GB2496906A - Additive release component for smoking article - Google Patents

Abstract

An additive release component for use in a smoking article comprises a substrate 17, 20, an additive 18, 21 supported by the substrate and a barrier material 19, 22. The barrier material overlies the additive and is configured to release the additive from the substrate 17, 20 in response to a change in environmental parameter such as the presence or an increase in, moisture, an increase in heat or a change in pH. The substrate may be mesoporous silicon or macroporous silicon having a surface area of 10 to 500 sq.m./g., a porosity of 35 to 99%, a pore volume of at least 0.5cc/g and/or a BET surface area of at least 1000 sq .m/g.

Description

Additive release component This patent specification relates to additive release components suitable for use in smoking articles.

It is known to provide additive release components containing additives such as fiavourants inside smoking articles. The additive may he released through rupture of the additive release component. Thus, by applying force to the outside of the smoking article, the smoker may break the additive release component and release the flavourant. A smoker wishing to add flavour to the smoke may consequently do so by simply squeezing the smoking article.

This specification discloses a number of features which alone or in combination form concepts that are the subject of this disclosure.

According to a first concept, an additive release component for use in a smoking article is provided. The additive release component comprises a substrate, an additive supported by the substrate and a barrier material. The barrier material overlies the additive and is configured to release the additive from the substrate in response to a change in an environmental parameter.

According to a second concept, a filter for a smoking article is provided comprising an additive release component according to the first concept.

2 According to a third concept, a smoking article is provided comprising an additive release component according to the first concept or a filter according to the second concept.

Tn order that these and other concepts of the disclosure may be better understood, embodiments thereof will he described, by way of example only, with reference to the accompanying drawings (not to scale), in which: Figure 1 shows a filter comprising an additive release component according to a first embodiment.

Figure 2 shows a filter comprising an additive release component according to a second embodiment.

Figure 3 shows a filter comprising an additive release component according to a third embodiment.

Figure 4 shows a filter comprising an additive release component according to a fourth embodiment.

Figure 5 shows a filter comprising an additive release component according to a fifth embodiment.

Figure 6 is an exemplary schematic representation of a porous material carrying additive material and additionally coated with an encapsulating material in accordance with an embodiment as herein described.

Figure 7 is an exemplary schematic representation of an additive release component according to another embodiment as herein described, in which an additive is supported on a substrate and a barrier material overlies the additive.

As used herein, the term "smoking article" includes smolceable products such as 2 cigarettes, cigars and cigarillos whether based on tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes and also heat-not-burn products (i.e. products in which flavour is generated from a smoking material by the application of heat without causing combustion of the material).

Typically, smoking articles are provided with filters for removing constituents from the smoke.

For purposes of illustration, and not limitation, Figure 1 shows an exemplary smoking article 1 comprising a cylindrical rod of smokeable material 2, in this case tobacco, and a filter 3. The filter 3 comprises a substantially cylindrical plug of filter material, which is wrapped in a plugwrap (not shown).

The rod of srnokeable material 2 is aligned with the filter 3 such that the end of the tobacco rod 2 abuts the end of the filter 3. The rod is wrapped in a paper wrapper (not shown), and is joined to the filter 3 by tipping paper 4 in a conventional manner. f0

As illustrated, the smoking article 1 comprises an additive release component 5, which is a system containing an additive and from which the additive may he released under specific circumstances. The additive release component may suitably he supplied to the consumer as part of a smoking article. The additive release component may be located in any position in the smoking article. Tn this embodiment, the additive release component 5 is positioned in the filter 3.

As illustrated, the additive release component 5 is visible at the huccal end of the filter 3. Tn tins way the user maybe made aware of the presence of the additive release component S in the filter 3. Tn other embodiments, the additive release component S is not visible to the user.

Tf permitted by local regulations, the additive release component 5 may he coloured to allow it to be easily distinguished from the remainder of the filter 2 material and its presence to he quickly identifiable by the consumer. Such colouring may also serve to make any discolouration of the additive release component S less obvious. The additive release component S is said to be coloured when it is given a colour that is different to the natural colour of the additive release component 5 comprising an additive. For example, the additive release component S may be green, pink, red, orange, brown, yellow, grey, cyan, blue, violet, or any other colour.

The colouring may also serve to provide the user with an indication of the type of additive present in the filter. For example, different colours may be used for different additives.

Colourants for use in the described additive release components may he subject to applicable regulatory approval for use in smoking articles. The colouring may he a food grade dye, for example, or a colourant, such as cocoa, liquorice, caramel or malt, or an extract. The presence of an inorganic material, such as iron oxide, may also give a darker colour to the additive release component 5.

Finely ground, granulated or homogenised tobacco may also be used. Industry approved food colourants may be used, such as LISDa (caramel), LiSt (brilliant black BN), Fi53 (vegetable carbon) or R155 (brown FIT).

The additive release component 5 may take any suitable shape and form. It may be shaped to locate at a specific site in the smoking article or filter. The additive release component 5 may he engaged in a cavity, recess or other shaped region in the filter 3. This region and the additive release component 3 may he of complementary shapes. In this embodiment, the additive release component 5 is substantially cylindrical in shape and is engaged in a substantially cylindrical groove in the filter 3.

