U.S. patent application number 15/127824 was filed with the patent office on 2017-04-13 for latex of the highly saturated nitrile rubber and adhesive composition.
This patent application is currently assigned to ZEON CORPORATION. The applicant listed for this patent is ZEON CORPORATION. Invention is credited to Tomonori NAKASHIMA, Osamu SENDA.
Application Number | 20170101558 15/127824 |
Document ID | / |
Family ID | 54195561 |
Filed Date | 2017-04-13 |
United States Patent
Application |
20170101558 |
Kind Code |
A1 |
NAKASHIMA; Tomonori ; et
al. |
April 13, 2017 |
LATEX OF THE HIGHLY SATURATED NITRILE RUBBER AND ADHESIVE
COMPOSITION
Abstract
A latex of a highly saturated nitrile rubber wherein the highly
saturated nitrile rubber contains .alpha.,.beta.-ethylenically
unsaturated nitrile monomer units in a ratio of 10 to 60 wt %, has
an iodine value of 120 or less, and has a weight average molecular
weight of solubles in chloroform of 100,000 or less, and when
removing volatiles contained in the latex and making a film of the
highly saturated nitrile rubber, a loss tangent tan
.delta..sub.(50.degree. C.) at 50.degree. C. of the film is 0.3 to
0.6 and a complex torque S* at the time of 100% shear strain at
100.degree. C. of the film is 20 dNm or less, and an adhesive
composition containing the latex are provided.
Inventors: |
NAKASHIMA; Tomonori; (Tokyo,
JP) ; SENDA; Osamu; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ZEON CORPORATION |
Tokyo |
|
JP |
|
|
Assignee: |
ZEON CORPORATION
Tokyo
JP
|
Family ID: |
54195561 |
Appl. No.: |
15/127824 |
Filed: |
March 25, 2015 |
PCT Filed: |
March 25, 2015 |
PCT NO: |
PCT/JP2015/059110 |
371 Date: |
September 21, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08C 19/02 20130101;
B32B 7/12 20130101; B32B 25/10 20130101; B32B 2255/10 20130101;
C09J 109/04 20130101; C08K 7/02 20130101; C08F 236/12 20130101;
C08L 9/04 20130101; C08F 2/38 20130101; C08F 236/12 20130101; B32B
2255/26 20130101; C09J 161/14 20130101; C08K 7/02 20130101; C08L
9/04 20130101 |
International
Class: |
C09J 109/04 20060101
C09J109/04; B32B 7/12 20060101 B32B007/12; B32B 25/10 20060101
B32B025/10; C08L 9/04 20060101 C08L009/04 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 27, 2014 |
JP |
2014-064989 |
Claims
1. A latex of a highly saturated nitrile rubber wherein the highly
saturated nitrile rubber contains .alpha.,.beta.-ethylenically
unsaturated nitrile monomer units in a ratio of 10 to 60 wt %, has
an iodine value of 120 or less, and has a weight average molecular
weight of solubles in chloroform of 100,000 or less, and when
removing volatiles contained in the latex and making a film of the
highly saturated nitrile rubber, a loss tangent tan
.delta..sub.(50.degree. C.) at 50.degree. C. of the film is 0.3 to
0.6 and a complex torque S* at the time of 100% shear strain at
100.degree. C. of the film is 20 dNm or less.
2. The latex of a highly saturated nitrile rubber according to
claim 1, wherein when removing volatiles contained in the latex and
making a film of the highly saturated nitrile rubber, a difference
.DELTA. tan .delta.=tan .delta..sub.(150.degree. C.)-tan
.delta..sub.(50.degree. C.), which is a difference of the loss
tangent tan .delta..sub.(50.degree. C.) at 50.degree. C. and a loss
tangent tan .delta..sub.(150.degree. C.) at 150.degree. C. of the
film, is 0.35 or less.
3. The latex of a highly saturated nitrile rubber according to
claim 1, wherein when removing volatiles contained in the latex and
making a film of the highly saturated nitrile rubber, a storage
modulus G'.sub.(100.degree. C.) at 100.degree. C. of the film is
200 kPa or less.
4. The latex of a highly saturated nitrile rubber according to
claim 1, wherein the highly saturated nitrile rubber contains 10 to
60 wt % of .alpha.,.beta.-ethylenically unsaturated nitrile monomer
units, 0.1 to 20 wt % of acid group-containing
.alpha.,.beta.-ethylenically unsaturated monomer units, and 20 to
89.9 wt % of diene monomer units and/or .alpha.-olefin monomer
units.
5. The latex of a highly saturated nitrile rubber according to
claim 1, wherein the latex of a highly saturated nitrile rubber is
one obtained by emulsion polymerization of monomers forming the
highly saturated nitrile rubber and the latex of a highly saturated
nitrile rubber is one obtained through a process of not adding a
molecular weight modifier at the time of start of emulsion
polymerization and adding 1 to 3 parts by weight of a molecular
weight modifier, after start of emulsion polymerization, with
respect to 100 parts by weight of the monomers used for
polymerization at the stage of a 5 to 60 wt % polymerization
conversion rate.
6. An adhesive composition comprising the latex of a highly
saturated nitrile rubber according to claim 1.
7. The adhesive composition according to claim 6 further comprising
a resorcinol formaldehyde resin.
8. The adhesive composition according to claim 7 wherein a content
of the resorcinol formaldehyde resin is 5 to 30 parts by weight
with respect to 100 parts by weight of a solid content of the latex
of a highly saturated nitrile rubber.
9. A fiber base material-highly saturated nitrile rubber composite
obtained by bonding a fiber base material and a highly saturated
nitrile rubber using the adhesive composition according to claim 6.
Description
TECHNICAL FIELD
[0001] The present invention relates to a latex of a highly
saturated nitrile rubber and an adhesive composition containing the
same.
BACKGROUND ART
[0002] Composites of rubber and fiber are being used in numerous
fields such as belts, rubber hoses, and diaphragms. In the field of
belts, there are timing belts for automobile use, poly ribbed
belts, lapped belts, V-belts, etc. These are usually comprised of
composites of woven fabric-shaped base and rubber. For example, in
V-belts, the belts are surrounded by canvas for protection, while
in toothed belts, the tooth parts have covering fabric laminated
over them.
[0003] As the rubber, in the past, the oil resistant rubbers of
chloroprene rubber and acrylonitrile-butadiene copolymer rubber had
mainly been used, but in recent years, to deal with automobile
emission regulations, the smaller engine compartments for
lightening the weight of automobiles, the closed engine
compartments for reducing noise, etc., heat resistance is demanded.
For this reason, highly saturated nitrile rubber provided with both
heat resistance and oil resistance has come to be used.
[0004] In this regard, if using a timing belts as an example, the
tooth parts are protected by nylon base fabric. In the timing
belts, the base fabric, in general, has been treated by a
solvent-based rubber glue in order to raise the bonding strength of
the rubber and the base fabric and suppress abrasion due to
intermeshing of the belt and gear. However, recently, to eliminate
environmental pollution due to organic solvents, art for treatment
by an aqueous binder in place of treatment by a solvent-based
rubber glue has been desired.
[0005] As such art for treatment by an aqueous binder, Patent
Document 1 discloses an adhesive composition which contains a
carboxyl group-containing highly saturated nitrile rubber latex and
resorcinol formaldehyde resin. However, the fiber base
material-highly saturated nitrile rubber composite obtained by
using this adhesive composition to bond a fiber base material and
highly saturated nitrile rubber is not necessarily sufficient in
abrasion resistance. For this reason, it has not been possible to
sufficiently respond to the recent trend toward higher performance
of engine compartments of automobiles.
RELATED ART DOCUMENTS
Patent Documents
[0006] Patent Document 1: Japanese Patent Publication No.
6-286015A
DISCLOSURE OF THE INVENTION
Problem to be Solved by the Invention
[0007] An object of the present invention is to provide an adhesive
composition which can form an adhesive layer excellent in
stretchability and abrasion resistance and is to provide a latex of
a highly saturated nitrile rubber used for this adhesive
composition.
Means for Solving the Problems
[0008] The inventors engaged in intensive studies on a highly
saturated nitrile rubber forming a latex which is an ingredient of
an adhesive composition, for achieving the above object and as a
result discovered that by controlling the weight average molecular
weight of the solubles in chloroform to 100,000 or less and making
the loss tangent tan .delta..sub.(50.degree. C.) at 50.degree. C.
when made into a film and making the complex torque S* at the time
of 100% shear strain at 100.degree. C. predetermined ranges, it is
possible to achieve the above object and thereby completed the
present invention.
[0009] That is, according to the present invention, there is
provided a latex of a highly saturated nitrile rubber which
contains 10 to 60 wt % of .alpha.,.beta.-ethylenically unsaturated
nitrile monomer units, has an iodine value of 120 or less, and has
a weight average molecular weight of solubles in chloroform of
100,000 or less, and when removing volatiles contained in the latex
and making a film of the highly saturated nitrile rubber, a loss
tangent tan .delta..sub.(50.degree. C.) at 50.degree. C. of the
film is 0.3 to 0.6 and a complex torque S* at the time of 100%
shear strain at 100.degree. C. of the film is 20 dNm or less.
[0010] In the latex of a highly saturated nitrile rubber of the
present invention, preferably, when removing volatiles contained in
the latex and making a film of the highly saturated nitrile rubber,
a difference .DELTA. tan .delta.=tan .delta..sub.(150.degree.
