CLIAMS:1. An insoluble, cross linked smokeable filler sheet comprising:

a. borate salts;
b. atleast one non-combustible, inorganic filler;
c. atleast one combustible, organic binder;
d. atleast one aerosol generating material; and
e. optionally a colorant and/or fragrance.

2. The smokeable sheet as claimed in claim 1, wherein said borate salts is borax.

3. The smokeable sheet as claimed in claim 1, wherein amount of said borate salt ranges from 0.01-50% by wt., preferably 0.5-2% by wt.

4. The smokeable sheet as claimed in claim 1, wherein said inorganic filler are selected from a group consisting of Calcium carbonate, talc, chalk, alumina, zeolite and TiO2.

5. The smokeable sheet as claimed in claim 1, wherein amount of said inorganic filler ranges from 60 to 90 wt%.

6. The smokeable sheet as claimed in claim 1, wherein said organic binders are selected from a group consisting of guar gum, acacia gum, xanthan gum; and other binders like polyvinyl alcohol, polyvinyl acetate,.

7. The smokeable sheet as claimed in claim 1, wherein amount of said organic binder ranges from 5 to 20 wt%.

8. The smokeable sheet as claimed in claim 1, wherein said aerosol generating material are chosen from a group consisting of glycerol, propylene glycol, triethylene glycol.

9. The smokeable sheet as claimed in claim 1, wherein amount of said aerosol generating material ranges from 0.1 to 15 wt%.

10. The smokeable sheet as claimed in claim 1, wherein said coloring or flavoring materials are chosen from a group consisting of cocoa, caramel, chocolate, toffee and liquorices.

11. The smokeable sheet as claimed in claim 1, wherein amount of said colorant or flavoring materials ranges from 0.1-10 wt%.

12. The smokeable sheet as claimed in claim 1, wherein the ratio of organic binder to inorganic filler to aerosol generating material to colorant/ fragrant is 12:80:6:2.

13. A process for the preparation of insoluble smokeable sheet comprising steps of
a. casting slurry into thin sheets/films and spraying 0.1 to 8.0% wt. of borate salt solution before drying; and
b. curing said thin sheets in hot oven for 10-40 mins at 50-120oC temperature.

14. The process for the preparation of insoluble smokeable sheet as claimed in claim 13, wherein said smokeable sheets are insoluble for more than 48 hours.

15. The process for the preparation of insoluble smokeable sheet as claimed in claim 13, wherein composition of slurry comprises of Guar gum, Calcium carbonate, glycerol, caramel, water.

16. The process for the preparation of insoluble smokeable sheet as claimed in claim 13, wherein composition of thin sheets/film comprises of Guar gum, Calcium carbonate, glycerol, caramel, Borax, water.