In this embodiment, the additive release component S extends substantially longitudinally within the filter material in a direction substantially parallel to a longitudinal axis of the filter 3. The length of the additive release component 5 2 may he limited in practice by the length of the filter 3 and it will, therefore, usually have a length of at least about 4 mm or 5 mm, and a maximum length of about 27 mm. Typically the additive release component 5 is about 6-25 mm, 7- 23 mm or 8-21 mm in length, normally 8-12 mm in length, such as about 10 mm in length.

A typical cigarette diameter is about 8 mm and, therefore, the additive release component s will have a diameter smaller than this. Additive release components for use in other smoking articles may have different circumferences accordingly.

By way of further illustration, Figure 2 shows a smoking article 6 according to a second embodiment.

In this embodiment, for the purposes of illustration, the smoking article 6 resembles that of the first embodiment, as described above, except that the additive release component 7 comprises three strips 7a, 7b and 7c. The strips 7a, to 7b and 7c are arranged radially with respect to each other about a common longitudinal axis. The strips meet in the centre of the additive release component 7, such that the strips within the additive release component have a Y-shaped cross-section. In embodiments where the additive release component comprises multiple strips, any numbet of strips may he employed. Thus, in other embodiments, the additive release component 7 comprises two strips or more than three strips, such as four, five, six, seven or eight strips, arranged radially with respect to each other. In some embodiments, the strips may not meet in the centre of the additive release component.

Each strip 7a, 7h and 7c may he of any suitable width, such as about 2-5 mm in width, preferably about 3 mm in width.

Each strip 7a, 7b and ft may comprise the same additive or different additives.

For example, a first strip may comprise a flavourant (such as menthol) and a 2 second or further strip may comprise a deodoriser, a diluent, an adsorbent or another substance that is capable of modifying smoke. Different Ilavourants could he provided in different strips. Any and all combinations of additives as described herein are envisaged.

The additives contained in tile different strips 7a, 7h and 7c may have the same mode of activation or differing modes of activation. For example, a first strip could release its contents in response to moisture, a second strip could he responsive to an increase in heat or a change in pIT, while a third strip could be responsive to sonic other property of the smoke being drawn through the filter or to mechanical manipulation At least one of the strips 7a, 7h and 7c will nevertheless be configured to provide release of additive in response to a change in an environmental parameter. Preferably, more than one of the strips 7a, 7h and 7c will be so configured. Most preferably, all of the strips 7a, 7h and 7c will be so configured. The change in an environmental parameter may be an increase in heat, a change in p1-I or it may he the presence of moisture or an increase in moisture. Tn a preferred embodiment, one or more of the strips 7a, 7h and 7c are contigured to provide release of additive in response to moisture.

Figure 3 shows a smoking article 9 according to a third embodiment.

Tn this embodiment, the smoking article 9 has a construction similar to that of the first and second embodiments, as described above, except that the additive release component 10 is cone-shaped. In other embodiments, the additive release component may, for example, he spherical, hemispherical, trapezoidal, ovoid, pyramidal, oblate, ellipsoidal, cubic or any other suitable shape.

The additive release component 10, in this embodiment, extends only partway along the length of the filter it. It may consequently have a minimum length of about 4 mm or 5 mm and a maximum length of about 15 mm, typically about 4- 12 mm and usually about 4-8 mm in length, for example, about 6 mm in length.

In other embodiments, the additive release component 10 may extend along the 2 entire length of the filter 11.

Alternative arrangements, offering variety or controllability in additive delivery, are also provided.

Figure 4 illustrates one such embodiment. Tt shows a smoking article 12, having a construction sinular to that of the first embodiment, as described above, except that the additive release component 13 comprises three sections 13a, 13h and l3c. In embodiments where the additive release component comprises multiple sections, any number of sections may be employed. Thus, in other embodiments, the additive release component 13 may comprise more than three sections, such as four, five, six, seven or eight sections, or it may comprise just two sections. The sections Ha, 1 3h and 13c are aligned such that the end of a first section 1 3a abuts the end of the next section 1 3b, and so on. Thus, the additive release component 13 extends substantially longitudinally within the filter material in a direction substantially parallel to a longitudinal axis of the filter 14. f0

The length of each section will he limited in practice by the length of the smoking article filter and the number of sections. Tn the embodiment shown, each of sections 13a, 13h and l3c may, therefore, have a length of about 4 mm or 5 mm to about 9 mm, such as about 7 ntm or 8 mm in length.

Each section l3a, l3b and l3c may comprise the same additive or different additives, as described above for the strips 7a, 7h and 7c in the second entbodiment.

The additives contained in the different sections 13a, 13h and 13c may have the same mode of activation or they may have differing modes of activation, also as described above for the strips 7a, 71 and 7c in the second embodiment.

Figure 5 shows a smoking article 15 according to a fifth embodiment. In this 2 embodiment, the sntoking article 15 resembles that of the first embodiment, as described ahove, except that the smoking article 15 contains two additive release components 16a and 16h. In other embodiments, the smoking article 15 comprises three, four, five or more additive release components.

The additive release components 16a and 16h are aligned side-by-side in the filter 17. In other embodiments, multiple additive release components may he positioned, for example, at regularly spaced intervals along the length of the smoking article. They may he arranged in a substantially parallel arrangement.

Alternatively, multiple additive release components may he positioned in a cluster, a radially symmetrical pattern or a more complex arrangement. The additive release components may he attached together or may he independent of one another within the smoking article.

