Alkylene oxide modified hardwood cellulose

Abstract

Disclosed is a process for producing reactive cellulose for use in the manufacture of cellulose acetate having superior clarity by mercerizing hardwood cellulosic material and reacting it with an hydroxyalkylating agent to a degree of molar substitution ranging from 0.04 to 0.15 per anhydroglucose unit in cellulose.

What is claimed is:  
     
         1 . A process for the preparation of cellulose acetate comprising: 
 mercerizing cellulosic material derived from hardwood in a caustic mercerizing solution to produce mercerized hardwood cellulose;    reacting the mercerized hardwood cellulose with an alkylene oxide hydroxyalkylating agent to a degree of substitution of the cellulose ranging from 0.04 to 0.15 to form a reactive mercerized hardwood cellulose, said degree of substitution being insufficient to render said mercerized hardwood cellulose appreciably soluble in water;    recovering said reactive substantially water insoluble mercerized hardwood cellulose and acetylating it to form cellulose acetate.    
     
     
         2 . The process of  claim 1  in which the cellulosic material derived from hardwood is mercerized with a caustic solution of about 8 to 20 weight percent.  
     
     
         3 . The process of  claim 2  in which the caustic solution is about 10 to 16 weight percent.  
     
     
         4 . The process of  claim 2  in which the reacting of the mercerized hardwood cellulose with an alkylene oxide is carried out in the presence of a caustic solution of the same concentration as the mercerizing solution.  
     
     
         5 . The process of  claim 1  in which the cellulosic material is hardwood cellulosic pulp.  
     
     
         6 . The process of  claim 1  in which the degree of alkylene oxide substitution of the cellulose is from 0.05 to 0.09 moles of alkylene oxide per anhydroglucose unit in said cellulose material.  
     
     
         7 . The process of  claim 1  in which the hydroxyalkylating agent is propylene oxide and the degree of substitution of propylene oxide per anhydroglucose unit is from 0.06 to 0.08.