured
by Sanshin Chemical Industry Co., Ltd.)), and tellurium
diethyldithiocarbamate; thiourea-based vulcanization
SF-2924 30
accelerators, such as ethylene thiourea (e.g.,"SANCELER BUR"
(trade name: manufactured by San shin Chemical Industry Co., Ltd.)
and "SANCELER 22-C" (trade name: manufactured by San shin Chemical
Industry Co., Ltd.)), and N,N'-diethylthiourea; xanthate-based
5 vulcanization accelerators, such as zinc dibutylxanthate; and
zinc white (e.g., zinc oxide such as "META-Zl02" (trade name:
manufactured by Inoue Calcium Corporation)).
[0071]
These vulcanization accelerators are incorporated in an
10 amount of usually 0 .1 to 20 parts by mass, preferably 0. 2 to 15
parts by mass, still more preferably 0. 5 to 10 parts by mass, with
respect to 100 parts by mass of the flexible material (A) .
[0072]
In cases where vulcanization is performed, a vulcanization
15 aid may also be used. The vulcanization aid can be selected as
appropriate in accordance with the use thereof, and a
vulcanization aid may be used individually, or two or more thereof
may be used in combination. Specific examples of the
vulcanization aid include magnesium oxide and zinc white (e.g.,
20 zinc oxide such as "META-Zl02" (trade name: manufactured by Inoue
Calcium Corporation) . The vulcanization aid is usually
incorporated in an amount of 1 to 20 parts by mass with respect
to 100 parts by mass of the flexible material (A) . Other examples
of the vulcanization aid include quinone dioxime-based
SF-2924 31
vulcanization aids such as p-quinone dioxime; acrylic
vulcanization aids, such as ethylene glycol dimethacrylate and
trimethylolpropane trimethacrylate; allyl vulcanization aids,
such as diallyl phthalate and triallyl isocyanurate;
5 maleimide-based vulcanization aids; and divinylbenzene.
[0073]
The sound insulator of the present invention may be entirely
or partially a foamed article. The foamed article may be a
vulcanized foamed article. By constituting at least a portion
10 of the sound insulator of the present invention with a foamed
article, for example, the sound insulator can be effectively used
as a sponge-form seal product for automobiles, particularly as
a weather strip.
15
[0074]
In cases where the sound insulator of the present invention
is made into a foamed article, the above-described components-are
foamed with an addition of a foaming agent thereto. Examples of
the foaming agent include inorganic foaming agents, such as sodium
bicarbonate and sodium carbonate; and organic foaming agents,
20 such as nitroso compounds (e.g., N,N'-dinitrosopentamethylene
tetramine and N,N'-dinitrosoterephthalamide), azo compounds
(e.g., azodicarbonamideandazobis-isobutyronitrile), hydrazide
compounds (e.g., benzenesulfonylhydrazide and
4,4'-oxybis(benzenesulfonylhydrazide)) and azide compounds
SF-2924 32
(e.g., calcium azide and 4,4'-diphenyldisulfonyl azide).
[0075]
The foaming agent is incorporated in an amount of usually
3 to 30 parts by mass, preferably 4 to 20 parts by mass, with respect
5 to 100 parts by mass of the flexible material (A) . As the foaming
agent, for example, VINYFOR AC#3M (trade name: azodicarbonamide
manufactured by Eiwa Chemical Ind. Co., Ltd. (abbreviation:
ADCA)), VINYFOR AC#3C-K2 azodicarbonamide (trade name:
azodicarbonamide manufactured by Eiwa Chemical Ind. Co., Ltd.
10 (abbreviation: ADCA)), CELLMIC C-2 (trade name: azodicarbonamide
manufactured by Sankyo Kasei Co., Ltd. (abbreviation: ADCA)) and
NEOCELLBORN N#lOOOM (trade name:
4,4'-oxybis(benzenesulfonylhydrazide) manufactured by Eiwa
Chemical Ind. Co., Ltd. (abbreviation: OBSH)), all of which are
15 commercially available, can be used.
[0076]
Further, a foaming aid may also be used along with the
foaming agent. Examples of the foaming aid include organic acids,
;1::
:i such as salicylic acid, phthalic acid, stearic acid, oxalic acid
~~ il 20
"
and citric acid, and salts thereof; and urea and derivatives
i"l
i:i u thereof. The foaming aid is incorporated in an amount of usually
0.1 to 5 parts by mass, preferably 0.3 to 4 parts by mass, with
respect to 100 parts by mass of the flexible material (A) . As
the foaming aid, for example, CELLPASTE K5 (trade name: urea
SF-2924 33
manufactured by Eiwa Chemical Ind. Co., Ltd.) and FE-507 (trade
name: sodium bicarbonate manufactured by Eiwa Chemical Ind. Co.,
Ltd.), which are commercially available, can be used.
[0077]
5 In cases where the sound insulator of the present invention
is a vulcanized foamed article, a composition containing the
above-described components, vulcanizing agent, foaming agent and
the like are vulcanized and foamed. Examples of a method for the
vulcanization and foaming include a method in which the
10 composition is extruded and molded into a tube form using an
extruder fitted to a tube-shaped die. Simultaneously with the
molding, the resulting molded article can be introduced to a
vulcanization chamber and heated at, for example, 230°C for 5
minutes to perform cross-linking and foaming, thereby a
15 tube-shaped foamed article (sponge) can be obtained.
