Title of Invention

RUBBER COMPOSITION AND TIRE COMPRISING THEREOF

Abstract There is provided a rubber composition in which strength and weather resistance are improved and the use of petroleum resource is suppressed as much as possible, and a tire comprising thereof. A rubber composition comprising 3 to 12 parts by weight of a pigment derived from resources other than petroleum, 10 parts by weight or less of carbon black and 30 parts by weight or more of silica based on 100 parts by weight of rubber components comprising an epoxidized natural rubber and/or a natural rubber.
Full Text RUBBER COMPOSITION AND TIRE COMPRISING THEREOF
BACKGROUND OF THE INVENTION
The present invention relates to a rubber composition and
a tire comprising thereof.
environmental problems have become serious, and the
regulation of suppressing discharge of CO2 is strengthened. And also,
supply amount is decreased year by year due to finite of petroleum raw
materials. Therefore, the inflation of petroleum price is expected in
future and there is limitation for use of the compound of a rubber
composition comprising petroleum resources such as a
styrene-butadiene rubber, carbon black and the like. Accordingly,
anticipating the depletion of petroleum in future, it is necessary to use
resources other than petroleum such as a natural rubber and fillers
such as silica and calcium carbonate for the rubber composition.
However, rubber components obtained from resources
other than petroleum such as a natural rubber have a problem that
they are easily deteriorated by external factors such as environment
using a rubber composition. In particular, in case of a rubber
composition for a tire used under irradiation of sun light, cracks are
easily generated in the rubber composition by absorbing ultraviolet
rays by rubber components; therefore there is a problem in the
weather resistance of the rubber composition. Accordingly, ultraviolet
rays have been recently shielded or absorbed by compounding an
antioxidant or carbon black, but both of the antioxidant and carbon
black are a component derived from petroleum resources.
It has been known that a large amount of iron oxides are
compounded in the rubber composition for a tire in order to improve
the weather resistance of the rubber composition (see
JP-A-2001-81241), but there has been a problem that the strength of
tne ruDDer composition is Lowered.
SUMMARY OF THE INVENTION
It is the object of the present invention to provide a rubber
composition in which strength and weather resistance are improved
and the use of components derived from petroleum resources is
inhibited as much as possible, and a tire comprising thereof.
The present invention relates to a rubber composition
comprising 3 to 12 parts by weight of a pigment derived from a
resource other than petroleum, 10 parts by weight or less of carbon
black, and 30 parts by weight or more of silica based on 100 parts by
weight of rubber components comprising an epoxidized natural rubber
and/or a natural rubber.
Further, the present invention relates to a tire comprising
the fore-mentioned rubber composition.
DETAILED DESCRIPTION
The rubber composition of the present invention comprises
a rubber component, a pigment derived from resources other than
petroleum, carbon black and silica.
The rubber component comprises an epoxidized natural
rubber (ENR) and/or a natural rubber (NR).
ENR is prepared by adding an epoxidation agent such as
peracetic acid in the emulsion of a natural rubber to be reacted. ENR
used in the present invention is not specifically limited, but specifically
includes ENR in which an epoxidation ratio is 25 % (ENR25) and 50 %
(ENR50), and the like. Additionally, ENR having a different
epoxidation ratio can be also used. These ENR may be used alone or
in a combination of two or more.
As NR, KR7, TSR and the like which are general in the tire
industry can be used.
As the rubber component, rubber components such as a
styrene-butadiene rubber (SBR) and a butadiene rubber (BR) which are
used in the tire industry can be used in a combination with ENR or NR,
but the rubber component preferably consists of ENR and/or NR
because they are resources other than petroleum and tender to
environment and effect for improving strength and weather resistance
is further obtained.
When the rubber compo.sition of the present invention is
used for the tread of a tire, the content ratio of ENR is 30 to 100 % by
weight and when it is used for the side wall, the content ratio of ENR is
preferably 50 % by weight or less.
