WO2019030716A1

WO2019030716A1 - A process of preparing a sealant composition

Info

Publication number: WO2019030716A1
Application number: PCT/IB2018/056036
Authority: WO
Inventors: Gaurav Manik; Nityanshu Kumar; Shubham Mireja; Alok Kumar Yadav
Original assignee: Deniar Trading India Llp; Indian Institute Of Technology Roorkee
Priority date: 2017-08-10
Filing date: 2018-08-10
Publication date: 2019-02-14

Abstract

A process (100) of preparing a sealant composition, comprises the steps of adding (110) an anti-freezing agent in a beaker, mixing (120) a thickening agent with the anti-freezing agent to form a first mixture, mixing (130) water in the first mixture to form a second mixture, adding (140) a plurality of fibrous material is added in the second mixture to form a third mixture. Further, adding (150) an adhesive in the third mixture to form a fourth mixture. Further, adding (160) a plurality of additives, sodium chloride (NaCl), an antioxidant, an anti-skinning agent, colorant, anti-fungal agent and fragrant in the fourth mixture followed by continuous stirring to form the sealant composition.

Description

A PROCESS OF PREPARING A SEALANT COMPOSITION

FIELD OF THE INVENTION

The invention relates to the field of puncture sealing agent for tires and more particularly to a process of preparing a sealant composition. BACKGROUND OF THE INVENTION

Broadly, sealant is a substance used to block the passage of fluids through the surface or joints or openings in materials. Advances in the automotive industry are the development of pneumatic tire sealants to prevent punctures before they occur.

Currently available pneumatic tires are designed to perform for relatively long periods of time. In many cases, automobile tires are expected to have a useful service life of 30,000, 50,000 or 70,000 miles. However, even long-life pneumatic tires are subject to failure due to puncture by nails and other sharp objects.

The concept of a pneumatic tire with puncture sealing properties is old and many attempts to obtain a satisfactory puncture sealing pneumatic tire have been made. Historically, such attempts have entailed modifying pneumatic tires in such a way to retard or prevent a loss of air and consequential deflation of the tire after being punctured with a sharp object, such as a nail.

Prior tire sealant mixtures of the type that may be applied through a valve stem opening have traditionally been used only in Schrader-type valves, i.e., those having a spring-biased valve core that can be completely removed from the valve air inlet opening by unthreading the core from the threaded interior of the valve stem where it is seated.

There have been a number of solutions and methods provided for making composition sealing of the punctured pneumatic tires. Few of them have been discussed below:

GB2370574 (A) describes a method for manufacture to tyre puncture sealant. The method comprises the steps of adding ingredients to primary vessel followed by through stirring and then adding remaining ingredients to secondary vessel. Further, the method includes combining ingredients of first and second vessel and agitating the contents for 30 mins.

US7868061 B2 describes a method for the preparation puncture sealing agent for tire by using glycerin at high concentration. The process produces composition, which suppress the generation of agitation lumps.

The aforesaid documents and similar disclosures which talk about several methods for preparation of pneumatic tire sealant composition comprises number of shortcomings and drawbacks such as, but not limited to, limitation to, the use of fluid puncture sealant coatings which seal by flowing into the hole created by a puncturing object has sometimes been unsuccessful primarily because sealant coatings may flow excessively and thus tend to cause the tire to become out of balance. In addition, many times such a sealant coating is not operable or effective over a wide temperature range extending from summer to winter conditions. Central cores of cellular material, which will physically maintain the shape of the tire when punctured, can place a restriction on the maximum speed of a vehicle on which they are used because of potential breakdown or destruction of the cells caused by the effects of heat and distortion. More complicated structures wherein the sealant material is encased in a vulcanized material are usually expensive to manufacture and can create balance and suspension problems due to the additional weight required in the tire.

A major problem exists with these compositions in that they contain ingredients, which are potentially very hazardous to human health. Additionally, the butyl rubber-containing sealants are typically sprayed into a fixed position on the outer tire wall, but inner tubes cannot receive the sealants in this manner.

