WO2008022402A1

WO2008022402A1 - Improved sealing composition

Info

Publication number: WO2008022402A1
Application number: PCT/AU2007/001222
Authority: WO
Inventors: Terence Dowel
Original assignee: Trydel Research Pty Ltd
Current assignee: Trydel Research Pty Ltd
Priority date: 2006-08-25
Filing date: 2007-08-24
Publication date: 2008-02-28
Anticipated expiration: 2009-02-25

Abstract

A sealing composition for the sealing, as by repair, of a damaged inflatable article, as for example the tyre of a vehicle, includes a liquid carrier, one or more viscosity and suspending agents, one or more fillers and sealants, and one or more corrosion inhibitors.

Description

IMPROVED SEALING COMPOSITION

FIELD OF INVENTION

The present invention relates, in general terms, to a composition for use in the sealing of a damaged inflatable article. More particularly, but not exclusively, the invention relates to an improved composition for use in the sealing of a damaged - as for example punctured - tyre for a vehicle. The invention further relates to an apparatus for use in the application of such a sealing composition to (into) a damaged tyre and for inflating such tyre to a pressure suited for use. The invention also relates to a method for the preparation of such a composition. BACKGROUND OF THE INVENTION

A puncture can be a serious hazard associated with the use of inflatable load-carrying articles such as tyres - whether such be on automobiles, trucks, motorcycles, bicycles, etc. When a puncture occurs with an automobile, for example, the traditional practice has been to replace the damaged/punctured tyre with the spare, with such spare being intended to allow for use of the vehicle either only for a limited time and limited distance — to allow the driver to travel to a site where the damaged tyre can be repaired and restored to the vehicle - or in the alternative to allow the vehicle to be driven without problems until such time as a replacement or repaired tyre can be secured and installed.

There can be, however, difficulties associated with, firstly, removal of a punctured tyre and, secondly, location of the spare or a replacement tyre on the vehicle. These difficulties can include the unavailability of the tooling needed to remove a damaged tyre and replace such with the spare, and the actual physical effort associated with such tasks, not to mention potential risks/damage to the person effecting such a task. Furthermore, the situation has been known to arise where the spare tyre may not be sufficiently inflated to be properly and safely useable.

In accord with the prior art practices there have been employed, for purposes of introduction of a sealing composition into a punctured tyre, an apparatus consisting of a pressurised container for the sealing composition which houses a liquefied gas - of any suitable type- as a pressure source. Such container includes, for purposes of dispensing the contents thereof, a valve or the like having associated or to be associated therewith an adaptor which allows for connection of the overall container to the tyre valve. Such an adaptor may be of the screw-on type, or of any other known type. With such an arrangement the sealing composition is sprayed into the tyre through the tyre valve, the tyre then being re-inflated by means of the propellant gas, which then allows the car to be driven. In another known arrangement a sealing composition is housed within a compressible flask which is to be connected, via an adaptor of any known type, to the tyre valve, with the valve insert or core having first been removed therefrom. With such an arrangement the sealing composition is sprayed into the tyre by applying pressure to the compressible flask. After the valve core or insert has been replaced, the tyre can then be re-inflated as desired (using any suitable means and method). This method and arrangement suffers in that, to be carried out, it is necessary to physically remove the valve core or insert from the tyre valve itself.

In accordance with the known art there have also been used in the past sealant compositions, intended to be injected into a damaged tyre, useful for emergency (and almost invariably) temporary, repair of a puncture wound in the tread portion of such tyre. Such compositions have traditionally included latex (or the equivalent) as a principal constituent thereof. The compositions are intended to be injected into the tyre via the tyre valve (with or without valve core in place).

However the use of latex (or an equivalent) in itself has given rise to problems, due to the "sticky" nature thereof. Firstly, the use of latex will leave a sticky, messy residue in the tyre valve itself, which will more often than not need to be removed/cleaned away before that valve is re-useable. Secondly, the dispensation of a latex-based composition from a container therefor will mean that such container may not be suitable for re-use, again by reason of the fact that any nozzle or the like dispensing means associated therewith, and/or any tubing or hosing for passage of the sealing composition from container to tyre, will be gummed-up, perhaps even being blocked or sealed, by residual or undispersed composition.

Further, and when a latex-based composition is employed the situation is that, when air is still escaping from the tyre, via the puncture, and the latex composition is oozing (under pressure) through the hole in the tyre, the air causes the latex to cross-link and bond with the rubber of the tyre. The end result is that, whilst the puncture may be sealed, the actual puncture site becomes extremely difficult, if not actually impossible, to locate. This inability to identify a repaired puncture site gives rise to its own problems. In accordance with regulations, and indeed using common sense, if one knows of the existence of a puncture in a tyre, and even if that puncture has been temporarily repaired - using such a latex-based composition - it is still necessary to have the tyre properly, and permanently, repaired. If the site cannot be located, a permanent repair cannot be effected. The alternative, then, is to physically replace the tyre when punctured - an expensive exercise indeed.

