GB1597105A

GB1597105A - Smoking product

Info

Publication number: GB1597105A
Application number: GB4963977A
Authority: GB
Original assignee: Gallaher Ltd
Current assignee: Gallaher Ltd
Priority date: 1977-12-23
Filing date: 1977-12-23
Publication date: 1981-09-03

Description

(54) SMOKING PRODUCT (71) We, GALLAHER LIMITED, a British company, of 138 York Street, Belfast, Northern Ireland, do hereby declare the invention, for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement: Some tobacco substitutes consist essentially of a carbonaceous fuel consisting of at least 80%, and preferably over 90%, carbon by weight, and including no elements other than carbon, hydrogen and oxygen. The fuel is prepared by the controlled pyrolysis of a polymeric organic material, particularly a cellulose-based material such as viscose.The raw material from which the fuel is produced, and hence the fuel, preferably consists of a coherent mass of fibres which have, after the pyrolysis, a cross sectional dimension of between 1 and 50 u, usually between 10 and 30 ja. Upon pyrolysis the organic material is degraded with the result that when the fuel is burnt, the combustion products are essentially carbon dioxide and water which involve no health risks when inhaled. A tobacco substitute of this kind is described, for example, in our British Patent Specification No. 1,431,045.

When used as a tobacco substitute, the fuel is associated as necessary with stimulants, flavouring agents, smoke producing agents, and combustion modifying (which term includes ash producing) agents. These associated agents are invariably more complex in chemical structure that the carbonaceous fuel and they must be carefully selected so that they not only perform their primary function, but also do not make an unacceptable contribution from the health viewpoint to the smoke to be inhaled. The present invention in concerned with the selection of smoke producing agents.

Smoke producing agents are added to the pyrolysed carbonaceous fuel because the predominant combustion products of the carbonaceous fuel are carbon dioxide and water, which are colourless gases and vapours and it is necessary to give the smoker the visual satisfaction of both side stream and main stream smokes. The latter should have the capability of producing an exhaled smoke occurs when smoking natural tobacco. The requirements of a smoke producing agent are that it distils without decomposition upon proximity to the burning part of the fuel and is entrained in the gas stream drawn by the smoker through the cigarette, condensing in the cooler gas stream and forming a stable suspension of minute droplets or particles.Smoke producing agents in the form of natural oils or alcohols have been proposed but these are not entirely satisfactory, either because of their inefficient distillation into the gas stream, requiring a large quantity of the smoke producing agents to be used, or, in the case of alcohols, because their high hygroscopicity and prevalence to hydrogen bonding which has caused them to be retained in undesirably high quantities in the lungs, thus producing no exhaled smoke.

In accordance with the invention, in a smoking product for use as a tobacco substitute and comprising a pyrolysed carbonaceous fuel which incorporates a smoke producing agent, the smoke producing agent consists of a physiologically acceptable ali- phatic ester of a mono, di-, or poly-carboxylic acid, the ester having a boiling point between 2000C and 4500C and containing no elements other than carbon, hydrogen, oxygen, and possibly a physiologically acceptable metal such as sodium, potassium, calcium, magnesium or strontium. To avoid staining of the subsequent wrapper, the ester is preferably a solid, having a melting point greater than 400C.

Such esters are found to act as good smoke producing agents. The volatility of the esters, having a boiling point between 2000C and 4500C, is not so high that the majority of the smoke producing agent distils off and is lost to side stream smoke but is such that sufficient remains to produce an adequate main stream smoke. On the other hand the volatility of the esters is not so low that appreciable cracking of the esters occurs before distilling into the main stream smoke.

The selected esters also have the advantage that they will form stable aerosols with a mean particle size in the order of 0.5 y.

The comparatively inert and non-hygroscopic nature of esters enables the smoke which they produce to be inhaled and exhaled by the smoker with the minimum of retention in the lungs. The carboxylic acids from which the esters are formed may be mono-, di-, or poly-carboxylic straight chain carbon organic oxy- or hydroxy-acids, and there may be advantages if the acid is unsaturated. By an oxy-acid is meant one in which an oxygen atom is present in the carbon chain of the molecule to provide an ether linkage.

The alcohols from which the esters are formed may be mono-, di-, or tri-hydric alcohols including those which contain an oxygen atom in the carbon chain e.g. diethylene glycol. There are also believed to be advantages if the alcohol is unsaturated. In particular the alcohols preferred are those in which the carbon atom tB to the hydroxyl group is not bonded to any hydrogen atoms.

When such alcohols are used to prepare the latter are blocked esters e.g. neopentyl esters. This configuration results in esters exhibiting increased thermal stability. Methyl esters are also preferred since as they do not contain any 6 carbon atom they also exhibit good thermal stability.

