US3885574A

US3885574A - Smoking mixture

Info

Publication number: US3885574A
Application number: US125872A
Authority: US
Inventors: James Borthwick; James Forrester Morman
Original assignee: Imperial Chemical Industries Ltd
Current assignee: Imperial Group PLC
Priority date: 1970-03-23
Filing date: 1971-03-18
Publication date: 1975-05-27
Anticipated expiration: 1992-05-27
Also published as: SE383953B; NL7103799A; CH568027A5; FI51036B; DE2114084A1; IL36421A; IT1043835B; NL150319B; LU62830A1; IE35236L; CA923006A; FI51036C; DE2114084B2; GB1299296A; NO126416B; JPS5233200B1; ZA711889B; IL36421A0; DE2114084C3; IE35236B1

Abstract

Tobacco substitute based smoking mixture containing a minimum amount of organic combustible material and a maximum amount of harmless inorganic filler, the composition of the filler having been selected so as to impart a commercially acceptable burning rate to the mixture.

Description

United States Patent [1 1 Borthwick et al.

-451 May 27, 1975 1 SMOKING MIXTURE [73] Assignee: Imperial Chemical Industries Limited, London, England [22] Filed: Mar. 18, 1971 [21] App1.No.: 125,872

[30] Foreign Application Priority Data Mar. 23, 1970 United Kingdom 13860/70 [52] 11.8. CI 131/2; 131/17;131/14 0C [51] Int. Cl A24b 15/00 [58] Field of Search 131/2,15,l7,l40144 [56] References Cited UNITED STATES PATENTS 2,809,904 10/1957 Koree 131/2 2,914,072 11/1959 Tyrer et al..... 131/17 2,930,720 3/1960 Finberg 131/17 3,003,895 10/1961 Grunwald 131/17 3,106,210 10/1963 Reynolds et a1. 131/17 R 3,112,754 12/1963 Diaz 131/2 3,459,195 8/1969 Silberman 1111/]? 3,461,879 8/1969 Kirkland 131/2 3,529,602 9/1970 Hind et a1. 131/2 3,545,448 12/1970 Mormon 131/22 3,608,560 9/1971 Briskin et al 131/2 OTHER PUBLICATIONS Miano et al., Tobacco Substitute," German Pat. Spec. No. 1,900,491 of Nov. 27, 1969 Abstract.

Primary Examiner-Melvin D. Rein Attorney, Agent, or F irmCushman, Darby & Cushman [5 7] ABSTRACT Tobacco substitute based smoking mixture containing a minimum amount of organic combustible material and a maximum amount of harmless inorganic filler, the composition of the filler having been selected so as to impart a commercially acceptable burning rate to the mixture.

9 Claims, No IDrawings SMOKING MIXTURE This invention relates to smoking mixtures and to methods of producing such mixtures.

Smoking mixtures are systems by which desirable flavours and drugs are conveniently distilled or aerosoled to the mouth during the smoking action. Being of natural origin, tobacco contains many chemical species which, although necessary for the growth and survival of the plant, contribute nothing to the smoking enjoyment and may unfortunately be the precursors of chemicals which are injurious to health.

There have been many attempts to lessen the health hazard from tobacco smoking by adding to the to bacco, chemicals which are reputed to favourably change the chemical composition and biological activity of the smoke.

More recently, substitutes for tobacco have been claimed. See British Pat. Nos. 1,055,473 and 1,143,500 and U.S. Pat. No. 3,106,209 in which cellulose, oxidised cellulose and lettuce leaves are used. In these compositions, pretreatment and additives are claimed to affect the smoke so that it is acceptable tastewise and is less hazardous to health.

The ideal smoking substitute would be a material or fuel which burns harmlessly to give the energy to distil, aerosol or pyrolytically produce and distill only the necessary amounts of those components required for taste and drug effects.

Unfortunately, fuels which burn to give only harmless products are difficult to find. The most obvious fuel would be elemental carbon which should combust to harmless carbon dioxide. Unfortunately again, the commercially available forms of carbon, e.g. carbon black, are prolific producers when smoked of polyaromatic hydrocarbons. A large part of these hydrocarbons may, of course, come from the impurities produced in the manufacture of these carbons.

An object of the present invention is to provide a smoking composition which is suitable for aerosoling flavours and drugs but which contains a minimum amount of combustible organic material or smokeproducing fuel which on burning inevitably gives rise to some harmful products.

According to the present invention there is provided a smoking mixture comprising an organic combustible material or fuel, a (on pyrolysis) harmless inorganicfiller and a binder, the inorganic filler being present in quantities such as to considerably reduce the amount of harmful products produced on combustion of the mixture and the composition of the filler having been selected by ion balancing to impart a commercially acceptable burning rate to the smoking mixture.

The organic combustible material or fuel may comprise to 80 percent by weight of the smoking mixture, preferably -30 percent by weight.

The harmless inorganic filler may comprise 15 to 65 percent by weight of the smoking mixture, preferably 40-60 percent by weight.

The mixture may also contain a plasticiser/humectant in addition to the binder. l

From another aspect, the present invention is a method of manufacturing said smoking mixture comprising preselecting a specific organic combustible material as smoke-producing fuel and preselecting the proportion by weight of said combustible material to be incorporated in the smoking mixture, admixing said combustible material with a predetermined amount of harmless inorganic filler, the ionic content of which has been balanced to impart a commercially acceptable burning rate to said preselected amount of organic combustible material and finally forming a shaped arti cle of the mixture utilising a binder.

