DESC:TECHNICAL FIELD
The present invention relates to the field of Polymer Technology. The present invention in particular relates to tyre innerliner rubber composition method of preparation thereof.
BACKGROUND
As advanced industrialization progresses around the world, environmental pollution is emerging as a serious problem.
Use of sustainable development goal materials provides a healthy environment i.e., work towards less carbon footprint, protects natural resources i.e., it avoids air and land pollution, it ensures that we can continue to use natural resources without depleting them i.e., we can reduce the depletion of natural resources and it helps in achieve long term economic growth.
In response to this, interest in the environment is increasing, and there is a tendency for environmental regulations to be tightened in all industries.
Publication no. IN202241033225 relates to a motorcycle tyre tread base rubber composition using recovered carbon black and its method thereof. A motorcycle tyre tread base rubber composition includes 100 parts by weight of a rubber; with the tri-blend NR, SBR and PBR or NR and PBR blend; produced using conventional reinforcing carbon black grade N220 or N330 replaced with 5 to 20 phr of recovered carbon black provides better processing properties, lower Payne effect, lower rolling resistance along with high rubber elasticity.
Publication no. US20130023595 discloses a regenerated rubber, a method and apparatus for obtaining regenerated rubbers from vulcanized crumb rubber, such as rubber from scrap. The apparatus is a thermokinetic mixer having the particularity to have an air tight stationary chamber with inner non-uniform surface. The method comprises the steps of raising the speed of the rotor shaft in order to increase a temperature of a mixture made of vulcanized crumb rubber and a lubricant, such as oil, until a devulcanizing temperature is reached; and reducing the temperature of the mixture to a lower temperature during a second period of time. The method of the invention is environmentally friendly or green, since the regeneration method does not use chemicals, includes a shorter period of treatment at higher temperature avoiding the risks of rubber cracking and spontaneous combustion, and further allowing mass-production of regenerated rubber with lower energy consumption.
Publication no. CN113528169 discloses intelligent waste rubber recycling equipment and a working method thereof, belonging to the technical field of waste rubber recycling. According to the invention, intelligent production line control is carried out by adopting an intelligent PID control principle. The intelligent waste rubber recycling equipment comprises a cracking system, a condensation system, a waste heat recovery system, a granulation system, a drying and screening system and a packaging system, wherein a cracking kettle is adopted for the cracking system; the cracking system is used for cracking waste rubber tires into rubber waste residues and pyrolysis gas; the pyrolysis gas is conveyed into the condensation system through the cracking kettle; he condensation system is installed to store an oil product prepared from the pyrolysis gas into an oil storage tank; and the condensation system stores the pyrolysis gas which cannot form the oil product into a gas storage cabinet.
Publication no. CN114989539 relates to an inner liner rubber composition of a high-airtightness tire, a preparation method and application of the inner liner rubber composition and the tire. The rubber composition is prepared by mixing the following raw materials in parts by weight: 100 parts of brominated butyl rubber, 5-35 parts of high molecular weight reclaimed rubber, 50-70 parts of carbon black, 10-20 parts of inorganic filler, 4-8 parts of softening oil and 3-7 parts of resin, the high-molecular-weight reclaimed rubber material is prepared by pretreating waste rubber powder, a softening agent and an activating agent in a stirrer and then carrying out desulfurization reaction in a screw extruder, the molecular weight Mn of the high-molecular-weight reclaimed rubber material is 12000-18000 g/mol, and the sol content is 30%-50%. By means of the design, the air tightness and the machining process performance of the tire airtight layer are remarkably improved, and it is guaranteed that the rolling resistance, dynamic fatigue aging and other performance are slightly improved or basically kept unchanged
Publication no. KR20090068400 relates to a tire inner liner rubber composition to improve air resistance permeation and crack resistance. A tire inner liner rubber comprises: 60-100 weight part of halogenated butyl rubber, 0-40 weight part of natural rubber, 10-40 weight part of recycled butyl rubber, 40-70 weight part of carbon black, 1-7 weight part of waste tire minute powder. The waste tire minute powder is pulverized at room temperature has the particle size of over 100 mesh.
