DESC:FIELD OF THE INVENTION
The present invention relates to the field of tyre tread rubber composition. The present invention in particular relates to the tyre tread rubber composition with renewable filler and its method of preparation.

BACKGROUND OF THE INVENTION
Rubber is used as a raw material for the manufacture of over 40,000 products. Natural rubber possesses unique properties such as self-reinforcement, abrasion, tear, and impact resistance. These properties make natural rubber ideal for applications such as tires, conveyor belts, hoses, and gaskets.

Similarly, solution-based and emulsion-based styrene butadiene rubbers (SBR) and poly butadiene rubber (PBR) are used in tire components of rubber composition to provide its own unique properties like grip, low rolling resistance and wear property.

In any rubber compound, the polymer is the most expensive component. This has led to the use of the maximum possible loading of cheap minerals, biomaterials or petroleum-based fillers in polymeric products.
Most of the synthetic polymers and few other ingredients used in rubber composition are obtained from fossil based raw materials. Enormous effort is going on to produce products from fossil free biomaterials to contribute towards the conservation of global environment.

Fillers serve either as inexpensive diluents of the more expensive polymer phase or as reinforcing fillers to improve the physical properties of the rubber product. Diluent fillers must be especially low in cost to be of practical use. Historically, diluent fillers have been made from minerals of various kinds. Reinforcing fillers are expensive, can have high carbon footprints, and generally require a very small particle size (< 300 nm).

Mineral fillers are used in the rubber composition to increase the modulus of the final product and sometimes to improve tearing and abrasion resistance. As such, different fillers may be used when compounding either a natural or synthetic rubber to give the resulting rubber composite unique along with desired characteristics.

Polymer’s inherent properties are improved by the addition of reinforcing fillers such as carbon black and silica, which is derived from a non-renewable source, Carbon black is the oldest and most widely used and studied filler for rubber compounds. It is unique in its ability to enhance the properties of any base elastomer system, while at least moderately lowering overall rubber cost. This versatile reinforcing filler may be produced by the incomplete combustion of heavy petroleum products such as fluid catalytic cracking (FCC) tar, coal tar, and ethylene cracking tar. Due to concerns over global petroleum shortages, the cost of reinforcing carbon black is in increasing trend.

Use of biomaterials containing carbohydrates (starches, celluloses), proteins and lignin in tire rubber composition can contribute towards the conservation of global environment. Biomaterials are obtained from renewable sources and it is of low cost, abundant supply, environmental friendly and biodegradable. Several studies have been carried out on the incorporation of biomaterials filler in rubber compounds.

Reference made to the following:
Publication no. WO2015054685 relates to the use of rubber composition containing natural rubber component and a synthetic rubber component along with macro, micro or nano-sized fillers from vegetable waste filler comprises carbon fly ash, eggshell, guayule bagasse, tomato peel vegetable waste either as inexpensive diluents of the more expensive polymer phase or as reinforcing fillers to improve the physical properties of the rubber product whereas present invention discusses about the use of vegetable extract beet root powder as a filler to provide better reinforcement in tyre tread rubber composition.

Publication no. GB399277 relates to the use of residue obtained by extraction of vegetable fibre as a filler along with additional binder such as are gums, waxes, natural or synthetic resins, linseed oil, shellac, bitumen, asphalt whereas present invention discusses about the use of vegetable waste extract beetroot powder as a filler to have better reinforcement in tyre tread rubber composition.

Publication no. RO127830 relates to the use of regenerated rubber composition 90 to 100 parts of crumb rubber, 0-10 parts of textile waste, 2 to 6 parts of peptiser solution consisting of 70 to 80 % glycerin, 5 to 18 % mercapto compound, diphenylguanidine and other basic compounds soluble in glycerin, 2 to 25 % compatible peptiser and 5 to 20 parts of cameline seeds, cameline oil or cameline extraction residues used to devulcanize and regenerate the mixing components by thermochemical destruction method whereas present invention discusses about the use of vegetable waste extract beetroot powder as a filler to provide better reinforcement in tyre tread rubber composition. Both the cameline seeds and cameline oil and beetroot powder fillers are completely different from each other.

