FR2652237A1 - Improvement relating to smokers' articles - Google Patents

Abstract

The present invention relates to a cigarette having the shape of an elongate rod of uniform cross section over its entire length, the rod being composed of a tobacco filling, a cigarette paper wrapper and a filter, characterised in that the cigarette paper wrapper is composed of a first paper surrounding the tobacco filling, and a second paper covering the first and having a basic weight in gm<-2> which is greater than that of the first cigarette paper, and in that the rod has an external circumference of small dimension. This cigarette has been tested to determine the smoke components with a machine (7).

Description

The invention relates to cigarettes and similar smoking articles.

In British Patent Specification No. 2,175,789A it is disclosed that cigarettes having a circumference in the range of 10-19 inm and a free burn rate of the cigarette rod of 25-50 mg mine exhibit a production of weaker side current than conventional cigarettes.

Cigarettes comprising cigarette papers having a viscous flow air permeability of less than 3 Coresta units and a Do / t ratio of 0.08 to 0.65 are described in British Patent Specification No. 2,094,130A. cm sec ~ 1, where Do is the diffusion coefficient of oxygen through nitrogen in the paper and t is the thickness of the cigarette paper. Such cigarettes exhibit low production of total particulate matter and nicotine in sidestream smoke.

Another approach to achieve low component production in sidestream smoke from cigarettes is to use cigarette papers comprising one or more sidestream reducing compounds. Thus, for example, in UK Patent Specification No. 2,139,869A it is disclosed that the total particulate matter in sidestream smoke which emanates from the lit tip of cigarettes while being smoked can be reduced by at least 30%, whether the paper comprises one or more, preferably a plurality, of the components of the group consisting of lithium hydroxide, aluminum hydroxide, calcium hydroxide, potassium formate, sodium formate and sodium acetate.

Another example of the use of sidestream reducing compounds is described in U.S. Patent Specification No. 4,231,377, according to which the teaching of magnesium oxide and an adjuvant salt in combination are incorporated into cigarette paper.

The object of the present invention is to provide improved cigarettes with low side current or similar low side current smoking particles.

The invention provides a smoking article comprising a rod of smoking material, the rod comprising a smoking material and a paper casing surrounding the smoking material, the circumference of the rod not exceeding 20mm and the casing being in one piece. material comprising a sidestream reducing compound, the material being such that when providing a shell of a rod of smoking material of conventional cigarette circumference there is a reduction of at least 30% in particulate matter, over a base free of water and nicotine, secondary stream compared to a control rod of the same conventional cigarette circumference and including conventional cigarette paper.

The sidestream reducing compound is effective in reducing visible sidestream components without effecting a marked reduction, if any, in the gas phase of the sidestream smoke. The components used, alone or in combination, to reduce the side current are: aluminum hydroxide, calcium hydroxide, lithium hydroxide, magnesium hydroxide, magnesium oxide, alumina and attapulgite clay. Other compounds that can be used as side current reducing compounds are described in US Patent Specification No. 4,461,311, to which we refer.

Suitably, the material of the envelopes of the smoking articles according to the present invention is paper. Water insoluble sidestream reducing compounds are added as a powder as a paper filler and supplied during the wrapping paper material manufacturing process. Water soluble compounds reducing the sidestream are preferably added in aqueous solution applied to the shell material.

The smoking material of smoking articles according to the present invention comprises or preferably consists of cut tobacco, a part of this tobacco may be expanded tobacco. The smoking material may include reconstituted tobacco or a material which is a tobacco substitute.

The length of the rod of smoking material is preferably at least 60mm and the rod preferably produces at least six puffs and more, preferably less than seven puffs when smoked under standard smoking machine conditions. The rod is of uniform cross-sectional shape and dimensions along the length of the rod. If the rod is of circular section, the circumference of the rod is as small as 10 mm for example, but is preferably not less than 12.5 mm.

Advantageously, the circumference of the rod of smoking material is not more than 19 mm, and more preferably it is not smaller than 18 mm.

Cigarettes according to the present invention preferably include a filter, or mouthpiece, attached to one end of the rod of smoking material.

The envelopes of the smoking articles according to the present invention are preferably of low permeability, their permeability not exceeding, for example, 20 Coresta units, and more preferably not exceeding 12 Coresta units.

Examples according to the invention are now the object of description in order to provide a better understanding.

