GB2469850A

GB2469850A - Volatilization device

Info

Publication number: GB2469850A
Application number: GB0907417A
Authority: GB
Inventors: James Murphy; Karl Kaljura; Robert Whiffen; Eric Wong
Original assignee: British American Tobacco Co Ltd
Current assignee: British American Tobacco Investments Ltd
Priority date: 2009-04-30
Filing date: 2009-04-30
Publication date: 2010-11-03
Also published as: GB0907417D0

Abstract

A device for delivering volatilized material to a user, comprises a heat sink (114) configured to receive heat from an external heat source. The device further comprises a volatilization component (120) including a source of volatilizable material (122). The source of volatilizable material (122) is in detachable heat transfer communication with the heat sink (114). The source of volatilizable material comprises a matrix such as polyester or cellulose acetate having suspended thereon a humectant such as propylene glycol, glycerol, triacetin, a polyol e.g. xylitol or a polymeric polyol e.g. polydextrose and an active agent such as nicotine.

Description

Volatilization Device The present invention relates to a volatilization device. A volatilization device uses a heat source to heat an aerosol generating substance; the resultant volatilized aerosol is then delivered to a user where it is inhaled. The aerosol generating substance is not combusted.

Devices for delivering volatilized material to users have several uses, in particular as smoking simulation devices. A smoking simulation device may provide a tobacco smoke taste, without the combustion of tobacco. WO 2008/015441 teaches heating tobacco in order to deliver a volatilized material to a user in the form of a simulated cigarette. A heat sink provides heat to a volatilization component, containing tobacco, through a heat pipe. For some users it may be advantageous to provide a smoking simulation device which does not contain tobacco.

The present invention provides in a first aspect, a device for delivering volatilized material to a user, comprising: a heat sink configured to receive heat from an external heat source, a volatilization component including a source of volatilizable material, wherein the source of volatilizable material is in detachable heat transfer communication with the heat sink; wherein the source of volatilizable material comprises a matrix having suspended thereon a humectant and an active agent.

Thus, the device can act as a smoking simulation device without containing tobacco.

The present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a first embodiment of a device known from the

prior art;

Figure 2 is a longitudinal cross-sectional view of the first embodiment of the prior art device of Figure 1 in an assembled condition; Figure 3 is a longitudinal cross-sectional view of the first embodiment of the prior art device of Figures 1 and 2 in a disassembled condition; Figure 4 is a longitudinal cross-sectional view of a second embodiment of a prior art device of Figure 1 in an assembled condition; Figure 5 is a schematic perspective view of a device according to the present invention in a disassembled condition; Figure 6 is a schematic perspective view of the device of Figure 5 in accordance with the present invention in an assembled condition.

With reference to Figures 1, 2 and 3 there is shown a first embodiment of a prior art device 10 known from WO 2008/015441 for delivering volatilized material to a user in the form of a simulated cigarette, which includes a reusable heat delivery component 11, and a volatilization component 20 which is usable only once and is intended to be disposed of after use. The volatilization component 20 preferably contains tobacco.

The heat delivery component 11 includes a cylindrical housing 12 which is a non-heat conducting tube. The housing 12 has a flared end 34 arranged to detachably receive the volatilization component 20. A heat transfer device, in the form of a heat pipe 16, is disposed within the housing 12, and is surrounded by a supporting and insulating material 26, for example ceramic mat or ceramic fibres. The heat pipe 16 extends longitudinally into a heat sink 14 at an end distal from the user's mouth, and at an opposed end 32 proximal to the user's mouth extends into the volatilization component 20. A plurality of perforations 18 are formed in the housing 12, which allow airflow into the supporting and insulating material 26.

The heat sink 14 collects and retains heat that is supplied from an outside source.

Heat sink 14 is preferably a metal or ceramic material, such as a honeycomb ceramic, aluminium, or may utilise an encapsulated or closed cell structure containing a phase change material. A suitable phase change material is a eutectic of tin (91 wt%) and zinc (9 wt%). Preferably, the heat sink 14 is between 15mm to 30mm in length and is approximately the circumference of a standard cigarette, which is around 25mm. The heat sink 14 is of a material which can be heated to between around 90°C to about 315°C, and may be jacketed by a thin insulating material. A thermo-chromatic indicator 40 may provide an indication to the user when the heat sink 14 is sufficiently heated to the functional heat range for use.

