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: A FLAP RUBBER COMPOSITION, AND IMPLEMENTATIONS
THEREOF
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 for tire flaps and in particular relates to a flap rubber composition so as to provide means for extending the service life of the tire. BACKGROUND OF INVENTION
[0002] Flap is an integral part of tube-type tires which is fitted in combination with tube and tire in the vehicle. The flap is the interference between the rim and the tube of a tire which protects tire tube from damage against the rim.
[0003] The tire tube which is mostly made up of butyl rubber is designed to maintain the air pressure within the tire, while the flap protects the tire tube from chafing with the rim and prevents it from being pushed under the bead toe. A proper selection of the flap composition is therefore essential in order to ensure increased performance of the tube-type tires.
[0004] Various flap compositions are known in the art. JP2010275359A provides a pneumatic tire with a flap obtained from rubber composition which suppresses reversion. CN107200885A provides a rubber composition obtained from recycled rubber composition that improves the tensile strength and hardness of the tire. US20180186973A1 provides pneumatic tires obtained from rubber composition that
can exhibit rim chafing resistance and antistatic properties for a long time while maintaining or improving good low heat build-up properties. [0005] The flap currently used in the tires, cuts the tire tube at the edge of the flap. This leads to tire tube failure during service life tire in the field and results in customer s dissatisfaction, as they eventually need to change the tire tube for further
running of the vehicle.
[0006] In view of the above, there is a need in the art to obtain flap compositions that eliminate tube failure.
SUMMARY OF THE INVENTION
[0007] In an aspect of the present disclosure, there is provided a flap rubber
composition comprising: a) 20 - 60 phr of at least one recycled rubber component;
b) 35 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural

rubber component; d) 20 - 45 phr of at least one secondary grade carbon black; e)
1.0 1.6 phr of at least one crosslinking agent; and f) 0.5 - 2.0 phr of at least one
accelerator.
[0008] In another aspect of the present disclosure, there is provided a process for
preparation of the flap rubber composition comprising: a) 20 - 60 phr of at least one recycled rubber component; b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one secondary grade carbon black; e) 1.0 - 1.6 phr of at least one crosslinking agent; and f) 0.5 - 2.0 phr of at least one accelerator, said process comprising: a) contacting the at least one
recycled rubber component, the styrene-butadiene rubber, the at least one natural rubber component, and the at least one secondary grade carbon black, to obtain a first mixture; b) contacting the first mixture with the at least one crosslinking agent, and the at least one accelerator for a period in a range of 2 - 4 minutes carried out at a temperature in a range of 100°C - 110°C to obtain the second mixture; and c)
processing the second mixture to obtain the flap rubber composition.
[0009] In yet another aspect of the present disclosure, there is provided a process for preparation of the flap rubber composition comprising: a) 20 - 60 phr of at least one recycled rubber component; b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one secondary
grade carbon black; e) 1.0 - 1.6 phr of at least one crosslinking agent; and f) 0.5 - 2.0 phr of at least one accelerator, said process comprising: a) contacting the at least one recycled rubber component, the styrene-butadiene rubber, the at least one natural rubber component, the at least one secondary grade carbon black, the at least one primary grade carbon black, activator, processing aid, and antioxidant to obtain a
third mixture; b) contacting the third mixture with the at least one crosslinking agent, and the at least one accelerator for a period in a range of 2 - 4 minutes carried out at a temperature in a range of 100°C - 110°C to obtain the fourth mixture; and c) processing the fourth mixture to obtain the flap rubber composition. [0010] In a further aspect of the present disclosure, there is provided a tire having a
flap fabricated using the flap rubber composition comprising: a) 20 - 60 phr of at least one recycled rubber component; b) 35 - 60 phr of styrene-butadiene rubber; c)