The shaped article is preferably a film, extruded filament or tape.

For the purpose of this invention the term harmless inorganic filler is intended to include inorganic salts of some relatively simple organic acids. For example, formates, oxalates, tartrates and citrates can be used as harmless inorganic fillers but these are less satisfactory than the preferred completely inorganic materials on account of some undesirable pyrolytic decomposition. This decomposition becomes potentially more harmful as the size of the organic molecule increases.

The inorganic filler preferably comprises a mixture of two or more such inorganic salts admixed in quantities such as to obtain the balance of anions and cations most appropriate for imparting the desirable rate of combustion to the preselected amount of the specific organic combustible material incorporated in the smoking mixture.

By way of example, an acceptable rate of combustion for the smoking mixture of the invention can be correlated to the puff number of 10-12 of a machine-made standard Class B British cigarette containing 1.1 g. tobacco, where each puff is of 25 ml. volume in two seconds, followed by a 58 second rest or smouldering period and where the mm. cigarette is smoked to a butt length of 20 mm.

The smoking mixture of the invention is intended to be used as a comparatively safe neutral substrate which burns at a correct rate and has a low content of relatively harmless organic fuel and a high content of harmless inorganic filler. Flavourants, drugs, medicaments, materials to improve ash coherence and colour and other additives, including tobacco, can be incorporated as desired to produce the final product sold to the smoker.

The smoking mixture containing such a high content of harmless inorganic material can advantageously be produced by a process similar to reconstituted tobacco processes which utilise film-forming agents or binders. Such a film-forming process enables a relatively large proportion of inorganic materials to be incorporated into the smoking mixture.

The film-forming agent or binder and the plasticiserlhumectant incorporated in the mixture are also organic in nature but they may have an inorganic content and they can be carefully chosen from materials known to burn to produce lesser amounts of harmful products than tobacco.

Preferred binders include carboxymethyl cellulose and its salts and other carboxylated carbohydrates. Where the amount of binder employed is very small other less satisfactory binder materials such as natural gums, guar gums, locust bean gums and other synthetic binders such as methyl and other ethers of cellulose may be used.

Preferred plasticiser/humectants include glycerol, ethylene glycol and polyethylene glycol.

Organic combustible materials suitable as smokeproducing fuel in the mixtures of the invention include carbohydrates, modified carbohydrates and certain aldol condensation products. Carbon samples which produce lower amounts of polycyclic aromatic hydrocarbons can also be used.

The smoke-producing carbohydrate may advantageously comprise cellulose, cellulose derivatives, sugars, starch, alginate, pectin, natural gum, glucuronic acid or polygalacturonic acid.

The modified carbohydrate may advantageously be prepared as disclosed in our US. Pat. No. 1,1 13,979 by subjecting it to a catalysed degradation process at a temperature of lO-250C until the weight of the degraded material is less than 90 percent of the dry weight of the original carbohydrate.

Preferred degradation catalysts include sulphuric acid, sulphamic acid and ammonium sulphamate. The modified carbohydrate may be oxidised cellulose.

The aldol condensation products may advantageously be prepared by acid or based catalysed condensation of a compound of the formula RCOCH CH- COR (I) (or a precursor thereof) wherein R and R which may be the same or different, each represent a hydrogen atom, or an alkyl, hydroxyalkyl or formyl group.

Preferably, the aldol condensation product comprises the condensate from succinaldehyde, acetonyl acetone or the condensate from a precursor of (1) which is a compound containing a furan ring structure.

A further object of the present invention is to utilise the combustion modifying properties of known inorganic fillers to reduce the quantity of health hazard chemicals in smoking compositions, this object being attained by reducing the amount of organic fuel in the smoking mixtures and making up the weight with said inert fillers.

The choice of the inert inorganic fillers to be incorporated in the smoking mixture determines the rate of combustion or how many normal puffs can be had from a given weight of the mixture.

The art of making an acceptable burning composition involves choosing the correct proportions of fillers which relatively promote or retard the combustion.

Earlier publications in the tobacco substitute field have suggested that burning control of tobacco substitutes is exerted through hydrated metal salts. The use of such materials as alkali nitrates to improve the fireholding of tobacco blends is well known. It has also been suggested that potassium is an essential constituent for the proper burning of tobacco. It is our experience that the water content of tobacco substitutes has only a relatively small effect on the number of puffs given by a particular weight of cigarette but may determine whether a composition is glowproofed or burns satisfactorily. Hydrated and non-hydrated versions of the same salt can be used. On the other hand, we have found that burning control is strongly influenced by the nature of the combination of cations and anions present. This does not imply that the combustion rate is uninfluenced by other considerations such as fuel particle size or texture of the smoking material.

The art of retarding combustion without making a composition glowproof yet obtaining the correct puff count from a given weight of smoking mixture by the use of these inert fillers is another key to the success of the present invention. Combustion accelerators are combined with combustion retardants in proportions which give a desirable rate of combustion for a specific organic fuel and a particular amount thereof in the mixtures. Whilst this principle of the invention is described and illustrated herein with reference to commonly available inert fillers, this principle can be applied to any inorganic material which proves to be a safe filler for use in a smoking mixture.

