AU601977B2 - Improvements relating to smoking articles - Google Patents

Description

i COMMONWEALT. OF AUSTRALIA 97 7 PATENTS ACT 1952 C )M P T. Frp

SPECIFICATION

C 0 P LE T FOR OFFICE USE: 7 2 7 Class Int.Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority: Related Art: *1ame of Applicant: 'Address of Applicant: 4 1 BRITISH-AMERICAN TOBACCO COMPANY LIMITED WESTMINSTER HOUSE, 7 MILLBANK, LONDON SWIP 3JE,

ENGLAND

Actual Inventor: COLIN GREIG Address for Service: SHELSTON WATERS, 55 Clarence Street, Sydney ,Complete Specification for the Invention entitled: "IMPROVEMENTS RELATING TO SMOKING ARTICLES" The following statement is a full description of this invention, including the best method of performing it known to me/us:- 1 It i r: -la-

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"IMPROVEMENTS RELATIN' TO SMOKING ARTICLES" flrttr

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rl C C i CLIC .O The invention the subject of this application relates to smoking articles.

Proposals have been made in the patents literature for simulated smoking articles comprising a tubular casing and a body of carrier material disposed within the casing.

According to these proposals the carrier material is treated with an agent which volatilises when air is drawn through the casing. Proposals of this nature are contained in Unit..d States Patcnt Specifications Nos. 2,721,551; 2,860,638 and 3,404,692, South African Patent Specification No. 697737 and United Kingdom Patent Specification No.

2 032 244. According to US 2,860,638 (Bartolomeo), ZA 697737 (Zwarenstein) and GB 2 032 244 (Ray) the volatile agent with which the carrier material is treated is or can be nicotine.

Proposals have also been made in the patents literature for means for the enhancement of the mainstream smoke nicotine delivery level of cigarettes. It has been proposed in United States Patent Specification No. 3,422,819 to treat the paper wrapper of a cigarette with a nicotine salt, the cigarette being provided with a second, outer wrapper in order to prevent the wrapper treated with the nicotine salt coming into contact with the smoker's lips. It is the teaching of United Kingdom Patent Specification No. 1,032,330 to contact a particulate ion exchange resin with nicotine and to 4~ 1, t p.- -2incorporate the resultant nicotine-ion exchange resin complex in cigarette filters. According to the disclosure of United States Patent Specification No.

3,584,630, nicotine is adsorbed on a finely divided weak adsorbent which is then incorporated in tobacco or in tobacco smoke filters. The preferred adsorbents in US 3,584,630 are types of carbon black.

In European Patent Specification No. 174 645 there are disclosed simulated smoking articles comprising a D short combustible carbonaceous fuel element and a li substrate bearing an aerosol forming substance, the fuel element and the substrate both being in contact with heat conducting means. Nicotine may be carried on the substrate.

It is an object of the present invention to provide in an improved manner a cigarette, or similar smoking article, in the smoking of which the nicotine level of a the smoke delivered from the cigarette is greater than ~the nicotine level of the smoke at exit from the down- S O stream end of the smoking material rod of the cigarette.

:i It is a further object of the present invention to to-tar ratio of the mainstream smoke of a smoking article may be increased independently of the nicotine content of the smoking material of the smoking article.

The present invention provides a smoking article comprising a rod of smoking material and a nicotine r ,r release element attached toQsaid rod at a mouth end of said rosaid element comprising a smoke pervious body of a polymeric material composed of carbon and hydrogen atoms only adselected from the group comprising polyethylene, polypropylene and polystyrene, the suirface of said polymeric material being hydrophobic and being without chem4.cal functionality, said body carrying nicotine in direct contact therewith, whereby when said smoking article is smoked, smoke o~ooa:drawn through said element from said rod causes release into 0* 0 I I 1O the smoke of nicotine from said body.

The smoking material preferably comprises or consists of tobacco, which tobacco is suitably in conventional cut filler o o~o form. The tobacco can be of air-cured, flue-cured, Burley or Oriental type, or may be a blend of any of these. A proportion of the tobacco may be tobacco which has been subjected to an expansion process. It is also possible for tne smoking a material to comprise a reconstituted tobacco product or a a a tobacco substitute material. Preferably the smoking material comprises a nicotine source.