There are environmental issues concerning latex and the use of latex- based compositions for purposes of temporary tyre repair which may be summarised as follows:

(1) the life or age limit of latex is usually 5 years;

(2) unless the puncturing object remains in the tyre it is virtually impossible to locate, inspect and repair the tyre permanently - to meet with safety regulations and standards the tyre must then be discarded;

(3) latex must not be allowed to enter sewerage/surface water or ground water;

(4) any used packaging contaminated with cured latex cannot be cleaned for recycling and therefore must be disposed of along with the substance; (5) with latex, cleaning and washing the tyre is problematic; the tyre can only be cleaned by absorbing the liquid with cloth/rags and placing them in containers for waste disposal;

(6) latex emulsion gives off a strong ammonia vapour and is therefore not popular in tyre repair shops and the like, due to this noxious odour;

(7) latex emulsion has a pH value of 10 and, if contact occurs, can cause irritation to eyes, skin or mucous membranes;

(8) latex spills will permanently stain clothing or work garments unless the excess latex is immediately removed and the garments thoroughly washed before cross-linking occurs, which usually is not feasible;

(9) latex sealants ideally should be filled into bottles undera bed of nitrogen to minimise the cross-linking effects of oxygen on latex; any oxidation is detrimental to the sealing capacity of latex and also increases the possibility of granulated particles lodging in tyre valve; even occasional small droplets of latex carried by compressed air (or the like) in hoses can start "skinning" in the hose and can also end up agglomerating in the valve area; and (10) latex contains volatile organic compositions which can be harmful to health if swallowed, cause acid burns, can cause sensitisation through skin contact and are highly toxic for aquatic organisms.

Apart from the problems associated with the prior art as outlined earlier, these days it is a trend in vehicle design that vehicles are now being manufactured and marketed without being supplied with a spare wheel. This means that a practical, workable repair kit needs to be provided, such a kit being intended to be simple to operate, preferably re-useable and not requiring clean-up of excess sticky sealing compounds (as for example latex or the like). The present invention seeks to overcome such problems and difficulties associated with the prior art practices by providing a composition and apparatus which allows for ready repair - as by re-sealing - of a punctured tyre, thereby eliminating the need for replacement thereof (at least temporarily).

With the composition and apparatus of this present invention it is not necessary to remove the valve core or insert from the tyre valve. More importantly with the composition of the present invention, by not including latex (or the equivalent), avoids the need for a difficult clean-up and disposal of residual unwanted material (latex) upon completion of any repair.

It will be understood, by those persons familiar with this art, that punctures which are capable of being effectively sealed with these types of compositions are those which occur in the substantial majority of cases to vehicle wheels in the course of normal usage, as for example, punctures to car and truck tyres by nails, screws, pieces of wire and the like. DESCRIPTION OF THE INVENTION

According to one aspect of the invention, therefore, there is provided a composition for sealing of a punctured tyre which is introducible into the tyre via the tyre valve thereof, without any need to first remove the tyre valve core or insert and without resulting in any blockage of the tyre valve itself and any associated tubing, with the entire composition being capable of passing through the restricted passage existing within the valve. A sealant composition in accordance with the broadest aspect of the present invention includes, as its principal constituents, a liquid carrier, one or more viscosity and suspending agents, one or more fillers and sealants, in the form of particulate material, and one or more corrosion inhibitors. Hereinafter each of these principal constituents will be explained in more detail. A preservative may also be present.

As to the liquid carrier, such may be water, in an amount of from 5 to 95 percent by weight. Alternatively, a mixture of water and propylene glycol and/or ethylene glycol, again in an amount of from 5 to 95 percent by weight, may be employed. In yet a further alternative the liquid carrier may be a mixture of propylene glycol and ethylene glycol, again in an amount of from 10 to 90 percent by weight. The principal requirement of such carrier is that it is substantially inert in terms of its reacting with the other constituents of the overall composition. In an especially preferred embodiment the liquid carrier will be a mixture of up to 30 percent by weight water and up to 30 percent by weight of propylene glycol and/or ethylene glycol.

Insofar as the viscosity and suspension agents are concerned, any one (or more) of the following may be employed:

(a) a polysaccharide gum, as for example Xanthan gum, in an amount of from 0.05 to 1.0 percent by weight, more preferably about 0.25 percent by weight;

(b) carboxymethylcellulose and/or methylhydroxyethylcellulose, in an amount of from 0.01 to 1.0, more preferably about 0.05, percent by weight; and/or

(c) fumed silica (more especially that available under the name/trade mark AEROSIL R972), in an amount of from 0.01 to 1.0, more preferably about 0.05, percent by weight. The fillers or particulates in the composition, whose function is to seal the puncture, may include any one or more of the following:

(a) pulverised bark powder and/or pulverised peanut shells, or the like fibrous or cellulosic material, of a particle size less than 150 micron and in an amount of from 0.01 to 1.0, more preferably about 0.075, percent by weight;

(b) powdered Equisetum Arvense (commonly known as "horsetail"), of a particle size less than 150 micron and in an amount of from 0.01 to 1.0, more preferably about 0.06, percent by weight; (c) tea powder, of a particle size less than 150 micron and in an amount of from 0.01 to 1.0, more preferably about 0.05, percent by weight;

(d) parsley powder, of a particle size less than 150 micron and in an amount of from 0.01 to 1.0, more preferably about 0.05, percent by weight; (e) diatomite, of a particle size less than 30 micron and in an amount of from 0.05 to 5.0, more preferably about 1.5, percent by weight;

(f) Bentonite, of a particle size less than 40 micron and in an amount of from 0.15 to 5.0, more preferably about 0.75, percent by weight;

(g) gum rosin, of a particle size less than 30 micron and in an amount of from 0.05 to 1.5, more preferably about 0.2, percent by weight; and/or (h) titanium dioxide, in an amount of from 0.01 to 1.0, more preferably about 0.10, percent by weight.

Any suitable corrosion inhibitors may be employed. Preferably such may be a combination of one or more of the following:

(a) ammonium carbonate, in an amount of from 0.01 to 1.0, more preferably about 0.06, percent by weight;

(b) sodium bicarbonate, in an amount of from 0.1 to 1.0, more preferably about 0.06, percent by weight; and/or

(c) sodium borate, in an amount of from 0.02 to 2.0 more preferably about 0.12, percent by weight. Experience/experimentation has revealed that, internally of a tyre, corrosive elements/components can exist and/or be formed. By way of example only, traces (minor amounts) of sulphuric acid can be found to leak from a tyre. Furthermore, corrosive elements/components can be created/formed within the tyre chamber itself, as for example traces of ozone generated by static electricity (between for example the tyre bead and the associated wheel/rim).