Further, when the rubber composition of the present
invention is used for the tread of a tire, the content ratio of NR is
preferably 70 % by weight or less and when it is used for the side wall,
the content ratio of NR is preferably 50 % by weight or more. Further,
when it is used for the clinch, the content ratio of NR is preferably
100 % by weight.
The pigment derived from resources other than petroleum
means a colored inorganic filler and an organic pigment which are
obtained from natural resources other than petroleum. These may be
used alone or two or more may be used in a combination thereof.
The inorganic pigment in the present invention derived
from resources other than petroleum does not include, for example,
carbon black obtained by thermally decomposing petroleum, a white
inorganic filler such as silica, and a transparent inorganic filler.
Examples of the inorganic pigment derived from resources
other than petroleum include pigments having colors such as red,
orange, yellow, green, blue, indigo blue, purple, black and brown.
The inorganic pigment derived from resources other than
petroleum is preferably a colored metal oxide. The colored metal oxide
means metal oxides having colors such as red, orange, yellow, green,
blue, indigo blue, purple, black and brown. Specifically, ferric oxide
(III), titanium oxide, aluminum oxide, zinc oxide, barium sulfate and
the like are mentioned. Among these, colcothar (iron oxide (III)) and
barium sulfate are preferable as the colored metal oxide, because they
prevent the deterioration of a rubber by absorbing ultraviolet rays to
improve light fastness.
The average particle diameter of the colored metal oxide is
preferably 1 µm or less. When the average particle diameter of the
colored metal oxide exceeds 1 µm, rubber strength tends to be lowered.
Further, the organic pigment derived from resources other
than petroleum in the present invention includes a lake pigment which
is obtained by solidifying dyes derived from charcoal and plants.
Among these, charcoal is preferable as the organic pigment because
effect for improving strength and weather resistance is obtained.
Charcoal means those prepared by burning resources
other than petroleum such as timbers and bamboos. Specifically, the
charcoal includes bincho charcoal, bamboo charcoal and the like.
The average particle diameter of the charcoal is preferably
100 µm or less and more preferably 10 p.m or less. When the average
particle diameter of the charcoal exceeds 100 µm, properties of a
rubber such as tensile strength, tear strength and abrasion resistance
tend to be lowered.
The content of the pigment derived from resources other
than petroleum is 3 parts by weight or more based on 100 parts by
weight of the rubber components, preferably 4 parts by weight or more
and more preferably 5 parts by weight or more. When the content is
less than 3 parts by weight, ultraviolet rays are not adequately
absorbed by the pigment and crack is generated in the rubber
composition. Further, the content of the pigment derived from
resources other than petroleum is 12 parts by weight or less,
preferably 11 parts by weight or less, and more preferably 10 parts by
weight or less. When the content exceeds 12 parts by weight, the
strength of the rubber composition is lowered.
As carbon black, carbon black such as N220, N234, N350
and N550 which have the specification generally used in the tire
industry can be used. Among these, N220 carbon black is preferably
used because adequate reinforcement effect for a rubber is obtained.
The content of carbon black is 10 parts by weight or less
based on 100 parts by weight of the rubber components and preferably
5 parts by weight or less. When the content exceeds 10 parts by
weight, it is not preferable because the ratio of components other than
petroleum becomes too high in the rubber composition.
The content of silica is 30 parts by weight or more based
on 100 parts by weight of the rubber components and preferably 40
parts by weight or more. When the content is less than 30 parts by
weight, reinforcement effect for the rubber is little and rubber strength
becomes insufficient. Further, the content of silica is preferably 90
parts by weight or less and more preferably 80 parts by weight or less.
When the content exceeds 90 parts by weight, viscosity of the rubber at
kneading becomes extremely high and processability at kneading,
extrusion and the like tends to be deteriorated.
In the rubber composition of the present invention, a
