Smoking article with liquid delivery material

Abstract

A smoking article (10) incorporates a liquid release component of a sustained release liquid delivery material (20), the liquid delivery material comprising a closed matrix structure having a polymer matrix defining a plurality of domains. A liquid composition is trapped within the domains and is releasable from the closed matrix structure upon compression of the liquid release component. The polymer matrix is formed of one or more anionic polysaccharides cross-linked by multivalent cations. A filler comprising one or more amphiphilic polysaccharides is incorporated within the polymer matrix. The one or more amphiphilic polysaccharides of the filler are selected from starch chemically modified to be amphiphilic and starch derivatives chemically modified to be amphiphilic.

Claims

1. A smoking article incorporating at least one liquid release component formed of a sustained-release liquid delivery material comprising: a closed matrix structure comprising: a polymer matrix defining a plurality of domains, wherein the polymer matrix is formed of one or more anionic polysaccharides cross-linked by multivalent cations and a filler within the polymer matrix, the filler comprising one or more amphiphilic polysaccharides; and a flavour composition that is trapped within the domains and is releasable from the closed matrix structure upon compression of the liquid release component, wherein the one or more amphiphilic polysaccharides of the filler are selected from starch chemically modified to be amphiphilic and starch derivatives chemically modified to be amphiphilic, and wherein the liquid delivery material comprises between 4 percent by weight and 15 percent by weight of the closed matrix structure and between 60 percent by weight and 90 percent by weight of the flavor composition, based on dry weight.

2. A smoking article according to claim 1 wherein the chemically modified starch includes octenyl succinic anhydride (OSA) starch.

3. A smoking article according to claim 1 wherein the amount of the filler in the closed matrix structure corresponds to between 10 percent and 30 percent by weight of the closed matrix structure, based on dry weight.

4. A smoking article according to claim 1 wherein the closed matrix structure further comprises a plasticiser.

5. A smoking article according to claim 1 wherein the one or more anionic polysaccharides in the polymer matrix include alginate.

6. A smoking article according to claim 5 wherein the alginate comprises at least 35 percent by weight guluronic acid residues.

7. A smoking article according to claim 1 wherein the amount of the anionic polysaccharide in the closed matrix structure is at least twice the amount of the amphiphilic polysaccharide, based on dry weight.

8. A smoking article according to claim 1 wherein the flavour composition comprises a flavourant mixed with one or more fats that are liquid at room temperature (22 C.).

9. A smoking article according to claim 8 wherein the flavour composition comprises menthol.

10. A smoking article according to claim 1 wherein the multivalent cations in the polymer matrix of the liquid delivery material are calcium ions.

11. A smoking article according to claim 1 wherein a concentration of multivalent cations in the closed matrix structure is highest in an outer region of the flavour release component where a degree of cross-linking is highest and decreases towards an inner core region of the flavour release component.

12. A filter for a smoking article incorporating at least one flavour release component formed of a sustained-release flavour delivery material, the sustained-release flavour delivery material comprising: a closed matrix structure defining a plurality of domains, wherein the closed matrix structure comprises a polymer matrix of one or more anionic polysaccharides cross-linked by multivalent cations and a filler within the polymer matrix, the filler comprising one or more amphiphilic polysaccharides; and a flavour composition that is trapped within the domains and is releasable from the closed matrix structure upon compression of the flavour release component, wherein the one or more amphiphilic polysaccharides of the filler are selected from starch chemically modified to be amphiphilic and starch derivatives chemically modified to be amphiphilic, and wherein the sustained-release flavour delivery material comprises between 4 percent by weight and 15 percent by weight of the closed matrix structure and between 60 percent by weight and 90 percent by weight of the flavor composition, based on dry weight.

13. A filter according to claim 12 wherein the one or more amphiphilic polysaccharides comprises octenyl succinic anhydride (OSA) starch.