[0078]
As described above, the sound insulator of the present
invention is a material which realizes excellent sound insulation
properties while having a light weight, without relying on a
20 complex shape; therefore, the sound insulator of the present
invention can be used in a variety of applications. For example,
a sealing material for automobiles, a sealing material for
construction, a sealing material for railway vehicles, a sealing
material for ships, a sealing material for airplanes and the like,
5
SF-2924 34
which comprise the sound insulator of the present invention, are
all excellent sound insulation products.
EXAMPLES
[0079]
The present invention will now be described more concretely
by way of examples thereof; however, the present invention is not
restricted thereto by any means. In the tables below, the
numerical values of the respective components represent values
based on parts by mass.
10 (Composition Materials)
The composition materials used in Examples and Comparative
Examples are as follows.
A) Flexible Material
A-1) EPDM (trade name: Mitsui EPT 1045 (manufactured by
15 Mitsui Chemicals, Inc.); ethylene content: 58 wt%,
dicyclopentadiene content~ 5.0 wt%, Mooney viscosity [ML1• 4
(100°C)]: 38)
A-2) EPDM (trade name: Mitsui EPT 8030M (manufactured by
Mitsui Chemicals, Inc.); EPDM, content of a structural unit
20 derived from ethylene: 47% by mass, content of a structural unit
derived from 5-ethylidene-2-norbornene (ENB): 9.5% by mass,
Mooney viscosity [ML1+4 (100°C)]: 32)
A-3) EPDM obtained in accordance with the following
Polymerization Example 1
SF-2924 35
[Polymerization Example 1]
Using a 300-L polymerizer equipped with a stirring blade,
a quaternary copolymerization reaction was continuously
performed at 80°C using ethylene, propylene,
5 5-ethylidene-2-norbornene (ENB) and 5-vinyl-2-norbornene (VNB).
Using hexane (final concentration: 90.8% by weight) as a
polymerization solvent, ethylene, propylene, ENB and VNB were
continuously fed at concentrations of 3.1% by weight, 4.6% by
weight, 1.4% by weight and 0.11% by weight, respectively. While
10 maintaining the polymerization pressure at 0. 8 MPa, a metallocene
catalyst,
[N-(l,l-dimethylethyl)-l,l-dimethyl-1-[(1,2,3,3A,8A-~)-1,5,6,
7-tetrahydro-2-methyl-s-indacen-1-yl]silanaminato(2-)-KN] [(1,
2,3,4-~)-1,3-pentadiene]-titanium, was continuously fed as a
15 main catalyst to a concentration of 0. 0013 mmol/L. In addition,
as a co~catalyst and an organoaluminum compound, (C 6H5 .) 3CB (C 6F5 ) 4
and triisobutylaluminum (TIBA) were continuously fed to
concentrations of 0.0066 mmol/L and 0.0154 mmol/L, respectively.
It is noted here that the metallocene catalyst was synthesized
20 in accordance with the method described in WO 98/49212.
[0080]
In this manner, a polymerization reaction solution
containing 10.8% by weight of a copolymer rubber synthesized from
ethylene, propylene, ENB and VNB was obtained. The
SF-2924 36
polymerization reaction was terminated by adding a small amount
of methanol to the polymerization reaction solution withdrawn
from the bottom of the polymerizer. Then, after separating the
copolymer rubber from the solvent by a steam stripping treatment,
5 the copolymer rubber was dried at 80 °C under reduced pressure over
a whole day and night to obtain an
ethylene·propylene·non-conjugated diene random copolymer. In
this copolymer, the content of a structural unit derived from
ethylene was 4 6% by mass and the total content of structural units
10 derived from 5-ethylidene-2-norbornene (ENB) and
5-vinyl-2-norbornene (VNB) was 11.6% by mass, and the copolymer
had a Mooney viscosity [ML1+4 (160°C)] of 74.
[0081]
A-4) butyl rubber (IIR) (trade name: JSR BUTYL 268
15 (manufactured by JSR Corporation); degree of unsaturation (% by
mol): 1. 5%, Mooney viscosity [ML1+s (125°C)]: 51)
20
A-5) styrene-butadiene rubber (SBR) (trade name: SBR 1502
(manufactured by ZEON Corporation); amount of bound styrene:
23.5%, Mooney viscosity [ML1+4 (100°C)]: 52)
A-6) acrylonitrile-butadiene rubber (NBR) (trade name:
NIPOL 1042 (manufactured by ZEON Corporation), amount of bound
acrylonitrile: 33.5%, Mooney viscosity [ML1+4 (100°C)]: 77.5)
B) Resin
B-1) a polymer obtained in accordance with the following
SF-2924
Polymerization Example 2
[Polymerization Example 2]
37
To a stirring blade-equipped 1. 5-L SUS autoclave which had
been sufficiently purged with nitrogen, 300 ml of n-hexane (dried
5 over activated alumina in a dry nitrogen atmosphere) and 450 ml
of 4-methyl-1-pentene were introduced at 23°C. To this autoclave,
0. 7 5 ml of a 1. 0-mmol/ml toluene solution of triisobutylaluminum
(TIBAL) was added, and the stirrer was operated.
10
[0082]
Next, the autoclave was heated to an inner temperature of
60°C and pressurized with propylene to a total pressure of 0.40
MPa (gauge pressure). Then, 0.34 ml of a toluene solution
prepared in advance, which contained 1 mmol of methylaluminoxane
in terms of Al and 0.01 mmol of
15 diphenylmethylene(l-ethyl-3-t~butyl-cyclopentadienyl) (2,7-dit-
butyl-fluorenyl)zirconium dichloride, was injected with.
nitrogen into the autoclave, thereby initiating polymerization.
