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, India;
Nationality: India
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] The present application relates to a tire puncture sealant composition for application inside tire to effectively prevent air loss after tire is punctured on road/off road during running. In particular, the present invention relates to a tire puncture sealant composition having a high concentration of rubber and filler. The present invention also relates to a process for the preparation of a tire puncture sealant composition and also to tires comprising the afore-mentioned composition.
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. US20120041099A1 reports a tire puncture sealant comprising a rubber latex and/or a resin emulsion, an acetylene alcohol and/or a derivative thereof. EP0798140A2 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 footprint and economy of operation. The process employed for its preparation is environmental friendly, cost effective and easily scalable.

SUMMARY OF THE INVENTION
[0009] The object of the present invention is to provide a tire puncture sealant composition that will materially alleviate the problems associated with the conventional tire sealant compositions as discussed above.
[0010] A sealant composition overcoming one or more of the problems identified in the
prior art is provided comprising:
60-95% of rubber;
5-25 % carbon black; and
1-15% processing oil.
[0011] 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.
[0012] 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 60-95% of the rubber component;
Step b) comprises blending of the mix obtained in Step a) with 5-25 % carbon black and 1-15% processing oil; and Step c) comprises optionally adding other ingredients to the mix obtained in Step b).
[0013] Another aspect of the present invention relates to a process for the preparation of a tire sealant composition comprising a continuous mixing of components in a twin-screw extruder wherein all the materials are mixed at the same time.
[0014] Yet another aspect of the present invention relates to tires such as but not limited to pneumatic tube or pneumatic tubeless tires comprising the sealant composition of the present invention.

[0015] 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
[0016] 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.
[0017] 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.
[0018] 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.
[0019] 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.

[0020] 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.
[0021] 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.
[0022] 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.
[0023] The following definitions are used in connection with the present application unless the context indicates otherwise. As used herein,
[0024] The term “aging” refers to deterioration of physical and chemical properties by oxidation over a period of time.
[0025] The term “antioxidant” refers to a chemical used to retard deterioration specifically caused by oxygen.
[0026] The term “carbon black” refers to a material used in tires that provides strength to rubber compounds. This material consists essentially of elemental carbon in the form of near spherical colloidal particles and aggregates. Carbon black is obtained by partial combustion or thermal decomposition of hydrocarbons.
[0027] 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.
[0028] The term “synthetic rubber” refers to a rubber that is obtained by polymerizing petrochemical based monomers. The term “crumb rubber” is the name given to any material

derived by reducing scrap tire or other rubber into uniform granules with the inherent reinforcing materials such as steel and fiber removed along with any other type of inert contaminants such as dust, glass, or rock. It is fine granular or powdered rubber capable of being used to make a variety of products. It is recovered from scrap tires using thermal or mechanical processing techniques. A variety of methods may be employed, including grinding at low temperatures (i.e., cryo-grinding). Crumb rubber also is derived from the tire retreading process, when worn tire tread is removed during a buffing process before the new tread is affixed.
[0029] The term “valve” refers to a device used to admit, retain, check or exhaust air in a tube or mounted tubeless tire.
[0030] 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.
[0031] 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.
[0032] In an embodiment, the present invention relates to a tire puncture sealant composition
comprising:
60-95% of rubber;
5-25 % carbon black; and
1-15% processing oil.
[0033] The major ingredients of the sealant composition of the present invention are the rubber, carbon black as a filler and the oil component. To these major components are added relatively small amounts of optional ingredients or additives (such as 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. Various other additives such as additives for pH adjustment, dispersants, thickening agents, anti-ozonants, anti-static materials, adhesion promoters,

