Method for producing cellulose derivative, and cellulose derivative

Abstract

A method for producing a cellulose derivative, including reacting a mixed acid anhydride having two particular types of acyl groups with cellulose in the presence of a base catalyst in an organic solvent having an electron pair-donating property to form a cellulose derivative with the two types of acyl groups derived from the mixed acid anhydride, the acyl groups being introduced at hydroxy groups in the cellulose.

What is claimed is: 
     
         1 . A method for producing a cellulose derivative, comprising reacting a mixed acid anhydride represented by the following chemical formula (A): 
       
         
           
           
               
               
           
         
       
       wherein R SH  represents an organic group having 1 to 3 carbon atom(s); and R LO  represents an organic group having an electron-withdrawing property, with cellulose in the presence of a base catalyst in an organic solvent having an electron pair-donating property to form a cellulose derivative with a first acyl group (—COR SH ) and a second acyl group (—COR LO ) introduced at hydroxy groups in the cellulose. 
     
     
         2 . The method for producing a cellulose derivative according to  claim 1 , wherein, in the chemical formula (A), R LO  represents an organic group having a higher electron-withdrawing property than that of R SH . 
     
     
         3 . The method for producing a cellulose derivative according to  claim 1 , wherein the reaction is performed further in the presence of an acid anhydride represented by (R SH CO) 2 O. 
     
     
         4 . The method for producing a cellulose derivative according to  claim 1 , wherein the organic solvent has a donner number (Dn) of 10 or more. 
     
     
         5 . The method for producing a cellulose derivative according to  claim 1 , wherein, in the chemical formula (A), R SH  is a group selected from the group consisting of a methyl group, an ethyl group, a propyl group and an isopropyl group. 
     
     
         6 . The method for producing a cellulose derivative according to  claim 1 , wherein, in the chemical formula (A), R SH  is a methyl group. 
     
     
         7 . The method for producing a cellulose derivative according to  claim 1 , wherein, in the chemical formula (A), R LO  is:
 a group comprising at least one divalent group selected from the group consisting of an ether group (—O—), an ester group (—O—CO—), an amide group (—NH—CO—), a urethane group (—NH—CO—O—) and a carbonate group (—O—CO—O—); a first organic group bonding to the carbonyl carbon in the mixed acid anhydride; and a second organic group linked to the first organic group through the divalent group; or   an aryl group.   
     
     
         8 . The method for producing a cellulose derivative according to  claim 1 , wherein, in the chemical formula (A), R LO  is a group comprising at least one divalent group being an ether group (—O—); a first organic group bonding to the carbonyl carbon in the mixed acid anhydride; and a second organic group linked to the first organic group through the divalent group (—O—). 
     
     
         9 . The method for producing a cellulose derivative according to  claim 7 , wherein, the divalent group is bonding to a carbon atom in the first organic group, the carbon atom bonding to the carbonyl carbon in the mixed acid anhydride. 
     
     
         10 . The method for producing a cellulose derivative according to  claim 7 , wherein the first organic group is a methylene group. 
     
     
         11 . The method for producing a cellulose derivative according to  claim 7 , wherein the second organic group is a hydrocarbon group having 1 to 24 carbon atom(s). 
     
     
         12 . The method for producing a cellulose derivative according to  claim 1 , wherein, in the chemical formula (A), R LO  is a hydrogenated cardanoxymethyl group represented by —CH 2 —O—C 6 H 4 —(CH 2 ) 14 CH 3  or —CH 2 —O—C 6 H 10 —(CH 2 ) 14 CH 3 . 
     
     
         13 . The method for producing a cellulose derivative according to  claim 1 , wherein the base catalyst is a nitrogen-containing basic organic compound having a tertiary amine structure. 
     
     
         14 . The method for producing a cellulose derivative according to  claim 1 , wherein the base catalyst is at least one basic compound selected from the group consisting of an amine-based compound, a pyridine-based compound, an imidazole-based compound and an amidine-based compound. 
     
     
         15 . The method for producing a cellulose derivative according to  claim 1 , wherein
 a degree of substitution with the second acyl group (—COR LO ) is 0.1 or more; and   a total degree of substitution with the first acyl group (—COR SH ) and the second acyl group (—COR LO )(DS SH +DS LO ) is 2 or more.   
     
     
         16 . The method for producing a cellulose derivative according to  claim 1 , comprising performing an activation treatment before the reaction is performed, wherein the activation treatment comprises a step of soaking the cellulose in an activation solvent. 
     
     
         17 . The method for producing a cellulose derivative according to  claim 16 , wherein acetic acid or dimethylsulfoxide is used as the activation solvent. 
     
     
         18 . A cellulose derivative produced by the method for production according to  claim 1 . 
     
     
         19 . A cellulose derivative with a first acyl group and a second acyl group introduced at at least some of hydroxy groups contained in cellulose, wherein
 the first acyl group is an acyl group having 2 to 4 carbon atoms; and   the second acyl group is an acyl group represented by the following chemical formula (B):
   —CO—CH 2 —OR  (B)
 
   
       wherein —OR represents an organic group having 1 to 24 carbon atom(s) other than a cardanoxy group. 
     
     
         20 . The cellulose derivative according to  claim 19 , wherein, in the chemical formula (B), R is an aliphatic hydrocarbon group having 1 to 24 carbon atom(s). 
     
     
         21 . The cellulose derivative according to  claim 19 , wherein the first acyl group is an acetyl group or a propionyl group. 
     
     
         22 . The cellulose derivative according to  claim 19 , wherein
 a degree of substitution with the second acyl group (DS LO ) is 0.1 or more; and   a total degree of substitution with the first acyl group and the second acyl group (DS SH +DS LO ) is 2 or more.   
     
     
         23 . A cellulose-based resin composition comprising the cellulose derivative according to  claim 18  as a base resin. 
     
     
         24 . A molded object obtained by molding the cellulose-based resin composition according to  claim 23 .