HYDROPHOBIC WRAPPER

Abstract

A smoking article (10) includes a tobacco substrate (20) comprising at least 15% humectant and a hydrophobic paper wrapper (40) disposed about the tobacco substrate. The paper wrapper (40) is hydrophobic due to hydrophobic groups covalently bonded to the paper.

Claims

1. A smoking article comprising: a tobacco substrate comprising at least 15% humectant; and a paper wrapper disposed about the tobacco substrate, wherein the paper wrapper is hydrophobic due to hydrophobic groups covalently bonded to the paper.

2. A smoking article according to claim 1, wherein the paper wrapper maintains the tobacco substrate in cylindrical form and the tobacco substrate comprises at least 20% humectant.

3. A smoking article according to claim 1, wherein the paper wrapper has a water contact angle of at least about 100 degrees.

4. A smoking article according to claim 1, wherein the paper wrapper comprises cellulosic material and a hydrophobic group covalently bonded to the cellulosic material.

5. A smoking article according to claim 3, wherein the paper wrapper has a basis weight in a range from about 20 to about 50 grams per square meter and the hydrophobic reagent has a basis weight in a range from about 0.1 to about 3 grams per square meter.

6. A smoking article according to claim 1, wherein the hydrophobic group is covalently bonded to cellulosic material of the paper by reacting in situ a fatty acid chloride with the cellulosic material.

7. A smoking article according to claim 6, wherein the hydrophobic paper comprises fatty acid esters of cellulose.

8. A smoking article according to claim 6, wherein the fatty acid chloride is palmitoyl chloride, stearoyl chloride, behenoyl chloride, or a mixture of palmitoyl chloride and stearoyl chloride.

9. A smoking article according to claim 1, wherein the wrapper exhibits a Cobb measurement value (60s) of less than 20 g/m.sup.2.

10. A smoking article according to claim 1, wherein the hydrophobic paper is produced by a process comprising the steps of: applying a liquid composition comprising a fatty acid halide to at least one surface of a paper, maintaining the surface at a temperature of about 120° C. to about 180° C., wherein the fatty acid halide reacts in situ with protogenic groups of material in the paper resulting in the formation of fatty acid esters.

11. A smoking article according to claim 10, wherein the process comprises applying a liquid composition comprising stearoyl chloride or palmitoyl chloride to at least one surface of a paper at a temperature of about 120° C. to about 180° C., wherein hydroxyl groups in the cellulosic material of the paper reacts in situ with the stearoyl chloride or palmitoyl chloride.

12. A smoking article according to claim 10, wherein the process comprises applying the liquid composition to the at least one surface of a paper at a rate of in a range from about 0.1 to about 3 grams per square meter to render the at least one surface of a the paper hydrophobic.

13. A method of forming a smoking article according to any of the preceding claims claim 1 comprising reacting a fatty acid chloride with the cellulosic material of the paper wrapper to form a hydrophobic paper wrapper.

14. A method according to claim 13 wherein the reacting step comprises printing fatty acid chloride, which provides a fatty acid ester group or a fatty acid group that bonds with pendent hydroxyl groups on the cellulosic material of the wrapper to form a hydrophobic wrapper.

15. An aerosol-generating system comprising: an aerosol-generating device comprising a heating element; and an aerosol-generating smoking article according to claim 1; wherein the aerosol-generating device is configured to releasably receive the aerosol-generating smoking article and the heating element provides heat to the aerosol-forming substrate of a heated smoking article.

16. A smoking article according to claim 4, wherein the paper wrapper has a basis weight in a range from about 20 to about 50 grams per square meter and the hydrophobic reagent has a basis weight in a range from about 0.1 to about 3 grams per square meter.

17. A smoking article according to claim 11, wherein the process comprises applying the liquid composition to the at least one surface of a paper at a rate of in a range from about 0.1 to about 3 grams per square meter to render the at least one surface of a the paper hydrophobic.

18. A method according to claim 13, wherein the reacting step comprises reacting a fatty acid chloride with the cellulosic material of the paper wrapper to form a hydrophobic paper wrapper and the fatty acid halide is palmitoyl chloride, stearoyl chloride, behenoyl chloride, or a mixture of palmitoyl chloride and stearoyl chloride.

19. A method according to claim 13, wherein the reacting step comprises applying the fatty acid chloride to the at least one surface of a paper at a rate of in a range from about 0.1 to about 3 grams per square meter to render the at least one surface of a the paper hydrophobic.

20. A method according to claim 13, wherein the reacting step comprises applying a liquid composition comprising a fatty acid halide to at least one surface of the paper wrapper, maintaining the surface at a temperature of about 120° C. to about 180° C., wherein the fatty acid halide reacts in situ with protogenic groups of material in the paper wrapper resulting in the formation of fatty acid esters to form the hydrophobic paper wrapper.