additives to prevent wire corrosion may be added to the composition of the present invention to alter the properties based on the requirement.
[0034] The rubber which can be used for the purposes of the present invention may be synthetic rubbers selected from polybutylene, isobutylene, polyisobutylene, cross link butyl rubber, 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 60 to 95 percent, or from 60 to 85 percent by weight to the total weight of the sealant composition. Most preferably, sealant composition will generally include from about 40 to 45 percent by weight of cross link butyl rubber and 40 to 45 percent by weight of Polyisobutylene. A higher percentage of the rubber is added in the composition in order to improve the elastic and flow property of sealant so that seal ability is maintained while running the tire with nail inside.
[0035] A long-standing problem whenever a sealant gel formulation is applied on the surface of inner-liner of a tire is sealant dislocation which is a phenomenon where the sealant accumulates at the center of the tire due to the said forces operate in the dynamic condition of the tire. This in turn causes unavailability of sealant in the contact patch areas near the shoulder regions. Hence, inefficient puncture filling possibility. Flow of sealant towards the center makes the tire more prone to puncture. This sealant dislocation is due to centrifugal force, profile of tire & flow property of sealant. In an embodiment of the present invention, the sealant dislocation towards center is reduced up to 31% due the composition of the present invention, thereby improving availability of sealant over larger area.
[0036] In an embodiment, the rubber is a blend of cross link butyl rubber and at least a low molecular weight rubber; wherein the low molecular weight rubber is selected from polyisoprene, polybutylene, or an isobutylene or their combinations thereof based polymeric gel in a ratio of about 1:0.5, about 1:1, about 1:1.5 to about 2:1.
[0037] 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. The tackifiers used in the present invention are optional ingredients.
[0038] Suitable tackifiers which can be used for the purposes of the present invention include, but are not limited to wood resin, phenol formaldehyde resin, hydrocarbon resin, cumorene indene resin or combinations thereof. Suitably, 0 to 10 percent by weight of a tackifier corresponding to the total weight of the sealant composition may be present.
[0039] The composition of the present invention contains from 5 to 25 percentage by weight of carbon black to the total weight of the sealant composition as the filler. Exemplary forms of carbon black preferred in the context of the present invention include Acetylene black, Thermal black, Furnace black or their combinations thereof. Especially preferred is the kind of carbon black known as Furnace black (grades described in ASTM D 1765 employed either individually or in combination with different grades this component).
[0040] 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 1 to 15 percentage by weight to the total weight of the sealant composition.
[0041] An optional filler which may be used in the present invention is zinc stearate. The amount of a filler to be used in the present invention is in the range of from 0 to 5 percentage by weight to the total weight of the sealant composition. In a specific embodiment, the filler may be a combination of carbon black and zinc stearate. The filler may further optionally comprise 0-10 % crumb rubber.
[0042] In an embodiment of the present invention, the sealant composition may optionally comprise an anti-oxidant, an anti-ozonanat, an anti-degrading agent and a flowing agent. Suitable anti-oxidants, anti-ozonanats which may be used for the purposes of the present invention include amine based antioxidants selected from the group consisting of N-phenyl-

1-naphthylamine, alkylated diphenylamine, octylated diphenylamine, 4,4'-
bis(α,αdimethylbenzyl)diphenylamine, p-(p-toluenesulfonylamido)diphenylamine, N,N'-
di-2-naphthyl-p-phenylenediamine, N,N'-diphenyl-p-phenylenediamine, N-phenyl-N'-
isopropyl-p-phenylenediamine, N-phenyl-N'-(1,3-dimethylbutyl)-p-
phenylenediamine,Nphenyl-N'-(3-methacryloyloxy-2-hydroxy propyl)-p-
phenylenediamine, 2,2,4-Trimethyl-1,2-Dihydroquinoline polymer and other aromatic amine compounds.
[0043] Suitable anti-degrading agent which can be used for the purposes of the present invention include, but are not limited to N-phenyl-N'-(1,3-dimethylbutyl)-phenylenediamine, 2,2,4-Trimethyl-1,2-Dihydroquinoline polymer, acetone/diphenylamine condensate, dicyclohexylamine and a nitroso aromatic amine or their combinations thereof.
[0044] 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.
[0045] The various components/ingredients 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.
[0046] 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.

