FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
AND
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION (See section 10; rule 13)
TITLE OF THE INVENTION TIRE PUNCTURE SEALANT COMPOSITION
APPLICANT
CEAT LIMITED
of RPG HOUSE, 463, Dr. Annie Besant Road,
Worli, Mumbai 400 030, Maharashtra, India
Nationality: Indian
INVENTORS
GAURANG PARIKH, SREEJESH ARAYAMBATH AND
SUJITH S. NAIR
of Research & Development Department,
CEAT Limited, Getmuvala,
Chandrapura, Halol,
Vadodara-389350,
Gujarat, India
All are Indian National
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed

FIELD OF THE INVENTION
[0001] A tire sealant composition for application in pneumatic tires and method of production thereof is provided. The tire puncture sealant composition embodied in the present disclosure is applied inside the tire to effectively prevent air loss after tire is punctured on road/off road during running. The tire sealant composition of the present invention is developed demonstrates improved sealing performance and imparts high tackiness with inner line of tire reducing shrinkage and separation of sealant from the tire.
BACKGROUND OF THE INVENTION
[0002] Tires running on road/off road can undergo puncture by nails, screws or spines etc. which lead to under inflation. Under inflation is a very dangerous situation for tire performance as well as for the rider. While riding with punctured tire, rider sometimes is not able to identify loss in air or under inflation and continues to drive with under inflation. Because of under inflation there is increase in tire wear, tire heating and fuel consumption by vehicle. It also leads to reduction in resistance to punctures and cuts to tire, and sometimes under inflation may lead to fatal accidents.
[0003] To overcome these problems, various sealant formulations providing sealing of puncture in tires have been proposed. US20100331448A1 discloses a tire puncture sealant comprising rubber latex, and 1,3-propanediol, US20120041099 A1 reports a tire puncture sealant comprising a rubber latex and/or a resin emulsion, an acetylene alcohol and/or a derivative thereof. EP0798140 A2 discloses a sealant composition comprising a particulate, surface-activated, polymeric component dispersed

in a fluid medium comprising water, a freeze preventative selected from alkyl polyols, and latex. The formulations described in these patent applications manifest some disadvantages such as the insertion of sealant through valve upon the tire being punctured causes blockage of air valve because of ground rubber. In sealants containing isoprene rubber latex as a base and ethylene glycol as an anti-freezing agent, creaming tends to occur in long time storage.
[0004] Sealants having fibrous material may have issues in sealing the puncture if fluid enters into puncture when unaccompanied by fibrous material. Some tires are manufactured with a liner and built-in sealant, however are expensive. Built-in TPE sealants have issues of shrinkage after tire running since the coating of sealant gets disturbed.
[0005] US4337322 and US4588758 disclose a further development of tire sealant. These patents teach the use of asbestos fiber, ethylene glycol and detergent as main components in the valve-open type sealant. However, the employment of asbestos fiber is carcinogenic whereas ethylene glycol is toxic to the environment. Hence, inclusion of these components is not recommended attributed to the wide scale damage that could be caused to the environment.
[0006] US3981342 and US5295525 report a puncture sealing composition for a tubeless pneumatic tire comprising a fiber-free blend of a low molecular weight liquid elastomer, a high molecular weight solid elastomer, and a crosslinking agent.
[0007] A need exists, therefore, for a sealant composition that will eliminate or ameliorate the difficulties described. Also, the composition as herein

described completely fulfills all requirements concerning efficacy of puncture sealing performance, seal retention performance, however, without inclusion of any components that are either hazardous to human or harmful to the environment.
[0008] Accordingly, the objective of the present invention is to provide a sealant composition which overcomes the drawbacks present in the prior art compositions. The present inventors have endeavored to develop a sealant composition which is free of a solvent, fibrous material and/or a crosslinking agent resulting in a composition with improved ageing, recyclability, easy processability, environment friendly, and economical. Furthermore, the recyclability and reusability of sealant rubber makes it a completely green solution with least carbon foot print and economy of operation. The process employed for its preparation is environmental friendly, cost effective and easily scalable.
[0009]Particularly, the tire sealant composition described in the present invention imparts high tackiness and excellent sealing performance over the conventionally known sealant compositions which are a significant technical advancement over the state of art.
OBJECT OF THE INVENTION
[0010] It is an object of the present invention to arrive at a sealant
composition made of fibers free material and is additionally solvent free;
environment friendly, economical, with excellent puncture sealing
performance without affecting riding and handling experience of vehicle.