17. The process for the preparation of insoluble smokeable sheet as claimed in claim 13, wherein said thin sheets have a thickness of 0.01 mm to 0.25 mm. ,TagSPECI:Field of the Invention
The present invention relates to alternate smokeable sheets, more particularly the present invention relates to water insoluble, smokeable sheet which utilizes the process of cross linking mechanism.
Background and the Prior Art
The present invention is related to alternate smokeable sheets which can be used in tobacco / cigarette industry. But these tobacco substitute sheets are hydrophilic in nature and get dissolved when contacted with water which poses a major challenge to be used as adjuncts (contextually, they are also known as neutral filler sheets) in tobacco industry. Few attempts have been made to overcome the said problems reported in various prior arts. A friendly process for making Modified tobacco products (MTP) by feeding tobacco substituted sheets (TSS) at any point of the primary processing of tobacco also can take the heat of high drying efficiency driers. It is always challenging to maintain the TSS not to melt or deform during primary processing. One of such alternative measure which is widely used is alternate smokeable sheets which can be used in tobacco / cigarette industry. The tobacco substitute sheets which have been used in the prior art are hydrophilic in nature and get dissolved when contacted with water which poses a major challenge in tobacco industry. There are various methods have been attempted so far to make water insoluble, however with considerable shortcomings.
US3070486 relates to paper and paper products, especially cigarette paper. Calcium carbonate is added to the paper pulp during making of the sheet. The prior art achieves the objective of continuous burning of the cigarette paper by filling or loading it with an alkaline filler, commonly calcium carbonate (chalk) which is incorporated in the paper sheet during manufacture thereof. The chalk filler is used in an amount such that it constitutes about 20% to 30% of the total weight of the filled paper. Calcium carbonate is an inorganic substance and that alone would render it undesirable for use as the filler for cigarette paper if organic filler imparting the same desirable properties to the paper were made available.
US4564031 relates to a smokeable, coherent sheet of disintegrated vegetable materials and/or tobacco waste, said sheet being provided with a water-insoluble film on one surface and being obtained in that the vegetable materials and/or tobacco waste are pressure-formed with binding agents and water, the share of which is lower than that of the dry substance employed, between forming elements, the formed, coherent and still moist sheet is coated at a moisture content of 30 to 50% with a solution or suspension having at least one water-soluble, modified pectin from the group of low-esterified pectin with an esterification degree of below 40% and/or amidified, low-esterified pectin with an amidation degree of over 15%, the modified pectin is contacted with bivalent and/or trivalent metal ions and the coated sheet is dried, with the concentration of the modified pectin on the sheet surface being at least 0.5 percent by weight, as referred to the dry weight of the finished product. This smokeable sheet shows a good smoke quality, an increased filling power of the tobacco produced there from and a high moisture resistance.
For the improvement of the various physical properties of the sheet material produced by the extruder method and/or roller method, the sheet surface has been coated with various, both water-soluble and water-insoluble binding agents, for which purpose for instance solutions or suspensions of sodium carboxymethyl cellulose, solutions of guar gum, pectin, alginate or locust bean gum were used, which optionally also contained cross-linking agents such as glyoxal or other dialdehydes.
US 3353541 relates generally to tobacco compositions and improved adhesive materials as binders for reconstituted tobacco compositions. The Pectic substances found in tobacco plants contain ac1 groups and differ considerably from commercially available pectins found in other plants, including sugar beet pectins and citrus and fruit pectins. Tobacco protopectins are uniquely insoluble in hot water as compared 5Q with protopectins from many other sources and comprise mainly water-insoluble pectins (protopectins) consisting of the calcium and magnesium salts of partially esterified and slightly acetylated polymers of galacturonic acid. The divalent calcium and/or magnesium atoms act as cross links between acid chains, thus making the polymers water-insoluble.
None of the prior art teaches the process to make the water insoluble tobacco substituted sheet comprising atleast one non-combustible inorganic filler, atleast one combustible organic binder results as adjuncts, to be used in tobacco industry, wherein said sheet substantially reduces the tobacco content in the regular, smokeable cigarettes. "Adjuncts" can be defined as any sheet / material which are also known as neutral filler sheets or alternate smokeable sheets contemplated in the present invention to substantially reduce the use of tobacco content in regular cigarettes. The alternate smokeable sheet contains more than 70% of inorganic filler material along with some binder, aerosol former and other additives. Thus it decreases the amount of tobacco as well as combustible organic matter available in the overall blend, second, it releases glycerol into main stream smoke to dilute the concentration of tobacco combustion sourced particulate constituents.
Object of the present invention
An object of the present invention is to overcome the drawbacks of the prior art.
Another object of the present invention is to provide an alternate smokeable sheet made up of inorganic filler materials.
Yet another object of the present invention is to provide an alternate smokeable sheet utilizing the process of cross linking mechanism by using borate and its salts as cross linking agent.
Yet another object of the present invention is to provide a process for the preparation of the alternate smokeable sheet prepared by sheet utilizing the process of cross linking mechanism.
Summary of the present invention
An aspect of the present invention is to provide an insoluble, cross linked smokeable filler sheet comprising
a) borate salts;
b) atleast one non-combustible inorganic filler;
c) atleast one combustible organic binder;
d) atleast one aerosol generating material; and
e) optionally a colorant and/or fragrance;

