Note: Descriptions are shown in the official language in which they were submitted.
2 ~ r~
BACKGROUND OF THE INVENTION ~ -
The present invention relates to a pneumatic
vehicle tire of rubber or rubber-like synthetic
elastomeric material, with the tire having a tread ~.
strip, a reinforcing belt, two sidewalls, a carcass
that is anchored in beads by being looped about
bead cores that are pull-resistant and/or reslstant
to compression, and respective profiled inner
elements that are disposed radially outwardly of
the bead cores.
With heretofore known pneumatic vehicle tires,
between 8 and 15 different rubber mixtures were
used for the individual components of the tire in
order to satisfy the different requirements made of
these individual components. For example, with
regard to the tread strip the primary consideration
ls a hlgh reslstance to wear or abraslon, whereas
for the sldewalls hlgh demands are set for the
flexure and the reslstance to aglng: the proflled
20 lnner elements must have a great hardness ln order ~ ~;
to stlll the tlre ln the bead reglon.
It ls an obJect of the present lnventlon to
provlde a pneumatlc vehlcle tlre where the
propertles of the lndlvldual components are
lmproved, and where the requlrements that are
imposed can be satisfied with a low number of
: ~.: . .. : . .. . .. . .
rubber mixtures.
BRIEF DESCRIPTION OF THE DRAWING
This ob~ect, and other obJects and advantages
of the present invention, will appear more clearly
::. : . .. . -
from the followlng specification in con~unction
with examples of mixtures for the individual
components and in con~unction with the accompanying
schematic drawing, which is a cross~sectioned view
of part of one exemplary embodiment of the
pneumatic vehicle tire of the present invention.
SUMMARY OF THE INVENTION
The pneumatic vehicle tire of the present
lnvention is characterized primarlly in that at
least one of the element~ of tread strip,
sidewalls, profiled inner elements, beads, and
rubber coatings for the load-carrying means is
formed of a rubber mixture comprising 30 to 100
.; .:. , :. .
parts, per 100 parts rubber, i.e. 30 to 100% by ~ ;
weight, with respect to the rubber fraction, of a
nitrile-group-containing hydrocarbon rubber having
a double bond proportion of no greater than 13/100
C atoms.
. :,, . :
The number of rubber mixtures that are
required can be greatly reduced if all of the
components tread strip, sidewalls, profiled inner ~ -
.- ~
elements, beads, and rubber coatings for the load-
- 2 -
:.~:. . .
2 ~ ~ ~ 9J '~
carrying means are formed of rubber mixtures
comprlæing 30 to 100% by weight, of a nitrile~
group-containing hydrocarbon rubber having a double
bond proportion of no greater than 13/100 C atoms.
In so doing, one can essentially get away with
merely three different rubber mixtures, which in
addition are also based on the same type of rubber.
One arrlves at three rubber mixtures if a first
mixture is selected for the tread strip and
sidewalls, a second mixture is used for the rubber
or elastomeric coatings of the bead core, of the
carcass, and of the belt, and a third mixture is
provided for the beads and profiled inner elements. -
The result i8 a tire that i8 distinguished by an ;
exceptional resistance to wear, resistance to high
temperature, and resistance to oil. As a result of
the inventlve use of HNBR or HNIR, an increased
resistance to heat up to about 150 C is achieved.
The physical properties of the inventive mixtures
remain nearly constant over an extremely wide
temperature range. Finally, the high resistance to
aging ls significant. Due to the extremely high
air lmpermeability of the inventive mixtures, the
conventionally required inner layer of butyl rubber
can be eliminated. If the inventive mixtures are
utilized in the tread strip and in the sidewall
. . ,. . ~; .. ; , . ,, . , ~
regions, these regions can be designed ~ ~;
approximately 25% thinner than is possible with
conventional tires due to the greatly improved
propertles of the inventive rubber mixtures, this
leads to a great savings in weight. Furthermore,
with the inventive tire, some of the conventional
fabric plies in the form of belt cover or cap plies
or bead reinforcing lnserts, which up till now
could not be altered, can be eliminated.