Publication no. CN114989485 relates to a method for selectively breaking vulcanized rubber crosslinking bonds, application, equipment and a tire thereof. The method comprises the following steps: pretreating waste rubber powder, a softening agent and an activating agent in a stirrer at 80-120 DEG C for 30-60 minutes, standing at 60-80 DEG C for 2-4 hours, adding into a screw extruder, and controlling the temperature T1 of a heating section of the extruder to be more than 150 DEG C and less than 180 DEG C, the temperature T2 of a desulfurization section to be more than 165 DEG C and less than 210 DEG C, and the temperature T3 of a cooling section to be more than 170 DEG C and less than 200 DEG C; after reacting for 30-40 minutes, extruding from a mouth mold of a screw extruder to obtain low-temperature desulfurized reclaimed rubber; wherein the length L2 of the desulfurization section in the screw extruder and the gaps d21 and d22 between the eccentric screw and the side wall meet the condition that (d21-d22)/L2 is more than 0.012 and less than 0.022; the temperature T1 of the heating section and the temperature T2 of the desulfurization section meet the condition that T2-T1 is more than 15 DEG C and less than 30 DEG C. The invention develops the high-molecular-weight reclaimed rubber and the production process thereof, and the high-molecular-weight reclaimed rubber is applied to the formula of the sidewall, the tread and the inner liner, so that the tire performance is improved, and the appearance quality is improved.
Publication no. US6959744 relates to a tire having a rubber tread comprised of cap/base construction where the tread cap layer is the running surface of the tread having a lug and groove configuration and the tread base layer underlies the tread cap layer wherein the base layer provides a transition zone between the tread cap layer and the remainder of the tire carcass and is not intended to be ground-contacting.
Publication no. US8662123 relates to a tire having a rubber tread comprised of cap/base construction where the tread cap layer provides the running surface of the tread and the tread base layer underlies the tread cap layer and thereby provides a transition between the tread cap layer and the tire carcass. For this invention, the tread cap layer is comprised of a plurality of individual circumferential load-bearing zones of rubber compositions, which exhibit graduated physical properties, and which extend from the outer running surface of the tread cap layer radially inward to said tread base layer. In one aspect, the zoned rubber tread cap layer and rubber tread base layer are co-extruded together to form a unit as an integral tread rubber composite.
Publication no. CN109627509 provides a tread rubber material of a low-rolling resistance all-steel radial tire and a preparation method thereof. The tread rubber material is mainly prepared by mixing, by mass, 80-100 parts of natural rubber, 0-20 parts of butadiene rubber, 20-50 parts of carbon black, 10-30 parts of white carbon black, and 1-4 parts of a silane coupling agent, the preparation comprises the following steps of adding the white carbon black and the silane coupling agent after the natural rubber and the butadiene rubber are pressed into a plug to be mixed to obtain master batch, standing for 8-24 hours, and adding carbon black for continuous mixing.
Reference made to an article entitled “Goodyear Develops 70% Sustainable-Material Tire with Industry-Leading Innovations” by Goodyear, Jan. 5, 2022 which talks about the release of a demonstration tire with 70% sustainable-material content, including industry-leading innovations. We set an ambitious goal in 2020 to create a tire made 100% from sustainable materials in 10 years. This is an exciting achievement that demonstrates our commitment to increasing the use of sustainable materials in our tires. The 70% sustainable-material tire includes 13 featured ingredients across nine different tire components.
Publication no. WO2015054685A1 relates to the rubber composites containing macro-, micro-, and nano-sized fillers made from agricultural, industrial, and food processing wastes, methods of making the same, and articles fabricated therefrom. In a particular embodiment described herein is a rubber composite comprising a) a rubber component selected from the group consisting of: a natural rubber component; and a synthetic rubber component; b) a crosslinking system; one or more accelerators; one or more activators; and a filler comprising vegetable waste, mineral waste, lignocellulosic waste, or a combination thereof. In certain embodiments, the total filler content of a filler-rubber composite is selected from a group consisting of: about 1 PHR; about 2 PHR; about 3 PHR; about 4 PHR; about 5 PHR; about 10 PHR; about 15 PHR; about 20 PHR; about 25 PHR; about 30 PHR; about 35 PHR; about 40 PHR; about 45 PHR; about 50 PHR; about 55 PHR; about 60 PHR; about 65 PHR; about 70 PHR; about 75 PHR; about 80 PHR; about 85 PHR; about 90 PHR; about 95 PHR; and about 100 PHR
Publication no. US2023174743 relates to the rice husk ash silica (synthetic amorphous silica from rice husk ash) providing an exceptionally good combination of properties when used in certain tire tread rubber formulations, such as an excellent combination of traction, tread-wear, and rolling resistance. These tread rubber formulations are comprised of a blend of high cis-1,4-polybutadiene rubber and a solution styrene-butadiene rubber which is preferably functionalized with amine groups, siloxy groups, thiol groups, carboxyl groups, or groups that are reactive with hydroxyl groups present on the precipitated rice husk ash silica.
