Biodegradable composites

Abstract

The present invention concerns a biodegradable cigarette filter tow comprising composite filaments of cellulose and cellulose acetate, wherein the composite filaments are entangled or wherein the two further comprises one or more further thermoplastic materials or wherein the weight ration of cellulose to cellulose acetate in the tow is from 10:90 to 90:10, and a process for making such a filter tow comprising providing a solution dope comprising a blend of cellulose and cellulose acetate in an ionic liquid or in N-methylmorphilone-N-oxide (NMMO), and spinning casting the blend into a protic solvent to generate fibres or films, and converting the fibres or films into cigarette filter tow. The invention also concerns cigarette filters and cigarettes made from such a filter tow.

1 . A biodegradable cigarette filter tow comprising composite filaments of cellulose and cellulose acetate, and further comprising one or more further thermoplastic materials. 
     
     
         2 . The filter tow according to  claim 1 , wherein the further thermoplastic material is selected from one or more of PHB, PHVB, polyacrylonitrile (PAN), poly-2-hydroxyethylmethylacrylate (PHEMA), polyvinylalcohol (PVA), polyaniline and polyethylene glycol. 
     
     
         3 . A biodegradable cigarette filter tow, comprising:
 composite filaments of cellulose and cellulose acetate,   wherein the weight ratio of cellulose to cellulose acetate is from 10:90 to 90:10.   
     
     
         4 . The filter tow according to  claim 3 , wherein the ratio of cellulose to cellulose acetate is from 20:80 to 80:20. 
     
     
         5 . The filter tow according to  claim 4 , wherein the ratio of cellulose to cellulose acetate is from 30:70 to 70:30. 
     
     
         6 . A biodegradable cigarette filter tow, comprising entangled composite filaments of cellulose and cellulose acetate. 
     
     
         7 . The filter tow according to  claim 1 , further comprising one or more plasticisers. 
     
     
         8 . The filter tow according to  claim 1 , further comprising a catalyst promoting oxidative degradation of the filter tow. 
     
     
         9 . The filter tow according to  claim 1 , further comprising one or more lubricants to reduce electrostatic charge on the tow. 
     
     
         10 . A cigarette filter, comprising the cigarette filter tow according to  claim 1  encased in a tipping wrapper. 
     
     
         11 . A cigarette, comprising a smokable substance and the cigarette filter according to  claim 10 . 
     
     
         12 . A process for manufacturing the cigarette filter tow according to  claim 1 , comprising:
 providing a solution dope comprising a blend of cellulose and cellulose acetate in an ionic liquid or in N-methylmorphilone-N-oxide (NMMO);   spinning or casting the blend into a protic solvent to generate fibres or films, and   converting the fibres or films into the cigarette filter tow.   
     
     
         13 . The process according to  claim 12 , wherein the dope further comprises an aprotic solvent to aid dissolution of the cellulose and/or cellulose acetate. 
     
     
         14 . The process according to  claim 13 , wherein the aprotic solvent comprises one or more of DMSO, DMF, THF or dioxane. 
     
     
         15 . The filter tow according to  claim 3 , further comprising one or more plasticisers. 
     
     
         16 . The filter tow according to  claim 6 , further comprising one or more plasticisers. 
     
     
         17 . The filter tow according to  claim 3 , further comprising a catalyst promoting oxidative degradation of the filter tow. 
     
     
         18 . The filter tow according to  claim 6 , further comprising a catalyst promoting oxidative degradation of the filter tow. 
     
     
         19 . The filter tow according to  claim 3 , further comprising one or more lubricants to reduce electrostatic charge on the tow. 
     
     
         20 . The filter tow according to  claim 6 , further comprising one or more lubricants to reduce electrostatic charge on the tow. 
     
     
         21 . A cigarette filter, comprising the cigarette filter tow according to  claim 3  encased in a tipping wrapper. 
     
     
         22 . A cigarette filter, comprising the cigarette filter tow according to  claim 6  encased in a tipping wrapper. 
     
     
         23 . A process for manufacturing the cigarette filter tow according to  claim 3 , comprising:
 providing a solution dope comprising a blend of cellulose and cellulose acetate in an ionic liquid or in N-methylmorphilone-N-oxide (NMMO);   spinning or casting the blend into a protic solvent to generate fibres or films; and   converting the fibres or films into the cigarette filter tow.   
     
     
         24 . A process for manufacturing the cigarette filter tow according to  claim 6 , comprising:
 providing a solution dope comprising a blend of cellulose and cellulose acetate in an ionic liquid or in N-methylmorphilone-N-oxide (NMMO);   spinning or casting the blend into a protic solvent to generate fibres or films; and   converting the fibres or films into the cigarette filter tow.