15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one secondary grade carbon black; e) 1.0 - 1.6 phr of at least one crosslinking agent; and f) 0.5 - 2.0 phr of at least one accelerator.
[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 temperature range of about 160-180°C should be interpreted to include not only the explicitly recited limits of about 160°C to about 180°C, but also to include sub-ranges, such as 160-170°C, 165-175°C, and so forth, as well as individual amounts, including fractional amounts, within the specified ranges, such as 160.2 °C, and 179.5 °C, for example.
[0019] The term room temperature is used to denote a temperature range of about 25°C to about 35°C.
[0020] The term flap growth refers to the growth (in the transverse direction) of the tire flap, i.e, when the flap undergoes endurance test either indoor or in the field when the tire is running, the growth which happens in the transverse direction is referred to as flap growth. The calculation of the flap growth in percent is provided in the disclosure.
[0021] The term at least one is used to mean one or more and thus includes individual components as well as mixtures/combinations.
[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] As mentioned previously, there is a need to eliminate the failure in tire tubes, so that prolonged service life of the tire is achieved. The same is accomplished by strengthening the flap by means of the rubber composition comprising a) 20 - 60 phr of at least one recycled rubber component; b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one
secondary grade carbon black; e) 1.0 - 1.6 phr of at least one crosslinking agent; and f) 0.5 - 2.0 phr of at least one accelerator. The flap rubber composition of the present disclosure adapts itself to the mechanical strains occurring in flap during endurance test that there is no need to reinforce the affected region by an increase in the thickness of the flap or by the addition of extra sheet material. The flap prepared
from the flap rubber composition of the present disclosure is easier to build and is cost-effective as well. The present disclosure provides a flap rubber composition which overcomes the problems associated with flap compositions and thus ensures the increased performance of the tube-type tire tires. [0025] In an embodiment of the present disclosure, there is provided a flap rubber
composition comprising: a) 20 - 60 phr of at least one recycled rubber component; b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one secondary grade carbon black; e) 1.0 - 1.6 phr of at least one crosslinking agent; and f) 0.5 - 2.0 phr of at least one accelerator. [0026] In an embodiment of the present disclosure, there is provided a flap rubber
composition comprising: a) 30 - 50 phr of at least one recycled rubber component; b) 40 - 55 phr of styrene-butadiene rubber; c) 25 - 35 phr of at least one natural rubber component; d) 25 - 35 phr of at least one secondary grade carbon black; e) 1.1 - 1.4 phr of at least one crosslinking agent; and f) 0.5 - 1.5 phr of at least one accelerator. [0027] In an embodiment of the present disclosure, there is provided a flap rubber
composition as described herein, wherein the at least one recycled rubber component is selected from the group consisting of the whole tire reclaim rubber, 80 mesh crumb

rubber, and combinations thereof. In another embodiment of the present disclosure, the at least one recycled rubber component is the whole tire reclaim rubber. [0028] In an embodiment of the present disclosure, there is provided a flap rubber composition comprising: a) 20 - 60 phr of at least one recycled rubber component
selected from the group consisting of the whole tire reclaim rubber, 80 mesh crumb rubber, and combinations thereof; b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one secondary grade carbon black; e) 1.0 - 1.6 phr of at least one crosslinking agent; and f) 0.5 - 2.0 phr of at least one accelerator.
[0029] In an embodiment of the present disclosure, there is provided a flap rubber composition as described herein, wherein the at least one natural rubber component is selected from the group consisting of RSS3, RSS4, TSR10, TSR20, and combinations thereof. In another embodiment of the present disclosure, the at least one natural rubber component is TSR20.
[0030] In an embodiment of the present disclosure, there is provided a flap rubber composition comprising: a) 20 - 60 phr of at least one recycled rubber component; b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component selected from the group consisting of RSS3, RSS4, TSR10, TSR20, and combinations thereof; d) 20 - 45 phr of at least one secondary grade carbon black; e)
1.0 - 1.6 phr of at least one crosslinking agent; and f) 0.5 - 2.0 phr of at least one accelerator.
[0031] In an embodiment of the present disclosure, there is provided a flap rubber composition as described herein, wherein the at least one secondary grade carbon black has a surface area in the range of 77 - 87 mg/g and is selected from the group
consisting of N330, N358, N326, and combinations thereof. In another embodiment of the present disclosure, the at least one secondary grade carbon black has a surface area in the range of 80 -84 mg/g.
[0032] In an embodiment of the present disclosure, there is provided a flap rubber composition comprising: a) 20 - 60 phr of at least one recycled rubber component;
b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one secondary grade carbon black having a

surface area in the range of 77 - 87 mg/g and selected from the group consisting of N330, N358, N326, and combinations thereof; e) 1.0 - 1.6 phr of at least one crosslinking agent; and f) 0.5 - 2.0 phr of at least one accelerator. [0033] In an embodiment of the present disclosure, there is provided a flap rubber composition as described herein, wherein the at least one crosslinking agent is selected from sulphur, accelerators, and combinations thereof. In another embodiment of the present disclosure, the at least one cross-linking agent is sulfur. [0034] In an embodiment of the present disclosure, there is provided a flap rubber composition comprising: a) 20 - 60 phr of at least one recycled rubber component; b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one secondary grade carbon black; e) 1.0 - 1.6 phr of at least one crosslinking agent selected from sulphur, accelerators, and combinations thereof; and f) 0.5 - 2.0 phr of at least one accelerator. [0035] In an embodiment of the present disclosure, there is provided a flap rubber composition as described herein, wherein the at least one accelerator is selected from the group consisting of 2-2'-dithiobis(benzothiazole) (MBTS), N-oxydiethylene-2-benzothiazole sulphonamide (NOBS), tetramethylthiuram disulfide (TMTD), and combinations thereof.
[0036] In an embodiment of the present disclosure, there is provided a flap rubber composition comprising: a) 20 - 60 phr of at least one recycled rubber component; b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one secondary grade carbon black; e) 1.0 - 1.6 phr of at least one crosslinking agent; and f) 0.5 - 2.0 phr of at least one accelerator selected from the group consisting of 2-2'-dithiobis(benzothiazole) (MBTS), N- oxydiethylene-2-benzothiazole sulphonamide (NOBS), tetramethylthiuram disulfide (TMTD), and combinations thereof.
[0037] In an embodiment of the present disclosure, there is provided a flap rubber composition as described herein, wherein the composition further comprises at least one primary grade carbon black having a concentration in a range of 5 - 30 phr. In another embodiment of the present disclosure, the at least one primary grade carbon black has a concentration in a range of 5 - 15 phr.