Publication no. JP2021195534 relates to the rubber composition for tires containing 100 parts by weight of raw rubber, 1 to 20 parts by weight of a lignin-based antioxidant, and 0.1 to 3 parts by weight of a crosslinking agent. The present invention relates to a rubber composition for tires that has an excellent antioxidant effect by using the present invention as an antioxidant without using conventional petroleum-based antioxidants
Similarly, in the tire industry, environmental regulations related to tire materials, manufacturing methods, etc. are established and managed by country, and it is predicted that environmental regulations will be further strengthened in the future. Active research into gentle tires is required.
In order to overcome above listed prior art, the present invention aims to provide a tyre innerliner rubber composition using sustainable development goal materials and its method of preparation thereof. The present invention discusses utilizes 70-95% sustainable development goal materials for tire innerliner rubber composition i.e., only in a single component tyre innerliner.
OBJECTS OF THE INVENTION
The principal object of the present invention is to provide a tyre innerliner rubber composition using sustainable development goal materials and its method of preparation thereof.
Another object of the present invention is to provide a tyre innerliner rubber composition that is inexpensive to produce.
Yet another object of the present invention is to reduce carbon footprint.
Yet another object of the present invention is to provide better barrier properties.
SUMMARY
In one aspect of the present disclosure, a tyre inner line rubber composition is provided.
The tyre innerliner rubber composition includes low aroma natural rubber reclaim ranges from 180-200phr. The tyre inner line rubber composition further includes butyl reclaimed rubber ranges from 20-40 phr. The tyre innerliner rubber composition further includes recovered carbon black ranges from 10-50 phr. The tyre innerliner rubber composition further includes vulcanizing activator ranges from 2-3 phr. The tyre innerliner rubber composition further includes vulcanizing activator ranges from 1-8 phr. The tyre innerliner rubber composition further includes antidegradant ranges from 1-3 phr. The tyre innerliner rubber composition further includes primary accelerator ranges from 1-3 phr. The tyre innerliner rubber composition further includes sulfur ranges from 1-3 phr.
In some aspects of the present disclosure, the low aroma natural rubber reclaim is characterized by acetone extract or low boiling material content ranges from 5-9%, specific gravity ranges from 1.10 to 1.20, and Mooney viscosity ML (1+4) at 100°C ranges from 20 to 40 MU.
In some aspects of the present disclosure, the butyl reclaim rubber is characterized by acetone extract or low boiling material content ranges from 5-9%, specific gravity ranges from 1.120 to 1.160, and Mooney viscosity ML (1+4) at 100°C ranges from 35 to 45 MU.
In some aspects of the present disclosure, the vulcanizing activator is zinc oxide and Stearic acid.
In some aspects of the present disclosure, the antidegradant is N-(1,3-dimethylbutyl)-N’-phenyl-p-phenylenediamine.
In some aspects of the present disclosure, the primary accelerator is n-tert-butyl-2-benzothiazyl sulfenamide.
In some aspects of the present disclosure, the composition exhibits a reduction in oxygen transmission rate by at least 59% compared to a composition made of natural rubber and conventional carbon black.
In some aspects of the present disclosure, the zinc oxide and stearic acid form a zinc soap complex, improving the solubility of zinc oxide in the compound and enhancing the efficiency of the vulcanization process.
