Field of the Invention This invention relates to the development of hybrid carbon black grade comprising at least one carbon black, filler 1, and at least one nano structured carbon, graphene, filler 2, to improve the performance, such as, mechanical, dynamic mechanical, heat build up properties etc. of rubber compounds.

Background of the Invention Graphene, a crystalline, hexagonal close packed single atomic layer sp2 hybridized carbon material has attracted considerable attention recently in the field of rubber compounds for its space to improve rubber compound performances in applications such as, tire tread, tire carcass, tubes, shoe sole, hose, gasket, seal, and thermally and electrically conducting rubber articles etc. The performance of graphene in rubber depends on nature of graphene, retention of structural integrity of graphene and dispersion of graphene in rubber. Above all, high cost of graphene increases the final cost of the end products.

Carbon black, hard grades (designated as N100, N200, N300 series) and soft grades (designated as N500, N600, N700 series) are commonly used as cost effective filler for performance improvement and to achieve balanced properties in rubber, which disperse in the rubber comparatively easily than graphene.

A hybrid carbon black grade comprising graphene and carbon black can bring out the best performance/cost ratio of the end products produced by incorporating the hybrid carbon black grade in rubber with improved dispersion.

The Unites States patent application US2019/0040211 and PCT application W02017/029072 disclosed rubber compounds comprising graphene and one carbon black resulting improvement of modulus of rubber compounds. There exists immense scope of expanding rubber properties, such as, mechanical properties, dynamic mechanical properties, thermal properties, electrical conducting properties, thermal conducting properties by developing hybrid carbon black grade with graphene.

Objective of the Invention

The primary objective of the present invention is to prepare rubber compounds comprising a hybrid carbon black grade comprising at least one carbon black, filler 1, and at least one graphene, filler 2, and incorporation of the described hybrid carbon black grade in rubber to improve mechanical, dynamic mechanical, abrasion loss, and heat build up properties.

Another objective of the present invention is to prepare said hybrid carbon black grade comprising at least one carbon black, filler 1, with iodine adsorption number in the range of 25 to 166 mg/g, preferably in the range of 35 to 140 mg/g; nitrogen surface area (NSA) in the range of 19 m ² /g to 155 m ² /g, preferably in the range of 30 m ² /g to 131 m ² /g; oil absorption number (OAN) in the range of 65 ml/100 g to 140 ml/lOOg, more preferably in the range of 90 ml/lOOg to 127 ml/lOOg and graphene, filler 2.

Another objective of the present invention is to prepare said hybrid carbon black grade comprising graphene, filler 2, wherein the graphene is a single layered graphene or a multi layered graphene, or a mixture of single layered graphene and multi - layered graphene and/or aggregates of graphene.

Another objective of the present invention is to prepare said hybrid carbon black grade comprising graphene, filler 2, wherein said graphene is reduced graphene oxide (rGO).

In another objective of the invention is to prepare said rubber compounds comprising said hybrid carbon black grade showing improved mechanical, dynamic mechanical, abrasion loss and heat build up properties over rubber compounds comprising carbon black even with lower amount of hybrid carbon black grade.

Summary of the Invention The primary aspect of the present invention is directed to provide Rubber compound with improved mechanical, and dynamic mechanical property including a hybrid carbon black grade comprising :

(i) at least one carbon black, filler 1, having iodine adsorption number from about 25 mg/g to 166 mg/g; nitrogen surface area from about 19 m2/g to 155 m2/g; oil absorption number from about 65 ml/ 100 g to 140 ml/ 100 g ; and

(ii) at least one nano-structured carbon, rGO, filler 2, wherein the weight of filler 2 in hybrid carbon black grade is from 3 wt.% to 10 wt.% of said hybrid carbon black grade. Another aspect of the present invention is directed to provide said rubber wherein said hybrid carbon black grade comprising :

(a) at least one carbon black, filler 1, in amounts of 90 to 96.15. % by wt., wherein the iodine adsorption number ranges from about 25 mg/g to 166 mg/g, more preferably, ranges from about 35 mg/g to 140 mg/g; the nitrogen surface area ranges from about 19 m2/g to 155 m2/g, more preferably ranges from about 30 m2/g to 131 m2/g; and the oil absorption number ranges from about 65 ml/ 100 g to 140 ml/ 100 g; more preferably ranges from 90 ml/ 100 g to 127 ml/100 g.

(b) at least one nano-structured carbon filler, filler 2, graphene, more particularly, rGO in amounts of 3.85 to 10 % by wt., wherein, C/O ratio is at least about 5: 1, or at least about 15: 1, or at least about 20: 1, or at least about 50: 1, or at least about 75: 1 or at least 150: 1, or at least 250: 1, or at least 500: 1, or at least 750: 1; or at least 1000: 1; or at least 1500; 1; or at least 2000: 1; preferably in the range of about 250: 1 to about 500: 1, wherein the C/O ratio includes all value and sub-value between these ranges adapted for uniform dispersibility in rubber. Another aspect of the present invention is directed to provide said rubber compound comprising said nano-structured carbon, filler 2, selected from pristine graphene (PG), graphene nano platelet (GNP), graphene oxide (GO), reduced graphene oxide (rGO), e.g. thermally reduced graphene oxide (TrGO), chemically reduced graphene oxide (CrGO), preferably reduced graphene oxide (rGO).

Yet another aspect of the present invention is directed to provide said rubber compound, wherein said hybrid carbon black grade comprise hybrid carbon black in the form of pellets obtained from at least one carbon black, filler 1, and at least one nano-structured carbon, filler 2, rGO, and include binders including selected from molasses, sugar solution, sodium lignosulfonate, nano-cellulose, sodium la u ryl sulfate, sodium carboxymethyl cellulose, sodium carboxyethyl cellulose, poly(vinyl alcohol), poly(vinyl pyrollidone), poly(acryl amide) in the form of pellet, wherein the weight percentage of binder is 0 to 3 with respect to hybrid carbon black grade Or optionally water.

Another preferred aspect of the present invention is directed to provide said rubber compound comprising the total amount of hybrid carbon black grade in rubber ranges from 25 phr to 65 phr, more preferably ranges from 30 phr to 55 phr.

Another aspect of the present invention is directed to provide said rrubber compound, wherein said nano-structured carbon is selected from pristine graphene (PG), graphene nano platelet (GNP), graphene oxide (GO), reduced graphene oxide (rGO), e.g. thermally reduced graphene oxide (TrGO), chemically reduced graphene oxide (CrGO) and the improvement in mechanical properties attained include tensile strength up to 13 %, elongation at break up to 23 %, 100% modulus up to 89 %, 300% modulus up to 60 % and/or the improvement of dynamic mechanical property including, loss tangent up to 19%, storage modulus up to 83% and/or improvement of abrasion loss up to 8%, and/or improvement of heat build up property up to 19 %.

Another aspect of the present invention is directed to provide said rubber compound, wherein said nano-structured carbon comprises graphene comprising RGO, having the C/O ratio of at least about 5: 1, or at least about 15: 1, or at least about 20: 1, or at least about 50: 1, or at least about 75: 1 or at least 150: 1, or at least 250: 1, or at least 500: 1, or at least 750: 1; or at least 1000: 1; or at least 1500: 1; or at least 2000: 1; preferably in the range of about 250: 1 to about 500: 1, wherein the C/O ratio includes all value and sub-value between these ranges.

Yet another aspect of the present invention is directed to provide said rubber compound , wherein said hybrid carbon black grade is used in the form of pellets obtained from at least one carbon black, filler 1, and at least one nano- structured carbon, filler 2, rGO; and include binders selected from molasses, sugar solution, sodium lignosulfonate, nano-cellulose, sodium laurylsulfate, sodium carboxymethyl cellulose, sodium carboxyethyl cellulose, poly(vinyl alcohol), poly(vinyl pyrollidone), poly(acryl amide), wherein the weight percentage of binder is 0 to 3 with respect to hybrid carbon black grade.

Another aspect of the present invention is directed to provide said rubber compound, wherein said at least one carbon black, filler 1, is having the iodine adsorption number ranging from about 25 mg/g to 166 mg/g, more preferably, ranges from about 35 mg/g to 140 mg/g; the nitrogen surface area ranges from about 19 m2/g to 155 m2/g, more preferably ranges from about 30 m2/g to 131 m2/g; and the oil absorption number ranges from about 65 ml/100 g to 140 ml/ 100 g; more preferably ranges from 90 ml/ 100 g to 127 ml/ lOOg. Further aspect of the present invention is directed to provide said rubber compound, comprising natural rubber and hybrid carbon black grade 'HI', containing filler 1, N234 having Iodine adsorption number 121.5 mg/g; nitrogen surface area (NSA) 119.5 m ² /g; oil absorption number (OAN) 102 ml/100 g wherein, Ή contains 90 wt.% filler 1 and 10 wt.% filler 2, at a level of 30 phr of ΉI', enabling improvement of 100% modulus by 29%, elongation at break 11% and heat buildup by 15% respectively and lowering of loss tangent by about 13% with respect to the rubber compound comprising only N234 at a level of 45 phr.