C.)-tan .delta..sub.(50.degree. C.), which is a difference of the
loss tangent tan .delta..sub.(50.degree. C.) at 50.degree. C. and a
loss tangent tan .delta..sub.(150.degree. C.) at 150.degree. C. of
the film, is 0.35 or less.
[0011] In the latex of a highly saturated nitrile rubber of the
present invention, preferably when removing volatiles contained in
the latex and making a film of the highly saturated nitrile rubber,
a storage modulus G' .sub.(100.degree. C.) at 100.degree. C. of the
film is 200 kPa or less.
[0012] In the latex of a highly saturated nitrile rubber of the
present invention, preferably the highly saturated nitrile rubber
contains 10 to 60 wt % of .alpha.,.beta.-ethylenically unsaturated
nitrile monomer units, 0.1 to 20 wt % of acid group-containing
.alpha.,.beta.-ethylenically unsaturated monomer units, 20 to 89.9
wt % of and diene monomer units and/or .alpha.-olefin monomer
units.
[0013] Further, preferably the latex of a highly saturated nitrile
rubber of the present invention is one obtained by emulsion
polymerization of a monomer forming the highly saturated nitrile
rubber and the latex of a highly saturated nitrile rubber is one
obtained through a process of not adding a molecular weight
modifier at the time of start of emulsion polymerization and adding
1 to 3 parts by weight of a molecular weight modifier, after start
of emulsion polymerization, with respect to 100 parts by weight of
the monomers used for polymerization at the stage of a 5 to 60 wt %
polymerization conversion rate.
[0014] Further, according to the present invention, there is
provided an adhesive composition containing a latex of a highly
saturated nitrile rubber of the present invention.
[0015] The adhesive composition of the present invention preferably
further contains a resorcinol formaldehyde resin. Further, the
content of the resorcinol formaldehyde resin is preferably 5 to 30
parts by weight with respect to 100 parts by weight of a solid
content of the latex of a highly saturated nitrile rubber.
[0016] Furthermore, according to the present invention, there is
provided a fiber base material-highly saturated nitrile rubber
composite obtained by bonding a fiber base material and a highly
saturated nitrile rubber using the adhesive composition of the
present invention.
Effects of the Invention
[0017] The adhesive composition of the present invention using a
latex of the highly saturated nitrile rubber of the present
invention can form an adhesive layer which is excellent in
stretchability (which requires low load for stretching to
predetermined ratio) and abrasion resistance. Further, by using
such an adhesive composition of the present invention as an
adhesive, it is possible to improve the stretchability after
treating the fiber base material with the adhesive composition and,
further, obtain a composite excellent in abrasion resistance.
DESCRIPTION OF EMBODIMENTS
Latex of the Highly Saturated Nitrile Rubber
[0018] The latex of the highly saturated nitrile rubber of the
present invention comprises highly saturated nitrile rubber
containing 10 to 60 wt % of .alpha.,.beta.-ethylenically
unsaturated nitrile monomer units, having an iodine value of 120 or
less, and having a weight average molecular weight of solubles in
chloroform of 100,000 or less. When removing the volatiles
contained in the latex and forming a film of the highly saturated
nitrile rubber, the film is provided with the later explained
specific properties.
[0019] The .alpha.,.beta.-ethylenically unsaturated nitrile monomer
forming the .alpha.,.beta.-ethylenically unsaturated nitrile
monomer units contained in the highly saturated nitrile rubber
forming the latex of the present invention is not particularly
limited, but one which has 3 to 18 carbon atoms is preferable,
while one which has 3 to 9 carbon atoms is particularly preferable.
As specific examples, acrylonitrile, methacrylonitrile,
.alpha.-chloroacrylonitrile, etc. may be mentioned. Among these as
well, acrylonitrile is preferable. These
.alpha.,.beta.-ethylenically unsaturated nitrile monomer may be
used as single types alone or as a plurality of types.
[0020] In the highly saturated nitrile rubber forming the latex of
the present invention, the content of the
.alpha.,.beta.-ethylenically unsaturated nitrile monomer units is
10 to 60 wt %, preferably 20 to 50 wt %, more preferably 25 to 45
wt %. If the content of the .alpha.,.beta.-ethylenically
unsaturated nitrile monomer units is too small, the highly
saturated nitrile rubber is liable to be inferior in oil
resistance, while conversely if too large, the cold resistance may
fall.
[0021] Further, the highly saturated nitrile rubber forming the
latex of the present invention preferably contains, in addition to
the .alpha.,.beta.-ethylenically unsaturated nitrile monomer, acid
group-containing .alpha.,.beta.-ethylenically unsaturated monomer
units from the viewpoint of improvement of the adhesion and
abrasion resistance.
[0022] The acid group-containing .alpha.,.beta.-ethylenically
unsaturated monomer forming the acid group-containing
.alpha.,.beta.-ethylenically unsaturated monomer units is a monomer
containing .alpha.,.beta.-ethylenically unsaturated bonds and an
acid group in its molecule. The acid group is not particularly
limited and may be any of a carboxyl group, sulfonic acid group,
phosphoric acid group, etc., but a carboxyl group is preferable. As
the acid group-containing .alpha.,.beta.-ethylenically unsaturated
monomer, one which has 3 to 18 carbon atoms is preferable, while
one which has 3 to 9 carbon atoms is particularly preferable.
[0023] As the .alpha.,.beta.-ethylenically unsaturated monomer
having a carboxyl group, in addition to an
.alpha.,.beta.-ethylenically unsaturated monocarboxylic acid,
.alpha.,.beta.-ethylenically unsaturated dicarboxylic acid, and
.alpha.,.beta.-ethylenically unsaturated dicarboxylic acid
monoester, an .alpha.,.beta.-ethylenically unsaturated dicarboxylic
acid anhydride which is able to change to a compound having a
carboxyl group may be mentioned.
[0024] As the .alpha.,.beta.-ethylenically unsaturated
monocarboxylic acid, acrylic acid, methacrylic acid, ethacrylic
acid, crotonic acid, cinnamic acid, etc. may be mentioned.
[0025] As the .alpha.,.beta.-ethylenically unsaturated dicarboxylic
acid, maleic acid, fumaric acid, itaconic acid, citraconic acid,
chloromaleic acid, etc. may be mentioned.
[0026] As the .alpha.,.beta.-ethylenically unsaturated dicarboxylic
acid monoester, monomethyl maleate, monoethyl maleate, monobutyl
maleate, monocyclohexyl maleate, monomethyl fumarate, monoethyl
fumarate, monobutyl fumarate, mono-2-hydroxyethyl fumarate,
monocyclohexyl fumarate, monomethyl itaconate, monoethyl itaconate,
monobutyl itaconate, etc. may be mentioned.
[0027] As the .alpha.,.beta.-ethylenically unsaturated dicarboxylic
acid anhydride, maleic anhydride, itaconic anhydride, citraconic
anhydride, etc. may be mentioned.
[0028] Among these as well, an .alpha.,.beta.-ethylenically
unsaturated monocarboxylic acid is preferable, an
.alpha.,.beta.-ethylenically unsaturated monocarboxylic acid which
has 3 to 9 carbon atoms is more preferable, acrylic acid and
methacrylic acid are further preferable, and methacrylic acid is
particularly preferable.
[0029] In the highly saturated nitrile rubber forming the latex of
the present invention, the content of the acid group-containing
.alpha.,.beta.-ethylenically unsaturated monomer units is
preferably 0.1 to 20 wt %, more preferably 0.5 to 10 wt %,
particularly preferably 1 to 6 wt %. By copolymerizing the acid
group-containing .alpha.,.beta.-ethylenically unsaturated monomer
in the above range, the obtained adhesive layer can be improved in
adhesion and abrasion resistance.
[0030] Further, the highly saturated nitrile rubber forming the
latex of the present invention preferably further contains diene
monomer units and/or .alpha.-olefin monomer units from the
viewpoint of improvement of the adhesion by improving the rubbery
modulus.
[0031] As the diene monomer forming the diene monomer units,
conjugated dienes which has 4 or more carbon atoms such as
1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, and
1,3-pentadiene and nonconjugated dienes which has 5 to 12 carbon
atoms such as 1, 4-pentadiene and 1, 4-hexadiene may be mentioned.
Among these, conjugated dienes are preferable, while 1,3-butadiene
is more preferable.
[0032] As the .alpha.-olefin monomer forming the .alpha.-olefin
monomer units, one which has 2 to 12 carbon atoms is preferable.
Ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene,
1-octene, etc. may be mentioned.
[0033] In the highly saturated nitrile rubber forming the latex of
the present invention, the content of the diene monomer units
and/or .alpha.-olefin monomer units is preferably 20 to 89.9 wt %,
more preferably 40 to 79.5 wt %, particularly preferably 49 to 74
wt %.
[0034] Furthermore, the highly saturated nitrile rubber forming the
latex of the present invention may be a copolymer obtained by
further copolymerizing copolymerizable other monomer which can
copolymerize with an .alpha.,.beta.-ethylenically unsaturated
nitrile monomer, acid group-containing .alpha.,.beta.-ethylenically
unsaturated monomer, and a diene and/or .alpha.-olefin. As the
content of the units of the copolymerizable other monomer in the
highly saturated nitrile rubber, 30 wt % or less is preferable, 10
wt % or less is more is preferable, and 5 wt % or less is
particularly preferable.
[0035] As such a copolymerizable other monomer, an aromatic vinyl,
.alpha.,.beta.-ethylenically unsaturated monocarboxylic acid ester,
fluoroolefin, copolymerizable antiaging agent, etc. may be
mentioned.