Description

[0067] The smoking articles depicted in FIGS. 1-2 illustrate one or more embodiments of smoking articles or components of smoking articles described above. The schematic drawings are not necessarily to scale and are presented for purposes of illustration and not limitation. The drawings depict one or more aspects described in this disclosure. However, it will be understood that other aspects not depicted in the drawings fall within the scope and spirit of this disclosure.

[0068] Referring now to FIG. 1, a smoking article 10 is depicted. The smoking article 10 includes a tobacco substrate 20, such as a tobacco rod having a high level of humectant, and a mouth end segment 30 and a distal end 70. The mouthpiece 30 can abut the tobacco substrate 20 in the finished smoking article 10. The depicted smoking article 10, includes a plug wrap 60 that circumscribes at least a portion of the filter or mouthpiece segment 30 and a hydrophobic wrapper 40 that circumscribes at least a portion of the tobacco substrate 20. Tipping paper 50 or other suitable wrapper circumscribes the plug wrap 60 and a portion of the wrapper 40 as is generally known in the art.

[0069] The exemplary aerosol-generating article 100 comprises elements arranged in coaxial alignment: an aerosol-forming substrate 120, an aerosol-cooling element 140, and a mouthpiece 150. These four elements are arranged sequentially and are circumscribed by a hydrophobic wrapper 160 to form the aerosol-generating article 100. The aerosol-generating 100 has a proximal or mouth end 170, which a user inserts into his or her mouth during use, and a distal end 180 located at the opposite end of the aerosol-generating article 100 to the mouth end 170. In use, air is drawn through the aerosol-generating article 100 by a user from the distal end 180 to the mouth end 170.

[0070] The aerosol-forming substrate 120 can be located at the extreme distal or upstream end of the aerosol-generating article 100. In the embodiment illustrated in FIG. 2, aerosol-forming substrate 120 comprises homogenised tobacco material and a humectant such as glycerine as the aerosol-former.

[0071] Additional elements such as support elements to prevent the aerosol-forming substrate 120 from being forced downstream within the aerosol-generating article 100 towards the aerosol-cooling element 140 when a heating element 220 of an aerosol-generating device 210 is inserted into the aerosol-forming substrate 120, can be included (not shown).

[0072] The aerosol-cooling element 140 is located downstream of the aerosol-forming substrate 120. In use, volatile substances released from the aerosol-forming substrate 120 pass along the aerosol-cooling element 140 towards the mouth end 170 of the aerosol-generating article 100. The mouthpiece 150 is located downstream of the aerosol-cooling element 140 and can include a conventional cellulose acetate tow filter of low filtration efficiency.

[0073] The aerosol-generating device comprises a heating element 220. The heating element 220 can be mounted within an aerosol-generating article receiving chamber 205 of the aerosol-generating device 210. In use, the user inserts the aerosol-generating article 100 into the aerosol-generating article receiving chamber 205 of the aerosol-generating device 210 such that the heating element 220 is directly inserted into the aerosol-forming substrate 120 of the aerosol-generating article 100. In the embodiment shown in FIG. 3, the heating element 220 of the aerosol-generating device 210 is a heater blade.

[0074] In FIG. 2, the components of the aerosol-generating device 210 are shown in a simplified manner and not drawn to scale. The aerosol-generating device 210 comprises a housing that contains a power supply 240 and electronics 250 that allow the heating element 220 to be actuated. The heating element 220 is mounted within an aerosol-generating article receiving chamber 205 within the housing. The aerosol-generating article 100 is inserted into the aerosol-generating article receiving chamber 205 such that the heating element 220 is directly inserted into the aerosol-forming substrate 120 of the aerosol-generating article 100.

[0075] The aerosol-generating device 210 comprises an electrical energy supply 240, for example a rechargeable lithium ion battery. A controller 250 is connected to the heating element 220, the electrical energy supply 240, and a user interface 260, for example a button or display. The controller 250 controls the power supplied to the heating element 220 in order to regulate its temperature.

[0076] Once the aerosol-generating article 100 is releasably received in the aerosol-generating device 210 and on the heating element 220, the aerosol-generating device 210 is actuated to heat the aerosol-forming substrate 120 to a temperature of approximately 375 degrees Celsius. As a user draws on the mouth end 170 of the aerosol-generating article 100, the volatile compounds evolved from the aerosol-forming substrate 120 are drawn downstream through the aerosol-generating article 100 and condense to form an aerosol that is drawn through the mouthpiece 150 of the aerosol-generating article 100 into the user's mouth. The hydrophobic wrapper 160 repels humectant and moisture from the aerosol to reduce staining and weakening of the wrapper 160.

[0077] The exemplary embodiments described above are not limiting. Other embodiments consistent with the exemplary embodiments described above will be apparent to those skilled in the art.