Still further aspect of the present invention is directed to provide said rubber compound, comprising natural rubber and hybrid carbon black grade Ή containing filler 1, N234 having Iodine adsorption number 121.5 mg/g; nitrogen surface area (NSA) 119.5 m ² /g; oil absorption number (OAN) 102 ml/lOOg, wherein, Ή contains 90 wt.% filler 1 and 10 wt.% filler 2, at a level of 30 phr of ΉI'; enabling improvement of 100% modulus by 56%, 300% modulus by 18%, storage modulus by 12%, respectively and lowering of loss tangent by about 6%, heat build up by 8% and abrasion loss by 6% respectively with respect to the rubber compound comprising only N234 at a level of 40 phr. Another aspect of the present invention is directed to provide said rubber compound, comprising SBR-BR rubber compound and hybrid carbon black grade Ή containing filler 1, N234 having Iodine adsorption number 121.5 mg/g; nitrogen surface area (NSA) 119.5 m ² /g; oil absorption number (OAN) 102 ml/lOOg wherein, Ή contains 90 wt.% filler 1 and 10 wt.% filler 2, at a level of 30 phr of ΉI'; enabling improvement of loss tangent by 17%, heat buildup by 12% and comparable abrasion loss with respect to the rubber compound comprising only N234 at a level of 45 phr.

Yet another aspect of the present invention is directed to provide said rubber compound, comprising SBR-BR rubber compound and hybrid carbon black grade 'HI' containing 'filler 1, N234 having Iodine adsorption number 121.5 mg/g; nitrogen surface area (NSA) 119.5 m ² /g; oil absorption number (OAN) 102 ml/lOOg, wherein, Ή contains 90 wt.% filler 1 and 10 wt.% filler 2, at a level of 30 phr of Ή ; enabling improvement of loss tangent by 14%, heat build up by 7% and comparative abrasion loss with respect to the rubber compound comprising SBR- BR rubber compound and only N234 at a level of 40 phr.

Yet further aspect of the present invention is directed to provide said rubber compound, comprising natural rubber and hybrid carbon black grade Ή3' containing filler 1, N234 having Iodine adsorption number 121.5 mg/g; nitrogen surface area (NSA) 119.5 m ² /g; oil absorption number (OAN) 102 ml/lOOg, wherein Ή3' contains 93.75 wt.% filler 1 and 6.25 wt.% filler 2, at a level of 48 phr of Ή3'; enabling improvement of tensile strength by 13%, elongation at break and 100% modulus 12 % and 20% respectively, with consequent reduction of loss tangent, heat build up and abrasion loss by 9%, 19% and 8% respectively with respect to rubber compound comprising natural rubber compound and only N234 at a level of 60 phr.

Still another aspect of the present invention is directed to provide said rubber compound, comprising SBR-BR rubber and hybrid carbon black grade Ή3' containing 'filler 1, N234 having Iodine adsorption number 121.5 mg/g; nitrogen surface area (NSA) 119.5 m ² /g; oil absorption number (OAN) 102 ml/lOOg, wherein Ή3' contains 93.75 wt.% filler 1 and 6.25 wt.% filler 2, at a level of 48 phr of Ή3'; enabling improvement of 100% modulus by 21% and consequent reduction of loss tangent, heat build up and abrasion loss by 12%, 12% and 5% respectively with respect to rubber compound comprising SBR-BR rubber compound and only N234 at a level of 60 phr.

Another aspect of the present invention is directed to provide said rubber compound, comprising natural rubber and SBR_BR rubber respectively and hybrid carbon black grade Ή5' containing 'filler 1, N375 having iodine adsorption number, 92 mg/g; NSA 89 m2/g; oil absorption number 111 ml/lOOg), wherein Ή5' contains 93.75 wt.% filler 1 and 6.25 wt.% filler 2, at a level of 48 phr of Ή5'; enabling lowering of loss tangent 14% and 19%, heat buildup by 12% and 12% respectively and comparable abrasion loss with respect to rubber compound comprising natural rubber and SBR-BR rubber compound respectively and only N375 at a level of 60 phr. Yet another aspect of the present invention is directed to provide said rubber compound, comprising natural rubber and SBR_BR rubber respectively and hybrid carbon black grade Ή4' containing 'filler 1, N375 having iodine adsorption number, 92 mg/g; NSA 89 m2/g; oil absorption number 111 ml/lOOg), wherein Ή4' contains 96.15 wt.% filler 1 and 3.85 wt.% filler 2, at a level of 52 phr of Ή4';

Enabling lowering of loss tangent by 5% and 13%, heat build up by 7% and 6% respectively with respect to rubber compound comprising natural and SBR-BR rubber compound respectively and only N375 at a level of 60 phr. Further aspect of the present invention is directed to provide said rubber compound, comprising natural rubber and hybrid carbon black grade Ή6' containing 'filler 1, N660 having Iodine adsorption number 37 mg/g; nitrogen surface area (NSA) 35 m ² /g; oil absorption number (OAN) 91 ml/lOOg, wherein Ή6' contains 96.15 wt.% filler 1 and 3.85 wt.% filler 2, at a level of 52 phr of Ή6'; enabling improvement of tensile strength and elongation at break by 5.9% and 19%,; and 5.3% and 23% with respect to rubber compound comprising natural rubber compound and only N660 at a level of 70 and 60 phr respectively.

Still further aspect of the present invention is directed to provide said rubber compound, comprising natural rubber and hybrid carbon black grade Ή7' containing 'filler 1, N134 iodine adsorption number, 140 mg/g; NSA, 131 m2/g; oil absorption number (OAN), 127 ml/100 g, wherein, Ή7' contains 90 wt.% filler 1 and 10 wt.% filler 2, at a level of 30 phr of Ή7'; enabling improvement of 100% modulus by 61%, 300% modulus by 22% and storage modulus by 16% with consequent lowering of loss tangent by 12% and heat build up by 12% respectively with respect to rubber compound comprising natural rubber compound and only N134 at a level of 40 phr.

Still further aspect of the present invention is directed to provide said rubber compound, comprising SBR-BR rubber and hybrid carbon black grade Ή7' containing 'filler 1, N134 iodine adsorption number, 140 mg/g; NSA, 131 m2/g; oil absorption number (OAN), 127 ml/100 g, wherein, Ή7' contains 90 wt.% filler 1 and 10 wt.% filler 2, at a level of 30 phr of Ή7'; enabling improvement of 100% modulus by 15%, 300% modulus by 15% and storage modulus by 11% with simultaneous reduction of loss tangent by 12%, heat build up by 9% respectively with respect to rubber compound comprising SBR-BR rubber compound and only N134 at a level of 40 phr.

Further aspect of the present invention is directed to provide said rubber compounds incorporated in tyre tread, tyre side wall, tyre body component, wire and cable, hose, seal, gasket, engine mount, automotive components, electrically conducting rubber component, thermally conducting rubber component and the like.

Another aspect of the present invention is directed to provide a process for the preparation of said rubber compound including the step of providing said hybrid carbon black grade comprises the steps of providing selectively co-acting combination of

(i) at least one carbon black, filler 1, having iodine adsorption number from about 25 mg/g to 166 mg/g; nitrogen surface area from about 19 m2/g to 155 m2/g; oil absorption number from about 65 ml/ 100 g to 140 ml/ 100 g ; and

(ii) at least one nano-structured carbon, filler 2, wherein the weight of filler 2 in hybrid carbon black grade varying from 3.85 wt.% to 10 wt.% of said hybrid carbon black grade.

Yet Further aspect of the present invention is directed to provide said process further comprising subjecting the selective mix of said at least one carbon black, filler 1 and at least one nano-structured carbon, filler 2 to step of granulation or pelletization which is carried out either by addition of binders at a weight percentage of 1.5 to 3% with respect to hybrid carbon black with optional water addition or with only water without using binder employing granulator or pelletizer at a selected speed followed by drying.

Still further aspect of the present invention is directed to provide said process, wherein said binder includes molasses, sugar solution, sodium lignosulfonate, nano-cellulose, sodium lauryl sulfate, sodium carboxymethyl cellulose, sodium carboxyethyl cellulose, poly(vinyl alcohol), poly(vinyl pyrollidone), poly(acryl amide) preferably molasses at a concentration of 2 wt.% or less with respect to the hybrid carbon black grade. Another aspect of the present invention is directed to provide a process comprising selectively combining co-acting (i) hybrid carbon black grade comprising at least one carbon black, filler 1, and at least one nano-structured carbon, filler 2, wherein said nano-structured carbon, filler 2, is present in the carbon black grade about 3 wt.% to about 12 wt.% with respect to carbon black; and (ii) rubber wherein the total amount of hybrid carbon black grade in rubber ranges from 25 phr to 65 phr, more preferably ranges from 30 phr to 55 phr.

Another preferred aspect of the present invention is directed to provide said hybrid carbon black grade comprising:

(i) at least one carbon black, filler 1, having iodine adsorption number from about 25 mg/g to 166 mg/g; nitrogen surface area from about 19 m2/g to 155 m2/g; oil absorption number from about 65 ml/ 100 g to 140 ml/ 100 g ; and

(ii) At least one nano-structured carbon, rGO, filler 2, wherein the weight of filler 2 in hybrid carbon black grade is from 3 wt.% to 10 wt.% of said hybrid carbon black grade.