14. A filter according to claim 12 wherein the amount of the filler in the closed matrix structure corresponds to between 10 percent and 30 percent by weight of the closed matrix structure, based on dry weight.

15. A filter according to claim 12 wherein the one or more anionic polysaccharides in the polymer matrix include alginate.

16. A flavour release component for a smoking article, wherein the flavour release component is formed of a flavour delivery material comprising: a closed matrix structure defining a plurality of domains, wherein the closed matrix structure comprises a polymer matrix of one or more anionic polysaccharides cross-linked by multivalent cations and a filler within the polymer matrix, the filler comprising one or more amphiphilic polysaccharides; and a flavour composition that is trapped within the domains and is releasable from the closed matrix structure upon compression of the material, wherein the one or more amphiphilic polysaccharides of the filler are selected from starch chemically modified to be amphiphilic and starch derivatives chemically modified to be amphiphilic, and wherein the flavour delivery material comprises between 4 percent by weight and 15 percent by weight of the closed matrix structure and between 60 percent by weight and 90 percent by weight of the flavor composition, based on dry weight.

17. A flavor release component according to claim 16 wherein the one or more amphiphilic polysaccharides comprises octenyl succinic anhydride (OSA) starch.

18. A flavor release component according to claim 16 wherein the amount of the filler in the closed matrix structure corresponds to between 10 percent and 30 percent by weight of the closed matrix structure, based on dry weight.

19. A flavor release component according to claim 16 wherein the one or more anionic polysaccharides in the polymer matrix include alginate.

Description

(1) The invention will be further described, by way of example only, with reference to the accompanying FIGURE in which:

(2) FIG. 1 which shows a side view of a filter cigarette according to the present invention comprising a flavour delivery material in the tobacco rod.

(3) The cigarette 10 shown in FIG. 1 comprises an elongate, cylindrical wrapped tobacco rod 12 attached at one end to an axially aligned, elongate, cylindrical filter 14. The filter 14 includes a single segment of cellulose acetate tow. The wrapped tobacco rod 12 and the filter 14 are joined in a conventional manner by tipping paper 16, which circumscribes the entire length of the filter 14 and an adjacent portion of the wrapped tobacco rod 12. To mix ambient air with mainstream smoke produced during combustion of the wrapped tobacco rod 12, a plurality of annular perforations 18 are provided through the tipping paper 16 at a location along the filter 14.

(4) A single flavour bead 20 formed of a sustained release flavour delivery material, as described above, is provided centrally within the filter 14. The flavour bead 20 has a diameter of around 4 mm. The flavour delivery material in the bead 20 incorporates a flavour composition comprising a menthol flavourant, which is released upon compression of the material with a force of between about 5 Newtons and about 10 Newtons. After compression, the menthol flavourant is available for release into the mainstream smoke as the smoke passes through the filter during smoking.

(5) The amount of flavour composition released from the flavour delivery material depends upon the applied compressive force such that the flavour intensity can be controlled through control of the pressure applied to the filter. The flavour bead can be compressed one or more times prior to or during smoking in order to provide a burst of menthol flavour to the smoke.

(6) An example of a suitable formulation for the flavour delivery material forming the bead and a process for forming the flavour delivery material is set out below.

EXAMPLE 1

(7) The flavour delivery material comprises a cross-linked alginate matrix with a plurality of domains of a menthol flavour composition dispersed through the matrix. To produce the flavour delivery material, the menthol flavour composition is first formed from a mixture of the following components:

(8) TABLE-US-00001 Amount Component (weight percent) Natural L-menthol 26.07 MCT Oil (MYGLIOL 810) 72.05 Other flavour 1.88

(9) The mixing is conducted with magnetic agitation at a temperature of 30 degrees Celsius for a period of 20 minutes.