In second aspect of the present disclosure, a method of preparing a tyre innerliner rubber composition, the method includes preparation of master batch that includes charging a Banbury mixer with low aroma natural rubber reclaim in an amount ranges from 180-200 phr, characterized by acetone extract or low boiling material content of 5-9%, specific gravity of 1.10-1.20, and Mooney viscosity ML (1+4) at 100°C of 20-40 MU, and Butyl reclaimed rubber in an amount ranges from 20-40 phr, characterized by acetone extract or low boiling material content of 5-9%, specific gravity of 1.120-1.160, and Mooney viscosity ML (1+4) at 100°C of 35-45 MU. The preparation of master batch further includes adding recovered carbon black in an amount ranges from 10-50 phr, wherein the recovered carbon black has an iodine adsorption number of 75-90 mg/gm, oil absorption number of 100-120 cc/100 gm, and nitrogen surface area of 65-75 m²/gm. The preparation of master batch further includes incorporating zinc oxide in an amount ranges from 2-5 phr and stearic acid in an amount ranges from 1-3 phr, to form a zinc soap complex for improved vulcanization efficiency. The preparation of master batch further includes adding N-(1,3-dimethylbutyl)-N’-phenyl-p-phenylenediamine (6PPD) as an anti-degradant in an amount ranges from 1-3 phr, to enhance resistance to thermo-oxidative aging. The preparation of master batch further includes mixing the components in the Banbury mixer at a head temperature of 75-100°C and a rotor speed of 45-65 rpm, following a mixing cycle comprising an initial mixing period of 30-80 seconds for the rubber components, addition of fillers and rubber chemicals followed by mixing for 120-260 seconds, sweeping the orifice and mixing for an additional 45-80 seconds. The preparation of master batch further includes dumping the rubber compound at a temperature of 145-160°C; and sheeting it out using a laboratory two-roll mill to obtain a master batch.
The method further includes preparation of final batch that includes charging the Banbury mixer with the master batch.
The preparation of final batch further includes mixing the master batch for 5-45 seconds, followed by the addition of N-tert-butyl-2-benzothiazyl sulfenamide (TBBS) as a delayed action accelerator in an amount ranges from 1-3 phr, and Sulfur as a vulcanizing agent in an amount ranges from 1-3 phr.
The preparation of final batch further includes mixing the batch for 50-120 seconds at a rotor speed of 45-65 rpm. The preparation of final batch further includes dumping the final rubber compound at a temperature of 95-110°C and sheeting it out using a laboratory two-roll mill to achieve uniform distribution of materials.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Various embodiments of the disclosure are discussed in detail below. While specific implementations are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations may be used without parting from the spirit and scope of the disclosure. Thus, the following description and drawings are illustrative and are not to be construed as limiting. Numerous specific details are described to provide a thorough understanding of the disclosure. However, in certain instances, known details are not described in order to avoid obscuring the description.
References to one or an embodiment in the present disclosure can be references to the same embodiment or any embodiment; and, such references mean at least one of the embodiments.
Reference to "one embodiment", "an embodiment", “one aspect”, “some aspects”, “an aspect” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Moreover, various features are described which may be exhibited by some embodiments and not by others.
The terms used in this specification generally have their ordinary meanings in the art, within the context of the disclosure, and in the specific context where each term is used. Alternative language and synonyms may be used for any one or more of the terms discussed herein, and no special significance should be placed upon whether or not a term is elaborated or discussed herein. In some cases, synonyms for certain terms are provided.
A recital of one or more synonyms does not exclude the use of other synonyms.
The use of examples anywhere in this specification including examples of any terms discussed herein is illustrative only, and is not intended to further limit the scope and meaning of the disclosure or of any example term. Likewise, the disclosure is not limited to various embodiments given in this specification. Without intent to limit the scope of the disclosure, examples of instruments, apparatus, methods and their related results according to the embodiments of the present disclosure are given below. Note that titles or subtitles may be used in the examples for convenience of a reader, which in no way should limit the scope of the disclosure. Unless otherwise defined, technical and scientific terms used herein have the meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. In the case of conflict, the present document, including definitions will control.
Additional features and advantages of the disclosure will be set forth in the description which follows, and in part will be obvious from the description, or can be learned by practice of the herein disclosed principles. The features and advantages of the disclosure can be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the disclosure will become more fully apparent from the following description and appended claims, or can be learned by the practice of the principles set forth herein.
As mentioned before, there is a need for technology that overcomes these drawbacks associated with the prior arts. The present disclosure, therefore, also provides a tyre innerliner rubber composition. The present disclosure also provides a method of preparing tyre innerliner rubber composition.
In some aspects of the present disclosure, a tyre innerliner rubber composition is provided.
The tyre innerliner rubber composition includes low aroma natural rubber reclaim, butyl reclaimed rubber, recovered carbon black, vulcanizing activator, antidegradant (N-(1,3-dimethylbutyl)-N’-phenyl-p-phenylenediamine), primary accelerator, and sulfur.
In some aspects of the present disclosure, the low aroma natural rubber reclaim ranges from 160 phr – 200 phr, more preferably ranges from 180-200 phr.