The multiple additive release components 16a and ILli are generally located substantially centrally within the filter. However, they need not he located at or around the diametric centre of the filter, and may he off-centre, and may even he situated substantially towards the circumferential edge of the filter, such as towards or adjacent to a periphery of the filter.

The additive release components may have the same or different shapes, and may he of the same or of different sizes. The size of each additive release component will depend upon the type of smoking article, the number of additive release components in the filter and/or the arrangement of the additive release components in the filter. In this embodiment, each additive release component 1 La and 1 Lb will have a diameter of less than 4 mm (the diameter of a typical cigarette being about 8 mm).

Each additive release component may comprise the same additive or different additives, as described above for the strips 7a, 7b and 7c in the second embodiment.

2 The additives contained in the different additive release components may have the same mode of activation or they may have differing modes of activation, also as described above for the strips 7a, 7b and 7c in the second embodiment.

Tn the majority of the embodiments described thus far, the additive release component extends over the full longitudinal length of the filter. However, in other embodiments, the additive release component may he provided in a single filter element, for use in combination with one or more other filter elements as part of a composite filter comprising a plurality of abutted filter sections, such as a dual or triple filter.

The composite filter may comprise a single filter element comprising an additive release component as described herein. Tins element may he located at the buccal end of the filter, tobacco rod end of the filter or as a central filter element. Alternatively, the composite filter may comprise a plurality of filter elements comprising additive release components. For example, the filter may be a triple filter comprising the additive release components in the filter elements towards the mouth and tobacco rod ends of the filter. When the filter element is part of a composite filter, the filter elements of the composite filter not comprising an additive release component may comprise one or a combination of cellulose acetate, polypropylene, paper or any other suitable material, and may alternatively or additionally comprise adsorbent material, for example, activated carbon, a resin material such as amberlite or duolite, and/ or catalytic material.

Preferably, however, any filter elements comprising adsorbent material are positioned within the composite filter nearer to the tobacco rod end of the filter than any elements comprising additive release components.

In the embodiments described thus far, the additive release component is aligned with a longitudinal axis of the filter. While this may be preferable, it is not essential. Thus, in alternative embodiments, the additive release component may he aligned with any other axis of the filter.

In all of the embodiments described herein, the additive release component comprises a substrate. The substrate may be any material capable of supporting the additive that is suitable for use in a smoking article, such as, for example, a carbon material, a resin, a web material, a laminar sheet material, a woven fabric, a ribbon, a yarn, a thread, a fibrous material, a polymeric material or a film. It can he a synthetic material or a natural material. It may he porous or non-porous. In an embodiment, it is not tobacco or tobacco-containing material. -10-

Preferably the substrate comprises or consists of a porous material. The porous material may be a sponge-like material, an adsorbent material, a gel material or any other suitable material. In some embodiments, the porous material is not an adsorbent. As illustrated in Figure 6, the porous material 17 preferably has a surface morphology with a plurality of indentations in which a substantial quantity of additive 18 can reside.

When the additive release component comprises a sponge-like porous material, /0 any suitable sponge-like material may be used. The sponge-like material may be a foamed material, which may he a foamed plastic polymer such as polyvinyl alcohol (PVOH) or cellulose acetate. The sponge-like material may he formed from a naturally occurring element, such as silicon.

Suitable adsorbent materials include carbon, activated carbon, activated charcoal, zeolite, silica gel, sepiolite, clay, aluminium oxide, carbonaceous resin or combinations thereof.

Any suitable gel material may he used.

Preferably the porous material is in particulate form. In an embodiment, the particles of porous material have an average particle size in the range of about 0.05-200 Jim, preferably about 0.5-50 Jim, 1-45 Jim, 1.5-30 Jim, 1.8-20 Jim or 2-Jim.

The porous material may comprise micropores, ntesopores and/or macropores.

In accordance with nomenclature used by those skilled in the art, pores in a porous material that are less than 2 nm in diameter are called "micropores" and pores having diameters of between 2 nm and 50 nm are called "mesopores".

Pores are referred to as "macropores" if their diameter exceeds 50 nm.

-11 -Preferably, the porous material is a mesoporous material, typically having pores of about 5-20 nnt in diameter, or a macroporous material, typically having pores of about 50-1000 nm in diameter. The pores of the macroporous material may he 50-500 nm, 250-750 nm or 500-1000 nm in diameter, for example, they may he 150-350, 100-300, 400-600 or 750-900 nm in diameter. Pores having diameters greater than 500 nm do not usually contribute significantly to the adsorhency of porous materials. Thus, macroporous materials having larger pore volumes may release additive from within the pores more readily.

to Preferably, the porous material is highly porous. A suitable porosity is about 35- 99% porosity, preferably about 50-80% porosity and most preferably about 65- 75% porosity. Suitable techniques for measuring porosity will be known to the skilled person. In an embodiment, the pore volume of the porous material is at least about 0.5 cc/g, preferably at least about 0.6, 0.7 or 0.8 cc/g.

Preferably, the porous material has a high surface area. Suitably the surface area will be about 10-500 m2/g, preferably about 100-500 or 200-400 m2/g, such as about 250 m2/g. A suitably porous material has a BET specific surface area of at least about 1000 m2/g, preferably at least about 1300, 1400, 1500, 1600, 1700 or 1800 m2/g. In general, the greater the BET specific surface area, the greater the amount of additive that can be carried by the porous material. however, the brittleness can increase if the surface area is too high. Preferably, the BET specific surface area is about 3000 m2/g or less, more preferably h()ut 2500 m2/g or less and most preferably about 2000 m2/g or less.

