FIELD OF THE INVENTION

The present invention relates to the field of rubber. More particularly, it relates to rubber composition for a motor cycle tyre casing containing a naturally occurring Moringa oleifera gum for providing lower hysteresis with better adhesion properties.

BACKGROUND OF THE INVENTION

The manufacturing process for many rubber products, including tires, includes the step of forming by bonding unvulcanized rubber composition. In unvulcanized rubber composition for providing tackiness, the rubber composition, a tackifier may be incorporated. The tackifier usually smaller molecular weight than the rubber component, a glass transition point not exhibit rubber elasticity at room temperature or above resins is used. As the resins, para-tertiary-butylphenol-acetylene resin, alkylphenol resin such as p-octylphenol-formaldehyde resin, aromatic hydrocarbon resin, aliphatic hydrocarbon resin, petroleum resin, such as aliphatic cyclic hydrocarbon resin has been commonly used.

EP2733170A1 relates to a rubber composition and a tire comprising such a rubber composition. The rubber composition comprises, based on parts by weight per 100 parts by weight of elastomer (phr): at least one conjugated diene -based elastomer, preferably including at least one conjugated diene- based elastomer that contains one or more functional groups reactive with hydroxyl groups contained on silica; from 5 to 60 phr of at least one triglyceride vegetable oil; from 1 to 30 phr of a resin comprising at least one of a coumarone-indene resin, an alkylated hydrocarbon resin, an aromatic petroleum resin, a dicyclopentadiene resin and a styrene-alphamethylstyrene resin; from 30 to 140 phr of a reinforcing filler comprising: silica, or a combination of carbon black and silica; and a silica coupling agent reactive with hydroxyl groups contained on the silica and another different moiety interactive with carbon-to-carbon double bonds of the conjugated diene -based elastomer; wherein the rubber composition is free of oil extended elastomer.

Publication No. CN108948444 (A) relates to a multifunctional foamed insole which is prepared from the following raw materials in parts by weight: 100 parts of natural rubber, 15-17 parts of terpene resin, 15-17 parts of jute fibers, 10-12 parts of shell powder, 13-15 parts of talc powder, 19- 22 parts of jade powder, 8-10 parts of palygorskite, 7-9 parts of radiobarite powder, 6-8 parts of cortex moriradicis, 3-5 parts of moringa tree roots, 14-16 parts of diatomite, 7-8 parts of a coupling agent, 3-4 parts of azodicarbonamide, 3-5 parts of nano zinc oxide, 1-2 parts of stearic acid, 2-2.5 parts of sulfur, 1-1.5 part of an accelerant and 1.5-2 parts of an antiageing agent.

Publication No. CN 104059329 (A) relates to rubber characterized by including the following substances by weight: 14-20 parts of furfuryl alcohol resin, 21-30 parts of urea formaldehyde resin, 26-29 parts of polytetrafluoroethylene gum, 4-8 parts of silicon carbide, 9-14 parts of a formaldehyde solution, 16-17 parts of glacial acetic acid, 3-9 parts of resorcinol, 1-4 parts of paraformaldehyde, 1-9 parts of precipitated barium sulfate, 2-8 parts of Hoveniaacerba sawdust, 3-7 parts of camellia oleifera sawdust, 4-8 parts of Eucalyptus globules sawdust, 1-2 parts of anatase titanium dioxide, 0.5-1 part of nano-organic montmorillonite, and 3-4 parts of talcum powder. Natural product chitosan, moringaoleifera seeds, papain, strychnos seeds, have been used as coagulants.

Publication No. EP2143755 (Al) relates to methods for making shapeable composite materials or shaped articles from recycled materials comprising forming a crumb slurry by, in any order, increasing the particle size of a composition comprising white water waste from one or more emulsion or dispersion polymer and combining the white water waste polymer with one or more waste thermoset material, preferably, ground tire rubber (GTR), and, then processing the combined material wet or dry as a thermoplastic to form the composite material or article.