Still another aspect of the present invention is directed to provide said hybrid carbon black grade comprising : (a) at least one carbon black, filler 1, in amounts of 90 to 96.15. % by wt., wherein the iodine adsorption number ranges from about 25 mg/g to 166 mg/g, more preferably, ranges from about 35 mg/g to 140 mg/g; the nitrogen surface area ranges from about 19 m2/g to 155 m2/g, more preferably ranges from about 30 m2/g to 131 m2/g; and the oil absorption number ranges from about 65 ml/ 100 g to 140 ml/ 100 g; more preferably ranges from 90 ml/ 100 g to 127 ml/100 g.

(b) at least one nano-structured carbon filler, filler 2, graphene, more particularly, rGO in amounts of 3.85 to 10 % by wt., wherein, C/O ratio is at least about 5: 1, or at least about 15: 1, or at least about 20: 1, or at least about 50: 1, or at least about 75: 1 or at least 150: 1, or at least 250: 1, or at least 500: 1, or at least 750: 1; or at least 1000: 1; or at least 1500; 1; or at least 2000 : 1; preferably in the range of about 250: 1 to about 500: 1, wherein the C/O ratio includes all value and sub-value between these ranges adapted for uniform dispersibility in rubber.

Another aspect of the present invention is directed to provide said hybrid carbon black grade comprising said nano-structured carbon, filler 2, selected from pristine graphene (PG), graphene nano platelet (GNP), graphene oxide (GO), reduced graphene oxide (rGO), e.g. thermally reduced graphene oxide (TrGO), chemically reduced graphene oxide (CrGO), preferably reduced graphene oxide (rGO).

Yet another aspect of the present invention is directed to provide said hybrid carbon black grade, wherein said hybrid carbon black grade comprise hybrid carbon black in the form of pellets obtained from at least one carbon black, filler 1, and at least one nano-structured carbon, filler 2, rGO, and include binders including selected from molasses, sugar solution, sodium lignosulfonate, nano-cellulose, sodium la u ryl sulfate, sodium carboxymethyl cellulose, sodium carboxyethyl cellulose, poly(vinyl alcohol), poly(vinyl pyrollidone), poly(acryl amide) in the form of pellet, wherein the weight percentage of binder is upto 3 with respect to hybrid carbon black grade or optionally water. Still another aspect of the present invention is directed to provide the use of the hybrid carbon black grade in rubber compounds including selectively for manufacture of tyre tread, tyre side wall, tyre body component, wire and cable, hose, seal, gasket, engine mount, automotive components, electrically conducting rubber component, thermally conducting rubber component and so on. Detailed Description of the Invention

Carbon black is commonly used for reinforcement of rubber and to impart a balanced property in rubber. Reinforcement of rubber means enhancement of mechanical properties, preferably modulus. Carbon black is characterized by iodine adsorption number, NSA, OAN wherein, the iodine adsorption number and NSA indicate the particle size or surface area of carbon black and OAN represents the structure or free volume of carbon black. Smaller particle size of carbon black gives high surface area and high surface area carbon black possesses high iodine adsorption number and NSA; OAN indicate high structure or free volume of carbon black. Carbon black having high surface area, i.e. high iodine adsorption number or high NSA , such as, N110, N115, N121, N134, N219, N220, N231, N234, N299, N326, N330, N339, N347, N351, N375, when mixed with rubber provide high mechanical performance, high wear resistance, high hardness wherein, carbon black having low surface area, i.e. low iodine adsorption number or low NSA , such as, N550, N650, N660, N772, N774 when mixed with rubber provide comparatively low mechanical performance. High surface area carbon blacks need longer time to mix uniformly with rubber.

For the present invention, carbon black, filler 1, is selected from ASTM carbon black of N100 series (N134) or N200 series (N234), or N300 series (N375) or N500 series (N550) or N600 series (N660), or N700 series (N774). The iodine adsorption number of carbon black, filler 1, ranges from about 25 mg/g to 166 mg/g, more preferably, ranges from about 35 mg/g to 140 mg/g; the NSA ranges from about 19 m ² /g to 155 m ² /g, more preferably ranges from about 30 m ² /g to 131 m ² /g; and the OAN ranges from about 65 g/ml to 140 g/ml; more preferably ranges from 90 g/ml to 127 g/ml.

Various nano-structured carbon material, when mixed with rubber, enhance mechanical properties of the rubber compounds by manifolds in comparison to carbon black but at the expense of cost. The common nano-structured carbon material mixed with rubber are pristine graphene (PG), graphene nano platelet (GNP), graphene oxide (GO), reduced graphene oxide (rGO), e.g. thermally reduced graphene oxide (TrGO), chemically reduced graphene oxide (CrGO), single wall carbon nanotube (SWCNT), multi-wall carbon nanotube (MWCNT) and others.

Graphene is prepared by numerous methods, adopting mechanical and chemical exfoliation of graphite and the methods are well known in art. Alternatively, graphene can be prepared by the reaction of organic precursors such as methane and alcohols, e.g., by gas phase, plasma processes, and other methods known in the art. In this invention commercially available graphene is used.

The graphene can be a discrete separated particle and/or graphene can be an association of plurality of multilayered graphene, which is referred as aggregate of graphene. The PG may contain 1-5 layers of graphene and for GNP the number of layers may be 10 to 15.

GO refers to oxidized graphene containing epoxide, hydroxyl, and carboxyl groups etc. prepared by exfoliating graphite oxide or by oxidizing graphite, having the C/O ratio at least about 10: 1 to 2000: 1, wherein the C/O ratio varies depending on the method of oxidation employed. RGO's as used herein refers to the reduced product of graphene oxides. The graphene oxides can be either thermally reduced graphene oxide (TrGO) or chemically reduced graphene oxide (CrGO). The C/O ratio of rGO is higher than GO. The rGO can be judiciously used in rubber compounds to restore electrical conductivity and thermal conductivity and to achieve balanced improvement in mechanical properties. With a lower oxygen containing fraction rGO are more easily dispersed within non-polar rubber.

The surface area of graphene is a function of the number of graphene sheet stacked upon each other and calculated based on the number of stacked layers. The surface area of a monolayer PG without porosity is about 2700 m ² /g. The surface area of two layers of PG without porosity is about 1350 m ² /g. The BET surface area of the graphene may range between 60 m ² /g and 1500 m ² /g. Carbon black is used in rubber for reinforcement but addition of carbon black in rubber after a certain amount leads to lack of optimally balanced properties of rubber.

There are other carbon fillers, such as, carbon nanotube, graphene, which can improve the performance of rubber along with rubber reinforcement with comparatively less amount of addition. The final properties of rubber containing graphene are largely depend on the uniformity of dispersion of graphene in rubber and melt mixing of graphene alone in large quantity in rubber is challenging due to high viscosity of rubber during melt mixing causing non- uniform dispersion. Further, low packing density of graphene, tendency of graphene to form aggregate and comparatively inferior compatibility between graphene and rubber enhance melt mixing and dispersion challenges.

In order to select percent of graphene in rubber and to enhancement of performance to cost ratio of the end rubber products, a hybrid carbon black grade comprising graphene in carbon black may assist.

In one embodiment, this invention disclosed herein a hybrid carbon black grade comprising at least:

(a) one carbon black, filler 1, wherein the iodine adsorption number ranges from about 25 mg/g to 166 mg/g, more preferably, ranges from about 35 mg/g to 140 mg/g; the NSA ranges from about 19 m2/g to 155 m2/g, more preferably ranges from about 30 m2/g to 131 m2/g; and the OAN ranges from about 65 g/ml to 140 g/ml; more preferably ranges from 90 g/ml to 127 g/ml.

(b) one nano-structured carbon filler, filler 2, graphene, more particularly RGO, wherein, the C/O ratio is at least about 5: 1, or at least about 15: 1, or at least about 20: 1, or at least about 50: 1, or at least about 75: 1 or at least 150: 1, or at least 250: 1, or at least 500: 1, or at least 750: 1; or at least about 1000: 1, or at least about 1500: 1 or at least about 2000: 1; preferably in the range of about 250: 1 to about 500: 1, wherein the C/O ratio includes all value and sub-value between these ranges. In another embodiment, this invention disclosed herein, a hybrid carbon black grade comprising at least one carbon black, filler 1, and at least one nano- structured carbon, filler 2, rGO, wherein the nano-structured carbon, filler 2, is present in the carbon black grade about 3 wt% to about 12 wt% with respect to carbon black. The content, of filler 2, lower than 3 wt% in hybrid carbon black grade with respect to filler 1, results un-satisfactory level of improvement of properties of rubber, when mixed. The content of filler 2, higher than 12 wt% in hybrid carbon black grade with respect to filler 1, results non-uniform dispersion of hybrid carbon black grade in rubber, when mixed.

In one embodiment of this invention, the hybrid carbon black grade comprising at least one carbon black, filler 1, and at least one nano-structured carbon, filler 2, rGO is melt mixed with rubber.