[0036] As the aromatic vinyl, styrene and a styrene derivative
which has 8 to 18 carbon atoms may be mentioned. As specific
examples of the styrene derivative, .alpha.-methylstyrene,
vinylpyridine, etc. may be mentioned.
[0037] As the .alpha.,.beta.-ethylenically unsaturated
monocarboxylic acid ester, an ester of an
.alpha.,.beta.-ethylenically unsaturated monocarboxylic acid and an
aliphatic alcohol which has 1 to 12 carbon atoms may be mentioned.
As specific examples, methyl(meth)acrylate (meaning methyl acrylate
and/or methyl methacrylate, same below), butyl(meth)acrylate,
methoxyethyl (meth)acrylate, trifluoroethyl(meth)acrylate,
tetrafluoropropyl(meth)acrylate, etc. may be illustrated.
[0038] As the fluoroolefin, an unsaturated fluorine compound which
has 2 to 12 carbon atoms may be mentioned. As specific examples,
difluoroethylene, tetrafluoroethylene, fluoroethylvinyl ether,
fluoropropylvinyl ether, o-trifluoromethylstyrene, vinyl
pentafluorobenzoate, etc. may be mentioned.
[0039] As specific examples of the copolymerizable antiaging agent,
N-(4-anilinophenyl) acrylamide, N-(4-anilinophenyl)methacrylamide,
N-(4-anilinophenyl) cinnamamide, N-(4-anilinophenyl) crotonamide,
N-phenyl-4-(3-vinyl benzyloxy) aniline, N-phenyl-4-(4-vinyl
benzyloxy) aniline, etc. may be mentioned.
[0040] The highly saturated nitrile rubber of the latex forming the
present invention has a Mooney viscosity (ML.sub.1+4, 100.degree.
C.) of preferably 10 to 300, more preferably 20 to 250,
particularly preferably 30 to 200. If the Mooney viscosity is too
low, the mechanical properties of the composite obtained which is
bonded by the adhesive composition of the present invention are
liable to fall. On the other hand, if too high, the processability
may deteriorate.
[0041] Further, the highly saturated nitrile rubber forming the
latex of the present invention has an iodine value of 120 or less,
preferably 80 or less, more preferably 60 or less, particularly
preferably 30 or less. If the iodine value is too high, when an
adhesive layer is made with the latex, the obtained adhesive layer
is liable to fall in heat aging resistance or ozone resistance.
[0042] Furthermore, the highly saturated nitrile rubber forming the
latex of the present invention has a weight average molecular
weight (Mw) of the solubles in chloroform of 100,000 or less,
preferably 10,000 to 90,000, more preferably 20,000 to 80,000. If
the weight average molecular weight of the solubles in chloroform
is too large, the obtained adhesive layer ends up deteriorating in
stretchability. The weight average molecular weight of the solubles
in chloroform can, for example, be found by making the highly
saturated nitrile rubber dissolve in chloroform and measuring the
solubles of the obtained solution using gel permeation
chromatography. Note that, the molecular weight distribution
(Mw/Mn) of the solubles in chloroform is not particularly limited,
but is preferably 2 to 100, more preferably 2.5 to 50.
[0043] Note that, the method of making the weight average molecular
weight of the solubles in chloroform of the highly saturated
nitrile rubber, which forms the latex of the present invention, the
above range is not particularly limited, but, for example, when
producing the highly saturated nitrile rubber forming the latex of
the present invention by emulsion polymerization, the method of not
adding a molecular weight modifier at the time of start of
polymerization but adding a molecular weight modifier in the middle
of the emulsion polymerization may be mentioned. In such a method,
it is possible to adjust the timing when adding a molecular weight
modifier in the middle of the process and the amount of addition
when adding a molecular weight modifier in the middle of the
process so as to adjust the weight average molecular weight of the
solubles in chloroform.
[0044] Further, the latex of the present invention is one where
when removing the volatiles contained in the latex and making the
highly saturated nitrile rubber forming the latex of the present
invention a film, the properties of the film are in the ranges
explained below.
[0045] That is, in the latex of the present invention, the loss
tangent tan .delta..sub.(50.degree. C.) at 50.degree. C. when
making the highly saturated nitrile rubber forming the latex of the
present invention into a film (below, referred to as a "film
product") is 0.3 to 0.6 in range, preferably 0.3 to 0.5 in range.
The loss tangent tan .delta..sub.(50.degree. C.) at 50.degree. C.
is an indicator showing the fluidity. In particular, the effect of
the low molecular weight components is reflected. If the loss
tangent tan .delta..sub.(50.degree. C.) is too small, the
stretchability ends up deteriorating. On the other hand, if the
loss tangent tan .delta..sub.(50.degree. C.) is too large, the
obtained adhesive layer ends up falling in strength and the
abrasion resistance ends up deteriorating. Note that, the loss
tangent tan .delta..sub.(50.degree. C.) can, for example, be
measured by casting and drying the latex of the present invention
on a predetermined base material to obtain a thickness 0.1 mm to
0.6 mm highly saturated nitrile rubber film and measuring the
obtained film using a dynamic viscoelasticity measuring device.
[0046] Further, in the latex of the present invention, the complex
torque S* at the time of 100% shear strain at 100.degree. C. of the
film product is 20 dNm or less, preferably 5 to 19 dNm,
particularly preferably 10 to 19 dNm. The complex torque S* at the
time of 100% shear strain is the torque value at the time of making
the film deform relatively largely and is an indicator showing the
rigidity. If the complex torque S* at the time of 100% shear strain
is too large, the obtained adhesive layer ends up becoming to hard
to deform and the stretchability ends up deteriorating. Note that,
the complex torque S* at the time of 100% shear strain can, for
example, be measured by casting and drying the latex of the present
invention on a predetermined base material to obtain a thickness
0.1 mm to 0.7 mm highly saturated nitrile rubber film and measuring
the obtained film under conditions of a dynamic shear strain of
100% and measurement temperature of 100.degree. C. using a dynamic
viscoelasticity measuring device.
[0047] Note that, the method of making the loss tangent tan
.delta..sub.(50.degree. C.) and complex torque S* at the time of
100% shear strain the above ranges is not particularly limited, but
when producing the highly saturated nitrile rubber forming the
latex of the present invention by emulsion polymerization, the
method of not adding the molecular weight modifier at the time of
start of polymerization, but adding the molecular weight modifier
in the middle of the emulsion polymerization may be mentioned.
[0048] Further, in the latex of the present invention, in addition
to the loss tangent tan .delta..sub.(50.degree. C.) and complex
torque S* at the time of 100% shear strain of the film product
being in the above ranges, the following requirements are
preferably also satisfied. Due to this, the obtained adhesive layer
can be further improved in stretchability and abrasion
resistance.
[0049] That is, in the present invention, the difference .DELTA.
tan .delta.=tan .delta..sub.(150.degree. C.)-tan
.delta..sub.(50.degree. C.), which is a difference between the loss
tangent tan .delta..sub.(50.degree. C.) at 50.degree. C. and the
loss tangent tan .delta..sub.(150.degree. C.) at 150.degree. C. of
the film product, is preferably 0.35 or less, more preferably 0.1
to 0.3. Note that, the loss tangent tan .delta..sub.(150.degree.
C.) at 150.degree. C. can be measured in the same way as the above
loss tangent tan .delta..sub.(50.degree. C.) at 50.degree. C.
[0050] Further, in the present invention, the storage modulus G'
.sub.(100.degree. C.) at 100.degree. C. of the film product is
preferably 200 kPa or less, more preferably 50 to 150 kPa. Note
that, the storage modulus G' .sub.(100.degree. C.) at 100.degree.
C. is an indicator showing the hardness. For example, by casting
and drying the latex of the present invention on a predetermined
base material, it is possible to obtain a thickness 0.1 mm to 0.6
mm highly saturated nitrile rubber film and the storage modulus G'
.sub.(100.degree. C.) at 100.degree. C. can be measured by
measuring the obtained film using a dynamic viscoelasticity
measuring device.
[0051] Furthermore, in the present invention, the difference
.DELTA.G'=G' .sub.(50.degree. C.)-G' .sub.(150.degree. C.) which is
a difference between the storage modulus G' .sub.(50.degree. C.) at
50.degree. C. and the storage modulus G' .sub.(150.degree. C.) at
150.degree. C. of the film product is preferably 350 kPa or less,
more preferably 150 to 310 kPa. Note that, the storage modulus G'
.sub.(50.degree. C.) at 50.degree. C. and the storage modulus G'
.sub.(150.degree. C.) at 150.degree. C. of the film product can be
measured in the same way as the above-mentioned the storage modulus
G' .sub.(100.degree. C.) at 100.degree. C.
[0052] The highly saturated nitrile rubber forming the latex of the
present invention is obtained by copolymerizing the above-mentioned
monomers and, if necessary, hydrogenating the carbon-carbon double
bonds in the obtained copolymer. The polymerization method is not
particularly limited and may be the known emulsion polymerization
method or solution emulsion method, but from the viewpoint of the
industrial productivity, the emulsion polymerization method is
preferable. At the time of emulsion polymerization, a normally used
polymerization auxiliary material such as an emulsifier,
polymerization initiator, molecular weight modifier etc. can be
used.