Useful coagulating agents include any known coagulation agents such as, for example, any chosen from a salt, such as sodium chloride or iron (ferric) chloride, i.e. FeC13, , iron (ferrous) sulfate, i.e. Fe2(SO4)3, alum, i.e. A12(SO4)3, magnesium sulfate, or preferably FeC13; an acid, such as a carboxylic acid, e.g. formic acid, or sulfuric acid to reduce the pH of the white water polymer to 4.5 or less, preferably 4.0 or less; a chemical coagulant and mixtures thereof. Other chemical coagulants may include alumina, aluminiumchlorohydrate, calcium oxide, polyacrylamide, sodium aluminate, and sodium silicate, and the like; and natural product coagulants may include chitosan, Moringa oleifera seeds, papain, strychnos seeds, and isinglass, among others.

Publication No. US2010167013 (Al) relates to thermoplastic roofing membranes comprising particles of crosslinked rubber and an aqueous (co)polymer dispersion. The thermoplastic roofing membranes are formed by combining particles of crosslinked rubber and a suspension polymer dispersion, or a coagulated aqueous latex (co)polymer dispersion, to form a mixture in aqueous dispersion, which aqueous dispersion mixture is subjected to solid state shear pulverization to form materials that can be processed as thermoplastics at crosslinked rubber concentrations of from 10 wt.% to as high as 95 wt.%, based on the total solids of the material. The method may further comprise kneading the pulverized product, followed by extrusion to form roofing membranes. Suitable methods of coagulation may include the addition of an acid, such as formic acid or sulfuric acid, or a salt, such as sodium chloride or iron (ferric) chloride. Other chemical coagulants may include alum, alumina, aluminiumchlorohydrate, aluminium sulfate, calcium oxide, iron (ferrous) sulfate, magnesium sulfate, polyacrylamide, sodium aluminate, and sodium silicate, and the like; and natural product coagulants may include chitosan, moringaoleifera seeds, papain, strychnos seeds, and isinglass, among others.

Publication No. AU2009202787 (Al) relates to methods of making shapeable composites in the form of finely divided materials or articles and the materials and articles produced by the methods, the methods comprising forming mixtures by (i) treating an aqueous thermoplastic acrylic or vinyl polymer to increase the particle size thereof to a weight average particle size of 1 nm or more, and, optionally, dewatering to form a crumb mixture; and (ii) combining a thermoplastic acrylic or vinyl polymer with one or more waste rubber vulcanizate having a sieve particle size ranging from 10 to 600 pm in the amount of from 15 to 95 wt.%, based on the total weight of polymer and rubber to form a crumb slurry, such that (ii) can take place before, during, after (i) but before any dewatering, or after any dewatering; and (iii) thermoplastic processing the mixture. Useful coagulating agents include any known coagulation agents such as, for example, any chosen from a salt, such as sodium chloride or iron (ferric) chloride, i.e. FeC13, iron (ferrous) sulfate, i.e. Fe2(SO4)-, alum, i.e. A12(SO4)3, magnesium sulfate, or preferably FeC13; an acid, such as a carboxylic acid, e.g. formic acid, or sulfuric acid to reduce the pH of the acrylic or vinyl polymer to 4.5 or less, preferably 4.0 or less; a chemical coagulant and mixtures thereof. Other chemical coagulants may include alumina, aluminiumchlorohydrate, calcium oxide, polyacrylamide, sodium aluminate, and sodium silicate, and the like; and natural product coagulants may include chitosan, moringaoleifera seeds, papain, strychnos seeds, and isinglass, among others.

Publication No. US2010016456 (Al) relates to methods of making composite materials comprising combining particles of crosslinked rubber with coagulated aqueous polymer dispersions to form a mixture in aqueous dispersion, and subjecting the aqueous dispersion mixture to solid state shear pulverization to form materials that can be processed as thermoplastics at crosslinked rubber concentrations of from 10 to as high as 95 wt. %, based on the total solids of the material. The method may further comprise kneading the pulverized product to form useful articles, such as roofing membranes and shoe soles. Suitable methods of coagulation may include the addition of an acid, such as formic acid or sulfuric acid, or a salt, such as sodium chloride or iron (ferric) chloride. Other chemical coagulants may include alum, alumina, aluminiumchlorohydrate, aluminium sulfate, calcium oxide, iron (ferrous) sulfate, magnesium sulfate, polyacrylamide, sodium aluminate, and sodium silicate, and the like; and natural product coagulants may include chitosan, moringaoleifera seeds, papain, strychnos seeds, and is in glass, among others.