Another aspect of the present invention is to provide a process for the preparation of insoluble smokeable sheet comprising steps of
a) casting slurry into thin sheets/films and applying 0.1 to 8.0% wt. of borate salt solution before drying; and
b) curing said thin sheets in hot oven for 10-40 mins at 50-120oC temperature;

such that said 0.1 to 8.0% wt. of borate salt is sprayed onto said slurry.
Brief Description of Accompanying Drawings

Figure 1 illustrates borax cross-linking mechanism

Detailed Description of the Invention
The present invention provides an alternate smokeable sheet with inorganic filler materials. These smokeable sheets of the present invention are prepared by using a cross linking mechanism. The cross linking mechanism involves use of borate and its salts as cross linking agents. Borates are the name for a large number of boron-containing oxyanions and they are the derivatives of boric acids. Borax is mainly selected as borate salt. Borate salts are used for cross-linking of the Guar gum, PVOH type of binder (binder).
The expression "alternate smokeable sheet" is defined as a "sheet" that is made up of inorganic fillers that can be used along with tobacco containing smoking materials such as cigarettes but necessarily does not contain tobacco.
The cross linking mechanism as used in present invention is illustrated in figure 1
Borax (Na2B4O7) hydrolyzes in solution to generate Borate ions, B(OH)4. Borate ion in solution coordinates with 4 hydroxyl groups of two guar gum chain molecules, resulting in a di-diol complex. This is called cross-linking.
In an embodiment of the present invention there is provided a composition of smokeable sheet which uses borate and its salts as the cross linking agent. The said composition of the smokeable sheet with borate and its salts as cross linking agent comprises atleast one inorganic filler, atleast one organic binder, atleast one aerosol generating material and optionally a colorant and/or fragrance.
The amount of cross linking agent ranges from 0.01-50% by wt., preferably 0.5-2% by wt.
Non-combustible inorganic filler can be defined as materials that do not aid in combustion.
Non-combustible inorganic filler can be selected from a group comprising one or more of Ca-carbonate, talc, chalk, alumina, zeolite, TiO2.
The amount of inorganic filler ranges from 60 to 90 wt%.
Combustible organic binder can be defined as materials that aids in combustion.
Combustible Organic binders can be selected from gums including guar gum, acacia gum, xanthan gum; and other binders like polyvinyl alcohol, polyvinyl acetate, etc. The amount of organic binder ranges from 5 to 20 wt%.
Suitable aerosol generating means include polyhydric alcohols such as glycerol, propylene glycol, triethylene glycol. The amount of aerosol generating material ranges from 0.1 to 15 wt%.
Suitable colouring or flavouring materials include cocoa, caramel, chocolate, toffee or liquorices. The amount of colorant is present in an amount ranging from 0.1-10 wt%.
Another embodiment of the present invention provides a process for the preparation of the alternate smokeable sheets with borate and its salts as the cross linking agent.
Process of preparation:
The slurry is cast into the thin sheet or film of and before drying 0.1 to 8.0% wt. of borate salt solution such as borax was sprayed onto it. The thin sheet was then cured in hot oven for 10 to 40 mins at 50 to 120oC. The sheet material showed acceptable non-solubility in water. The sheet remained insoluble in the water even after 48 hrs.
Curing is a term in polymer chemistry and process engineering that refers to the toughening or hardening of a polymer material by cross-linking of polymer chains, brought about by chemical additives, ultraviolet radiation, electron beam or heat.
The solution could be sprayed on the sheet before drying or semi-dried sheet could be impregnated into the salt solution.
Mixing of the cross linking agent in the composition would immediately crosslink the binder, resulting in a rubber like mass. From that cross-linked rubber like mass, sheet formation would be impossible. That is why only after the casting of the film, cross-linking solution should be sprayed.
Slurry can be defined as a watery mixture of insoluble matter.
The composition of slurry comprises of Guar gum, Calcium carbonate, glycerol, caramel, water.
The film as disclosed above comprises of Guar gum, Calcium carbonate, glycerol, caramel, Borax, water.
The present invention is now illustrated by means of non limiting examples:
Example 1: Composition of alternate smokeable sheets using borate salts as cross linking agent (working example).
Ingredient % wt. Wt. in gm
Guar Gum (2%) 12 600
Ca-carbonate filler 80 80
Glycerol 6 6
Caramel solution (50%) 2 4