Publication no. JP2013526622 relates to the use of rubber composition containing SBR or BR, a thermoplastic elastomer vulcanized of EPDM and polypropylene (greater than 5 phr) along with silica and/or carbon black to have improved grip on the wet ground whereas present invention discusses about the use of vegetable waste extract beet root powder as a filler to have better reinforcement in tyre tread rubber composition.
Publication no. KR20130111811 relates to the use of environment-friendly process oil containing tire rubber composition containing raw rubber and silica & carbon black as reinforcing filler along with 1-25 parts of regenerated waste vegetable oil and at least one starch (vegetable/grain) so as to recycle vegetable waste easily and to have physical properties equal to or higher than that of a conventional tire rubber composition whereas present invention discusses about the use of vegetable waste extract beetroot powder as a filler to provide better reinforcement in tyre tread rubber composition.

Publication no. CN101906217 relates to the environment-friendly high-quality tyre reclaimed rubber manufacturing method by selecting waste radial tyre crowns having rubber composition containing rubber powder, vegetable pitch, odourless pine tar oil, starex, activating agent and water while blending whereas present invention discusses about the use of vegetable waste extract beetroot powder as a filler to have better reinforcement in tyre tread rubber composition.

Publication no. WO2009019684 relates to an effective and universal technological process which allows producing a wide variety of materials by the means of one equipment unit only. In this method of joint processing uses mineral oils, waste of hydrolysis of vegetable oils and/or animal fats as well as scrap automobile and/or other tires and/or other rubber waste whereas present invention discusses about the use of vegetable waste extract beetroot powder as a filler to have better reinforcement in tyre tread rubber composition.

Publication no. KR20140066293 relates to the use of rubber composition containing 100 parts by weight of a natural rubber and reclaimed rubber along with carbon black as a reinforcing filler and silica in a weight ratio of 50:20 to 40:30 and 5 to 20 parts by weight of a desulfurized regenerated rubber whereas present invention discusses about the use of vegetable waste extract beetroot powder as a filler to have better reinforcement in tyre tread rubber composition.

Publication no. KR100757889 relates to the use of tire tread rubber composition containing 100 parts of rubber along with cheap yellow soil and waste calcium triphosphate to improve dispersion and to lower manufacturing cost whereas present invention discusses about the use of vegetable waste extract beetroot powder as a filler to have better reinforcement in tyre tread rubber composition.

Publication no. JP2006306955 relates to the use of tire tread rubber composition containing 100 parts of rubber along with 0.5 parts of paper fibers to improvise both fuel economy and steering stability whereas present invention discusses about the use of vegetable waste extract beetroot powder as a filler to have better reinforcement in tyre tread rubber composition.
Thus, the filler derived from nonrenewable resources in particular carbon black has a considerable carbon footprint. Hence there is needed a renewable filler with a low or even zero carbon footprint for use in rubber compound which improves abrasion resistance of tyre treads.

In order to overcome above listed prior art, the present invention aims to provide a renewable filler for use in tyre tread rubber composition to improve abrasion resistance, better processing properties, elongation at grip, combination of wet and dry grip and combination of wet, lower rolling resistance and snow traction. The present invention provides tyre tread composition with renewable filler and its method of preparation.

OBJECTS OF THE INVENTION:
The principal object of the present invention is to provide tyre tread rubber composition with renewable filler and its method of preparation.

Yet another object of the present invention is a partial replacement or addition of renewable filler in tyre tread rubber composition.

Yet another object of the present invention is use of beetroot powder as renewable filler in tyre tread rubber composition.

Yet another object of the present invention is use of beetroot powder as renewable filler in SSBR: PBR blend based tyre tread rubber composition.

Yet another object of the present invention is to provide tyre tread rubber composition containing reinforcing filler carbon black and to replace silica with renewable filler beetroot powder is to provide wet grip, lower rolling resistance and snow traction.

Yet another object of the present invention is to provide tyre tread rubber composition containing a renewable filler along with reinforcing fillers carbon black and silica is to improve wet grip and dry grip.

Yet another object of the present invention is to provide tyre tread rubber composition is to provide better processing properties.

Another object of the present invention is to provide tyre tread rubber composition containing a renewable filler to provide better abrasion resistance.