The article entitled “Influence of Moringaoleifera derivatives in blends of PBAT/PLA with LDPE” talks about the polymerization of moringa oil (MO) was carried out assisted by microwaves without catalysts presence. There aren’t studies about the polymerization of MO using microwaves technology. Moringa’ s oil and its polymer (PMO) were used as a biodegrading agent for mixtures of low density polyethylene (LDPE) with poly(butylene adipate-co-terephthalate)/poly(lactic acid) (PBAT/PLA). The mixtures producted films that was characterized and submitted to biodegradation analysis in order to discuss the influence of moringa components. Results showed that both moringa components improved thermal properties and reduced the crystalline phase of the mixture. The addition of PMO had improved the biodegradation capacity up to five times while MO had improved it up to three times. The results showed the greatest influence of moringa components on biodegradation of mixtures with cited polymers [Cristiane Medina Finzi-Quintao, KatiaMonteiro Novack, Ana Claudia Bernardes-Silva, Thais Dhayane Silva, Lucas Emiliano Souza Moreira, LuizaEduardaMoraes Braga; Polimeros vol.28 no.4 Sao Carlos, Aug./Sept. 2018].

The article entitled “Moringa oleifera (Drum Stick Vegetable Fibre) Based Nanocomposite with Natural Rubber: Preparation and Characterizations” talks about bio based nanocomposites successfully developed using cellulose nano whisker as filler in natural rubber latex by water evaporation method. The cellulose nano whisker were prepared from “Moringa oleifera” (Drum Stick vegetable Fibre) by acid hydrolysis. The FTIR analysis provided clear evidence of the presence of nano CW in the NR matrix that can be observed by the absorption peaks at 1033 and 1057 cm-1 assigned to C-0 stretching of cellulose and TGA analysis showed the thermal stability of the nanocomposites increased with increasing CW, tensile strength and modulus values were also increased with CW addition. Hence the study shows that the cellulose nano whiskers from Moringa oleifera has improved the properties of natural rubber based composite and can be considered as a good natural reinforcing material for future applications [Sajithkumar, K.J., Visakh, P.M. & Ramasamy; E.V. Waste Biomass Valor 7: 1227, 2016].

Accordingly, there exists a need for rubber composition for motor cycle tyre casing containing naturally occurring Moringa oleifera gum.

OBJECTS OF THE INVENTION

It is the principal object of the present invention to provide rubber composition containing a naturally occurring Moringa oleifera gum for motor cycle tyre casing.

It is another object of the present invention to provide a motorcycle tyre casing rubber composition capable of providing lower hysteresis with better adhesion properties of rubber compound that are bonded to reinforcing cord.

It is another object of the present invention to provide a motorcycle tyre casing rubber composition capable of providing higher modulus and higher tensile strength.

It is another object of the present invention to provide a motorcycle tyre casing rubber composition capable of providing better ageing properties.

It is another object of the present invention to eliminate use of synthetic resins / petroleum based resins.

SUMMARY OF THE INVENTION

One or more of the problems of the conventional prior arts may be overcome by various embodiments of the present invention.

It is the primary aspect of the present invention to provide a rubber composition for motor cycle tyre casing, comprising of: one or more rubbers - 100 parts; reinforcing filler - 30 - 60 parts; activators - 1.5 - 5 parts; anti-degradants - 1.2 - 2.5 parts; vulcanization agent - 1.3 - 2.5 parts; primary accelerators - 1.2 - 2 parts; process aid - 2 - 15 parts; and

Moringa oleifera gum - 0.1 - 20 parts, wherein the Moringa oleifera gum is naturally occurring that contains the functional groups OH stretching, C-H stretching, CO stretching, C-C deformation and secondary OH.

It is another aspect of the present invention to provide a rubber composition for motor cycle tyre casing, wherein said rubbers are selected from one or more of natural rubbers and synthetic rubbers.

It is another aspect of the present invention to provide a rubber composition for motor cycle tyre casing, wherein reinforcing filler is carbon black of HAF - LS (High Abrasion Furnace - Low Structure) ASTM grade N326, N330, N660 or any of the ASTM grades of Carbon Black having the Iodine adsorption No. 77 to 87 mg/gm, tinting strength value between 106 to 117 % ITRB, statistical thickness surface area value between 71 to 77 m /gm.