The nitrile-group-containing rubber can be
produced, for example, by hydrogenation of nitrile
butadiene rubber or nitrile isoprene rubber, or in -
some other suitable manner. The rubber mixture for
the indlvldual components of the tlre should
contain 30 to 100~ by weight, and preferably 60 to
100% by weight, of the nitrile-group-containing
rubber.
The sidewall mixture can be very absorptive
and can have a rebound elasticity of less than 40%.
Further speclfic features of the present
invention will be described in detail subsequently.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawing in detail, the - `
illustrated tire comprises a radial carcass 1 that
... . . . . .
is anchored in the beads 2 by being looped around --~
pull-resistant bead cores 3. At the sides, the
- 4 -
tread strip 4 leads into sidewalls 5. A
aonventional reinforcing belt 6 is disposed
radially outwardly of the radial carcass 1.
Disposed radially outwardly of the bead cores 3 are
profiled inner elements 7. The rubber coatings of
the carcass 1, the reinforcing belt 6, and the
cores 3 are designated by the reference numeral 8.
Several examples of mixtures for the
individual components of the tire will be described
subseguently.
EXAMPLES OF MIXTURES FOR THE TREAD SURFACE
Pursuant to one preferred specific embodiment
of the present invention, the mlxture for the tread
surface contains a partially saturated rubber
having nitrile groups and having a double bond
proportion between 2/100 and 13/100 C atoms, and
furthermore has a sulfur polymerization scheme.
This results in a rubber having an improved dynamic
loading capacity. Wear or abrasion value~ of less ~ -~
than 50 mm3, and even less than 30 mm3, are
achieved. ~ ;
-- 5 --
? ~ 7 l s
. .~
Example I (% by weight)
100 rubber HNBR
FEF black "
ester plasticizer
4 zina oxide
2 stearic acid ;~
3 magneslum oxide
antioxidant ~-
2 paraffin wax
10 1.7 sulfur ;~
2 cyclohexylbenzothiazolesulfenamlde
0.2 tetramethylthluram dlsulfide .
(thlram)
. - . ~
Physlcal propertles: ;~
. . . ~, : ~ ~:,
Strength: 22 MPa , --~
:::: : :,.
Breaklng elongation: 440 %
~. .: . ., :.: ::
Modulus 100 % : 3 MPa
: . .. ... ..
Modulus 300 % : 14 MPa
Hardness: 65 Shore A .- .
:: , . ...... ............ .
20 Wear (DIN): 30 mm3 : :
Rebound elastlclty: 33 %
Example II (% by welght)
rubber HNBR : ,~
polybutadiene (80 % cis 1,4
GPF black
zinc oxlde :
2 stearic acid ~ ,~
'''~'`' '` ~ :
- 6 ~
2 ~ 7 ~
4 antioxidant
3 magnesium oxide
8 ester plasticizer
2 sulfur
1.5 mercaptobenzothiazyl disulfide
0.5 tetramethylthiuram disulfide
(thiram)
Physical Properties
Strength: 18.5 MPa
10 Breaking elongation: 440 % :`
Modulus 100 % : 4.3 MPa
Modulus 300 % : 16.6 MPa
Hardness: 71 Shore A
Wear: 22 mm3
Rebound elasticity: 38 %
Example III (% by weight) ~ ~-
100 rubber HNBR
SRF blac~
~ " ~
zinc white
2 magnesium oxide .
2 stearlc acid ~,
ester plasticizer -
bis (tert-butylperozy isporopyl)
benzene
2 trisallyl isocyanurate
' '` - .
,~
'-
7 '~ $ ~:
Physical Properties ~;~
Strength: 26 MPa
Breaking elongation: 330 %
Modulus 100 % : 5.7 MPa
Modulus 300 % : 24.5 MPa
Hardness: 70 Shore A
Wear: 27 mm3
Rebound elasticity: 33 %
In example I, the rubber was entirely a
partially hydrogenated nitrile rubber, and a
polymerization scheme based on sulfur was used.