Such corrosive elements can, with time, have a deleterious effect on any exposed metal of the wheel/rim. For that reason, in an especially preferred embodiment the composition in accordance with the present invention will have included therein one or more corrosive inhibitors. Such will preferably be from the group including ammonium bicarbonate, sodium bicarbonate and/or sodium borate. Ammonium bicarbonate and/or sodium bicarbonate may be included in an amount of from 0.01 to 1.0 per cent, most preferably 0.06 per cent, by weight. Sodium borate may be included in an amount of from 0.02 to 2.0 per cent, most preferably 0.12 per cent by weight.

As can be seen from above the sealing composition in accordance with the present invention is in the form of a stable aqueous suspension of one or more solid particulate materials, wherein the particulate material preferably is a minor amount of the overall composition. The carrier fluid, such as water, or water in combination with propylene glycol and/or ethylene glycol and the minor amounts of one or more solid particulate materials (which are substantially insoluble in the liquid components of the composition) are inert to the rubber composition of the tyre into which it is intended to be placed.

The particulate material making up the "solid" component of the composition may include materials such as vermiculite, diatomaceous earth and other infusorial earths, various forms of mica and other finely divided solids.

Compositions in accordance with the invention achieve their effectiveness - as compared with the latex-based prior art compositions - by virtue of being based on/in the form of a colloidal dispersion blended with other fine particles which is capable of passing through the restrictive passage afforded by a valve core of a tyre valve without resulting in blockage thereof, yet at the same time retains sufficient sealing properties to be capable of repairing punctures.

A preferred suspension medium is a combination of 0.15 to 0.2 percent Xanthan gum and 0.05 to 0.075 percent methyl hydroxyethylcellulose. To allow for prolonged storage in motor vehicles (for as long as 8 years) all solid particles in the formulation must remain substantially in suspension during a test when subjected to 80 degrees Celsius temperature for a period of 12 hours and can easily be redispersed after shaking.

It is important also that there be only minimal separation of ingredients within the tyre chamber when the liquid is subjected to centrifugal force at 80kph. To optimise the suspending properties of Xanthan gum, pH adjustments to the pH of the composition, to a value of about 7.65, are preferred. The preferred alkali ingredients for this adjustment comprise a blend of sodium bicarbonate, ammonium bicarbonate and sodium borate. The ingredients also act as corrosion inhibitors and buffer the acidic attack caused by traces of sulphuric acid leaching from the tyre compound and migrating into the sealant. Coupled to this there are also added corrosive elements from the formation of ozone inside the tyre chamber caused by the static charge generated between the tyre bead and wheel/rim. Due to the highly restricted passage through the valve core the liquid must be formulated in such a way that the sealing particles referenced therein pass freely through the valve unhindered and therefore do not agglomerate anywhere, such as to avoid the possibility of blockage occurring.

The preferred fibre particles suitable for the initial seal is pulverised tree bark powder. It has been found, however, that the bark powder as a blocking medium on its own is too aggressive and will block the valve core almost immediately, even at low levels. For that reason, and to avoid such a possibility, a combination of additional fibres at varying percentages allows some control over how the fibres react when passing through the valve core. Bark fibre requires the addition of another fibre, such as Equisetum

Arvense, that flows through more freely without restriction and, when coupled with bark fibre, orientates and guides the bark fibre through the restricted valve passage, carrying the bark fibre without it in any way adversely effecting the initial sealing action of the bark fibre itself. As a substitute for bark fibre or, in the alternative, in conjunction therewith, pulverised peanut shells or similar fibrous/cellulosic material may be employed.

To effect a reliable and durable seal, especially in the shoulder region of a tyre where there can be expected to be increased deflection, the following additional particulate materials may preferably be included, namely pulverised gum rosin, magnesium carbonate, as well as the aforementioned diatom ite and bentonite. Preferably any powder blend employed will be screened to ensure that no particles therein exceed 40 micron in size. To ensure that any puncture site achieves/exhibits the maximum adhesion capability for the particulate material in the sealant composition, so as to make certain that the particles remain in place within and upon entering the puncture site, a gripping agent such as titanium dioxide may be added to the composition, in an amount of up to 0.15 percent by weight.

In one especially preferred embodiment, the solid component may be made up of: pulverised bark powder (of a particle size less than 100 micron) in an amount of from 0.01 to 1.0 per amount by weight; tea powder (of a particle size less than 100 micron) in an amount of from 0.01 to 1.0 percent by weight; diatomite (of a particle size less than 30 micron) in an amount of from 0.5 to 5.0 per cent by weight and Bentonite (of a particle size less than 40 micron) in an amount of from 0.15 to 5.0 per cent by weight; with the balance including one or more viscosity and suspension agents, corrosion inhibitors and preservatives. In accordance with another aspect of the invention there is provided a composition for sealing punctures in pneumatic tyres, said composition containing:

(a) one or more of propylene glycol, comprising from 10 to 90 percent by weight of the composition, propylene-ethylene glycol blend, comprising from 10 to 90 percent by weight of the composition, and water, comprising from 10 to 90 percent by weight of the composition;

(b) one or more viscosity and suspending agents selected from the group comprising from 0.01 to 1.5 percent by weight of Xanthan gum, from 0.01 to 1.5 percent by weight of methylhydroxyethylcellulose, from 0.01 to 1.5 percent by weight of carboxymethylcellulose, from 0.05 to 3.0 percent by weight of fumed silica, and from 0.01 to 1.5 percent by weight of psyllium husk powder; (c) one or more fillers and sealing particulates selected from the group comprising from 0.01 to 1.5 percent by weight of fine ground rubber crumb sieved to <60 microns, 0.01 to 2.5 percent by weight of fine ground low density polyethylene sieved to <150 microns, from 0.01 to 2.5 percent by weight of ground plastics from the group composed of nylon, polypropylene, styrene and polyethyltetrahydrophtalate, from 0.5 to 5.0 percent by weight of diatomite of <60 microns diameter, from 0.01 to 1.5 percent by weight of bentonite, from 0.01 to 1.5 percent by weight of gum rosin of <60 microns diameter, from 0.05 to 1.5 percent by weight of dissolved rosin, from 0.1 to 2.0 percent by weight of sodium silicate;