Accordingly, there remains a need in the prior art to have an improved process of preparing a sealant composition which is non-toxic, has long shelf life and high sealing ability.

However, there remains a need in the art for a process of preparing a sealant composition. The proposed process provides a composition which is non-toxic and is more effective in self-sealing of punctured tires. Further, the method is easy and which assists in cost saving.

OBJECT OF THE INVENTION

It is an object of the present invention to provide a process of preparing a sealant composition which is non-toxic, non-corrosive, non-flammable, non-aerosol, possess high tensile strength, stability and sealing capabilities.

Another object of the present invention is to provide a process of preparing a sealant composition, which is potential cost saver and user friendly. Another object of the present invention is to provide a process of preparing a sealant composition, which possess anti-sagging property.

SUMMARY OF THE INVENTION

Embodiments of the present invention aim to provide a process of preparing a sealant composition for self-repairing and puncture resistant tires, less toxic, has improved sealing capabilities and assists in cost saving to a great extent. Moreover, many of the processes for the preparation of sealant compositions are expensive and require stringent conditions for preparation. Hence, there is a need to find alternative process of preparing sealant composition, which is highly effective, low cost and produces non-toxic composition with longer shelf life. According to an embodiment of the present invention, the process of preparing a sealant composition comprising the steps of providing an anti-freezing agent, mixing a thickening agent with the anti-freezing agent to form a first mixture, mixing water in the first mixture to form a second mixture, adding a plurality of fibrous material in the second mixture to form a third mixture, adding an adhesive material in the third mixture to form a fourth mixture, adding a plurality of additives, sodium chloride (NaCI), an antioxidant, an anti-skinning agent, colorant, anti-fungal agent and fragrant in the fourth mixture followed by continuous stirring to form the sealant composition.

According to an embodiment of the present invention, the anti-freezing agent is selected from the group consisting of, but not limited to, ethylene glycol, propylene glycol, polyethylene glycol and polypropylene glycol.

In accordance with an exemplary embodiment of the present invention, the anti-freezing agent is present in an amount of, but not limited to, 27% - 33% by weight.

In accordance with an exemplary embodiment of the present invention, the thickening agent is present in an amount of upto, but not limited to, 2% by weight.

According to an embodiment of the present invention, the thickening agent is, but not limited to, xanthum gum (XG) and cross-linked carboxymethyl cellulose (CMC). According to an embodiment of the present invention, the plurality of fibrous materials are selected from, but not limited to, group consisting of cellulose, wool, nylon, rayon, hair, wollastonite, rock wool, glass wool fibers, polyester, carbon fibers and polypropylene. According to an embodiment of the present invention, the carbon fibers having a predetermined length is present in an amount ranging from, but not limited to, 2% - 5% by weight. Further, the length of the carbon fibers is ranging from, but not limited to, 3 mm - 6 mm. Subsequently, the plurality of fibrous materials are stirred for 60 minutes.

According to an embodiment of the present invention, the adhesive material is, but not limited to, ethylene-vinyl acetate (EVA) based polyvinyl acetate emulsion (PAE).

According to an embodiment of the present invention, the plurality of additives are solid additives.

According to an embodiment of the present invention, the plurality of additives are selected from a group consisting of, but not limited to, a plurality of anti-sagging agents, potash alum, mica, and rubber crumb.

In accordance with an exemplary embodiment of the present invention, the sodium chloride (NaCI) is present in a range of 0.4-5% by weight.

According to an embodiment of the present invention, the plurality of anti-sagging agents are selected from a group consisting of, but not limited to, ceramic microspheres.

According to an embodiment of the present invention, the rubber crumb is having a size in range of, but not limited to, 800 micron - 1400 micron.