EXAMPLE 1
A cigarette was produced consisting of a cigarette rod with a circumference of 20 mm and a length of 64 mm, and a cellulose acetate filter of a length of 20 mm attached to the rod by means of the tip shell. The stem includes a filling of cut tobacco with a density of 240 mg cl ~ 3, this filling was wrapped in a cigarette paper surrounding it having an air permeability of 19 Coresta units and a density of 45 g m-2, The cigarette paper contained 23% chalk, 8% magnesium hydroxide and 2% sodium acetate, when these cigarettes had been smoked under standard smoking machine conditions, i.e. a 35cc puff duration of 2 seconds every two minutes, until an 8 mm long cigarette tip remains, the total production of sidestream particulate matter, on a free basis. water and nicotine, was 9.2 mg, the total production of sidestream carbon monoxide was 34.3 mg. The average number of puffs of these cigarettes was 8.9.

SORTING EXAMPLE
Cigarettes were produced consisting of a cigarette rod with a circumference of 20 mm and a length of 64 mm, and a cellulose acetate filter of a length of 20 mm attached to the rod by means of the tip shell. The stem comprises a 287 mg cl ~ 3 density cut tobacco filling, the cigarette paper wraps having an air permeability of 11 Coresta units and a density of 43 g m2. The cigarette paper contained 19.7% chalk, 5% magnesium oxide and 6.7% tripotassium citrate (expressed as% citric acid anhydride) .These cigarettes smoked under standard smoking machine conditions, had a total production of sidestream particulate matter, on a water and nicotine free basis, was 13.3 mg, the total sidestream carbon monoxide production was 36.8 mg. The average number of puffs of these cigarettes was 8.3.

EXAMPLE iri
Cigarettes consisting of a cigarette rod with a circumference of 17 mm and a length of 70 mm, and a cellulose acetate filter of a length of 27 mm were produced. The density of the cut tobacco filling of the cigarette stems was 293 mg cl ~ 3, the cigarette paper wrappers having an air permeability of 26 Coresta units and a density of 26 gm ~ 2. The cigarette paper did not contain a sidestream reducing compound.Some of these cigarettes were overwrapped with a second cigarette paper with a permeability of 15 Coresta units and a basis weight of 50 gm-2 The second paper consisted of 4.5% chalk, 24.3 t of magnesium hydroxide and 3.6% of sodium acetate. When these cigarettes were smoked under standard smoking machine conditions, it was determined that each had a total production of sidestream particulate matter, on a water and nicotine free basis, of 8.3 mg, the production Total sidestream carbon monoxide and nicotine were 39.1 mg and 1.1 mg, respectively. The average puff count of these cigarettes was 12. When the non-overwrapped cigarettes were smoked under the same conditions the total production of sidestream particulate matter, on a water and nicotine, carbon monoxide and nicotine free basis. secondary current was 20.7 mg, 45 mg and 2.7 mg, respectively.

Two types of control cigarettes were smoked, each having a 54mm long cigarette stalk of conventional 24.75mm circumference. The first type of control cigarette included an envelope cigarette paper having an air permeability of 47 units.
Coresta and a density of 25 g m-2, Cigarette paper contained 26% chalk and 0.8% tri-potassium citrate.

When the first types of control cigarettes were smoked under standard smoking machine conditions, the total sidestream nicotine production was 4.9 mg. As noted above, the total sidestream nicotine production for the 17mm non-overwrapped cigarettes was 2.7 mg. It is therefore observed that with cigarettes comprising envelopes made of conventional cigarette paper, a reduction in the cigarette stem circumference to an unconventional value of 17 mm, compared with a conventional value of 24.75 mm, reduces the size of the cigarette. 45% sidestream nicotine.

The second type of control cigarette comprised a wrapper of cigarette paper of the same type of paper as used to overwrap the 17mm overwrapped cigarettes mentioned above. When these cigarettes were smoked under standard conditions, they were found to provide a total sidestream nicotine production of 2.5 mg. When this nicotine production of sidestream is compared with that of the first type of control cigarette, it can be observed that the substitution of the cigarette paper reducing the sidestream in place of the conventional cigarette paper of the first type of control cigarette produced a 49% reduction effect of sidestream nicotine production.

From the above it can be expected that by combining in a single cigarette the two nicotine reducing characteristics, namely the reduction of the cigarette circumference from 24.75 mm to 17 mm and the substitution of conventional cigarette paper with a paper. With a cigarette reducing the secondary current, the total production of nicotine from the secondary current is reduced to 28% of that of a conventional cigarette comprising neither of the two characteristics, this conventional cigarette being represented by the first type of control cigarette. In point of view, the 17mm circumference over-wrapped cigarettes, which of course include each of the two sidestream reducing features, produce a reduction in the total sidestream nicotine production to a value, namely 1.1 mg, which is 22.5% of that of the first type of control cigarette. Therefore, 17mm circumference over-wrapped cigarettes exhibit a synergistic effect of sidestream nicotine reduction.