(d) one or more corrosion inhibitors selected from the group comprising from 0.05 to 1.5 percent by weight of ammonium bicarbonate, from 0.05 to 1.5 percent by weight of sodium bicarbonate, and from 0.1 to 2.5 percent by weight of sodium borate;

(e) a preservative making up the remainder of the composition. A typical sealing composition in accordance with an especially preferred embodiment of the present invention may be prepared using the fol lowing components/constituents: water, from 20 to 80% by weight; propylene glycol, from 20 to 80% by weight; a polysaccharide gum, as for example Xanthan gum, from 0.1 to 0.3% by weight; a cellulose polymer, as for example carboxymethylcellulose, from 0.01 to 0.3% by weight; fumed colloidal silica, from 0.1 to 0.5% by weight; ammonium bicarbonate, from 0.1 to 1% by weight; borax, from 0.1 to 2% by weight; and ^; a preservative of any known type, in the range of 0.1 to 0.5% by weight.

Insofar as the solid component is concerned, such will preferably include: diatomite (less than 30 micron), in from 1.0 to 5.0% by weight; LDPE (less than 100 micron) in from 0.01 to 0.5% by weight; bentonite (less than 40 micron) in from 0.1 to 1.0% by weight; and gum rosin (less than 30 micron) in from 0.05 to 0.5% by weight. As an alternative to gum rosin, a hot melt adhesive or tackifier (of any known type) may be utilised.

These solid materials should be sieved to ensure that all particle sizes are as specified.

A sealant or sealant composition in accordance with the present invention, being an improvement on latex-based compositions presently in use, constitutes a means for repair (at least temporarily) of a puncture in a pneumatic tyre, the composition being readily capable of being introduced into the damaged tyre by means of compressed air or gas propel lant.

In accordance with another aspect the invention provides an apparatus wherein a pressure source is contained within the container housing a sealing composition of the type referred to above including fillers and particulate material, being selected from the group including pulverised bark powder, pulverised peanut shells and/or the like fibrous material, Equisetum Arvense powder, tea powder, parsley powder, diatomite, bentonite, gum rosin, polyethylene powder and titanium dioxide, for purposes of dispensing thereof.

The arrangement is such as to allow a particle-based sealant composition - as distinct from the prior art latex-based compositions - to be injected into the damaged tyre via the tyre valve, with the valve core or insert in place. Ecological benefits of non-latex sealant compositions are believed to include:

(1) the expiry date of packaged product is increased substantially;

(2) after the tyre is cleaned it is possible to locate the puncture site for inspection and repair and prevent the tyre from being discarded;

(3) particle-based sealant can be allowed to enter the sewer system; (4) packaging can be easily cleaned for re use and/or recycling;

(5) cleaning rags can be washed and re-used repeatedly with no requirement for them to enter the waste stream; (6) a non latex sealant does not have a noxious odour;

(7) the pH of the product is almost neutral and, apart from the ethylene glycol content, is not considered an irritant;

(8) any spills or splashes on clothing or equipment will wipe or wash off readily; and

(9) due to the controlled size of particles in the carrier fluid the valve is left with only minimal contamination after treating the tyre.

DESCRIPTION OF PREFERRED EMBODIMENTS

In order that the invention may be more clearly understood and put into practical effect there shall now be described in detail preferred embodiments of sealing compositions in accordance with the invention. The ensuing description is given by way of non-limitative example only. EXAMPLE 1

In one especially preferred embodiment, a composition in accordance with the present invention may be made up as follows, with all amounts in percentage of the final composition by weight:

(1) propylene glycol 81.0

(2) glycerin 1.0

(3) xanthan Gum .11 (4) Psyllium husk powder .012

(5) carboxymethylcellulose .03

(6) diatomaceous earth .25

(7) gum rosin powder 1.35

(8) magnesium carbonate .135 (9) rice husk powder .3

(10) titanium dioxide .075

(1 1) cork powder .15

(12) bark powder (dry) .1

(13) equisetum powder .1 (14) polyethylene powder .2

(15) water 13.176

(16) sodium bicarbonate .05 (17) ammonium carbonate .05

(18) sodium borate 1.0

(19) formalin .2

(20) fluorescein .012 100

With such a preferred composition, there is a preferred method of preparation, as described hereunder.

The ingredients/components identified as (2) to (14), all in dry form, are added to about 30% of the amount of propylene glycol, accompanied by vigorous stirring, until all the ingredients are fully dispersed (Mixture A).

In a separate vessel the ingredients identified as (16) to (20) should be dissolved in the water (ingredient (15)). This is Mixture B.

The two mixtures can then be added together using high speed agitation (of any known type and using known equipment), to give rise to a curdled gel pre-mix concentrate (C).

To (C) there is then to be added the balance of propylene glycol, together with the glycerin, accompanied by constant stirring or agitation.

The finished product should then be passed through a mechanical strainer and ultrasonic emulsifier (or the equivalent) to ensure any agglomeration or clumping together of particles is removed or separated prior to packaging to ensure valve blockage cannot occur.

Even with such a composition, experimentation has revealed that there could be problems with ensuring correct and proper sealing, especially if the site of the puncture is in the shoulder area of a given tyre. In the light thereof reference is now made to the following Example 3. EXAMPLE 2.

