Wrapping materials for smoking articles

Abstract

Smokable rods of cigarettes are manufactured using wrapping materials that incorporate at least one fibrous material (e.g., flax fibers, hardwood pulp fibers and/or softwood pulp fibers) at least one filler material (e.g., calcium carbonate in particulate form). The wrapping materials possess multi-layer coatings. The wrapping materials possess coatings in the form of series of spaced apart bands, each band possessing a series of layers. At least one of the coating layers can have a filler material dispersed or suspended within a film-forming material of that layer.

1 . A wrapping material for a smoking article, the wrapping material adapted to be wound on a roll, the wrapping material comprising: 
 a smoking article wrapping material substrate; and    at least two coatings deposited in a pattern on the substrate, the at least two coatings comprising a non-aqueous first coating being deposited directly onto the wrapping material substrate and being effective to reduce the water absorption of the substrate, and a water-based second coating deposited on the first coating, the second coating being effective to cause a reduction in inherent porosity of the substrate.    
     
     
         2 . The wrapping material of  claim 1 , wherein the first coating comprises a film-forming material.  
     
     
         3 . The wrapping material of  claim 2 , wherein the film-forming material is selected from the group consisting of ethylcellulose, polyvinyl acetate, nitrocellulose, cellulose acetate propionate, ethylene vinylacetate, and any combination thereof.  
     
     
         4 . The wrapping material of  claim 1 , wherein the water-based second coating comprises material selected from the group consisting of polyvinyl alcohol, ethylene vinylacetate, starch, sodium citrate dihydrate, potassium citrate monohydrate, and diammonium phosphate.  
     
     
         5 . The wrapping material of  claim 1 , further comprising a third coating overlying the second coating, the third coating being effective in preventing blocking when the wrapping material is unwound from a roll.  
     
     
         6 . The wrapping material of  claim 5 , wherein the first and third coatings each include ethylcellulose and the second coating includes ethylene vinylacetate.  
     
     
         7 . The wrapping material of  claim 1 , wherein at least one of the first coating and the second coating comprises a filler.  
     
     
         8 . The wrapping material of  claim 7 , wherein the filler is selected from the group consisting of calcium carbonate, calcium phosphate, clay, talc, aluminum oxide, mica, magnesium oxide, calcium sulfate, magnesium carbonate, magnesium hydroxide, aluminum oxide, titanium dioxide, starch, flour, particulate polyvinyl alcohol, particulate tobacco, fibrous cellulose, graphite, carbon fiber, ceramic, and particulate iron.  
     
     
         9 . The wrapping material of  claim 7 , wherein the first coating comprises a filler that is a water-soluble salt.  
     
     
         10 . The wrapping material of  claim 9 , wherein the water-soluble salt is an alkali metal chloride or a citrate salt.  
     
     
         11 . The wrapping material of  claim 9 , wherein the water-soluble salt is selected from the group consisting of sodium chloride, potassium chloride, sodium citrate, potassium citrate, sodium citrate dihydrate, and potassium citrate monohydrate.  
     
     
         12 . The wrapping material of  claim 7 , wherein the filler is particulate and the diameter of the filler particles is less than about 3 microns.  
     
     
         13 . The wrapping material of  claim 7 , wherein the filler is particulate and the diameter of the filler particles is between about 0.3 and 2 microns.  
     
     
         14 . The wrapping material of  claim 1 , wherein the water-based second coating comprises an adhesive.  
     
     
         15 . The wrapping material of  claim 14 , wherein the adhesive comprises an ethylene vinyl acetate copolymer emulsion.  
     
     
         16 . The wrapping material of  claim 1 , wherein at least one of the at least two coatings comprises an optical brightener.  
     
     
         17 . The wrapping material of  claim 1 , wherein the pattern on the substrate comprises a plurality of spaced apart bands.  
     
     
         18 . The wrapping material of  claim 17 , wherein the width of each of the plurality of spaced apart bands is about 0.5 mm to about 8 mm.  
     
     
         19 . The wrapping material of  claim 17 , wherein the width of each of the plurality of spaced apart bands is about 4 mm to about 7 mm.  
     
     
         20 . The wrapping material of  claim 17 , wherein at least one of the plurality of spaced apart bands is a continuous band.  
     
     
         21 . The wrapping material of  claim 17 , wherein at least one of the plurality of spaced apart bands is a discontinuous band.  
     
     
         22 . The wrapping material of  claim 1 , further comprising an overcoat layer applied over the substrate and the at least two coatings.  
     
     
         23 . The wrapping material of  claim 22 , wherein the overcoat layer comprises a salt.  
     
     
         24 . The wrapping material of  claim 1 , wherein the porosity in a region covered by the at least two coatings is about 3 to about 5.2 CORESTA units.  
     
     
         25 . A smoking article comprising a rod of smokable material in a tube of the wrapping material of  claim 1 .  
     
     
         26 . The smoking article of  claim 25 , wherein the coating is disposed on the inside of the tube.