It is impossible to specify that some ionic species retard while others accelerate glow combustion since some fuels do not sustain combustion in isolation. It suffices to say that we have found that with a number of fuels a number of commonly available acidic anions influence combustion rate and that the order of the retarding ability of a selection of them is formate oxalate s silicate carbonate chloride sulphate phosphate borate. Isolated exceptions to these orders indicated can, however, be found. Amongst the cations the order is sodium=potassium calcium magnesium. With the cations it would appear their effect on the burning rate depends on their basicity, the most significant change being from calcium to magnesium.

This implies, for example, that in smoking mixtures which are identical except that A contains sodium sulphate and B contains the same proportion by weight of magnesium sulphate, A will burn away more quickly. Similarly, in two compositions identical except that A contains calcium carbonate and B contains calcium borate, Composition A will burn away more quickly than Composition B.

The fillers chosen should not have the power to retain excessive quantities of water, otherwise glowproofing will result.

It is preferable, but not essential, that the fillers should be insoluble in water. Calcium carbonate has been found to be a most useful agent for use as a combustion accelerator balanced against combustion retarding agents such as calcium orthophosphate (CaH- P0 211 0), magnesite (MgCO light basic magnesium carbonate (3MgCO .Mg.(Ol-1) .3H O), and calcium sulphate (CaSO /2H O). Using these and other inorganic materials, films can be made which give shred with filling powers comparable to tobacco shred.

Although the above description and the Examples which follow illustrate the required balance of ions being obtained by varying the respective amounts of two inorganic salts, it is possible that a suitable rate of combustion for a smoking mixture could be attained using an optimum amount of a single inorganic salt as inert filler.

The main advantages of the smoking mixtures of the invention compared with earlier synthetic products and, of course, tobacco, are as follows:

a. The lower amounts of organic materials present mean that proportionately lower amounts of the harmful smoke products are formed whilst maintaining a desirable rate of combustion for the mixture. In this connection, tests carried out on smoking mixtures of the invention show a reduction in the benzpyrene content of the smoke and a reduction in other chemical species known or suspected to be harmful because of the reduced organic fuel content. Furthermore, the mixtures of the invention advantageously have the same burning characteristics as tobacco based smoking mixtures. They keep lit and continue to burn and they have the same rate of combustion as tobacco.

b. The lower amounts of organic materials present gave rise to lower amounts of any odour off notes" which may arise from smoking these materials (e.g. the burnt paper note of cellulose). Lower amounts of added masking agents are required in these instances.

c. The process of the invention permits the use of fuels which were previously impossible to use on account of their physical properties, e. g. the high solubility and non-fibrous nature of sucrose, glucose and glucuronic acid. The high inorganic content gives body to the films of these materials which were previously unusable in smoking mixtures.

The principle of ion balancing of the inert fillers is illustrated in the following tables. According to this principle the specific fuel and the amount thereof to be used in the mixture are first selected and then ion balance tests are effected to determine the composition having the most desirable rate of combustion. As can be seen from the tables the ions are investigated separately to ascertain their relative suitabilities for the selected fuel.

Tables 1 to 5 illustrate the comparative retarding powers of cations of various inert fillers when added to a smoking mixture of the following composition:

by weight Thermally degraded cellulose* 53 SCMC Glycerol 14 Calcium carbonate 5 Citric acid 4 Potassium citrate 5 Ammonium sulphate 4 The thermally degraded cellulose was prepared as follows and in accordance with the method described in our British Patent Specification No. 1,113,979. 1,0 part by weight of sheeted alpha-cellulose was immersed in a 50% aqueous Solution of ammonium sulphamate and the pulp compressed between rolls to leave 1.0 part of solution in the pulp. The pulp was airdried at 45C and then heated at 240C so that the pulp became black and the weight of the degraded material was 75% of the original weight of alpha-cellulose plus ammonium sulphamate. The black pulp sheet was allowed to cool and was then ground to a powder passing a 120 BSS sieve.

In each case the inorganic filler constituted 5 percent of the total weight of the smoking mixture. The effect of the basicity of the cation is clearly indicated in each table.

Table l added Filler (by weight) Basicity of cation Puff number MgSO 7H O 5 increasing 23 CaSO.,.%H,O 5 14.5 K 80 5 14.3 Na SO 5 14.25

Table 2 added Puff Filler (by weight) Basicity of cation number Mg (PO 5 increasing 18.2 CaHPO,.2H O 5 16.0 Na HlO 5 I 16.0 Na HPO .l2H O 5 15.0

Table 3 added Basicity Filler (by weight) of cation Puff number CaB O, 5 increasing 19.8 Na mo, 5 I: 19.8 Na B O 101-1 0 5 17.0

Tables 6 to 8 illustrate the retardant properties of different anions. The same basic smoking mixture of Tables l to 5 was used in the tests for Tables 6 to 8.

Table 6 Effectiveness of Puff Filler added anion number CaP O 5 decreasing retardant properties 19.8 CaHPO,.2H O 5 ditto 16.0 CaSO .%H O 5 ditto 14.5 CaCO:, 5 ditto 12.0 CaCl .6H O 5 ditto 1 1.5 Ca Oxalate 5 ditto l 1.0 Ca Formate 5 ditto 9 Table 7 Effectiveness of Puff Filler added anion number Na B O 5 decreasing retardant properties 19.8 Na l-[P0 5 ditto l 6.0 Na SO 5 ditto 14.25 NaCl 5 ditto 10.8 Na CO 5 ditto 1 0.4 Na SiO 5 ditto 9.4

Table 8 Effectiveness of Puff Filler added anion number Mg (PO 5 decreasing retardant properties 18.2 MgSO .7H O 5 ditto 1 7.5 MgCO; 5 ditto l 5.0 MgCl .6l-l O 5 ditto 1 3.0 Mg Silicate 5 ditto 12.0 Mg Oxalate 5 ditto 12.0 Mg Formate 5 ditto 10.8

A second smoking mixture was prepared of similar composition to that utilised for the tests of Tables 1 to 8 but with 53 parts by weight thermally degraded cellulose replaced by 53 parts by weight carbon black as fuel. Tests similar to those of Tables 1 to 8 were carried out on the carbon black based smoking mixture and the results are indicated in the following Tables 1a, 2a, 4a, 6a and 8a which correspond respectively to Tables 1, 2, 4, 6 and 8. No Tables corresponding to Tables 3, 5 and 7 were produced.