The rod of smoking material may comprise a passage extended to the region of the downstream end of the rod, whereby, during the smoking of the smoking article, hot smoke is conveyed to the downstream end of the rod. For further details of smoking articles comprising such a passage reference may be had toi United Kingdom Patent Specification No. 2,149,287A.

The polymeric material may be of a fibrous, cellular or particulate constitution and the body thnereof is suitably of cylindrical conformation.

4 0 44 4 The nicotine carrying body of polymeric material may abut at the upstream and/or downstream end thereof a filter plug of, for example, cellulose acetate. Both upstream and downstreams filter plugs are suitably employed if the polymeric material is in particulate form.

The polymeric material of the nicotine carrying body is advantageously polyethylene. The use of polyethylene, polypropylene and polystyrene materials provides distinct S advantages over prior art proposals. These materials may be '140 made in close and continuous conformity to predetermined 4. physical and chemical specifications. These materials are also 44 readily susceptible to accurate shaping by being, for example, extruded to provide rod from which cylindrical plugs may be cut. Such plugs are self-sustaining, that is to say, the plugs do not require for dimensional stability to be wrapped in a plugwrap. Furthermore, these materials are inexpensive and are clean to use in cigarette manufacturing processes.

The nicotine carried by the body of polymeric material may be free nicotine, a nicotine salt or a nicotine derivative. In addition to nicotine, there may be applied to the body of polymeric material one or more volatile flavour agents, menthol being one such agent.

If the nicotine of the nicotine release element is free nicotine, a further smoke pervious element, which further element carries an acid, may be located adjacent to the nicotine release element. By use of such an arrangement, with suitable relative nicotine and acid loadings, there may be formed kduring the smoking of the smoking article a salt having 444 *e e

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a pH value in the range of approximately 5 to 7. The resultant change in the pH of the mainstream smoke, from what might otherwise be a value above 7, serves to enhance the sensory characteristics of the smoke. Suitable acids for this pH control purpose include lactic acid and tartaric acid.

Whereas it is possible to load a pH controlling acid on the nicotine release element at the same location thereon as the nicotine, it has been found that with such arrangement the nicotine level in the mainstream smoke is not very much higher 1 0 than that of the smoke at exit from the downstream end of the S smoking material rod. A significantly more effective N arrangement is for the acid to be loaded on a separate element located adjacent the nicotine release element. The separate, acid carrying element is suitably located to the side of the nicotine release element further from the

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-6material rod. In another arrangement the nicotine release element and the acid carrying element are disposed at the same longitudinal zone of the smoking article with the elements occupying respective portions of the transverse cross-section of the zone. When this arrangement is adopted there is preferably located between the two elements a separating partition formed of a vapour impervious material.

Cigarettes in accordance with the present invention are shown, by way of example, in the drawing hereof.

The cigarette shown in the Figure 1, which is generally designated by reference numeral 1, comprises I a 64 mm cigarette rod 2, a mouth end assembly 3 and a I tipping wrapper 4 which serves to interattach the rod 2 and the assembly 3. The rod 2 comprises as smoking i material a low nicotine, flue-cured, cut tobacco filler 5 and a cigarette paper wrapper 6. The mouth end assembly 3 comprises a cylindrical plug 7 of open cell polyethylene, which has been impregnated with 3 to 10 mg Do of free nicotine, and a cylindrical filter plug 8 of cellulose acetate. As may be seen from the drawing, the plug 7, which constitutes a nicotine release element, is disposed intermediate and in abutment with the cigarette rod 2 and the filter plug 8.

When the cigarette 1 is smoked, tobacco smoke from the rod 2 passes through the plug 7 and thereby causes nicotine in the plug 7 to volatilise. The nicotine l.J i i ti -7vapour and tobacco smoke then pass through the filter plug 8. In this manner the nicotine delivery level of the mainstream smoke is enhanced in relation to the level that would obtain if the cigarette did not include the nicotine loaded plug 7.