In another especially preferred embodiment, a composition in accordance with the present invention may be made up as follows, with all amounts in percentage by weight:

(1) propylene glycol 82.0

(2) glycerin 0.5 (3) xanthan gum 0.11

(4) Psyllium husk powder 0.012

(5) carboxymethylcellulose 0.03

(6) diatomaceous earth 0.25 (7) gum rosin powder 1.75

(8) titanium dioxide 0.05

(9) rice bran powder 0.45

(10) cork powder 0.15

(1 1) bark powder (dry) 0.10 (12) equisetum powder 0.10

(13) polyethylene powder 0.25

(14) water 13.8936

(15) sodium bicarbonate 0.05

(16) ammonium carbonate 0.05 (17) sodium borate 0.10

(18) formalin 0.20

(19) fluorescein 0.12

With such an especially preferred composition, there is a preferred method of preparation, as described in more detail hereinafter. The ingredients/components identified as (2) to (13) all in dry form, are added to about 30% of the amount of propylene glycol, accompanied by vigorous stirring, until all the ingredients are dispersed (Mixture A). The gum rosin helps in thickening the mixture.

In a separate vessel the ingredients identified as (15) to (19) should be dissolved in the water (ingredient (14)). This is Mixture B.

The two mixtures A and B can then be added together using high speed agitation (of any known type and using known equipment), to give rise to a curdled gel pre-mix concentrate (C).

To (C) there is then to be added the balance of the propylene glycol, together with the glycerin, accompanied by constant stirring or agitation.

The finished composition should then be passed through a mechanical strainer and ultrasonic emulsifier (or the equivalent) to ensure any agglomeration or clumping together of particles is removed or separated prior to packaging to ensure valve blockage cannot occur in use. The liquid resulting therefrom will also exhibit thixotropic properties.

In the instance of a puncture occurring in the tyre's shoulder area the formulation must exhibit exceptional sealing capability. This is essential as virtually no liquid is available to flow to a shoulder area puncture site once the vehicle operates above from 3 to 4 kilometres per hour. The liquid will be confined to the internal crown area inside the tyre chamber due to centrifugal force. It is therefore important that the correct combination of selected ingredients be combined in the right ratio to allow the composition to function satisfactorily regardless of the site of any puncture. Preferably the composition should be capable of sealing a puncture caused by, for example, a spike of up to about 6.25 mm diameter.

To achieve the instant and durable seal necessary requires that Gum Rosin in any especially preferred embodiment be incorporated in an amount of from 1.0 to 2.0% with Polyethylene powder at between from 0.25 to 0.50%.

The other supporting materials are to ensure a total air barrier is achieved due to the matrix of interlocking fibrous particles.

With this composition it is no longer necessary to rely on splashing to supply the sealing composition to the shoulder area of the tyre. The utilisation of cork powder and bark powder enhances the capability of the overall composition to block/seal a puncture, yet at the same time will not prevent that composition from passing through a tyre valve.

EXAMPLE 3. In yet another preferment, a composition in accordance with the present invention may be made up as follows (with all amounts in percentage by weight):

(1) ethylene glycol 25.0

(2) propylene glycol 5.0 (3) glycerine 1.0

(4) marsh mallow root powder 2.5

(5) Psyllium husk powder 0.35 (6) xanthan gum 0.02

(7) carboxymethylcellulose 0.01

(8) Aerosil R2 0.05

(9) magnesium carbonate 0.25 (10) water

(1 1) ammonium bicarbonate 30.0

( 12) sodium bicarbonate 0.15

(13) sodium borate 0.15

(14) formalin 0.30 (15) fluorescein 0.15

(16) propylene glycol 5.0

(17) gum rosen 1.50

(18) ethylene glycol 25.0

(19) propylene glycol 2.56 (20) alcohol 1.0

In accordance with the preferred method of manufacture the ingredients (3) to (9) identified above, in dry form, are added to ingredients (1) and (2) and mixed - by vigorous stirring - until such time as all ingredients are fully dispersed, a procedure which results in what will now be referred to as Mixture (a).

In a separate vessel ingredients (1 1) to (15) are dissolved in water (ingredient 10), thereby giving rise to what will be referred to as Mixture (B).

Mixture (b) is then added to Mixture (A), while stirring, to give rise to what will be referred to as premix concentrate (C). In a steam-jacketed vessel ingredients (16) and (17) are added together and heated to 100⁰C until the Gum Rosin (ingredient 17) is completely melted, thus forming what shall be referred to as Hot phase (D).

In a separate vessel ingredients (18), (19) and (20) are mixed together, forming what will now be referred to as Dilution (E). Hot phase (D) is then stirred into Dilution (E), thus forming Rosin

Solution (F). The Rosin Solution (F) is then added slowly to Concentrate (C) using, preferably, high speed agitation.

The finished composition preferably should then be passed through a 260 micron agitating striation, or the equivalent, to remove any oversized particles.

This composition was arrived at to address problems associated with the difficult sealing area in and around the extreme outer shoulder area of a tyre or the like. It was noted that, due to the nature and size of some puncturing objects, varying degrees of inconsistent sealing performance could occur within that shoulder area resulting in unacceptable loss of air over any given period. In an attempt to overcome this problem an increased amount (percentage) of Psyllium husk powder could be used, but even then such a composition was not completely effective in eliminating the possibility of unwanted air loss with time. It was determined that, in order to boost overall sealing capacity, higher levels of mucilage were required. However, it was also determined that, if Pysllium husk powder was used, then the viscosity of the overall product would become far too high, thereby severely restricting flow of the sealant composition within the tyre chamber, not to mention giving rise to problems in terms of passage at a suitable rate through a given tyre valve.