During the polymerization, the inner temperature of the autoclave
was controlled at 60°C. After 60 minutes from the initiation of
20 the polymerization, 5 ml of methanol was injected with nitrogen
into the autoclave to terminate the polymerization, and the
autoclave was depressurized to the atmospheric pressure. While
stirring the reaction solution, acetone was pour thereinto to
allow a polymer to precipitate.
SF-2924 38
[0083]
A solvent-containing polymer aggregate obtained by
filtering the reaction solution was dried at 100°C under reduced
pressure for 12 hours. The thus obtained polymer weighed 36.9
5 g and contained 72 mol% of a structural unit derived from
4-methyl-1-pentene and 28 mol% of a structural unit derived from
propylene. The polymer had a weight-average molecular weight
(Mw), which was determined by gel permeation chromatography (GPC),
of 337,000, a tan i5- Tg value of 28°C, and a maximum tan i5 value
10 of 2.4.
[0084]
15
B-2) hydrogenated styrene·isoprene ·styrene copolymer
(trade name: HYBRAR 5127 (manufactured by Kuraray Co., Ltd.), tan
i5- Tg: 18°C, maximum tan i5 value: 0.8)
B-3) hydrogenated styrene7based thermoplastic elastomer
(trade name: S.O.E. L605 (manufactured by Asahi Kasei
Corporation), tan i5
C) Vulcanization aid
Tg: 16°C, maximum tan i5 value: 1.5)
C-1) zinc oxide Type 2 (manufactured by Mitsui Mining &
20 Smelting Co., Ltd.)
C-2) active zinc oxide (trade name: META-Z102 (manufactured
by Inoue Calcium Corporation)
D) Processing aid
stearic acid (trade name: powder stearic acid "SAKURA"
SF-2924 39
(manufactured by NOF Corporation))
E) Reinforcing agent
carbon black (trade name: Asahi #55G (manufactured by As a hi
Carbon Co., Ltd.))
5 F) Filler
calcium carbonate (trade name: WHITON SB (manufactured by
Shiraishi Calcium Kaisha, Ltd.))
G) Activator
polyethylene glycol (trade name: PEG#4000 (manufactured by
10 Lion Corporation))
H) Softener
paraffin oil (trade name: DIANA PROCESS OIL PS-430
(manufactured by Idemitsu Kosan Co., Ltd.))
I) Vulcanizing agent
15 sulfur (trade name: ALPHAGRAN S-50EN (manufactured by
Touchi Co., Ltd.))
J) Vulcanization accelerator
J-1) thiuram-based vulcanization accelerator:
tetramethylthiuram disulfide (trade name: SANCELER TT
20 (manufactured by Sanshin Chemical Industry Co., Ltd.))
J-2) thiazole-based vulcanization accelerator:
2-mercaptobenzothiazole (trade name: SANCELER M (manufactured by
Sanshin Chemical Industry Co., Ltd.))
J-3) sulfenamide-based vulcanization accelerator:
SF-2924 40
N-(tert-butyl)-2-benzothiazole sulfenamide (trade name:
SANCELER NS-G (manufactured by Sanshin Chemical Industry Co.,
Ltd. ) )
J-4) thiazole-based vulcanization accelerator:
5 dibenzothiazyl disulfide (trade name: SANCELER DM (manufactured
by Sanshin Chemical Industry Co., Ltd.))
J-5) dithiocarbamate-based vulcanization accelerator:
zinc dibutyldithiocarbamate (trade name: SANCELER BZ
(manufactured by Sanshin Chemical Industry Co., Ltd.))
10 J-6) thiourea-based vulcanization accelerator:
2-imidazoline-2-thiol (trade name: SANCELER 22-C (manufactured
by Sanshin Chemical Industry Co., Ltd.))
J-7) dithiocarbamate-based vulcanization accelerator:
tellurium diethyldithiocarbamate (trade name: SANCELER TE-G
15 (manufactured by Sanshin Chemical Industry Co., Ltd.))
K) Foaming agent
4,4'-oxybis(benzenesulfonylhydrazide) (OBSH) (tradename:
NEOCELLBORN N#lOOOM (manufactured by Eiwa Chemical Ind. Co.,
Ltd.))
20 L) Moisture absorbent
f. calcium oxide (trade name: VESTA-18 (manufactured by Inoue
i'
Calcium Corporation))
.1
I
(Measurement and Evaluation Methods)
In the below-described Examples and Comparative Examples,
SF-2924 41
the physical properties were measured and evaluated by the
following methods.
a) Dynamic Viscoelasticity Measurement
The temperature dependence of the viscosity of each material
5 was measured under the below-described conditions using a
viscoelasticity tester "ARES" (manufactured by TA Instruments
JAPAN Inc.). The ratio of the thus measured storage elastic
modulus (G') and loss elastic modulus (G") was defined as "tan
o". When the tan o was plotted against temperature, a convex curve,
10 that is, a peak was obtained. The temperature at the apex of the
peak was defined as the glass transition temperature, that is,
"tan o- Tg", and the maximum value at this temperature was
determined. When two peaks were observed for the tan 6, the peaks
were defined as the first and second peaks, and the tan 6 - Tg
15 value and the maximum value wer,e recorded for both peaks.