In another embodiment, the total amount of hybrid carbon black grade in rubber ranges from 25 phr to 65 phr, more preferably ranges from 30 phr to 55 phr, wherein, phr means parts per hundred parts of rubber

In another embodiment of this invention, the properties of rubber containing 30 phr to 55 phr hybrid carbon black grade are compared with properties of rubber containing carbon black about 30 phr to about 80 phr, more preferably about 40 phr to about 70 phr.

In one embodiment, at least one exemplary carbon black includes ASTM 100 series, N134; ASTM 200 series, N234; ASTM 300 series, N375; ASTM 600 series, N660.

In one embodiment, the rubber includes natural rubber, styrene butadiene rubber, polybutadiene rubber, butyl rubber, bromobutyl rubber, chlorobutyl rubber, polyisoprene rubber, ethylene propylene rubber, ethylene propylene diene rubber, ethylene vinylacetate rubber, acrylic rubber, nitrile rubber, chlorosulfonated rubber, polyurethane rubber, polysulfide rubber, fluoro rubbers, polysiloxanes, functionalized rubbers of above mentioned rubbers, alone or their blends, more preferably the rubber includes natural rubber, styrene butadiene rubber, polybutadiene rubber alone or their blends. The rubber comprising hybrid carbon filler grade can further comprise additives selected from vulcanizing agent, 1 to 2 phr; accelerator, 1 to 2 phr; activator, 3 to 5 phr; retarder, 0 to 0.2 phr; anti-oxidant, 1 to 2 phr; anti-degradant, 1 to 2 phr; oil, 0-5 phr; processing aid, 2 to 3 phr; retarder, 0-0.2 phr; lubricant, 0-2 phr relative to the amount of the at least one rubber.

One embodiment of the invention describes the use of this rubber comprising hybrid carbon black grade, comprising at least one carbon black, filler 1, and at least one nano-structured carbon, filler 2, rGO, and additives described herein, can be used in the manufacture of different components of tyre, such as, tyre tread, tyre side wall, tyre body components. The use of this hybrid carbon black grade is not only limited to components of tyre, such as tyre tread, tyre side wall, tyre body component, the rubber comprising hybrid carbon black grade can be used in rubber article of electrical conductivity, thermal conductivity, wire and cable, battery cable, hoses, such as, turbo hoses, radiator hoses; seals, such as, transmission seals, fuel seals; gaskets, engine mount, vibration mount and automotive articles.

For the above-described applications, properties of rubber compound, such as, tensile strength, elongation at break, tear strength, modulus, storage modulus (E'), loss modulus (E "), loss tangent (tan delta), heat buildup, abrasion loss, hardness etc. are important parameters. The tan delta at 60 C is an indicator of rolling resistance of tyre, lower value of tan delta at 60 C indicates lower rolling resistance and favour fuel efficiency of automobiles. The ratio of loss modulus to storage modulus correspond to tan delta. Lowering of tan delta with higher storage modulus also desirable for tyre applications. Reduction of heat buildup (HBU) and abrasion loss increase durability of tyre.

Disclosed herein are methods of making the hybrid carbon black grade comprising at least one carbon black, filler 1, and at least one nano-structured carbon, filler 2, rGO. The hybrid carbon black grade can be made in the form of powder or in the form of pellet. The formation of pellet of carbon black is known as granulation or pelletization. The hybrid carbon black grade can be made from at least one carbon black, filler 1, and at least one nano-structured carbon, filler 2, rGO, by any conventional mixing methods known in the art, adopting dry or wet mixing of filler 1 and filler 2, followed by granulation or pelletization. During mixing of filler 1 and filler 2, binders, such as molasses, or sugar solution, or sodium lignosulfonate, or nano-cellulose, or sodium lauryl sulfate, or sodium carboxymethyl cellulose, or sodium carboxyethyl cellulose, or polyvinyl alcohol, or polyvinyl pyrollidone, or polyacryl amide is added to form the pellet.

The hybrid carbon black grade comprising filler 1 and filler 2 is prepared inside a drum shaped blender with the option of at least two entry locations for filler 1 and filler 2 to be used to prepare hybrid carbon black grade and one discharge location at the bottom of the blender followed by granulation. The options for attaching agitators, like paddles or ribbon are there inside the blender. However, to minimize breakage of carbon black pellets and structure of rGO due to intensive shear force with agitators, the hybrid carbon black grade is prepared under convection force preferably by 360° tumbling with sequential clockwise and anti-clockwise movement for a predetermined time period of 12 hours or less, 6 hours or less, or from about 5 minutes to about 6 hours or any other predetermined time in between at an rpm from about 100 to about 200, or from about 10 to 100. The other blenders, such as, 'V' blender, double cone blender, granulator and milling process can also be used for preparing the hybrid carbon black grade.

The hybrid carbon black grade and pellet from filler 1 and filler 2 can be made in a granulator comprising a principal rotor and a chopper capable of rotating at same or different rpm, wherein the rpm of the principal rotor is from about 100 to about 200, or from about 10 to 100 and the rpm of the chopper is about 50 to 150, or from about 5 to 100. The granulator described herein can be used as a mixer and pelletizer for a predetermined time of 12 hours or less, 6 hours or less, or from about 5 minutes to about 6 hours or any other predetermined time. The mixture of filler 1 and filler 2 produced in the blender described above can be feed in to the granulator for granulation or pelletization of carbon black grade.

The binders, such as molasses, or sugar solution, or sodium lignosulfonate, or nano-cellulose, or sodium lauryl sulfate, or sodium carboxymethyl cellulose, or sodium carboxyethyl cellulose, or polyvinyl alcohol, or polyvinyl pyrollidone, or polyacryl amide are added inside the blender or granulator with water, wherein the concentration of the binder with respect to hybrid carbon black grade is 3 wt% or less, more preferably 2 wt% or less. Granulation or pelletization of hybrid carbon black grade can be made using water only without use of binder.

The pellet of hybrid carbon black grade can also be made in process during manufacturing of carbon black by incorporating at least one nano-structured carbon, filler 2, rGO, inside the pelletizer of the manufacturing process along with carbon black in presence of water and/or a binder solution as disclosed above, followed by the drying process in a dryer.

Also described herein are the methods of making rubber compounds. The at least one rubber, at least one carbon black or hybrid carbon black grade are mixed by any conventional rubber melt mixing or compounding method.

In the melt mixing method, carbon blacks or hybrid carbon black grades are melt mixed at a predefined temperature of 150 C or less, 110 C or less, 90 C or less, 75 C or less, of from about 35 C to about 75 C with rubber along with different additives, such as processing aids, activators, anti-oxidants, anti-degradants and oil to prepare a masterbatch, where no vulcanizing agent is added. The rubber is initially masticated at a temperature in the range of 40 C to 110 C with processing aids followed by the addition of antioxidant and anti-degradants. Carbon blacks or hybrid carbon black grades are incorporated in the molten rubber as described above along with oil. The total mixing time of about 5 to 7 minutes is used.

The masterbatch produced by the method described above is then mixed with vulcanizing agent and accelerators by the conventional rubber mixing method at a temperature of 50 C or less, or from about 35 C to about 50 C to make final compounds. The melt mixing process can be performed either in open mill or in internal mixture or using both. The final compounds produced by the method described above are vulcanized in the temperature range of about 130 C to about 250 C under a pressure of 150 to 200 kg/cm ² .

Examples Preparation of Hybrid Carbon Black Grade

The hybrid carbon black grade of predefined composition is made by mixing at least one carbon black, filler 1, of iodine adsorption number from about 35 mg/g to 140 mg/g; NSA from about 30 m2/g to 131 m2/g; OAN from about 90ml/100 g to 127 ml/ 100 g and at least one nano-structured carbon, filler 2, rGO, wherein, the C/O ratio of rGO is about 500: 1, wherein the weight of filler 2, in hybrid carbon black grade varying from 3.85 wt% to 10 wt% of hybrid carbon black grade.

Carbon blacks, N134 (Iodine adsorption number 140 mg/g; NSA 131 m2/g; OAN 127 ml/100 g); N234 (Iodine adsorption number 121.5 mg/g; NSA 119.5 m ² /g; OAN 121 ml/lOOg), N375 (Iodine adsorption number 92 mg/g; NSA 89 m ² /g; OAN 111 ml/lOOg) and N660 (Iodine adsorption number 37 mg/g; NSA 35 m ² /g; OAN 91 ml/lOOg ) from Phillips Carbon Black Limited, India, are used to develop hybrid filler. Reduced Graphene Oxide (rGO) produced by thermal reduction of graphene oxide with characteristic weak XRD rGO peak at 25 degree two theta without any crystalline phase pattern is used for developing the hybrid filler. The rGO used has carbon content in the range of 95.8 wt% to 99.8 wt% analyzed by X-ray photo electron spectroscopy.

General method for Preparation of Hybrid Carbon Black Grades The hybrid carbon black grade comprising at least one carbon black, filler 1, and at least one nano-structured carbon, filler 2, rGO, are prepared in two stages. In the first stage, filler 1 and filler 2 are mixed inside a drum shaped blender containing a discharge location at the bottom of the blender. The filler 1 and filler 2 can be mixed in the blender for a time period of 15 to 30 minutes at an rpm of 75 to 100.