Table la Table 8a Filler added Basicity of cation Puff number Effccthflcness 9f Puff Filler added anion number MgSO .7H O 5 increasing 1 1.7 S CaSO4 i/2H2O 5 Mg;,(PO decreasing retardant properties 16.7 SO 5 g5 MgSO .7H O 5 ditto llr7 K2304 5 g3 MgCl .6H O 5 ditto 10.3 MgCO 5 ditto 9.2 Mg Silicate 5 ditto 9.0 Mg Oxalate 5 ditto 8.6 Mg Formate 5 ditto 7.8

The following Tables 9 and 9a illustrate the effect of the ratio of percent CaCO percent Cal-lPO .2H O on Table 2a the uff number res ectivel of thermal] de raded P Y 8 cellulose based smoking mixtures and carbon black Flue added l of Puff number based smoking mixtures. In the case of Table 9 it is to Mgqwom 5 increasing 167 be noted that 15-17 is the correct puff number for Cal-lPO .2H O 5 14.7 hand rolled cigarettes made wlth commercially avail- NazHPO 5 H able hand rolling paper in contrast to machine made Na HPO .l2H O 5 9.5 0

cigarettes which have a puff number of 12.

Table 9 thermally degraded cellulose 28 28 28 28 28 28 SCMC l0 l0 l0 l0 l0 l0 Glycerol l4 l4 l4 l4 l4 l4 %CaCO l0 l2 l4 l6 18 2O CaHPO .2H O 23 21 l9 l7 l5 K citrate 4 4 4 4 4 4 Citric acid 4 4 4 4 4 4 (NH4)2SO4 5 5 5 5 5 5 Ratio CaCO:

CaHPO .2H O 1:2.5 l:l.92 lzlr5 l:l.l9 1:0.94 120.75 Puffnumber l7l8 l6-l7 l516 14-15 l3l4 Glow- Correct puff too low proofed numbers puff number The smoking mixtures above were hand rolled with paper commercially available in Britain for this purpose. For comparison purposes 1.1 g. hand rolled tobacco cigarettes give l5- l7 puffs. 1.1 g. machine made cigarettes with the more porous paper used by United Kingdom cigarette manufacturers give 10-12 puffs.

Table 9a Carbon black 28 28 28 28 28 28 SCMC 10 10 10 10 10 10 Glycerol l4 l4 l4 l4 l4 l4 %CaCO l0 l2 14 16 18 2O %CaHPO .2H O 25 23 2| 19 l7 l5 K Citrate 4 4 4 4 4 4 Citric acid 4 4 4 4 4 4 (NHJZSQ, 5 5 5 5 5 5 Ratio CaCO CaHPO .2H O 112.5 11192 1:15 11.19 1:0.94 1:0.75 Puff number ll-l2 10-1] 10 9-10 8-9 7-8 Correct puff No. range too low puff No.

Table 4a The five compositions indicated in Table 9 and Table I 9a as having a correct puff number constituted the first Filler added Basicity of cation P ff number five Examples of smoking mixtures of the invention. M CO 5 Tables 9 and 9a thus serve to illustrate how the ion bal- 5 if 2:? ancing principle of the present invention is applied.

Applying the principle illustrated in Tables 9 and 9a Table 6a and utilising the information given in the earlier tables a further seven examples of smoking mixtures accord- Effectiveness of Puff ing to the invention were prepared, the compositions Filler added anion nu her and preparations of which are illustrated in Examples I 6 to 23 below. gzgg zi g decreasmg 5 52 propcrlles lg; In Examples 6 to 9 the organic fuel is thermally de- 4' 2 Ca Oxalate 5 92 graded cellulose prepared according to the method Ca Formate 5 ditto 7.0 reviousl described with re ard to Tables 1 to 9. In CaCO; 5 ditto 6,7 p y g Examples 10 to 13 the organic fuels are respectively sucrose, glucose, alpha-cellulose and polygalacturonic acid.

In each of Examples 6 to 13 the final composition as aforesaid was reached after tests similar to those indicated in Tables 9 and 9a had been effected. The compositions actually illustrated in Examples 6 to 13 are those having the best puff numbers. Examples 14 to 23 illustrate further variations in the parameters of the in vention.

EXAMPLE 6 5.38 parts thermally degraded cellulose powder, 4.26 parts powdered chalk, 7.10 parts powdered magnesium carbonate and 60 parts water were stirred together. 1.34 parts glycerol and 20 parts water were stirred together then added to the previous mixture. The whole was paddle-stirred together for 30 minutes.

The mixture was transferred to a Probst & Class mill and at a gap setting of 2, milled for minutes. The gap was reduced to setting Zero and the mixture milled for a further 5 minutes. At the end of this period, 1.92 parts SCMC were added quickly into the centre of the vortex and the slurry immediately discharged into a clean container then paddle stirred for 15 minutes. Sufficient water was then added to reduce the viscosity to 55,000 cps.

