FORM 2
THE PATENTS ACT, 1970 (39 of 1970) & THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10, rule 13)
1. Title of the invention: VULCANIZABLE RUBBER COMPOSITION COMPRISING
EPOXY RESIN
2. Applicant(s)

NAME NATIONALITY ADDRESS
CEAT LIMITED Indian RPG HOUSE, 463, Dr. Annie Besant Road, Worli, Mumbai, Maharashtra-400 030, India
3. Preamble to the description
COMPLETE SPECIFICATION
The following specification particularly describes the invention and the manner in which it
is to be performed.

TECHNICAL FIELD
[0001] The subject matter described herein in general relates to a rubber composition, and particularly discloses a vulcanizable rubber composition comprising diene elastomer, crosslinking agent, and epoxy resin.
BACKGROUND OF INVENTION
[0002] The physical properties of a tire depend very much on the chemical composition of the vulcanizable rubber composition which is used for preparing the tire. An ideal tire should be able to maintain its grip on the road and should be resilient to abrasion, caused due to the friction between the road and tire. [0003] The performance of the tire is affected by rolling resistance, tire wear, tire temperature, tire noise, and cornering properties (Virkar, D. S., and D. G. Thombare; 2013; www.academia.edu). During the movement of a tire, the mechanical energy gets converted to heat energy because of the rolling resistance of the tire. Rolling resistance of a tire has a profound impact on the fuel consumption of a vehicle. Rolling resistance is a property that is a manifestation of viscoelastic behavior of elastomers present in the tread composition (Thomas, F. et al. 2009; Tire Science and Technology 37; 4:254-278). The properties of tire temperature and tire wear correlates with the longevity of a tire, whereas tire noise has to be dealt with from an angle of a continuous quest to reduce the noise pollution caused because of movement of tire on roads. The cornering properties are important to control the direction of a vehicle. Upon interaction of the tire and road, ideal traction for acceleration and braking should be achieved for preventing the possibility of slipping. Hence, an ideal tire should exhibit lower rolling resistance along with excellent traction and abrasion resistance.
[0004] In order for a tire to overcome high abrasion which it faces during its lifetime, the tread compounds used for preparing the tire should have a high hardness to provide the required penetration and high wear resistance to resist wear and tear. The tread compounds should also have low modulus sufficient enough to prevent tearing off. Tan delta value in the desired range further helps in lowering the rolling

resistance of the tire. Therefore, an ideal tire should strike a balance between the
above-mentioned properties which can be achieved by making changes to the
vulcanizable rubber composition.
[0005] US5208276A discloses a tire tread compound, particularly useful for truck
tires, comprises a base polymer of natural or synthetic rubber, a filler at least 50% of
which is carbon black and between 2 and 10 parts of epoxy resin per hundred parts
of polymer.
[0006] FR2951182A1 discloses a rubber composition usable particularly in tires,
based on at least one diene elastomer, a reinforcing filler, a crosslinking system, an
epoxy resin and an amine hardener.
[0007] The prior art either uses a higher content of reinforcing filler in the form of
carbon black in tread compound (US5208276A) or uses a hardener system
(FR2951182A1) for obtaining a rigid tire rubber composition. The properties of tire
significantly change with respect to the change in composition in different parts of
the tire. Therefore, a rubber composition providing a solution to the rigidity issues
and also simultaneously providing better mechanical properties is the need of the
hour.
SUMMARY OF THE INVENTION
[0008] In a first aspect of the present disclosure, there is provided a vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy resin has a softening temperature in the range of 75 °C- 140°C. [0009] In a second aspect of the present disclosure, there is provided a vulcanized elastomer obtained from the composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy resin has a softening temperature in the range of 75 °C- 140°C. [0010] In a third aspect of the present disclosure, there is provided a process for preparing the vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy resin has a softening temperature in the range of 75 °C- 140°C, said process comprising: (i) obtaining at least one epoxy resin; (ii) obtaining at least

one diene elastomer; (iii) obtaining at least one crosslinking agent; and (iv) contacting the at least one epoxy resin, the at least one diene elastomer, and the at least one crosslinking agent, to obtain the composition.
[0011] These and other features, aspects, and advantages of the present subject matter will be better understood with reference to the following description and appended claims. This summary is provided to introduce a selection of concepts in a simplified form. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
DETAILED DESCRIPTION OF THE INVENTION
[0012] Those skilled in the art will be aware that the present disclosure is subject to
variations and modifications other than those specifically described. It is to be
understood that the present disclosure includes all such variations and modifications.
The disclosure also includes all such steps, features, compositions, and compounds
referred to or indicated in this specification, individually or collectively, and any and
all combinations of any or more of such steps or features.
Definitions
[0013] For convenience, before further description of the present disclosure, certain
terms employed in the specification, and examples are delineated here. These
definitions should be read in the light of the remainder of the disclosure and
understood as by a person of skill in the art. The terms used herein have the meanings
recognized and known to those of skill in the art, however, for convenience and
completeness, particular terms and their meanings are set forth below.
[0014] The articles “a”, “an” and “the” are used to refer to one or to more than one
(i.e., to at least one) of the grammatical object of the article.
[0015] The terms “comprise” and “comprising” are used in the inclusive, open sense,
meaning that additional elements may be included. It is not intended to be construed
as “consists of only”.
[0016] Throughout this specification, unless the context requires otherwise the word
“comprise”, and variations such as “comprises” and “comprising”, will be