In some aspects of the present disclosure, the butyl reclaimed rubber ranges from 20 phr – 80 phr, more preferably from 20-40 phr. In some aspects of the present disclosure, the recovered carbon black ranges from 10-50 phr. In some aspects of the present disclosure, the vulcanizing activator ranges from 1-8 phr. In some aspects of the present disclosure, the (N-(1,3-dimethylbutyl)-N’-phenyl-p-phenylenediamine) ranges from 1-3 phr. In some aspects of the present disclosure, the primary accelerator ranges from 1-3 phr. In some aspects of the present disclosure, vulcanizer the sulfur ranges from 1-3 phr.
In some aspects of the present disclosure, the low aroma natural rubber reclaim is characterized by acetone extract or low boiling material content ranges from 5-9%, specific gravity ranges from 1.10 to 1.20, and Mooney viscosity ML (1+4) at 100°C ranges from 20 to 40 MU.
In some aspects of the present disclosure, the butyl reclaim rubber is characterized by acetone extract or low boiling material content ranges from 5-9%, specific gravity ranges from 1.120 to 1.160, and Mooney viscosity ML (1+4) at 100°C ranges from 35 to 45 MU.
In some aspects of the present disclosure, the vulcanizing activator is zinc oxide and stearic acid.
In some aspects of the present disclosure, the primary accelerator can be selected from sulfenamide types, more particularly n-tert-butyl-2-benzothiazyl sulfenamide.
In some aspects of the present disclosure, the vulcanizer can be selected from sulfur or oil treated sulfur.
In some aspects of the present disclosure, the composition exhibits a reduction in oxygen transmission rate by atleast 59% compared to a composition made of natural rubber and conventional carbon black.
In some aspects of the present disclosure, the zinc oxide and stearic acid form a zinc soap complex, improving the solubility of zinc oxide in the compound and enhancing the efficiency of the vulcanization process.
In some aspects of the present disclosure, the tyre innerliner rubber composition may include 75-99% sustainable development goal materials, reclaim rubber or combination of reclaim rubber and butyl reclaim or Halobutyl reclaim.
In some aspects of the present disclosure, the Process aid can be selected from pyrolysis oil or from renewable resources such as naturally occurring cold pressed oil like mustard oil etc., or any of the resins type C5/C9, C5 or hydrocarbon resin or without any process aid
Recovered carbon black as a filler, activators, anti-degradants, vulcanization agent, and primary accelerators.
The present invention relates to a tyre innerliner rubber composition and its method of preparation which is capable of improved barrier properties. The invention also relates to tyres comprising the innerliner composition of the present invention.

Table 1: Tyre innerliner rubber composition in Phr
Ingredients Rubber composition, Control Rubber Composition,
Formulation related to invention
C1, Phr C2, Phr F1, Phr F1, % F2, Phr F2, %
NR 1 90.00 100 - - - -
Low Aroma NR Reclaim (SDG Material) 2 180.00 71.43 200.00 79.37
Butyl Rubber 3 10.00 - - -
Butyl Reclaim ed Rubber (SDG Material) 4 20.00 7.94 - -
Carbon Black 5 50.00 50.00 - - -
Recovered Carbon Black (SDG Material) 6 40 15.87 40.0 15.87
Zinc Oxide 7 2.30 2.30 2.30 0.91 2.30 0.91
Stearic acid 8 1.20 1.20 1.20 0.48 1.20 0.48
Process Oil 9 4.00 4.00 - - - -
6PPD 10 2.00 2.00 2.00 0.79 2.00 0.79
TBBS 11 1.25 1.25 1.25 0.50 1.25 0.50
Sulfur 12 1.25 1.25 1.25 0.50 1.25 0.50
Total 162 162 252 100.0 252.0 100
% Sustainable Material used - - - 95.24 - 95.24

1- NR - Indian Standard Natural Rubber ISNR 20 with the Mooney Viscosity, ML (1+4) at 100°C is 65 to 80 MU and it is obtained from Mamparambil Rubber India Pvt Ltd, India.
2- Low Aroma Natural Rubber Reclaim – It is a superfine grade having acetone extract or low boiling material (LBM %) having 5% to 9% and Mooney viscosity ML (1+4) @100 Deg C ranging from 20 to 40 MU and its specific gravity ranging from 1.10 to 1.20 and it is from Eskegie Reclaims Private Limited, Tamilnadu, India.
3- Butyl Rubber – It is IMPRAMER R 1675 grade and it is from Reliance Sibur Elastomers Pvt Ltd, India.