The heat pipe 16 is preferably a hollow metal tube, for example a titanium, aluminium or copper tube sealed at both ends and filled with a heat transfer material 36. The heat pipe 16 is arranged to transfer heat from the heat sink 14 to a volatilization section 22 of the volatilization component 20. Preferably, the heat transfer material 36 comprises a capillary wicking material that is saturated with liquid such as, for example, water. The heat pipe 16 is preferably around 2mm to 6mm in diameter and around 5cm to 9cm in length. The volatilization section 22 comprises a source of volatilizable material, which is tobacco and/or flavouring.

The volatilization section 22 is shown as having a recess 28 having an inside diameter approximately the same as the outside diameter of the end 32 of the heat pipe 16. The volatilization section 22 is complimentary in shape and adapted to receive the heat pipe end 32.

Alternatively, the volatilization section may not have a recess 28, and comprise a solid cylinder of volatilizable material. Only the heat pipe end 32 contacts the volatilizable material. The heat pipe end 32 may be shaped to penetrate into the tobacco in the volatilization section 22, to improve contact and heat conduction, and the channel section (recess) 28 may not be required. The heat pipe end 32 may take the form of a screw, a single penetration needle, a cone with flat fins or a plurality of penetration needles.

The volatilization component 20 further comprises a filter section 24 axially aligned with the volatilization section 22. The filter section defines a mouthpiece end. The filter section 24 preferably comprises a cross-linked polypropylene web, or a high denier per filament cellulose acetate, or a shaped cellulose acetate tube. The filter section 24 is attached to the volatilization section 22 by an outer paper wrap 38.

In use, the volatilization component 20 is inserted into the flared end 34 of the heat delivery component 11, with the heat pipe 16 being received in volatilization section 22 in contact with the source of volatilizable material (e.g. tobacco and/or flavouring). The heat sink 14 is heated from an outside heat source, for example a cigarette lighter, to an optimum temperature which may be indicated by a colour change of the thermo-chromatic indicator 40. When the heat sink 14 reaches a desited temperature, the user ceases heating, and draws on the filter section 24 end of the volatilization components 20. Air passes through the supporting and insulating material 26 of the heat delivery component 11 through air holes 18, and is heated by the heat transfer pipe 16. The heated air then passes through the tobacco and/or flavouring of the volatilization section 22, which has also been heated by contact with the heat pipes 16. The hot air volatilizes the tobacco or flavouring, which is then drawn into the mouth of the user.

A second embodiment of the prior art is shown in Figure 4. Reference numbers generally refer to the same parts as described as for Figures 1 to 3. The heat sink 14 is formed as a spigot l4a, and a layer of insulating material 36 is positioned between the housing 12 and the spigot 14a. The heat sink 14 projects from the housing 12 and is shaped to provide on its external surface a heat transfer region 14b which preferably carries a series of concentric ribs 37. The ribs increase the area of the heat sink 14.

The end of the housing 12 receiving the volatilization component 20 defines a socket 38, which is shaped to receive a spigot 39 of complementary shape formed on the volatilization component 20. The volatilization component 20 comprises a filter section 24 and a volatilization section 22 contained within a cylindrical housing 40. The housing 40 extends the whole length of the volatilization component 20, wherein part of its external surface has the same external diameter as the housing 12 of the heat delivery component 11, and part forms the reduced diameter spigot 39. The housing 40 has perforations l8,18a allowing airflow through part of the volatilization section 22. Additional details of a volatilization device are described in WO 2008/015441.

Figure 5 shows a disassembled volatilization device 100 according to the present invention. The volatilization device 100 is formed and operates substantially as described with reference to Figures 1 to 4, with differences as will be described. All features mentioned above and described in WO 2008/015441 are therefore part of the device 100 of the present invention unless otherwise described. Analogous to Figures 1 to 4, the volatilization device 100 has a heat delivery component 111 attachable to and detachable from a volatilisation component 120. A housing 112 has a heat sink 114 and an end 134 defining a socket to receive the volatilisation section 120, substantially as described in relation to figures 1 to 4. The end 134 may be formed by a ceramic or plastic collar. The housing 112 is preferably a cylinder with a constant diameter along its length. The housing 112 has air holes analogous to air-holes 18 as described in relation to figures 1 to 4. A heat pipe 116, as described in relation to figures 1 to 4, extends axially through the housing 112 from the heat sink 114 to the socket at end 134. The heat pipe has an end 116 preferably shaped to penetrate into the tobacco in the volatilization section 122 to improve contact and heat conduction.