Silicon is a suitable porous material, as it may he provided with an extensive network of pores, forming a vast surface area. Preferably, mesoporous or macroporous silicon is used. Mesoporous silicon has of 2-50 nut in diameter, typically of about 5-20 nm in diameter. Macroporous silicon suitably has pores of about 250-750 nm in diameter. Porous silicon has a high surface area, typically about 10-500 m2/g, preferably about 250 m2/g. It has a typical porosity of about 35-99% porosity, preferably about 65-75% porosity. -12-

The substrate may take any physical form. For example, it may comprise or consist of granules. Alternatively it may take the form of a larger, shaped structure, such as a monolithic structure, as illustrated in Figures 1-5, for

example.

The sue of the additive release component may be dependent on the amount or volume of additive required, which in turn may be dependent on a number of factors, including the potency of the additive and the degree of smoke modification desired. Generally, it is desirable for the volume of an additive release component to he as large as possible, so that as much additive as possible may be provided. However, since additive release components are usually located within the filter, large components may have an adverse effect on the filtration or draw characteristics of the filter. The use of a porous material as described herein is thus advantageous, as it permits a high surface area to volume ratio to be achieved. Accordingly, a high volume of additive can he provided in the pores, while keeping the volume of the additive release component to a minimum.

The additive release component further comprises an additive. The additive may be anything which may be added to smoke, the atmosphere in the vicinity of a smoking article or the fingers or lips of a smoker. An additive may modify the properties of smoke or alter the smoking experience, for example by adjusting the flavour or odour of tile smoke or smoking article. The additive may be a 2 deodoriser, a diluent, an adsorbent or any other substance that is capable of modifying the smoke. The additive may he water. Where local regulations permit, the additive preferably comprises or consists of a flavourant, such as menthol.

As used herein, the term "flavour", "tiavouring" and "flavourant" refer to materials which, where local regulations permit, may he used to create a desired taste or aroma in a product. They may include extracts (e.g., licorice, hydrangea, 1-, -13 -Japanese white bark magnolia leaf, chamomile, fenugreek, clove, menthol, Japanese mint, aniseed, cinnamon, herb, wintergreen, cherry, berry, peach, apple, 1)ramhuie, bourbon, scotch, whiskey, spearmint, peppermint, lavender, cardamon, celery, cascarilla, nutmeg, sandalwood, bergamot, geranium, honey essence, rose oil, vanilla, lemon oi, orange oil, cassia, caraway, cognac, jasmine, ylang-ylang, sage, fenneL piment, ginger, anise, coriander, coffee, or a mint oil from any species of the genus Mentha), flavour masking agents, bitterness receptor site blockers, receptor site enhancers, sweeteners (e.g., sucralose, acesulfan]e potassium, aspartame, saccharine, cyclamates, lactose, sucrose, glucose, fructose, sorhitol, or mannitol), and other additives such as charcoal, chlorophyll, minerals, hotanicals, or breath freshening agents. They may he imitation, synthetic or natural ingredients or blends thereof.

The flavour may he a tobacco flavour. Where the flavour is delivered in liquid form, the tobacco flavour could be derived from tobacco extract. Where the additive is in solid form, the additive may be tobacco leaf or reconstituted tobacco material in shredded, particulate or granular form.

The additive may he in any suitable form, for example, a solid (such as a powder, granules, particles, capsules or microcapsules), a liquid (such as an oil, liquid flavourant, deodoriser, water etc.) or a gas (such as an aromatic composition).

The additive may he an adsorbent and/or may he in granular, powdered, particulate or any other suitable form. In this case, the additive (e.g. adsorbent 2 material) preferably has a mean particle size of less than 750 im, more preferably less than 500 im. Most preferably, the additive (e.g. adsorbent material) has a mean particle size of between 200 and 500 &m, such as 200-400 im or 250-350 im. The particle sue is considered to he the diameter of the particle. Naturally, smaller particle sues will he appropriate for the additive when the substrate is a micro-or meso-porous material and the additive is to be carried in the pores.

Suitable adsorhents include those mentioned above for the additive release component. -14-

The additive may comprise a mixture of materials. Any combination of the aforementioned flavourants, deodorisers, diluents, adsorhents or any other substance that is capable of modifying the smoke may he used.

The additive is supported by the substrate. For example, the additive may he carried on a surface of the substrate. In an embodiment, the additive may cover, or substantially cover, the entire surface of the substrate. In other embodiments, the additive may cover only a portion of the surface of the substrate, for to example, the additive may cover up to 90, 80, 75, 70, 60, 50, 40, 30 or 25?/ of the total surface area of the substrate.

If the substrate is a porous material, the additive is preferably contained in the pores of the porous material. The additive may he loaded into the pores of the porous material during production of the additive release component, and carried within the pores until its release.

The additive may be impregnated in the substrate. In an embodiment, it is not impregnated in the substrate.

Whichever arrangement is employed, the additive will typically be in intimate or direct contact with the substrate, i.e. it will typically be directly supported by the substrate, rather than supported through an intermediate entity.