[0011] It is a further object of the present invention to provide a sealant composition with improved tackiness and flowability.
[0012] It is a further object of the present invention to improve the aging property and heat resistance of the sealant composition without affecting its sealing performance.
[0013] It is an object of the present invention to improve the flow ability of the sealant composition through the orifice ensuring better seal ability of material during running condition of tire.
[0014] It is yet another object of the present invention to enhance the aesthetic look and feel of the composition by imparting color to the sealant composition.
SUMMARY OF THE INVENTION
[0015] According to the present disclosure, there is provided a sealant composition overcoming one or more of the problems identified in the prior art characterized in that the composition comprises a isobutylene based polymeric gel, liquid isoprene rubber, rubber component, an antioxidant, tackifier, filler, rubber process oil component, flowing agent and optionally an anti-aging and color imparting agent.
[0016]According to a preferred embodiment of the present invention, the
sealant composition described herein comprises
Atleast about 40-60wt% of an isobutylene based polymeric gel.
Atleast about 10-20wt% of liquid isoprene rubber
Atleast about 30-40wt% of a rubber component

Atleast about 0.1-2wt% of an antioxidant Atleast about 2-15wt% of tackifier Atleast about 20-40wt% of precipitated silica Atleast about 15-30wt% of rubber process oil Atleast about 0.5-3wt% of flowing agent
[0017]The sealant composition prepared from the aforesaid mixture of ingredients are distinguished from and novel over any of the conventional sealant mixtures known hereto. The mixture of ingredients described herein confer a functionally integrated effect of improved sealing performance, higher tackiness at the same time being more environmentally safe, durable and easier to handle than the sealant compositions conventionally available.
[0018] Advantageously, the composition of the present invention is free of solvent, fibrous material and/or crosslinking agent and is devoid of the disadvantages of associated with their inclusion. In a further embodiment, the sealant composition has excellent puncture sealing property without affecting the riding and handling experience of vehicle.
[0019] An aspect of the present invention relates to a process for the
preparation of a tire sealant composition comprising three step mixing of
components in a two-roll mill, wherein:
Step a) comprises mixing of the rubber component(s), and additives,
Step b) comprises blending of the mix obtained in step a) with a filler,
precipitated silica and processing oil, and
Step c) comprises blending of the mix obtained in step b) with a tackifier.
[0020] Yet another aspect of the present invention comprises pneumatic tubeless tires comprising the sealant composition of the present invention.

[0021] Other features and advantages of the present invention will become apparent as the following detailed description proceeds or may be learned by practice of the invention. The advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the description. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0022] For the purposes of the following detailed description, it is to be understood that the invention may assume various alternative variations and step sequences, except where expressly specified to the contrary. Moreover, other than in any operating examples, or where otherwise indicated, all numbers expressing, for example, quantities of ingredients used in the specification are to be understood as being modified in all instances by the term "about". It is noted that, unless otherwise stated, all percentages given in this specification and appended claims refer to percentages by weight of the total composition and the recitation of all numerical ranges by endpoints is meant to include the endpoints of the range, all numbers subsumed within the range and any range within the stated range.
[0023] Thus, before describing the present invention in detail, it is to be understood that this invention is not limited to particularly exemplified systems or process parameters that may of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments of the invention only, and is not intended to limit the scope of the invention in any manner.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the case of conflict, the present document, including definitions will control.
[0025] It must be noted that, as used in this specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the content clearly dictates otherwise. Thus, for example, reference to a “polymer” may include two or more such polymers.
[0026] The terms “preferred” and “preferably” refer to embodiments of the invention that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the invention.
[0027] As used herein, the terms “comprising” “including,” “having,” “containing,” “involving,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to.
[0028] References herein to “one embodiment”, “one aspect” or “one version” of the invention include one or more such embodiment, aspect or version, unless the context clearly dictates otherwise.
[0029] The following definitions are used in connection with the present application unless the context indicates otherwise. As used herein,

