Cigarette Paper with Improved Air-Permeability

Abstract

A cigarette paper is shown which has a surface, at least a part of the surface having the properties of: no artificial perforation an air permeability of at least 15 CU, and for an exponent k measured with a measuring head with a rectangular opening of 2 mm by 15 mm in accordance with ISO 2965:2009, which is defined as: k = log  Q 1 Q 2 log  p 1 p 2 where: Q 1 represents air-flow through the paper at a pressure difference p 1 =1.00 kPa, Q 2 represents air-flow through the paper at a pressure difference p 2 =0.25 kPa, and wherein k≦0.98 and k≧0.8.

1 . A cigarette paper having a surface, at least a part of the surface having the following properties:
 no artificial perforation   an air permeability of at least 15 CU, and   for an exponent k measured with a measuring head with a rectangular opening of 2 mm by 15 mm in accordance with ISO 2965:2009, which is defined as:   
       
         
           
             
               k 
               = 
               
                 
                   log 
                    
                   
                     
                       Q 
                       1 
                     
                     
                       Q 
                       2 
                     
                   
                 
                 
                   log 
                    
                   
                     
                       p 
                       1 
                     
                     
                       p 
                       2 
                     
                   
                 
               
             
           
         
         where: 
         Q 1  represents air-flow through the paper at a pressure difference p 1 =1.00 kPa, 
         Q 2  represents air-flow through the paper at a pressure difference p 2 =0.25 kPa, and wherein k≦0.98 and k≧0.8. 
       
     
     
         2 . The cigarette paper according to  claim 1 , wherein the air permeability is at least 20 CU. 
     
     
         3 . The cigarette paper according to  claim 1 , wherein the air permeability is at least 25 CU. 
     
     
         4 . The cigarette paper according to  claim 1 , wherein k≦0.95. 
     
     
         5 . The cigarette paper according to  claim 1 , wherein k≦0.93. 
     
     
         6 . The cigarette paper according to  claim 1 , wherein k≧0.85. 
     
     
         7 . The cigarette paper according to  claim 1 , wherein said part of the surface is at least 30% of total surface area. 
     
     
         8 . The cigarette paper according to  claim 7 , wherein said part of the surface is at least 50% of total surface area. 
     
     
         9 . The cigarette paper according to  claim 7 , wherein said part of the surface is at least 70% of total surface area. 
     
     
         10 . The cigarette paper according to  claim 1 , wherein said part of the surface is coated or treated with a material in an amount not exceeding 2.0 g/m 2 . 
     
     
         11 . The cigarette paper of  claim 10 , in which said material is a film-forming material. 
     
     
         12 . The cigarette paper of  claim 11 , wherein the amount of said film-forming material does not exceed 1.5 g/m 2 . 
     
     
         13 . The cigarette paper according to  claim 10 , wherein said material includes one or more of a starch, starch derivatives, especially oxidized starch, cellulose derivatives, especially carboxy methyl cellulose, guar, pectin or polyvinyl alcohol. 
     
     
         14 . The cigarette paper according to  claim 1 , wherein a basis weight is between 10 g/m 2  and 60 g/m 2 . 
     
     
         15 . The cigarette paper according to  claim 14 , wherein the basis weight is between 20 g/m 2  and 35 g/m 2 . 
     
     
         16 . The cigarette paper according to  claim 1 , wherein the paper further contains a filler material which is 10-45% by weight of the paper. 
     
     
         17 . The cigarette paper according to  claim 16 , wherein said filler material is formed by one or more of calcium carbonate, magnesium oxide or aluminum hydroxide. 
     
     
         18 . The cigarette paper according to  claim 16 , wherein the filler material is 20-45% by weight of the paper. 
     
     
         19 . The cigarette paper according to  claim 16 , wherein the filler material is 30-45% by weight of the paper. 
     
     
         20 . A cigarette paper according to  claim 1 , which further contains at least one burn additive made of one or more of the following salts: a citrate, especially tri-sodium or tri-potassium citrate, a malate, a tartrate, an acetate, a nitrate, a succinate, a fumarate, a gluconate, a glycolate, a lactate, an oxylate, a salicylate, a α-hydroxycaprylate and a phosphate. 
     
     
         21 . A cigarette with a tobacco rod wrapped by a cigarette paper according to  claim 1 . 
     
     
         22 . A method for producing a cigarette paper according to  claim 1 , with the following steps:
 producing a base paper,   treating at least a part of the surface of the base paper such that the exponent k, measured with a measuring head with a rectangular opening of 2 mm by 15 mm in accordance with ISO 2965:2009, which is defined by   
       
         
           
             
               k 
               = 
               
                 
                   log 
                    
                   
                     
                       Q 
                       1 
                     
                     
                       Q 
                       2 
                     
                   
                 
                 
                   log 
                    
                   
                     
                       p 
                       1 
                     
                     
                       p 
                       2 
                     
                   
                 
               
             
           
         
         is reduced such that k≦0.98 and k≧0.8, while maintaining an air permeability of at least 15 CU. 
       
     
     
         23 . The method according to  claim 22 , wherein the step of treating at least said part of the surface of the cigarette paper comprises the application of a material. 
     
     
         24 . The method according to  claim 23 , wherein the material is applied in the form of a solution or a colloidal suspension. 
     
     
         25 . The method according to  claim 23 , wherein the material is applied by printing, by spraying, or by application in a size press or film press of a paper machine. 
     
     
         26 . The method according to  claim 22 , wherein the step of treating at least said part of the surface of the cigarette paper comprises a step for embossing or compressing the paper. 
     
     
         27 . The method according to  claim 22 , wherein the step for treating at least said part of the surface of the cigarette paper is such that a ratio of large pores to small pores in the cigarette paper is increased.