[0038] In an embodiment of the present disclosure, there is provided a flap rubber composition comprising: a) 20 - 60 phr of at least one recycled rubber component; b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one secondary grade carbon black; e) 1.0 - 1.6 phr of at least one crosslinking agent; f) 0.5 - 2.0 phr of at least one accelerator; and g) 5 - 30 phr of at least one primary grade carbon black.
[0039] In an embodiment of the present disclosure, there is provided a flap rubber composition as described herein, wherein the at least one primary grade carbon black has a surface area in the range of 31 - 41 mg/g and is selected from the group
consisting of N660, N630, N642, N650, N683, and combinations thereof. In another embodiment of the present disclosure, the at least one primary grade carbon black has a surface area in the range of 34 - 38 mg/g.
[0040] In an embodiment of the present disclosure, there is provided a flap rubber composition comprising: a) 20 - 60 phr of at least one recycled rubber component;
b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one secondary grade carbon black; e) 1.0 - 1.6 phr of at least one crosslinking agent; f) 0.5 - 2.0 phr of at least one accelerator; and g) 5 - 30 phr of at least one primary grade carbon black having a surface area in the range of 31 - 41 mg/g and selected from the group consisting of N660, N630, N642,
N650, N683, and combinations thereof.
[0041] In an embodiment of the present disclosure, there is provided a flap rubber composition as described herein, wherein the flap rubber composition optionally comprises at least one additive selected from the group consisting of activator, processing aid, antioxidant, and combinations thereof.
[0042] In an embodiment of the present disclosure, there is provided a flap rubber composition comprising: a) 20 - 60 phr of at least one recycled rubber component; b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one secondary grade carbon black; e) 1.0 - 1.6 phr of at least one crosslinking agent; f) 0.5 - 2.0 phr of at least one accelerator; g) 5
- 30 phr of at least one primary grade carbon black; and h) at least one additive

selected from the group consisting of activator, processing aid, antioxidant, and combinations thereof.
[0043] In an embodiment of the present disclosure, there is provided a flap rubber composition comprising: a) 20 - 60 phr of at least one recycled rubber component; b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one secondary grade carbon black; e) 1.0 - 1.6 phr of at least one crosslinking agent; f) 0.5 - 2.0 phr of at least one accelerator; g) 5
- 30 phr of at least one primary grade carbon black; and h) activator.
[0044] In an embodiment of the present disclosure, there is provided a flap rubber
composition comprising: a) 20 - 60 phr of at least one recycled rubber component; b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one secondary grade carbon black; e) 1.0 - 1.6 phr of at least one crosslinking agent; f) 0.5 - 2.0 phr of at least one accelerator; g) 5
- 30 phr of at least one primary grade carbon black; h) activator; and i) processing
aid.
[0045] In an embodiment of the present disclosure, there is provided a flap rubber composition comprising: a) 20 - 60 phr of at least one recycled rubber component; b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one secondary grade carbon black; e) 1.0 - 1.6 phr of at least one crosslinking agent; f) 0.5 - 2.0 phr of at least one accelerator; g) 5
- 30 phr of at least one primary grade carbon black; h) activator; i) processing aid;
and j) antioxidant.
[0046] In an embodiment of the present disclosure, there is provided a flap rubber composition as described herein, wherein the activator has a concentration in a range
of 2 - 4 phr, and is selected from the group consisting of zinc oxide, nano zinc oxide, zinc monomethacrylate, and combinations thereof; the processing aid has a concentration in a range of 1.0 - 20 phr, and is selected from the group consisting of steric acid, treated distillate aromatic extracted (TDAE) oil, aromatic oil, paraffinic oil, naphthenic oil, heavy naphthenic oil, residual aromatic extract (RAE), and
combinations thereof; the antioxidant has a concentration in a range of 0.5 - 3.5 phr, and is selected from the group consisting of N-(1,3-dimethylbutyl)-N-phenyl-p-