[0030] The term “aging” refers to deterioration of physical and chemical properties by oxidation over a period of time.
[0031] The term “antioxidant” refers to a chemical used to retard deterioration specifically caused by oxygen.
[0032] The term “filler” refers to a solid compounding material which may be added, usually in finely divided form, in relatively large proportions, to a polymer.
[0033] The term “Synthetic Rubber” refers to a rubber that is obtained by polymerizing petrochemical based monomers.
[0034] The term “valve” refers to a device used to admit, retain, check or exhaust air in a tube or mounted tubeless tire.
[0035] The term “Pneumatic Tire” refers to an air filled tube or tubeless tire. By the term "Puncture" there is meant any aperture in the tire which results in undesirable air-leakage from within the tire, such as one caused by puncturing, tire failure or inflation-valve failure.
[0036] Further, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains.
[0037] An improved tire sealant composition according to the present invention includes atleast one isobutylene based polymeric gel, liquid isoprene rubber, rubber component, tackifier and filler. Other optional

additives are included to improve the aesthetic appearance, environmental friendliness, viscosity, corrosion potential and the like. Still further additives such as additives for pH adjustment, dispersants, thickening agents, etc may be added to the composition of the present invention to alter the properties based on the requirement.
[0038] The major ingredients of the sealant composition of the present invention are the isobutylene based polymeric gel, liquid isoprene rubber, rubber component, tackifier, filler and the oil component. To these major components are added relatively small amounts of an antioxidant, anti-degrader, and a flowing agent all of which ingredients or equivalents or substitutes thereof are important to result in a composition having the properties desired to achieve the objects of the present invention.
[0039] The isobutylene based polymeric gel forms the primary blocking agent and constitutes about 40 to 60% by weight to the total weight of the sealant composition. Without being bound to any theory it has been found that increasing the isobutylene content enhances the air permeability of the sealed puncture since isobutylene has high air permeability which in turn leads to decrease in air loss of the sealed puncture.
[0040] Liquid isoprene rubber also forms a significant component of the sealant composition constituting 10-20% by weight to the total weight of the sealant composition. The employment of liquid isoprene in the aforesaid constitution has been unexpectedly found to impart high tackiness with the inner lining of the tire which reduces shrinkage and separation of the sealant from the tire.

[0041] The rubber component which can be used for the purposes of the present invention may be synthetic rubbers selected from polybutylene, isobutylene, low molecular weight polyisoprene, polybutylene, isoprene rubber, a styrene-butadiene copolymer rubber, a butadiene rubber and a styrene-isoprene, copolymer rubber or their mixtures. Suitably, the percentage of the rubber component may range from 1 to 60 percent, or from 1 to 50 percent by weight to the total weight of the sealant composition. Most preferably, sealant composition will generally include from about 30 to 40 percent by weight of the rubber component.
[0042] Tackifier is required to provide some "tack" characteristic to the compositions of the present invention. Tackifiers aid in improving the effective preparation by increasing the stickiness of the surface to provide the composition with high initial adhesivity and softness. Suitable tackifiers which can be used for the purposes of the present invention include, but are not limited to terpene resins, petroleum resins, hydrogenated rosins, rosin glycerides, rosin emulsion, hydrogenated rosin glycerides, rosin pentaerythritol aliphatic, terpene phenol resin, a hydrogenated petroleum resin or a mixture of two or more. In a preferred embodiment, the tackifier is selected from terpin resin, phenol resin, rosin resin, petroleum resin, or phenol formaldehyde resin. Suitably, 1 to 20 percent by weight of a tackifier corresponding to the total weight of the sealant composition may be present. According to a preferred embodiment of the invention, amount of tackifier employed is 2-15 percent by weight corresponding to the total weight of the sealant composition.
[0043] In order to stabilize shaping, processing oil such as naphthenic oil or aromatic oil or their mixtures may be employed in the composition. Various other oils which are compatible with the rubber component may be used.