It is another aspect of the present invention to provide a rubber composition for motor cycle tyre casing, wherein activator comprises zinc oxide, Zinc Complexes, stearic acid, any of the fatty acids, zinc stearate and combinations thereof.

It is another aspect of the present invention to provide a rubber composition for motor cycle tyre casing, wherein anti-degradant comprises 2,2,4-trimethyl-l,2-dihydroquinoline (TDQ), any of the types of paraphenyldiamines, secondary aromatic amines, benzimidazoles and combinations thereof.

It is another aspect of the present invention to provide a rubber composition for motor cycle tyre casing, wherein vulcanization agent is selected from one or more of sulphur and insoluble sulphur.

It is another aspect of the present invention to provide a rubber composition for motor cycle tyre casing, wherein primary accelerators comprises of N-cyclohexyl-2-benzothiazole sulfonamide (CBS) , N-terbutyl-2-benzothiazole sulfonamide (TBBS) and combinations thereof. It is another aspect of the present invention to provide a rubber composition for motor cycle tyre casing, wherein said process aid is aromatic oil.

It is another aspect of the present invention to provide a tyre comprising a tyre casing containing rubber composition comprising of naturally occurring Moringa oleifera gum.

It is another aspect of the present invention to provide a method of preparation of rubber composition for motor cycle tyre casing, comprising of steps: preparation of master batch by: initial mixing of selected rubbers; adding of 100 % reinforcing filler, rubber chemicals with Moringa oleifera gum, process aid - aromatic oil; mixing the added ingredients and sweeping down in the orifice and again mix; dumping the compound at temperature range between 125- 145 °C; sheet out the compound; preparation of final batch by: mixing the master batch compound with curatives i.e. Sulphur (vulcanizer) and CBS (accelerator); dumping at temperature range between 90 - 115 °C; and sheet out the compound.

It is another aspect of the present invention to provide a method of preparation of rubber composition for motor cycle tyre casing, wherein the master batch processing parameters are unloaded rotor speed of mixer is between range 55 and65 rpm, and head temperature of banbury mixer is of range 55 and 65°C.

It is another aspect of the present invention wherein the rubber composition is prepared by thermo mechanical process.

BRIEF DESCRIPTION OF DRAWINGS

Figure 1: represents the ATR FTIR spectra of Moringa oleifera gum. DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a motor cycle tyre casing composition and a tyre produced using this rubber composition, capable of providing lower hysteresis with better adhesion properties. The present invention provides for a rubber composition comprising of naturally occurring Moringa oleifera gum, containing the functional groups OH stretching, C-H stretching, C-0 Stretching, C-C deformation and secondary OH; and preparation method thereof.

In accordance with the present invention, there is provided a rubber composition comprising of 100 parts by weight of a rubber, preferably selected from one of natural rubber, synthetic rubber and its blends.

Particular embodimnet of the presetn invention comprises of a rubber composition comprising of 100 parts by weight of rubber selected from one or more of natural, synthetic rubber or its blend and upto 0.1 to 20 phr by weight of a naturally occurring Moringa oleifera gum.

In accordance with the present invention, a preferred embodiment of the present invention comprises of a rubber composition with rubber selected from natural rubber or synthetic rubber or its blend and further comprising of 30 - 60 phr by weight of reinforcing fillers, 1.5 - 5 parts of activators, 1.2 - 2.5 parts of anti-degradants, 1.3 - 2.5 parts of vulcanization agent / system, 1.2 - 2 parts of primary accelerators, 2- 15 parts of process aid.

In accordance with the present invention, there is provided a rubber composition comprising of carbon black preferably of HAF - LS (High Abrasion Furnace - Low Structure) ASTM grade N326, N330, N660 or any of the ASTM grades of Carbon Black having the Iodine adsorption No. 77 to 87 mg/gm, tinting strength value between 106 to 117 % ITRB, statistical thickness surface area value between 71 to 77 m /gm. as reinforcing filler.

Embodiments of the present invention comprises of Activators. Preferably the activators comprises of compounds of Zinc.