phenylenediamine (6PPD), wax, 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ), 1,2-
dihydro-2,2,4-trimethylquinoline (TMDQ) N-isopropyl-N-phenyl-P-
phenylenediamine (IPPD), and combinations thereof.
[0047] In an embodiment of the present disclosure, there is provided a flap rubber composition comprising: a) 20 - 60 phr of at least one recycled rubber component; b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one secondary grade carbon black; e) 1.0 - 1.6 phr of at least one crosslinking agent; f) 0.5 - 2.0 phr of at least one accelerator; g) 5
- 30 phr of at least one primary grade carbon black; and h) at least one additive
selected from the group consisting of activator, processing aid, antioxidant, and
combinations thereof, wherein the activator has a concentration in a range of 2 - 4
phr, and is selected from the group consisting of zinc oxide, nano zinc oxide, zinc
monomethacrylate, and combinations thereof; the processing aid has a concentration
in a range of 1.0 - 20 phr, and is selected from the group consisting of steric acid,
treated distillate aromatic extracted (TDAE) oil, aromatic oil, paraffinic oil,
naphthenic oil, heavy naphthenic oil, residual aromatic extract (RAE), and
combinations thereof; the antioxidant has a concentration in a range of 0.5 - 3.5 phr,
and is selected from the group consisting of N-(1,3-dimethylbutyl)-N-phenyl-p-
phenylenediamine (6PPD), wax, 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ), 1,2-
dihydro-2,2,4-trimethylquinoline (TMDQ) N-isopropyl-N-phenyl-P-
phenylenediamine (IPPD), and combinations thereof.
[0048] In an embodiment of the present disclosure, there is provided a flap rubber composition comprising: a) 20 - 60 phr of at least one recycled rubber component; b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one secondary grade carbon black; e) 1.0 - 1.6 phr of at least one crosslinking agent; f) 0.5 - 2.0 phr of at least one accelerator; g) 5
- 30 phr of at least one primary grade carbon black; h) 2 - 4 phr of activator; i) 1.0 -
20 phr of processing aid; and j) 0.5 - 3.5 phr of antioxidant.
[0049] In an embodiment of the present disclosure, there is provided a flap rubber
composition as described herein, wherein the composition has a flap growth in a range of 12 -15%. In another embodiment of the present disclosure, the composition

has a flap growth in a range of 12 - 14%. In yet another embodiment of the present disclosure, the composition has a flap growth of 13%.
[0050] In an embodiment of the present disclosure, there is provided a flap rubber composition as described herein, wherein the composition has 300 % modulus in a range of 70 - 95 kg/cm2 at room temperature.
[0051] In an embodiment of the present disclosure, there is provided a flap rubber composition as described herein, wherein the composition has a hardness in a range of 56 - 58 at room temperature. [0052] In an embodiment of the present disclosure, there is provided a process for
preparation of the flap rubber composition comprising: a) 20 - 60 phr of at least one recycled rubber component; b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one secondary grade carbon black; e) 1.0 - 1.6 phr of at least one crosslinking agent; and f) 0.5 - 2.0 phr of at least one accelerator, said process comprising: a) contacting the at least one
recycled rubber component, the styrene-butadiene rubber, the at least one natural rubber component, and the at least one secondary grade carbon black, to obtain a first mixture; b) contacting the first mixture with the at least one crosslinking agent, and the at least one accelerator for a period in a range of 2 - 4 minutes carried out at a temperature in a range of 100°C - 110°C to obtain the second mixture; and c)
processing the second mixture to obtain the flap rubber composition.
[0053] In an embodiment of the present disclosure, there is provided a process for preparation of the flap rubber composition comprising: a) 20 - 60 phr of at least one recycled rubber component; b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one secondary
grade carbon black; e) 1.0 - 1.6 phr of at least one crosslinking agent; f) 0.5 - 2.0 phr of at least one accelerator; g) 5 - 30 phr of at least one primary grade carbon black; and h) at least one additive selected from the group consisting of activator, processing aid, antioxidant, and combinations thereof, said process comprising: a) contacting the at least one recycled rubber component, the styrene-butadiene rubber,
the at least one natural rubber component, and the at least one secondary grade carbon black, to obtain a first mixture; b) contacting the first mixture with the at least

