Patent ID: 7749578

Claim:
A cellulose ester film comprising cellulose ester, polymer X having a weight average molecular weight of 2000-30000 prepared by copolymerizing ethylenic unsaturated monomer Xa containing no aromatic ring and no hydrophilic group within a molecule and ethylenic unsaturated monomer Xb containing no aromatic ring but a hydrophilic group within a molecule, and polymer Y having a weight average molecular weight of 500-3000 prepared by polymerizing ethylenic unsaturated monomer Ya containing no aromatic ring wherein the polymer X is expressed by following Formula (1), and the polymer Y is expressed by following Formula (2): —[CH 2 —C(—R 1 )(COOR 2 )] m -[CH 2 (—CR 3 )(COOR 4 —OH)-] n Formula (1) R y -[CH 2 —C(—R 5 )(COOR 6 )] k -OH Formula (2) where each of R 1 , R 3 and R 5 is H or CH 3 , each of R 2 and R 6 is CH 3 , C 2 H 5 or C 3 H 7 , R 4 is CH 2 , C 2 H 4 or C 3 H 6 , Ry is OH, H or alkyl having a carbon number of at most 3, and each of m, n and k is an integer.