EXAMPLE IV
Cigarettes consisting of a cigarette rod with a circumference of 24.75 min and a length of 64 min, and a cellulose acetate filter of a length of 20 min were produced. The density of the cut tobacco filling of the cigarette stems was 279 mg cl ~ 3, the cigarette paper envelopes having an air permeability of 47 Coresta units and a density of 25 g The cigarette paper contained 26% a filling of calcium carbonate and 0.18% of a combustion additive consisting of a mixture of potassium citrate and sodium citrate, expressed as a percentage of citric acid. These cigarettes were called A.

Second cigarettes, referred to as B cigarettes were produced, B cigarettes being in all respects identical to A cigarettes, except that the cigarette stems of B cigarettes were made of secondary current reducing paper, with a permeability of 19 Coresta units and a density of 44.8 g m2. The sidestream reducing paper comprised 8.2% magnesium hydroxide, 21.8% calcium carbonate and 2.02% sodium acetate.

C cigarettes were produced identical in all respects to A cigarettes except that the C cigarettes had a circumference of 17 mm.

D cigarettes were produced identical in all respects to C cigarettes except that the stalk wraps of D cigarettes were of the same paper as those of the stalk wraps of cigarettes of B cigarettes.
D were the cigarettes according to the present invention.

Cigarettes A through D were smoked under standard smoking machine conditions and measurements of the total secondary stream particulate matter production were made for each cigarette, on a water and nicotine free basis (PMWNF). total nicotine alkaloids (TNA) and carbon monoxide (CO). The measured values were given in table 1.

The predicted values shown in Table 1 for cigarettes
D were calculated From the measured values for cigarettes A to C. Hence, for example, the predicted value of
PMWNF for D cigarettes is calculated as
18.5 mg x 15.8 / 36.5 = 8 mg.

The measured value of PMWNF of the D cigarettes was 7 mg.

Therefore, it has been observed that by effecting both the reduction of the diameter of the cigarette and providing a shroud reducing the secondary current, thereby proceeding according to the present invention, there is a synergistic reducing effect of PMWNF. secondary current. As also shown in Table 1, the cigarettes D according to the invention also show synergistic reductions concerning the TNA and the CO of the secondary stream.

The average number of puffs of D cigarettes was 10.8.

SE 1
PMWNF TNA CO Cigarette
mg mg mg
A 36.5 7.72 62.1
B 15.8 5.53 60.1
C 18.5 3.26 42.4
D 8.0 2.30 41.1
planned
D 7.0 2.17 36.1
measured
EXAMPLE V
E cigarettes were produced consisting of a cigarette rod with a circumference of 24.75 mm and a length of 64 minutes, and a cellulose acetate filter of a length of 20 mm. The density of the filling of cut tobacco from the stems of cigarettes, with a filling containing 12% by weight of expanded tobacco according to the DIET method, was 252 mg cm3 The shells of the stems of E cigarettes were of the same conventional cigarette paper than that used for the A cigarettes of Example IV.

F cigarettes had been produced which were the same in all respects as E cigarettes except for the use in the F cigarettes of cigarette paper having an air permeability of 18 Coresta units and a specific gravity of 47.4 g m'2 and comprising 33.3% magnesium hydroxide, 5.3% calcium carbonate, 5.3% potassium acetate and 1.1% sodium acetate.

G cigarettes were produced, being in all respects identical to E cigarettes, except that the circumference was 17 mm and the cut tobacco filling contained 40% by weight of DI ET expanded tobacco, the density of the filling was 224 mg cl ~ 3.

The H cigarettes were identical to the G cigarettes in all respects, except that the cigarette stems of the H cigarettes were of the same sidestream reducing paper as the F cigarettes. The H cigarettes were cigarettes according to the present invention. .

Cigarettes E through H were smoked under standard smoking machine conditions and measurements of total secondary stream particulate matter production were made for each cigarette of PMWNF, TNA and CO. The measured values were given in Table 2. The predicted values for H cigarettes were calculated in the same way as above for D cigarettes.

It was observed in Table 2 that the H cigarettes according to the invention exhibited a synergistic reduction effect of
PMWNF, TNA and CO secondary stream. H cigarettes also exhibit a synergistic reduction for sidestream carbon dioxide.