silane coupling agent can be used in a combination with silica. The
silane coupling agent is not specifically limited, but specific examples
include sulfides series such as bis(3-triethoxysilylpropyl)tetrasulfide,
bis(2-triethoxysilylethyl)tetrasulfide,
bis(3-trimethoxysilylpropyl)tetrasulfide,
bis(2-trimethoxysilylethyl)tetrasulfide,
bis(3-triethoxysilylpropyl)trisulfide, bis(3-triethoxysilylpropyl)disulfide,
bis(3-trimethoxysilylpropyl)disulfide,
3-trimethoxysilylpropyl-N,N-dimethylthiocarbamoyltetrasulfide,
3-triethoxysilylpropyl-N,N-dimethylthiocarbamoyltetrasulfide,
2-triethoxysilylethyl-N,N-dimethylthiocarbamoyltetrasulfide,
3-trirnethoxysilylpropylbenzothiazolyltetrasulfide,
3-triethoxysilylpropylbenzothiazolyltetrasulfide, 3-triethoxysilylpropyl
methacrylate monosulfide and 3-trimethoxysilylpropyl methacrylate
monosulfide; mercapto series such as
3-mercaptopropyltrimethoxysilane, 3 -mercaptopropyltriethoxy silane,
2-mercaptoethyltrimethoxysilane and 2-mercaptoethyltriethoxysilane;
vinyl series such as vinyl triethoxysilane and vinyl trimethoxysilane;
amino series such as 3-aminopropyltriethoxysilane,
3-aminopropyltrimethoxysilane,
3- (2-aminoethyl)aminopropyltxiethoxysilane and
3-(2-aminoethyl)aminopropyltrimethoxysilane; glycidoxy series such as
y-glycidoxypropyltriethoxysilane, Y-glycidoxypropyltrimethoxysilane,
y-glycidoxypropylmethyldiethoxysilane and
Y-glycidoxypropylmetliyldimethoxysilane; nitro series such as
3-nitropropyltrimethoxysilane and 3-nitropropyltriethoxysilane; chloro
series such as 3-chloropropyltrimethoxysilane,
3-chloropropyltriethoxysilane, 2-chloroethyltrimethoxysilane and
2-chloroethyltriethoxysilane, and the like. These silane coupling agent
can be used solely or in a combination use thereof. Further, the
silane coupling agent can be used in a usual amount.
The rubber composition of the present invention can
contain oil as a softener. As the oil, a process oil, a plant oil and fat,
and a mixture thereof may be used.
The process oil includes specifically, paraffin process oil,
naphthene process oil, aromatic process oil and the like.
Further, the plant oil and fat includes specifically ricinus
oil, cotton seed oil, linseed oil, rape seed oil, soy bean oil, palm oil,
coconut oil, peanut oil, rosin, pine oil, pine tar, tall oil, corn oil, rice oil,
saffron oil, sesame oil, olive oil, sun flower oil, palm kernel oil, camellia
oil, jojoba oil, macadamia nut oil, safflower oil, wood oil and the like.
In the rubber composition of the present invention, various
additives such as wax, an antioxidant, stearic acid, zinc oxide, sulfur,
and a vulcanization accelerator which are usually used in the tire
industry can be suitably compounded, if necessary, in addition to the
rubber component, a pigment derived from resources other than
petroleum, silica and carbon black, and a silane coupling agent and a
softener which are compounded if necessary.
The tire of the present invention comprises the rubber
composition of the present invention and in particular, is preferably a
tire having a tread, side wall or clinch comprising the rubber
composition. In particular, the tire is preferably a tire having a tread,
side wall and clinch comprising the rubber composition.
The tire of the present invention is prepared by a usual
method using the rubber composition of the present invention.
Namely, the rubber composition of the present invention in which the
fore-mentioned rubber components, a pigment derived from resources
other than petroleum, silica and carbon black, and a silane coupling
agent, a softener and the fore-mentioned various additives which are
compounded if necessary is extruded and molded in match with the
shape of a tire member at an uncured stage and molded by a usual
method on a tire molding machine to form uncured tires. Tires can be
prepared by pressuring the uncured tires in a vulcanization machine
by heating.
EXAMPLES
The present invention is specifically illustrated based on
Examples, but the present invention is not limited thereto.
Various chemicals used in Examples are described below.
NR: TSR
ENR25: Epoxidized natural rubber (an epoxidation ratio of 25 % by
mol) manufactured by Kumpulan Guthrie Berhad Co. (Malaysia).
Carbon black: SHOWBLACK N220, manufactured by SHOWA CABOT K.
K.
Silica: ULTRASIL VN3 manufactured by Degussa Corporation (BET
specific surface area: 210 m2/g).
Colcothar: Cloisonne Mark (red) manufactured by Morishita Bengara
Co.
Natural charcoal: Bincho charcoal (purchased from ICHIAN of bincho
charcoal; black; a particle diameter of 100 µm or less).