Film material was made by spreading the slurry at 0.020 in. on a band-drier and drying by means of hot air at 150C. The band speed was 19 ft. min. The film material was shredded and processed satisfactorily on cigarette making machinery.

1.1 g. cigarettes gave standard puffs. The smoke was mild to taste.

Dry weight composition of Example 6:

Thermally degraded cellulose 26.9 SCMC 9.6 Glycerol 6.7 CaCO; 21.3 MgCO 35.5

EXAMPLE 7 5.38 parts thermally degraded cellulose powder, 3.84 parts powdered chalk, 6.72 parts powdered light basic magnesium carbonate and 60 parts water were stirred together. 1.36 parts glycerol, 0.78 part potassium citrate and 20.0 parts water were stirred together, then added to the previous mixture. The whole was paddlestirred together for 30 minutes.

The mixture was transferred to a Probst & Class mill and at a gap setting of 2, stirred for 5 minutes. The gap was reduced to zero and the mixture milled for a further 5 minutes. At the end of this time, 1.92 parts SCMC were added quickly into the vortex and the slurry immediately discharged into a clean container. The slurry was paddle-stirred for minutes. Sufficient water was then added to reduce the viscosity to 50,000

Film material was made by spreading the slurry at 0.020 in. on a band-drier and dried by hot air at 150C. The band speed was 19 ft. min..

The film material was shredded and processed satisfactorily on cigarette making machinery.

1.1 g. cigarettes gave 10 standard puffs. The smoke was mild to taste.

Dry weight composition of Example 7:

7r Thermally degraded cellulose 26.9 SCMC 9.6 Glycerol 6.7 CaCO 19.3 3.MgCO .Mg(OH) .3H O 33.6 K Citrate 3.9

EXAMPLE 8 4.08 parts thermally degraded cellulose powder, 4.34 parts powdered chalk, 5.75 parts calcium hydrogen orthophosphate and 60 parts water were stirred together. 2.33 parts glycerol, 0.57 part potassium citrate, 0.72 part citric acid, 0.57 part ammonium sulphate and 20 parts water were stirred together then added to the previous mixture. The whole was stirred together for 30 minutes.

The mixture was transferred to a Probst & Class mill and at a gap setting of 2 milled for 5 minutes. The gap was reduced to zero and the mixture milled for a further 5 minutes. At the end of this period 1.76 parts SCMC were quickly added into the centre of the vortex and the slurry immediately discharged into a clean container, then paddle-stirred for 15 minutes. The viscosity was 42.000 ops.

Film material was made by spreading the slurry at 0.010 in. on a band-drier and drying by means of hot air at C. The band speed was 22 ft. min..

1.1 g. cigarettes gave 10 standard puffs. The smoke was mild to taste.

Dry weight composition of Example 8:

Thermally degraded cellulose 50 parts thermally degraded cellulose powder, 3.2 parts powdered chalk, 5.7 parts powdered magnesium carbonate, 0.95 part powdered bentonite and 70.0 parts water were stirred together. 1.25 parts glycerol, 0.7 part potassium citrate and 11.5 parts water were stirred together and then added to the previous mixture. The whole was stirred together for 15 minutes.

The mixture was transferred to a Probst & Class mill and at a gap setting of 2 milled for 5 minutes. The gap was now reduced to zero and the mixture milled for a further 5 minutes. At the end of this time, 1.7 parts SCMC were added quickly into the centre of the vortex and the slurry immediately discharged into a clean container. The slurry was paddle-stirred for 15 minutes and at the end of this period sufficient water was added to reduce the viscosity to 60,000 cps.

Film material was made by spreading the slurry at 0.020 in. on a band-drier and drying by means of hot air at 150C. The band speed was 16 ft. min".

1.1 g. cigarettes gave 1 1 standard puffs. The smoke was mild to taste.

The dry weight composition of Example 9 was:

Thermally degraded cellulose 26.9 SCMC 9.6 Glycerol 6.7 CaCO 17.3 MgCO 30.6 Bentonite 5.0 K Citrate 3.9

EXAMPLE 10 5.6 parts sucrose, 7.8 parts calcium carbonate, 2.0 parts light basic magnesium carbonate, 0.8 part potassium citrate, 1.1 parts citric acid and 0.8 part ammonium sulphate were stirred for half an hour with 68.6 parts of water. The mixture was transferred to a probst & Class mill and at a gap setting of 2 milled for 5 minutes. The gap was reduced to setting zero and the mixture milled for a further 5 minutes. At the end of this time 2.0 parts SCMC were added quickly and the slurry discharged immediately into a container and paddlestirred for 15 minutes. 11.3 parts of water were added to reduce the viscosity to 56,000 cps.

Film material was prepared by spreading the slurry at 0.018 in. on a band-drier and drying by means of air at 60C. The band speed was 9 ft./min.

The film material was very sensitive to moisture. It could, however, be satisfactorily shredded and processed by cigarette making machinery if the relative humidity of the atmosphere was maintained at 58-60 RH and 60F. Under these conditions the equilibrium moisture content of the shred was 6.3-6.8.

1.1 g. cigarettes gave 10 puffs. The smoke from the cigarettes was mild to taste.