Representative of such oils are paraffinic, naphthenic, aromatic, pine tar and synthetic oils. In a preferred embodiment, the processing oil is naphthenic oil. Typical amount of oil which may be used for the purposes of the present invention may be in the range of 15 to 30 percentage by weight to the total weight of the sealant composition.
[0044] The amount of a filler to be used in the present invention is in the range of from 20 to 40 percentage by weight, or from percentage by weight to the total weight of the sealant composition. In a specific embodiment, the filler is employed in the present sealant composition is precipitated silica. It is has been found that the employment of silica increases the flowability of the composition in comparison to conventionally used fillers such as carbon black. Consequently, the sealing capability of the composition is also enhanced. The sealant composition comprising silica as filler also demonstrates fast sealing and low air loss compared to carbon black. Finally, silica having a high surface area compared to carbon black reduces the ageing effect of the composition.
[0045] Suitable antioxidants which may be used for the purposes of the present invention include amine based antioxidants selected from N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine, N-phenyl-1-naphthylamine, alkylated diphenylamine, octylated diphenylamine, 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, p-(p-toluenesulfony lamido)diphenylamine, N,N'-di-2-naphthyl-p-phenylenediamine, N,N'-diphenyl-p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylenediamine, N-phenyl-N'-(3-methacryloyloxy-2-hydroxy propyl) -p-phenylenediamine, and other aromatic amine compounds. Preferably, the antioxidant employed in the sealant composition of the present invention N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine.

[0046] Preferably the antioxidant is present in the composition in an amount of at least 0.01% by weight, more preferably at least about 0.1% by weight, even more preferably upto about 2% by weight. However, the amounts of antioxidant used can be varied within wide limits in accordance with the intended use of the composition. In some sealant applications the sealant composition of the present invention can be used free of the antioxidant.
[0047] Suitable flowing agents which may be used for the purposes of the present invention include, but are not limited to alkaline earth metal salts such as the carbonate salts and preferably one or more compounds selected from the group consisting of sodium carbonate, magnesium carbonate, calcium carbonate, zinc carbonate, or their combinations thereof. The amount of a flowing agent may be in the range of from 0.5 to 2 percentage by weight to the total weight of the sealant composition.
[0048] According to one embodiment, the sealant composition of the present invention optionally comprises addition of an anti-aging and color imparting agent to the sealant composition. Imparting color to the sealant enables identification of any foreign matter that may have penetrated into the tire.
[0049] In accordance to an advantageous embodiment, the sealant composition of the present invention is free of organic solvents which impart adverse effects to tires. Solvents & solvent vapors when present in sealant composition interact with the inner liner & bead areas of tire and degrade the fabric and rubber compounds used in those areas resulting in damages /loss of strength on inner-liner /bead areas. Also these solvents & solvent vapors are hazardous to human health since they are inflammable

and hence negatively affect safety at work place. Non usage of these organic solvents leads to improvement in tire life, safer processing and handling, and a more environmental friendly composition.
[0050] The various components of the sealant composition of the present invention are believed to be easier to handle and more environmentally safe than many of the ingredients used in making the sealants of the prior art. Advantages achieved by non-employment of cross linking agent and fibrous material are improvement in aging property (more shelf life), stable performance over a time period, easy to remove from tire and recyclable & easy to process. Recyclability and reusability of sealant rubber makes it a completely Green solution with least carbon foot print and economy of operation. The sealant composition of the present invention has excellent puncture sealing properties without affecting riding and handling experience of vehicle.
[0051] Another aspect of the present invention relates to a process for the
preparation of a tire sealant composition comprising a three step mixing of
components in a two-roll mill, wherein:
Step a) comprises mixing of the rubber component(s) and additives,
Step b) comprises blending of the mix obtained in Step a) with the filler and
processing oil, and
Step c) comprises blending of the mix obtained in Step b) with a tackifier.
[0052] Suitably, the components are mixed for about 5 to 30 minutes, or from 5 to 10 minutes at each stage. The mix obtained from Step a) and Step c) are suitably taken out in the form of a sheet.

[0053] The method for applying or injecting the tire puncture sealant of the present invention into the tire is not particularly limited and a conventionally known method can be used. It is highly preferred however that the semi-solid but highly tacky/partially cured sealant material of the present invention be applied like a squeegee. Non-limiting preferred application methods also include extruding/spraying/application in green tire as a sandwich between IL and body ply.
[0054] The sealant composition of the present invention is very safe in terms of bike riding, handling & breaking after applying sealant with excellent puncture sealing and aging properties. After running 3,000 kilometers with two puncture in tire, air loss in sealant applied tire is 3-4 Psi which is similar to loss in normal tire.
[0055] In order to illustrate the invention more clearly, the following examples are given explaining the preferred modes of carrying it into effect and the advantageous results obtained thereby. The use of examples in no way limits the scope and meaning of the invention or of any exemplified term. Likewise, the invention is not limited to various embodiments given in this specification.
EXAMPLES
[0056] The following examples are set forth to further exemplify the invention and are not intended to be limiting thereof.
EXAMPLE 1:
[0057] A preferred sealant composition according to the instant invention
was prepared having the following composition.
The Formulation is as follows:

TABLE 1

Ingredient %wt
Isobutylene based polymeric gel (Primary Blocking agent) 18-50%
5
Liquid Isoprene Rubber 10-20%
Rubber component 15-40%
Antioxidant/Anti fatigue agent 0.1-2%
Tackifier 2-15%
Filler 15-40% 10
Rubber process oil 15-30%
Flowing agent 0.5-3%
Coloring material 3-7%
TABLE 2: 1 Kg of air sealing gel for pneumatic tubeless tires consist of following composition.

Ingredient Components (Grams)
Isobutylene based polymeric gel (Primary Blocking agent) 213.9
Liquid Isoprene Rubber 106.95
Rubber component 213.9
Antioxidant/Antifatgue agent 16.05
Tackifier 53.48
Filler 187.17
Rubber process oil 133.68

Flowing agent 10.7
Coloring material 64.17
TABLE 3: 1 Kg of air sealing gel for pneumatic tubeless tires consist of following Composition.

Ingredient Components (Grams)
Isobutylene based polymeric gel (Primary Blocking agent) 277.78 10
Liquid Isoprene Rubber 111.11
Rubber component 166.67
Antioxidant/Antifatgue agent 16.67
Tackifier 77.77 15
Filler 194.45
Rubber process oil 111.11
Flowing agent 11.11
Coloring material 33.33
20
Preparation of the Sealant composition
The sealant composition was prepared in a two-roll mill which is a machinery traditionally used for mixing rubber compounds. The invention employs a three step mixing in two roll mill wherein in the first stage master batch mixing of the rubber component (a combination of isobutylene based polymeric gel, polyisoprene rubber and Low molecular weight rubber component such as polybutylene), flowing agent (Calcium carbonate or magnesium carbonate or sodium salt of carbonate), antioxidant(N-phenyl-

15

N'-(1,3-dimethylbutyl)-p-phenylenediamine), and anti-degrader(2,2,4-
Trimethyl-1,2-Dihydroquinoline polymer) takes place in the roll-mill for about 5 minutes. The product obtained is taken out as a sheet. Then filler (Silica) and processing oil are added to the sheet and allowed to mix for about 10 minutes. Finally, the tackifier, Phenol formaldehyde resin and natural rosins are added and mixed in the roll-mill for about 10 minutes. Then the coloring material is added and mixed the same in roll mill for 5 minutes. The sealant composition is taken out in sheet form from the roll-mill.
Comparative Example:
[0058] The physical properties and performance of the sealant composition of the present invention was compared with the sealant compositions available in the market. The results are tabulated below.

Type of Sealant Compartive Comparative Using silica as
Sample 1 Sample 2 filler in place of carbon black (present invention) sample 3
Formulation & Isobutylene Isobutylene Isobutylene
Functionality based polymeric based based polymeric
gel polymeric gel gel
10-50% - 10-50% - 18-50% -
Blocking agent Blocking agent Blocking agent
& Reinforcing & Reinforcing & Reinforcing
agent agent agent

Low molecular Low molecular Low molecular
weight weight weight
polyisoprene/po polyisoprene/p polyisoprene/pol
lybutylene- olybutylene- ybutylene-
Tackifier, Tackifier, Tackifier,
viscocity viscocity viscocity
modifier modifier modifier

Process oil Process oil Process oil
0-30% - For 10-20% - For 15-30% - For
processing processing processing
easily & easily & easily &
increase increase increase
elasticity elasticity elasticity

Tackifier Tackifier Tackifier
(phenol (phenol (phenol
formaldehyde formaldehyde formaldehyde
resin ) resin ) resin, wood resin )

Filler Filler Filler
(Combination of (Combination (Combination of
carbon black, of calcium silica, Sodium
Sodium carbonate, carbonate,
carbonate, Sodium sodium Meta
sodium Meta carbonate, silicate, or zinc
silicate, or zinc sodium Meta stearate)
stearate, silicate, or zinc
Spherical cured rubber beads) stearate)