The tipping wrapper 4 may be perforated at the region of the plug 7 and/or the plug 8 to permit the ingress of ventilation air. Preferentially, if ventilation perforations are present, the perforations should be located at the region of the plug 8.

In Figure 2 the cigarette 1' there depicted has I t, similar reference numerals to those of Figure 1 for similar parts. The cigarette 1' of Figure 2 is of the same construction as the cigarette 1 of Figure 1 except that the mouth end assembly 3 comprises, in place of a filter plug, a further cylindrical plug of open cell polyethylene designated The plug which is of the same length and physical constitution as the plug 7, is impregnated with lactic acid.

It was found that when the plug 7 of the Figure 2 cigarette was impregnated with 10 mg of free nicotine a 4and the plug 8' thereof was impregnated with 10 mg t o of lactic acid, the nicotine level of the mainstream smoke flowing from the plug 8' during the smoking of the cigarette was, as measured over nine machine smoked puffs, enhanced by about 75% as compared to a plain, i.e. untipped, control cigarette, having a cigarette i ji:: 1 -8rod the same as that of the cigarette of Figure 2. The nicotine in the mainstream smoke as a percentage of the particulate matter (water and nicotine free) was 13, whereas that for the control cigarette it was only 5.8.

A similar mainstream smoke nicotine level enhancement to that exhibited by the Figure 2 cigarette would be expected from the Figure 1 cigarette if the plug 7 thereof was loaded with 10 mg of nicotine.

In a further experiment puff-by-puff nicotine SjtO deliveries were measured for cigarettes each comprising a tobacco rod from a standard British middle tar

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cigarette, a 10 mm long cellulose acetate filter element in abutment with the tobacco rod and a 10 mm long nicotine release element in abutment with the filter element. The nicotine release element comprised a plug of polyethylene impregnated with 10.8 mg of nicotine. The nicotine delivery values for these cigarettes were compared with those for control cigarettes comprising tobacco rods of t- above mentioned standard middle tar type and 10 mm long cellulose acetate filter elements as per those of the experimental cigarettes.

It was determined from this experiment that the average nicotine delivery enhancement of the experimental cigarettes comprising the nicotine release element as compared with the control cigarettes decreased from 0.10 mg for Puff 1 to 0.07 mg for the final puff, Puff 7.

Claims (6)

1. 2. A smoking article as claimed in Claim 1, wherein said nicotine is free nicotine.
2. 3. A smoking article as claimed in Claim 1 or Claim 2, wherein said smoking material consists, at least predominately, of tobacco and wherein in the smoking of said article the nicotine delivered in the mainstream i smoke is not more than fifty percent greater than t the nicotine delivered in the smoking of a plain control cigarette.
3. 4. A smoking article as claimed in any one of the preceding claims, said smoking article having a mainstream nicotine delivery in a range of 0.05 mg to 3.00 mg. A smoking article as claimed in any one of the preceding claims, in the smoking of which the ratio of the nicotine delivered in the mainstream smoke to the articulate matter, water and nicotine free, delivered in 6 articulate 10 said mainstream smoke is greater than said ratio for a plain control cigarette.
4. 6. A smoking article as claimed in any one of the preceding claims, and further comprising, at the mouth end region of said smoking article, an acid which is reactable with said nicotine to provide a salt.
5. 7. A smoking article as claimed in Claim 6, wherein said acid is disposed at a location other than the location of said nicotine. S8. A smoking article as claimed in any one of the preceding claims, said article being a cigarette.
6. 9. A smoking article as claimed in any one of the preceding claims, wherein said smoking material comprises i cut tobacco. A cigarette substantially as hereinbefore described *with reference to Figure 1 or Figure 2 of the drawing d hereof. DATED this day of 1990 BRITISH-AMERICAN TOBACCO COMPANY LIMITED Attorney: LEON K. ALLEN Fellow Institute of Patent Attorneys of Australia of SHELSTON WATERS t 1