Thermoplastic cigarette wrapper

• US 4,020,850 A
• Filed: 07/17/1975
• Issued: 05/03/1977
• Est. Priority Date: 12/12/1973
• Status: Expired due to Term

• Current Assignee: Brown & Williamson Tobacco Corporation (British American Tobacco PLC)
• Original Assignee: Brown & Williamson Tobacco Corporation (British American Tobacco PLC)
• Inventors: Cogbill, Philip Hancock II
• Primary Examiner(s): Michell, Robert W.
• Assistant Examiner(s): Gron, T. S.
• Application Number:
  US05/596,850
• Time in Patent Office: 656 Days
• Field of Search: 131/2, 131/15 R, 131/17 R, 131/140 R, 131/140 C, 131/142-144, 162/139
• US Class Current: 131/334
• CPC Class Codes: A24D 1/02 with special covers

Abstract

A cigarette wrapper comprising a microporous sheet formed from a cellulose derivative binder filled with finely ground paper. The wrapper also includes a small amount of potassium nitrate. Such cigarette wrappers are effective to selectively reduce the nicotine delivery from normal cigarette tobacco blends.

Claims

1. A thin, microporous cigarette wrapper sheet having a porosity of between about 5-60 Greiner and in which at least 50 percent of the pores of said sheet have a diameter of no more than 3 microns, said sheet comprising:

(a) about 10 percent to about 45 percent by weight finely divided unfilled paper having a size of 140 mesh or less;

(b) about 1.5 percent to about 2.8 percent by weight potassium nitrate;

(c) up to about 40 percent by weight of a whitener; and

(d) about 20 percent to about 55 percent by weight of a thermoplastic binder selected from the group consisting of cellulose esters, cellulose ethers, and mixtures thereof.

2. The thin, microporous sheet of claim 1 which comprises about 20 percent to about 30 percent by weight of said finely divided paper.

3. The thin, microporous sheet of claim 1 which comprises about 1.7 percent to about 2.5 percent by weight of said potassium nitrate.

4. The thin, microporous sheet of claim 1 which comprises about 15 percent to about 30 percent by weight of said whitener.

5. The thin, microporous sheet of claim 1 in which said whitener is selected from the group consisting of calcium carbonate, magnesium carbonate, aluminum hydroxide, talc, and titanium dioxide.

6. The thin, microporous sheet of claim 1 in which said whitener is titanium dioxide.

7. The thin, microporous sheet of claim 1 which comprises about 30 percent to about 40 percent by weight of said binder.

8. The thin, microporous sheet of claim 1 in which said binder is a mixture of methyl cellulose and cellulose acetate.

9. The thin, microporous sheet of claim 8 in which the ratio of cellulose acetate to methyl cellulose is between 2:

1 and 20;

1 parts by weight.

10. The thin, microporous sheet of claim 1 which includes from about 2 percent to about 15 percent by weight of a plasticizer.

11. The thin, microporous sheet of claim 10 which includes from about 6 percent to about 12 percent by weight of a plasticizer.

12. The thin, microporous sheet of claim 10 in which said plasticizer is a mixture of 1,3-butylene glycol, propylene glycol and glycerin.

13. A thin, microporous cigarette wrapper sheet having a porosity of between about 10-30 Greiner and in which at least 50 percent of the pores of said sheet have a diameter of no more than 3 microns said sheet comprising:

(a) about 20 percent to about 30 percent by weight finely divided unfilled paper having a size of 140 mesh or less;

(b) about 1.7 percent to about 2.5 percent by weight potassium nitrate;

(c) about 15 percent to about 30 percent by weight titanium dioxide;

(d) about 2 percent to about 15 percent by weight of a plasticizer; and

(e) about 30 percent to about 40 percent by weight of a thermoplastic binder selected from the group consisting of cellulose esters, cellulose ethers and mixtures thereof.

14. The thin, microporous sheet of claim 13 in which said binder comprises from 2 to 20 parts by weight cellulose acetate and one part by weight methyl cellulose.

15. A smoking article comprising a smokeable material contained within the thin, microporous sheet of claim 13.

16. A smoking article comprising a smokeable material contained with a thin, microporous cigarette wrapper sheet having a porosity of between about 5-60 Greiner and in which at least 50 percent of the pores of said sheet have a diameter of no more than 3 microns said sheet comprising:

(a) about 10 percent to about 45 percent by weight finely divided unfilled paper having a size of 140 mesh or less;

(b) about 1.5 percent to about 2.8 percent by weight potassium nitrate;

(c) up to about 40 percent by weight of a whitener; and

(d) about 20 percent to about 55 percent by weight of a thermoplastic binder selected from the group consisting of cellulose esters, cellulose ethers and mixtures thereof.

17. The smoking article of claim 16 in which said wrapper comprises about 20 percent to about 30 percent by weight of said finely divided paper.

18. The smoking article of claim 16 in which said wrapper comprises about 1.7 percent to about 2.5 percent by weight of said potassium nitrate.

19. The smoking article of claim 16 in which said wrapper comprises about 15 percent to about 30 percent by weight of said whitener.

20. The smoking article of claim 16 in which said whitener of said wrapper is selected from the group consisting of calcium carbonate, magnesium carbonate, aluminum hydroxide, talc, and titanium dioxide.

21. The smoking article of claim 20 in which said whitener is titanium dioxide.

22. The smoking article of claim 16 in which said wrapper comprises about 30 percent to about 40 percent by weight of said binder.

23. The smoking article of claim 16 in which said binder of said wrapper comprises a mixture of methyl cellulose and cellulose acetate.

24. The smoking article of claim 16 in which said wrapper includes from about 2 percent to about 15 percent by weight of a plasticizer.

25. The smoking article of claim 24 which includes from about 6 percent to about 12 percent by weight of a plasticizer.

26. The smoking article of claim 24 in which said plasticizer comprises a mixture of 1,3-butylene glycol, propylene glycol and glycerin.