understood to imply the inclusion of a stated element or step or group of element or
steps but not the exclusion of any other element or step or group of element or steps.
[0017] The term “including” is used to mean “including but not limited to”.
“Including” and “including but not limited to” are used interchangeably.
[0018] Ratios, concentrations, amounts, and other numerical data may be presented
herein in a range format. It is to be understood that such range format is used merely
for convenience and brevity and should be interpreted flexibly to include not only
the numerical values explicitly recited as the limits of the range, but also to include
all the individual numerical values or sub-ranges encompassed within that range as
if each numerical value and sub-range is explicitly recited. For example, a softening
temperature range of about 75–140°C should be interpreted to include not only the
explicitly recited limits of about 75°C to about 140°C, but also to include sub-ranges,
such as 80–100°C, 105–140°C, and so forth, as well as individual amounts, including
fractional amounts, within the specified ranges, such as 110 °C, and 125 °C, for
example.
[0019] The term “at least one” is used to mean one or more and thus includes
individual components as well as mixtures/combinations.
[0020] For the purposes of the present disclosure, the term “phr” refers to parts per
hundred rubber, it is a unit well used in the field of rubber technology to define the
amount of ingredients used.
[0021] The term “softening temperature” is a well-known term in the art. It refers to
the temperature at which a material softens. It can be determined by the Vicat
method, Heat Deflection Test or a ring and ball method.
[0022] Unless defined otherwise, all technical and scientific terms used herein have
the same meaning as commonly understood by one of ordinary skill in the art to
which this disclosure belongs. Although any methods and materials similar or
equivalent to those described herein can be used in the practice or testing of the
disclosure, the preferred methods, and materials are now described. All publications
mentioned herein are incorporated herein by reference.
[0023] The present disclosure is not to be limited in scope by the specific
embodiments described herein, which are intended for the purposes of

exemplification only. Functionally-equivalent products, compositions, and methods are clearly within the scope of the disclosure, as described herein. [0024] One of the objective of the present disclosure is to provide a vulcanizable elastomer composition having improved hardness and better physical properties. The composition so formed should maintain a balance between the property of high hardness and low modulus that is essential in preventing the tearing off, of the tread. Epoxy can improve hardness, tensile strength and elongation at break without increasing modulus thereby reducing the wear, cut and chip. It can also reduce energy loss thereby reducing rolling resistance (RR). Bead filler requires high hardness and good adhesion between bead wire and rubber. Hardness can generally be increased by adding more carbon black or higher structure carbon black, but it will lead to higher heat build-up thereby leading to more energy loss and deteriorating other properties of the tire.
[0025] As discussed previously, the prior art makes use of a higher percentage of carbon black without discussing the other concerned issues which can act as pitfalls. The presence of higher percentages of the inorganic fillers leads to heat buildup and energy loss, which further leads to an increase in rolling resistance and decrease in many properties, such as tensile, elongation, wear, tear, aging, flex etc. The present disclosure uses organic reinforcing fillers, such as epoxy to reduce heat buildup and energy loss that can occur while using inorganic fillers alone. Further, the present disclosure also discloses a specific range of softening temperatures of epoxy resin that needs to be used for obtaining desirable qualities of the vulcanizable elastomer composition. Particularly, the present disclosure discloses a vulcanizable elastomer composition to be used as part of a bead apex compound.
[0026] In order to provide a vulcanizable elastomer composition with improved hardness, the present disclosure discloses a vulcanizable elastomer composition comprising at least one epoxy resin; at least one diene elastomer; and at least one crosslinking agent, wherein the at least one epoxy resin has a softening temperature in the range of 75°C-140°C. The composition of the present disclosure improves the hardness without affecting other properties of the rubber.

[0027] In an embodiment of the present disclosure, there is provided a vulcanizable
elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene
elastomer; and (c) at least one crosslinking agent.
[0028] In an embodiment of the present disclosure, there is provided a vulcanizable
elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene
elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy
resin has a softening temperature in the range of 75 °C- 140°C. In another
embodiment of the present disclosure, the at least one epoxy resin has a softening
temperature in the range of 103 °C- 130°C. In yet another embodiment of the present
disclosure, the at least one epoxy resin has a softening temperature in the range of
105°C- 127°C.
[0029] In an embodiment of the present disclosure, there is provided a vulcanizable
elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene
elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy
resin has a softening temperature in the range of 105°C- 140°C.
[0030] In an embodiment of the present disclosure, there is provided a vulcanizable
elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene
elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy
resin has a softening temperature in the range of 105°C- 130°C.
[0031] In an embodiment of the present disclosure, there is provided a vulcanizable
elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene
elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy
resin has a softening temperature of 75°C.
[0032] In an embodiment of the present disclosure, there is provided a vulcanizable
elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene
elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy
resin has a softening temperature of 110°C.
[0033] In an embodiment of the present disclosure, there is provided a vulcanizable
elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene
elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy
resin has a softening temperature of 140°C.