In accordance with this embodiment this problem or dilemma has been overcome by slightly or marginally increasing the percentage of Psyllium husk powder and replacing other fibre material, as for example bark, with marshmallow root powder (Althaea Officinalis). This served a dual purpose, namely:

(i) enhancing the mucilage characteristic of the sealant; while (j) providing the fibre particles needed to agglomerate in the puncture site.

Further, due to the mucilaginous nature of marshmallow root powder, it was also possible to increase the particle size of the powder.

It should be understood that, in terms of effectiveness, the optimum sealing performance will be achieved by the addition to the aforementioned compositions of natural or synthetic resins which exhibit a degree of "tackiness". In that regard research and experimentation has shown that this property of "tackiness" may be increased by the addition of plasticizers to the resin. Examples of such plasticizers include phthalate, castor oil or glycerine. In terms of production, the process requires melting the resin and adding plasticizer until the material becomes sticky when cold.

In a further embodiment a hot melt adhesive, as for example Instant Lok 449A (National Starch) may be combined with gum resin and cooled to - 30° before grinding to less than 150 micron particle size. It should be understood, however, that other cross-linked (insoluble) natural or synthetic resins may also be employed, including casein latex, RVA, PVM, PVM/MA, PVE and the like. EXAMPLE 4.

In this Example, the formulation is prepared in several parts, with the separate parts identified as A to E inclusive, then combined as explained (with all amounts in weight percent): A Hot Melt Resin Pre-Mix % the preferred resin is National Starch ULTRA-MELT 2642 12.5

(Other resins and combinations that exhibit hydrophobicity and takifying properties, such as National Starch ELOTEX

HD4500, HD 1500, ERASEAL 120ETC, may be employed)

Rice Bran 4.0

Magnesium Carbonate 2.0 Ethylene Glycol 81.5

B Gum Rosin Pre-Mix

Gum Rosin 12.5

Rice Bran 4.0 Magnesium Carbonate 2.0

Ethylene Glycol 81.5 C Casein Pre-Mix

Casein 15.0

Rice Bran 1.0

Magnesium Carbonate .5 Ethylene Glycol 83.5

D Rosin Soluble Solution Pre-Mix

Ethylene Glycol 18.0

Propylene Glycol 25.0 Water 15.8

Ammonia 20% 3.5

Alcohol 3.5

Formalin .2

Propylene Glycol 25.0 Gum Rosin 9.0

E Dilution Pre-Mix

Propylene Glycol 2.1

Glycerine 1.0 Ethylene Glycol 36.0

Water 60.0

Ammonia .3

Formalin .3

Opacifier (PVA) .15 Fluorosciene .02

Formulation

In this preferred Example the overall formulation, derived from the Parts A to E as set out above, is made up as follows: Hot melt Pre-mix A 10.25

Gum Rosin Pre-mix B 12.5

Casein Pre-mix C 4.25 - 20 -

C Casein Pre-Mix

Casein 15.0

Rice Bran 1.0

Magnesium Carbonate .5 Ethylene Glycol 83.5

D Rosin Soluble Solution Pre-Mix

Ethylene Glycol 18.0

Propylene Glycol 25.0 Water 15.8

Ammonia 20% 3.5

Alcohol 3.5

Formalin .2

Propylene Glycol 25.0 Gum Rosin 9.0

E Dilution Pre-Mix

Propylene Glycol 2.1

Glycerine 1.0 Ethylene Glycol 36.0

Water 60.0

Ammonia .3

Formalin .3

Opacifier (PVA) .15 Fluorosciene .02

Formulation

Gum Rosin Pre-mix B 12.5

Casein Pre-mix C 4.25 - 21 -

Glycerine 3.0

Skim Milk Powder .75

Gum Rosin Solution D 9.0

Magnesium Carbonate .5

Dilution Solution 57.25

Water 2.5

Procedure

Premixes A B and C are separately blended and temperature reduced to -20°c and separately milled to approx 150-200 micron particle size.

Rosin solution D is prepared by adding Gum Rosin into half of the Propylene Glycol (35%) and heated to 80° until fully melted. The balance of Propylene Glycol is mixed with the remaining ingredients and finally the hot phase of Rosin/Glycol is added slowly while stirring. The combined mixture is then cooled to -30°c and passed through a

Colloid Mill ensuring all solid particulates are finely and evenly dispersed into a colloidal suspension with particle size not exceeding 130 micron some settling of ingredients is apparent and product must be shaken before use. EXAMPLE 5. In order to further enhance the sealing capacity of the composition in accordance with the present invention, particularly in the extreme shoulder area of a vehicle tyre or the like, being that area bordering on the sidewall where high distortion or deflection of the rubber can be expected to occur, with a composition where latex has been substituted, the following alternative composition has been tested.

Most of the vegetable fibres, psyllium, etc., may be substituted with rice bran. The suspending agents -xanthan gum, aerosil R2, etc. - may also be taken out, with their function being taken over by the rice bran, this providing that the rice bran is present in a range of from 3.0 to 6.0 percent by weight. For further simplification ammonia may play the role of corrosion inhibitor and pH adjuster, replacing the bicarbonate. - 22 -

Optimal sealing performance may be achieved by combining gum resin and a combination of hot melt adhesives having high "task" properties, such as for example "Instant" - LOK 449A (National Starch). Skim milk powder may also be employed to increase the rate of flow through the valve core.