The volatilization component 120 has a volatilization section 122 containing a matrix. The matrix contains volatilizable materials, which can be volatilized by heating, in particular by the heat pipe 116. The volatilizable materials include a humectant and an active agent. The volatilizable materials may optionally also include a flavouring material.

The matrix is preferably a polymer matrix, for example, formed from polyester or cellulose acetate. The humectant is preferably propylene glycol. Alternatively, the humectant may be glycerol or a triacetin. Further, the humectant may be a polyol (e.g. xylitol) or a polymeric polyol (e.g. polydextrose). The active agent is preferably nicotine. The flavouring is any known flavouring with suitable volatilization properties. The volatilization component 120 does not contain tobacco.

The polymer matrix is preferably saturated by a solution of propylene glycol and nicotine, The volatilization component 120 may contain around 18mg of nicotine.

The propylene glycol and nicotine are used as aerosol forming materials, suspended on the matrix. The humectant assists in the formation of the aerosol. The humectant has the ability to form agglomerates with water molecules, in order to provide a "mouth filling" effect similar to smoking a conventional cigarette. The humectant and active agent are more freely available for volatilisation than if they were suspended on tobacco, which is more porous.

Figure 6 shows the volatilization component 120 connected to the heat delivery component 111. The heat pipe 116 enters a recess in the matrix forming the volatilization section 122. Alternatively, the matrix may not have a recess and an end of the heat pipe 116 only may contact the matrix.

The proportion of humectant and active agent on the matrix is selected so that the aerosol "smoke" inhaled by a user is optimised. The smoke contains nicotine free dry particulate matter (NFDPM), also known as "tar", of which the majority in the present invention is the humectant. It is advantageous to provide at least a minimum quantity of active agent for each quantity of NFDPM. The NFDPM: active agent ratio is preferably equal to or more than 10:1, ie there is one or less units (by mass) of active agent (in particular, nicotine) for every 10 units (by mass) of NFDPM. The NFDPM:active agent ratio is preferably between 10:1 and 50:1, and is more preferably approximately 20:1.

The proportions of humectant and active agent (nicotine) initially suspended on the matrix are preferably pre-determined in order to obtain a required ratio in the smoke. In particular, for one gram of humectant (e.g. propylene glycol there is greater than 16mg active agent (nicotine). Preferably for each one gram of humectant (in particular propylene glycol) there is at least 20mg active agent (in particular nicotine), or at least 25mg active agent or at least 30mg active agent.

Alternately or in addition, the solution of humectant and active agent on the matrix further comprises water. The water acts to reduce the NFDPM: active agent ratio.

Alternatively, or in addition, the contact area between the heat pipe and the matrix may be reduced in order to obtain the required smoke characteristics. In particular, the matrix of the volatilization component 120 may not have a recess for receiving the heat pipe. The heat pipe may only contact the matrix at its end surface, in order to reduce the quantity of NFDPM yielded during use.

The matrix forming the volatilization section 122 preferably extends throughout the whole length of the of the volatilization component 120. The volatilization component 120 does not include a filter.

In a further embodiment, the volatilization component 120 comprises a hollow tube through which volatilized material passes. The hollow tube is at an end proximal to the user's mouth and axially aligned with the volatilization section 122. The hollow tube has an outer diameter which is the same as the volatilization section 122. The hollow tube functions as a condensation zone for the aerosol, assisting the cooling of the vapour formed by heating. The vapour condenses into droplets within the airstream as it is drawn towards the user's mouth, further droplets being formed by a step change in temperature to create the aerosol.

The solution containing propylene glycol and nicotine is aerosolised at around 50 to °C. The relatively low temperature required to aerosolise the solution allows a relatively small heat sink 114. The circumference of the heat sink 114 may be approximately 24.7mm, matching a standard king-size cigarette.

The heat sink 114, which preferably includes a phase change material (PCM), can also be relatively small and light. The heat sink is configured to receive heat from an external heat source. The external heat source is physically separate from the device and can supply heat to the heat sink 114. The volatilization device 100 does not generate any heat itself. The external heat source may be a conventional cigar or cigarette lighter, or may be any external heat source capable of heating the heat sink to its operating temperature.