[0034] In an embodiment of the present disclosure, there is provided a vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy resin has a softening temperature in the range of 75 °C- 140°C, and wherein the at least one diene elastomer is selected from a group consisting of polybutadiene rubber (BR), styrene-butadiene rubber (SBR), natural rubber (NR), polyisoprene, polychloroprene, hydrogenated nitrile butadiene rubber, ethylene propylene diene monomer rubber (EPDM), and combinations thereof. In another embodiment of the present disclosure, the at least one diene elastomer is a combination of polybutadiene rubber (BR), and styrene-butadiene rubber (SBR).
[0035] In an embodiment of the present disclosure, there is provided a vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy resin has a softening temperature in the range of 75 °C- 140°C, and wherein the at least one epoxy resin has a concentration in a range of 1-10 phr. In another embodiment of the present disclosure, the at least one epoxy resin has a concentration in a range of 3-8 phr. In yet another embodiment of the present disclosure, the at least one epoxy resin has a concentration in a range of 4-6 phr. [0036] In an embodiment of the present disclosure, there is provided a vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy resin has a softening temperature in the range of 75 °C- 140°C, and wherein the at least one epoxy resin has a concentration of 5 phr.
[0037] In an embodiment of the present disclosure, there is provided a vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy resin has a softening temperature in the range of 75 °C- 140°C, and wherein the at least one crosslinking agent is present in a range of 0.5 - 6.5 phr. In another embodiment of the present disclosure, the at least one crosslinking agent is present in a range of 1.0 - 6 phr. In yet another embodiment, the at least one crosslinking agent is present in a range of 1.0 - 6 phr.

[0038] In an embodiment of the present disclosure, there is provided a vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy resin has a softening temperature in the range of 75 °C- 140°C, and wherein the at least one crosslinking agent is selected from a group consisting of sulphur, peroxides, acetoxysilanes, urethanes, metal oxides, and combinations thereof. In another embodiment of the present disclosure, the at least one crosslinking agent is sulphur. [0039] In an embodiment of the present disclosure, there is provided a vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy resin has a softening temperature in the range of 75 °C- 140°C, and wherein the at least one crosslinking agent is selected from a group consisting of sulphur, peroxides, acetoxysilanes, urethanes, metal oxides, and combinations thereof, and the at least one crosslinking agent is present in a range of 0.5 - 3.2 phr. [0040] In an embodiment of the present disclosure, there is provided a vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy resin has a softening temperature in the range of 75 °C- 140°C, and wherein the composition has a rolling resistance with a tan δ value in a range of 0.100-0.120 at a temperature of 60 °C.
[0041] In an embodiment of the present disclosure, there is provided a vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; (c) at least one crosslinking agent; and (d) at least one additive selected from a group consisting of activator, processing aid, antioxidant, filler, accelerator, retarder, and combinations thereof, wherein the at least one epoxy resin has a softening temperature in the range of 75 °C- 140°C.
[0042] In an embodiment of the present disclosure, there is provided a vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; (c) at least one crosslinking agent; and (d) at least one additive selected from a group consisting of activator, processing aid, antioxidant, filler, accelerator, retarder, and combinations thereof, wherein the at least one epoxy resin has a

softening temperature in the range of 75 °C- 140°C, and wherein the activator is selected from a group consisting of zinc oxide, stearic acid, and combinations thereof, having a concentration in a range of 2 - 10 phr; the processing aid is selected from a group consisting of treated distillate aromatic extracted (TDAE) oil, aromatic oil, paraffinic oil, naphthenic oil, heavy naphthenic oil, spinder oil, residual aromatic extract (RAE), hexa methoxymethylmelamine (HMMM), cashew nut shell oil (CNSO), and combinations thereof, having a concentration in a range of 0 - 30 phr; the antioxidant is selected from a group consisting of 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ), N-(1,3-dimethylbutyl)-N'-Phenyl-p- Phenylenediamine (6 PPD), wax, and combinations thereof, having a concentration in a range of 1 - 5.5 phr; the filler is selected from a group consisting of carbon black, silica, talc, clay, calcium carbonate, carbon fibre, glass, polyester, polyamide, natural fibers, and combinations thereof, having a concentration in a range of 10 - 200 phr; the accelerator is selected from a group consisting of diphenylguanidine (DPG), N-cyclohexyl-2-benzothiazole sulfenamide (CBS), benzothiazyl disulfide (MBTS), and combinations thereof, having a concentration in a range of 0.5 - 3.2 phr; the retarder is N-cyclohexylthio-phthalimide (CTP), having a concentration in a range of 0.1 -0.9 phr. In another embodiment of the present disclosure, the processing aid is having a concentration in a range of 5-25 phr, the antioxidant is having a concentration in a range of 1-3 phr, the filler is having a concentration in a range of 70-150 phr, and the accelerator is having a concentration in a range of 0.75-1.8 phr. [0043] In an embodiment of the present disclosure, there is provided a vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy resin has a softening temperature in the range of 75 °C- 140°C, and wherein the at least one epoxy resin has a concentration in a range of 1-10 phr, and the at least one crosslinking agent is present in a range of 0.5 - 6.5 phr.
[0044] In an embodiment of the present disclosure, there is provided a vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; (c) at least one crosslinking agent; and (d) at least one additive selected from a group consisting of activator, processing aid, antioxidant, filler, accelerator,