The dry weight composition of Example 10 was:

Sucrose 28 SCMC 10 CaCO 39 Light basic Mg carbonate 10 K citrate 4 Citric acid 5 (NI-10 50., 4

EXAMPLE 1 l 5.5 parts glucose, 7.6 parts calcium carbonate, 2.0 parts light basic magnesium carbonate, 0.75 part potassium citrate, 0.75 part ammonium sulphate and 1.0 part citric acid were stirred for half an hour with 67.2 parts of water. The mixture was transferred to a Probst & Class mill and at a gap setting of 2 milled for 5 minutes. The gap was reduced to setting zero and the mixture milled for a further 5 minutes. At the end of this time 20 parts SCMC were added quickly and the slurry discharged immediately into a container and paddlestirred for minutes. 13.3 parts of water were added to reduce the viscosity to 60,000 cps.

Film material was prepared by spreading the slurry at 0.020 in. on a band drier and drying by means of air at 150C. The band speed was 18 ft./min.

The film material was very sensitive to moisture. It could, however, be satisfactorily shredded and processed by cigarette making machinery if the relative humidity of the atmosphere was maintained at 53-55 percent RH and 60F. Under these conditions the equilibrium moisture content of the shred was 5-6.

Dry weight composition of Example 11:

Glucose 28 SCMC 10 CaCO 39 Light basic Mg carbonate 10 K citrate 4 Citrate acid 5 02 4 4 EXAMPLE 12 4.5 parts alpha-cellulose powder, 3.5 parts chalk, 5.1 parts calcium hydrogen orthophosphate, 2.5 parts glycerol, 0.8 part citric acid, 0.7 part ammonium sulphate, 0.7 part potassium citrate and 71 parts water were stirred together for half an hour. The mixture was transferred to a Probst & Class mill and at a gap setting of 2 milled for 5 minutes. The gap was reduced to setting zero and the mixture milled for a further 5 minutes. At the end of this period 1.7 parts of SCMC were added quickly and the slurry discharged immediately into a container and paddle-stirred for 15 minutes. 9.5 parts of water were added to reduce the viscosity to 46,000 cps.

Film material was made by spreading the slurry at 0.012 in. on a band-drier and drying by means of hot air at C. The band speed was 20 ft./min.

1.1 g. cigarettes gave 10 standard puffs. The smoke from the cigarettes was mild.

The dry weight composition of Example 12 was:

Alpha-cellulose SCMC Glycerol CaCO CaHPO,,.2H O K citrate Citric acid (NH4)2SO4 EXAMPLE 13 2.04 parts of glycerol and 1.17 parts potassium citrate were dissolved in 250 mls. of water. 2.88 parts of SCMC were then added to the solution and stirred for 15 minutes. 8.07 parts of alginic acid, 10.08 parts of magnesium carbonate and 5.76 parts powdered chalk were mixed together in the dry state, then added to the previous mixture. The whole was stirred for 1 hour.

Film material was made by spreading the slurry at 0.02 inches on glass plates and left to dry. The film material was humidified and shredded. Ten cigarettes were hand rolled with Imperial Verge paper.

1.1 g. cigarettes gave 11 standard puffs. The smoke was mild to taste.

Dry weight composition:

Alginic acid 26.9 Glycerol 6.8 SCMC 9.6

-Continued CaCO 19.2 M co 33.6 Potassium Citrate 3.9

EXAMPLE 14 2.04 parts of glycerol and 1.17 parts of potassium citrate were dissolved in 150 mls. of water. 2.88 parts of SCMC were then added to the solution and stirred for 15 minutes. 8.07 parts of thermally degraded sucrose, 10.08 parts of magnesium carbonate and 5.76 parts of powdered chalk were mixed together in the dry state then added to the previous mixture. The whole was stirred for 1 hour.

1.1 g. cigarettes gave standard puffs.

Dry weight composition:

Thermally degraded sucrose 26.9 Glycerol 6.8 SCMC 9.6 CaCO 19.2 Potassium Citrate 3.9 Magnesite 33.6

EXAMPLE 2.04 parts of glycerol and 1.17 parts of potassium citrate were dissolved in 150 mls. of water. 2.88 parts of sodium alginate were then added to the solution and stirred for 15 minutes. 8.07 parts of thermally degraded cellulose, 11.88 parts of magnesium carbonate and 3.96 parts powdered chalk were mixed together in the dry state then added to the previous mixture. The whole was stirred for 1 hour.

1.1 g. cigarettes gave 10 standard puffs. The smoke was mild to taste.

Dry weight composition:

' Thermally degraded cellulose 26.9 Glycerol 6.8 Sodium Alginate 9.6 CaCO 13.2 Potassium citrate 3.9 MgCO 39.6

EXAMPLE 16 2.04 parts of glycerol and 1.17 parts of potassium citrate were dissolved in 75 mls. of water. 2.88 parts 10- cust bean gum were then added to the solution and stirred for 15 minutes. 8.07 parts of thermally degraded cellulose, 12.66 parts magnesium carbonate and 3.18 parts powdered chalk were mixed together in the dry state then added to the previous-mixture. The whole was stirred for 1 hour.

Film material was made by spreading the slurry at 0.02 inches on glass plate and left to dry. The film material was humidified and shredded. Ten cigarettes were hand rolled with Imperial Verge paper.