[0053] The emulsifier is not particularly limited, but, for
example, a nonionic emulsifier such as a polyoxyethylene alkyl
ether, polyoxyethylene alkyl phenol ether, polyoxyethylene alkyl
ester, and polyoxyethylene sorbitan alkyl ester; an anionic
emulsifier such as a salt of a fatty acid such as myristic acid,
palmitic acid, oleic acid, and linoleic acid, an alkyl benzene
sulfonate such as sodium dedecylbenzene sulfonate, a higher alcohol
sulfuric acid ester salt, and an alkyl sulfosuccinate; a
copolymerizable emulsifier such as a sulfo ester of
.alpha.,.beta.-unsaturated carboxylic acid, a sulfate ester of
.alpha.,.beta.-unsaturated carboxylic acid, a sulfoalkylaryl ether;
etc. may be mentioned. The amount of the emulsifier used is
preferably 0.1 to 10 parts by weight with respect to 100 parts by
weight of the monomers used for the polymerization, more preferably
0.5 to 8 parts by weight, particularly preferably 1 to 5 parts by
weight.
[0054] The polymerization initiator is not particularly limited so
long as a radical initiator, but an inorganic peroxide such as
potassium persulfate, sodium persulfate, ammonium persulfate,
potassium perphosphate, and hydrogen perchlorate; an organic
peroxide such as t-butyl peroxide, cumen hydroperoxide, p-mentane
hydroperoxide, di-t-butyl peroxide, t-butylcumyl peroxide, acetyl
peroxide, isobutyryl peroxide, octanoyl peroxide, dibenzoyl
peroxide, 3,5,5-trimethylhexanoyl peroxide, and t-butyl
peroxyisobutyrate; an azo compound such as azobisisobutyronitrile,
azobis-2,4-dimethylvaleronitrile, azobiscyclohexane carbonitrile,
and methyl azobis isobutyrate; etc. may be mentioned. These
polymerization initiators can be used as single types alone or as a
plurality of types. As the polymerization initiator, an inorganic
or organic peroxide is preferable. When using a peroxide as a
polymerization initiator comprised, it may be combined with a
reducing agent such as sodium bisulfate or ferric sulfate and may
be used as a redox type polymerization initiator. The amount of the
polymerization initiator used is preferably 0.01 to 2 parts by
weight with respect to 100 parts by weight of the monomers used for
the polymerization.
[0055] Further, in the present invention, when copolymerizing the
above-mentioned monomers by the emulsion polymerization method, it
is preferable not to add the molecular weight modifier at the time
of start of the emulsion polymerization, but to add the molecular
weight modifier, after starting the emulsion polymerization, at the
stage of a 5 to 60 wt % polymerization conversion rate. Due to
this, in the obtained highly saturated nitrile rubber, it is
possible to make the weight average molecular weight of the
solubles in chloroform, loss tangent tan .delta..sub.(50.degree.
C.), and complex torque S* at the time of 100% shear strain the
above ranges.
[0056] That is, for example, when making the latex of the highly
saturated nitrile rubber of the present invention one containing
.alpha.,.beta.-ethylenically unsaturated nitrile monomer units,
acid group-containing .alpha.,.beta.-ethylenically unsaturated
monomer units, and diene monomer units and/or .alpha.-olefin
monomer units, it is preferable adopt a mode starting the emulsion
polymerization of the monomer mixture containing the
.alpha.,.beta.-ethylenically unsaturated nitrile monomer, acid
group-containing .alpha.,.beta.-ethylenically unsaturated monomer,
diene monomer and/or .alpha.-olefin monomer without adding the
molecular weight modifier, then, at the stage reaching a 5 to 60 wt
% polymerization conversion rate, adding a later explained
predetermined amount of a molecular weight modifier and continuing
the emulsion polymerization.
[0057] The timing of adding the molecular weight modifier in the
middle of the process is preferably a stage after starting emulsion
polymerization when the polymerization conversion rate becomes 5 to
60 wt %, more preferably a stage when it becomes 15 to 45 wt %.
Note that, the method of addition when adding the molecular weight
modifier in the middle of the process is not particularly limited.
The method of adding the molecular weight modifier to be added all
at once or the method of adding it divided into several batches may
be used. Note that, in the present invention, the molecular weight
modifier is preferably added after the start of the emulsion
polymerization in the middle of the emulsion polymerization and it
is preferable not to add the molecular weight modifier at the time
of start of emulsion polymerization, but it is sufficient to
establish a state where no molecular weight modifier is
substantially contained at the time of start of emulsion
polymerization. For example, if 10 weight ppm or less, a compound
acting as a molecular weight modifier may be included.
[0058] The molecular weight modifier is not particularly limited,
but mercaptans such as t-dodecyl mercaptan, n-dodecyl mercaptan,
and octyl mercaptan; halogenated hydrocarbons such as carbon
tetrachloride, methylene chloride, and methylene bromide; a
.alpha.-methylstyrene dimer; sulfur-containing compounds such as
tetraethylthiuram disulfide, dipentamethylenethiuram disulfide, and
diisopropyl xantogen disulfide may be mentioned. These can be used
as single types alone or as a plurality of types. Among these as
well, a mercaptan is preferable, while t-dodecyl mercaptan is more
preferable. The amount of use of the molecular weight modifier is
preferably 1 to 3 parts by weight with respect to 100 parts by
weight of the monomers used for the polymerization, more preferably
1 to 2 parts by weight.
[0059] For the medium of the emulsion polymerization, usually water
is used. The amount of water is preferably 80 to 500 parts by
weight with respect to 100 parts by weight of the monomers used for
the polymerization, more preferably 80 to 300 parts by weight.
[0060] At the time of emulsion polymerization, further, in
accordance with need, a polymerization auxiliary material such as a
stabilizer, dispersant, pH adjuster, deoxidant, or particle size
adjuster can be used. When using these, the types and amounts of
use are not particularly limited.
[0061] Note that, the temperature of the emulsion polymerization is
preferably 0 to 80.degree. C., particularly preferably 0 to
30.degree. C.
[0062] The latex of the highly saturated nitrile rubber of the
present invention is preferably obtained by hydrogenating the latex
of the nitrile rubber obtained by emulsion polymerization. Note
that, when the amount of the conjugated diene monomer units in the
nitrile rubber is small and, for this reason, the iodine value of
the nitrile rubber obtained by the emulsion polymerization is the
above-mentioned value or less, there is no need to perform the
hydrogenation treatment.
[0063] The average particle size of the thus obtained latex is
preferably 0.01 to 0.5 .mu.m. Further, the solid content
concentration of the latex is preferably 60 wt % or less for
preventing agglomeration, more preferably 5 to 60 wt %,
particularly preferably 10 to 50 wt %.
[0064] The hydrogenation may be performed by a known method. The
hydrogenation may be performed by a known method. The oil layer
hydrogenation method of coagulating the latex of nitrile rubber
obtained by emulsion polymerization, then hydrogenating it by an
oil layer, and the aqueous layer hydrogenation method of
hydrogenating the latex obtained by polymerization as it is, etc.
may be mentioned. Among these, the aqueous layer hydrogenation
method is preferred.
[0065] At the time of hydrogenation of the nitrile rubber by the
aqueous layer hydrogenation method, it is preferable to dilute a
latex of nitrile rubber prepared by emulsion polymerization by
adding water as needed and hydrogenate it. As the aqueous layer
hydrogenation method, there are the aqueous layer direct
hydrogenation method of hydrogenation by supplying hydrogen to a
reaction system in the presence of a hydrogenation catalyst and the
aqueous layer indirect hydrogenation method of hydrogenation by
reduction in the presence of an oxidizing agent, reducing agent,
and activating agent, but the aqueous layer direct hydrogenation
method is more preferable.
[0066] The hydrogenation catalyst used for the aqueous layer direct
hydrogenation method is not particularly limited so long as a
compound which is difficult to break down in water, but, for
example, a palladium catalyst etc. may be mentioned. As specific
examples of the palladium catalyst, a palladium salt of a
carboxylic acid such as formic acid, acetic acid, propionic acid,
lauric acid, succinic acid, oleic acid, and phthalic acid; a
chlorinated palladium such as palladium chloride,
dichloro(cyclooctadiene)palladium,
dichloro(norbornadiene)palladium, and ammonium hexachloropalladate
(IV); an iodated palladium such as palladium iodide; palladium
sulfate dehydrate, etc. may be mentioned. Among these as well, a
palladium salt of a carboxylic acid,
dichloro(norbornadiene)palladium, and ammonium
hexachloropalladate(IV) are particularly preferable. The amount of
use of a hydrogenation catalyst may be suitably determined, but is
preferably 5 to 10,000 weight ppm with respect to the nitrile
rubber before hydrogenation, more preferably 10 to 5,000 weight
ppm.
[0067] The reaction temperature in the aqueous layer direct
hydrogenation method is preferably 0 to 300.degree. C., more
preferably 20 to 150.degree. C., particularly preferably 30 to
100.degree. C. If the reaction temperature is too low, the reaction
speed is liable to fall, while conversely if the reaction
temperature is too high, there is a possibility of a secondary
reaction such as hydrogenation of a nitrile group occurring.
[0068] The hydrogen pressure is preferably 0.1 to 30 MPa, more
preferably 0.5 to 20 MPa. The reaction time is preferably 1 to 15
hours, particularly preferably 2 to 10 hours.
[0069] In the aqueous layer direct hydrogenation method, after the
end of the hydrogenation reaction, usually the hydrogenation
catalyst in the latex is removed. As the method of removal of the
hydrogenation catalyst, for example, the method of adding an
adsorbent such as activated carbon or an ion exchange resin to the
latex after the end of the hydrogenation reaction and stirring so
that the hydrogenation catalyst is adsorbed at the adsorbent, then
separating the latex by filtration or centrifugation can be used.