retarder, and combinations thereof, wherein the at least one epoxy resin has a softening temperature in the range of 75 °C- 140°C, and wherein the at least one epoxy resin has a concentration in a range of 1-10 phr, and the at least one crosslinking agent is present in a range of 0.5 - 6.5 phr.
[0045] In an embodiment of the present disclosure, there is provided a vulcanized elastomer obtained from the vulcanizable elastomer as described herein. [0046] In an embodiment of the present disclosure, there is provided a vulcanized elastomer obtained from a vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; (c) at least one crosslinking agent; and (d) at least one additive selected from a group consisting of activator, processing aid, antioxidant, filler, accelerator, retarder, and combinations thereof, wherein the at least one epoxy resin has a softening temperature in the range of 75 °C- 140°C.
[0047] In an embodiment of the present disclosure, there is provided a vulcanized elastomer obtained from a vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; (c) at least one crosslinking agent; and (d) at least one additive selected from a group consisting of activator, processing aid, antioxidant, filler, accelerator, retarder, and combinations thereof, wherein the at least one epoxy resin has a softening temperature in the range of 105 °C- 130°C.
[0048] In an embodiment of the present disclosure, there is provided a vulcanized elastomer obtained from a vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy resin has a softening temperature in the range of 75 °C-140°C.
[0049] In an embodiment of the present disclosure, there is provided a vulcanized elastomer obtained from a vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy resin has a softening temperature in the range of 105 °C- 130°C.

[0050] In an embodiment of the present disclosure, there is provided a vulcanized elastomer obtained from a vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy resin has a softening temperature in the range of 75 ℃- 140℃, and the composition has a rolling resistance with a tan δ value in a range of 0.100-0.120 at a temperature of 60 ℃.
[0051] In an embodiment of the present disclosure, there is provided a vulcanized elastomer obtained from a vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy resin has a softening temperature in the range of 75 °C- 140°C and wherein the at least one epoxy resin has a concentration in a range of 1-10 phr, and the at least one crosslinking agent is present in a range of 0.5 - 6.5 phr.
[0052] In an embodiment of the present disclosure, there is provided a vulcanized elastomer obtained from a vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy resin has a softening temperature in the range of 75 ℃- 140℃, and wherein the at least one diene elastomer is selected from a group consisting of polybutadiene rubber (BR), styrene-butadiene rubber (SBR), natural rubber (NR), polyisoprene, polychloroprene, hydrogenated nitrile butadiene rubber, ethylene propylene diene monomer rubber (EPDM), and combinations thereof.
[0053] In an embodiment of the present disclosure, there is provided a vulcanized elastomer obtained from a vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; (c) at least one crosslinking agent; and (d) at least one additive selected from a group consisting of activator, processing aid, antioxidant, filler, accelerator, retarder, and combinations thereof, wherein the at least one epoxy resin has a softening temperature in the range of 75 °C- 140°C, and wherein the activator is selected from a group consisting of zinc oxide, stearic acid, and combinations thereof, having a concentration in a range of 2 - 10 phr; the processing aid is selected from a group consisting of treated distillate

aromatic extracted (TDAE) oil, aromatic oil, paraffinic oil, naphthenic oil, heavy naphthenic oil, spinder oil, residual aromatic extract (RAE), hexa methoxymethylmelamine (HMMM), cashew nut shell oil (CNSO), and combinations thereof, having a concentration in a range of 0 - 30 phr; the antioxidant is selected from a group consisting of 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ), N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6 PPD), wax, and combinations thereof, having a concentration in a range of 1 - 5.5 phr; the filler is selected from a group consisting of carbon black, silica, talc, clay, calcium carbonate, carbon fibre, glass, polyester, polyamide, natural fibers, and combinations thereof, having a concentration in a range of 10 - 200 phr; the accelerator is selected from a group consisting of diphenylguanidine (DPG), N-cyclohexyl-2-benzothiazole sulfenamide (CBS), benzothiazyl disulfide (MBTS), and combinations thereof, having a concentration in a range of 0.5 - 3.2 phr; the retarder is N-cyclohexylthio-phthalimide (CTP), having a concentration in a range of 0.1 - 0.9 phr. In another embodiment of the present disclosure, the processing aid is having a concentration in a range of 5-25 phr, the antioxidant is having a concentration in a range of 1-3 phr, the filler is having a concentration in a range of 70-150 phr, and the accelerator is having a concentration in a range of 0.75-1.8 phr.
[0054] In an embodiment of the present disclosure, there is provided a process for preparing the vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy resin has a softening temperature in the range of 75 °C- 140°C, said process comprising: (i) obtaining at least one epoxy resin; (ii) obtaining at least one diene elastomer; (iii) obtaining at least one crosslinking agent; and (iv) contacting the at least one epoxy resin, the at least one diene elastomer, and the at least one crosslinking agent, to obtain the composition. In another embodiment, the at least one epoxy resin has a softening temperature in the range of 105 °C- 130°C. [0055] In an embodiment of the present disclosure, there is provided a process for preparing the vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy resin has a softening temperature in the range of 75 °C- 140°C,