2 The amount of additive held by the additive release component is dependent on a number of factors induding the potency of the additive, the degree of smoke modification required, the capacity of the additive release component to hold additive, and so on.

Suitably, the level of loading of the additive on the additive release component is at least 10, 20, 30, 40, 50, 60, 70, 80 or 90% of the total weight of the additive release component. Preferably, the level of loading of the additive is -15 -approximately 80-959/o or 85-95% by weight and, most preferably, 90-95% by total weight, of the additive release component. In general, the greater the porosity of the additive release component, the greater the loading efficiency of the additive.

If no further steps are taken, the additive may diffuse freely from the substrate in the additive release component. There may be several factors influencing the stability and migration of additives under ambient conditions. These factors may include hydrophobicity or hydrophillcity, viscosity, saturated vapour pressure at room temperature, boiling point, molecular structure (such as hydrogen bonding or Van der Waals forces), the absorptive/adsorptive interaction between additive and the substrate and the loading level of the additive. Some additives will suffer from migration problems to a greater extent than others.

If a significant proportion of the additive is lost from the substrate prior to use as herein described, it will naturally have a negative impact on the performance of the additive release component in the lit smoking article.

In order to control release of the additive, the additive release component described herein is configured to provide release of the additive in response to a change in an environmental parameter. The change in an environmental parameter may, for example, he the presence of moisture, an increase in moisture, an increase in heat or a change in p1-I. Preferably, however, the additive release component described herein is configured to provide release of 2 the additive in response to moisture, i.e. it is moisture-activated.

As used herein, "release of the additive in response to moisture" includes release of the additive upon contact with moisture and also release in response to an increase in existing moisture levels. The term "moisture" refers to any liquid or vapour, including water (vapour) or other solvent (vapour). -16-

As illustrated in Figure 6, the porous material 17 and the additive 18 are thus preferably encapsulated in a material 19 that is configured to release the additive 18 from the substrate in response to moisture. If the additive release component is formed from the porous material, the additive release component in its entirety may he so encapsulated. If the porous material is particulate, each particle may be so encapsulated. The barrier material 19 forms part of the additive release component.

Naturally, the barrier material 19 need not encapsulate the additive-carrying porous material 17, it could simply cover tile pores. In an embodiment, therefore, the harrier material 19 overhes the additive 18 in each pore, hut does not entirely surround the porous material 17. This is a less preferred embodiment, however, owing to the additional challenges that it presents in manufacture, for example.

The harrier material 19 may function as a shell, cap, outer coating, sealant overcoat or such like. Suitably, the additive 18 is contained in the pores of the porous material; the barrier material 19 thus retains the additive 18 in the pores of the porous material 17 until release of the additive is desired, i.e. the coating may capture' or trap' the additive in the pores during storage of the additive release component and prior to use. The harrier material may thus he a material that dissolves, disintegrates, ruptures or otherwise loses its structural integrity upon contact with moisture, such as, for example, polyvinyl acetate, polyvinyl alcohol (PVOH), a cellulose-based hinder (for example, methylcellulose) or a 2 polysaccharide. Preferahly the harrier material is soluble in water and/or comprises polyvinyl acetate, PVOH, methylcellulose or a polysaccharide.

The harrier material 19 thus hinders any migration of the additive 18 from the porous material 17 during storage and prior to use. This is particularly advantageous for porous materials that may hind additive materials relatively xv e a k 1 y.

-17 -In the embodiment shown in Figure 6, the porous material 17 may be meso-or macro-porous silicon and the harrier material 19 may be polyvinyl acetate, PVOH, methylcellulose or a polysaccharide. The additive 18 may he a flavourant (such as menthol).

An alternative embodiment is illustrated in Figure 7. Tn this embodiment, the substrate 20 is a non-porous material, such as a non-porous resin, polymer or sheet material. The additive 21 which may he a flavourant or such like) is supported on the substrate 20; in the embodiment shown, the additive 21 is carried on a surface of the substrate 20, hut does not cover the entire surface of the substrate 20, i.e. it may be applied to one surface only of the substrate. As herein described, in other embodiments, the additive 21 may cover, or substantially cover, the entire surface of the substrate 20.

Overlying the additive 21 is a barrier material 22, such as polyviny] acetate, PVOH, methylcellulose or a polysaccharide. The barrier material 22 covers the surface(s) of the additive i that would otherwise he exposed if the harrier material 21 was not present. In the embodiment shown, the harrier material 22 does not encapsulate the additive-carrying substrate 20. Tn fact, the additive 21 is enclosed partly by the barrier material 22 and partly by the substrate 20. Tn alternative embodiments, however, the barrier material 22 may encapsulate the additive-carrying substrate 20.

Whatever the arrangement of substrate 20, additive 21 and barrier material 22, 2 the additive 21 is held on the substrate 20 by the harrier material 22 until the latter dissolves, disintegrates, ruptures or otherwise roses its structural integrity upon contact with moisture. The harrier material 22 thus overlies the additive 21 sufficiently to keep it in place on the substrate until release of the additive is initiated. Additive release in these embodiments is believed to he predictable, reliable and effective. Additive release components that are designed to release their contents in response to moisture thus allow the smoker to enjoy the full effect of the additive contained within the filter.