Examples of suitable esters are methyl pal- mitate, methyl stearate, vinyl stearate, dimethyl sebacate, dimethyl dodecandioate, dimethyl tetradecandioate, dimethyl hexadecandioate, glyceryl trimyristate, pentaerythrityl tetracetate, monoethyl sebacate, trimethyl citrate, myristyl myristate, palmityl palmitate, glyceryl monostearate, glyceryl trilaurate, and vinyl oleate.

These smoke producing agents may be dispersed in the fuel by dipping the pyrolysed carbonaceous material in a solution of the agent and subsequently deliquoring and drying the material. Simple solvents, such as water, ethyl alcohol, methyl alcohol, dichioro- methane, hexane, ether, and acetone may be used as solvents and ethyl alcohol is preferred. With approximately a 100% solution retention by weight of organic residue after deliquoring, the concentration of the contacting solution may be readily arranged to provide an addition of ester in the range 5 to 15% by weight of organic residue, which is acceptable.

Proprietory flavouring agents are preferably also applied to the strand to complete the formulation of the smoking product. These flavouring agents may be added in a similar manner to the smoke producing agents.

The production of a cigarette from a smoking product manufactured in accordance with the invention and incorporating the concepts forming the subject of our Applications No.

41271/76, 49636/77, 4%38/77, and 19419/80 (Serial Nos. 1,597,101, 1,597,102, 1,597,104 and 1,597,107) will now be described with reference to the accompanying diagrammatic drawings.

A viscose mix consisting of regenerated cellulose incorporating 1.5 % by weight of the cellulose of titanium dioxide and 5% by weight of the cellulose of active carbon, both the additives have a particle size of less than 2 ,u., were prepared in a spinning bath. 8 denier fibres were spun from the mix in the bath, the fibres were given a crimp with 7 waves per cm. and formed into a tow 2. The tow was passed through a cutter 3 which cut the fibres into staple lengths 4 which were 73 mm. long. The staple fibres were then carded on a conventional carding machine 5 to produce a sliver 6 with a linear density of 18 g/m. The sliver may be stored or immediately treated further.

The sliver was passed through a pair of nip rollers 7 and through a bath 8 containing a 0.055 molar solution of calcium formate, deliquored by passing through further nip rollers 9, and dried in a hot air dryer 10.

This treatment produced a resulting calcium ion content of 0.2% by weight of the weight of organic viscose in the sliver strand.

The sliver was then pyrolysed by transporting it longitudinally on a stainless steel belt at 60 cm. per min. through a furnace 11 which was 5 metres long and had a temperature profile of 2500C at its inlet end rising gradually to 4200C at the 3 metre point, rising to 8000C at the 4 metres point, and continuing at that temperature to the outlet end of the furnace. The pyrolysed strand contained 89.2% organic residue, 9.4% titanium dioxide, and 1.4% calcium. The organic residue represented a yield of 17% weight of the original viscose and the organic residue had a composition of 97.9% carbon, 0.3% hydrogen and 1.8% oxygen. The pyrolysed fibres has a mean diameter of 13.5 y.

The pyrolysed strand was then passed through a bath 12 containing a 0.5 molar aqueous solution of tripotassium phosphate, a 1.0 molar aqueous solution of potassium dihydrogen phosphate and a 2.5% aqueous solution of nicotine hydrogen tartrate. After leaving the bath 12 the strand was passed through cushioned nip rollers 13 and a hot air dryer 14. This left the strand loaded with 70 g. of phosphate salts per 100 g. of carbonaceous organic residue and 7% of nicotine hydrogen tartrate by weight of carbonaceous organic residue.

Under some circumstances it might be necessary to recycle the strand around a path 15 and through the bath 12 again to leave the strand impregnated with these quantities of salts.

The strand was then passed through a second bath 16 containing a 10% by weight ethyl alcohol solution of glyceryl trimyristate smoke producing agent and a flavouring agent.

On leaving the bath 16 the strand was passed through further cushioned nip rollers 17 and a hot air dryer 18. Again under some circumstances the strand may be recycled around a path 19 and through the bath 16 again.

This treatment left the strand impregnated with 0.47 g. of the ester per m. of strand.

The resulting strand was stored in a can or on a reel from which it was subsequently fed through a garniture for wrapping with a conventional wrapper in a cigarette making machine 20 to produce a continuous cigarette rod of 25 mm. circumference, the filler formed by the strand providing a weight of 300 mg.

of organic residue per cigarette length of 56 mm. of rod. The rod was then cut into standard 56 mm. lengths 21 and fitted with a 10 mm standard filter in a tipping machine 22 to produce tipped cigarettes 23. The final composition of the cigarettes, excluding the filter, was organic residue 42.0%; phosphate 25.5%; titania 4.5 %; calcium, sodium and potassium metal ions 14.5 % nicotine salt 3.5%; smoke producing ester 4.5%; flavouring agent 1.0%; and wrapper 4.5%.