said process comprising: (i) obtaining at least one epoxy resin; (ii) obtaining at least one diene elastomer; (iii) obtaining at least one crosslinking agent; and (iv) contacting the at least one epoxy resin, the at least one diene elastomer, and the at least one crosslinking agent, to obtain the composition, and wherein the at least one diene elastomer is selected from a group consisting of polybutadiene rubber (BR), styrene-butadiene rubber (SBR), natural rubber (NR), polyisoprene, polychloroprene, hydrogenated nitrile butadiene rubber, ethylene propylene diene monomer rubber (EPDM), and combinations thereof. In another embodiment, the at least one epoxy resin has a softening temperature in the range of 105 °C- 130°C. [0056] In an embodiment of the present disclosure, there is provided a process for preparing the vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; and (c) at least one crosslinking agent, wherein the at least one epoxy resin has a softening temperature in the range of 75 °C- 140°C, said process comprising: (i) obtaining at least one epoxy resin; (ii) obtaining at least one diene elastomer; (iii) obtaining at least one crosslinking agent; and (iv) contacting the at least one epoxy resin, the at least one diene elastomer, and the at least one crosslinking agent, to obtain the composition, and wherein the at least one diene elastomer is selected from a group consisting of polybutadiene rubber (BR), styrene-butadiene rubber (SBR), natural rubber (NR), polyisoprene, polychloroprene, hydrogenated nitrile butadiene rubber, ethylene propylene diene monomer rubber (EPDM), and combinations thereof, and the at least one epoxy resin has a concentration in a range of 1-10 phr, and the at least one crosslinking agent is present in a range of 0.5 - 6.5 phr. In another embodiment, the at least one epoxy resin has a softening temperature in the range of 105 °C- 130°C. [0057] In an embodiment of the present disclosure, there is provided a process for preparing the vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; (c) at least one crosslinking agent; and (d) at least one additive selected from a group consisting of activator, processing aid, antioxidant, filler, accelerator, retarder, and combinations thereof, wherein the at least one epoxy resin has a softening temperature in the range of 75 °C- 140°C, said process comprising: (i) obtaining at least one epoxy resin; (ii) obtaining at least one

diene elastomer; (iii) obtaining at least one crosslinking agent; (iv) obtaining at least one additive; and (v) contacting the at least one epoxy resin, the at least one diene elastomer, the at least one crosslinking agent, and the at least one additive, to obtain the composition. In another embodiment, the at least one epoxy resin has a softening temperature in the range of 105 °C- 130°C.
[0058] In an embodiment of the present disclosure, there is provided a process for preparing the vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; (c) at least one crosslinking agent; and (d) at least one additive selected from a group consisting of activator, processing aid, antioxidant, filler, accelerator, retarder, and combinations thereof, wherein the at least one epoxy resin has a softening temperature in the range of 75 °C- 140°C, said process comprising: (i) obtaining at least one epoxy resin; (ii) obtaining at least one diene elastomer; (iii) obtaining at least one crosslinking agent; (iv) obtaining at least one additive; and (v) contacting the at least one epoxy resin, the at least one diene elastomer, the at least one crosslinking agent, and the at least one additive, to obtain the composition, and wherein the at least one diene elastomer is selected from a group consisting of polybutadiene rubber (BR), styrene-butadiene rubber (SBR), natural rubber (NR), polyisoprene, polychloroprene, hydrogenated nitrile butadiene rubber, ethylene propylene diene monomer rubber (EPDM), and combinations thereof. In another embodiment, the at least one epoxy resin has a softening temperature in the range of 105 °C- 130°C.
[0059] In an embodiment of the present disclosure, there is provided a process for preparing the vulcanizable elastomer composition comprising: (a) at least one epoxy resin; (b) at least one diene elastomer; (c) at least one crosslinking agent; and (d) at least one additive selected from a group consisting of activator, processing aid, antioxidant, filler, accelerator, retarder, and combinations thereof, wherein the at least one epoxy resin has a softening temperature in the range of 75 °C- 140°C, said process comprising: (i) obtaining at least one epoxy resin; (ii) obtaining at least one diene elastomer; (iii) obtaining at least one crosslinking agent; (iv) obtaining at least one additive; and (v) contacting the at least one epoxy resin, the at least one diene elastomer, the at least one crosslinking agent, and the at least one additive, to obtain