one crosslinking agent, and the at least one accelerator for a period in a range of 2 -4 minutes carried out at a temperature in a range of 100°C - 110°C to obtain the second mixture; and c) processing the second mixture to obtain the flap rubber composition. [0054] In an embodiment of the present disclosure, there is provided a process for preparation of the flap rubber composition comprising: a) 20 - 60 phr of at least one recycled rubber component; b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one secondary grade carbon black; e) 1.0 - 1.6 phr of at least one crosslinking agent; and f) 0.5 - 2.0
phr of at least one accelerator, said process comprising: a) contacting the at least one recycled rubber component, the styrene-butadiene rubber, the at least one natural rubber component, the at least one secondary grade carbon black, the at least one primary grade carbon black, activator, processing aid, and antioxidant to obtain a third mixture; b) contacting the third mixture with the at least one crosslinking agent,
and the at least one accelerator for a period in a range of 2 - 4 minutes carried out at a temperature in a range of 100°C - 110°C to obtain the fourth mixture; and c) processing the fourth mixture to obtain the flap rubber composition. [0055] In an embodiment of the present disclosure, there is provided a process for preparation of the flap rubber composition comprising: a) 20 - 60 phr of at least one
recycled rubber component; b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one secondary grade carbon black; e) 1.0 - 1.6 phr of at least one crosslinking agent; f) 0.5 - 2.0 phr of at least one accelerator; g) 5 - 30 phr of at least one primary grade carbon black; and h) at least one additive selected from the group consisting of activator,
processing aid, antioxidant, and combinations thereof, said process comprising: a) contacting the at least one recycled rubber component, the styrene-butadiene rubber, the at least one natural rubber component, the at least one secondary grade carbon black, the at least one primary grade carbon black, activator, processing aid, and antioxidant to obtain a third mixture; b) contacting the third mixture with the at least
one crosslinking agent, and the at least one accelerator for a period in a range of 2 -4 minutes carried out at a temperature in a range of 100°C - 110°C to obtain the

fourth mixture; and c) processing the fourth mixture to obtain the flap rubber composition.
[0056] In an embodiment of the present disclosure, there is provided a process for preparation of the flap rubber composition comprising: a) 20 - 60 phr of at least one recycled rubber component; b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one secondary grade carbon black; e) 1.0 - 1.6 phr of at least one crosslinking agent; and f) 0.5 - 2.0 phr of at least one accelerator, said process comprising: processing the second mixture or the fourth mixture to obtain the flap rubber composition by the process
comprising: a) extruding the second mixture in an extruder for a period in a range of 110°C - 125°C to obtain a extruded product; and b) curing the extruded product to obtain the flap rubber composition.
[0057] In an embodiment of the present disclosure, there is provided a process for preparation of the flap rubber composition as described herein, wherein curing the
extruded product to obtain the flap rubber composition is carried out at a temperature in a range of 160 - 180 °C for a period in a range of 2 - 5 minutes. [0058] In an embodiment of the present disclosure, there is provided a tire having a flap fabricated using the flap rubber composition comprising: a) 20 - 60 phr of at least one recycled rubber component; b) 35 - 60 phr of styrene-butadiene rubber; c)
15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one secondary grade carbon black; e) 1.0 - 1.6 phr of at least one crosslinking agent; and f) 0.5 - 2.0 phr of at least one accelerator.
[0059] In an embodiment of the present disclosure, there is provided a tire having a flap fabricated using the flap rubber composition comprising: a) 20 - 60 phr of at
least one recycled rubber component; b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one secondary grade carbon black; e) 1.0 - 1.6 phr of at least one crosslinking agent; f) 0.5 - 2.0 phr of at least one accelerator; g) 5 - 30 phr of at least one primary grade carbon black; and h) at least one additive selected from the group consisting of
activator, processing aid, antioxidant, and combinations thereof.

[0060] Although the subject matter has been described in considerable detail with reference to certain preferred embodiments thereof, other embodiments are possible.
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 flap rubber composition comprising 20 -60 phr of at least one recycled rubber component, 35 - 60 phr of styrene-butadiene rubber, 15 - 40 phr of at least one natural rubber component, 20 - 45 phr of at least one secondary grade carbon black, 1.0 - 1.6 phr of at least one crosslinking agent and 0.5 - 2.0 phr of at least one accelerator, which strengthens the flap of the tire, thereby
prolonging the service life of the tire. The flap composition also includes at least one primary grade carbon black having a concentration in a range of 5 - 30 phr. It is the usage of less concentration of carbon black (two different grades N-330 and N-660) along with the high amount of recycled material and oil which maintains the modulus and helps in the growth of flap transversally.
[0063] Various flap compositions were prepared, i.e., EX1 to EX4, wherein the composition comprises (a) 30 - 50 phr of the whole tire reclaim rubber (at least one recycled rubber component); (b) 40 - 55 phr of SBR-1502 (styrene-butadiene rubber); (c) 25 - 35 phr of TSR20 (at least one natural rubber component); (d) 25 -35 phr of N-330 (at least one secondary grade carbon black); (e) 1 phr of sulfur (at
least one crosslinking agent); (f) 1 phr of N-oxydiethylene-2-benzothiazole sulphonamide (NOBS) and 0 -1 phr of tetramethylthiuram disulfide (TMTD) (at least