[0047] Another embodiment 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 60-95%of the rubber component; and
Step b) comprises blending of the mix obtained in Step a) with 5-25 % carbon black and 1-15% processing oil; and Step c) comprises optionally adding other ingredients to the mix obtained in Step b).
[0048] 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 b) are suitably taken out in the form of a sheet/dough.
[0049] Another embodiment of the present invention relates to a process for the preparation of a tire sealant composition comprises a continuous mixing of components step a, b and c mentioned above in a twin-screw extruder wherein all the materials are mixed at the same time.
[0050] The components may be added into the mixture in the following manner.
1) Dry Rubber;
2) Powder ingredients other than carbon black;
3) Liquid ingredients; and
4) Carbon black.
[0051] The method for applying or injecting the air sealant gel composition 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 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.

[0052] 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 punctures in tire, air loss in sealant applied tire is 2 Psi which is similar to loss in normal tire.
[0053] 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
[0054] The following examples are set forth to further exemplify the invention and are not intended to be limiting thereof.
EXAMPLE 1:
[0055] A preferred sealant composition according to the instant invention was prepared
having the following composition.
The Formulation is as follows:
TABLE 1

Ingredient Components (% - percentages)
Cross link butyl rubber 60-95
Zinc stearate 0-5
6 PPD (Antiozonant, Antioxidant) 0
TMQ (Antioxidant) 25 0
Oil 1-15
Carbon black 5-25
Crumb rubber 0-10
Poly iso butylene 60-95
Liquid isoprene rubber 60-95 30
Wood Resin 0-10

Representative formulations of TABLE 1
TABLE 2: 1 Kg of air sealing gel for pneumatic tubeless tires consist of following composition.

Ingredient Components (% -percentages)
Cross link butyl rubber 40.8 10
Zinc stearate 1.7
6 PPD (Antiozonant, Antioxidant) 0
TMQ (Antioxidant) 0
Oil 3.11
Carbon black 12.75 15
Crumb rubber 0
Poly iso butylene 41.65
Liquid isoprene rubber 0
Wood Resin 0
Preparation of the sealant composition:
[0056] 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 (a combination of cross link butyl rubber, isobutylene based polymeric gel and low molecular weight polyisoprene/polybutylene), takes place in the roll-mill for about 5 minutes. The product obtained is taken out as a sheet. Then carbon black and processing oil are added to the sheet and allowed to mix for about 10 minutes. Optionally, the tackifier wood resin may be added and mixed in the roll-mill for about 10 minutes. The sealant composition is taken out in sheet form from the roll-mill.

Comparative Example:
[0057] 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.

Formulation & Functionality
Conventional Sealant composition Sealant composition of present invention
Isobutylene based polymeric gel 10-50% - Blocking agent & Reinforcing agent Isobutylene based polymeric gel 35- 50% - Blocking agent & Reinforcing agent
Low molecular weight
polyisoprene/polybutylene- Tackifier, viscosity modifier Low molecular weight
polyisoprene/polybutylene- Tackifier, viscosity modifier (35-60%)
Process oil 0-30% - For processing easily &increase elasticity Process oil 1-10% - For processing easily &increase elasticity
Tackifier (phenol formaldehyde resin) -
Filler (Combination of carbon black, Sodium carbonate, Sodium meta silicate, or zinc stearate, Spherical cured rubber beads) Filler (Combination of carbon black, and zinc stearate, )
Amine based antioxidant & anti degrader. ( (N-phenyl-N'-(1,3-dimethylbutyl)-phenylenediamine),and 2,2,4-Trimethyl-1,2-Dihydroquinolin -
Calcium carbonate or magnesium carbonate or sodium salt of carbonate - Flowing agent - -

TEST RESULTS
Physical Observation Good shelf life, easy to recycle, safe for processing and handling &excellent sealing property. Good shelf life, easy to recycle, safe for processing and handling &excellent sealing property.
Puncture
sealing
performance A A
Seal retention performance A# A#

Air loss after No air loss No air loss
punctured
with nail
Air loss after 3 psi 2 psi
running 3,000
kilometer
Storability A+ A+
Air loss after
running 200
kilometer with B# A#
nail up to 2.5 mm

inside tire
Dislocation of 16 mm 5mm
sealant material
(High speed
Indoor test: With
load of 128 daN )
Sealant
separation due to
affinity towards
water
(Hygroscopic
nature, during
tire mounting High Nil
soap solution is
applied which
interact with
sealant and leads
to seperation of
sealant from tire)
Remarks :
1. 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 sealant composition 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)