(10) A matrix solution is then formed from a mixture of the following components:

(11) TABLE-US-00002 Amount Component Function (weight percent) Sodium alginate Anionic 2.36 (available from Sigma Aldrich) polysaccharide OSA-modified corn starch Amphiphilic 0.67 polysaccharide filler Glycerol Plasticiser 0.34 Sorbitol Plasticiser 0.34 Water Solvent 96.29

(12) As the amphiphilic polysaccharide filler, OSA-modified corn starch HI-CAP 100 (commercially available from National Starch & Chemical, Manchester UK) is used. HI-CAP 100 is an OSA-modified starch derived from waxy maize. Due to the hydrophobic and steric properties imparted by OSA, HI-CAP 100 is structurally significantly different from a natural starch, such as Merizet 100 starch (commercially available from Tate & Lyle), and displays, accordingly, different chemical-physical properties, including in particular interfacial and rheological properties.

(13) The mixing is conducted with a marine impeller operating at 1500 revolutions per minute and at a temperature of less than 30 degrees Celsius. The mixing is continued for 30 minutes.

(14) A solution then is formed with 30 percent w/w of the flavour composition and 70 percent w/w of the matrix solution. The solution is mixed in a shear mixer, such as a Polytron 3100B, available from Kinematica. The solution is subjected to high shear at an RPM of 15000 to 20000 whilst maintaining the mixture at a temperature of 52-55 degrees Celsius. The mixing is continued for 3 to 4 minutes to produce an emulsion of the flavour composition in the matrix polymer solution in which the size of the flavour composition droplets is reduced to below about 10 to 50 microns.

(15) The emulsion is then added to a cross-linking solution of the following composition to form the polymer matrix having the plurality of domains.

(16) TABLE-US-00003 Amount (weight Component percent) Calcium chloride 5.0 (available from Sigma Aldrich) Water 95.0

(17) The emulsion is dripped into a bath of the cross-linking solution to form a flavour delivery material in the form of beads. The emulsion is added drop-by-drop through a nozzle using a peristaltic pump. The emulsion is dropped through a 5 millimetre nozzle at a flow rate of 500 grams per hour. The process is carried out at room temperature and the bath of cross-linking solution is agitated using a magnetic mixer at a speed of 100 revolutions per minute. The emulsion and the cross-linking solution are allowed to react for a period of ten minutes.

(18) The beads are then removed from the cross-linking solution and washed in deionised water before being dried in a stream of dried air at a temperature of about 25 degrees Celsius for at least 360 minutes.

(19) The number average weight of each dry bead of flavour material is 29.1 milligrams and the number average diameter of each bead is 3.94 millimetres. The average water content of each bead is between about 4 percent and about 6 percent by weight and the average menthol content of each bead is approximately 20 to 25 percent by weight.

(20) The gradient in the concentration of calcium cations in the closed matrix structure of one of the beads produced according to the method above was measured using the following method:

(21) A bead was first embedded in Tissue Tek resin and frozen to a temperature of minus 10 degrees Celsius. A core of the bead having a cross section of 1 mm was taken along a diameter with a Harris uni-core disposable unit. The extracted core from the bead was embedded in Tissue Tek and frozen again before being transferred on the cold stage of a customised Reichert-Yung Autocut 1150 microtome in which the core was cut perpendicularly at spaced apart intervals of 125 microns to form a plurality of sections. Each section is then transferred within a frozen cylinder of Tissue Tek to a mass spectrometer for analysis of the concentration of calcium ions within the section.

(22) The highest measured calcium concentration in the sections taken from the outer 250 microns of the core was approximately 1.6 times the highest measured concentration in the sections taken from the portion of the core extending 500 microns from the centre of mass of the bead.

(23) Upon the application of a compressive force to one of the beads, the bead was found to initially crackle as the polymer matrix in the outer region was broken down before beginning to release the flavour composition from within the polymer matrix. An audible indication of the release of the flavour composition was therefore detected. Following the breakdown of the polymer matrix in the outer region the bead was found to provide a sustained release of the flavour composition over a range of force of at least 5 Newtons.