SUMMARY OF THE INVENTION
One or more problems of the conventional prior arts are overcome by various embodiments of the present invention.

It is a primary aspect of the present invention to provide a tyre tread rubber composition using renewable filler, comprising of:
Polymer matrix– 100 phr;
reinforcing fillers– 40 -120 phr;
renewable filler – 5-20 phr;
Process Aid – 1 – 42 phr;
coupling agent – 0-3.5 phr;
activators – 2.5-7.5 phr;
anti-degradants – 1-4.5 phr;
vulcanization agent – 1-2.5 phr; and
primary accelerator – 1.5-2.5 phr;
wherein the beetroot powder is used as a renewable filler.

It is another aspect of the present invention to provide a tyre tread rubber composition using renewable filler, wherein polymer matrix is selected from SSBR and PBR and combinations thereof, preferably in a weight ratio of SSBR:PBR as 70-100: 30-0 phr.

It is another aspect of the present invention to provide a tyre tread rubber composition using renewable filler, wherein reinforcing filler is selected from carbon black, silica and combinations thereof, preferably carbon black 40-80 phr and silica 0-40 phr.

It is another aspect of the present invention to provide a tyre tread rubber composition using renewable filler, wherein coupling agent is selected from Si 75– 0-3.5 phr.

It is another aspect of the present invention to provide a tyre tread rubber composition using renewable filler, wherein the activators are selected from zinc oxide, stearic acid and combinations thereof, preferably zinc oxide – 2-4.5 phr and stearic acid- 1.5-3 phr.

It is another aspect of the present invention to provide a tyre tread rubber composition using renewable filler, wherein anti-degradants are selected from Microcrystalline wax (MC wax), N(1,3-dimethyl-butyl)-N’-phenylenediamine (6PPD) and combinations thereof, preferably MC wax- 0 – 2 phr and 6PPD – 1-2.5 phr.

It is another aspect of the present invention to provide a tyre tread rubber composition using renewable filler, wherein vulcanization agent is sulphur.

It is another aspect of the present invention to provide a tyre tread rubber composition using renewable filler, wherein primary accelerator is selected N- tert- butyl -2-benzothiazyl sulphenamide (TBBS).

It is another aspect of the present invention to provide a method for preparation of a tyre tread rubber composition using renewable filler as a beetroot powder, comprising of steps:
preparation of master batch in two stages:
First stage, rotating speed of the Banbury mixer between 55 to 60 rpm;
and the head temperature of the Banbury mixer maintained between 55°C to 65°C;
wherein polymers has been added in the mixing chamber and it has been allowed to mix for 0 to 50 seconds,
wherein further adding 100% of carbon black, silica, renewable filler beetroot powder coupling agent Si75, process aid MES oil and allowed to mix to the temperature ranges between 115°C to 130°C, and
wherein, process of silanization has been done with the reduced rotor speed of 20 to 30 rpm. The remaining rubber chemicals like stearic acid, mc wax (except zinc oxide and 6PPD) are added and allowed to mix in the time period 240 to 420 seconds and dumped at the temperature range of 130°C to 155°C and sheet out in two-roll mill.
Second stage as, Zinc oxide and 6PPD are added in stage I master batch and allowed to mix in the time period of 120 to 180 seconds at 70 rpm; and dumped at the temperature range of 125°C to 135°C, and sheet out in two-roll mill.

Preparation of final batch:
Cure chemicals primary accelerator TBBS and vulcanizing agent sulphur are added in Stage II master batch rubber compound and allowed to mix it in the time period of 120 to 240 seconds and dumped at the temperature range of 85°C to 110°C, and sheet out in two roll mill.

BRIEF DESCRIPTION OF DRAWINGS
Figure 1 illustrates Beetroot powder infrared spectrum obtained from FTIR (Fourier transform infrared spectroscopy), in accordance with an aspect of the present invention.

BRIEF DESCRIPTION OF THE INVENTION:
The present invention relates to tyre tread composition with renewable filler and its method of preparation. Beetroot powder containing betalain, phenolic components is used as a renewable filler along with reinforcing fillers carbon black and silica in tire tread rubber composition to improve abrasion resistance, wet grip and dry grip. Also, Beetroot powder is used as a reinforcing filler along with reinforcing filler carbon black and to replace reinforcing filler silica is to improve wet grip and LRR property.