Further, it is also possible to add hydrogen perchlorate and
dimethylglyoxime to the latex after the end of the hydrogenation
reaction, adjust the pH to 8 to 11, and warm the mixture while
stirring to make the hydrogenation catalyst precipitate as
insolubles in the latex and remove the same. Note that, in the
aqueous layer direct hydrogenation method, the hydrogenation
catalyst need not be removed and may be left in the latex.
[0070] Adhesive Composition
[0071] The adhesive composition of the present invention contains
the above-mentioned latex of a highly saturated nitrile rubber of
the present invention.
[0072] In the adhesive composition of the present invention, the
content of the highly saturated nitrile rubber (solid content) is
preferably 5 to 50 wt %, particularly preferably 10 to 40 wt %.
[0073] The adhesive composition of the present invention preferably
further contains an adhesive resin in addition to the
above-mentioned latex of a highly saturated nitrile rubber of the
present invention.
[0074] As the adhesive resin, a resorcinol formaldehyde resin,
melamine resin, epoxy resin, and isocyanate resin may be suitably
used, but among these, a resorcinol formaldehyde resin is
preferable. As the resorcinol formaldehyde resin, a known one (for
example, one disclosed in Japanese Patent Publication No.
55-142635A) can be used. The reaction ratio of the resorcine and
formaldehyde is, by molar ratio of "resorcine:formaldehyde",
normally 1:1 to 1:5, preferably 1:1 to 1:3.
[0075] The resorcinol formaldehyde resin is used in, based on dry
weight, a ratio of preferably 5 to 30 parts by weight with respect
to 100 parts by weight of the solid content of the above-mentioned
latex of a highly saturated nitrile rubber of the present
invention, more preferably 8 to 20 parts by weight. If the amount
of the resorcinol formaldehyde resin is excessively large, the
adhesive layer becomes too hard and the flexibility is impaired.
Due to this, the composite obtained using the adhesive composition
of the present invention sometimes falls in abrasion
resistance.
[0076] Further, to further enhance the bonding strength of the
adhesive composition of the present invention, in accordance with
need, the conventionally used 2, 6-bis(2,
4-dihydroxyphenylmethyl)-4-chlorophenol or a similar compound,
isocyanate, block isocyanate, ethylene urea, polyepoxide, modified
polyvinyl chloride resin, etc. may be jointly used.
[0077] Furthermore, the adhesive composition of the present
invention may contain a vulcanization aid. By a vulcanization aid
being included, the composite obtained by using the adhesive
composition of the present invention can be improved in mechanical
strength. As the vulcanization aid, quinone dioximes such as
p-quinone dioximes; methacrylic acid esters such as lauryl
methacrylate or methyl methacrylate; allyl compounds such as TAC
(triallyl cyanurate) and TAIC (triallyl isocyanurate); maleimide
compounds such as bismaleimide, phenyl maleimide, N,N-m-phenylene
dimaleimide, 4,4'-diphenylmethane bismaleimide, bisphenol A
diphenylether bismaleimide,
3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, and
N,N'-(4-methyl-1,3-phenylene)bis(maleinimide); allyl esters of
polyhydric acids such as DAF (diallyl fumarate), DAP (diallyl
phthalate), diallyl maleate, diallyl sebacate, and triallyl
phosphate; diethylene glycol bisallyl carbonate; allyl ethers such
as ethylene glycol diallyl ether, a triallyl ether of
trimethylolpropane, and a partial allyl ether of pentaerythritol;
allyl modified resins such as allylated novolac, allylated resol
resin; tri- to pentafunctional methacrylate compounds or acrylate
compounds such as trimethylolpropane trimethacrylate and
trimethylolpropane triacrylate; sulfur; etc. may be mentioned.
[0078] Fiber Base Material-Highly Saturated Nitrile Rubber
Composite
[0079] As a composite obtained by bonding by the adhesive
composition of the present invention, for example, a fiber base
material-highly saturated nitrile rubber composite including a
fiber base material and a highly saturated nitrile rubber may be
mentioned. Such a fiber base material-highly saturated nitrile
rubber composite can normally be obtained by bonding a fiber base
material and highly saturated nitrile rubber by the above-mentioned
adhesive composition of the present invention.
[0080] Note that, below, the highly saturated nitrile rubber
contained in the latex forming the adhesive composition of the
present invention will be explained as the "adhesive highly
saturated nitrile rubber" and the highly saturated nitrile rubber
forming the rubber layer of the fiber base material-highly
saturated nitrile rubber composite will be explained as the
"adherend highly saturated nitrile rubber".
[0081] The form of the fiber base material-highly saturated nitrile
rubber composite is not particularly limited. It is sufficient that
it be one where an adhesive layer formed using the above-mentioned
adhesive composition of the present invention is used to bond the
fiber base material and adherend highly saturated nitrile rubber
together. In particular, one comprised of a fiber base material and
adherend highly saturated nitrile rubber bonded together, one
comprised of an adherend highly saturated nitrile rubber in which
part or all of the fiber base material is embedded, etc. may be
mentioned.
[0082] The type of the fiber forming the fiber base material is not
particularly limited. As specific examples, vinylon fiber,
polyester fiber, polyamide fiber such as nylon and aramide
(aromatic polyamide), PBO fiber, fluorine-based fiber, glass fiber,
carbon fiber, cotton, rayon, etc. may be mentioned. These are
suitably selected according to the application. The shape of the
fiber base material is not particularly limited. As specific
examples, staple fibers, filaments, cords, ropes, woven fabrics
(canvas etc.) and the like may be mentioned. This may be suitably
selected in accordance with the application of the fiber base
material-highly saturated nitrile rubber composite. For example, it
is possible to use a fiber base material of a cord form to make a
toothed belt made of the highly saturated nitrile rubber containing
core yarns or possible to use a fiber base material of a base
fabric form such as canvas to make a toothed belt made of the
highly saturated nitrile rubber covered with a base fabric.
[0083] The adherend highly saturated nitrile rubber used for the
fiber base material-highly saturated nitrile rubber composite is a
copolymer obtained by using a conjugated diene and
.alpha.,.beta.-ethylenically unsaturated nitrile as essential
component monomers, if necessary, copolymerizing these essential
component monomers with copolymerizable monomers, and hydrogenating
the obtained copolymer according to need. As the copolymerizable
monomers, ones similar to the above-mentioned adhesive highly
saturated nitrile rubber can be mentioned.
[0084] As specific examples of the adherend highly saturated
nitrile rubber, a highly saturated butadiene-acrylonitrile
copolymer rubber, carboxyl group-containing highly saturated
butadiene-acrylonitrile copolymer rubber, highly saturated
isoprene-butadiene-acrylonitrile copolymer rubber, highly saturated
isoprene-acrylonitrile copolymer rubber, highly saturated
butadiene-acrylate methyl-acrylonitrile copolymer rubber, highly
saturated butadiene-acrylate-acrylonitrile copolymer rubber, highly
saturated butadiene-ethylene-acrylonitrile copolymer rubber, butyl
acrylate-ethoxyethyl acrylate-vinyl norbornene-acrylonitrile
copolymer rubber, etc. may be mentioned. Among these, in
particular, when using a fiber base material-highly saturated
nitrile rubber composite for automobile use, highly saturated
butadiene-acrylonitrile copolymer rubber is preferable from the
viewpoint of oil resistance and heat resistance.
[0085] The hydrogenation rate of the adherend highly saturated
nitrile rubber is, by iodine value, 120 or less, preferably 100 or
less, more preferably 80 or less. If the iodine value is too high,
the obtained fiber base material-highly saturated nitrile rubber
composite is liable to fall in heat resistance.
[0086] The content of the acrylonitrile monomer units of the
adherend highly saturated nitrile rubber is preferably 10 to 60 wt
%, more preferably 12 to 55 wt %, particularly preferably 15 to 50
wt %. If the content of the acrylonitrile monomer units is too
small, the fiber base material-highly saturated nitrile rubber
composite is liable to deteriorate in oil resistance, while
conversely if the content of the acrylonitrile monomer units is too
large, the cold resistance may fall.
[0087] Further, the Mooney viscosity (ML.sub.1+4, 100.degree. C.)
of the adherend highly saturated nitrile rubber is preferably 10 to
300, more preferably 20 to 250, particularly preferably 30 to 200.
If the Mooney viscosity is too low, the shapeability and mechanical
properties are liable to fall, while if the Mooney viscosity is too
high, the shapeability may fall.
[0088] The adherend highly saturated nitrile rubber may have
suitably added to it a cross-linking agent such as sulfur, a
peroxide-based cross-linking agent, or a polyamine-based
cross-linking agent and also compounding agents usually blended in
when processing rubber such as a filler such as carbon black,
silica, and staple fibers; a cross-linking accelerator; antiaging
agent; plasticizer; pigment; tackifier; processing aid; scorch
retarder; or silane coupling agent.
[0089] The method of obtaining the fiber base material-highly
saturated nitrile rubber composite is not particularly limited,
but, for example, the method of using immersion etc. to deposit the
above-mentioned adhesive composition of the present invention on a
fiber base material, place this on the adherend highly saturated
nitrile rubber, and heat and press this can be illustrated.
[0090] The pressing operation can be performed by using a
press-forming machine, metal rolls, an injection molding machine,
etc. The pressure of the pressing operation is preferably 0.5 to 20
MPa, more preferably 2 to 10 MPa, the heating temperature is
preferably 130 to 300.degree. C., more preferably 150 to
250.degree. C., and the operation time is preferably 1 to 180
minutes, more preferably 5 to 120 minutes.