After the mixing of filler 1 and filler 2, the solid hybrid carbon black filler is discharged through the discharge location of the blender and conveyed to the granulator or pelletizer, where aqueous molasses solution is added at a weight percentage of 1.5 to 2 with respect to solid hybrid carbon black. Optionally, water is also added into the solid hybrid carbon black as required. The pellet of hybrid carbon black grade, is prepared in the granulator or pelletizer by selecting rotational speed of principal rotor, 50 to 200 rpm, and by selecting rotational speed of chopper, 25 to 100 rpm. The pellets of hybrid carbon black grade collected from granulator or pelletizer is then dried at a temperature of 150 C till dry.

The composition of hybrid carbon black grade, comprising carbon black, filler 1, (N234, N375, N660 and N134) and nano-structured carbon, filler 2, rGO, is shown in table 1.

Table 1: Composition of Hybrid Carbon Black Grade Preparation of Rubber Compounds Containing Carbon Black and Hybrid

Carbon Black Grade Mixing of rubber compound with CBs

The at least one rubber, at least one carbon black or hybrid carbon black grade are mixed by any conventional rubber melt mixing or compounding method.

In the melt mixing method, carbon blacks or hybrid carbon black grades are melt mixed for masterbatch at a predefined temperature of 150 C or less, 110 C or less, 90 C or less, 75 C or less, of from about 35 C to about 75 C with rubber along with different additives, such as processing aids, activators, anti-oxidants, anti-degradants and oil to prepare a masterbatch, where no vulcanizing agent is added. The rubber is initially masticated at a temperature in the range of 40 C to 110 C with processing aids followed by the addition of antioxidant and anti- degradants. Carbon blacks or hybrid carbon black grades are incorporated in the molten rubber as described above along with oil. The total mixing time of about 4 to 6 minutes is used.

Vulcanization The masterbatch produced by the method described above is then mixed with vulcanizing agent and accelerators by the conventional rubber mixing method at a temperature of 50 C or less, or from about 35 C to about 50 C to make final compounds. The compound produced is vulcanized at a temperature of 140-170 C for about 15 to about 35 minutes. Natural rubber (Ribbed Smoke Sheet, RSS1) of ML (1+4) 100 C of 50+- 5 from Indian Rubber Board, Kottayam, Kerala; polybutadiene (BR) rubber (BR, Reflex 1220 of 96% cis content from Reliance Industries Ltd., India); Oil extended (27.5 wt%) styrene butadiene rubber (SBR) containing 23.5 parts of styrene from Reliance Industries Ltd., India, are used for the present invention. The formulations of rubber compounds comprising carbon black and hybrid carbon black grade in natural rubber are shown in table 2.

Table 2 - Formulations of rubber compounds comprising carbon black and hybrid carbon black grade in natural rubber (components amount are indicated in parts per hundred parts of rubber, phr)

5

The formulations of rubber compounds comprising carbon black and hybrid carbon black grade in styrene butadiene and polybutadiene rubber blend (SBR- BR) are shown in table 3. Table 3 - Formulations of rubber compounds comprising carbon black and hybrid carbon black grade in SBR-BR blend (components amount are indicated in parts per hundred parts of rubber, phr)

5 Example 1 (El)

To prepare the rubber compound El, 100 g of natural rubber is masticated in a two roll mill at 35 C with 0.15 g of peptizer, and the following additives, 2.5 g of stearic acid, processing aids; 2 g of wax, lubricant; 5 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 2 g of 6PPD, anti-degradant are added. The mixture of natural rubber and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The hybrid carbon black grade, HI of 30 g. is then added gradually with addition of 4 g of aromatic oil, process aid and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.5 g of N-cyclohexyl-2- benzothiazole

Sulfenamide (CBS); 0.2 g of PVI, retarder are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 145 C for about 20 to about 25 minutes. This rubber compound is designated as El.

Example 2 (E2)

To prepare the rubber compound E2, 100 g of styrene butadiene rubber and polybutadiene rubber blend in the ratio of 70:30 is masticated in a two roll mill at 35 C and the following additives, 2.0 g of stearic acid, processing aids; 1.5 g of wax, lubricant; 3 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 1.2 g of 6PPD, anti-degradant are added. The mixture of styrene butadiene rubber and polybutadiene rubber blend and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The hybrid carbon black grade HI, of 30 g. is then added gradually and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.2 g of N- cyclohexyl-2- benzothiazole Sulfenamide (CBS); are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 160 C for about 20 to about 25 minutes. This rubber compound is designated as E2. Example 3 (E3)

To prepare the rubber compound E3, 100 g of natural rubber is masticated in a two roll mill at 35 C with 0.15 g of peptizer, and the following additives, 2.5 g of stearic acid, processing aids; 2 g of wax, lubricant; 5 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 2 g of 6PPD, anti-degradant are added. The mixture of natural rubber and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The hybrid carbon black grade, H2 of 52 g. is then added gradually with addition of 4 g of aromatic oil, process aid and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.5 g of N-cyclohexyl-2- benzothiazole Sulfenamide (CBS); 0.2 g of PVI, retarder are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 145 C for about 20 to about 25 minutes. This rubber compound is designated as E3.

Example 4 (E4)

To prepare the rubber compound E4, 100 g of natural rubber is masticated in a two roll mill at 35 C with 0.15 g of peptizer, and the following additives, 2.5 g of stearic acid, processing aids; 2 g of wax, lubricant; 5 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 2 g of 6PPD, anti-degradant are added. The mixture of natural rubber and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The hybrid carbon black grade, H3 of 48 g. is then added gradually with addition of 4 g of aromatic oil, process aid and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.5 g of N-cyclohexyl-2- benzothiazole Sulfenamide (CBS); 0.2 g of PVI, retarder are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound. The compound produced is vulcanized at a temperature of 145 C for about 20 to about 25 minutes. This rubber compound is designated as E4.

Example 5 (E5)

To prepare the rubber compound E5, 100 g of styrene butadiene rubber and polybutadiene rubber blend in the ratio of 70:30 is masticated in a two roll mill at 35 C and the following additives, 2.0 g of stearic acid, processing aids; 1.5 g of wax, lubricant; 3 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 1.2 g of 6PPD, anti-degradant are added. The mixture of styrene butadiene rubber and polybutadiene rubber blend and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The hybrid carbon black grade H2, of 52 g. is then added gradually and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.2 g of N- cyclohexyl-2- benzothiazole Sulfenamide (CBS); are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound. The compound produced is vulcanized at a temperature of 160 C for about 20 to about 25 minutes. This rubber compound is designated as E5.

Example 6 (E6)

To prepare the rubber compound E6, 100 g of styrene butadiene rubber and polybutadiene rubber blend in the ratio of 70:30 is masticated in a two roll mill at 35 C and the following additives, 2.0 g of stearic acid, processing aids; 1.5 g of wax, lubricant; 3 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 1.2 g of 6PPD, anti-degradant are added. The mixture of styrene butadiene rubber and polybutadiene rubber blend and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The hybrid carbon black grade H3, of 48 g. is then added gradually and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.2 g of N- cyclohexyl-2- benzothiazole Sulfenamide (CBS); are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound. The compound produced is vulcanized at a temperature of 160 C for about 20 to about 25 minutes. This rubber compound is designated as E6.

Example 7 (E7) To prepare the rubber compound E7, 100 g of natural rubber is masticated in a two roll mill at 35 C with 0.15 g of peptizer, and the following additives, 2.5 g of stearic acid, processing aids; 2 g of wax, lubricant; 5 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 2 g of 6PPD, anti-degradant are added. The mixture of natural rubber and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The hybrid carbon black grade, H4 of 52 g. is then added gradually with addition of 4 g of aromatic oil, process aid and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.5 g of N-cyclohexyl-2- benzothiazole Sulfenamide (CBS); 0.2 g of PVI, retarder are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 145 C for about 20 to about 25 minutes. This rubber compound is designated as E7.

Example 8 (E8) To prepare the rubber compound E8, 100 g of natural rubber is masticated in a two roll mill at 35 C with 0.15 g of peptizer, and the following additives, 2.5 g of stearic acid, processing aids; 2 g of wax, lubricant; 5 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 2 g of 6PPD, anti-degradant are added. The mixture of natural rubber and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The hybrid carbon black grade, H5 of 48 g. is then added gradually with addition of 4 g of aromatic oil, process aid and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.5 g of N-cyclohexyl-2- benzothiazole Sulfenamide (CBS); 0.2 g of PVI, retarder are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 145 C for about 20 to about 25 minutes. This rubber compound is designated as E8. Example 9 (E9)

To prepare the rubber compound E9, 100 g of styrene butadiene rubber and polybutadiene rubber blend in the ratio of 70:30 is masticated in a two roll mill at 35 C and the following additives, 2.0 g of stearic acid, processing aids; 1.5 g of wax, lubricant; 3 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 1.2 g of 6PPD, anti-degradant are added. The mixture of styrene butadiene rubber and polybutadiene rubber blend and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The hybrid carbon black grade H4, of 52 g. is then added gradually and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.2 g of INI- cyclohexyl-2- benzothiazole Sulfenamide (CBS); are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 160 C for about 20 to about 25 minutes. This rubber compound is designated as E9.