4- Butyl Reclaimed rubber – It is superfine grade having acetone extract or low boiling material (LBM %) having 5% to 9% and Mooney viscosity ML (1+4) @100 Deg C ranging from 35 to 45 MU and its specific gravity ranging from 1.120 to 1.160. It is from Eswar Rubber Products (P) Ltd, Tamil Nadu, India.
5- Carbon Black –ASTM Grade N660 is the reinforcing filler GPF, General purpose filler having the Iodine adsorption No. 31 to 41 mg/gm, nitrogen surface area value between 30 to 40 m2/gm and COAN value ranges between 79 to 89 cc/100 gm and it is from Himadri Chemicals & Industries Limited, India.
6- Recovered Carbon Black – It is a sustainable development goal material recovered carbon black as a filler and having iodine adsorption number ranging from 75 to 90 mg/gm, oil absorption number ranging from 100 to 120 CC/100 gm and its specific surface area /nitrogen surface area ranging from 65 to 75 m2/gm and it is from Rathi Industrial Enterprises, India.
7- Zinc Oxide- It is used as an activator for the sulfur vulcanization of rubbers enhances the vulcanization efficiency and reduces the vulcanization time from Ambica Dhatu Private Limited, India.
8- Stearic acid- It is from 3F Industries Ltd., India. It is used as a Process aid. Also, Zinc oxide and Stearic acid are added to form zinc soap, improves the solubility of zinc oxide in the compound, and with the accelerator to form a complex, this complex reacts with sulfur to produce a strong cure activating system.
9- Process oil – MES oil– Mild Extracted Solvate or Low PCA oil is used to improve the processability of rubber compounds from IOCL Limited, India.
10- 6PPD- It is (N-(1,3-dimethylbutyl)-N’-phenyl-p-phenylenediamine) from Finorchem Limited, India. It is added to the rubber composition to provide resistance to thermo-oxidative ageing of elastomers.
11- TBBS - N-tert-butyl-2-benzothiazyl sulfenamide is a delayed action primary accelerator suitable for diene rubbers from Shandong Sunshine Chemical co ltd, China
12- Sulfur- Sulfur is the vulcanizing agent from The Standard Chemical Co. Pvt Ltd, India.
Examples:
Example 1: Characterization and Barrier properties of a rubber vulcanizate
The results presented demonstrate the superior barrier properties of the tyre innerliner rubber compositions (F1 and F2) compared to the control compositions (C1 and C2). The present composition F1, comprising low aroma NR Reclaim and Butyl Reclaim (180 phr: 20 phr) reinforced with recovered carbon black, exhibits an oxygen transmission rate (OTR) of 50.277, significantly lower than the OTR of 123.87 observed in the control composition C1, which is made of natural rubber and butyl rubber (90 phr: 10 phr) reinforced with conventional carbon black (N660) with the iodine surface area 31 to 41 mg/gm. This represents a 59.41% improvement in barrier properties. Similarly, the composition F2, consisting of 200 phr of low aroma NR Reclaim and recovered carbon black, achieves an OTR of 55.345, compared to 147.151 for control composition C2, showing an even greater improvement of 62.39%.
The compound properties are listed in Table 2 and Table 2A below:
The use of recovered carbon black with superior adsorption and oil absorption properties contributes significantly to the improved performance of the inventive compositions. This filler enables the formation of a denser and more uniform rubber matrix, thereby reducing oxygen permeability. Furthermore, the reliance on sustainable materials such as low aroma NR Reclaim and recovered carbon black aligns the inventive compositions with sustainable development goals (SDG) while delivering functional improvements.
The barrier properties were measured using a Mocon Make, Model MH 2/21, in accordance with ASTM F1927, ensuring reliable and standardized evaluation. The results validate that the inventive compositions not only outperform conventional formulations in terms of gas barrier effectiveness but also represent an eco-friendly and performance-optimized solution for tyre innerliners. These findings demonstrate the potential of the inventive formulations to enhance tyre durability, elasticity, and resistance to oxidative aging, while contributing to environmental sustainability.
Table 2: Characterization of Rubber Vulcanizate
Properties C1, Control F1 F1, Index
Oxygen Transmission Rate, OTR
(Lower the Index value is better) 123.87 50.277 40.59

Table 2A: Characterization of Rubber Vulcanizate
Properties C2, Control F2 F2, Index
Oxygen Transmission Rate, OTR
(Lower the index value is better) 147.151 55.345 37.61
In some other aspects of the present disclosure, a method of preparing a tyre innerliner rubber composition is provided.