-18 -Tn some embodiments described herein, the harrier material suitably does not separate the additive from the substrate. Thus, the barrier material will usually not he found between the additive and harrier material, and will not encapsulate only the additive. Rather, the barrier material serves as a cap' or such like to hold the additive in intimate contact with the substrate until the harrier material comes into contact with moisture.

The arrangements shown in Figures 6 and 7 may equally he employed with other types of barrier material 19, 22.

For example, in some embodiments, the barrier material 19, 22 maybe conf9gured to release the additive 18, 21 from the substrate 17, 20 in response to an increase in heat. In these embodiments, the barrier material 19, 22 is suitably a material that melts and/or otherwise degrades at a temperature above room temperature (typically 20-25 Cc) and/or the temperature at which smoking articles ate produced and stored. The additive 18, 21 is thus ideally retained in the additive release component by the barrier material 19, 22 prior to use of a smoking article containing the same. When the smoking article is smoked, its temperature increases. The barrier material 19, 22 \\Till thermally degrade when it reaches its melting/degradation temperature and the additive 18, 21 will thus be released from the substrate 17, 20 at that time.

The additive release component comprising such a barrier material may he placed in any location in the smoking article. For example, if the additive release component is located in the tobacco rod, a harrier material that thermally degrades at a high temperature, for example between 50 and 900 oc such as above 100, 200, 300, 400, 500, 600, 700 or 800 °C, may he used. Additive release in these embodiments may thus be in response to a substantial increase in heat, -19 -such as in the order of 50 °C or more. 100 °C or more, 250 ° or more or 500 or more.

If, alternatively, the additive release component is located in the filter of a smoking article, a harrier material that thermally degrades at a lower temperature than the foregoing may be used, for example, the harrier material may thermally degrade at a temperature between room temperature and 50 DC, such as between and 40 °C and preferably around 30 °C, such as between 28 and 35 °C.

Additive release in these embodiments may thus he in response to an increase in heat in the order of 30 O(' or less, such as 20 °C or less, 10 °( (Jr less or 5 °C (Jr less.

Any suitable thermally degradable barrier material may be used, such as, for example, pectin, wax, polyethylene glycol, polyvinyl acetate or another suitable /5 thermally degradable polymer.

In other embodiments, the barrier material 19, 22 may be configured to provide release of the additive 18, 21 in response to a change in pH. The change in p11 may be an increase in pEl or it may be a decrease in p1-i. In these embodiments, the barrier material 19, 22 is a material that degrades at, above or below a particular p11. For example, it may degrade at, above or below a ph of approximately 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14. It may degrade at an acidic p11, a neutral pH or a basic p11. It may degrade in or over a pH range, for example in the range of 0-3, 0-5, 0-7, 2-5, 3-6, 5-7, 6-8, 7-10, 7-14, 9-12 or 12-14.

If the additive 18, 21 is to he released from the substrate 17, 20 upon contact with smoke, as the latter is drawn through a lit smoking article comprising such materials, the barrier material 19, 22 is suitably a material that degrades at the pH of the smoke. The ph of the smoke depends upon the type of tobacco used in the smoking article. For example, flue cured tobacco is believed to create smoke with a p11 of approximately 5-6, US Blended tobacco (i.e. Burley tobacco -20 -blended with other kinds of tobacco, such as Virginia or Oriental tobaccos) is believed to create smoke with a p1-I of approximately 5.5-6.5, dark air cured tobacco is believed to create smoke with a pH of approximately 7-7.5 and cigar tobacco is believed to create smoke with a pH of approximately 8-8.5. The harrier material may thus he a material that degrades at a pH of between 5 and 9, for example, at a pH range of 5-6, 5.5-6.5, 7-7.5 or 8-8.5.

Alternatively, the additive 18, 21 may he released from the substrate 17, 20 located in the smoking article by a stimulus other than the smoke. Tn these embodiments, the harrier material 19, 22 may thus be a material that degrades at a pH that is different to that of the smoke. For example, it may degrade at a p11 that is not in the range of 5-9, 5-6, 5.5-6.5, 7-7.5 and/or 8-8.5, such as 0-4 or 9-14.

The additive 18, 21 is thus ideally retained in the additive release component by the barrier material 19, 22 xvhile a smoking article containing the same is produced and stored. Suitably, only when the smoking article is smoked will the harrier material 19, 22 in the additive release component degrade, once it reaches the appropriate ph. The additive 18,21 will he released from the suhstratel7, 20 at that time.

Suitable materials for use in these embodiments, if local regulations perniit, may include enzymes that become active at the chosen p1-f; for example, a cellulosic harrier material may be associated with an inactive forni of a cellulose-degrading 2 enzyme, which enzyme becomes active at the chosen pH.

The additive release component may he manufactured using any suitable method, the method of manufacture being dependent on the precise composition and make-up required. Suitable methods of manufacture may include techniques such as anodisation, stain-etching, milling or jet milling. Any materials for the additive release component must he safe to use, and are subject to regulatory approval.

-21 -The additive may be loaded onto the additive release component using an additive applicator. An apparatus for applying additive to an additive release component may comprise a holder for the additive release component and an applicator capable of applying additive to the additive release component. The applicator may comprise an applicator head for application of the additive to the additive release component and a supplier for supplying additive to the applicator head. The applicator head may have one or more openings in its surface through which additive may be passed. For example, the additive may he sprayed onto the additive release component in a liquid or gel format. Additives that are solid at room temperature may he melted or incorporated into a liquid vehicle such as methanol or ethanol. Those that are liquid at room temperature may he applied in pure form or dissolved or emulsified with another liquid. A simple admixture may also he suitable, for instance, an admixture of the additive and tile substrate. Tf the substrate is a porous material, the additive may seep into the pores of the material during the admixing step. This takes advantage of the high porosity of the porous material, thereby allowing a higher loading of the additive. Further processing steps may be employed, such as curing or pressure treatment.