one accelerator); (g) 5 - 15 phr of N-660 (at least one primary grade carbon black); (h) 2 - 3 phr of zinc oxide (activator); (i) 1 - 2 phr of stearic acid (processing aid); (j) 1 phr of N-(1,3-dimethylbutyl)-N-phenyl-p-phenylenediamine (6PPD), 1 - 2 phr of wax (microcrystalline), and 1 -3 phr of 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ) as antioxidants; and (k) 8 - 35 phr of aromatic oil.
Materials and methods
Grades of the raw material used in the flap rubber composition [0064] The grades and the make of various components used in the present disclosure are as follows:
a) at least one recycled rubber component: Whole tire reclaim was procured from Gujarat Rubber Reclaim (GRRP) having a tensile strength of 5.0 MPa.
b) styrene-butadiene rubber: SBR-Kumho 1502 was procured from Kumho.
c) at least one natural rubber component: TSR20 - Standard Thailand Rubber - 20
was procured from Thailand.
d) at least one secondary grade carbon black: N330 was procured from PCBL (Phillips Carbon Black Limited), India
e) at least one crosslinking agent: Sulphur was procured from Jaishil Industries, India.
f) accelerators: MBTS, NOBS, TMTD were procured from Nocil Limited. and Lanxess India. g) at least one primary grade carbon black: N660 from PCBL, India
Example 1: Process for the preparation of the flap rubber composition 1
[0065] The flap rubber composition of the present disclosure was prepared in a traditionally used machine for mixing rubber compounds. Mixing of the components
was done in a Banbury mixer and then the mix was sheeted out through a two-roll
mill.
[0066] The process was performed by a two-step mixing in Banbury mill. The first
step included the masterbatch mixing of the whole tire reclaim rubber (the at least one recycled rubber component), SBR-1502 (the styrene-butadiene rubber), TSR-20
(the at least one natural rubber component), and N-330 (the at least one secondary

grade carbon black), to obtain a first mixture. The first mixture obtained from the first step was further mixed with sulphur and 2-2'-dithiobis(benzothiazole), N-oxydiethylene-2- benzothiazole sulphonamide, and tetramethylthiuram disulfide (at least one accelerator) for a period in a range of 2 - 4 minutes and the temperature was maintained in a range of 100°C - 110 °C to obtain the second mixture. The second mixture was further processed in a twin-screw sheeter and extruded to form a Slug (extruded product). The critical parameters of the process were the mixing time (2-4 mins), temperature (100 °C-110 °C) and viscosity (40-50 Mooney) in the mixer. The extruded slug was kept for minimum of 4 hrs, before curing. The curing of the flap rubber composition of the present composition was performed by compression molding. The extruded slug is loaded in the mold cavity, and curing is completed in 4.5 mins at a temperature of 170 °C.
Example 2: Process for the preparation of the flap rubber composition 2 [0067] The flap composition was prepared by adding 50 phr of the whole tire
reclaim rubber, 47 phr of SBR-1502, 28 phr of TSR-20 and N-330, 3 phr of zinc oxide, 2 phr of stearic acid, 3 phr of TMQ, 1 phr of wax and 6PPD in the Banbury mill and mixing the components to obtain a third mixture. The third mixture is further mixed with 1 phr of sulfur, NOBS and TMTD at a temperature in a range of 100°C - 110°C for 2-4 minutes. This resulted in the formation of a fourth mixture which
was further processed. The processing of the fourth mixture involved extruding the fourth mixture in a twin-screw sheeter to obtain an extruded product (slug) in the form of a 6mm sheet. The extruded slug was kept for minimum of 4 hrs, before curing. [0068] The curing of the flap rubber composition of the present composition was
performed by compression molding. The extruded slug is loaded in the mold cavity and curing is completed in 4.5 mins at a temperature of 170 °C. The flap rubber composition of the present disclosure was obtained in the form of a flap after extrusion and compression molding. The resultant flap showed a 300% modulus of elasticity which was 80 kg/cm2 at room temperature. Further, the hardness of the flap
was found to be 57 Shore A (hardness calculated with Shore A scale) at room

temperature. The flap obtained from the above-mentioned process can further be used to fabricate a tire.
Example 3: Growth check for the flap rubber composition [0069] The growth check endurance test was carried on the cured flap (obtained from the above-mentioned process) of tube type radial truck tire. Before carrying out the endurance test, the flap dimensions were checked and noted. After completion of the endurance test, the flap was removed from the tire and the dimensions were checked again. Change in dimensions (before and after carrying out the test) in the transverse direction was considered as the growth in the flap. [0070] The formula used for calculating the percentage flap growth is as follows:

wherein X = Fresh flap width in mm
Y= Flap width after carrying out an endurance test in mm
Four compositions (EX1 to EX4) along with a reference composition (R) were prepared in the form of a flap in accordance to the process described in the preceding paragraphs. Various flap prepared from the flap rubber composition mentioned in EX 1 to EX 4 were tested indoor in order to check the growth compared to a reference flap. Flaps showing higher growth indoor were further tested in the field as well (by
using the flap in a running tire) to check the tube failure during the service condition. The components and their concentrations (in phr) along with the flap growth test results are illustrated in Table 1 for various compositions.
Table 1. Table listing various components of the flap compositions and their concentration along with flap growth evaluation results