the composition, and wherein the at least one diene elastomer is selected from a group consisting of polybutadiene rubber (BR), styrene-butadiene rubber (SBR), natural rubber (NR), polyisoprene, polychloroprene, hydrogenated nitrile butadiene rubber, ethylene propylene diene monomer rubber (EPDM), and combinations thereof, and the at least one epoxy resin has a concentration in a range of 1-10 phr, and the at least one crosslinking agent is present in a range of 0.5 - 6.5 phr. In another embodiment, the at least one epoxy resin has a softening temperature in the range of 105 °C- 130°C.
[0060] Although some possible embodiments have been listed herewith but it can be contemplated that other possible embodiments are construed to be a part of the present disclosure.
EXAMPLES
[0061] The disclosure will now be illustrated with working examples, which is intended to illustrate the working of disclosure and not intended to take restrictively to imply any limitations on the scope of the present disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice of the disclosed methods and compositions, the exemplary methods, devices and materials are described herein. It is to be understood that this disclosure is not limited to particular methods, and experimental conditions described, as such methods and conditions may apply.
[0062] The present disclosure provides a vulcanizable elastomer composition (mix) comprising epoxy resin, to improve the hardness, tensile strength, elongation at break, adhesion, and decrease in tan delta (indicating lesser energy loss) of the vulcanized composition. The following examples depict the properties of vulcanized elastomer composition obtained from using different concentrations of epoxy resin along with additives as mentioned in the present disclosure. Also, examples with respect to the epoxy resin having different melting temperatures have also been disclosed herewith.

Example 1
Process for preparation of the vulcanizable elastomer composition [0063] Elastomer composition was selected containing a diene elastomer, specifically, a solution of styrene butadiene elastomer (SBR) and butadiene elastomer (BR). Furthermore, Zinc oxide (ZnO) as activator, stearic acid as processing aid, TMQ as an antioxidant, carbon black and silica as filler, silane as coupling agent for silica filler, TDAE oil (treated distillate aromatic extracted oil) as processing aid, sulphur as crosslinking agent, CBS (N-cyclohexyl-2-benzothiazole sulfenamide) and DPG (diphenylguanidine) as accelerator, and CTP (N-cyclohexylthio-phthalimide) as retarder were used. Epoxy resin was used in the composition to improve the characteristics of vulcanized elastomer obtained after vulcanizing the composition.
[0064] Kobelco intermix, Mixtron BB-L3200 IM, Kobe, Japan was employed to melt and mix the elastomer in the vulcanization mix. A fill factor (FF) of 62% was employed. The mixing was carried out in three steps; (i) preparation of master, (ii) repass, (iii) final mixing with curatives.
[0065] Step 1- Preparation of master: At first, all rubbers/elastomers were incorporated and mixed for 45 seconds at a speed of 60 rpm. Then half of all ingredients (except curative system- i.e. sulphur, CBS, DPG and CTB) were incorporated and mixed again for 60 seconds at a speed of 60 rpm. After that, remaining half of the ingredients were incorporated and mixed again for 45 seconds at a speed of 60 rpm. Finally, the mixing was continued for 240 seconds to obtain the master. At this stage, the rpm was varied to maintain the temperature at 150 ° C. [0066] Step 2- Repass: The master was kept overnight for relaxation. Next day, it was re-mixed for 210 seconds at 70 rpm.
[0067] Step 3- Final mixing with curatives: All the master and curatives were incorporated and mixed for 200 seconds to obtain the vulcanization mix. At this stage, the temperature was maintained below 100 °C through rpm control. The vulcanization mix was cured/vulcanized by thermally treating the mix at 160 °C for

T90 + 5 minutes to obtain the vulcanized elastomers (T90 is the time required to complete 90% vulcanization).
Example 2
Characterization and testing of the vulcanized elastomer [0068] After final mixing, the rheometric tests were performed at 160 °C using Moving Die Rheometer, MDR 3000, MonTech, and Mooney viscosity (ML 1+4) at 100 °C using Mooney Viscometer, and VR-1132, Ueshima, Japan. As mentioned above, the vulcanization mix was cured/vulcanized by thermally treating the mix at 160 °C for T90 + 5 minutes. Stress vs. strain and tear test was performed using Universal testing machine (UTM), Strograph AE, Toyoseiki and hardness was measured using Durometer, MonTech. FTFT test was performed using FTFT-Monsanto, SG 48, SG Electricals and Electronics, India, heat buildup was tested using Flexometer, FT-1260, Ueshima, Japan, H-adhesion test was performed using Zwick-Roell, ALLROUND Z010, Zwick, Germany, DMA test was performed using Eplexor 500N, Gabo, Germany. A tabulation of the ingredients used and various parameters established are listed below in Table 1. Study with different concentrations of EP 75 in the composition Table 1: Table listing the effect of the presence of different concentrations of EP 75 on the properties of vulcanized composition.

Step 1: M1 Quantity (phr)
RM Code i Sample No → 1 2 3 4
70.00 30.00 3.00 2.00 2.50 2.00 10.00 10.00 60.00 9.60 20.00
SBR 70.00 70.00 70.00

BR 30.00 30.00 30.00

ZnO 3.00 3.00 3.00

Stearic acid 2.00 2.00 2.00

6PPD 2.50 2.50 2.50

Wax 2.00 2.00 2.00

Epoxy (EP 75) 0.00 5.00 7.50

Carbon black 10.00 10.00 10.00

Silica 60.00 60.00 60.00

Silane coupling agent 9.60 9.60 9.60

TDAE oil 20.00 20.00 20.00

Step 2: Repass

Step 3: Final mixing with M1

Sulphur 1.818 1.818 1.818 1.818 1.400 1.800 0.200
16.09 24.20 48.99 79.97 115.31 154.78 512.4
76.5
41.35 41.70
CBS 1.400 1.400 1.400