20
[0085]
(Measurement Conditions)
Frequency: 1.0 Hz
Temperature: -70 to 80°C
Ramp Rate: 4.0°C/min
Strain: 0.5%
b) Sound Insulation Properties Test
A specimen was punched out from the subject press sheet and
tube-shaped sponge molded article, and the normal-incidence
'i
I
I
SF-2924 42
transmission loss thereof was measured using a 4206T-type
acoustic tube having an inner diameter of 29 mm~ (manufactured
by Bruel & Kjaer Sound & Vibration Measurement A/S) and a
measurement software (PULSE Material Testing Type 7758,
5 manufactured by Bruel & Kjaer Sound & Vibration Measurement A/S)
to determine the average transmission loss at 1 to 4 kHz and 4
to 6 kHz.
c) Specific Gravity and Specimen Weight
For each specimen used in the sound insulation properties
10 test, the mass was measured using an automatic densimeter
(manufactured by Toyo Seiki Seisaku-sho, Ltd.: M-1 type) under
25°C atmosphere, and the specific gravity was determined from the
difference between the mass in the air and the mass in pure water.
[Example 1]
15 Using MIXTRON BB MIXER (marufactured by Kobe Steel, Ltd.;
BB-4 type, volume: 2. 95 L, rotor: 4WH), 100 parts by mass of the
flexible material A-1 (EPDM), 40 parts by mass of the resin B-1,
5 parts by mass of the vulcanization aid C-1 (zinc oxide) and 1
part by mass of the processing aid (stearic acid) were kneaded.
20 The kneading was performed for 5 minutes at a rotor speed of 50
rpm and a floating weight pressure of 3 kg/cm2
, and the kneading
discharge temperature was 148°C.
[0086]
Then, after confirming that the thus kneaded composition
SF-2924 43
had a temperature of 40°C or lower, 1 part by mass of the
vulcanization accelerator J-1 (tetramethylthiuram disulfide),
0.5 parts by mass of the vulcanization accelerator J-2
(2-mercaptobenzothiazole) and 1.5 parts by mass of the
5 vulcanizing agent (sulfur) were added to the composition, and the
resulting mixture was kneaded using an 8-inch double-roll kneader.
As for the kneading conditions, the roll temperature was set as
front roll/rear roll = 50°C/50°C, the front roll speed was set
at 12.5 rpm, and the rear roll speed was set at 10.4 rpm. The
10 resulting kneaded product was rolled into a sheet form and then
heat-vulcanized at 160°C for 20 minutes using a hot press, thereby
obtaining a 2 mm-thick vulcanized sheet (press sheet) . This
vulcanized sheet was measured and evaluated as described above.
The results thereof are shown in Table 1.
15 [Comparative Examples 1 to 6]
For each of Comparative Examples 1 to 6, a vulcanized sheet
(press sheet) was prepared under the same conditions as in Example
1 except that the formulation was changed as shown in Table 1,
and the vulcanized sheet was measured and evaluated as described
20 above. In Comparative Example 2, however, an ethylene-a-olefin
copolymer (trade name: TAFMER DF605 (manufactured by Mitsui
Chemicals, Inc.), tan 6- Tg: -46°C, maximum tan 6 value: 0.5)
was used in place of the resin (B). The results are shown in Table
1.
SF-2924 44
[0087]
Further, with regard to the sound insulation properties of
Example 1 and Comparative Examples 1 to 6, the relationships
between the specimen mass and the average transmission loss are
5 shown in Fig. 1. Figs. 1(A) and 1(B) show the results for the
frequency ranges of 1 to 4 kHz and 4 to 6 kHz, respectively.
[0088]
[Table 1]
SF-2924 45
Example 1 Comparative Comparative Comparative Comparative Comparative Comparative
Example 1 Example 2 Example3 Example4 Example 5 Example 6
Flexible material A-1 100 100 100
A-2 100 100 100 100
Component Resin 8-1 40
TAFMER DF605 40
Reinforcing agent Carbon black 30 45 60
First peak
tan 1i- Tg (°C) -42 -42 -42 -36 -34 -34 -34
Dynamic Maximum value 0.67 1.15 0.94 1.71 1.37 1.19 1.01
viscoelasticity
tan 1i- Tg (0 measurement C) 32 - - - - - - Second peak
Maximum value 0.53 - - - - - -
Sound insulation Average 1 to 4kHz 34.7 32.7 32.5 32.3 33.5 34.5 35.4
property transmission loss 4 to 6kHz 38.8 36.3 36.9 36.7 38.0 38.7 . 39.5
Specific gravity 0.89 0.92 0.89 0.91 1.02 1.07 1.11
Mass of specimen used in sound insulation properties 1.18 1.21 1.18 1.21 1.35 1.41 1.46 test (g)
SF-2924 46
[0089]
As shown in Table 1 and Fig. 1, in the frequency ranges of
1 to 4 kHz and 4 to 6 kHz to which human ears are sensitive,
Comparative Examples 1 to 6 showed an improvement in the
5 transmission loss as the mass of the specimen used for the
measurements was increased. In Example 1, it is confirmed that
the sound insulation properties were superior as compared to those
of Comparative Examples 1 to 6 even when the mass of the specimen
of Example 1 was either the same or less than those of Comparative
10 Examples 1 to 6. From these results, it is seen that, in the sound
insulator of the present invention, a reduction in weight can be
achieved while maintaining the sound insulation properties of
conventional sound insulators or the sound insulation properties
can be improved while maintaining the lightweightness of
15 conventional sound insulators.
[Example 2]
Using an 8-inch double-roll kneader under the kneading
conditions where the roll temperature was set as front roll/rear
roll= 70°C/70°C; the front roll speed was set at 12.5 rpm; and
tel ii ::
20 the rear roll speed was set at 10.4 rpm, 100 parts by mass of the
n flexible material A-4 (butyl rubber), 40 parts by mass of the resin
:!
fi
:-! B-1, 3 parts by mass of the vulcanization aid C-1 (zinc oxide)
and 1 part by mass of the processing aid (stearic acid) were kneaded
to homogeneity and, after adding thereto 1 part by mass of the
SF-2924 47
vulcanization accelerator J-1 (tetramethylthiuram disulfide) and
1. 7 5 parts by mass of the vulcanizing agent (sulfur) , the resultant
was further kneaded to homogeneity. Then, the resulting kneaded
product was rolled into a sheet form and heat-vulcanized at 160 °C
5 for 30 minutes using a hot press, thereby obtaining a 2 mm-thick
vulcanized sheet (press sheet) . This vulcanized sheet was
measured and evaluated as described above. The results thereof
are shown in Table 2.