Components Range of
components
(phr) R
30 EX1
15 EX2
30 EX3
40 EX4
28
TSR-20 (at least one natural rubber component) 25-35

SBR-1502 (styrene-butadiene rubber) 40-55 53
35
4 2
3 1
1
10
51
25 1
1 0 64
42
4 2
1 1
60
35 1
0 40 30 60
3 2
3 1
1 38
8 1
1 47
50
3 2
3 1
1
10
28
10 1
1
High tensile reclaim rubber (7.5MPa tensile strength) (at least one recycled rubber component) 30-50

60

Whole tire reclaim rubber (5.0MPa TS) (at least one recycled rubber component) 30-50

ZnO (activator) 2-3

3

Stearic acid (processing aid) 1-2

2

TMQ (2,2,4-trimethyl-1,2-dihydroquinoline; antioxidant) 2-3.5

3

MC (microcrystalline) Wax (antioxidant) 1.75-2.25

2

6PPD (N-(1,3-dimethylbutyl)-N-phenyl-p-phenylenediamine; antioxidant) 0.5-1.25

1

Clay

5

N-660 (at least one primary grade carbon black) 5-15

37

N-330(at least one secondary grade carbon black) 25-35

Aromatic oil (processing aid) 5-15

8

Sulphur (at least one crosslinking agent) 1.1-1.4

1

MBTS (2-2'-dithiobis(benzothiazole); at least one accelerator) 0.7-1.0

NOBS (N-oxydiethylene-2-benzothiazole 0.5-2.0

1

sulphonamide; at least one accelerator) 1
215 7.3 1
226 7.6 0
192 10.7 0
187 7 1
185 13
TMTD (tetramethylthiuram disulfide; at least one accelerator) 0.5-0.7

Total concentration in phr -

Flap growth percent -

[0071] Table 1 illustrates flaps obtained from four flap compositions EX1 to EX4 mentioned earlier. It can be inferred from Table 1 that maximum flap growth was achieved in the case of EX4, wherein all the components are within the disclosed
concentrations. The reference s flap growth (R) was found to be 7.3%, and the flap growth percentage calculated for EX1, EX2, EX3 was 7.6%, 10.7%, and 7% respectively. These examples as depicted in Table 1 highlight the criticality of the components in a specified concentration in achieving a flap for tube-type radial truck tire from the flap rubber composition of the present disclosure
[0072] As seen in Table 1 above, it is concluded that the flap EX4 comprising the flap rubber composition according to the present disclosure shows the highest flap growth, and thus would result in strengthening the flap. The tire flap comprising the flap rubber composition of the present disclosure adapts itself to the mechanical strains and thus provides additional capacity and reinforcement to the tire. The tire
flap obtained from the flap rubber composition of the present disclosure helps in increasing the life of the tire tube, and the whole tire.
Advantages of the present disclosure:
[0073] The present disclosure reveals a flap rubber composition comprising: a) 20 - 60 phr of at least one recycled rubber component; b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component; d) 20 - 45 phr of at least one secondary grade carbon black; e) 1.0 - 1.6 phr of at least one crosslinking agent; and f) 0.5 - 2.0 phr of at least one accelerator.

[0074] The tire flap obtained from the flap rubber composition described herein by way of examples reduces the rupture of the flap on the tube that causes tube failure. [0075] The flap of the present disclosure was tested in field and resulted with higher flap growth. No failure of tube was reported from the tire on field during service life. [0076] A tire having a flap, containing the flap rubber composition of the present disclosure, shows higher growth in the transverse direction when the tire is running. This is the key performance characteristic to eliminate the tire tube failure in the service life. It increases the life of a tire and also saves cost on changing the tire.