In accordance with an exemplary embodiment of the present invention, the antioxidant is selected from a group consisting of, but not limited to, phosphoric acid and triethanol amine. In accordance with an exemplary embodiment of the present invention, the sealant composition has a viscosity in a range of, but not limited to, 2200-3300 cP at room temperature of 25°C and at 20 rpm.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the present invention can be understood in detail, a more particular to the description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawing. It is to be noted, however, that the appended drawing illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, the invention may admit to other equally effective embodiments.

These and other features, benefits and advantages of the present invention will become apparent by reference to the following text figure, with like reference numbers referring to like structures across the views, wherein:

Fig. 1 illustrates a process of preparing a sealant composition in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

The present invention is described hereinafter by various embodiments with reference to the accompanying drawing, wherein reference numerals used in the accompanying drawing correspond to the like elements throughout the description. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein. Rather, the embodiment is provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. In the following detailed description, numeric values and ranges are provided for various aspects of the implementations described. These values and ranges are to be treated as examples only, and are not intended to limit the scope of the claims. In addition, a number of materials are identified as suitable for various facets of the implementations. These materials are to be treated as exemplary, and are not intended to limit the scope of the invention. As used throughout this description, the word "may" is used in a permissive sense (i.e. meaning having the potential to), rather than the mandatory sense (i.e. meaning must). Further, the words "a" or "an" means "at least one" and the word "plurality" means "one or more" unless otherwise mentioned. Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope. Language such as "including", "comprising", "having", "containing", or "involving" and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers or steps. Likewise, the term "comprising" is considered synonymous with the terms "including" or "containing" for applicable legal purposes. Any discussion of documents, acts, materials, devices, articles and the likes are included in the specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention.

In this disclosure, whenever an element or a group of elements is preceded with the transitional phrase "comprising", it is understood that we also contemplate the same composition, element or group of elements with transitional phrases "consisting of", "consisting", "selected from the group of consisting of", "including", or "is" preceding the recitation of the composition, element or group of elements and vice versa. Figure 1 is a flow chart illustrating a process (100) of preparing a sealant composition in accordance with an embodiment of the present invention.

At step 110, as shown in figure 1 , an anti-freezing agent is provided in a beaker. Further, the anti-freezing agent is selected from the group consisting of, but not limited to, ethylene glycol, propylene glycol, polyethylene glycol and polypropylene glycol. The anti-freezing agent is present in an amount of, but not limited to, 27% - 33% by weight.

In accordance to an embodiment of the present invention, the anti-freezing agent is stirred continuously on overhead stirrer at 1400-2000 rpm (rotation per minute).

At step 120, mixing a thickening agent with the anti-freezing agent to form a first mixture. Further, the thickening agent used is, but not limited to, xanthum gum (XG) and cross-linked carboxymethyl cellulose. Further, the thickening agent is present in an amount of upto, but not limited to, 2% by weight. Further, the thickening agent provides a uniform viscosity to the sealant composition for its flow within the tire during normal running of vehicle and specifically, during the time of puncture of the tire. At step 130, water is mixed in the first mixture to form a second mixture.

At step 140, a plurality of fibrous material is added in the second mixture to form a third mixture.

In accordance to an embodiment of the present invention, the plurality of fibrous materials are selected from a group consisting of, but not limited to, cellulose, wool, nylon, rayon, hair, wollastonite, rock wool, glass wool fibers, polyester, carbon fibers and polypropylene. Further, defibrillation of carbon fibers is performed to make a fiber network for reinforcing beads. Also, defibrillation of carbon fibers is done until viscosity is attained in the range of ~2,200 to 3,300 cP. Further, the fibrous materials such as carbon fibers provide a high flexural strength to the composition and reduces air exit from the tire during puncture. The carbon fibers used possess a length in range of, but not limited to 3 mm - 6 mm and it is present in an amount ranging from, but not limited to, 2% -5% by weight.

At step 150, an adhesive material is added in the third mixture to form a fourth mixture.