[Comparative Examples 7 and 8]
10 For each of Comparative Examples 7 and 8, a vulcanized sheet
(press sheet) was prepared under the same conditions as in Example
2 except that the formulation was changed as shown in Table 2,
and the vulcanized sheet was measured and evaluated as described
above. In Comparative Example 8, however, an ethylene-a-olefin
15 copolymer (trade name: TAFMER DF605 (manufactured by Mitsui
Chemicals, Inc.), tan 6- Tg: -46°C, maximum tan 6 value: 0.5)
was used in place of the resin (B) . The results are shown in Table
2.
[0090]
20 [Table 2]
Comparative Comparative
Example 2
Example 7 Example B
Component Flexible material A-4 100 100 100
SF-2924 48
Resin B-1 40
TAFMER DF605 40
tan i5- Tg ("C) -38 -38 -40
Dynamic First peak
Maximum value 0.68 1.31 1.02
viscoelasticity
tan i5- Tg (0 C) 32 - -
measurement Second peak
Maximum value 0.53 - -
Average 1 to 4kHz 35.0 33.5 33.5
Sound insulation
transmission
property 4 to 6kHz 39.3 38.2 38.0
loss
Specific gravity 0.913 0.944 0.927
Mass of specimen used in sound insulation properties
1.21 1.25 1.23
test (g)
[0091]
From the results of the sound insulation properties test,
as shown in Table 2, it is seen that Example 2 had superior sound
insulation properties than Comparative Examples 7 and 8 in .both
5 frequency ranges of 1 to 4 kHz and 4 to 6 kHz, despite that the
mass of the specimen of Example 2 was less than those of Comparative
Examples 7 and 8.
[Example 3]
Using an 8-inch double-roll kneader under the kneading
10 conditions where the roll temperature was set as front roll/rear
roll= 70°C/70°C; the front roll speed was set at 12.5 rpm; and
the rear roll speed was set at 10.4 rpm, 100 parts by mass of the
SF-2924 49
flexible material A-5 (styrene-butadiene rubber), 40 parts by
mass of the resin B-1, 3 parts by mass of the vulcanization aid
C-1 (zinc oxide) and 1 part by mass of the processing aid (stearic
acid) were kneaded to homogeneity and, after adding thereto 1 part
5 by mass of the vulcanization accelerator J-3
(N-(tert-butyl)-2-benzothiazole sulfenamide) and 1.75 parts by
mass of the vulcanizing agent (sulfur), the resultant was further
kneaded to homogeneity. Then, the resulting kneaded product was
rolled into a sheet form and heat-vulcanized at 160°C for 30
10 minutes using a hot press, thereby obtaining a 2 mm-thick
vulcanized sheet (press sheet). This vulcanized sheet was
measured and evaluated as described above. The results thereof
are shown in Table 3.
[Comparative Examples 9 and 10]
15 For each of Comparative Exall)ples 9 and 10, a vulcanized sheet
(press sheet) was prepared under the same conditions as in Example . . ' ' .
3 except that the formulation was changed as shown in Table 3,
and the vulcanized sheet was measured and evaluated as described
above. In Comparative Example 10, however, an ethylene-a-olefin
20 copolymer (trade name: TAFMER DF605 (manufactured by Mitsui
Chemicals, Inc.), tan 6- Tg: -46°C, maximum tan 6 value: 0.5)
was used in place of the resin (B). The results are shown in Table
3.
[0092]
SF-2924 50
[Table 3]
Comparative Comparative
Example 3
Example 9 Example 10
Flexible material A-5 100 100 100
Component Resin 8-1 40
T AFMER DF605 40
tan o- Tg (0 C} -40 -38 -40
First peak
Dynamic viscoelasticity Maximum value 0.59 2.05 1.19
measurement tan o- Tg (°C) 26 - -
Second peak
Maximum value 0.72 - -
Average 1 to 4kHz 36.1 32.5 32.3
Sound insulation
transmission
property 4 to 6kHz 37.9 36.8 36.8
loss
Specific gravity 0.934 0.968 0.943
Mass of specimen used in sound insulation properties test
1.23 1.28 1.25
(g)
[0093]
From the results of the sound insulation properties test,
as shown in Table 3, it is seen that Example 3 had superior sound
5 insulation properties than Comparative Examples 9 and 10 in both
frequency ranges of 1 to 4 kHz and 4 to 6 kHz, despite that the
mass of the specimen of Example 3 was less than those of Comparative
Examples 9 and 10.
[Example 4]
SF-2924 51
Using an 8-inch double-roll kneader under the kneading
conditions where the roll temperature was set as front roll/rear
roll= 70°C/70°C; the front roll speed was set at 12.5 rpm; and
the rear roll speed was set at 10.4 rpm, 100 parts by mass of the
5 flexible material A-6 (acrylonitrile-butadiene rubber), 40 parts
by mass of the resin B-1, 3 parts by mass of the vulcanization
aid C-1 (zinc oxide) and 1 part by mass of the processing aid
(stearic acid) were kneaded to homogeneity and, after adding
thereto 0.7 parts by mass of the vulcanization accelerator J-3
10 (N-(tert-butyl)-2-benzothiazole sulfenamide) and 1.55 parts by
mass of the vulcanizing agent (sulfur), the resultant was further
kneaded to homogeneity. Then, the resulting kneaded product was
rolled into a sheet form and heat-vulcanized at l60°C for 30
minutes using a hot press, thereby obtaining a 2 mm-thick
15 vulcanized sheet (press sheet)., This vulcanized sheet was
measured and evaluated as described above. The results thereof
are shown in Table 4.