The method of preparation of master batch that includes charging a Banbury mixer with low aroma natural rubber reclaim in an amount ranges from 180-200 phr, characterized by acetone extract or low boiling material content of 5-9%, specific gravity of 1.10-1.20, and Mooney viscosity ML (1+4) at 100°C of 20-40 MU, and Butyl reclaimed rubber in an amount ranges from 20-40 phr, characterized by acetone extract or low boiling material content of 5-9%, specific gravity of 1.120-1.160, and Mooney viscosity ML (1+4) at 100°C of 35-45 MU.
The preparation of master batch further includes adding recovered carbon black in an amount ranges from 10-50 phr, wherein the recovered carbon black has an iodine adsorption number of 75-90 mg/gm, oil absorption number of 100-120 cc/100 gm, and nitrogen surface area of 65-75 m²/gm.
The preparation of master batch further includes incorporating zinc oxide in an amount ranges from 2-5 phr and stearic acid in an amount ranges from 1-3 phr, to form a zinc soap complex for improved vulcanization efficiency.
The preparation of master batch further includes adding N-(1,3-dimethylbutyl)-N’-phenyl-p-phenylenediamine (6PPD) as an anti-degradant in an amount ranges from 1-3 phr, to enhance resistance to thermo-oxidative aging.
The preparation of master batch further includes mixing the components in the Banbury mixer at a head temperature of 75-100°C and a rotor speed of 45-65 rpm, following a mixing cycle comprising an initial mixing period of 30-80 seconds for the rubber components, addition of fillers and rubber chemicals followed by mixing for 120-260 seconds, sweeping the orifice and mixing for an additional 45-80 seconds.
The preparation of master batch further includes dumping the rubber compound at a temperature of 145-160°C.
The preparation of master batch further includes sheeting it out using a laboratory two-roll mill to obtain a master batch.
The method of preparation of final batch includes charging the Banbury mixer with the master batch.
The preparation of final batch further includes mixing the master batch for 5-45 seconds, followed by the addition of N-tert-butyl-2-benzothiazyl sulfenamide (TBBS) as a delayed action accelerator in an amount range from 1-3 phr, and Sulfur as a vulcanizing agent in an amount range from 1-3 phr.
The preparation of final batch further includes mixing the batch for 50-120 seconds at a rotor speed of 45-65 rpm.
The preparation of final batch further includes dumping the final rubber compound at a temperature of 95-110°C and sheeting it out using a laboratory two-roll mill to achieve uniform distribution of materials.
In some aspects of the present disclosure, mixing reclaim rubber or combination of reclaim rubber and butyl reclaim, recovered carbon black, activators, anti-degradants, vulcanization agent, and primary accelerators in a Banbury mixer.
In some aspects of the present disclosure, the method includes mixing reclaim rubber or combination of reclaim rubber and butyl reclaim recovered carbon black, reinforcing fillers, activators, anti-degradants, vulcanization agent, and primary accelerators in a Banbury mixer. In some aspects of the present disclosure, the method further includes dumping the rubber compound at a temperature in the range of 145°C to 160°C and sheeting it out in a laboratory two roll mill to obtain a master batch.
In some aspects of the present disclosure, the method further includes adding the master batch to the Banbury mixer and mixing it for 90 seconds to 160 seconds.
In some aspects of the present disclosure, the method further includes dumping the rubber compound at a temperature in the range of 120°C to 135°C and sheeting it out in the laboratory two roll mill.
In some aspects of the present disclosure, the method further includes adding accelerators and vulcanization agent to the final batch and mixing it for 50 to 120 seconds.
In some aspects of the present disclosure, the method further includes dumping the rubber compound at a temperature in the range of 95°C to 110°C and sheeting it out in the laboratory two roll mill to obtain the tyre innerliner rubber composition.
Advantages:
The present disclosure provides insight into a potential use of SDG’s Goal material from end-of-life tyres (ELT) as a reclaim rubber and recovered carbon black in tyre component and it improves circular economy.
The present disclosure provides a tyre innerliner rubber composition that reduces carbon footprint.
The present disclosure provides the tyre innerliner rubber composition provides excellent barrier properties.
The present disclosure provides the tyre innerliner rubber composition provides an insight into the use 70% to 99% use of SDG’s materials.