The composition for tyre treads, comprises one or more rubbers; carbon black and silica as reinforcing fillers, a renewable filler beetroot powder; coupling agent; activators; anti-degradants; vulcanization agent; primary accelerator (Table 1 & 2). Thus, the renewable filler beetroot powder is able to provide better abrasion resistance whereas the other vegetable waste like vegetable waste filler comprises carbon fly ash, eggshell, guayule bagasse, tomato peel can provide better physical properties like tensile strength and Elongation at Break. Beetroot powder as a renewable filler in rubber composition to improve the abrasion resistance of rubber vulcanizate due to the presence of betalain and phenolic compounds.
The present invention relates to a tyre treads for a tyre and to rubber compositions according to Table 1 and Table 2 intended for the manufacture thereof. The rubber composition according to the invention comprises of:
a. The tyre tread composition acccording to the invention, which can be used for the manufacture of a tyre, comprising 100 parts by weight of a rubber(s), 75 parts by weight of a 37.5% oil extended solution styrene butadiene rubber with 25% of styrene content, 63% of vinyl content and Tg of -28°C. Also, another diene rubber used for the present invention is from the group consisting of the polybutadiene rubber, having greater tahan or equal to 96% high cis content.
b. Reinforcing filler, Carbon Black HAF (High Abrasion Furnace) ASTM grade N330, or any of the ASTM grades of Carbon Black having the Iodine adsorption No. 77 to 87 mg/gm, tinting strength value between 99 to 109 % ITRB, statistical thickness surface area value ranges between 70 to 80 m2/gm and with the blend of another reinforcing inorganic filler silica having nitrogen surface area value ranges from 170 to 190 m2/gm used for the present invention is to provide a tyre treads.
c. In order to couple the inorganic filler silica to the diene elastomer, bi functional organosilane coupling agent SI75 is used to provide a satisfactory bonding of chemical/or physical nature between the inorganic filler and diene elastomer(s).
d. In the present invention, Beet root powder used as a renewable filler used in the SSBR: PBR (75 phr :25 phr) blend based rubber composition is to provide a tyre tread having the essential characteristics abrasion resistance, combination of wet grip, LRR property and snow traction and combination of wet grip and dry grip. In FTIR image (Figure 1) the common peaks at 3327.54 cm-1, 1737.30 cm-1, 1627.14 cm-1, 1407.05 cm-1 corresponding to C-H stretching, C=O stretching, C=C stretching respectively were observed.
e. MES (Mild extracted solvate) oil is an environmentally friendly oil and is used to improve the processability of rubber compounds.
f. The other ingredients selected for the present invention is based on the conventional motorcycle tyre tread composition antidegradant 6PPD is added to the rubber composition to provide resistance to thermo-oxidative ageing of elastomers and MC Wax to protect against degradation by ozone.
g. Also, vulcanization activator zinc oxide and stearic acid are added to form zinc soap, improves the solubility of zinc oxide in the compound, and with the accelerator to form a complex, this complex reacts with sulphur to produce a strong cure activating system.
h. The vulcanization system used in the present invention is based on sulphur and on a primary accelerator TBBS.
Table 1: Rubber Composition in Phr
Ingredients Control rubber composition F1, Phr Formulation rubber composition related to invention
F2, Phr
SSBR 1 103.13 103.13
PBR 12202 25.00 25.00
N330 3 45.00 45.00
Beetroot powder 4 5.00
Silica 5 13.00 13.00
Si75 6 1.30 1.30
Zinc Oxide 7 2.75 2.75
Stearic Acid 8 1.75 1.75
MES Oil 9 4.00 4.00
MC Wax 10 1.75 1.75
6PPD 11 1.25 1.25
TBBS 12 2.10 2.10
Sulphur 13 2.10 2.10
Total, Phr 203.13 208.13