In accordance to an embodiment of the present invention, the adhesive material is, but not limited to, ethylene-vinyl acetate (EVA) based polyvinyl acetate emulsion (PAE). Further, the adhesive material provides adequate adhesion of the sealant components with the tire lining before and during the tire puncture. Further, the adhesive material is present in an amount of, but not limited to, 27% - 33% by weight. At step 160, adding a plurality of additives, sodium chloride (NaCI), an antioxidant, an anti-skinning agent, colorant, anti-fungal agent and fragrant in the fourth mixture followed by continuous stirring to form the sealant composition.

In accordance to an embodiment of the present invention, the antioxidant is selected from a group consisting of, but not limited to, phosphoric acid and triethanol amine. Further, the antioxidant is used in an amount upto, but not limited to, 1 % by weight.

In accordance with an exemplary embodiment of the present invention, the plurality of additives is selected from a group consisting of, but not limited to, a plurality of anti-sagging agents, mica, potash alum and rubber crumb. Further, the rubber crumb is having a size in a range of, but not limited to, 800 micron - 1400 micron and mica is having particle size of upto, but not limited to, 60 microns. Also, the rubber crumb acts as a blocking agent while the hole in tire is open during puncture. Further, the plurality of anti-sagging agents are selected from a group consisting of, but not limited to, ceramic microspheres. The ceramic microspheres help the sealant composition to line the tire even after the vehicle is stopped. Further, the ceramic microspheres also partially help to reduce friction at the sealant tire interface due to easy rolling and supports blocking. In accordance with an exemplary embodiment of the present invention, the sodium chloride (NaCI) is present in a range of 0.4-5% by weight. In accordance with an embodiment of the present invention, the sealant composition is prepared at constant stirring of, but not limited to, 1400-2000 rpm (rotation per minute).

According to another embodiment of the present invention, the tire sealant composition has the capability to completely block a hole created by a puncturing object having diameter upto 9.5 mm, with partial air loss, retaining almost 75% - 100% air in the tire. The puncturing object is selected from a group consisting of, but not limited to, a nail, a screw, a thorn, a pin, a railroad spike and a glass piece.

Further, the sealant composition has a viscosity in a range of 2200-3300 cP at room temperature of 25°C and at 20 rpm.

Hereinafter, non-limiting examples of the present invention will be provided for more detailed explanation, which is not meant to limit the scope of the invention in any manner.

Examples Example 1

1 . Proposed process of preparing a sealant composition for making a 400 gm Batch (at constant rpm of 1000).

Ethylene glycol was taken in a 500ml beaker being stirred continuously with stirrer, in particular overhead stirrer, at 1400-2000 rpm (rotation per minute). Xanthan gum (1 % by weight or as per formulation content) was slowly added into it and mixture is stirred for around 5 minutes. Water was then added followed by stirring mixture for around 5 minutes. Carbon fiber was then added as per formulation content followed by stirring for preferably around 60 minutes as dispersion and partial fibers bundle opening takes time. Polyvinyl acetate emulsion was then added followed by stirring for 5 min. Remaining additives were then added slowly such as NaCI (-0.5 % by weight) followed by potash alum (1 % by weight) and antioxidant (phosphoric acid and triethanol amine in ratio of 1 :5 of about -0.5 % by weight), further followed by addition of ceramic microspheres (from 3M), mica (25-50 micron platelets) (-1 % by weight) and then rubber crumb (-0.8-1 .0% by weight). The formulated viscous liquid was stirred for another 5-10 mins and checked for any possible lumps.

