Method for making a carbonaceous heat source containing metal oxide

• US 5,595,577 A
• Filed: 05/19/1995
• Issued: 01/21/1997
• Est. Priority Date: 06/02/1993
• Status: Expired due to Term

• Current Assignee: Philip Morris USA Incorporated (Altria Group, Inc.), Philip Morris Products SA (Philip Morris Limited)
• Original Assignee: Philip Morris USA Incorporated (Altria Group, Inc.), Philip Morris Products SA (Philip Morris Limited)
• Inventors: Deevi, Sarojini, Deevi, Seetharama C., Schleich, Donald M., Bensalem, Azzedine
• Primary Examiner(s): MEDLEY, MARGARET B
• Application Number:
  US08/444,943
• Time in Patent Office: 613 Days
• Field of Search: 44/591, 44/598, 44/599, 44/504, 44/542, 44/629, 131/330, 131/194, 131/337, 131/369
• US Class Current: 44/629
• CPC Class Codes: A24B 15/165 comprising as heat source a carbon fuel or an oxidized or thermally degraded carbonaceous fuel, e.g. carbohydrates, cellulosic material
• CPC Class Codes: Y02E 50/30 Fuel from waste, e.g. synthetic alcohol or diesel

Abstract

A carbonaceous heat source comprising metal oxides and methods for making such heat source are provided. The heat source has an ignition temperature substantially lower than conventional carbonaceous heat sources, while at the same time produces virtually no carbon monoxide upon combustion. The heat source is prepared by pre-forming the carbon and binder materials into a desired shape, and then treating the shape with a sol containing metal oxide precursors. The metal oxide precursors are deposited in the pre-formed carbon shape. Further treatment converts the deposited metal oxide precursors into metal oxide.

Claims

1. A smoking article comprising:

a carbonaceous heat source made according to the method comprising the steps of;

a) mixing a hydroxylated organic chemical, wherein the hydroxylated chemical compound is selected from the group consisting of diols and triols, and a metal oxide precursor to form a sol, wherein the metal oxide precursor is selected such that the formed metal oxide is an iron oxide, the metal oxide capable of reducing an amount of carbon monoxide produced upon combustion of the carbonaceous material;

b) heating the mixture from step a) to form a polymeric or oligomeric species containing the selected metal and organic species;

c) treating a carbonaceous material with the sol; and

d) heating the product of step e) to evaporate liquid from the sol and then decompose the polymeric or oligomeric species of the sol to form the metal oxide to form a heat source comprising the carbonaceous material and the metal oxide,

wherein said carbonaceous heat source is formed into a shape which fits within the smoking article and gases flow past or through it to be heated, and,

a flavor bed which is then heatable by the thus heated gases to release flavor, whereby flavor is provided to a smoker.

2. The smoking article according to claim 1, wherein the hydroxylated organic chemical is selected from the group consisting of ethylene glycol and propylene glycol.

3. The smoking article according to claim 1, wherein the carbonaceous material of step c) is treated with the sol for between about 1 minute and about 10 minutes.

4. The smoking article according to claim 1, wherein the carbonaceous material of step c) is treated with the sol by painting, immersing or dipping.

5. The smoking article according to claim 1, wherein the carbonaceous material of step c) is treated with the sol by spraying.

6. The smoking article according to claim 5, wherein the carbonaceous material is transported in a continuous fashion during step c) and step d).

7. The smoking article according to claim 1, wherein the product of step c) is heated at between about 150°

C. and about 300°

C. for about 60 minutes.

8. The smoking article according to claim 1, wherein the carbonaceous material of step c) is a carbon rod, wherein the carbon rod has a length of about 30 cm an a diameter of between about 3.0 mm and about 8.0 mm.

9. The smoking article according to claim 1, wherein the weight increase of the product of step d) over the carbonaceous material of step c) before treatment with the sol is between about 0.1% and about 20%.

10. The smoking article according to claim 1, wherein the weight increase of the product of step d) over the carbonaceous material of step c) before treatment with the sol is between about 2% and about 15%.

11. The smoking article according to claim 1, wherein the weight increase of the product of step d) over the carbonaceous material of step c) before treatment with the sol is between about 4% and about 8%.

12. The smoking article according to claim 1, wherein the density of the product of step d) is between about 0.5 gm/cc and about 1.5 gm/cc.

13. The smoking article according to claim 1, wherein the density of the product of step d) is between about 0.4 gm/cc and about 2.25 gm/cc.

14. The smoking article according to claim 1, wherein the product of step c) is heated between about 100°

C. and about 400°

C. for about ninety minutes.

15. The smoking article according to claim 1, wherein the metal oxide precursor is selected such that the metal oxide is ferric oxide.

16. The smoking article according to claim 1, wherein the particle size of the carbonaceous material is ≦

300μ

.

17. The smoking article according to claim 1, wherein the density of the product of step d) is ≦

2.25 gm/cc.

18. The smoking article according to claim 1, wherein step b) comprises heating the mixture from step a) to between about 60°

C. and about 150°

C.

19. The smoking article according to claim 18, wherein the product of step c) is heated between about 100°

C. and about 400°

C. for about ninety minutes.

20. The smoking article according to claim 1, wherein the carbonaceous material of step c) is treated with the sol for between about five minutes and about ten minutes.

21. The smoking article according to claim 1, wherein the weight increase of the product of step d) over the carbonaceous material of step c) before treatment with the sol is between about 4% and about 6%.

22. The smoking article according to claim 1, wherein the surface area of the carbonaceous material is between about 200 m² /gm and 800 m² /gm.

23. The smoking article according to claim 1, wherein the metal oxide precursor is hydrated iron nitrate.

24. The smoking article according to claim 1, wherein the metal oxide precursor is iron nitrate.

25. The smoking article according to claim 1, wherein the metal oxide precursor is iron oxalate.

26. The smoking article according to claim 1, wherein the metal oxide precursor is iron acetyl acetonate.

27. The smoking article according to claim 1, wherein the carbonaceous material further comprises a burn additive.

28. The smoking article according to claim 27, wherein the burn additive is selected from the group consisting of perchlorates, chlorates, nitrates, and permanganates.

29. The smoking article according to claim 1, wherein the surface area of the carbonaceous material is between about 0.5 m² /gm and 2000 m² /gm.

30. The smoking article according to claim 1, wherein the surface area of the carbonaceous material is between about 100 m² /gm and 800 m² /gm.

31. The smoking article according to claim 1, wherein the surface area of the metal oxide is between about 4.0 m² /g and 200 m² /g.

32. The smoking article according to claim 1, wherein the particle size of the metal oxide is between about 200 Å

and 40μ

.

33. The smoking article according to claim 1, wherein the particle size of the metal oxide is between about 800 Å

and 5μ

.