DPG 1.800 1.800 1.800

CTP 0.200 0.200 0.200

PROPERTIES

STRESS-STRAIN

50 % MODULUS (Kg/cm2) 13.20 15.49 15.99

100 % MODULUS (Kg/cm2) 21.55 23.61 23.94

200 % MODULUS (Kg/cm2) 46.31 47.50 47.99

300 % MODULUS (Kg/cm2) 82.90 79.35 79.10

400 % MODULUS (Kg/cm2) 124.95 115.63 114.84

TENSILE STRENGTH (Kg/cm2) 159.64 165.41 152.51

ELONGATION AT BREAK (%) 481.0 535.1 504.3

HARDNESS SHORE A 66.4 74.3 75.0

Compression set (22 HR @ 70°C, 25%)

SET % MEDIAN 22.14 28.42 28.03

SET % AVERAGE 25.84 27.68 27.64

[0069] Referring to Table 1, EP 75 depicts epoxy resin with equivalent weight of 455 MW and softening point of 75oC. Sample 1 to 4 refers to absence of EP 75, presence of 5 phr of EP 75, presence of 7.5 phr of EP 75, and presence of 10 phr of EP 75 respectively. The elastomer compositions as depicted in Table 1 were used to optimize dosage of epoxy resin. It can be appreciated that hardness increased continuously with increasing concentration of EP75. The increase in hardness can be significantly observed after addition of 5 phr of EP 75 as compared to the control sample (Sample 1), whereas, increase in hardness was only marginally increased on further addition of EP 75. At 5 phr of EP 75 loading, tensile strength (TS) and elongation were increased, but TS decreased at a higher loading of EP 75. Therefore, a concentration of 5 phr loading in case of EP 75 was considered to be desirable in further analysis.
Comparative study with EP75, EP110, and EP140 in bead apex compound:
[0070] Table 2: Table listing the effect of the presence of EP 75, EP110 and EP 140 on the properties of vulcanized composition. Table 2:

R.M CODE Control EP75
(Sample
1) EP110 (Sample 2) EP140 (Sample 3)
NR (Natural rubber) 80.00 80.00 80.00 80.00
BR (polybutadiene rubber) 20.00 20.00 20.00 20.00
ZnO 7.50 7.50 7.50 7.50
Stearic acid 2.00 2.00 2.00 2.00
TMQ 2.00 2.00 2.00 2.00
PF resin 10.0 10.0 10.0 10.0
Carbon black 82 82 82 82
CNSO resin (cashew nut shell oil) 10.00 10.00 10.00 10.00
Napthenic oil 5.00 5.00 5.00 5.00
Epoxy 0.00 5.00 5.00 5.00
Step 2: Repass
Step 3: Final mixing with M1
Sulphur 5.50 5.50 5.50 5.50
DCBS 1.65 1.65 1.65 1.65
MBTS (benzothiazyl disulfide) 1.05 1.05 1.05 1.05
HMMM(hexa methoxymethylmelamine) 4.17 4.17 4.17 4.17
CTP 0.70 0.70 0.70 0.70
PROPERTIES
Stress-strain
50 % MODULUS (Kg/cm2) 53.54 57.12 57.87 65.62
100 % MODULUS (Kg/cm2) 77.19 79.47 80.99 92.58
200 % MODULUS (Kg/cm2) 132.70 127.10 130.91 140.70
TENSILE STRENGTH (Kg/cm2) 144.82 138.50 145.12 142.14
ELONGATION AT BREAK (%) 226.6 230.8 232.7 198.9

DMTA - ISO (G) (60°C)
E' (MPa) 94.495 136.2 148.55 121.907
E'' (MPa) 15.715 15.845 17.77 18.96
TAN DELTA 0.1657 0.1144 0.1196 0.160
E* (MPa) 95.78 137.1 149.65 123.5
[0071] As can be observed from Table 2, the properties of tensile strength gradually increased upon addition of EP 75 (138.50 Kg/cm2) in Sample 1 and EP 110 (145.12 Kg/cm2) in Sample 2 in respective compositions but it decreased in case of addition of EP 140 (142.14 Kg/cm2) in Sample 3. Similarly, the property of elongation at break increased upon addition of EP 75 (230.8%) in Sample 1 and EP 110 (232.7%) in Sample 2 in respective compositions but decreased in case of addition of EP 140