Table: 2 Rubber compositions in phr
Ingredients Control rubber composition F1, Phr Rubber composition related to invention
F3, Phr F4, Phr
SSBR 1 103.13 103.13 103.13
PBR 12202 25.00 25.00 25.00
Carbon Black N330 3 45.00 45.00 45.00
Beetroot powder 4 20.00 5.00
Precipitated Silica 5 13.00 13.00 8.00
Coupling agent Si75 6 1.30 1.30 0.80
Zinc Oxide 7 2.75 2.75 2.75
Stearic Acid 8 1.75 1.75 1.75
MES Oil 9 4.00 4.00 4.00
MC Wax 10 1.75 1.75 1.75
6PPD 11 1.25 1.25 1.25
TBBS 12 2.10 2.10 2.10
Sulphur 13 2.10 2.10 2.10
Total, Phr 203.13 223.13 202.63

1. SSBR– Solution styrene butadiene rubber (SOL C6270L) is 37.5 % oil extended SSBR having 25% of styrene content, 63% of vinyl content and Tg of -28°C.
2. PBR 1220 – High Cis Poly butadiene rubber from Reliance industries, India.
3. N330 – ASTM grade from Epsilon carbon, India.
4. Beetroot powder – It is a renewable filler from Mevive International Trading Company, M3 Mayflower metropolis, Udayampalayam road, sowripalayam, Coimbatore, Tamilnadu, India.
5. Precipitated Silica – It is a reinforcing inorganic filler from Tata chemicals limited, India.
6. SI75 – It is a coupling agent from Nanjing Shuguang Silane Chemical Co., Ltd, India.
7. Zinc oxide – It is from POCL enterprises limited, India.
8. Stearic acid- It is from 3F industries limited, India.
9. MES oil – It is mild extracted solvate oil from GP Petroleums limited, India.
10. MC Wax – It is microcrystalline wax is an antiozonant from Gujarat Paraffins private limited, India.
11. 6PPD N-(1, 3-Dimethylbutyl)-N’-phenyl-p-phenylenediamine is an antidegradant from Nocil Limited, India.
12. TBBS – It is N- tert- butyl -2-benzothiazyl sulphenamide delayed action accelerator from Nocil Limited, India.
13. Sulphur – It is a vulcanizing agent from Southern minerals and chemicals, India.

Method of preparation of a tyre tread rubber composition:
Mixing Sequence:
Using a Banbury mixer with a tangential rotor, a rubber composition prepared by a thermo- mechanical process is as follows:
Preparation of master batch:
Step I: Preparation of master batch has been performed with the rotation speed of the mixer between 55 to 60 rpm and with the head temperature of the Banbury maintained between 55°C to 65°C.
a) Mixing chamber has been charged with the selected rubbers and allowed to mix for 0 to 50 seconds.
b) Further by adding, 100 % of the reinforcing filler carbon black and 100% of the reinforcing filler silica, coupling agent Si75 and renewable filler as beetroot powder, process aid MES oil and allow it to mix up to the temperature ranges between 115°C to 130°C.
c) The process of silanization has been done with the reduced the rotor speed 20 to 30 rpm.
d) The remaining rubber chemicals like stearic acid, mc wax (except Zinc oxide and 6PPD are added) and allowed to mix in the time period of 240 to 420 seconds and dumped at the temperature range of 130°C to 155°C and sheeted out in the laboratory two-roll mill.
Step II: Mixing chamber of Banbury charged with the Step I master batch, Zinc oxide and 6PPD are added and allowed to mix in the time period of 120 to 180 seconds at 70 rpm and dumped at the temperature range of 125°C to 135°C. The rubber compound has been sheeted out in the laboratory two-roll mill.
Preparation of Final Batch: Mixing chamber has been charged with the Step II master batch and the curatives TBBS, primary accelerator and Sulphur, vulcanizing agent are allowed to mix in the time period of 120 to 240 seconds and dumped at the temperature range between 85°C to 110°C. Final sheet out has been done in the laboratory two-roll mill.
Results:
Characterization of Cured Rubber Vulcanizate and Uncured Rubber Compound:

Table 3: Properties of uncured Rubber Compound and Cured Rubber Vulcanizate
Properties F1, Control Rubber Composition F2, Rubber Composition related to invention Index
M1. Better Processability
Mooney Scorch @ 125°C
t5, minutes: minutes 70.65 51.88 -
M2. Physical properties
Tensile Strength, Mpa 14.63 15.59 106.56
Elongation at Break, % 454.90 529.13 16.32
M3. Din Abrasion Loss, mm3
Ideal value for SSBR: BR tyre tread rubber vulcanizate ranges from 140 mm3 to 290 mm 3 169.26 174.04 -

Table 4: Properties of uncured Rubber Compound and Cured Rubber Vulcanizate
Properties F1, Control Rubber composition F3, Rubber composition related to invention Index
M1. Better Processability
Mooney Scorch @ 125°C
t5, minutes: minutes
(Ideal t5 value of tread compound is greater than or equal to 18 minutes) 70.65 33.33 -
M4. Visco elastic properties of Rubber vulcanizate
Tan delta at 0 deg C 0.505 0.515 101.98
Tan delta at 25 deg C 0.221 0.247 111.76

Table 5: Properties of uncured Rubber Compound and Cured Rubber Vulcanizate
Properties F1, Control rubber composition F4, Rubber composition related to invention Index
M1. Better Processability
Mooney Scorch @ 125°C
t5, minutes: minutes
(Ideal t5 value of tread compound is greater than or equal to 18 minutes) 70.65 58.78 -
M4. Visco elastic properties of Rubber Vulcanizate
Tan delta at 0 deg C
(Higher the index value is better) 0.505 0.532 105.35
Tan delta at 60 deg C
(Lower the index value is better) 0.121 0.108 89.26

Complex modulus E* at -10 deg C
(Lower the index value is better) 35.06 32.09 91.53

Storage modulus E’ at -10 deg C, Mpa
(Lower the index value is better) 28.8 25.1 87.15

Whereas M determines the term measurement.
The compound properties are listed in Table 3, Table 4 & Table 5 as below:
The purpose of these tests is to measure the improved properties of the formulation related to the invention against control formulation. For this, SSBR: PBR blend based tyre tread rubber composition F2 reinforced by reinforcing fillers carbon black grade N330 and precipitated silica along with 5 phr of beetroot powder as a renewable filler are prepared against SSBR: BR blend based tyre tread rubber composition reinforced by fillers carbon black grade N330 and precipitated silica (F1 Control) is prepared and evaluated.

The purpose of these tests is to measure the improved properties of the formulation related to the invention against control formulation. For this, SSBR: PBR blend based tyre tread rubber composition F3 reinforced by reinforcing fillers carbon black grade N330 and precipitated silica along with 20 phr of beetroot powder as a renewable filler are prepared against SSBR: BR blend based tyre tread rubber composition reinforced by fillers carbon black grade N330 and precipitated silica (F1, Control) is prepared and evaluated.

The purpose of these tests is to measure the improved properties of the formulation related to the invention against control formulation. For this, SSBR: PBR blend based tyre tread rubber composition F4 reinforced by reinforcing fillers carbon black grade N330 and precipitated silica is replaced with 5 phr of beetroot powder as a renewable filler are prepared against SSBR: BR blend based tyre tread rubber composition reinforced by fillers carbon black grade N330 and precipitated silica (Control F1) is prepared and evaluated.

The present invention provides a tyre tread rubber compositions F2 and F3, SSBR: PBR blend reinforced by reinforcing fillers N330 carbon black and precipitated silica along with 5 phr & 20 phr of beetroot powder as a renewable filler gave t5 values 51.88 minutes and 33.33 minutes i.e., process safety (Note: Ideal value of tyre tread rubber compound is 18 minutes) when compared to SSBR: PBR blend based tyre tread rubber composition reinforced by reinforcing fillers N330 and precipitated silica (Control F1) gave t5 value is 70.65 minutes.