The average number of puffs of H cigarettes was 6.8.

TABLE 2
PMWNF TNA CO Cigarette
mg mg
E 25.6 5.45 58.6
F 11.48 3.79 51.5
G 14.6 2.40 30.4
H 6.7 1.68 26.7
planned
H 5.3 1.15 25.9
measured
EXAMPLE VIEW
Cigarettes I consisting of a cigarette rod with a circumference of 24.75 mm and a length of 64 mm, and a cellulose acetate filter of a length of 20 mm. The density of the filling of tobacco cut from the cigarette stems was 291 mg cm3. The stalk wraps of cigarettes I were of the same conventional cigarette paper as that used for the A cigarettes of Example IV.

J cigarettes had been produced which were the same in all respects as I cigarettes except for the use in J cigarettes of cigarette paper having an air permeability of 5 Coresta units and a specific gravity of 45.0 g m'2 and comprising 16% attapulgite clay, 18% calcium carbonate, 11% tri-potassium citrate and 3% monoammonium phosphate.

K cigarettes were produced, being in all respects identical to I cigarettes, except that the circumference of the K cigarettes was 17 mm.

L cigarettes were identical to K cigarettes in all respects except that the shaft wraps of L cigarettes were of the same sidestream reducing paper as that of J cigarettes. L cigarettes were cigarettes according to the present invention.

Cigarettes I to L were smoked under standard smoking machine conditions and measurements of total secondary stream particulate matter production were made for each cigarette of PMWNF, TNA and CO, the measured values were given in Table 3.

It is observed in Table 3 that the cigarettes L according to the invention exhibited a synergistic reduction effect of the TNA and of the CO of the secondary current.

The average number of puffs of L cigarettes was 13.0.

TABLE3
PMWNF TNA CO Cigarette
mg mg mg
I 33.7 4.9 67.0
J 13.5 2.7 49.0
K 18.5 3.29 42.4
L 7.4 1.81 31.0
planned
L 9.8 1.73 25.6
measured
Figure 1 of the above schematic drawings shows the apparatus used to make determinations of the outputs of the sidestream smoke components and Figures 2-5 show a fishtail chimney forming part of the apparatus shown in Figure 1, FIGS. 23 to 5 being views of FIG. 2, taken along arrows A, B and C respectively.

The apparatus shown in Fig. 1 which has been used to perform the determinations of the above cited productions of sidestream smoke components comprises a Filtrona 302 linear smoking machine, one orifice thereof being designated by the numeral 8. At each orifice of the smoking machine 7 was disposed an open ended glass fishtail chimney which, associated with the orifice 8, is designated by the numeral 9. In FIG. 2, the dimensions a and b are respectively 410 and 80 mm. In Fig. 4, the inner dimension (diameter c) is 24mm and dimension d is 22mm. A pre-weighed filter cartridge 10 was disposed transversely on the stack 9. Reference numeral 10 'denotes a Cambridge filter cartridge used in the measurement of the component productions of the main flow.

A tube 11 extends from the upper side of the filter cartridge 10 to a gas flow meter 12, from which a tube 13 extends to a gas pump 14. A carbon monoxide analyzer 17 comprising a circulation pump internal gas (not shown) was connected to the tube 13 by inlet and outlet tubes 15, 16.

During operation of the apparatus of FIG. 1, to determine the sidestream smoke component outputs of a cigarette 18 smoked at the port 8 of the smoking machine 7, the pump 14 was adjusted to provide a flow rate of 2.0 liters per. minute through chimney 9, tube 11 and tube 13. While cigarette 18 was smoked under standard conditions at port 8, the sidestream smoke from cigarette 18 passed through chimney 9 to the cartridge. filter 10. This portion of the smoke not deposited on the cartridge 10 or on the interior walls of the chimney 9 passes into the tubes 11, 13 and a small sample of this passes through the carbon monoxide analyzer 17, by means of the inlet and outlet tubes 15, 16.

The cartridge was reweighed when the cigarette 18 from port 8 and two identical cigarettes had been smoked. From the weight thus determined, the original weight of cartridge 10 was subtracted to thereby give the total weight of particulate matter (TPM) deposited on cartridge 10. Cartridge 10 was then extracted using a extraction solvent, for example propan-2-ol. The extract thus obtained was analyzed by gas chromatography to determine the amount of nicotine and water deposited on the cartridge 10. The sum of the weights thus determined of nicotine and water was subtracted from the determined gravimetrically mentioned weight of the TPM deposited on the cartridge. cartridge 10, thereby giving the weight of PMWNF which had been deposited.