With thls mixture, a wear value of 30 m3 and a `~
rebound elasticity of 33% was achieved. ~ ;
In example II, a blend of 80% by weight HNBR -- -
and 20% by weight polybutadiene are used as the
rubber components, and a mixture is again
vulcanized with a sulfur polymerization scheme.
With regard to the physical propertles, in
partlcular the extremely low wear value of 22 mm3~ ~ -
20 should be noted. The rebound elasticity was 38%. -
In example III, the rubber components were
entirely HNBR, with the polymerization being
effected via a peroxide polymerization scheme. A ;
wear value of 27 mm3 and a rebound elasticity of
33% resulted.
It should be noted that with regard to the
- 8 - `
'i~
preceding three examples, HNIR could have been used
instead of HNBR for the rubber components. In
addition, it is, of course, possible to provide
rubber components whereby the nitrile-group-
containing saturated or partially saturated
hydrocarbon rubbers HNBR and HNIR are blended with
other rubbers.
EXAMPLES OF THE MIXTURE FOR THE SIDEWALL
Pursuant to one preferred specific embodiment,
10 the sidewall mixture contains a partially saturated -
rubber having nitrile groups and having a double -
bond proportion between 2/100 and 13/100 C atoms,
and furthermore has a sulfur polymerization scheme. -
In so dolng, a rubber having an lmproved dynamic ;
loadlng capabillty ls achleved. Wear or abrasion `~
values of less than 50 mm3, and even less than 30
mm3, were achleved.
Example IV (% by weight)
100 rubber HNBR : :.
SRF black
7 sulfonic acid ester plasticizer
zinc oxide
2 stearic acid
3 magnesium oxide
antioxldant
2 paraffln wax
2 ~ ~ ~, r~
2.0 sulfur
0.1 tetramethylthiuram disulflde
(thiram)
1.5 mercaptobenzothiazyl disulfide
Physical Properties
Strenth: 15 MPa ~ .
Breaking elongation: 510 %
Modulus 100 % : 1.5 MPa
Modulus 300 ~ : 5.2 MPa
10 Hardness: 55 Shore A . .-
Wear: 70 mm3 . .'.` ~
Rebound elasticity: 65 % ~ -
Example V (% by weight) . ,~
rubber HNBR
polybutadiene (80% cis 1,4-)
GPF black
zlnc oxide -
2 stearic acid
4 antioxidant :~
3 magnesium oxide
8 ester plasticizer
2 sulfur
1.5 mercaptobenzothiazyl disulfide -.-~
0.5 tetramethylthiuram disulfide ~
(thiram) ~ -
:,
.
- 10 - .'. ''
. .
-
~ ~ Cb ,~ r ~
Physical Properties
Strength: 18.5 MPa
Breaking elongation: 440 %
Modulus 100 % : 4.3 MPa
Modulus 300 % : 16.6 MPa
Hardness: 71 Shore A
Wear: 22 mm3
Rebound elasticity:38 %
In example IV, the rubber was entirely a -;-~
partially hydrogenated nitrile rubber, and a
polymerlzation scheme on the basis of sulfur was
used. ~!t;~
In example V, the rubber component was a blend
of 80~ by weight HNBR and 20% by weight
polybutadiene, and the mlxture was again vulcanized
with a sulfur polymerization scheme. Wlth regard
to the physical properties, of particular note is
the extremely low wear value of 22 mm3. The ~ ~
rebound elasticity was 38%. This results in a ~ -
highly absorptive sidewall mixture, and hence in a
tire that has an increased dampening of tire noise
and improved driving stability, an in particular
and improved steering precision.
It should be noted that for the two preceding
examples, the rubber component can also include ; --
HNIR in place of HNBR. Furthermore, it is, of
- 1 1 - - : - .,
" ' '~ ~ .~ .`.' -' ' '
.. : ~ :` '~ '
2 ~
- ~ :
course, possible for the nitrile-group-containing
saturated or partially saturated hydrocarbon .
rubbers HNBR and HNIR to be blended with further
rubbers to form the rubber component.