Also, the present invention provides a tyre tread rubber compositions F4, SSBR: PBR blend reinforced by reinforcing fillers N330 carbon black and precipitated silica is replaced with 5 phr of beetroot powder as a renewable filler gave t5 value 58.78 minutes i.e., process safety (Note: Ideal value of tyre tread rubber compound is 18 minutes) when compared to SSBR: PBR blend based tyre tread rubber composition reinforced by reinforcing fillers N330 and precipitated silica (Control F1) gave t5 value is 70.65 minutes.
The present invention provides a tyre tread rubber compositions F2, SSBR: PBR blend reinforced by reinforcing fillers N330 carbon black and precipitated silica along with 5 phr of beetroot powder as a renewable filler improved tensile strength by 6.56% and Elongation at break by 16.23% when compared to SSBR: PBR blend based tyre tread rubber composition reinforced by reinforcing fillers N330 and precipitated silica (Control F1).

The present invention provides a tyre tread rubber compositions F2, SSBR: PBR blend reinforced by reinforcing fillers N330 carbon black and precipitated silica along with 5 phr of beetroot powder as a renewable filler gave abrasion loss value is 174.04 mm3 (Note: Ideal din abrasion loss value for SSBR: BR blend based tread composition ranges from 140 mm3 to 290 mm3) when compared to SSBR: PBR blend based tyre tread rubber composition reinforced by reinforcing fillers N330 and precipitated silica gave din abrasion loss value is 169.26 mm3 (Control F1).

The present invention provides a tyre tread rubber compositions F3, SSBR: PBR blend reinforced by reinforcing fillers N330 carbon black and precipitated silica along with 20 phr of beetroot powder as a renewable filler improved wet grip 1.98% and dry grip by 11.76% when compared to SSBR: PBR blend based tyre tread rubber composition reinforced by reinforcing fillers N330 and precipitated silica (Control F1).

The present invention provides a tyre tread rubber compositions F4, SSBR: PBR blend reinforced by reinforcing fillers N330 carbon black and precipitated silica, precipitated silica is replaced with 5 phr of beetroot powder as a renewable filler improved wet grip by 5.35% and rolling resistance lowered by 11.76% when compared to SSBR: PBR blend based tyre tread rubber composition reinforced by reinforcing fillers N330 and precipitated silica (Control F1).

The present invention provides a tyre tread rubber compositions F4, SSBR: PBR blend reinforced by reinforcing fillers N330 carbon black and precipitated silica, precipitated silica is replaced with 5 phr of beetroot powder as a renewable filler complex modulus lowered by 8.47% and storage modulus lowered by 12.85 % when compared to SSBR: PBR blend based tyre tread rubber composition reinforced by reinforcing fillers N330 and precipitated silica (Control F1) and it exhibits snow traction (Lower the complex modulus and storage modulus improves the snow traction).

Hence, the present invention provides a tyre tread rubber composition reinforced by reinforcing fillers carbon black grade N330 and precipitated silica along with renewable filler beetroot powder provides optimum properties of abrasion resistance, physical properties like tensile strength, elongation at break and processing properties. Also, the present invention provides a tyre tread rubber composition reinforced by reinforcing fillers carbon black grade N330 and precipitated silica along with renewable filler beetroot powder provides combination of improved wet and dry grip and the tyre rubber composition is suitable for high performance tyre treads.
Moreover, a tyre tread rubber composition reinforced by reinforcing fillers carbon black grade N330 and precipitated silica replaced with renewable filler beetroot powder provides combination of improved wet grip, lower rolling resistance and snow traction.

