Smoking Articles with Reduced Ignition Proclivity Characteristics

Abstract

A process for reducing the permeability of a paper wrapper used in the construction of a smoking article is disclosed. The paper wrapper is treated with a film-forming composition that forms treated discrete areas on the wrapper. The treated discrete areas have a permeability within a predetermined range sufficient to reduce the ignition proclivity properties of a smoking article made with the wrapper. In accordance with the present invention, the film-forming composition contains a film-forming material. The film-forming material has a relatively low viscosity. In this manner, the film-forming composition can have a relatively high solids content and still be applied to the wrapper using conventional techniques, such as by using a gravure printer.

What is claimed is: 
     
         1 . A process for producing a paper wrapper having reduced ignition proclivity characteristics when incorporated into a smoking article comprising:
 applying a film-forming composition to a paper wrapper at particular locations in an amount from about 1% to about 15% by weight, the film-forming composition including a film-forming material comprising at least one of alginate, guar gum, pectin, polyvinyl alcohol, a cellulose derivative, starch, a starch derivative, or mixtures thereof, the film-forming material having a molecular weight such that the film-forming material has a viscosity of less than about 500 cP when present in a 3% by weight aqueous solution at 25° C., the film-forming composition forming treated discrete areas on the paper wrapper, the treated discrete areas being separated by untreated areas, the treated discrete areas having a BMI of less than 5 cm −1 , the treated areas having a permeability of less than about 40 Coresta, the untreated areas of the paper wrapper having a permeability of less than about 55 Coresta.   
     
     
         2 . The process of  claim 1 , wherein the untreated areas of the paper wrapper have a permeability of less than about 30 Coresta. 
     
     
         3 . The process of  claim 1 , wherein the untreated areas of the paper wrapper have a permeability ranging from about 15 Coresta to less than about 55 Coresta. 
     
     
         4 . The process of  claim 1 , wherein the film-forming material is present in the composition such that the film-forming composition has a solids content of at least 6% by weight. 
     
     
         5 . The process of  claim 1 , wherein the treated areas have a BMI of from about 1 cm −1  to about 5 cm −1 . 
     
     
         6 . The process of  claim 1 , further comprising printing the film-forming composition onto the paper wrapper. 
     
     
         7 . The process of  claim 6 , further comprising printing the film-forming composition onto the paper wrapper in a multi-pass operation. 
     
     
         8 . The process of  claim 1 , further comprising applying the film-forming composition to the paper wrapper using gravure printing. 
     
     
         9 . The process of  claim 1 , further comprising drying the paper wrapper after the film-forming composition has been applied. 
     
     
         10 . The process of  claim 1 , further comprising incorporating the paper wrapper into a smoking article, the smoking article comprising a column of a smokable tobacco, the column of the smokable tobacco being surrounded by the paper wrapper. 
     
     
         11 . A paper wrapper having reduced ignition proclivity characteristics when incorporated into a smoking article, the paper wrapper comprising:
 a film-forming composition applied at particular locations in an amount from about 1% to about 15% by weight, the film-forming composition comprising a film-forming material comprising at least one of alginate, guar gum, pectin, polyvinyl alcohol, a cellulose derivative, starch, a starch derivative, or mixtures thereof, the film-forming material comprising a molecular weight such that the film-forming material has a viscosity of less than about 500 cP when present in a 3% by weight aqueous solution at 25° C., the film-forming composition forming treated discrete areas on the paper wrapper, the treated discrete areas being separated by untreated areas, the treated discrete areas having a BMI of less than 5 cm −1 , the treated areas having a permeability of less than about 40 Coresta, the untreated areas of the paper wrapper having a permeability of less than about 55 Coresta.   
     
     
         12 . The paper wrapper of  claim 11 , wherein the untreated areas of the paper wrapper have a permeability of less than about 30 Coresta. 
     
     
         13 . The paper wrapper of  claim 11 , wherein the untreated areas of the paper wrapper have a permeability ranging from about 15 Coresta to less than about 55 Coresta. 
     
     
         14 . The paper wrapper of  claim 11 , wherein the film-forming material is present in the composition such that the film-forming composition has a solids content of at least 6% by weight. 
     
     
         15 . The paper wrapper of  claim 11 , wherein the film-forming material has a viscosity of less than about 250 cP when present in a 3% by weight solution at 25° C. 
     
     
         16 . The paper wrapper of  claim 11 , wherein the alginate comprises a sodium alginate. 
     
     
         17 . The paper wrapper of  claim 11 , wherein the treated areas have a BMI of from about 1 cm −1  to about 5 cm −1 . 
     
     
         18 . The paper wrapper of  claim 11 , wherein the treated areas comprise a plurality of discrete circumferential bands disposed longitudinally along the paper wrapper, the bands having a width of greater than 4 mm, the bands being spaced from each other from a distance of from about 10 mm to about 40 mm. 
     
     
         19 . The paper wrapper of  claim 11 , further comprising incorporating the paper wrapper into a smoking article, the smoking article comprising a column of a smokable tobacco, the column of the smokable tobacco being surrounded by the paper wrapper. 
     
     
         20 . The paper wrapper of  claim 11 , wherein the film-forming composition comprises an aqueous composition.