With this embodiment, an especially preferred composition is as follows, with all values being in weight percent: INGREDIENT

MATERIAL PERCENT RANGE ( (11)) GGuumm rreessiinn 11..00 0.3 to 3.0

(2) Hot melt adhesive 2.5 0.5 to 5.0

(3) Magnesium carbonate 1.5 0.3 to 3.0

(4) Skim milk powder 1.0 0.3 to 3.0

(5) Rice bran 5.0 1.0 to 8.0 ( (66)) EEtthhyylleennee g gllyyccooll 3300..00 5.0 to 90.0

(7) 10% Solubilised gum resin 5.0 2.0 to 15.0

(8) Ethylene glycol 6.0 5.0 to 90.0

(9) Propylene glycol 5.0 5.0 to 90.0

(10) Water 35.0 5.0 to 90.0 ( (11 11)) AAmmmmoonniiaa 00..22 0.1 to 2.0

(12) Preservative 0.2 0.1 to 2.0

(13) PVA opacifier 0.2 0.2 to 4.0

With this embodiment ingredients (1) to (6) are blended together and temperature lowered to approximately -30⁰C, and then ground to from 150 to 200 micron. That blend is then mixed with ingredients (7) to (14) and temperature lowered - again to -30⁰C and then passed through a colloid mill to ensure that particles are firmly and evenly dispersed into a colloidal suspension that will flow through a valve core without blockage.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as

"comprises" and "comprising", will be understood to imply the inclusion of a - 23 -

stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference to any prior art in this specification is not, and should not, be taken as an acknowledgment or any form or suggestion that the prior art forms part of the common general knowledge in Australia.

Finally, it is to be understood that the foregoing description refers merely to preferred embodiments of the invention, and that variations and modifications will be possible thereto without departing from the spirit and scope of the invention.

Claims

- 24 -CLAIMS:

1. A sealing composition for the sealing of a punctured tyre including a liquid carrier, one or more viscosity and suspending agents, one or more fillers and sealants, and one or more corrosion inhibitors.

2. The sealing composition as claimed in Claim 1, wherein said liquid carrier comprises between 5 and 95% by weight of the composition, the said one or more viscosity and suspending agents comprise between 0.01 and 1.0% by weight of the composition, the said one or more fillers and sealants comprise between 0.01 and 5.0% by weight of the composition, and the said one or more corrosion inhibitors comprise between 0.01 and 2.0% by weight of the composition.

3. The sealant composition as claimed in Claim 2, wherein said liquid carrier is selected from the group consisting of water, mixtures of water and propylene glycol, mixtures of water and ethylene glycol, mixtures of water, propylene glycol and ethylene glycol, and mixtures of propylene glycol and ethylene glycol.

4. The sealant composition as claimed in Claim 2, wherein said one or more viscosity and suspending agents are selected from the group consisting of polysaccharide gums, carboxymethylcellulose, methylhydroxyethylcellulose and fumed silica.

5. The sealant composition as claimed in Claim 2, wherein said one or more fillers and sealants is selected from the group consisting of pulverised bark powder, pulverised peanut shells, pulverised fibrous material, pulverised cellulosic material, powdered Equisetum Arvense, tea powder, parsley powder, diatomite, bentonite, gum resin, and titanium dioxide.

6. The sealant composition as claimed in Claim 2, wherein said one or more corrosion inhibitors is selected from the group consisting of ammonium carbonate, sodium bicarbonate and sodium borate.

7. A composition for sealing of a punctured tyre, as claimed in either

Claim 1 or claim 2, and which is introducible into the tyre via a tyre valve thereof without any need to first remove the tyre valve core or - 25 -

insert and without resulting in any blockage of the tyre valve itself and any associated tubing, with the entire composition being capable of passing through the restricted passage existing within the valve.

8. A composition for sealing punctures in pneumatic tyres, said composition containing:

(b) one or more viscosity and suspending agents selected from the group comprising from 0.05 to 1.5 percent by weight of Xanthan gum, from 0.01 to 1.5 percent by weight of methylhydroxyethylcellulose, from 0.01 to 1.5 percent by weight of carboxymethylcellulose, from 0.05 to 3.0 percent by weight of fumed silica, and from 0.01 to 1.5 percent by weight of psyllium husk powder;

(c) one or more fillers and sealing particulates selected from the group comprising from 0.01 to 1.5 percent by weight of fine ground rubber crumb sieved to <60 microns, from 0.01 to 2.5 percent by weight of fine ground low density polyethylene sieved to <150 microns, from 0.01 to 2.5 percent by weight of ground plastics from the group composed of nylon, polypropylene, styrene and polyethyltetrahydrophtalate, from 0.5 to 5.0 percent by weight of diatomite of <60 microns diameter, from 0.01 to 1.5 percent by weight of bentonite, from 0.01 to 1.5 percent by weight of gum resin of <60 microns diameter, from 0.05 to 1.5 percent by weight of dissolved resin, from 0.1 to 2.0 percent by weight of sodium silicate;

(d) one or more corrosion inhibitors selected from the group comprising from 0.5 to 1.5 percent by weight of ammonium - 26 -

bicarbonate, from 0.05 to 1.5 percent by weight of sodium bicarbonate, and from 0.1 to 2.5 percent by weight of sodium borate; and (e) a preservative making up the remainder of the composition.

9. A composition for use in the sealing of a damaged inflatable article, said composition including: a liquid carrier, made up of water and/or propylene glycol and/or ethylene glycol and/or propylene-ethylene glycol blend, in an amount of up to 90 percent by weight; one or more viscosity and suspension agents selected from the group comprising

Xanthan gum, methylhydroxyethylcellulose, carboxymethylcellulose, fumed silica and/or psyllium husk powder; one or more fillers and sealing particulates selected from the group comprising ground rubber crumb, polyethylene, bark powder, peanut shells or the like fibrous material, ground plastics, diatomite, bentonite, gum resin and/or sodium silicate; and one or more corrosion inhibitors selected from the group comprising ammonium bicarbonate, sodium bicarbonate and/or sodium borate.