Measurements and tests:
M1. Better processability (Process Requirements) of a Rubber Compound:
Mooney Scorch Characteristics (pre vulcanization characteristics using large rotor) for processability:
The Mooney Scorch measurements are carried out with a Mooney Viscometer (MV 2000 Alpha technologies, USA) according to ASTM D1646. t5 indicates the time to scorch (MV+5) which indicates the processing properties (process safety).
M2. Physical properties of Rubber Vulcanizate
Tensile properties of Rubber vulcanizate are carried out as per ASTM D 412 in universal testing machine, Instron Make Model 5966, USA.
M3. Din Abrasion Loss:
Din abrasion loss of the Rubber Vulcanizate is assessed in accordance with ASTM D 5963 using DIN Abrader from Prolific Engineers, India.
M4. Visco elastic properties of the rubber vulcanizate:
The dynamic properties or visco elastic properties of the rubber vulcanizate are measured in a dynamic mechanical analyzer (DMA Metravib +1000) with a dynamic strain 0.3%, static strain: 6% and temperature sweep ranges from -40 to +80°C, frequency: 10Hz in tension mode as per ASTM D5992.
Tan delta at 0°C is commonly used as a predictor of tyre wet grip. Also, higher the tan delta value at 0°C, better the wet grip.
Tan delta at 25°C is commonly used as a predictor for dry grip. Also, higher the tan delta value at 25°C, better the dry grip.
Complex modulus E* and Loss modulus E’ at -10 deg C is commonly used as a predictor for snow traction. Lower the value of E’ and E* better the snow traction.
,CLAIMS:I/We Claim:
1. A tyre tread rubber composition comprising:
Polymer matrix– 100 phr;
reinforcing fillers– 40-120 phr;
renewable filler– 5-20 phr;
coupling agent– 0-3.5 phr;
process aid – 1- 42 phr;
activators– 2.5-7.5 phr;
anti-degradants – 1-4.5 phr;
vulcanization agent– 1-2.5 phr; and
primary accelerator– 1.5-2.5 phr,
wherein the renewable filler is selected from beetroot powder.

2. The tire tread rubber composition as claimed in claim 1, wherein the polymer matrix is selected from SSBR and PBR and combinations thereof, preferably in a weight ratio of SSBR:PBR as ranging from 70-100: 30-0 phr.

3. The tire tread rubber composition as claimed in claim 1, wherein reinforcing filler is selected from carbon black, silica and combinations thereof, preferably carbon black ranging from 40-80 phr and silica ranging from 0-40 phr.

4. The tire tread rubber composition as claimed in claim 1, wherein coupling agent is selected from Si75 ranging from 0-3.5 phr.

5. The tire tread rubber composition as claimed in claim 1, wherein the activators are selected from zinc oxide, stearic acid and combinations thereof, preferably zinc oxide – 2-4.5 phr and stearic acid- 1.5-3.0 phr.

6. The tire tread rubber composition as claimed in claim 1, wherein the anti-degradants are selected from Microcrystalline wax (MC wax), N(1,3-dimethyl-butyl)-N’-phenylenediamine (6PPD) and combinations thereof, preferably MC wax- 0 – 2 phr and 6PPD – 1-2.5 phr.

7. The tire tread rubber composition as claimed in claim 1, wherein the vulcanization agent is sulphur.

8. The tire tread rubber composition as claimed in claim 1, wherein primary accelerator is selected N- tert- butyl -2-benzothiazyl sulphenamide (TBBS).

9. A method for preparation of tire tread rubber composition by way of renewable filler as a beetroot powder, comprising:
(i) maintaining Banbury mixer at a speed ranging from 55 to 60 rotations per minute (rpm) at head temperature of 55°C to 65°C;
(ii) adding polymers to the maintained Banbury mixer and allowing to mix for 1 to 50 seconds;
(iii) adding 100% of reinforcing fillers carbon black, silica, renewable filler beetroot powder, process aid MES oil, coupling agent Si75, to the temperature ranges between 115°C to 130°C;
(iv) reducing speed associated with the Banbury mixer to a range of 20 to 30 rpm;
(v) adding the remaining rubber chemicals such as stearic acid, mc wax and allowing to mix in a time period of 240 to 420 seconds and dumping at the temperature range of 130°C to 155°C, followed by sheeting the rubber compound in two roll mill, to obtain a first mixture (master batch);
(vi) first mixture (master batch) is added in the Banbury mixer followed by adding Zinc oxide and N(1,3-dimethyl-butyl)-N’-phenylenediamine (6PPD) for a time ranges from 120 to 180 seconds at 70 rpm;
(vii) dumping the rubber compound at a temperature range of 125°C to 135°C and followed by sheeting the rubber compound in two-roll mill, to obtain a second mixture (masterbatch);
(viii) second mixture (master batch) is added in Banbury Mixer followed by adding primary accelerator such as N- tert- butyl -2-benzothiazyl sulphenamide (TBBS) and vulcanizing agent such as sulphur and allowing to mix in a time period of 120 to 240 seconds; and
(ix) dumping the rubber compound at a temperature range of 85°C to 110°C and sheet out in two roll mill, to obtain a third mixture (Final batch).