Amine based Antioxidant & Anti degrader. ( (N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediami ne), and 2,2,4-Trimethyl-1,2-Dihydroquinoli ne polymer) Amine based Antioxidant & Anti degrader. ( (N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediami ne), and 2,2,4-Trimethyl-1,2-Dihydroquinoli ne polymer) Amine based Antioxidant & Anti degrader. ( (N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediami ne), and 2,2,4-Trimethyl-1,2-Dihydroquinolin e polymer)

Calcium
carbonate or
magnesium
carbonate or
sodium salt of
carbonate
- Flowing agent
- Calcium
carbonate or
magnesium
carbonate or
sodium salt of
carbonate
- Flowing agent
- Calcium
carbonate or
magnesium
carbonate or
sodium salt of
carbonate
- Flowing agent
-
Application method Extruding / Spraying/Applic ation in cured tyre Extrusion in cured tire on inner liner part Extrusion in cured tire on inner liner part
Physical Observation Sealing property is good but flow ability of material is more Green strength is very low and not able to seal puncture Good shelf life, easy to recycle, safe for processing and

during puncture handling &excellent sealing and tackiness property.
Punture sealing performance A* B* A*
Seal retention performance A# B# A#
Air loss after punctured with nail No air loss Not able to seal No air loss
Air loss after running 3,000 kilometer 4 Psi 14 Psi 2 Psi
Storability A+ C+ A+
* Puncture sealing performance results were expressed on two point scale
A (Sealing) & B (Not sealing)
# Seal retention performance results were expressed on two point scale A
(No air leckage occured) & B (Air leckage occured)
+ After preparing puncture sealant was allowed to stand for 10 days at a temperature of 70 °C., change in state of puncture was visually evaluated. the results were expressed on a three point scale of A (No change, gel form), B(Minor change), C (Unstable)
Inference
As seen in the comparative example, the compositions confers execellent searling and tackiness property. There is an only 2 psi loss in sample 3 after

3,000 km which is very lower compared to comparative samples 1 and 2. It clearly shows that the seal retention strength has increased after aging and it is attributed to the increase in tackiness of material with inner liner and cap of tyre.
[0059] A person skilled in the art will be able to practice the present invention in view of the description presented in this document, which is to be taken as a whole. Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, one of skill in the art will appreciate that certain changes and modifications may be practiced within the scope of the appended claims.

We Claim:
1. A tire sealant composition comprising:
(a) 18-50% of isobutylene based polymeric gel
(b) 10-20% of liquid isoprene rubber
(c) 15-40% of rubber component
(d) 2-15% of a tackifier,
(e)10-30% of a processing oil, and
(f) 15-40% of a filler.
(g) 0.1-2% of Antioxidant
(h) 3-7% of coloring material
2. The composition as claimed in claim 1, wherein the rubber component is selected from polybutylene, isobutylene, low molecular weight polyisoprene, polybutylene, isoprene rubber, a styrene-butadiene copolymer rubber, a butadiene rubber and a styrene-isoprene, copolymer rubber or their mixtures.
3. The composition as claimed in claim 1, wherein the tackifier is selected from phenol resin, formaldehyde resin, wood resin or their combination thereof.

4. The composition as claimed in claim 1, wherein the processing oil is selected from naphthenic oil.
5. The composition as claimed in claim 1, wherein the filler is precipitated silica.

6. The composition as claimed in claim 1, wherein the composition further
comprises an antioxidant, anti-aging and color imparting agent.
7. The composition as claimed in claim 6, wherein the composition comprises 0.1 to 2% of an antioxidant.
8. The composition as claimed in claim 6, wherein the composition comprises 3-7% of an anti-aging and color imparting agent.
9. The composition as claimed in claim 7, wherein the antioxidant is an
amine based antioxidant.
10. The composition as claimed in claim 1, wherein the composition further comprises a flowing agent.
11. The composition as claimed in claim 10, wherein the flowing agent is selected from the group consisting of sodium carbonate, magnesium carbonate, calcium carbonate, zinc carbonate or their combinations thereof.
12. A process for the preparation of a tire sealant composition comprising a
three step mixing of components in a two-roll mill, wherein:
Step a) comprises mixing of the rubber component(s), and other optional
additives,
Step b) comprises blending of the mix obtained in Step a) with the filler and
processing oil, and
Step c) comprises blending of the mix obtained in Step b) with a tackifier.

13. A pneumatic tubeless tire comprising the sealant composition as claimed in claim 1.