The barrier material may be applied to the additive and/or substrate in the additive release component using any suitable technique known to the skilled person or described herein, which does not cause complete loss of the additive in the process. Preferably, substantially no additive is lost due to the step of 2 applying the barrier material. Tn an embodiment, the harrier material or a precursor thereto is sprayed onto the substrate, and optionally dried or treated to form a water-soluble film or gel on the surface.

Suitable amounts of substrate, additive and barrier material to use in the methods described herein will be known to the skilled person. For example, 5-mg of additive could be mixed with suitable proportions of substrate and any barrier material.

-22 -In the resulting product, the barrier material overlies the additive. For example, tile additive-carrying substrate may he encapsulated by the barrier material (as illustrated in Figure 6, for example). Alternatively, the additive may be covered by the harrier material and a surface of the substrate left uncovered by the barrier material (as illustrated in Figure 7, for example). In any of the embodiments described herein, migration of the additive from the substrate is hindered under ambient conditions prior to smoking by the presence of the barrier material. This should be contrasted with a comparative situation in which the additive is combined \vith barrier material before application to the substrate, such that in the resulting product the harrier material resides only in homogeneous admixture with the additive, or the additive has been pre-encapsulated with the barrier material before application to the substrate (and so is not in intimate contact with tile substrate).

In general, the additive release component may be inserted into the smoking article filter using any suitable method. Suitable apparatus may, for example, include a means for supplying a continuous stream of filter material from a source of such material (e.g., a hale, bobbin, or the like). The apparatus may further include an additive release component insertion unit for inserting or depositing the individual additive release components at predetermined intervals within the filter material. The filter material having additive release components deposited therein may then be received into a rod-making means for providing a continuous rod which may subsequently be subdivided into the desired length at 2 predetermined intervals to form individual filters.

Any suitable alternative technique may also be used if applicable. For example, the additive release component may he inserted into a cavity within the filter, or known dual or triple filter combining techniques may he used. The additive release component may be incorporated into the filter using a vertical feed method. fin

-L3 -The additive may be applied to the additive release component at any suitable stage in the production of the filter. For example, the additive may he applied during the manufacture of the additive release component and before incorporation into the filter. Tn this regard, the substrate may he directed through a solution of the additive, then through a solution of the barrier materia' and then into the filter material as it is condensed to form a filter. Alternatively, tile additive may he applied to the substrate by any other suitable method.

In some implementations, a wrapper such as a plugwrap surrounds the filter material, and is wrapped around the filter material by means of a garniture. The garniture comprises an endless or elongate garniture tape which drags the filter material comprising the additive release component through the garniture, shaping the wrapper such that the filter material is cylindrically wrapped. One or more adhesive applicators apply adhesive to the wrapper adjacent a longitudinal edge to secure the wrapper as a cylinder.

The length of filter rod may then be cut to provide filter elements for use alone as smoking article filters or in combination with one or more other filter elements in a composite filter. The length of the filter element will depend on the type of smoking article filter required. For example, a standard cigarette filter is about 27 mm in length. In the embodiments shown in accompanying Figures I, 2, 4 and 5, the whole 27 mm length of the filter includes or consists of the filter element, such that the additive release component extends the entire 2 length of the filter. flowever, in other embodiments, the filter element may comprise a section of a composite filter in combination with other filter elements, and in these embodiments, the filter element may be a shorter length as appropriate.

In use, negative pressure created by the user drawing on the buccal end of a filter comprising an additive release component as described herein has the effect of drawing smoke produced by the combustion of tobacco along the tobacco rod -24 -and through the filter, in preferred embodiments, as smoke passes through the filter, moisture in the smoke, or from the user's mouth, causes release of the additive from the additive release component. For example, in the embodiment illustrated in Figure 6, moisture causes the polyvinyl acetate, PVOH, methylcellulose or polysaccharide coating on the silicon to degrade. In other embodiments, it may be an increase in heat or a change in pH that causes release of the additive from the additive release component during smoking, as herein described. The pores in the silicon become uncovered, so allowing the flavourant to escape. The additive may then diffuse, or be drawn, from the additive release component into the flow of smoke for consumption by the user.

As the user manipulates the smoking article, additive may also pass from the smoking article to the user's fingers, where it may mask or absorb the odour of tobacco smoke.

The smoking article or smoking article filter may be ventilated, for example, by means of porous or perforated tipping paper. Preferably, a particular 7one or area is ventilated, for example by means of a narrow circumferential band of perforations. Due to the ventilating means, ventilating air is drawn into the smoking article when the user draws on the smoking article, and tins air may ntix with the mainstream smoke that is drawn from the rod of smokeable material.

The additive release component may he positioned close to the ventilating means. As a result, the additive may become entrained in the ventilating air as it 2 is drawn into the smoking article.