Particularly the activator comprises of zinc oxide, Zinc Complexes, stearic acid, any of the fatty acids, zinc stearate and combinations thereof as activator. Further, the present invention and its embodiments comprises of anti -degradants. Anti-degradant according to embodiments of the present invention comprises of 2,2,4-trimethyl-l,2- dihydroquinoline (TDQ), any of the types of paraphenyldiamines, secondary aromatic amines, benzimidazoles and combinations thereof.

Embodiments of the present invention comprises of vulcanizing agents or vulcanization system based on one of sulphur and insoluble sulphur.

Embodiments of the present invention comprises of accelerators, particularly primary accelerators selected from one or more of N-cyclohexyl-2- benzothiazole sulfonamide (CBS) and N-terbutyl-2- benzothiazole sulfonamide (TBBS), and aromatic oil as process aid.

Method of preparation of rubber composition comprising naturally occurring Moringa oleifera gum:

Mixing Sequence:

An embodiment of the present invention discloses a method of preparation of rubber composition comprising a naturally occurring Moringa oleifera gum.

A rubber composition prepared by a process which comprises the sequential mixing steps, thermo- mechanically mixing with the preparatory mixing step - master batch is as follows:

For demonstration of the invention the processing steps is carried out in a banbury mixer.

Step I: Mixing has been done with the head temperature of the banbury maintained between 55 to 65 °C and the unloaded rotor speed maintained between 55 to 65 rpm. The mixing cycle is to be followed as: a) Mixing chamber has been charged with the selected rubber and allowed to mix for 0 to 30 seconds b) and further, by adding 100% carbon black, rubber chemicals with Moringa oleifera gum, aromatic oil, and allowed to mix for 30 to 168 seconds, c) sweeping has been done in the orifice and allowed to mix for another 80 to 102 seconds, the compound has been dumped at the temperature in the range of 125°C to 145°C and sheeted out in the laboratory two roll mill.

Step II: Thermo mechanically mixing in atleast one preparatory mixing step - final batch is as follows: Mixing chamber charged with the master batch rubber compound and the curatives, and allowed to mix for 60 to 80 seconds and the compound has been dumped at the temperature in the range of up to the temperature 90°C to 115 °C. The final batch sheet out has been done in the laboratory two roll mill.

Examples:

The present invention will be explained further by examples, but the scope of the present invention, is not limited to these examples.

The present invention related to the rubber composition for motor cycle tyre casing using naturally occurring Moringa oleifera gum and to rubber compositions according to Table 1 manufacture thereof. The rubber composition according to the invention comprises of: a. The motor cycle tyre casing composition according to the invention, which can be used for the manufacture of a tyre, comprising 100 parts by weight of a natural rubber or synthetic rubber or its blends. b. Reinforcing filler, Carbon Black HAF - LS (High Abrasion Furnace - Low Structure) ASTM grade N326, N330, N660 or any of the ASTM grades of Carbon Black having the Iodine adsorption No. 77 to 87 mg/gm, tinting strength value between 106 to 117 % ITRB, statistical thickness surface area value between 71 to 77 m /gm used for the present invention is to provide the better mechanical properties. c. In accordance to the present invention, the Moringa oleifera gum used in the NR based rubber composition is to provide better adhesion properties along with lower hysteresis in a motor cycle tyre casing compound. Also, the Moringa oleifera gum identified the spectrum 1027.44 cm-1 which refers to secondary OH groups. The absorption band at 2919.51 cm’ ¹ refers to C-H stretching and 1604.31 cm’ ¹ indicates the CO stretching and 1435.38 cm’ ¹ indicates the C-C deformation, 3289.83 cm’ defers to OH stretching.

The Figure 1. represents the Attenuated total reflectance - Fourier transform infrared (ATR- FTIR) spectra of Moringa oleifera gum. d. CI Resin, grade is used in the compound is to compare with the Moringaoleifera gum used in the present invention to provide better adhesion properties. e. The other ingredients selected for the present invention is based on the conventional motor cycle tyre casing composition activator zinc oxide and stearic acid, antidegradant, TDQ, 2, 2, 4-trimethyl- 1 , 2-dihydroquinoline. f. The vulcanization system used in the present invention is based on Sulphur or insoluble Sulphur and on a primary accelerator N cyclohexyl-2-benzothiazole sulfenamide (CBS) or

N-ter-butyl-2-benzothiazole sulfenamide (TBBS).