14 1.1 g. cigarettes gave 10 standard puffs. The smoke was mild to taste. Dry weight composition:

Thermally degraded cellulose 26.9 Glycerol 6.8 Locust Bean Gum 9.6 CaCO 10.6 Potassium Citrate 3.9 MgCO 42.2

EXAMPLE 17 2.04 parts glycerol and 1.17 parts potassium citrate were dissolved in mls. of water. 2.88 parts methyl cellulose were then added to the solution and stirred for 15 minutes. 8.07 parts thermally degraded cellulose; 12.66 parts magnesium carbonate and 3.18 parts powdered chalk were mixed together in the dry state, then added to the previous mixture. The whole was stirred for 1 hour.

1.1 g. cigarettes gave 11 standard puffs. The smoke was mild to taste.

Dry weight composition:

- v Thermally degraded cellulose 26.9 Glycerol 6.8 Methyl Cellulose 9.6 CaCO 10.6 Potassium Citrate 3.9 MgCO 42.2

EXAMPLE 18 2.04 parts glycerol and 1.17 parts potassium citrate were dissolved in 150 mls. of water. 2.88 parts SCMC were then added to the solution and stirred for 15 minutes. 8.07 parts thermally degraded cellulose, 5.76 parts ferrous sulphate and 10.08 parts magnesium carbonate were mixed together in the dry state, then added to the previous mixture. The whole was stirred for 1 hour.

Film material was made by spreading the slurry at 0.02 inches on glass platesand. left to dry. The film material was humidified and shredded. Ten cigarettes were hand rolled with Imperial Verge paper.

1.1 g. cigarettes gave 11 standard puffs. The smoke was mild to taste Dry weight composition:

Thermally degraded cellulose 26.9 Glycerol 6.8 Potassium citrate 3.9 SCMC 9.6 FeSO, 19.2 MgCO; 33.6

EXAMPLE 19 2.04 parts glycerol and 1.17 parts potassium citrate were dissolved in 150 mls. of water. 2.88 parts SCMC were then added to the solution and stirred for 15 minutes. 8.07 parts thermally degraded cellulose, 10.08 parts aluminium hydroxide and 5.76 parts powdered chalk were mixed together in the dry state, then added to the previous mixture. The whole was stirred for 1 hour.

1.1 g. cigarettes gave 12 standard puffs. The smoke was mild to taste.

Dry weight composition:

Thermally degraded cellulose 26.9 Glycerol 6.8 Potassium citrate 3.9 SCMC 9.6 CaCO 19.2 AL(OH) 33.6

EXAMPLE 20 2.04 parts glycerol and 1.17 parts potassium citrate were dissolved in 150 mls. of water. 2.88 parts SCMC were then added to the solution and stirred for 15 minutes. 8.07 parts thermally degraded cellulose, 7.56 parts magnesium carbonate and 8.16 parts titanium dioxide were mixed together in the dry state, then added to the previous mixture. The whole was stirred for 1 hour.

1.1 g. cigarettes gave standard puffs. The smoke was mild to taste.

Dry weight composition:

Thermally degraded cellulose 2 Glycerol SCMC Potassium citrate Titanium dioxide Magnesium carbonate EXAMPLE 21 2.04 parts glycerol and 1.17 parts potassium citrate were dissolved in 150 mls. of water. 2.88 parts SCMC were then added to the solution and stirred for minutes. 8.07 parts thermally degraded cellulose, 11.28 parts magnesium carbonate and 4.56 parts aluminosilicate were mixed together in the dry state, then added to the previous mixture. The whole was stirred for 1 hour.

1.1 g. cigarettes gave 12 standard puffs. The smoke was mild to taste.

Dry weight composition:

Thermally degraded cellulose 2 Glycerol SCMC Potassium citrate Aluminosilicate Magnesium carbonate What we claim is:

l. A smoking mixture in fabricated form comprising a. as smoke-producing fuel, a particulate solid thermally degraded carbohydrate tobacco substitute which is obtained by subjecting a carbohydrate to a catalysed degradation process at a temperature of at least 100C until the weight of the degraded material is less than 90 percent of the dry weight of the original carbohydrate,

b. a harmless filler and 0. sufficient binder to enable the mixture to be fabricated,

said filler being harmless on pyrolysis and present in a proportion of 40 to 65 percent by weight of the mixture and being selected from salts wherein the anion comprises formate, oxalate, citrate, tartrate, silicate, carbonate, chloride, sulphate, phosphate, borate, oxide, dioxide or aluminate and the cation comprises sodium, potassium, calcium, magnesium, iron or titanium, the combination of cations and anions in the filler being selected to impart a burning rate correlated to a puff number of 8-12 of a machine-made standard Class B British cigarette containing 1.1 g. tobacco, where each puff is of 25 ml. volume in two seconds, followed by a 58 second rest or smouldering period and where the mm. cigarette is smoked to a butt length of 20 2. A smoking mixture as claimed in claim 1 wherein the filler comprises calcium carbonate, calcium borate, sodium borate, calcium orthophosphate, calcium oxalate, iron sulphate, titanium dioxide, magnesium carbonate, sodium aluminosilicate, bentonite or aluminium hydroxide.

3. Atsrnoking mixture as claimed in claim 1 wherein the harmless filler comprises a mixture of calcium carbonate and a member of the group consisting of magnesite, light basic magnesium carbonate, calcium orthophosphate and calcium sulphate, and the binder is carboxymethyl cellulose or salt thereof.

4. A smoking mixture as claimed in claim 1 comprising a plasticiser/humectant in addition to the binder.

5. A smoking mixture as claimed in claim 4 wherein the plasticiser/humectant comprises glycerol, ethylene glycol or polyethylene glycol.