EXAMPLES OF THE MIXTURE FOR THE BEAD AND/OR -~
PROFILED INNER ELEMENT
Example VI (% by weight) . ~
100 rubber HNBR -~ .
GPF black
zinc oxide
1 stearic acid
2 magnesium oxide .
4 antioxidant ~ ~
2 paraffin wax ~ ::
1.7 sulfur
1.5 mercaptobenzothiazyl disulfide ~ :
0.5 tetramethylthluram disulfide ;
(thlram)
Physical Properties
20 Strength: 23.5 MPa
Breaking elongation: 470 %
Modulus 100 ~ : 3.1 MPa
Modulus 300~ : 12.3 MPa :-
Hardness: 80 Shore A ~ ~.
~" ., '
- 12 - -: : : :
.: ' ~: :
. .
Example VII (% by weight)
100 rubber HNBR -
FEF black
ester plasticizer ; ;~
2 zinc oxide
2 stearic acid
3 antioxidant
7 magnesium oxide
1 paraffin wax
106 bi~ (tert-butylperoxy isopropyl)
benzene
2 trisallyl isocyanurate : ~ -
"~ ~:
Physical Properties ~ : -
Strength: 21.2 MPa ~ :
Breaking elongation:380 %
Modulus 100 % : 4.2 MPa
Modulus 300 % :18 MPa
Hardness: 73 Shore A
Example VIII (% by weight) ;
20 80 rubber HNBR
SBR
FEF black . ;~
ester plasticlzer . . :-
2 zinc oxide .
2 stearic acid
3 antioxldant `~-
- 13 ~
.-~.,...., ~-..-.-
'',- ~-'`'`,
.,~ : .
7 magnesium oxide
., ~ . . -~ . .
1 paraffin wax ~ -
6 bis (tert-butylperoxy isopropyl)
2 trisallyl isocyanurate
In example VI, the rubber component was .
entirely a partially hydrogenated nltrile rubber, . ~-
and a po'ymerization scheme based on sulfur was
used. ~he mlxture had a hardness of 80 Shore A.
In example VII, a peroxide polymerization
scheme was used, and the mixture was ad~usted to a
hardness of 73 Shore A.
In example VIII, the rubber component was a
blend of 80% by weight HNBR to 20% by weight parts
styrene-butadiene rubber. And the mlxture was
agaln vulcanlzed using a peroxide polymerization
scheme. Essentially the same physlcal properties
resulte~ as with example VII.
It should be noted that with the preceding
three examples, HNIR could be used in the rubber ~ .
component in place of HNBR. Furthermore, it is, of
course, possible to use a blend of the nitrile-
group-containlng saturated or partially saturated . - -.
. : . ~-:.-:
hydrocarbon rubbers HNBR and HNIR with further
rubbers as the rubber component; thls is
particularly applicable where a peroxide ;~
polymerization scheme is used. -
- 14 - ``~ ~
-'` ` : :: ~ '
,'''',','.,','.,'''",'.""',;"'.'',''''','.''-',"'''
.. ~: . ~ .. - . . .. ,., . ~ . : , - .
For mixtures pursuant to the heretofore known -~
state of the art, it is generally necessary to use
phenolic resins in order to obtain the required
hardness. However, phenolic resins have the
drawback that the rubber remalns permanently
elongated when lt ls overstressed. Thls drawback
ls avolded wlth the inventlve mlxtures, whlch
contain no phenollc resins. A further advantage of
the present invention ls a very high resistance to
aging as well as improved residual compression
:
strain values. The rubber component of the mixture
for the bead and/or proflled inner element should
be 30 to 100% by weight, and preferably 60 to 100
by weight, HNBR or HNIR.
. ~
EXAMPLES OF THE RUBBER MIXTURE FOR RUBBER COATINGS
OF LOAD-CARRYING MEANS
Example IX (% by weight)
100 rubber HNBR
SRF black -~ -
20 5 zinc oxide -~
1 stearic acld
: .: ,: :; -;
1 magnesium oxide `~ ;
2 antioxidant
: . - .: , .. .