(198.9%) in Sample 3. It can also be noted that Tan delta value decreased upon addition of EP 75 (Sample 1) and EP 110 (Sample 2) which was desirable, however, upon addition of EP 140 (Sample 3) Tan delta value increased to 0.160 which was not desirable because it would increase the rolling resistance. [0072] The properties of the vulcanized composition comprising EP 75 and EP 110 exhibited better properties as compared to EP 140. Among the compositions comprising EP 75 and EP 110, the composition comprising EP 110 showed desirable properties in terms of having increased tensile strength and elongation at break and having a comparable Tan delta value. The vulcanized composition comprising epoxy having softening point higher than 140℃ was found to be difficult to process as it led to problems with respect to mixing.
[0073] Therefore, it can be summarized that vulcanized elastomer composition comprising individually EP 75, EP 110, and EP 140 were desirable in terms of the tensile strength, hardness, and tan delta value. The lower Tan delta value would assist in providing lower rolling resistance which is desirable. The composition comprising EP 140 although provided better tensile strength but lead to a compromised Tan delta value which is not desirable. Thus, vulcanized elastomer composition comprising individually EP 75, EP 110, and EP 140 when forms a part of bead apex provides tire having desirable properties. Specifically, vulcanized elastomer composition comprising EP 110 displayed desirable properties as compared to other compositions.
Advantages of the present disclosure:
[0074] The present disclosure discloses vulcanizable elastomer composition comprising epoxy resin, diene elastomer, and crosslinking agent. The composition of the present disclosure comprises at least one epoxy resin, at least one diene elastomer, and at least one crosslinking agent, wherein the at least one epoxy resin has a softening temperature in a range of 75-140℃. The composition comprising epoxy resin, particularly epoxy resin having softening temperature in a range of 105-130℃ provides increased hardness, higher elongation at break, and lower rolling resistance while maintaining other attributes of the vulcanized composition. The addition of epoxy resin helps in providing higher quality tires without adding to the

manufacturing costs, thus providing economic benefit in arriving at a high-quality tire.

I/We Claim:
1. A vulcanizable elastomer composition comprising:
a) at least one epoxy resin;
b) at least one diene elastomer; and
c) at least one crosslinking agent,
wherein the at least one epoxy resin has a softening temperature in the range of 75 ℃- 140℃.
2. The vulcanizable elastomer composition as claimed in claim 1, wherein the at least one epoxy resin has a softening temperature in the range of 75 ℃-130℃.
3. The composition as claimed in claim 1, wherein the at least one diene elastomer is selected from a group consisting of polybutadiene rubber (BR), styrene-butadiene rubber (SBR), natural rubber (NR), polyisoprene, polychloroprene, hydrogenated nitrile butadiene rubber, ethylene propylene diene monomer rubber (EPDM), and combinations thereof.
4. The composition as claimed in claim 1, wherein the at least one epoxy resin has a concentration in a range of 1-10 phr.
5. The composition as claimed in claim 1, wherein the at least one crosslinking agent is present in a range of 0.5 - 6.5 phr.
6. The composition as claimed in claim 1, wherein the at least one crosslinking agent is selected from a group consisting of sulphur, peroxides, acetoxysilanes, urethanes, metal oxides, and combinations thereof.
7. The composition as claimed in claim 1, wherein the vulcanizable elastomer composition further comprises at least one additive selected from a group consisting of activator, processing aid, antioxidant, filler, accelerator, retarder, and combinations thereof.
8. The composition as claimed in claim 1, wherein the vulcanizable elastomer composition has a rolling resistance with a tan δ value in a range of 0.100-0.120 at a temperature of 60 ℃.
9. The composition as claimed in claim 7, wherein the activator is selected from a group consisting of zinc oxide, stearic acid, and combinations thereof,

having a concentration in a range of 2 – 10 phr; the processing aid is selected from a group consisting of treated distillate aromatic extracted (TDAE) oil, aromatic oil, paraffinic oil, naphthenic oil, heavy naphthenic oil, spinder oil, residual aromatic extract (RAE), hexa methoxymethylmelamine (HMMM), cashew nut shell oil (CNSO), and combinations thereof, having a concentration in a range of 0 – 30 phr; the antioxidant is selected from a group consisting of 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ), N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6 PPD), wax, and combinations thereof, having a concentration in a range of 1 – 5.5 phr; the filler is selected from a group consisting of carbon black, silica, talc, clay, calcium carbonate, carbon fibre, glass, polyester, polyamide, natural fibers, and combinations thereof, having a concentration in a range of 10 – 200 phr; the accelerator is selected from a group consisting of diphenylguanidine (DPG), N-cyclohexyl-2-benzothiazole sulfenamide (CBS), benzothiazyl disulfide (MBTS), and combinations thereof, having a concentration in a range of 0.5 – 3.2 phr; the retarder is N-cyclohexylthio-phthalimide (CTP), having a concentration in a range of 0.1 – 0.9 phr.
10. A vulcanized elastomer obtained from the vulcanizable elastomer composition as claimed in any one of the claims 1-9.
11. A process for preparing the vulcanizable elastomer composition as claimed in claim 1, said process comprising:

a) obtaining at least one epoxy resin;
b) obtaining at least one diene elastomer;
c) obtaining at least one crosslinking agent; and
d) contacting the at least one epoxy resin, the at least one diene elastomer, and the at least one crosslinking agent, to obtain the vulcanizable elastomer composition.
12. A process for preparing the vulcanizable elastomer composition as claimed
in claim 7, said process comprising:
a) obtaining at least one epoxy resin
b) obtaining at least one diene elastomer;

c) obtaining at least one crosslinking agent;
d) obtaining at least one additive; and
e) contacting the at least one epoxy resin, the at least one diene elastomer, the at least one crosslinking agent, and the at least one additive, to obtain the vulcanizable elastomer composition.