The interior of the chimney 9 was rinsed with an extraction solvent, for example propan-2-ol. A part of the extract thus obtained was analyzed by gas chromatography to determine the quantity of nicotine deposited on the cartridge 10, thereby giving the total weight of sidestream nicotine produced by the three cigarettes, which weight being divided by three for give the sidestream nicotine weight per cigarette.

The other part of the extract obtained from the flushing of the chimney 9 was analyzed by an ultraviolet technique, in which a part of the extract of the cartridge 10 obtained as mentioned above was used as standard to determine the number of
PMWNF deposited on the interior walls of the chimney 9. The weight of PMWNF thus determined was added to the weight of PMWNF as determined above, deposited on the cartridge 10, thus giving the total weight of secondary stream PMWNF produced by the three. cigarettes, which weight was divided by three to give the weight of side stream PMWNF per cigarette.

The production of CO from sidestream smoke per cigarette was determined by data obtained from Analyzer 17.

Claims (17)

CLAIMS 1- Cigarette having the shape of an elongated rod of uniform cross section over its entire length, said rod being composed of a filling of tobacco, of an envelope of cigarette paper and of a filter characterized in that said cigarette paper wrapper is composed of a first cigarette paper surrounding the tobacco filling, and a second cigarette paper covering said first cigarette paper and having a basis weight in gm -2 greater than that of said first paper cigarette, and in that said rod has a circumference of 17 mm. 2 - Cigarette according to claim 1, characterized in that the basis weight in gm 2 of said second cigarette paper is much greater than that of said first cigarette paper. 3 - Cigarette according to any one of the preceding claims, characterized in that said second cigarette paper has a unit air permeability Coresta which is different from that of said first cigarette paper. 4 - Cigarette according to claim 3, characterized in that said second cigarette paper has an air permeability in Coresta unit which is widely different from that of said first cigarette paper. 5 - Cigarette according to any one of the preceding claims, characterized in that said second cigarette paper contains solid mineral fillers. 6 - Cigarette according to any one of the preceding claims, characterized in that the tobacco filling has a density of 293 mg.cm-3. 7 - Cigarette according to any one of the preceding claims, characterized in that the filter has a length of 27 mm. 8 - Cigarette according to any one of the preceding claims, characterized in that the tobacco filling has a length of 70 mm. 9 - Cigarette according to any one of claims 5 to 8, characterized in that said solid mineral fillers comprise chalk. 10 - Cigarette according to any one of claims 5 to 9, characterized in that said solid mineral fillers comprise a material from the group formed by chalk and magnesium hydroxide. he - Cigarette according to any one of claims 5 to 10, characterized in that said solid mineral fillers are present in an amount of about 29%. 12 - Cigarette according to one of claims 10 or 11, characterized in that the solid mineral fillers comprise chalk and magnesium hydroxide. 13 - Cigarette according to Alune of claims 11 or 12, characterized in that the solid mineral fillers are present in an amount of 28.8%. 14 - Cigarette according to claim 12, characterized in that it exhibits, when smoked, a production of nicotine in the secondary stream of 1.1 mg. 15 - Cigarette according to claim 12, characterized in that it exhibits, when smoked, a production of nicotine in the secondary stream which is 22.5% of that of a cigarette having a usual circumference of 24.75 mm wrapped in the usual manner in an envelope of conventional cigarette paper. 16 - Cigarette having the shape of an elongated rod of uniform cross section over its entire length, said rod being composed of a tobacco filling, of a casing of cigarette paper and of a filter characterized in that said casing cigarette paper is composed of a first cigarette paper surrounding the tobacco filling, and a second cigarette paper covering said first cigarette paper and having a basis weight in gm -2 greater than that of said first cigarette paper. cigarette, and in that, said rod has an outer circumference which is not less than 12.5 mm and not exceeding 20 mm. 17 - Cigarette according to claim 16, characterized in that said elongated rod has a circumference which does not exceed approximately 19 mm. 18 - Cigarette according to claim 16, characterized in that said elongated rod has a circumference which is less than 18 mm. 19 - Cigarette having the shape of an elongated rod of uniform cross section over its entire length, said rod being composed of a tobacco filling, a casing of cigarette paper and a filter characterized in that said casing of cigarette paper is composed of a first cigarette paper surrounding the tobacco filling, and a second cigarette paper covering said first cigarette paper and having a basis weight in gm-2 which is much greater than that of said first cigarette paper and exceeds 26 gm-2, and in that said rod has an outer circumference of 17 mm.