| 摘要 |
PROBLEM TO BE SOLVED: To provide a copolymerized polyester suitable as a coating agent for an easily adhesive layer, which has low swelling property with an organic solvent to be used for a coating liquid of a functional layer such as a hard coat layer, which has excellent blocking resistance and easily adhesive property, and which hardly causes cracks in a coating layer in a stretching process even when the copolymerized polyester is applied by a generally employed in-line coating method.SOLUTION: A copolymerized polyester includes 60 to 80 mol% of a 2,6-naphthalene dicarboxylic acid component, 1 to 9 mol% of an aromatic dicarboxylic acid component having a sulfonate group, and 10 to 35 mol% of other aromatic carboxylic acid components, and includes 50 to 80 mol% of a specified glycol component expressed by formula (1), 10 to 30 mol% of an ethylene oxide adduct of bisphenol A, and 5 to 25 mol% of 9,9-bis[4,4-(2-hydroxyethoxy)phenyl]fluorene component. In the formula, Rrepresents a hydrogen atom or an alkyl group having 1 to 9 carbon atoms; Rrepresents an alkyl group having 2 to 9 carbon atoms; and n and m each represent an integer of 0 to 8, satisfying n+m ranging from 2 to 8. |