IMPROVED TEST CONDITIONS
Before After
1) At every 300 Km run 3 punctures 1) At every 300 Km run 3 punctures
done with 2.5 mm nail and nail done with 2.5 mm nail and nail
removed immediately from tire, then removed immediately from tire, then
vehicle was allowed to run for further vehicle was allowed to run for further
300 km and air loss measured 300 km and air loss measured
Results: 3 or less than 3 psi Results: 2 or less than 2 psi
2) Tire punctured with 3.5 mm nail 2) Tire punctured with 3.5 mm nail
and kept in static condition for 3 days and kept in static condition for 3 days
and air loss measured and air loss measured
Results: 3 or less than 3 psi Results: 2 or less than 2 psi
3) Sealant composition was allowed to 3) Sealant composition was allowed
stand for 10 days at a temperature of to stand for 10 days at a temperature of
70 °C., change in state of puncture was 70 °C., change in state of puncture was
visually evaluated. visually evaluated.
Results: No change Results: No change
4)No such test done earlier 4)Water resistant test :
Tire mounted in rim filled with 20 ml
Results: Sealant separation happened of water, then it will run for 4 cycle
indoor test (Cycle detail : Run at
20km/hr for half hour and kept hour
ideal then again same)
Results : No impact on sealant
5) No such test done earlier 5) 1.5 mm 2 nails & 2.5 mm 2 nails
punch inside tire and vehicle run for
Results: Leakages observed 220 KM run. After that nails are
removed and run for 100 KM.
Results: Air loss less 2 or less than 2 psi.
5) No such test done earlier 6) High speed indoor test
Results: Minimum 15 mm shrinkage of Results: Shrinkage of sealant 5mm
sealant max

[0058] 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 puncture sealant composition comprising:
60-95% of rubber;
5-25 % carbon black; and 1-15% processing oil.
2) The composition as claimed in claim 1, wherein the rubber is selected from polybutylene, isobutylene, polyisobutylene, low molecular weight polyisoprene, isoprene rubber, a styrene-butadiene copolymer rubber, a butadiene rubber and a styrene-isoprene, cross link butyl rubber, copolymer rubber or their mixtures.
3) The composition as claimed in claim 1, wherein the rubber is a blend of cross link butyl rubber and at least one low molecular weight rubber selected from the group consisting of polyisoprene, polybutylene, an isobutylene based polymeric gel or combinations.
4) The composition as claimed in claim 3, wherein the cross link butyl rubber and at least one low molecular weight rubber are present in in a ratio of about 1:0.5, about 1:1, about 1:1.5 to about 2:1.
5) The composition as claimed in claim 1, wherein the composition optionally has 0-10% tackifier and said tackifier is selected from the group consisting of wood resin, phenol formaldehyde resin, hydrocarbon resin, cumorene indene resin or combinations thereof.

6) The composition as claimed in claim 1, wherein the processing oil is naphthenic oil, paraffinic oil, aromatic oil, pine tar oil, synthetic oils or their mixtures.
7) The composition as claimed in claim 1, wherein the composition optionally comprises 0 to 5% zinc stearate or 0-10 % crumb rubber as fillers.
8) The composition as claimed in claim 1, wherein the composition optionally comprises an anti-oxidant, an anti-ozonant, an anti-degrader or a flowing agent.

9) A process for the preparation of a tire puncture sealant composition as claimed in claim
1 comprising a three-step mixing of components in a two-roll mill, wherein:
Step a) comprises mixing 60-95%of the rubber component; and
Step b) comprises blending of the mix obtained in Step a) with 5-25 % carbon black and 1-15% processing oil; and Step c) comprises optionally adding other ingredients to the mix obtained in Step b).
10) The process as claimed in claim 8, wherein said process comprises a continuous mixing of components of step a, b and c in a twin-screw extruder wherein all the materials are mixed at the same time
11) A tire comprising the sealant composition as claimed in claim 1.