10. A composition for use in the sealing of a damaged inflatable article, said composition including water, from 20 to 80% by weight; propylene glycol, from 20 to 80% by weight; a polysaccharide gum, from 0.1 to 0.3% by weight; a cellulose polymer, as for example carboxymethylcellulose, from

0.01 to 0.3% by weight; fumed colloidal silica, from 0.1 to 0.5% by weight; ammonium bicarbonate, from 0.1 to 1% by weight; borax, from 0.1 to 2% by weight; Diatomite (less than 30 micron), from 1.0 to 5.0% by weight;

LDPE (less than 100 micron) from 0.01 to 0.5% by weight; Bentonite (less than 40 micron) from 0.1 to 1.0% by weight; gum resin (less than 30 micron) from 0.05 to 0.5% by weight. and a preservative from 0.1 to 0.5% by weight. - 27 -

1 1. A composition for use in sealing a punctured vehicle tyre, said composition containing the following constituents (with all amounts in percentage of the final composition by weight):

(1) propylene glycol 81.0

(2) glycerin 1.0

(3) xanthan gum .11

(4) Psyllium husk powder .012

(5) carboxymethylcellulose .03

(6) diatomaceous earth .25 ( (77)) g guumm rreessiinn p poowwddeerr 1.35

(8) magnesium carbonate .135

(9) rice husk powder .3

(10) titanium dioxide .075

(H) cork powder .15 ( (1122)) bbaarrkk p poowwddeerr ( (ddrryy)) .1

(13) equisetum powder .1

(14) polyethylene powder .2

(15) water 13.176

(16) sodium bicarbonate . .05 ( (1177)) aammmmoonniiuumm ccaarrbboonnaattee .05

(18) sodium borate 1.0

(19) formalin .2

(20) fluorescein .012

12. A composition for use in sealing a punctured vehicle tyre, said composition containing the following constituents (with all amounts in percentage of the final composition by weight):

(1) propylene glycol 82.0

(2) glycerin 0.5

(3) xanthan gum 0.1 1 ( (44)) PPssyylllliiuumm hhuusskk p poowwddeerr 0.012

(5) carboxymethylcellulose 0.03

(6) diatomaceous earth 0.25 - 28 -

(7) gum resin powder 1.75

(8) titanium dioxide 0.05

(9) rice bran powder 0.45

(10) cork powder 0.15

(H) bark powder (dry) 0.10

(12) equisetum powder 0.10

(13) polyethylene powder 0.25

(14) water 13.8936

(15) sodium bicarbonate 0.05

(16) ammonium carbonate 0.05

(17) sodium borate 0.10

(18) formalin 0.20

(19) fluorescein 0.12

13. A composition for use in sealing a punctured vehicle tyre, said composition containing the following constituents (with all amounts in percentage of the final composition by weight):

(1) ethylene glycol 50.0

(2) propylene glycol 12.56

(3) glycerine 1.0

(4) marsh mallow root powder 2.5

(5) Psyllium husk powder 0.35

(6) xanthan gum 0.02

(7) carboxymethylcellulose 0.01

(8) Aerosil R2 0.05

(9) magnesium carbonate 0.25

(10) water 30.0

(H) ammonium bicarbonate 30.0

(12) sodium bicarbonate 0.15

(13) sodium borate 0.15

(14) formalin 0.30

(15) fluorescein 0.15

(16) gum resin 1.50 - 29 -

(17) ethyl alcohol 1.0

14. A composition for use in sealing a punctured vehicle tyre, said composition containing the following constituents (with all amounts in percentage by weight): a hot melt pre-mix consisting making up 10.5% of the final composition, and consisting of the following constituents (with all amounts in percentage by weight of the pre-mix) a hydrophobic tackifying resin 12.5 rice bran 4.0 magnesium carbonate 2.0 ethylene glycol 81.5; a gum resin pre-mix, making up 12.5% of the final composition, and consisting of the following components (with all amounts and percentage by weight of the pre-mix) gum resin 12.5 rice bran 4.0 magnesium carbonate 2.0 ethylene glycol 81.5; a casein pre-mix, making up 4.25% of the final composition and consisting of the following components (with all amounts in percentage by weight of the pre-mix): casein 15.0 rice bran 1.0 magnesium carbonate 0.5 ethylene glycol 83.5 glycerine 3.0 skim milk powder 0.75; a resin soluble solution pre-mix, making up 9% of the final composition, and consisting of the following components (with all amounts in percentage by weight of the pre-mix) ethylene glycol 18.0 propylene glycol 50.0 - 30 -

water 15.8 ammonia (20%) 3.5 ethylalcohol 3.5 formalin 0.2 gum resin 9.0 magnesium carbonate 0.5; a dilution solution pre-mix, making up 57.25% of the final composition, and consisting of the following components (with all amounts in percentage by weight of the pre-mix) propylene glycol 2.1 glycerin 1.0 ethylene glycol 36.0 water 60.0 ammonia 0.3 formalin 0.3 opacifier (PVA) 0.15 fluorescein 0.02; glycerin 3.0; skim milk powder 0.75; magnesium carbonate .05; water 2.5.

15. A method for the preparation of a composition as claimed in Claim 14, wherein the hot melt resin pre-mix, gum resin pre-mix and casein pre-mix as disclosed in Claim 14 are separately blended and reduced in temperature to -20⁰C and separately milled to approximately 150 -

200 micron particle size; a resin soluble solution pre-mix as disclosed in Claim 14 is prepared by adding gum resin to half of the propylene glycol and heated to 80⁰C until fully melted, the remainder of the propylene glycol being mixed with the remaining ingredients of the pre-mix, followed by the slow addition of the hot phase of the resin glycol mixture with stirring; all components of the final composition are then added together, - 31 -

cooled to -3O⁰C and passed through a colloid mill to form a colloidal suspension with particle size not exceeding 130 micron.

16. A method for the preparation of a composition for the sealing of a punctured tyre, substantially as described herein with reference to any one of the Examples.