Preferably, the ventilation means is located at the upstream end of the filter or to the upstream of the filter. This is because diluting air tends to be drawn along the peripheral region of the filter, so that the additive release component extending along the filter core, where the smoke concentration is highest, increases the possibility of diffusion of additive from the additive release component most effectively and economically.

-25 -The use of a shaped additive release component, such as those shown in Figures 2 and 3, may further improve delivery of the additive. For example, an additive release component of the shape shown in Figure 2 may have an increased surLlce area exposed to the smoke being drawn through the filter relative to a more cylindrical component as sho\vn in Figure 1 An additive release component of the shape shown in Figure 3 may have an improved wicking effect compared to tile additive release component shown in Figure 1, resulting in the moisture in the smoke being drawn more quickly along its length. f0

Tile use of multiple additive release components, as illustrated in Figure 5, naturally permits a higher additive loading in the filter. Multiple additive release components arranged longitudinally may also improve the additive effect because the turbulence of the air being drawn through the smoking article is increased relative to a single additive release component of equivalent length. Increased turbulence results in greater interaction bet\veen the smoke and the surface of the additive release components, greater loss of the outer coating on the additive-containing pores and, therefore, increased distribution of the additive in the smoke being drawn through the filter.

It may be advantageous to include a small gap, or a short section of filter material such as cellulose acetate, for example of between about 0.5 and 5 mm, preferably between 1 mm and 2 mm in length, between the multiple additive release components, to introduce further turbulence into the smoke.

Passage of the additive into the desired regions of the smoking article may be further enhanced by means of, for example, absorbent material within the filter, and in particular, the use of absorbent material that is more absorbent than the remaining filter materia]. For example, absorbent material may be positioned adjacent to the additive release component within the filter in the area into which release of the additive from the additive release component is desired. In this way, the absorbent material may draw the additive in the desired direction.

-26 -Generally, as additive release components are located within the smoking article, it may he difficult for the user to release the additive in known additive release components. It may also he difficult for the user to determine whether or not the additive has been released. The additive release components described herein advantageously enable the additive to he more easily and reliably released than known additive release components, such as those that are responsive to mechanical force.

The additive release components described herein may also enhance availability of the additive material compared to known additive release components, due to their ability to control release of the additive. Better efficacy or higher performance may thus be achieved for the sante quantity of additive or the same performance may he achieved with a smaller amount of additive.

These advantages are believed to he demonstrated, in particular, by additive release components as described herein that are configured to release the additive in response to moisture.

Embodiments described above are configured to comply with applicable laws and/or regulations, such as, by way of non-limiting example, regulations relating to flavours, additives, emissions, constituents and/or the like. For example, the embodiments may he configured such that a smoking article implementing that described herein is compliant with applicable regulations before release of an 2 additive, after release of a first additive, and remains compliant after the release of one or more additional additives. Similarly, in embodiments where two or more additives react with each other to generate another substance, the generated substance complies with apphcahle laws/regulations.

Any and all combinations of substrate, additive and barrier materials as herein described are envisaged and encompassed. Thus, any structural configuration may be employed with any configuration of additive release.

-27 -Many other modifications and variations will be evident to those skilled in the art, that fall within the scope of the following claims.

Claims (1)

1. <claim-text>-28 -Claims 1. An additive release component for use in a smoking article comprising: a substrate; an additive supported by the substrate; and a barrier material overlying the additive and configured to release the additive from the substrate in response to a change in an environmental parameter.</claim-text> <claim-text>2. An additive release component as claimed in claim 1, wherein the change in an environmental parameter is: a) the presence of, or an increase in, moisture; h) an increase in heat; or c) a change in pH.</claim-text> <claim-text>3. An additive release component as claimed in claim 1 or claim 2, wherein the substrate comprises a porous material.</claim-text> <claim-text>4. An additive release component as claimed in claim 3, wherein the additive is contained within the pores of the porous material.</claim-text> <claim-text>5. An additive release component as claimed in claim 3 or claim 4, wherein tile porous material has a surface area of 10-500 m2/g, a porosity of 35-99%, a pore volume of at least 0.5 cc/g and/or a BET surface area of at least 1000 2 m2/g.</claim-text> <claim-text>6. An additive release component as claimed in any one of claims 3 to 5, wherein the porous material is nlesoporous or niacroporous silicon.</claim-text> <claim-text>7. An additive release component as claimed in any one of tile preceding claims, wherein the additive is a tiavourant.</claim-text> <claim-text>-29 - 8. An additive release component as claimed in any one of the preceding claims, wherein the loading of the additive on the additive release component is 80-95% by total weight of the additive release component.</claim-text> <claim-text>9. An additive release component as claimed in any one of the preceding claims, wherein the harrier material encapsulates the additive and the substrate.</claim-text> <claim-text>10. An additive release component as claimed in any one of the preceding claims, wherein the barrier material comprises polyvinyl acetate, polyvinyl alcohol, niethylcellulose, a polysaccharidc, pectin, VaX or poIyethyene glycol.ii. An additive release component as claimed in any one of the preceding claims, wherein the barrier material is soluble in water.12. An additive release coniponent substantially as hereinbefore described with reference to the Figures.13. A filter for a smoking article comprising an additive release component as claimed in any one of the preceding claims.14. A filter as claimed in claim 13, comprising more than one of said additive release components.15. A smoking article coniprising an additive release component as claimed in 2 any one of claims 1 to 12 or a filter as claimed in claim 13 or claim 14.</claim-text>