Pigment 1: Pigment manufactured by Toda Kogyo Corporation (iron
oxide; red; a particle diameter of more than 0.5 µm and less than 5
µm).
Pigment 2: Pigment manufactured by Toda Kogyo Corporation (iron
oxide; red brown; a particle diameter of 0.5 µm or less).
Silane coupling agent: Si75 manufactured by Degussa Japan
Corporation.
Oil: Soy bean oil manufactured by Nissin Oillio Group Co.
Wax: SUNNOC WAX, manufactured by OUCHISHINKO CHEMICAL
INDUSTRIAL CO., LTD.
Antioxidant: NOCRAC 6C
(N-(l,3-dimethylbutyl)-N'-phenyl-phenylenediamine) manufactured by
OUCHISHINKO CHEMICAL INDUSTRIAL CO., LTD.
Stearic acid: STEARIC ACID manufactured by NOF Corporation.
Zinc oxide: ZINC OXIDE No.l manufactured by Mitsui Mining And
Smelting Company, Limited.
Sulfur: SULFUR POWDER manufactured by Tsurumi Chemical
Industry Co., Ltd.
Vulcanization accelerator NS: NOCCELER CZ manufactured by
OUCHISHINKO CHEMICAL INDUSTRIAL CO., LTD.
EXAMPLES 1 to 15 and COMPARATIVE EXAMPLES 1 to 12
After the fore-mentioned various chemicals excluding
sulfur and a vulcanization accelerator which were described in Tables
1 to 3 were kneaded with 1.7 L Banbury mixer manufactured by Kobe
Steel Ltd. at 140°C for 4 minutes, sulfur and a vulcanization
accelerator were compounded and kneaded with an open roll at 80°C
for 2 minutes to obtain uncured products.
The uncured products in Examples 1, 2, 5, 6, 9, 10 and 11
and Comparative Examples 1, 2, 5, 6, 9 and 10 were molded into a
tread shape, the uncured articles in Examples 3, 7, 12 and 13 and
Comparative Examples 3, 7 and 11 were molded into a side wall shape,
and the uncured articles in Examples 4, 8, 14 and 15 and Comparative
Examples 4, 8 and 12 were molded into a clinch shape, respectively.
Respective treads, side walls and clinches were prepared by
vulcanizing the uncured molded articles with a tread shape, a side wall
shape and a clinch shape at 150°C for 35 minutes.
Samples were cut out from the treads, the side walls and
the clinches which were obtained, and were used for tests below.
(Rubber strength)
Tensile test was carried out in accordance with JIS K6251
using the fore-mentioned rubber samples, and tensile strength at
break (hereinafter referred to as TB) and elongation at break
(hereinafter referred to as EB) of test pieces were respectively measured.
Then, rubber strength was calculated by the formula below using TB
(Rubber strength) = TB x EB/2
Further, with respect to the rubber strengths obtained, the
rubber strength of Comparative Example 1 was referred to as 100 in
Examples 1 to 2 and Comparative Examples 1 to 2, that of
Comparative Example 3 was referred to as 100 in Example 3 and
Comparative Example 3, that of Comparative Example 4 was referred
to as 100 in Example 4 and Comparative Example 4, that of
Comparative Example 5 was referred to as 100 in Examples 5 to 6 and
Comparative Examples 5 to 6, that of Comparative Example 7 was
referred to as 100 in Example 7 and Comparative Example 7, that of
Comparative Example 8 was referred to as 100 in Example 8 and
Comparative Example 8, further, that of Comparative Example 9 was
referred to as 100 in Examples 9 to 11 and Comparative Examples 9 to
10, that of Comparative Example 11 was referred to as 100 in
Examples 12 to 13 and Comparative Example 11 and that of
Comparative Example 12 was referred to as 100 in Examples 14 to 15
and Comparative Example 12, and respective rubber strengths were
represented by index.
(Weather resistance)
The rubber samples which were elongated by 120 % were
exposed outdoor for 2 months and crack was visually observed. Those
in which no crack was generated were described as "O" and those in
which crack was generated were described as "x".
The test results are shown in Tables 1 to 3.
According to the present invention, there can be provided a
rubber composition in which strength and weather resistance are
improved and the use of components derived from petroleum resources
is inhibited as much as possible, and a tire comprising thereof, by
containing a specific rubber component, carbon black and silica, and
further, a pigment derived from resources other than petroleum.
What we claim is :
1. A rubber composition comprising 3 to 12 parts by
weight of a pigment derived from resources other than petroleum, 10
parts by weight or less of carbon black and 30 parts by weight or more
of silica based on 100 parts by weight of rubber components
comprising an epoxidized natural rubber and/or a natural rubber.
2. A tire comprising the rubber composition according to
Claim 1.


