| abstract |
PROBLEM TO BE SOLVED: To provide a method for producing a cyclic ester-modified cellulose derivative having excellent heat stability and improved coloring. SOLUTION: Based on 100 parts by weight of a cellulose derivative such as a hydroxyl group-containing cellulose acetate, 0.05 to 1.0 part by weight of a phosphite compound and 0.001 part of a weak organic acid. To 0.5 part by weight, thioether compound 0.05 to 1. 0 parts by weight are blended and modified with a cyclic ester such as ε-caprolactone. |