ES2417029T3 - Treated tobacco - Google Patents

Abstract

Treated tobacco (1) for an article for smoking, where the tobacco (2) carries diluent (3) and barrier material (4), where the diluent (3) has been applied to tobacco (2) before or simultaneously with the barrier material (4), wherein the barrier material (4) is substantially external to the diluent (3).

Description

Treated tobacco

The present invention relates to treated tobacco material. In particular, the present invention relates to tobacco bearing diluent and barrier material, to products comprising them and to a process for producing them.

It is known that diluents are included in smoking articles such as cigarettes. Diluents are compounds that evaporate when smoking and are transferred to the mainstream of smoke in the form of an aerosol. They are generally selected so that they are transferred substantially intact to the smoke. Therefore, the other smoke components (tobacco-derived components in the case of tobacco-containing smoking articles) are "diluted" by this means.

A cigarette may comprise a filter at the end of the mouth, a tobacco cylinder comprising smokable filler material, and cigarette paper wrapped around the cylinder. When a diluent is present in the smokable filler material, it may be as a simple mixture with the other ingredients (particularly for diluents in solid form), or the diluent may be carried on one or more of the other ingredients (particularly if the diluent It is in liquid form). If it is incorporated into the filler material as a simple mixture, this may present drawbacks during manufacturing, and the diluent can be easily removed from the finished product, especially if it is in the form of fine powder. Therefore, it is preferred that the diluent be kept in intimate contact with another ingredient of the filler material.

It is known that the diluent is provided in intimate contact with the tobacco itself. For example, WO 2007/012980 and US 2006/283469 describe a tobacco-containing composition comprising added diluents, which can be administered by spraying, mixing or soaking the tobacco.

It has been found that, although the diluent evaporates when smoking in the course of performing this function, evaporation of the diluent at lower temperatures can cause problems during cigarette storage. Specifically, the diluent may migrate during storage and may subsequently be lost to the atmosphere or interact with other parts of the product such as cigarette paper. This can also lead to staining or the formation of cigarette paper marks, both by the diluent itself and by compounds that are released from the interaction of the diluent.

Therefore, there is a need in the art to prevent migration of the diluent during storage of the cigarette or other smoking article.

Accordingly, the inventors of the present have created the invention defined in the claims.

Figure 1 is a schematic illustration of a particle of treated tobacco found in tobacco treated in accordance with an embodiment of the invention.

Figure 2 is a schematic illustration of a particle of treated tobacco found in tobacco treated in accordance with another embodiment of the invention.

Figure 3 is a schematic illustration of another particle of treated tobacco.

The tobacco used in the invention can be, for example, stalk, sheet, powder, reconstituted tobacco or a mixture thereof. Suitable tobacco materials include the following types of tobacco: Virginia or hot air cured tobacco, Burley tobacco, Oriental tobacco, or a mixture of tobacco materials. Tobacco can be expanded, such as tobacco expanded with dry ice (DIET), or processed by any other means such as extrusion. The stem tobacco can be preprocessed or unprocessed, and can be, for example, solid stems, dried chopped stems, or stems treated with steam.

The diluent is at least one aerosol forming agent that can be, for example, a polyol aerosol generator.

or a non-polyol aerosol generator, preferably a non-polyol aerosol generator. It may be solid or liquid at room temperature, but preferably it is liquid at room temperature. Suitable polyols include sorbitol, glycerol, and glycols such as propylene glycol or triethylene glycol. Suitable non-polyols include monohydric alcohols, high boiling hydrocarbons, acids such as lactic acid, and esters such as diacetin, triethyl triacetin citrate or isopropyl myristate. A combination of diluents can be used, in equal or different proportions. Particularly preferred are triacetin, triethyl citrate and isopropyl myristate.

The application of the diluent to tobacco is done by any suitable procedure known to a skilled person, including washing, soaking, spraying or mixing.

The diluent can be seated as a surface coating on the tobacco material, and / or at least something can be absorbed into the material. However, in the present invention it is not essential that the diluent be in a precise location on the tobacco.

There may be several factors that influence the stability and migration of diluents under conditions 2

environmental. These factors may include hydrophobia or hydrophilicity, viscosity, saturated vapor pressure at room temperature, boiling point, molecular structure (such as hydrogen bonding or Van der Waals forces) and the absorption / adsorption interaction between the diluent and the tobacco. Some diluents will present migration problems of greater magnitude than others; for example, it has been found that triacetin, isopropyl myristate and triethyl citrate take particular advantage of the immobilization according to the present invention.

Another relevant factor is the diluent charge level. For example, if a diluent such as glycerol is included in large quantities, migration problems can also be significant.

The level of diluent charge in the present invention may depend on the specific diluent. However, preferably, the treated tobacco of the invention carries at least 0.05 g of diluent per g of tobacco, more preferably at least 0.1 g of diluent per g of tobacco, more preferably at least 0.2 g of diluent per g of tobacco. In terms of the total weight of the treated tobacco, it preferably contains at least 5% by weight of diluent, preferably at least 10%, 15%, 20% or 50%.

The barrier material is capable of inhibiting the migration of the diluent during the storage of the smoking article but allows the diluent to be released by smoking the smoking article. It can be one that melts, decomposes, reacts, degrades, swells or deforms to release the diluent at a temperature above room temperature but at a temperature equal to or less than that achieved when smoking within the article to smoke. For example, the physical expansion that occurs with the evaporation of sufficient levels of diluent can break the structure of the barrier material. In embodiments of the invention, the barrier material releases substantial amounts of the diluent above 50 ° C, preferably above 60 ° C, 70 ° C, 80 ° C or 90 ° C.