Example 10 (EIO) To prepare the rubber compound EIO, 100 g of styrene butadiene rubber and polybutadiene rubber blend in the ratio of 70:30 is masticated in a two roll mill at 35 C and the following additives, 2.0 g of stearic acid, processing aids; 1.5 g of wax, lubricant; 3 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 1.2 g of 6PPD, anti-degradant are added. The mixture of styrene butadiene rubber and polybutadiene rubber blend and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The hybrid carbon black grade H5, of 48 g. is then added gradually and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.2 g of N- cyclohexyl-2- benzothiazole Sulfenamide (CBS); are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 160 C for about 20 to about 25 minutes. This rubber compound is designated as E10.

Example 11 (Ell)

To prepare the rubber compound Ell, 100 g of natural rubber is masticated in a two roll mill at 35 C with 0.15 g of peptizer, and the following additives, 2.5 g of stearic acid, processing aids; 2 g of wax, lubricant; 5 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 2 g of 6PPD, anti-degradant are added. The mixture of natural rubber and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The hybrid carbon black grade, H6 of 52 g. is then added gradually with addition of 4 g of aromatic oil, process aid and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.5 g of N-cyclohexyl-2- benzothiazole Sulfenamide (CBS); 0.2 g of PVI, retarder are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 145 C for about 20 to about 25 minutes. This rubber compound is designated as Ell. Example 12 (E12)

To prepare the rubber compound E12, 100 g of natural rubber is masticated in a two roll mill at 35 C with 0.15 g of peptizer, and the following additives, 2.5 g of stearic acid, processing aids; 2 g of wax, lubricant; 5 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 2 g of 6PPD, anti-degradant are added. The mixture of natural rubber and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The hybrid carbon black grade, H7 of 30 g. is then added gradually with addition of 4 g of aromatic oil, process aid and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.5 g of N-cyclohexyl-2- benzothiazole Sulfenamide (CBS); 0.2 g of PVI, retarder are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 145 C for about 20 to about 25 minutes. This rubber compound is designated as E12.

Example 13 (E13)

To prepare the rubber compound E13, 100 g of styrene butadiene rubber and polybutadiene rubber blend in the ratio of 70:30 is masticated in a two roll mill at 35 C and the following additives, 2.0 g of stearic acid, processing aids; 1.5 g of wax, lubricant; 3 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 1.2 g of 6PPD, anti-degradant are added. The mixture of styrene butadiene rubber and polybutadiene rubber blend and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The hybrid carbon black grade H7, of 30 g. is then added gradually and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.2 g of N- cyclohexyl-2- benzothiazole Sulfenamide (CBS); are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 160 C for about 20 to about 25 minutes. This rubber compound is designated as E13. Example 14 (E14)

To prepare the rubber compound E14, 100 g of styrene butadiene rubber and polybutadiene rubber blend in the ratio of 70:30 is masticated in a two roll mill at 35 C and the following additives, 2.0 g of stearic acid, processing aids; 1.5 g of wax, lubricant; 3 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 1.2 g of 6PPD, anti-degradant are added. The mixture of styrene butadiene rubber and polybutadiene rubber blend and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The hybrid carbon black grade Ή8', of 60 g. is then added gradually and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.2 g of N-cyclohexyl-2- benzothiazole Sulfenamide (CBS) are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 160 C for about 20 to about 25 minutes. This rubber compound is designated as Έ14'. Example 15 (E15)

To prepare the rubber compound E15, 100 g of styrene butadiene rubber and polybutadiene rubber blend in the ratio of 70:30 is masticated in a two roll mill at 35 C and the following additives, 2.0 g of stearic acid, processing aids; 1.5 g of wax, lubricant; 3 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 1.2 g of 6PPD, anti-degradant are added. The mixture of styrene butadiene rubber and polybutadiene rubber blend and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The hybrid carbon black grade Ή9', of 60 g. is then added gradually and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.2 g of N-cyclohexyl-2- benzothiazole Sulfenamide (CBS); are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 160 C for about 20 to about 25 minutes. This rubber compound is designated as Έ15'. Example 16 (E16)

To prepare the rubber compound E16, 100 g of styrene butadiene rubber and polybutadiene rubber blend in the ratio of 70:30 is masticated in a two roll mill at 35 C and the following additives, 2.0 g of stearic acid, processing aids; 1.5 g of wax, lubricant; 3 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 1.2 g of 6PPD, anti-degradant are added. The mixture of styrene butadiene rubber and polybutadiene rubber blend and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The hybrid carbon black grade 'HIO', of 60 g. is then added gradually and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.2 g of N-cyclohexyl-2- benzothiazole Sulfenamide (CBS); are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 160 C for about 20 to about 25 minutes. This rubber compound is designated as Έ16'.

Comparative Example 1 (CE1)

To prepare the rubber compound CE1, 100 g of natural rubber is masticated in a two-roll mill at 35 C with 0.15 g of peptizer, and the following additives, 2.5 g of stearic acid, processing aids; 2 g of wax, lubricant; 5 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 2 g of 6PPD, anti-degradant are added. The mixture of natural rubber and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The carbon black N234 of 45 g. is then added gradually with addition of 4 g of aromatic oil, process aid and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.5 g of N-cyclohexyl-2- benzothiazole Sulfenamide (CBS); 0.2 g of PVI, retarder are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 145 C for about 20 to about 25 minutes. This rubber compound is designated as CE1. Comparative Example 2 (CE2)

To prepare the rubber compound CE2, 100 g of natural rubber is masticated in a two roll mill at 35 C with 0.15 g of peptizer, and the following additives, 2.5 g of stearic acid, processing aids; 2 g of wax, lubricant; 5 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 2 g of 6PPD, anti-degradant are added. The mixture of natural rubber and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The carbon black N234 of 40 g. is then added gradually with addition of 4 g of aromatic oil, process aid and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.5 g of N-cyclohexyl-2- benzothiazole Sulfenamide (CBS); 0.2 g of PVI, retarder are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 145 C for about 20 to about 25 minutes. This rubber compound is designated as CE2.

Comparative Example 3 (CE3)

To prepare the rubber compound CE3, 100 g of natural rubber is masticated in a two-roll mill at 35 C with 0.15 g of peptizer, and the following additives, 2.5 g of stearic acid, processing aids; 2 g of wax, lubricant; 5 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 2 g of 6PPD, anti-degradant are added. The mixture of natural rubber and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The carbon black N234 of 35 g. is then added gradually with addition of 4 g of aromatic oil, process aid and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.5 g of N-cyclohexyl-2- benzothiazole Sulfenamide (CBS); 0.2 g of PVI, retarder are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 145 C for about 20 to about 25 minutes. This rubber compound is designated as CE3. Comparative Example 4 (CE4)

To prepare the rubber compound CE4, 100 g of natural rubber is masticated in a two roll mill at 35 C with 0.15 g of peptizer, and the following additives, 2.5 g of stearic acid, processing aids; 2 g of wax, lubricant; 5 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 2 g of 6PPD, anti-degradant are added. The mixture of natural rubber and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The carbon black N234 of 30 g. is then added gradually with addition of 4 g of aromatic oil, process aid and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.5 g of N-cyclohexyl-2- benzothiazole Sulfenamide (CBS); 0.2 g of PVI, retarder are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 145 C for about 20 to about 25 minutes. This rubber compound is designated as CE4.

Comparative Example 5 (CE5)

To prepare the rubber compound CE5, 100 g of styrene butadiene rubber and polybutadiene rubber blend in the ratio of 70:30 is masticated in a two roll mill at 35 C and the following additives, 2.0 g of stearic acid, processing aids; 1.5 g of wax, lubricant; 3 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 1.2 g of 6PPD, anti-degradant are added. The mixture of styrene butadiene rubber and polybutadiene rubber blend and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The carbon black N234 of 45 g. is then added gradually and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.2 g of N- cyclohexyl-2- benzothiazole Sulfenamide (CBS); are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 160 C for about 20 to about 25 minutes. This rubber compound is designated as CE5. Comparative Example 6 (CE6)

To prepare the rubber compound CE5, 100 g of styrene butadiene rubber and polybutadiene rubber blend in the ratio of 70:30 is masticated in a two roll mill at 35 C and the following additives, 2.0 g of stearic acid, processing aids; 1.5 g of wax, lubricant; 3 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 1.2 g of 6PPD, anti-degradant are added. The mixture of styrene butadiene rubber and polybutadiene rubber blend and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The carbon black N234 of 40 g. is then added gradually and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.2 g of N- cyclohexyl-2- benzothiazole Sulfenamide (CBS); are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 160 C for about 20 to about 25 minutes. This rubber compound is designated as CE6.

Comparative Example 7 (CE7)

To prepare the rubber compound CE7, 100 g of styrene butadiene rubber and polybutadiene rubber blend in the ratio of 70:30 is masticated in a two roll mill at 35 C and the following additives, 2.0 g of stearic acid, processing aids; 1.5 g of wax, lubricant; 3 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 1.2 g of 6PPD, anti-degradant are added. The mixture of styrene butadiene rubber and polybutadiene rubber blend and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The carbon black N234 of 35 g. is then added gradually and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.2 g of N- cyclohexyl-2- benzothiazole Sulfenamide (CBS); are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 160 C for about 20 to about 25 minutes. This rubber compound is designated as CE7.