Table 1: Rubber Composition in PHR

1- Indian Standard Natural Rubber ISNR 20 with the Mooney Viscosity, ML (1+4) @ 100°C is 75 MU.

2- ASTM Grade N326 from Birla Carbon, India

3- TDQ 2, 2, 4-trimethyl- 1 , 2-dihydroquinoline from Lanxess, India

4- CI (Coumarone indene) resin from Ishant Polychem, India.

5- MoringaOleifera gum from Miracle Tree Life Science, Madurai, India. 6- CBS (N-cyclohexyl-2-benzothiazolesulfenamide) from Nocil Limited, India.

Characterization of unvulcanized and vulcanized Rubber compound:

The compound properties are listed in Table 2 below:

Measurements and Tests: Ml. Better adhesion properties of reinforcing cord that are bonded to rubber compound by H adhesion test procedure.

The H adhesion test measurements are carried out with a Universal Testing Machine Instron Make, Model No: 5966 in accordance with ASTM D4776. The tyre cord construction used for H Adhesion test is Nylon 6: N22 1260/2.

Dynamic properties of the rubber vulcanizate:

M2. The dynamic properties of the rubber vulcanizate are measured on a dynamic mechanical analyzer (DMA Metravib +1000) in accordance with ASTM D5992 with a dynamic strain 0.1%, temperature sweep from -120 to +100°C, frequency: 20Hz in tension mode. Hysteresis is a measure of the amount of energy lost per cycle during deformation of an elastomer. Tangent delta, or the loss factor, is a measure of hysteresis and is the ratio of the loss modulus to the storage modulus.

M3. The tensile properties of the rubber compound accessed in accordance with ASTM D412.

M4. The ageing properties were evaluated in accordance with ASTM D 573/ ASTM D412. The dumbbell test specimens were aged in hot air ageing oven at 70 deg C for 168 hrs, 336 hrs and 100 deg C for 72 hrs.

The purpose of these tests is to measure the rubber compound properties of the compositions related to invention F2, against the control composition Fl. Two rubber composition based on NR formulation, reinforced by carbon black containing 5 phr Moringa oleifera gum (F2) against NR based formulation reinforced by carbon black containing 5phr Ciresin (Fl) are prepared and evaluated.

Table: 2

The present invention provides a 100 parts by weight of rubber composition F2, NR based rubber composition containing 5 phr Moringa oleifera gum gave adhesion property increased by 42.99 % (big) and 27.15% (small) when compared to NR based rubber composition containing 5 phr of CI resin Fl (Control).

The present invention provides a 100 parts by weight of rubber composition F2, NR based rubber composition containing 5 phr Moringa oleifera gum gave lower hysteresis i.e., tan delta at 100 deg C lowered by 8.09 % when compared to NR based rubber composition with CI resin Fl (Control).

The present invention provides a 100 parts by weight of rubber composition F2, NR based rubber composition containing 5 phr Moringa oleifera gum gave higher tensile strength and 300% modulus increased by 13.63% and 35.28% respectively when compared to NR based rubber composition with CI resin, Fl (Control).

The present invention provides a 100 parts by weight of rubber composition F2, NR based rubber composition containing 5 phr Moringa oleifera gum gave lower change in tensile strength properties in 70 Deg C at 168 hrs and 336 hrs lowered by 7.73% and 33.37% respectively when compared to NR based rubber composition with CI resin, Fl (Control). Also, similar trend is observed at 100 deg C for 72 hrs, F2 compound gave change in tensile strength lowered by 21.40 % when compared to control compound, Fl.

Hence, the present invention provides a 100 parts by weight of rubber composition F2, NR based rubber composition containing 5 phr Moringa oleifera gum containing rubber composition gave lower hysteresis with better adhesion properties of rubber compound with tyre cord. Also, the present invention provides 100 parts by weight of rubber composition F2, NR based rubber composition containing 5 phr Moringa oleifera gum containing rubber composition gave higher tensile strength and 300 % modulus along with better ageing properties when compared to NR based rubber composition control compound, Fl containing 5 phr CI resin.