The above mentioned process of preparing as sealant composition overcomes the problems and shortcomings of the existing methods of preparing sealant compositions and provides a number of advantages over them. The sealant composition prepared by the process of the present invention acts as a self-repairing, provides puncture resistant in tires and possess enhanced sealing abilities. Also, the process of the preparation of a sealant composition is easy and cost-effective, as it does not require any expensive techniques. Further tire sealant composition prepared by the process of present invention has the capability to completely block a hole created by a puncturing object having diameter upto 9.5 mm, with partial air loss and still retaining almost 75% - 100% air in the tire. The exemplary implementation described above is illustrated with specific shapes, ingredients, and other characteristics, but the scope of the invention includes various other shapes, ingredients, and characteristics. Also, a process of preparing as sealant composition as described above could be fabricated in various other ways and could include various other materials, including various anti-freezing material, fibrous material, thickening agent and antioxidant.

Various modifications to these embodiments are apparent to those skilled in the art from the description and the accompanying drawings. The principles associated with the various embodiments described herein may be applied to other embodiments. Therefore, the description is not intended to be limited to the embodiments shown along with the accompanying drawings but is to be provided broadest scope consistent with the principles and the novel and inventive features disclosed or suggested herein. Accordingly, the invention is anticipated to hold on to all other such alternatives, modifications, and variations that fall within the scope of the present invention and appended claims.

Claims

We Claim:

1 . A process (100) of preparing a sealant composition, comprising the steps of: providing (11 0) an anti-freezing agent; mixing (120) a thickening agent with the anti-freezing agent to form a first mixture; mixing (130) water in the first mixture to form a second mixture; adding (140) a plurality of fibrous material in the second mixture to form a third mixture; adding (150) an adhesive agent in the third mixture to form a fourth mixture; adding a plurality of additives, sodium chloride (NaCI), an antioxidant, an anti-skinning agent, colorant, anti-fungal agent and fragrant in the fourth mixture followed by continuous stirring to form the sealant composition.

2. The process(100) as claimed in claim 1 , wherein the anti-freezing agent is selected from the group consisting of, ethylene glycol, propylene glycol, polyethylene glycol and polypropylene glycol.

The process (100) as claimed in claim 2, wherein the anti-freezing agent is present in an amount of 27% - 33% by weight.

The process as claimed in claim 1 , wherein the thickening agent is present in an amount of upto 2% by weight.

The process (100) as claimed in claim 4 wherein the thickening agent is xanthum gum (XG) and cross-linked carboxymethyl cellulose (CMC).

6. The process (100) as claimed in claim 1 , wherein the plurality of fibrous materials are selected from a group consisting of, cellulose, wool, nylon, rayon, hair, wollastonite, rock wool, glass wool fibers, polyester, carbon fibers and polypropylene.

7. The process (100) as claimed in claim 6, wherein the carbon fibers having a predetermined length is present in an amount ranging from 2% -5% by weight.

8. The process (100) as claimed in claim 7, wherein the length of the carbon fibers is ranging from 3 mm - 6 mm.

9. The process (100) as claimed in claim 6, wherein the plurality of fibrous materials are stirred for 60 minutes.

10. The process (100) as claimed in claim 1 , wherein the adhesive material is ethylene-vinyl acetate (EVA) based polyvinyl acetate emulsion (PAE).

1 1 . The process (100) as claimed in claim 1 , wherein the plurality of additives are solid additives.

12. The process (100) as claimed in claim 1 , wherein the plurality of additives are selected from a group consisting of, a plurality of anti-sagging agents, mica, potash alum and rubber crumb.

13. The process (100) as claimed in claim 1 , wherein the sodium chloride (NaCI) is present in a range of 0.4-5% by weight.

14. The process (100) as claimed in claim 12, wherein the plurality of anti-sagging agents are selected from a group consisting of ceramic microspheres.

15. The process (100) as claimed in claim 12, wherein the rubber crumb is having a size in a range of 800 micron - 1400 micron.

16. The process (100) as claimed in claim 1 , wherein the antioxidant is selected from a group consisting of, phosphoric acid and triethanol amine.

17. The process (100) as claimed in claim 1 , wherein the sealant composition has a viscosity in a range of 2200-3300 cP at room temperature of 25°C and at 20 rpm.