[Comparative Examples 11 and 12]
For each of Comparative Examples 11 and 12, a vulcanized
20 sheet (press sheet) was prepared under the same conditions as in
Example 4 except that the formulation was changed as shown in Table
4, and the vulcanized sheet was measured and evaluated as described
above. In Comparative Example 12, however, an ethylene-a-olefin
copolymer (trade name: TAFMER DF605 (manufactured by Mitsui
I
SF-2924 52
Chemicals, Inc.), tan 6- Tg: -46°C, maximum tan 6 value: 0.5)
was used in place of the resin (B). The results are shown in Table
4.
[0094]
5 [Table 4]
Component
Dynamic
viscoelasticity
measurement
Sound insulation
property
Specific gravity
Flexible material A-6
Resin B-1
TAFMER DF605
tan 1i- Tg (0 C}
First peak
Maximum value
tan 1i- Tg (°C)
Second peak
Maximum value
Average 1 to 4kHz
transmissionloss 4 to 6kHz
Mass of specimen used in sound insulation properties
test (g)
[0095]
Example4
100
40
-18
0.59
26
0.82
35.3
40.2
0.956
1.26
Comparative Comparative
Example 11 Example 12
100 100
40
-16 -50
1.80 0.09
- -16
- 1.09
34.0 33.1
38.5 37.5
..
1.017 0.967
1.34 1.28
From the results of the sound insulation properties test,
as shown in Table 4, it is seen that Example 4 had superior sound
insulation properties than Comparative Examples 11 and 12 in both
10 frequency ranges of 1 to 4 kHz and 4 to 6 kHz, despite that the
SF-2924 53
mass of the specimen of Example 4 was less than those of Comparative
Examples 11 and 12.
[Example 5]
Using MIXTRON BB MIXER (manufactured by Kobe Steel, Ltd.;
5 BB-4 type, volume: 2. 95 L, rotor: 4WH), 100 parts by mass of the
flexible material A-3 (EPDM), 40 parts by mass of the resin B-1,
8 parts by mass of the vulcanization aid C-2 (active zinc oxide),
2 parts by mass of the processing aid (stearic acid), 88 parts
by mass of the reinforcing agent (carbon black) , 50 parts by mass
10 of the filler (calcium carbonate) , 1 part by mass of the activator
(polyethylene glycol) and 71 parts by mass of the softener
(paraffin oil) were kneaded. The kneading was performed for 5
minutes at a rotor speed of 50 rpm and a floating weight pressure
of 3 kg/cm2
, and the kneading discharge temperature was 152°C.
15 [0096]
After confirming that the thus kneaded composition had a
temperature of 40°C or lower, 1.5 parts by mass of the
vulcanization accelerator J-4 (dibenzothiazyl disulfide), 2
parts by mass of the vulcanization accelerator J-5 (zinc
20 dibutyldithiocarbamate), 1 part by mass of the vulcanization
accelerator J-6 (2-imidazoline-2-thiol) , 0. 1 parts by mass of the
vulcanization accelerator J-7 (tellurium
diethyldi thiocarbamate) and 1. 5 parts by mass of the vulcanizing
agent (sulfur) were added to the composition, and the resulting
SF-2924 54
mixture was kneaded using a 14-inch double-roll kneader. As for
·the kneading conditions, the roll temperature was set as front
roll/rear roll = 60°C/55°C, the front roll speed was set at 13
rpm, and the rear roll speed was set at 11.5 rpm. The resulting
5 kneaded product was rolled into a sheet form and then
heat-vulcanized at 180°C for 10 minutes using a hot press, thereby
obtaining a 2 mm-thick vulcanized sheet (press sheet). This
vulcanized sheet was measured and evaluated as described above.
The results thereof are shown in Table 5.
10 [Examples 6 to 10]
For each of Examples 6 to 10, a vulcanized sheet (press
sheet) was prepared under the same conditions as in Example 5
except that the formulation was changed as shown in Table 5, and
the vulcanized sheet was measured and evaluated as described above.
15 The results thereof are shown in Table 5.
[Comparative Examples 13 to 15]
For each of Comparative Examples 13 to 15, a vulcanized sheet
(press sheet) was prepared under the same conditions as in Example
5 except that the formulation was changed as shown in Table 5,
20 and the vulcanized sheet was measured and evaluated as described
above. It is noted here, however, that an ethylene-a-olefin
copolymer (TAFMER DF605 (manufactured by Mitsui Chemicals, Inc. ) ,
tan 6- Tg: -46°C, maximum tan 6 value: 0.5) was used in place
of the resin (B) in Comparative Example 14 and a polyolefin-based
SF-2924 55
copolymer (trade name: NOTIO SN02 85 (manufac·tured by Mitsui
Chemicals, Inc.), tan o- Tg: -l0°C, maximum tan o value: 1.2)
was used in place of the resin (B) in Comparative Example 15. The
results are shown in Table 5.