The ratio of the components Guar gum: Ca-carbonate: Glycerol: Caramel is 12:80:6:2
0.1 to 8% borax was sprayed onto the sheet to cure the material.
The desired result of the water insoluble smokeable filler sheet was obtained because of the use of binder specific cross-linking agent in a specific sequential addition process i.e., spraying of the borax salt solution onto the sheet
Process of preparation
The slurry was cast into the thin sheet or film and before drying 1% of borate salts i.e. borax was sprayed onto it. The thin sheet was then cured in hot oven for 20 mins at 80oC temperature. The sheet material showed acceptable non-solubility in water. The sheet remained insoluble in the water for more than 48 hrs.
The composition of slurry comprises of Guar gum, Calcium carbonate, glycerol, caramel, water.
The film as disclosed above comprises of Guar gum, Calcium carbonate, glycerol, caramel, Borax, water.
Curing is a term in polymer chemistry and process engineering that refers to the toughening or hardening of a polymer material by cross-linking of polymer chains, brought about by chemical additives, ultraviolet radiation, electron beam or heat.
Borax is present in an amount ranging from 0.1-10% of the final dried sheet.
Examplev2: The sheet was made using Borate salts (negative example)
Ingredient % wt. Wt. in gm
Na-Alginate (2%) 12 600
Ca-carbonate filler 80 80
Glycerol 6 6
Caramel solution (50%) 2 4

The ratio of the components Na-Alginate: Ca-carbonate : Glycerol : Caramel = 12:80:6:2
Borax is not mixed with the composition but is sprayed onto the sheets. Borax present ranges from 0.1-10% of the final dried sheet.
The final sheet was water soluble in nature.
Borate cross-linking is only specific to guar gum, PVOH type of binder. Na-alginate cannot be cross-linked by using borax solution.
PVOH type binders are polyvinyl alcohol polymer or copolymers of PVOH and other polymers.
Use of Na-alginate as binder along with borax as cross-linking agent gives water soluble sheets. In contact with water the sheet structure gets deformed and finally it goes to the water.
Process of preparation:
The slurry was cast into the thin sheet or film and before drying 2% of borate salt solution such as borax was sprayed onto it. The thin sheet was then cured in hot oven for 20 mins at 90°C temperature. The sheet material was soluble in water. Since the borax solution is binder specific, the sheet was soluble in water. Borate salts cannot be mixed with the composition but only can be sprayed onto the sheets.
The desired result of the water insoluble smokeable filler sheet was obtained because of the use of binder specific cross-linking agent in a specific sequential addition process (i.e., spraying of the solution onto the sheet).
Example 3: (negative example to show that although the specific binder is used such as guar gum, it has to be sprayed whereas, if it has been mixed, the resultant sheet would not be formed and also it dissolves in water which is unacceptable.)
Smoking material according to the invention were made with 2% guar gum solution, Ca-carbonate filler, Glycerol, 4% borax solution and 50% Caramel solution so that final composition was –
Guar gum : Ca-carbonate : Glycerol : borax: Caramel = 12:80:6:0.5:2
During the addition of the borax solution the slurry became semi-solid insoluble lump from which sheet/film formation was impossible.
Here, the addition sequence of the cross-linking agent (Borax) is different from the previous example. The desired product of water insoluble sheet was obtained only because of the addition of the binder specific cross-linking agent in a specific sequential addition process.