Electrostatically produced fast dissolving fibers

• US 20060264130A1
• Filed: 12/21/2005
• Published: 11/23/2006
• Est. Priority Date: 12/30/2004
• Status: Active Grant

• Current Assignee: Philip Morris USA Incorporated (Altria Group, Inc.)
• Original Assignee: Philip Morris USA Incorporated (Altria Group, Inc.)
• Inventors: Karles, Georgios D., Gee, Diane, Layman, John
• Granted Patent: US 7,856,989 B2
• Time in Patent Office: Days
• US Class Current: 442/59
• CPC Class Codes: A24B 15/282 by indirect addition of the chemical substances, e.g. in the wrapper, in the case
• CPC Class Codes: A24B 15/283 by encapsulation of the chemical substances
• CPC Class Codes: A24D 3/14 of organic materials as additive of ion exchange materials A24D3/12
• CPC Class Codes: D01D 5/0038 the fibre formed by solvent evaporation, i.e. dry electro-spinning
• CPC Class Codes: D01F 9/04 of alginates
• CPC Class Codes: D04H 13/00 Other non-woven fabrics
• CPC Class Codes: Y10T 442/20 Coated or impregnated woven, knit, or nonwoven fabric which is not [a] associated with another preformed layer or fiber layer or, [b] with respect to woven and knit, characterized, respectively, by a particular or differential weave or knit, wherein the coating or impregnation is neither a foamed material nor a free metal or alloy layer
• CPC Class Codes: Y10T 442/2303 Coating or impregnation provides a fragrance or releases an odor intended to be perceptible to humans
• CPC Class Codes: Y10T 442/2484 Coating or impregnation is water absorbency-increasing or hydrophilicity-increasing or hydrophilicity-imparting
• CPC Class Codes: Y10T 442/60 Nonwoven fabric [i.e., nonwoven strand or fiber material]
• CPC Class Codes: Y10T 442/614 Strand or fiber material specified as having microdimensions [i.e., microfiber]

Abstract

Fibrous structures composed of electrostatically prepared polysaccharide micro- and nanofibers are described which contain active agents such as drugs and/or flavorants encapsulated within the structures. When exposed to moisture, the structures are disrupted and the active agent rapidly released. The fibrous structures containing active agents such as flavorants can be incorporated into smoking articles which, when smoked, release the flavorants.

Claims

1. A method of producing polysaccharide fibers having a diameter ranging from about 1 nanometer to about 10 microns which comprises electrostatically processing an aqueous dispersion or solution containing a polysaccharide and an active agent and recovering a three-dimensional fibrous web comprising the polysaccharide encapsulating the active agent, wherein the polysaccharide is present in the solution or dispersion in an amount of about 20% to about 60% by weight, the polysaccharide comprises an alginate, a carrageenan, a gum, a pectin or pullulan, and the active agent comprises a pharmaceutical, flavorant, odorant, selective absorbent catalyst, protein or immobilized enzyme.

2. The method according to claim 1, wherein the polysaccharide comprises pullulan, the fibers are produced by electrospinning, and the active agent is a flavorant.

3. A non-woven three-dimensional fibrous structure comprising polysaccharide nano- or microfibers and the active agent encapsulated within the fibrous structure.

4. The non-woven fibrous structure of claim 3, wherein the polysaccharide comprises pullulan and the active agent comprises a pharmaceutical, a flavorant and/or an odorant.

5. The non-woven fibrous structure according to claim 4, wherein the odorant comprises at least one alcohol, acid, ester, aldehyde odorants, lactones, cyclic, bicyclic or acyclic terpenoid odorants, ionones, irones, damascones or pyrazines and the flavorant comprises menthol, eucalyptol, thymol, cumin oil, mint-type flavors, vanilla extracts, tobacco extracts, lemon or lime oil, dimethyl pyrazine, berry extracts or lemon grass.

6. The non-woven fibrous structure according to claim 5, wherein the flavorant comprises menthol.

7. The non-woven fibrous structure according to claim 3, wherein the polysaccharide fibers are cross-linked.

8. The non-woven three-dimensional fibrous structure according to claim 3, prepared by a process comprising electrospinning or electrospraying an aqueous composition containing a polysaccharide and the active agent and collecting the fibers on a collector.

9. The fibrous structure according to claim 8, wherein the aqueous composition contains at least one additive selected from viscosity modifiers, surfactants, pH buffers or cross-linking agents.

10. The fibrous structure according to claim 8, wherein the aqueous composition contains an additional polymer.

11. The fibrous structure according to claim 10, wherein the additional polymer comprises a cellulose ester.

12. A cigarette including a fibrous structure located in a filter of said cigarette and comprised of electrospun polysaccharide nano- or micro fibers having an active agent encapsulated within the fibrous structure.

13. The cigarette of claim 12, wherein the polysaccharide comprises pullulan and the active agent is a flavorant comprising menthol.

14. The cigarette of claim 12, wherein the polysaccharide comprises pullulan, an alginate, carageenan, gum, pectin, starch or a modified cellulose and the active agent is a flavorant comprising menthol, mint-flavored compounds, eucalyptol, berry extracts, citrus extracts or tobacco extracts.

15. The cigarette of claim 12, wherein the fibrous structure comprises a polymer in addition to the polysaccharide.

16. A method of treating mainstream tobacco smoke by drawing it into contact with the fibrous structure of claim 12 to expose the fibrous structure to moisture and thereby release the active agent.

17. A process for preparing a three-dimensional nonwoven fibrous structure which comprises:

(a) preparing an aqueous solution or aqueous dispersion comprising a polysaccharide and an active agent;

(b) electrostatically spinning or spraying the solution or dispersion through a capillary delivery device under the influence of an electric field; and

(c) collecting the spun or sprayed solution or dispersion on a collector in the form of said fibrous structure,

wherein the polysaccharide is present in the solution or dispersion in an amount ranging from about 20 to 60 wt. % and the active agent is present in an amount ranging from about 0.25 to 10 wt. %.

18. The process of claim 17, wherein the polysaccharide comprises an alginate, a carrageen, a gum, a pectin or pullulan and the active agent comprises a pharmaceutical and/or a flavorant.

19. The process of claim 17, wherein the aqueous solution or dispersion contains an additional polymer, the weight ratio of polysaccharide to polymer is about 25-75% to about 75-25%, the active agent is menthol, and the polysaccharide is pullulan.

20. The process of claim 17, wherein the fibrous structure is reacted with a cross-linking agent.

21. A filter of a smoking article comprising a fibrous structure composed of electrospun polysaccharide nano-or-micro fibers having an active agent encapsulated within the fibrous structure.

22. The filter of claim 21, wherein (a) the fibrous structure comprises a polymer in addition to the polysaccharide or (b) the polysaccharide comprises pullulan, alginates, carageenans, gums, pectins, starch and modified celluloses and the active agent is a flavorant comprising menthol, mint-flavored compounds, eucalyptol, berry extracts, citrus extracts or tobacco extracts.

23. The filter of claim 22, wherein the polymer comprises a cellulose ester.

24. The filter of claim 21, located in a cigarette, wherein the polysaccharide comprises pullulan and the active agent is a flavorant comprising menthol.

25. A cigarette comprising the filter of claim 21, wherein a sorbent is located upstream of the fibrous structure.