5 [0097]
[Table 5]
·o.,.:·:oc-.:-~cc~·c.:·':c:: ·-·~c<:-: c-.-.· •. -
SF-2924 56
Example Example Example Example Example Example Comparative Comparative Comparative
5 6 7 8 9 10 Example 13 Example 14 Example 15
Flexible A-3 100 100 100 100 100 100 100 100 material 100
B-1 20 40
Component Resin B-2 20 40
B-3 20 40
TAFMER DF605 40
NOTIO SN0285 40
tan o- Tg (•C) -38 -38 -42 -40 -42 -40 -38 -40 -36
Dynamic First peak
Maximum value 0.93 0.66 0.70 0.44 0.83 0.54 1.20 1.01 0.64
viscoelasticity
measurement tan o- Tg (•C) 14 14 12 12 6 8 - - -
Second peak
Maximum value 0.27 0.47 0.40 0.69 0.38 0.59 - - -
Average 1 to 4kHz 35.5 35.4 35.9 36.8 35.8 35.8 34.7 34.7 . Sound insulation 35.3
property transmission
loss 4 to 6kHz 39c9 . 40.4 40.9 40.5 40.2 40.6 39.6 39.7 39.5
Specific gravity 1.15 1.12 1.16 1.15 1.17 1.16 1.18 1.13 1.14
Mass of specimen used in sound insulation
I properties test (g) 1:.52 1.49 1.53 1.52 1.54 1.53 1.55 1.50 1.51
SF-2924 57
[0098]
From the results of the sound insulation properties test,
as shown in Table 5, it is seen that Examples 5 to 10 had superior
sound insulation properties than Comparative Examples 13 to 15
5 in both frequency ranges of 1 to 4 kHz and 4 to 6 kHz, even when
the mass of the specimen in Examples 5 to 10 was less than that
in Comparative Examples 13 to 15.
[Example 11]
Using MIXTRON BB MIXER (manufactured by Kobe Steel, Ltd.;
10 BB-4 type, volume: 2. 95 L, rotor: 4WH), 100 parts by mass of the
flexible material A-3 (EPDM), 40 parts by mass of the resin B-1,
8 parts by mass of the vulcanization aid C-2 (active zinc oxide),
2 parts by mass of the processing aid (stearic acid), 88 parts
by mass of the reinforcing agent (carbon black) , 50 parts by mass
15 of the filler (calcium carbonate)., 1 part by mass of the activator
(polyethylene glycol), 71 parts by mass of the softener (paraffin
oil) and 5 parts by mass of the moisture absorbent (calcium oxide)
were kneaded. The kneading was performed for 5 minutes at a rotor
speed of 50 rpm and a floating weight pressure of 3 kg/cm2
, and
20 the kneading discharge temperature was 152°C.
[0099]
After confirming that the thus kneaded composition had a
temperature of 40°C or lower, 2.6 parts by mass of the foaming
agent ( 4, 4 '-oxybis (benzenesulfonylhydrazide) ) , 1. 5 parts by mass
SF-2924 58
of the vulcanization accelerator J-4 (dibenzothiazyl disulfide),
2 parts by mass of the vulcanization accelerator J-5 (zinc
dibutyldithiocarbamate), 1 part by mass of the vulcanization
accelerator J-6 ( 2-imidazoline-2-thiol) , 0. 1 parts by mass of the
5 vulcanization accelerator J-7 (tellurium
diethyldithiocarbamate) and 1. 5 parts by mass of the vulcanizing
agent (sulfur) were added to the composition, and the resulting
mixture was kneaded using a 14-inch double-roll kneader. As for
the kneading conditions, the roll temperature was set as front
10 roll/rear roll = 60°C/55°C, the front roll speed was set at 13
rpm and the rear roll speed was set at 11.5 rpm, and the kneaded
product was rolled into a ribbon form.
[0100]
Next, using a 60-mm~ extruder equipped with a tube-shaped
15 die (inner diameter: 12 mm, thickness: 1. 5 mm) , the thus obtained
ribbon-form composition was extruded and molded into a tube form
under the conditions of a die temperature of 80°C and a cylinder
temperature of 60°C. Simultaneously with the molding, the
resulting molded article was introduced to a 1-kHz microwave
20 vulcanization chamber set at 230°C and then to a straight-type
hot-air vulcanizer (HAV) set at 250°C, thereby subjecting the
molded article to heating for 5 minutes to perform cross-linking
and foaming, as a result of which a tube-shaped sponge molded
article was obtained. This sponge molded article was cut out and
5
SF-2924 59
a specimen was punched out, and the thus obtained specimen was
measured and evaluated as described above. The results thereof
are shown in Table 6.
[Examples 12 to 16]
For each of Examples 12 to 16, a tube-shaped sponge molded
article was prepared and a specimen was obtained under the same
conditions as in Example 11, except that the formulation and the
vulcanization condition were changed as shown in Table 6. The
thus obtained specimen was measured and evaluated as described
10 above. The results thereof are shown in Table 6.
[Comparative Examples 16 to 20]
For each of Comparative Examples 16 to 20, a tube-shaped
sponge molded article was prepared and a specimen was obtained
under the same conditions as in Example 11, except that the
15 formulation and the vulcanization condition were changed as shown
in Table 6. The thus obtained specimen was measured and eval~ated
as described above. The results thereof are shown in Table 6.
[0101]
Further, with regard to the sound insulation properties of
20 Examples 11 to 16 and Comparative Examples 16 to 20, the
relationships between the specimen mass and the average
transmission loss are shown in Fig. 2. Figs. 2(A) and 2(B) show
the results for the frequency ranges of 1 to 4 kHz and 4 to 6 kHz,
respectively.