Comparative Example 8 (CE8)

To prepare the rubber compound CE8, 100 g of styrene butadiene rubber and polybutadiene rubber blend in the ratio of 70:30 is masticated in a two roll mill at 35 C and the following additives, 2.0 g of stearic acid, processing aids; 1.5 g of wax, lubricant; 3 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 1.2 g of 6PPD, anti-degradant are added. The mixture of styrene butadiene rubber and polybutadiene rubber blend and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The carbon black N234 of 30 g. is then added gradually and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.2 g of N- cyclohexyl-2- benzothiazole Sulfenamide (CBS); are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound. The compound produced is vulcanized at a temperature of 160 C for about 20 to about 25 minutes. This rubber compound is designated as CE8.

Comparative Example 9 (CE9)

To prepare the rubber compound CE9, 100 g of natural rubber is masticated in a two roll mill at 35 C with 0.15 g of peptizer, and the following additives, 2.5 g of stearic acid, processing aids; 2 g of wax, lubricant; 5 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 2 g of 6PPD, anti-degradant are added. The mixture of natural rubber and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The carbon black N234 of 60 g. is then added gradually with addition of 4 g of aromatic oil, process aid and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.5 g of N-cyclohexyl-2- benzothiazole Sulfenamide (CBS); 0.2 g of PVI, retarder are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound. The compound produced is vulcanized at a temperature of 145 C for about 20 to about 25 minutes. This rubber compound is designated as CE9.

Comparative Example 10 (CEIO)

To prepare the rubber compound CEIO, 100 g of styrene butadiene rubber and polybutadiene rubber blend in the ratio of 70:30 is masticated in a two roll mill at 35 C and the following additives, 2.0 g of stearic acid, processing aids; 1.5 g of wax, lubricant; 3 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 1.2 g of 6PPD, anti-degradant are added. The mixture of styrene butadiene rubber and polybutadiene rubber blend and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The carbon black N234 of 60 g. is then added gradually and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.2 g of N- cyclohexyl-2- benzothiazole Sulfenamide (CBS); are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 160 C for about 20 to about 25 minutes. This rubber compound is designated as CE10.

Comparative Example 11 (CE11) To prepare the rubber compound CE11, 100 g of natural rubber is masticated in a two roll mill at 35 C with 0.15 g of peptizer, and the following additives, 2.5 g of stearic acid, processing aids; 2 g of wax, lubricant; 5 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 2 g of 6PPD, anti-degradant are added. The mixture of natural rubber and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The carbon black N375 of 60 g. is then added gradually with addition of 4 g of aromatic oil, process aid and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.5 g of N-cyclohexyl-2- benzothiazole Sulfenamide (CBS); 0.2 g of PVI, retarder are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 145 C for about 20 to about 25 minutes. This rubber compound is designated as CE11.

Comparative Example 12 (CE12)

To prepare the rubber compound CE12, 100 g of styrene butadiene rubber and polybutadiene rubber blend in the ratio of 70:30 is masticated in a two roll mill at 35 C and the following additives, 2.0 g of stearic acid, processing aids; 1.5 g of wax, lubricant; 3 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 1.2 g of 6PPD, anti-degradant are added. The mixture of styrene butadiene rubber and polybutadiene rubber blend and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The carbon black N375 of 60 g. is then added gradually and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.2 g of N- cyclohexyl-2- benzothiazole Sulfenamide (CBS); are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 160 C for about 20 to about 25 minutes. This rubber compound is designated as CE12.

Comparative Example 13 (CE13) To prepare the rubber compound CE13, 100 g of natural rubber is masticated in a two roll mill at 35 C with 0.15 g of peptizer, and the following additives, 2.5 g of stearic acid, processing aids; 2 g of wax, lubricant; 5 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 2 g of 6PPD, anti-degradant are added. The mixture of natural rubber and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The carbon black N660 of 70 g. is then added gradually with addition of 4 g of aromatic oil, process aid and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.5 g of N-cyclohexyl-2- benzothiazole Sulfenamide (CBS); 0.2 g of PVI, retarder are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 145 C for about 20 to about 25 minutes. This rubber compound is designated as CE13.

Comparative Example 14 (CE14) To prepare the rubber compound CE14, 100 g of natural rubber is masticated in a two roll mill at 35 C with 0.15 g of peptizer, and the following additives, 2.5 g of stearic acid, processing aids; 2 g of wax, lubricant; 5 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 2 g of 6PPD, anti-degradant are added. The mixture of natural rubber and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The carbon black N660 of 60 g. is then added gradually with addition of 4 g of aromatic oil, process aid and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.5 g of N-cyclohexyl-2- benzothiazole Sulfenamide (CBS); 0.2 g of PVI, retarder are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 145 C for about 20 to about 25 minutes. This rubber compound is designated as CE14.

Comparative Example 15 (CE15)

To prepare the rubber compound CE15, 100 g of natural rubber is masticated in a two roll mill at 35 C with 0.15 g of peptizer, and the following additives, 2.5 g of stearic acid, processing aids; 2 g of wax, lubricant; 5 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 2 g of 6PPD, anti-degradant are added. The mixture of natural rubber and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The carbon black N134 of 40 g. is then added gradually with addition of 4 g of aromatic oil, process aid and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.5 g of N-cyclohexyl-2- benzothiazole Sulfenamide (CBS); 0.2 g of PVI, retarder are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 145 C for about 20 to about 25 minutes. This rubber compound is designated as CE15. Comparative Example 16 (CE16)

To prepare the rubber compound CE16, 100 g of styrene butadiene rubber and polybutadiene rubber blend in the ratio of 70:30 is masticated in a two roll mill at 35 C and the following additives, 2.0 g of stearic acid, processing aids; 1.5 g of wax, lubricant; 3 g of zinc oxide, activator; 1 g of trimethoxy quinoline (TMQ), anti-oxidant; 1.2 g of 6PPD, anti-degradant are added. The mixture of styrene butadiene rubber and polybutadiene rubber blend and the disclosed additives are mixed in two roll mill for 2 to 3 minutes. The carbon black N134 of 40 g. is then added gradually and mixed for another 4 to 5 minutes, which produce the masterbatch. The vulcanizing agents, such as 1.5 g of sulfur; 1.2 g of N- cyclohexyl-2- benzothiazole Sulfenamide (CBS); are mixed with masterbatch for 1 to 2 minutes in the two roll mill to produce final compound.

The compound produced is vulcanized at a temperature of 160 C for about 20 to about 25 minutes. This rubber compound is designated as CE16.

Results and Discussion

The mechanical, dynamic mechanical, heat build up, abrasion loss of natural rubber compounds comprising hybrid carbon black grade, such as, El, E3, E4, E7, E8, Ell, E12 are shown in table 4. The properties of corresponding natural rubber compounds comprising ASTM grade carbon black, such as, N134, N234, N375 and N660, CE1, CE2, CE3, CE4, CE9, CE11, CE13, CE14, and CE15 are also shown in table 4.

The mechanical, dynamic mechanical, heat build up, abrasion loss of SBR-BR blend compounds comprising hybrid carbon black grade, such as, E2, E5, E6, E9, E10, E13, are shown in table 5. The properties of corresponding SBR-BR compounds comprising ASTM grade carbon black, such as, N134, N234, and N375; CE5, CE6, CE7, CE8, CE10, CE12, CE16, are also shown in table 5.

Table 4: Properties of Natural Rubber Compounds Comprising Hybrid Carbon Black Grade UJ o

P o

3 s

TD P)

O c ui

Q 3_ O n n T sD o D a

T 3 - D P)

□. o — h iO c r ₊ n

I cr 3

□. 3

Q. P)

P cr c

S sr

O 3 ( 3S ^'

P)

O I

7 T3

O

CD

3 cr

Q_ c

P) sr w 3

P)

73 cr cr

P)

CO

03

7 _I 3 cn

73

The natural rubber compound comprising 30 phr of hybrid carbon black grade, compound Έ containing hybrid carbon black grade 'HI', demonstrates 100% modulus of 3.21 MPa, wherein the natural rubber compound, CE1, comprising 45 phr of carbon black, N234 shows 100% modulus of 2.49 MPa, table 4, which correspond to 29% improvement by the hybrid carbon black grade; elongation at break (%) for compound Έ is 534 and for 'CE1' it is 482 correspond to 11% improvement of elongation at break in Έ comprising 30 phr of hybrid carbon black grade with respect to rubber compound 'CE1'. The dynamic mechanical properties of natural rubber compound Έ is improved over natural rubber compound 'CE1', wherein Έ has 15 phr less carbon black than 'CE1'. The loss tangent of Έ (0.233) is lower about 13% than 'CE1' (0.267), table 4. The heat build up of Έ shows about 15% improvement over 'CE1' with comparable abrasion loss, table 4.