The cigarette pressure drop was found to be 100 mm. of water with a hardness of 90%.

On smoking under standard smoking conditions an organic vapour phase of 0.1%, and a particulate matter yield of less than 0.25 of a standard flue cured cigarette was obtained from the carbonaceous filler.

We recognise that our British Patent Specification No. 1,431,045 discloses a smoking product comprising a pyrolysed carbonaceous fuel which incorporates a smoke producing agent consisting of glyceryl triacetate, and no claim is now made to such smoking product Subject to the foregoing disclaimer, WHAT WE CLAIM IS: 1. A smoking product for use as a tobacco substitute and comprising a pyrolysed carbonaceous fuel which incorporates a smoke producing agent consisting of a physiologically acceptable aliphatic ester of a mono-, di-, or poly-carboxylic acid, the ester having a boiling point between 2000C and 4500C and containing no elements other than carbon, hydrogen, oxygen, and, possibly, a physiologically acceptable metal.

2. A product according to claim 1, in which the ester contains no elements other than carbon, hydrogen, and oxygen.

3. A product according to claim 1, in which the carboxylic acid from which the ester is formed is a mono-, di-, or polycarboxylic straight chain carbon or oxy-acid.

4. A product according to claim 2, in which the carboxylic acid from which the ester is formed is a mono-, di-, or polycarboxylic straight chain carbon or oxy-acid.

5. A product according to claim 1, or claim 2, in which the carboxylic acid from which the ester is formed is a mono-, di-, or poly-carboxylic hydroxy acid.

6. A product according to any one of the preceding claims, in which the carboxylic acid and/or the alcohol from which the ester is derived is unsaturated.

7. A product according to any one of the preceding claims, in which the ester has a melting point greater than 400C.

8. A product according to claim 2 or claim 3, in which the alcohol from which the ester is formed is a mono-, or di-hydric alcohol.

9. A product according to claim 1 or claim 4, in which the alcohol from which the ester is formed is a mono-, or di-hydric alcohol.

10. A product according to any one of claims 1 to 7, in which the alcohol from which the ester is formed is a tri-hydric alcohol.

11. A product according to claim 8, in which the alcohol is of the type in which the carbon atom IR to the hydroxyl group is not bonded to any hydrogen atoms.

12. A product according to claim 9 or claim 10, in which the alcohol is of the type in which the carbon atom tB to the hydroxyl group is not bonded to any hydrogen atoms.

13. A product according to any one of the preceding claims in which the fuel is the pyrolysis product of a fibrous viscose material.

14. A product according to claim 1, substantially as described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. through further cushioned nip rollers 17 and a hot air dryer 18. Again under some circumstances the strand may be recycled around a path 19 and through the bath 16 again. This treatment left the strand impregnated with 0.47 g. of the ester per m. of strand. The resulting strand was stored in a can or on a reel from which it was subsequently fed through a garniture for wrapping with a conventional wrapper in a cigarette making machine 20 to produce a continuous cigarette rod of 25 mm. circumference, the filler formed by the strand providing a weight of 300 mg. of organic residue per cigarette length of 56 mm. of rod. The rod was then cut into standard 56 mm. lengths 21 and fitted with a 10 mm standard filter in a tipping machine 22 to produce tipped cigarettes 23. The final composition of the cigarettes, excluding the filter, was organic residue 42.0%; phosphate 25.5%; titania 4.5 %; calcium, sodium and potassium metal ions 14.5 % nicotine salt 3.5%; smoke producing ester 4.5%; flavouring agent 1.0%; and wrapper 4.5%. The cigarette pressure drop was found to be 100 mm. of water with a hardness of 90%. On smoking under standard smoking conditions an organic vapour phase of 0.1%, and a particulate matter yield of less than 0.25 of a standard flue cured cigarette was obtained from the carbonaceous filler. We recognise that our British Patent Specification No. 1,431,045 discloses a smoking product comprising a pyrolysed carbonaceous fuel which incorporates a smoke producing agent consisting of glyceryl triacetate, and no claim is now made to such smoking product Subject to the foregoing disclaimer, WHAT WE CLAIM IS:

1. A smoking product for use as a tobacco substitute and comprising a pyrolysed carbonaceous fuel which incorporates a smoke producing agent consisting of a physiologically acceptable aliphatic ester of a mono-, di-, or poly-carboxylic acid, the ester having a boiling point between 2000C and 4500C and containing no elements other than carbon, hydrogen, oxygen, and, possibly, a physiologically acceptable metal.