The barrier material may be, for example, a polysaccharide or a cellulosic barrier material, a gelatin, a gum, a gel or a mixture thereof. Suitable polysaccharides include alginate, dextran, maltodextrin, cyclodextrin and pectin. Suitable cellulosic materials include methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, and cellulose ethers. Suitable gums include gum arabic, ghatti gum, tragacanth gum, karaya, garrofín gum, acacia, guar, quince seed and xanthan gums. Suitable gels include agar, agarose, carrageenans, furoidan and furcellaran.

In a preferred embodiment of the invention, the barrier material comprises a polysaccharide. An alginate is especially preferred, due to its encapsulation properties. The alginate can be, for example, a salt of alginic acid, an esterified alginate or glyceryl alginate. Alginic acid salts include ammonium alginate, triethanolamine alginate, and metal ion alginates of groups I and II such as sodium, potassium, calcium and magnesium alginate. The esterified alginates include propylene glycol alginate and glyceryl alginate.

In one embodiment, the barrier material is sodium alginate and / or calcium alginate. Calcium alginate provides greater inhibition of diluent migration at room temperature than sodium alginate, but it can also release the diluent at a higher temperature than the latter.

The diluent is applied to tobacco before or simultaneously with the barrier material. Preferably, the diluent is in intimate contact with the tobacco.

The application of the barrier material is done by any suitable procedure known to an expert or described herein, which does not cause the complete loss of the diluent in the process. Preferably, substantially no diluent is lost due to the stage of application of the barrier material. In one embodiment, the process of the invention involves spraying the barrier material or a precursor thereof.

For example, tobacco can be sprayed with an aqueous solution of sodium alginate and dried to form a water soluble film on the surface. The calcium ions of the tobacco itself can at least partially gel the sodium alginate to calcium alginate. Calcium ions can be added to tobacco before alginate treatment to enhance this effect. Alternatively, the tobacco can be sprayed with sodium alginate and then treated with a source of calcium ions to form a water insoluble film or a calcium alginate gel coating.

In the product resulting from the invention, the diluent is surrounded by the barrier material and its migration is prevented under ambient conditions. A schematic illustration of a particle of treated tobacco found in an embodiment of the invention is presented in Figure 1. In this embodiment, the treated tobacco particle (1) is a tobacco particle (2) containing diluent (3) in a first coating and optionally also in its cellular structure. "Pores" (5) or air gaps between tobacco fibers are shown; Although the diluent (3) is shown coating a pore, it can completely fill the pore. The barrier material (4) forms an outer coating around the tobacco particle. In practice, the dividing line between the barrier material layer and the diluent layer may not necessarily be sharp, but the barrier material will be substantially external to the diluent.

Another treated tobacco particle (10) of the invention is shown in Figure 2, in which the barrier material and the

Diluent have been applied together to tobacco and settle within the cellular structure and / or as a coating layer (31) on the surface of the particle. In one embodiment, a further coating of barrier material (4) is then applied to provide an additional barrier to migration.

In one embodiment, the invention excludes treated tobacco in which the diluent has been pre-encapsulated with the

5 barrier material before application to tobacco. This is illustrated by the tobacco particle (100) in Figure 3, in which the diluent (3) has been pre-encapsulated with the barrier material (4) before application to tobacco (2), and from this way is not in intimate contact with tobacco.

In the invention, the treated tobacco contains all the barrier material that is required to perform its function. This will depend on the type of tobacco used. For example, when using dry bite stalk, treated tobacco

10 may contain 1-10% by weight of the barrier material, optionally 3-8% by weight, optionally 4-6% by weight. As will be appreciated by those skilled in the art, the amount of barrier material by weight of expanded tobacco will be greater, for example, than with a dry bite stalk.

The treated tobacco can be incorporated into an article for smoking by conventional means. It may be the only tobacco used in the smoking article or it may be combined or mixed with other tobacco materials. How

15 used herein, the term "smoking article" includes smokable products such as cigarettes, cigars, and cigarettes. The term also includes what are called "warming-without-burning" products, which produce smoke or a smoke-like spray. The smoking article can be supplied with a filter for the gas stream and particulate matter carried by the smoker. Preferably, the smoking article is a cigarette.

Claims (10)

1. Treated tobacco (1) for a smoking article, where the tobacco (2) carries diluent (3) and barrier material (4), where the diluent (3) has been applied to tobacco (2) before or simultaneously with the barrier material (4), wherein the barrier material (4) is substantially external to the diluent (3). Treated tobacco (1) as described in claim 1, wherein the diluent (3) is in intimate contact with the tobacco (2). 3. Treated tobacco (1) as described in any of the preceding claims, wherein the barrier material (4) comprises an alginate. 4. Treated tobacco (1) as described in any of the preceding claims, containing 1-10% by weight of barrier material (4).

5.

Treated tobacco (1) as described in any of the preceding claims, containing at least 0.05 g of diluent (3) per 100 g of tobacco (2).

6.

Treated tobacco (1) as described in any of the preceding claims, which contains at least 5% by weight diluent (3).

Treated tobacco (1) as described in any of the preceding claims, wherein the diluent (3) is triacetin, triethyl citrate, or isopropyl myristate.

8.

A smoking article containing treated tobacco (1) as described in any of the preceding claims.

9.

A process for producing treated tobacco (1) for an article for smoking, which comprises treating tobacco (2)

20 with a diluent (3) before or simultaneously with the treatment of tobacco (2) with a barrier material (4), wherein the barrier material (4) is substantially external to the diluent (3). 10. A process as described in claim 9, wherein the diluent (3) is applied to tobacco (2) before application of the barrier material (4). 11. A process as described in claim 9 or 10, wherein the diluent (3) is sprayed onto tobacco (2). 12. A process as described in any one of claims 9 to 11, wherein the barrier material (4) is sprayed on the tobacco (2).