The natural rubber compound comprising 30 phr of hybrid carbon black grade, compound Έ containing hybrid carbon black grade Ή , demonstrates 100% modulus of 3.21 MPa, wherein the natural rubber compound, CE2, comprising 40 phr of carbon black, N234 shows 100% modulus of 2.06 MPa, table 4, which correspond to about 56% improvement by the hybrid carbon black grade. 300% modulus for compound Έ 13.2 MPa and for 'CE1' 11.2 MPa correspond to 18% improvement in Έ comprising 30 phr of hybrid carbon black grade with respect to rubber compound 'CE2'. The dynamic mechanical properties of natural rubber compound Έ is improved over natural rubber compound 'CE2', wherein Έ has 10 phr less carbon black than 'CE2'. The loss tangent of Έ (0.233) is lower about 6% than 'CE2' (0.247) with 12% improvement of storage modulus, table 4. The heat build up of Έ shows about 8% improvement over 'CE2' with 6% improvement of abrasion loss, table 4.

The SBR-BR rubber compound comprising 30 phr of hybrid carbon black grade, compound Έ2', containing hybrid carbon black grade Ή , demonstrates loss tangent 0.88, wherein SBR-BR compound, CE5, comprising 45 phr of carbon black, N234 shows loss tangent of 1.33, table 5, which correspond to 17% improvement by the hybrid carbon black grade. The heat build up of Έ2' shows about 12% improvement over 'CE5' with comparable abrasion loss, table 5.

The SBR-BR rubber compound comprising 30 phr of hybrid carbon black grade, compound Έ2', containing hybrid carbon black grade Ή , demonstrates loss tangent 0.88, wherein SBR-BR compound, CE6, comprising 40 phr of carbon black, N234 shows loss tangent of 1.00, table 5, which correspond to 14% improvement by the hybrid carbon black grade. The heat build up of Έ2' shows about 7% improvement over 'CE6' with c abrasion loss, table 5.

The mechanical, dynamic mechanical, abrasion loss performance, heat build up of natural rubber and SBR-BR rubber compounds comprising hybrid carbon black grade shows improvement with respect to natural rubber and SBR-BR rubber compounds comprising carbon black, 40 to 45 phr, with 10 -15 phr lower amount of addition of hybrid carbon black grade.

However, the mechanical properties of natural rubber and SBR-BR rubber compounds comprising 30 phr of hybrid carbon black grade, Ή . is only improved than the natural rubber and SBR-BR rubber compounds comprising 30 and 35 phr of N234 carbon black.

When comparatively higher amount of carbon black, N234, 60 phr is incorporated in natural rubber, the rubber compound 'CE9', and compared with natural rubber compound Έ4' comprising 48 phr of hybrid carbon black, Ή3', the tensile strength of Έ4' is improved from 23.1 MPa to 26.0 MPa, 13% higher, table 4. Similarly, the compound Έ4' shows 12 % and 20% higher elongation at break and 100% modulus over compound 'CE9' respectively. The loss tangent of Έ4' (0.288) is lower about 10% than 'CE9' (0.319), table 4. The heat build up of Έ4' shows about 19% improvement over 'CE9' with 8 % improvement in abrasion loss, table 4. When comparatively higher amount of carbon black, N234, 60 phr is incorporated in SBR-BR rubber, the rubber compound 'CE10', and compared with SBR-BR compound Έ6' comprising 48 phr of hybrid carbon black, Ή3', the 100% modulus of Έ6' is improved from 1.84 MPa to 2.23 MPa, 21% higher, table 5. The loss tangent of Έ6' (0.292) is lower about 12% than 'CE10' (0.331), table 5. The heat build up of Έ6' shows about 12% improvement over 'CE10' with 5 % improvement in abrasion loss, table 5.

The mechanical, dynamic mechanical, abrasion loss performance, heat build up of natural rubber and SBR-BR rubber compounds comprising hybrid carbon black grade shows improvement with respect to natural rubber and SBR-BR rubber compounds comprising carbon black, 60 phr, with 10 -12 phr lower amount of addition of hybrid carbon black grade.

Carbon black, N375, 60 phr, when incorporated in natural rubber and SBR-BR the rubber compound 'CE11' and 'CE12' respectively, and compared with natural rubber and SBR-BR compound Έ7' and Έ9' respectively comprising 52 phr of hybrid carbon black, Ή4', the loss tangent of Έ7' (0.282) is lower about 5% than 'CEi (0.295), table 4 and , the loss tangent of Έ9' (0.255) is lower about 13% than 'CE12' (0.293), table 5. The heat build up of Έ7' is lower about 7% than 'CEi , table 4 and, the heat build up of Έ9' is lower about 6% than 'CE12', table 5. For both rubber compounds comprising hybrid carbon black grade, H4, 52 phr, the abrasion loss is comparable with rubber compounds comprising carbon black, N375, 60 phr.

Carbon black, N375, 60 phr, when incorporated in natural rubber and SBR-BR the rubber compound 'CE11' and 'CE12' respectively, and compared with natural rubber and SBR-BR compound Έ8' and Έ10' respectively comprising 48 phr of hybrid carbon black, Ή5', the loss tangent of Έ8' (0.254) is lower about 14% than 'CEi (0.295), table 4 and , the loss tangent of Έ10' (0.238) is lower about 19% than 'CE12' (0.293), table 5. The heat build up of Έ8' is lower about 12% than 'CE11', table 4 and, the heat build up of Έ10' is lower about 12% than 'CE12', table 5. For both rubber compounds comprising hybrid carbon black grade, H5, 48 phr, the abrasion loss is comparable with rubber compounds comprising carbon black, N375, 60 phr.

The natural rubber compound comprising 52 phr of hybrid carbon black grade, compound Έ1 containing hybrid carbon black grade Ή6', is compared with natural rubber compound CE13 and CE14 containing N660 carbon black of 70 and 60 phr respectively. It is observed that the natural rubber compound Ell shows 5.2% improvement in tensile strength and 19% improvement in elongation at break with respect to natural rubber compound CE13, wherein, the natural rubber compound Ell shows 5.3% improvement in tensile strength and 23% improvement in elongation at break with respect to natural rubber compound CE14.

The natural rubber compound comprising 30 phr of hybrid carbon black grade, compound Έ12' containing hybrid carbon black grade Ή7', demonstrates 100% modulus of 3.95 MPa, wherein the natural rubber compound, 'CE15', comprising 40 phr of carbon black, N134 shows 100% modulus of 2.45 MPa, table 4, which correspond to 61% improvement by the hybrid carbon black grade; 300% modulus for compound Έ12' is 14.8 MPa and for 'CE15', 12.1 MPa correspond to 22% improvement. The dynamic mechanical properties of natural rubber compound Έ12' is improved over natural rubber compound 'CE15', wherein Έ12' has 10 phr less carbon black than 'CE15'. The loss tangent of Έ12' (0.220) is lower about 12% than 'CE15' (0.249) with improvement of storage modulus from 6.98 MPa for 'CE15' to 8.12 MPa for Έ12', about 16% improvement, table 4. The heat build up of Έ12' shows about 12% improvement over 'CE15', table 4.

The SBR-BR rubber compound comprising 30 phr of hybrid carbon black grade, compound Έ13' containing hybrid carbon black grade Ή7', demonstrates 100% modulus of 1.78 MPa, wherein the SBR-BR compound, 'CE16', comprising 40 phr of carbon black, N134 shows 100% modulus of 1.54 MPa, table 5, which correspond to 15% improvement by the hybrid carbon black grade; 300% modulus for compound Έ13' is 6.45 MPa and for 'CE16', 5.61 MPa correspond to 15% improvement. The dynamic mechanical properties of SBR-BR compound Έ13' is improved over SBR-BR compound 'CE16', wherein Έ13' has 10 phr less carbon black than 'CE16'. The loss tangent of Έ13' (0.217) is lower about 12% than 'CE16' (0.246) with improvement of storage modulus from 4.95 MPa for 'CE16' to 5.49 MPa for 'E13', about 11% improvement, table 5. The heat build up of Έ13' shows about 9% improvement over 'CE16', table 5.

The SBR-BR compounds, Έ15' and Έ16', table 5, comprising hybrid carbon black grade Ή9' and Ή10', demonstrate inferior tensile strength, elongation at break, loss tangent, abrasion loss and heat build up properties compared with SBR-BR compound 'CE10', table 5.

Present invention covers the carbon black range, which can be used for rubber for different applications, specifically, in tyre application. For carbon black with low surface area, N660 the performance enhancement due to hybrid carbon black grade is marginal. Further, lowering of surface area of carbon black for developing hybrid carbon black grade may not enhance the performance of rubber compound. Improvement of the properties of the rubber compounds incorporating the carbon black of up to Iodine number 19 mg/g is anticipated.

For carbon black with high surface area, N134 the performance enhancement due to hybrid carbon black grade is significant. For rubber and tyre application on higher surface area side carbon black of 1G0 series N115 is used. Beyond that larger surface area limit, the carbon black may also create dispersion issue.

Thus the present invention exhibits significant improvement of properties of rubber obtained by selective incorporation of hybrid carbon black grade comprising 2-3 phr rGO in its composition such that the same can potentially be used for the preparation of similar rubber with reduction of carbon black by an extent of 10-15 phr i.e. enabling replacement of rubber comprising 45 to 60 phr carbon black with much lighter analogues.