[0091] By this method, the adherend highly saturated nitrile rubber
can be vulcanized and shaped and the fiber base material and
adherend highly saturated nitrile rubber can be bonded
simultaneously.
[0092] Note that, in this case, the inside surface of the die of
the press or the surface of the roll may be formed with a shape for
realizing the target surface shape so that the adherend highly
saturated nitrile rubber forming the fiber base material-highly
saturated nitrile rubber composite is given a desired surface
shape.
[0093] Further, as one form of the fiber base material-highly
saturated nitrile rubber, a fiber base material-highly saturated
nitrile rubber-fiber base material composite can be mentioned. The
fiber base material-highly saturated nitrile rubber-fiber base
material composite is, for example, a combination of a fiber base
material (the fiber base material may be composite of two or more
types of fiber base materials) and a fiber base material-highly
saturated nitrile rubber composite. The fiber base material-highly
saturated nitrile rubber-fiber base material composite can, for
example, be obtained by depositing the adhesive composition of the
present invention on a fiber base material comprised of core yarns
and a base fabric comprised of a fiber base material and stacking
and hot pressing core yarns on which the adhesive composition is
deposited, the highly saturated nitrile rubber to be adhered, and
the fiber base material on which the adhesive composition is
deposited.
[0094] The fiber base material treated by the adhesive composition
of the present invention is excellent in abrasion resistance and
dynamic fatigue resistance. Further, the adherend highly saturated
nitrile rubber is excellent in oil resistance, heat resistance,
etc., so the fiber base material-highly saturated nitrile rubber
composite obtained using the adhesive composition of the present
invention is suitable for use as members contacting oil in
automobiles, in particular, as belts, flat belts, V-belts, V-ribbed
belts, round belts, corner belts, toothed belts, in-oil belts,
etc.
[0095] Further, the fiber base material-highly saturated nitrile
rubber composite obtained using adhesive composition of the present
invention can be suitably used for hoses, tubes, diaphragms, etc.
As hoses, single-tube rubber hoses, multilayer rubber hoses,
braided type reinforced hoses, wrapped type reinforced hoses, etc.
may be mentioned. As diaphragms, flat type diaphragms, rolling type
diaphragms, etc. may be mentioned.
[0096] The fiber base material-highly saturated nitrile rubber
composite obtained by using the adhesive composition of the present
invention can be used as industrial products such as seals and
rubber rolls in addition to the above application. As seals, seals
for moving parts such as rotating, rocking, and reciprocating parts
and seals for fixed parts may be mentioned. As moving part seals,
oil seals, piston seals, mechanical seals, boots, dust covers,
diaphragms, accumulators, etc. may be mentioned. As fixed part
seals, O-rings, various types of gaskets, etc. may be mentioned. As
rubber rolls, rolls used as parts of office automation equipment
such as printers and copiers; fiber processing rolls such as
spinning-use draw rolls and spinning-use draft rolls; ironmaking
rolls such as bridle rolls, snapper rolls, and steering rolls; etc.
may be mentioned.
EXAMPLES
[0097] Below, examples and comparative examples will be given to
specifically explain the present invention. Below, "parts" are
based on weight unless otherwise indicated. Note that, the tests
and evaluations were conducted by on the following method.
[0098] Iodine Value
[0099] An excess amount of methanol was added to a latex of the
highly saturated nitrile rubber and the precipitated rubber was
taken out and dried under reduced pressure at 60.degree. C. for 24
hours to thereby obtain highly saturated nitrile rubber. Further,
the obtained highly saturated nitrile rubber was used for
measurement in accordance with JIS K 6235.
[0100] Weight Average Molecular Weight Mw of Chloroform
Solubles
[0101] A latex of the highly saturated nitrile rubber was cast on a
glass sheet and dried by allowing it to stand at 20.degree. C. for
72 hours. Further, the film formed by drying was peeled off from
the glass sheet. The peeled off film was further dried under
reduced pressure at 60.degree. C. for 24 hours to thereby obtain a
thickness approximately 0.3 ram highly saturated nitrile rubber
film (film product). This film was immersed in chloroform and
allowed to stand there at 25.degree. C. for 48 hours to make it
dissolve, then the result was passed through a membrane filter
(pore size 0.5 .mu.m), then was measured by gel permeation
chromatography under the following conditions to obtain the weight
average molecular weight Mw of the chloroform soluble. Note that,
Mw is converted to standard polystyrene.
[0102] Measuring device: HLC-8220 (made by Toso)
[0103] Column: two columns of product name "GMH-HR-H" (made by
Toso) and one column of product name "G3000H-HR" (made by Toso)
connected in series.
[0104] Detector:refractive index detector
[0105] Eluent: chloroform
[0106] Column temperature: 40.degree. C.
[0107] Loss Tangent tan .delta. and Storage Modulus G'
[0108] The same procedure was followed as in the above measurement
of the weight average molecular weight and molecular weight
distribution to obtain a film of the highly saturated nitrile
rubber of a thickness of approximately 0.3 mm (film product).
Further, the obtained film was used for measurement using a dynamic
viscoelasticity measuring device: product name "RPA2000" (made by
Alpha Technologies). The film was cut into pieces matching the die
shape and superposed to about 5 g. It was measured at a dynamic
shear strain 6.98%, frequency 1.7 Hz for loss tangents tan
.delta..sub.(50.degree. C.) at 50.degree. C., tan
.delta..sub.(100.degree. C.) at 100.degree. C., tan
.delta..sub.(150.degree. C.) at 150.degree. C. and storage modulus
G' .sub.(50.degree. C.) at 50.degree. C., G' .sub.(100.degree. C.)
at 100.degree. C., and G' .sub.(150.degree. C.) at 150.degree. C.
Furthermore, .DELTA. tan .delta. and .DELTA.G' were found in the
following formulas:
.DELTA. tan .delta.=(tan .delta..sub.(150.degree. C.) at
150.degree. C.)-(tan .delta..sub.(50.degree. C.) at 50.degree.
C.)
.DELTA.G'=(G' .sub.(50.degree. C.) at 50.degree. C.)-(G'
.sub.(150.degree. C.) at 150.degree. C.)
[0109] Complex Torque S* at Time of 100% Shear Strain
[0110] The same procedure was followed as in the above measurement
of the weight average molecular weight to obtain a film of the
highly saturated nitrile rubber of a thickness of approximately 0.3
mm (film product). Further, the obtained film was used for
measurement using a dynamic viscoelasticity measuring device:
product name "RPA2000" (made by Alpha Technologies). The film was
cut into pieces matching the die shape and superposed to about 5 g.
It was measured at a dynamic shear strain 100%, frequency 1 Hz, and
100.degree. C. for complex torque S* at time of 100% shear strain
at 100.degree. C.
[0111] Tensile Test of Adhesive Composition-Treated Fiber Base
Material
[0112] The adhesive composition-treated nylon base material was cut
into a strip of a width of 2.5 cm and length of 10 cm to obtain a
test piece. A tensile tester was used to conduct a tensile test on
this strip-shaped test piece at 50 mm/min in speed. In this test,
the distance between the chucks at the time of start of the test
was made 4.4 am. The time when the distance between the chucks
became 6.6 an was deemed 50% stress. The load at this time was
found. The lower this load, the easier it is for the adhesive
composition-treated fiber base material to deform, the easier it is
to form a complicated fiber-rubber composite, and the better the
stretchability.
[0113] Abrasion Resistance Test of Fiber Base Material-Highly
Saturated Nitrile Rubber Composite
[0114] A fiber base material-highly saturated nitrile rubber
composite was tested for abrasion resistance using a carpet-use
taber abrasion tester. The test was conducted under conditions of a
load of 1 kg, an abraded surface temperature of 120.degree. C. (by
irradiation by infrared lamp), and a disk rotation speed of 10,000.
The criteria for evaluation were as follows: The higher the value
of the evaluation criteria, the better the abrasion resistance.
[0115] 5: Abrasion not observed or abrasion observed, but in 25% or
less of surface area of nylon
[0116] 4: Abrasion observed in more than 25%, 50% or less in range
of surface area of nylon base material
[0117] 3: Abrasion observed in more than 50%, 75% or less in range
of surface area of nylon base material
[0118] 2: Abrasion observed in more than 75%, 90% or less in range
of surface area of nylon base material
[0119] 1: Abrasion observed in more than 90% in range of surface
area of nylon base material
Example 1
Production of Latex (L1) of the Highly Saturated Nitrile Rubber
(A1)
[0120] To a reactor, 180 parts of ion exchange water, 25 parts of
concentration 10 wt % sodium dedecylbenzene sulfonate aqueous
solution, 35 parts of acrylonitrile, and 4 parts of methacrylic
acid were charged in that order. The inside gas was replaced with
nitrogen 3 times, then the inside was charged with 61 parts of
1,3-butadiene. The reactor was held at 10.degree. C., 0.1 part of
cumen hydroperoxide (polymerization initiator) was charged, the
polymerization reaction was made to start, and the mixture was
stirred while continuing the polymerization reaction. When the
polymerization conversion rate reached 20%, 1.5 parts of t-dodecyl
mercaptan (molecular weight modifier) was added and the
polymerization reaction further continued. When the polymerization
conversion rate became 90%, 0.1 part of concentration 10 wt %
hydroquinone aqueous solution (polymerization terminator) was added
to stop the polymerization reaction. Next, at a water temperature
of 60.degree. C., the residual monomer was removed to obtain a
latex of nitrile rubber (X1) (solid content concentration about 30
wt %).