2.0 sulfur `
0.1 tetramethylthiuram dlsulflde
(thiram) - -~
1.5 mercaptobenzothiazyl disulfide
- 15 ~
: . -: . -~':
~'.' '-~'~' :
' ,.`' ' .
~ . - : . . . . . .
$ ~ ::
.
...
.. ... ~ ~ -
Physical Propertles
Strenth: 18 MPa :
Breaking elongation:450 %
Modulus 100 % : 2.6 MPa
Modulus 300 % : 12.4 MPa
Hardness: 64 Shore A ~ :
Permeabillty to air:10-17 m2/Pa.s .
Example X (% by weight)
rubber HNBR
10 20 NR :
; ~: :. . ~ . .:
SRF black ~:
zinc oxide
I stearic acid
1 magnesium oxide
2 antioxidant .~
2.0 sulfur -
0.1 tetramethylthiuram disulfide .. :.:~
(thiram)
1.5 mercaptobenzothiazyl disulfide
In example IX, the rubber component was .
entirely a partially hydrogenated:nitrile rubber,
-::: , ~
and a polymerization scheme based on sulfur was ~:~
used. Wlth this mlxture, a permeability to air of
about 10-17 m2/Pa~s was achieved.
In example X, the rubber component was a blend ~ :
of 80% by weight HNBR and 20% by weight natural
- 16 - ~ :
~' ~.: :
. .
...... -. . : . : . . . . .
. .. , :. ~ . . . . ....
. :,.: :.:: .,.., -,. .. , . :. ~ . i
~ 2~7~
rubber, and the mixture was again vulcanized ~ -
utilizing a sulfur polymeri7atlon scheme.
Essentially the same physical properties were ~ -
achieved as with example IX. ~;
It should be noted that with the preceding two
examples, HNIR can be used in the rubber component
ln place of HNBR. Furthermore, it ls, of course,
posslble to use a blend of the nltrlle-group~
contalnlng saturated or partlally saturated
10 hydrocarbon rubbers HNBR an HNIR with further ; -
rubbers as the rubber component.
As a consequence of the inventive use of HNBR `
or HNIR, a universal mixture is obtained for rubber ~ ;
coatings for the embedment of load-carrying inserts - ~
for components that are used to construct a tire. - -
In contrast to heretofore known rubber coatlngs, -
wlth the present inventlon a decldedly lmproved
dynamic loading capacity and an improved reslstance
to aging are obtalned. Furthermore, an lncreased
thermal resistance to about 150 C ls achleved.
The physlcal propertles of the lnventlve mlxtures
: ., :
remaln nearly constant over an extremely wlde
temperature range. Due to the extremely hlgh
lmpermeabllity to alr, when the lnventive mlxture
is used as the rubber coatlng for the carcass, the
heretofore conventional butyl rubber inner layer ~ ~;
- 17 - ~
. ~ -
.. . . . ..
can be eliminated.
Pursuant to one preferred specific embodiment
of the present invention, the rubber mixture of the ;
rubber coating contains a partially saturated
rubber having nitrile groups and having a double
bond proportion between 2/100 and 13/100 C atoms,
and furthermore has a sulfur polymerization scheme.
In so doing, a rubber having a still further
improved dynamic loading capacity is obtained. Air
permeability values (~T) of approximately 10-17
m2/Pa~ 8 are obtained.
The nitrile-group-containing rubber can, for `;; -
example, be produced by hydrogenating nitrile-
butadiene rubber or nitrile-isoprene rubber, or in
some other manner. The mixture for the rubber
coating should contain 30 to 100% by weight, and --
preferably 60 to 100% by weight, of this rubber
relative to the total amount of rubber.
The present invention is, of course, in no way
restricted to the specific disclosure of the
specification, examples, and drawing, but also
encompasses any modifications within the scope of
the appended claims.
- 18 -
.. . ~ :: :, . . . : :