I/We Claim:
1. A flap rubber composition comprising:
a) 20 - 60 phr of at least one recycled rubber component;
b) 35 - 60 phr of styrene-butadiene rubber; c) 15 - 40 phr of at least one natural rubber component;

d) 20 - 45 phr of at least one secondary grade carbon black;
e) 1.0 - 1.6 phr of at least one crosslinking agent; and
f) 0.5 - 2.0 phr of at least one accelerator.
2. The flap rubber composition as claimed in claim 1, wherein the at least one
recycled rubber component is selected from the group consisting of the whole tire reclaim rubber, 80 mesh crumb rubber, and combinations thereof.
3. The flap rubber composition as claimed in claim 1, wherein the at least one
natural rubber component is selected from the group consisting of RSS3,
RSS4, TSR10, TSR20, and combinations thereof.
4. The flap rubber composition as claimed in claim 1, wherein the at least one
secondary grade carbon black has a surface area in the range of 77 - 87 mg/g
and is selected from the group consisting of N330, N358, N326, and
combinations thereof.
5. The flap rubber composition as claimed in claim 1, wherein the at least one
crosslinking agent is selected from sulphur, accelerators, and combinations
thereof.
6. The flap rubber composition as claimed in claim 1, wherein the at least one
accelerator is selected from the group consisting of 2-2'-
dithiobis(benzothiazole) (MBTS), N-oxydiethylene-2-benzothiazole
sulphonamide (MBS), tetramethylthiuram disulfide (TMTD), and
combinations thereof.

7. The flap rubber composition as claimed in claim 1, wherein the composition further comprises at least one primary grade carbon black having a concentration in a range of 5 - 30 phr.
8. The flap rubber composition as claimed in claim 7, wherein the at least one primary grade carbon black has a surface area in the range of 31 - 41 mg/g and is selected from the group consisting of N660, N630, N642, N650, N683, and combinations thereof.
9. The flap rubber composition as claimed in claim 1, wherein the flap rubber composition optionally comprises at least one additive selected from the group consisting of activator, processing aid, antioxidant, and combinations thereof.
10. The flap rubber composition as claimed in claim 9, wherein the activator has a concentration in a range of 2 - 4 phr, and is selected from the group consisting of zinc oxide, nano zinc oxide, zinc monomethacrylate, and combinations thereof; the processing aid has a concentration in a range of 1.0 - 20 phr, and is selected from the group consisting of steric acid, treated distillate aromatic extracted (TDAE) oil, aromatic oil, paraffinic oil, naphthenic oil, heavy naphthenic oil, residual aromatic extract (RAE), and combinations thereof; the antioxidant has a concentration in a range of 0.5 – 3.5 phr, and is selected from the group consisting of N-(1,3-dimethylbutyl)-N-phenyl-p-phenylenediamine (6PPD), wax, 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ), 1,2-dihydro-2,2,4-trimethylquinoline (TMDQ) N-isopropyl-N-phenyl-P-phenylenediamine (IPPD), and combinations thereof.
11. The flap rubber composition as claimed in any one of the claims 1-10, wherein the composition has a flap growth in a range of 12 - 15%.

12. The flap rubber composition as claimed in any one of the claims 1-10, wherein the composition has 300 % modulus in a range of 70 - 95 kg/cm2 at room temperature.
13. The flap rubber composition as claimed in any one of the claims 1-10, wherein the composition has a hardness in a range of 56 - 58 Shore A at room temperature.
14. A process of preparation of the flap rubber composition as claimed in claim 1, the process comprising:

a) contacting the at least one recycled rubber component, the styrene-butadiene rubber, the at least one natural rubber component, and the at least one secondary grade carbon black, to obtain a first mixture;
b) contacting the first mixture with the at least one crosslinking agent, and the at least one accelerator for a period in a range of 2 - 4 minutes carried out at a temperature in a range of 100°C - 110°C to obtain the second mixture; and
c) processing the second mixture to obtain the flap rubber composition.
15. A process of preparation of the flap rubber composition as claimed in any
one of the claims 1-14, the process comprising:
a) contacting the at least one recycled rubber component, the styrene-butadiene rubber, the at least one natural rubber component, the at least one secondary grade carbon black, the at least one primary grade carbon black, activator, processing aid, and antioxidant to obtain a third mixture;
b) contacting the third mixture with the at least one crosslinking agent, and the at least one accelerator for a period in a range of 2 - 4 minutes carried out at a temperature in a range of 100°C - 110°C to obtain the fourth mixture; and
c) processing the fourth mixture to obtain the flap rubber composition.

16. The process of preparation of the flap rubber composition as claimed in any
one of the claims 14 or 15, wherein processing the second mixture or the
fourth mixture to obtain the flap rubber composition comprises:
a) extruding the second mixture in an extruder for a period in a range of 110°C - 125°C to obtain an extruded product; and
b) curing the extruded product to obtain the flap rubber composition.

17. The process of preparation of the flap rubber composition as claimed in claim 16, wherein curing the extruded product to obtain the flap rubber composition is carried out at a temperature in a range of 160 - 180 °C for a period in a range of 2 - 5 minutes.
18. A tire having a flap fabricated using the flap rubber composition as claimed in any one of the claim 1-13.