[0121] Further, in an autoclave, the latex of the nitrile rubber
(X1) and a palladium catalyst (solution of 1 wt % palladium acetate
acetone solution and equal weight of ion exchange water mixed
together) were added so that the palladium content with respect to
the dry weight of rubber contained in the latex of the above
obtained nitrile rubber (X1) became 1,000 weight ppm. The mixture
was hydrogenated by reaction at a hydrogen pressure of 3 MPa and a
temperature of 50.degree. C. for 6 hours. Then, a latex (L1) of the
highly saturated nitrile rubber (A1) (solid content concentration
30 wt %) was obtained by adjusting the solid content concentration
of the hydrogenated mixture.
[0122] The ratios of content of the monomer units of the highly
saturated nitrile rubber (A1) were found by .sup.1H-NMR
measurement, whereupon they were 34.2 wt % of acrylonitrile units,
3.3 wt % of methacrylic acid units, and 62.5 wt % of 1,3-butadiene
units (including hydrogenated parts as well). Further, the iodine
value was 28. Further, in accordance with the above methods, the
weight average molecular weight Mw of the chloroform soluble, loss
tangent tan .delta., storage modulus G', and complex torque S* at
the time of 100% shear strain were measured. Further, the .DELTA.
tan .delta. and the .DELTA.G' were found by calculation. The
results are shown in Table 1.
[0123] Preparation of Adhesive Composition 6.5 parts of resorcine,
9.4 parts of formaldehyde (concentration 37%), and 3 parts of
sodium hydroxide (concentration 10%) were dissolved in 139.6 parts
of water and reacted at 25.degree. C. for 6 hours to obtain a
resorcinol formaldehyde resin solution (RF solution).
[0124] Further, to 60.9 parts of the latex (L1) of the highly
saturated nitrile rubber (A1) (solid content concentration 30%)
which is above produced, 27.7 parts of the resorcinol formaldehyde
resin solution (RF solution) which is above prepared and 11.4 parts
of distilled water were added. The mixture was stirred at room
temperature for 1 minute, then was aged at 25.degree. C. for 24
hours to thereby obtain an adhesive composition (LS1).
[0125] Preparation of Adhesive Composition-Treated Fiber Base
Material
[0126] A fiber base material comprised of a base fabric made of
nylon 66 was dipped in the above obtained adhesive composition
(LS1) and pulled up to thereby coat the base fabric with the
adhesive composition. At this time, the rubber in the adhesive
composition was deposited to 20 parts with respect to 100 parts of
the base fabric of nylon 66. Next, the base fabric coated with the
adhesive composition was heated by an air-circulation type oven at
110.degree. C. for 10 minutes, then heated at 150.degree. C. for 3
minutes to make it cure and thereby obtain an adhesive
composition-treated fiber base material (adhesive
composition-treated nylon base material). Further, the obtained
adhesive composition-treated fiber base material was tested for
tensile strength in accordance with the above method. The results
are shown in Table 1.
[0127] Preparation of Fiber Base Material-Highly Saturated Nitrile
Rubber Composite
[0128] Further, separate from the above, to 400 parts of the
adhesive composition (LS1) which is above obtained, 40 parts of an
aqueous dispersion of HAF carbon (product name "Seast 3", made by
Tokai Carbon) (25 wt % concentration) was added to obtain an HAF
carbon mixture, then a fiber base material comprised of a base
fabric made of nylon 66 was dipped in the obtained HAF carbon
mixture and pulled up to thereby coat the base fabric with the
adhesive composition. At this time, the rubber in the adhesive
composition was deposited to 20 parts with respect to 100 parts of
the base fabric of nylon 66. Next, the base fabric coated with the
adhesive composition was heated by an air-circulation type oven at
150.degree. C. for 3 minutes to obtain a base fabric pretreated by
an adhesive composition.
[0129] Next, the rubber formulation prepared by kneading each
formulation described in Table 2 by a Bambury mixer for 15 minutes
was placed on the base fabric 15 cm.times.15 cm pretreated with the
above obtained adhesive composition, spread by rolls to a thickness
of 1 mm, then pressed by a press by a pressure of 0.1 MPa and
temperature of 160.degree. C. for 30 minutes to thereby obtain a
fiber base material-highly saturated nitrile rubber composite
(nylon base material-rubber composite). Further, the obtained fiber
base material-highly saturated nitrile rubber composite was tested
for abrasion resistance in accordance with the above method. The
results are shown in Table 1.
Example 2
[0130] Except for changing the temperature of the polymerization
reactor from 10.degree. C. to 15.degree. C. and changing the amount
of addition of t-dodecyl mercaptan at the point of time when the
polymerization conversion rate reached 20% from 1.5 parts to 1.2
parts, the same procedure was followed as in Example 1 to obtain a
latex (L2) of the highly saturated nitrile rubber (A2) (solid
content concentration 30 wt %).
[0131] The ratios of content of the monomer units of the highly
saturated nitrile rubber (A2) were 33.5 wt % of acrylonitrile
units, 3.5 wt % of methacrylic acid units, and 63.0 wt % of
1,3-butadiene units (including hydrogenated parts as well), and the
iodine value was 37. Further, the same procedure was followed as in
Example 1 for performing the different measurements. The results
are shown in Table 1.
[0132] Further, except for using, instead of the latex (L1) of the
highly saturated nitrile rubber (A1), the above obtained latex (L2)
of the highly saturated nitrile rubber (A2), the same procedure was
followed as in Example 1 to obtain an adhesive composition,
adhesive composition-treated fiber base material, and fiber base
material-highly saturated nitrile rubber composite and the same
procedure was followed to evaluate them. The results are shown in
Table 1.
Example 3
[0133] Except for changing the timing of addition of 1.5 parts of
t-dodecyl mercaptan to from the point of time when the
polymerization conversion rate reached 20% to the point of time
when the polymerization conversion rate reached 40%, the same
procedure was followed as in Example 1 to obtain a latex (L3) of
the highly saturated nitrile rubber (A3) (solid content
concentration 30 wt %). The ratios of content of the monomer units
of the highly saturated nitrile rubber (A3) were 33.8 wt % of
acrylonitrile units, 3.5 wt % of methacrylic acid units, and 62.7
wt % of 1,3-butadiene units (including hydrogenated parts as well),
and the iodine value was 45. Further, the same procedure was
followed as in Example 1 for performing the different measurements.
The results are shown in Table 1.
[0134] Further, except for using the latex (L1) of the highly
saturated nitrile rubber (A1), the above obtained latex (L3) of the
highly saturated nitrile rubber (A3), the same procedure was
followed as in Example 1 to obtain an adhesive composition,
adhesive composition-treated fiber base material, and fiber base
material-highly saturated nitrile rubber composite and the same
procedure was followed to evaluate them. The results are shown in
Table 1.
Example 4
[0135] Except for changing the temperature of the polymerization
reactor from 10.degree. C. to 15.degree. C. and changing the amount
of addition of t-dodecyl mercaptan when the polymerization
conversion rate became 20% from 1.5 parts to 1.2 parts, the same
procedure was followed as in Example 1 to obtain a latex (L4) of
the highly saturated nitrile rubber (A4) (solid content
concentration 30 wt %). The ratios of content of the monomer units
of the highly saturated nitrile rubber (A4) were 34.4 wt % of
acrylonitrile units, 3.2 wt % of methacrylic acid units, and 62.4
wt % of 1,3-butadiene units (including hydrogenated parts as well),
and the iodine value was 44. Further, the same procedure was
followed as in Example 1 for performing the different measurements.
The results are shown in Table 1.
[0136] Further, except for using, instead of the latex (L1) of the
highly saturated nitrile rubber (A1), the above obtained latex (L4)
of the highly saturated nitrile rubber (A4), the same procedure was
followed as in Example 1 to obtain an adhesive composition,
adhesive composition-treated fiber base material, and fiber base
material-highly saturated nitrile rubber composite and the same
procedure was followed to evaluate them. The results are shown in
Table 1.
Example 5
[0137] Except for changing the amount of the acrylonitrile from 35
parts to 42 parts and the amount of 1,3-butadiene from 61 parts to
54 parts, the same procedure was followed as in Example 1 to obtain
a latex (L5) of a highly saturated nitrile rubber (A5) (solid
content concentration 30 wt %). The ratios of content of the
monomer units of the highly saturated nitrile rubber (A5) were 40.1
wt % of acrylonitrile units, 3.2 wt % of methacrylic acid units,
and 56.7 wt % of 1,3-butadiene units (including hydrogenated parts
as well), and the iodine value was 31. Further, the same procedure
was followed as in Example 1 for performing the different
measurements. The results are shown in Table 1.
[0138] Further, except for using, instead of the latex (L1) of the
highly saturated nitrile rubber (A1), the above obtained latex (L5)
of the highly saturated nitrile rubber (A5), the same procedure was
followed as in Example 1 to obtain an adhesive composition,
adhesive composition-treated fiber base material, and fiber base
material-highly saturated nitrile rubber composite and the same
procedure was followed to evaluate them. The results are shown in
Table 1.
Comparative Example 1
[0139] To a reactor, 180 parts of ion exchange water, 25 parts of
concentration 10 wt % sodium dedecylbenzene sulfonate aqueous
solution, 35 parts of acrylonitrile, 4 parts of methacrylic acid,
and 0.5 part of t-dodecyl mercaptan (molecular weight modifier)
were charged in that order. The inside gas was replaced with
nitrogen 3 times, then the inside was charged with 61 parts of
1,3-butadiene. The reactor was held at 10.degree. C., 0.1 part of
cumen hydroperoxide (polymerization initiator) was charged, the
polymerization reaction was made to start, and the mixture was
stirred while continuing the polymerization reaction. When the
polymerization conversion rate reached 90%, 0.1 part of
concentration 10 wt % hydroquinone aqueous solution (polymerization
terminator) was added to stop the polymerization reaction. Next, at
a water temperature of 60.degree. C., the residual monomer was
removed to obtain a latex of nitrile rubber (X6) (solid content
concentration about 30 wt %).