SF-2924
[0102]
[Table 6]
60
SF-2924 61
Example Example Example Example Example Example Comparative Comparative Comparative Comparative Comparative
11 12 13 14 15 16 Example 16 Example 17 Example 18 Example 19 Example 20
Flexible
material A-3 100 100 100 100 100 100 100 100 100 100 100
B-1 20 20 20 20 - - - - - - -
Resin
B-2 - - - - 20 20 - - - - -
Component Reinforcing Carbon
88 88 81 81 81 81 81 81 81 81 81
agent black
Softener Paraffin oil 71 71 78 78 78 78 78 78 78 78 78
Foaming
agent OBSH 2.6 2.6 2.6 2.6 2.6 2.6 1.5 2.6 3.3 3.3 4.0
Continuous
vulcanization Microwave (kHz) 1 2 1 2 1 2 1 1 1 2 1
condition
tano- Tg -38 -38 -38 -38 -40 -40 -38 -40 -40 -40 -38
First peak
oc)
Dynamic Maximum
value
0.88 0.86 0.85 0.84 0.72 0.71 1.19 1.16 1.07 1.12 1.12
viscoelasticity
measurement tan o- Tg
Second oc) 14 14 16 16 12 12 - - - - -
peak Maximum
value 0.29 0.28 0.28 0.27 0.38 0.38 - - - - -
Sound Average 1 to 4kHz 28.2 27.8 27.5 27.3 28.4 28.4 29.0 27.4 28.5 26.1 25.8
insulation transmission
:property loss 4 to 6kHz 33.1 32.7 32.4 32.1 33.2 33.2 33.6 32.0 30.9 30.6 30.0
Specific gravity 0.56 0.53 0.53 0.50 0.53 0.51 0.71 0.50 0.43 0.43 0.38
Thickness (mm) 2.04 2.09 2.10 2.14 2.22 2.25 1.84 2.29 2.47 2.38 2.57
Mass of specimen used in sound
insulation properties test (g) 0.75 0.73 0.73 0.71 0.78 0.76 0.86 0.76 0.70 0.68 0.64
SF-2924 62
[0103]
As shown in Table 6 and Fig. 2, in the frequency ranges of
1 to 4 kHz and 4 to 6 kHz to which human ears are sensitive,
Comparative Examples 16 to 20 showed an improvement in the
5 transmission loss as the mass of the specimen used for the
measurements was increased. In Examples 11 to 16, it is confirmed
that the sound insulation properties were superior as compared
to those of Comparative Examples where the specimens had the same
mass as those of Examples 11 to 16. From these results, it is
10 seen that, in the sound insulator of the present invention, a
reduction in weight can be achieved while maintaining the sound
insulation properties of conventional sound insulators or the
sound insulation properties can be improved while maintaining the
lightweightness of conventional sound insulators.

CLAIMS
1. A sound insulator comprising:
a flexible material (A) having a peak of loss tangent (tan
6), which is determined by dynamic viscoelasticity measurement,
5 in a temperature range of -60°C to lower than 0°C; and
a resin (B) having a peak of loss tangent (tan 6), which
is determined by dynamic viscoelasticity measurement, in a
temperature range of 0°C to 60°C,
said sound insulator comprising said resin (B) at a ratio
10 of 1 to 50 parts by mass with respect to 100 parts by mass of said
flexible material (A) .
15
2. The sound insulator according to claim 1, wherein said
flexible material (A) comprises at least one selected from
ethylene-based rubbers, natural rubbers and diene-based rubbers.
3 0 The sound insulator according to claim 1, wherein said
flexible material (A) comprises an
ethylene·a-olefin·non-conjugated polyene copolymer (a).
4. The sound insulator according to claim 3, wherein said
ethylene·a-olefin·non-conjugated polyene copolymer (a)
20 comprises a structural unit derived from ethylene in an amount
of 40 to 72% by mass and a structural unit derived from a
non-conjugated polyene in an amount of 2 to 15% by mass.
5. The sound insulator according to any one of claims 1 to 4,
wherein said resin (B) comprises at least one selected from
SF-2924 64
aromatic polymers, 4-methyl-1-pentene·a-olefin copolymer (b),
polyvinyl acetates, polyesters, polyurethanes,
poly(meth)acrylates, epoxy resins and polyamides.
6. The sound insulator according to any one of claims 1 to 4,
5 wherein said resin (B) comprises a 4-methyl-1-pentene·a-olefin
copolymer (b-1) which contains 16 to 95% by mol of a structural
unit (i) derived from 4-methyl-1-pentene, 5 to 84% by mol of a
structural unit (ii) derived from at least one a-olefin selected
from a-olefins having 2 to 20 carbon atoms excluding
10 4-methyl-1-pentene and 0 to 10% by mol of a structural unit (iii)
derived from a non-conjugated polyene (with a proviso that the
total amount of said structural units (i), (ii) and (iii) is 100%
by mol).
7. The sound insulator according to any one of claims 1 to 6,
15 which is obtained by cross-linking a composition comprising said
flexible material (A) and said resin (B) using a vulcanizing agent.
8. The sound insulator according to any one of claims 1 to 7,
wherein at least a portion of said sound insulator is a foamed
article.
20 9. A sealing material for automobiles, comprising the sound
insulator according to any one of claims 1 to 8.
10. A sealing material for construction, comprising the sound
insulator according to any one of claims 1 to 8.
11. A sealing material for railway vehicles, comprising the
SF-2924 65
sound insulator according to any one of claims 1 to 8.
12. A sealing material for ships, comprising the sound insulator
according to any one of claims 1 to 8.
13. A sealing material for airplanes, comprising the sound
fi insulator according to any one of claims 1 to 8.