The implementation set forth in the foregoing description does not represent all implementations consistent with the subject matter described herein. Instead, they are merely some examples consistent with aspects related to the described subject matter. Although a few variations have been described in detain above, other modifications or additions are possible. In particular, further features and/or variations can be provided in addition to those set forth herein. For example, the implementation described can be directed to various combinations and sub combinations of the disclosed features and/or combinations and sub combinations of the several further features disclosed above. In addition, the logic flows depicted in the accompany figures and/or described herein do not necessarily require the particular order shown, or sequential order, to achieve desirable results. Other implementations may be within the scope of the following claims.
,CLAIMS:1. A tyre innerliner rubber composition comprising:
low aroma natural rubber reclaim ranges from 180-200 phr;
butyl reclaimed rubber ranges from 20-40 phr;
recovered carbon black ranges from 10-50 phr;
vulcanizing activator ranges from 1-8 phr;
antidegradant ranges from 1-3phr;
primary accelerator ranges from 1-3 phr; and
vulcanizer ranges from 1-3phr.
2. The tyre innerliner rubber composition as claimed in claim 1, wherein the low aroma natural rubber reclaim is characterized by acetone extract or low boiling material content ranges from 5-9%, specific gravity ranges from 1.10 to 1.20, and Mooney viscosity ML (1+4) at 100°C ranges from 20 to 40 MU.

3. The tyre innerliner rubber composition as claimed in claim 1, wherein the butyl reclaimed rubber is characterized by acetone extract or low boiling material content ranges from 5-9%, specific gravity ranges from 1.120 to 1.160, and Mooney viscosity ML (1+4) at 100°C ranges from 35 to 45 MU.

4. The tyre inner line rubber composition as claimed in claim 1, wherein the vulcanizing activator is zinc oxide and stearic acid.

5. The tyre innerliner rubber composition as claimed in claim 1, wherein the primary accelerator is n-tert-butyl-2-benzothiazyl sulfenamide.
6. The tyre innerliner rubber composition as claimed in claim 1, wherein the composition exhibits a reduction in oxygen transmission rate by atleast 59% compared to a composition made of natural rubber and conventional carbon black.

7. A method of preparing a tyre innerliner rubber composition, the method comprising:
(a) Preparation of Master Batch:
charging a Banbury mixer with low aroma natural rubber reclaim in an amount ranges from 180-200 phr, characterized by acetone extract or low boiling material content of 5-9%, specific gravity of 1.10-1.20, and Mooney viscosity ML (1+4) at 100°C of 20-40 MU, and Butyl reclaimed rubber in an amount ranges from 20-40 phr, characterized by acetone extract or low boiling material content of 5-9%, specific gravity of 1.120-1.160, and Mooney viscosity ML (1+4) at 100°C of 35-45 MU;
adding recovered carbon black in an amount ranges from 10-50 phr, wherein the recovered carbon black has an iodine adsorption number of 75-90 mg/gm, oil absorption number of 100-120 cc/100 gm, and nitrogen surface area of 65-75 m²/gm;
incorporating zinc oxide in an amount ranges from 2-5 phr and stearic acid in an amount ranges from 1-3 phr, to form a zinc soap complex for improved vulcanization efficiency;
adding N-(1,3-dimethylbutyl)-N’-phenyl-p-phenylenediamine (6PPD) as an anti-degradant in an amount ranges from 1-3 phr, to enhance resistance to thermo-oxidative aging;
mixing the components in the Banbury mixer at a head temperature of 75-100°C and a rotor speed of 45-65 rpm, following a mixing cycle comprising an initial mixing period of 30-80 seconds for the rubber components, addition of fillers and rubber chemicals followed by mixing for 120-260 seconds, sweeping the orifice and mixing for an additional 45-80 seconds;
dumping the rubber compound at a temperature of 145-160°C; and sheeting it out using a laboratory two-roll mill to obtain a master batch.
(b) Preparation of Final Batch:
charging the Banbury mixer with the master batch;
mixing the master batch for 5-45 seconds, followed by the addition of N-tert-butyl-2-benzothiazyl sulfenamide (TBBS) as a delayed action accelerator in an amount ranges from 1-3 phr, and Sulfur as a vulcanizing agent in an amount ranges from 1-3 phr;
mixing the batch for 50-120 seconds at a rotor speed of 45-65 rpm;
dumping the final rubber compound at a temperature of 95-110°C and sheeting it out using a laboratory two-roll mill to achieve uniform distribution of materials.