[0140] Further, in an autoclave, the latex of nitrile rubber (X6)
and a palladium catalyst (solution of 1 wt % palladium acetate
acetone solution and equal weight of ion exchange water mixed
together) were added so that the palladium content with respect to
the dry weight of the rubber contained in the obtained latex of the
nitrile rubber (X6) became 1,000 weight ppm. The mixture was
hydrogenated by reaction at a hydrogen pressure of 3 MPa and
temperature of 50.degree. C. for 6 hours and adjusted in solid
content concentration to obtain a latex (L6) of the highly
saturated nitrile rubber (A6) (solid content concentration 30 wt
%). The ratios of content of the monomer units of the highly
saturated nitrile rubber (A6) were 34.1 wt % of acrylonitrile
units, 3.4 wt % of methacrylic acid units, and 62.5 wt % of 1,
3-butadiene units (including hydrogenated parts as well), and the
iodine value was 31. Further, the same procedure was followed as in
Example 1 for performing the different measurements. The results
are shown in Table 1.
[0141] Further, except for using, instead of the latex (L1) of the
highly saturated nitrile rubber (A1), the above obtained latex (L6)
of the highly saturated nitrile rubber (A6), the same procedure was
followed as in Example 1 to obtain an adhesive composition,
adhesive composition-treated fiber base material, and fiber base
material-highly saturated nitrile rubber composite and the same
procedure was followed to evaluate them. The results are shown in
Table 1.
Comparative Example 2
[0142] Except for changing the amount of t-dodecyl mercaptan at the
start of polymerization from 0.5 part to 0.8 part, the same
procedure was followed as in Comparative Example 1 to obtain a
latex (L7) of a highly saturated nitrile rubber (A7) (solid content
concentration 30 wt %). The ratios of content of the monomer units
of the highly saturated nitrile rubber (A7) were 34.0 wt % of
acrylonitrile units, 3.3 wt % of methacrylic acid units, 62.7 wt %
of 1,3-butadiene units (including hydrogenated parts), and the
iodine value was 38. Further, the same procedure was followed as in
Example 1 for performing the different measurements. The results
are shown in Table 1.
[0143] Further, except for using, instead of the latex (L1) of the
highly saturated nitrile rubber (A1), the above obtained latex (L7)
of the highly saturated nitrile rubber (A7), the same procedure was
followed as in Example 1 to obtain an adhesive composition,
adhesive composition-treated fiber base material, and fiber base
material-highly saturated nitrile rubber composite and the same
procedure was followed to evaluate them. The results are shown in
Table 1.
Comparative Example 3
[0144] Except for changing the amount of the t-dodecyl mercaptan at
the time of start of polymerization from 0.5 part to 1.5 parts, the
same procedure was followed as in Comparative Example 1 to obtain a
latex (L8) of a highly saturated nitrile rubber (A8) (solid content
concentration 30 wt %). The ratios of content of the monomer units
of the highly saturated nitrile rubber (A8) were 33.7 wt % of
acrylonitrile units, 3.5 wt % of methacrylic acid units, and 62.8
wt % of 1,3-butadiene units (including hydrogenated parts as well),
and the iodine value was 47. Further, the same procedure was
followed as in Example 1 for performing the different measurements.
The results are shown in Table 1.
[0145] Further, except for using, instead of the latex (L1) of the
highly saturated nitrile rubber (A1), the obtained latex (L8) of
the highly saturated nitrile rubber (A8), the same procedure was
followed as in Example 1 to obtain an adhesive composition,
adhesive composition-treated fiber base material, and fiber base
material-highly saturated nitrile rubber composite and the same
procedure was followed to evaluate them. The results are shown in
Table 1.
[0146] Table 1
TABLE-US-00001 TABLE 1 Example Comparative Example 1 2 3 4 5 1 2 3
Type of latex L1 L2 L3 L4 L5 L6 L7 L8 Production conditions of
latex Polymerization temperature (.degree. C.) 10 15 10 15 10 10 10
10 Amount of addition of molecular (parts) 0 0 0 0 0 0.5 0.8 1.5
weight adjuster at time of start of polymerization Amount of
addition of molecular (parts) 1.5 1.2 0 1.2 1.5 0 0 0 weight
adjuster at time of polymerization conversion rate of 20% Amount of
addition of molecular (parts) 0 0 1.5 0 0 0 0 0 weight adjuster at
time of polymerization conversion rate of 40% Composition of the
highly saturated nitrile rubber Acrylonitrile units (wt %) 34.2
33.5 33.8 34.4 40.1 34.1 34 33.7 1,3-butadiene units (including (wt
%) 62.5 63 62.7 62.4 56.7 62.5 62.7 62.8 hydrogenated parts)
Methacrylic acid units (wt %) 3.3 3.5 3.5 3.2 3.2 3.4 3.3 3.5
Iodine value of the highly saturated 26 37 45 44 31 31 38 47
nitrile rubber Weight average molecular weight 52,500 66,000 34,900
51,500 49,200 179.500 131.100 74.000 of chloroform solubles
Physical properties of film product Loss tangent tan .delta. at
50.degree. C. 0.427 0.398 0.447 0.404 0.44 0.22 0.266 1.07 Loss
tangent tan .delta. at 100.degree. C. 0.672 0.641 0.71 0.659 0.652
0.434 0.554 0.43 Loss tangent tan .delta. at 150.degree. C. 0.694
0.663 0.733 0.684 0.698 0.531 0.813 1.72 .DELTA. tan .delta. = tan
.delta. - tan .delta. 0.267 0.265 0.280 0.28 0.258 0.311 0.547 0.05
Storage modulus O' at 50.degree. C. (kPa) 306.9 316.8 308.8 301.8
340.3 548.3 505.2 130.1 Storage modulus G' at 100.degree. C. (kPa)
98.9 110.8 100.5 97.7 115.5 91.4 209.1 61.2 Storage modulus G' at
150.degree. C. (kPa) 40.81 45.9 38.8 40.32 41.2 184.4 7.1 41.7
.DELTA. G' = G' - O (kPa) 206.09 270.9 270 201.48 299.1 303.9 428.1
88.4 Complex torque S at time of (dNm) 16.2 17.8 14.3 15.3 14.8
28.6 24.9 2.7 100% shear strain at 100.degree. C. Results of
evaluation Load at time of 50% stretching of (kg-weight) 1.71 1.78
1.88 2.05 1.93 3.3 2.81 0.07 adhesive composition-treated fiber
base material Abrasian resistance of fiber base 5 5 5 5 5 5 3 1
material-highly saturated nitrile rubber composite indicates data
missing or illegible when filed
[0147] Table 2
TABLE-US-00002 TABLE 2 Zetpol2020L (*1) (parts) 70 Zeoforte
ZSC2295L (*2) (parts) 30 SRF carbon black (*3) (parts) 20 Zinc
white (*4) (parts) 10 Trimellitic acid ester (*5) (parts) 5
4,4'-bis(.alpha.,.alpha.'-dimethylbenzyl)diphenylamine (*6) (parts)
1.5 Nocrac MBZ (*7) (parts) 1.5 Peroxymon F-40 (*8) (parts) 6 (*1)
Saturated nitrile rubber iodine value 28, 36.2 wt % of
acrylonitrile monomer units made by Zeon Corporation) (*2) High
saturated nitrile rubber composition containing zinc methacrylate
(made by Zeon Corporation) (*3) Product name "Seast S" (made by
Tokai Carbon) (*4) Zinc White No. 1 (ZnO#), made by Seido Chemical
Industry (*5) Product name "ADK Cizar C-8", made by ADEKA (*6)
Product mane "Nocrac CD", made by Ouchi Shinko Chemical Industial
(*7) Product name "Nocrac MBZ", made by Ouchi Shinko Chemical
Industrial (*8) Product name "Peroxymon F-40", organic peroxide
cross-linking agent (made by NOF Corporation) indicates data
missing or illegible when filed
[0148] From Table 1, when using an adhesive composition of the
present invention containing a predetermined latex of the highly
saturated nitrile rubber of the present invention, the obtained
fiber base material was excellent in stretchability. Further, the
obtained fiber base fabric-highly saturated nitrile rubber
composite was excellent in abrasion resistance (Examples 1 to
5).
[0149] As opposed to this, when using a latex of the highly
saturated nitrile rubber comprised of one where the weight average
molecular weight of the solubles in chloroform is over 100,000, the
loss tangent tan .delta..sub.(50.degree. C.) at 50.degree. C. when
made into a film is less than 0.3, and the complex torque S* at the
time of 100% shear strain at 100.degree. C. is over 20 dNm, the
obtained fiber base material was large in load at the time of 50%
stretching and was inferior in stretchability (Comparative Examples
1 and 2).
[0150] Further, when using a latex of the highly saturated nitrile
rubber comprised of one where the loss tangent tan
.delta..sub.(50.degree. C.) at 50.degree. C. when made into a film
is over 0.6, the obtained fiber base fabric-highly saturated
nitrile rubber composite was extremely inferior in abrasion
resistance (Comparative Example 3).
* * * * *