The volatilization component 120 is sealed with a removable foil wrapper. The wrapper may surround the entire component, or cover only the ends where the matrix is exposed. The wrapper is preferably removed prior to use. The foil wrapper provides protection against tampering and ensures the volatilizable materials cannot be accessed accidentally by a child.

The volatilization component 120 has a stepped diameter. The second, smaller diameter, portion forms a spigot and is insertable into the socket of the delivery component 111. The larger diameter portion is not insertable into the socket, and abuts against the end 134 of the housing 112 when the volatilization component 120 is fully inserted. The exterior surface of the larger diameter portion has the same diameter as the exterior surface of the housing 112 at end 134. The exterior surfaces of the housing 112 of the heat delivery component 111 and volatilization component 120 are therefore substantially flush where they meet. The device 100 simulates the look of a conventional cigarette since the assembled device has a smooth, preferably constant, diameter across the join between the two attachable sections.

In use, the volatilization component 120 is inserted into the end 134 of the heat delivery component 111, with the heat pipe 116 being received in contact with the source of volatilizable material, i.e. the matrix on which the humectant and active agent are suspended. The heat sink 114 is heated from an outside heat source, for example a cigar or cigarette lighter, to an optimum temperature. When the heat sink 114 reaches a desired temperature, the user ceases heating, and draws on the mouth end of the volatilization component 120. Air passes through the air holes in the housing 112, and is heated by the heat transfer pipe 116. The heated air then passes through the matrix, which has also been heated by contact with the heat pipes 16.

The hot air volatilizes the solution in the matrix, and the aerosolised nicotine, propylene glycol, and optionally flavouring, are drawn into the mouth of the user.

Once the volatilizable material has substantially all been aerosolised, the volatilization component 120 is disposed of and replaced by a fresh volatilization component.

Any of the features described in any of the embodiments or in the described prior art embodiments may also be applied to any other of the embodiments of the present invention.

Claims

-10 -Claims 1. A device for delivering volatilized material to a user, comprising: a heat sink configured to receive heat from an external heat source, a volatilization component including a source of volatilizable material, wherein the source of volatilizable material is in detachable heat transfer communication with the heat sink; wherein the source of volatilizable material comprises a matrix having suspended thereon a humectant and an active agent.
2. A device as claimed in claim 1 wherein the humectant is propylene glycol.
3. A device as claimed in claim 1 or 2 wherein the active agent is nicotine.
4. A device as claimed in any one of the preceding claims wherein the matrix is a polymer based matrix.
5. A device as claimed in claim 4 wherein the matrix is formed of polymer based polyester or cellulose acetate.
6. A device as claimed in any one of the preceding claims wherein a flavouring is additionally suspended on the matrix.
7. A device as claimed in any one of the preceding claims wherein the heat sink includes a phase change material.
8. A device as claimed in any one of the preceding claims further comprising an elongate heat transfer device in heat transfer relation with the heat sink, wherein the heat transfer device is in detachable heat transfer communication with the source of volatilizable material.

-11 -
9. A device as claimed in any one of the preceding claims wherein the heat sink is mounted in a housing, and a portion of the volatilization component is configured to attach to the housing.
10. A device as claimed in any one of the preceding claims wherein the volatilization component is sealed with a removable foil wrapper.
11. A device as claimed in any one of the preceding claims wherein the volatilization component comprises a hollow tube through which volatilized material passes.
12. A device is claimed in any one of the preceding claims wherein the proportions of humectant and active agent are selected such that, in use, the ratio of nicotine free dry particulate matter (NFDPM):active agent in smoke generated is equal to or more than 10:1, or the NFDPM:active agent ratio is between 10:1 and 50:1, or the NFDPM:active agent ratio is approximately 20:1.
13. A device as claimed in any one of the preceding claims wherein the proportions of humectant and active agent suspended on the matrix is such that for each one gram of humectant there is at least 16mg of active agent, and preferably at least 20mg of active agent or at least 25mg active agent.
14. A device is claimed in any one of the preceding claims further comprising water suspended on the matrix.
15. A device as claimed in claim 8 wherein an end of the heat transfer device only can contact the source of the volatilizable material.
16. A device substantially as hereinbefote described with reference to and as shown in Figures 5 or 6.