6. A smoking mixture as claimed in claim 1 wherein the binder comprises carboxymethyl cellulose and its salts, other carboxylated carbohydrates, natural gum, guar gum, locust bean gum or cellulose ethers.

7. A method of manufacturing a smoking mixture according to claim 1 comprising preselecting a particulate solid thermally degraded carbohydrate tobacco substitute as defined in claim 1 as smoke-producing fuel and preselecting the proportion by weight of said thermally degraded carbohydrate tobacco substitute to be incorporated in the smoking mixture, admixing said combustible material with a predetermined amount of binder and a harmless filler selected from salts wherein the anion comprises formate, oxalate, citrate, tartrate, silicate, carbonate, chloride, sulphate, phosphate, borate, oxide, dioxide or aluminate and the cation comprises sodium, potassium, calcium, magnesium, iron or titanium, the filler being harmless on pyrolysis and present in a proportion of 40 to 65 percent by weight of the mixture, and the combination anions and cations in the filler being sufficient to impart a burning rate correlated to a puff number of 8-l 2 of a machine-made shaped article is a film, extruded filament or tape.

9. A method as claimed in claim 7 wherein the filler comprises calcium carbonate, calcium borate, sodium borate, calcium orthophosphate, calcium oxalate, iron sulphate, titanium dioxide, magnesium aluminate, so-

dium aluminium silicate or mixture thereof.

Claims

1. A SMOKING MIXTURE IN FABRICATED FORM COMPRISING A. AS SMOKE-PRODUCING FUEL, A PARTICULATE SOLID THERMALLY DEGRADED CARBOHYDRATE TOBACCO SUBSTITUTE WHICH IS OBTAINED BY SUBJECTING A CARBOHYDRATE TO A CATALYSED DEGRADATION PROCESS AT A TEMPERATURE OF AT LEAST 100*C UNTIL THE WEIGHT OF THE DEGRADED MATERIAL IS LESS THAN 90 PERCENT OF THE DRY WEIGHT OF THE ORIGINAL CARBOHYDRATE, B. A HARMLESS FILLER AND C. SUFFICIENT BINDER TO ENABLE THE MIXTURE TO BE FABRICATED, SAID FILLER BEING HARMLESS ON PYROLYSIS AND PRESENT IN A PROPORTION OF 40 TO 65 PERCENT BY WEIGHT OF THE MIXTURE AND BEING SELECTED FROM SALTS WHEREIN THE ANION COMPRISES FORMATE, OXALATE, CITRATE, TARTRATE, SILICATE, CARBONATE, CHLORIDE, SULPHATE, PHOSPHATE, BORATE, OXIDE, DIOXIDE OR ALUMINATE AND THE CATION COMPRISES SODIUM, POTASSIUM, CALCIUM, MAGNESIUM, IRON OR TITANIUM, THE COMBINATION OF CATIONS AND ANIONS IN THE FILLER BEING SELECTED TO IMPART A BURNING RATE CORRELATED TO A PUFF NUMBER OF 8-12 OF A MACHINE-MADE STANDARD CLASS B BRITISH CIGARETTE CONTAINING 1.1 TOBACCO, WHERE EACH PUFF IS OF 25 ML. VOLUME IN TWO SECONDS, FOLLOWED BY A 58 SECOND REST OR SMOULDERING PERIOD AND WHERE THE 70 MM. CIGARETTE IS SMOKED TO A BUTT LENGTH OF 20 MM.

2. A smoking mixture as claimed in claim 1 wherein the filler comprises calcium carbonate, calcium borate, sodium borate, calcium orthophosphate, calcium oxalate, iron sulphate, titanium dioxide, magnesium carbonate, sodium aluminosilicate, bentonite or aluminium hydroxide.

3. A smoking mixture as claimed in claim 1 wherein the filler harmless comprises a mixture of calcium carbonate and a member of the group consisting of magnesite, light basic magnesium carbonate, calcium orthophosphate and calcium sulphate, and the binder is carboxymethyl cellulose or salt thereof.

7. A method of manufacturing a smoking mixture according to claim 1 comprising preselecting a particulate solid thermally degraded carbohydrate tobacco substitute as defined in claim 1 as smoke-producing fuel and preselecting the proportion by weight of said thermally degraded carbohydrate tobacco substitute to be incorporated in the smoking mixture, admixing said combustible material with a predetermined amount of binder and a harmless filler selected from salts wherein the anion comprises formate, oxalate, citrate, tartrate, silicate, carbonate, chloride, sulphate, phosphate, borate, oxide, dioxide or aluminate and the cation comprises sodium, potassium, calcium, magnesium, iron or titanium, the filler being harmless on pyrolysis and present in a proportion of 40 to 65 percent by weight of the mixture, and the combination anions and cations in the filler being sufficient to impart a burning rate correlated to a puff number of 8-12 of a machine-made standard Class B British cigarette containing 1.1 g. tobacco, where each puff is of 25 ml. volume in two seconds, followed by a 58 second rest or smouldering period and where the 70 mm. cigarette is smoked to a butt length of 20 mm., and finally fabricating a shaped article of the mixture utilising a binder.

8. A method as claimed in claim 7 wherein the shaped article is a film, extruded filament or tape.

9. A method as claimed in claim 7 wherein the filler comprises calcium carbonate, calcium borate, sodium borate, calcium orthophosphate, calcium oxalate, iron sulphate, titanium dioxide, magnesium aluminate, sodium aluminium silicate or mixture thereof.