There is provided a rubber composition in which strength
and weather resistance are improved and the use of petroleum
resource is suppressed as much as possible, and a tire comprising
thereof. A rubber composition comprising 3 to 12 parts by weight of a
pigment derived from resources other than petroleum, 10 parts by
weight or less of carbon black and 30 parts by weight or more of silica
based on 100 parts by weight of rubber components comprising an
epoxidized natural rubber and/or a natural rubber.

Documents:

00017-kol-2006-abstract.pdf

00017-kol-2006-claims.pdf

00017-kol-2006-description complete.pdf

00017-kol-2006-form 1.pdf

00017-kol-2006-form 2.pdf

00017-kol-2006-form 3.pdf

00017-kol-2006-form 5.pdf

17-KOL-2006-AMENDED ABSTRACT 1.1.pdf

17-KOL-2006-ANEXURE TO FORM 3.pdf

17-kol-2006-assignment.pdf

17-KOL-2006-CANCELLED PAGES.pdf

17-KOL-2006-CLAIMS 1.1.pdf

17-kol-2006-correspondence 1.1.pdf

17-kol-2006-correspondence 1.2.pdf

17-KOL-2006-CORRESPONDENCE.pdf

17-KOL-2006-DESCRIPTION (COMPLETE) 1.1.pdf

17-kol-2006-examination report.pdf

17-KOL-2006-FORM 1.1.1.pdf

17-kol-2006-form 18.pdf

17-kol-2006-form 3 1.1.pdf

17-kol-2006-form 5.pdf

17-KOL-2006-FORM-27.pdf

17-kol-2006-gpa.pdf

17-kol-2006-granted-abstract.pdf

17-kol-2006-granted-claims.pdf

17-kol-2006-granted-description (complete).pdf

17-kol-2006-granted-form 1.pdf

17-kol-2006-granted-form 2.pdf

17-kol-2006-granted-specification.pdf

17-KOL-2006-OTHERS.pdf

17-KOL-2006-PETITION UNDER RULE 137.pdf

17-kol-2006-priority document 1.1.pdf

17-KOL-2006-PRIORITY DOCUMENTS.pdf

17-kol-2006-reply to examination report 1.1.pdf

17-KOL-2006-REPLY TO EXAMINATION REPORT.pdf


Patent Number 245028
Indian Patent Application Number 17/KOL/2006
PG Journal Number 53/2010
Publication Date 31-Dec-2010
Grant Date 29-Dec-2010
Date of Filing 10-Jan-2006
Name of Patentee SUMITOMO RUBBER INDUSTRIES LTD.
Applicant Address 6-9, WAKINOHAMA-CHO 3-CHOME CHUO-KU, KOBE-SHI HYOGO-KEN
Inventors:
# Inventor's Name Inventor's Address
1 HIRAYAMA TOMOAKI C/O SUMITOMO RUBBER INDUSTRIES LTD. 6-9, WAKINOHAMA-CHO 3-CHOME CHUO-KU, KOBE-SHI HYOGO-KEN
2 UCHIDA MAMORU C/O SUMITOMO RUBBER INDUSTRIES LTD. 6-9, WAKINOHAMA-CHO 3-CHOME CHUO-KU, KOBE-SHI HYOGO-KEN
3 WADA TAKAO C/O SUMITOMO RUBBER INDUSTRIES LTD. 6-9, WAKINOHAMA-CHO 3-CHOME CHUO-KU, KOBE-SHI HYOGO-KEN
PCT International Classification Number C08L15/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 2005-036333 2005-02-14 Japan