Tobacco smoke filter material and process for the preparation thereof

Abstract

Disclosed are materials and compositions effective for the selective removal of gaseous aldehydes from tobacco smoke. The materials and compositions comprise tobacco smoke filters comprising a fibrous material or fibers of a polymeric material containing covalently-bonded acetoacetoxy residues. The fibrous material or fibers are capable of reacting with and removing aldehydes present in tobacco smoke. Also disclosed are processes for the preparation of fibrous materials and fibers of a polymeric material containing covalently-bonded acetoacetoxy residues and methods for the removal of a gaseous aldehyde from tobacco smoke by contacting tobacco smoke with the aforesaid fibrous materials or fibers containing covalently-bonded acetoacetoxy residues.

1 . A fibrous filter element comprising fibers of a polymeric material wherein the polymeric material contains covalently bonded acetoacetyl residues. 
   
   
       2 . The fibrous filter element of  claim 1  wherein the polymeric material is cellulose acetate having an acetyl degree of substitution of about 1.2 to 2.8. 
   
   
       3 . The fibrous filter element of  claim 2  wherein the filter element is a tobacco smoke filter comprising 2,000 to 30,000 cellulose acetate filaments having a denier per filament of about 2 to 8 and a total denier of about 15,000 to 50,000 and the cellulose acetate contains covalently bonded acetoacetyl residues 
   
   
       4 . A method of removing a gaseous aldehyde from tobacco smoke by contacting tobacco smoke containing one or more aldehydes with a fibrous filter element comprising fibers of a polymeric material wherein the polymeric material contains covalently bonded acetoacetyl residues. 
   
   
       5 . A method according to  claim 4  wherein the polymeric material is cellulose acetate having an acetyl degree of substitution of about 1.2 to 2.8. 
   
   
       6 . A method according to  claim 4  wherein the filter element is a tobacco smoke filter comprising 2,000 to 30,000 cellulose acetate filaments having a denier per filament of about 2 to 8 and a total denier of about 15,000 to 50,000 and the cellulose acetate contains covalently bonded acetoacetyl residues 
   
   
       7 . A smoking article comprised of a first section comprising burnable tobacco and a second filter plug section comprising fibers of a polymeric material wherein the polymeric material contains covalently bonded acetoacetyl residues. 
   
   
       8 . A smoking article according to  claim 7  wherein the polymeric material is cellulose acetate having an acetyl degree of substitution of about 1.2 to 2.8. 
   
   
       9 . A smoking article according to  claim 7  wherein the filter plug comprises 2,000 to 30,000 cellulose acetate filaments having a denier per filament of about 2 to 8 and a total denier of about 15,000 to 50,000 and the cellulose acetate contains covalently bonded acetoacetyl residues. 
   
   
       10 . A method for the preparation of a fibrous filter element comprising fibers of a polymeric material wherein the polymeric material contains covalently bonded acetoacetyl residues which comprises contacting a fibrous material constructed of or comprising a reactant polymer containing hydroxyl groups with gaseous diketene. 
   
   
       11 . A method according to  claim 10  wherein a fibrous filter element comprising fibers of cellulose acetate having an acetyl degree of substitution of about 1.2 to 2.8 is contacted with gaseous diketene at a temperature of about 25 to 120° C. 
   
   
       12 . A method according to  claim 10  wherein a fibrous filter element comprising fibers of cellulose acetate having an acetyl degree of substitution of about 1.8 to 2.5 is contacted with gaseous diketene at a temperature of about 40 to 100° C. in the presence of a catalytic amount of a tertiary amine. 
   
   
       13 . A method according to  claim 11  wherein the fibrous material is a tobacco smoke filter element comprising 2,000 to 30,000 cellulose acetate filaments having a denier per filament of about 2 to 8 and a total denier of about 15,000 to 50,000 and the cellulose acetate contains covalently bonded acetoacetyl residues. 
   
   
       14 . A method according to  claim 11  wherein a tobacco smoke filter element comprising 2,000 to 30,000 cellulose acetate filaments having a denier per filament of about 2 to 8 and a total denier of about 15,000 to 50,000 is contacted with gaseous diketene at a temperature of about 40 to 100° C. in the presence of a catalytic amount of a tertiary amine, wherein the cellulose acetate has an acetyl degree of substitution of about 1.8 to 2.5.