| 摘要 |
PROBLEM TO BE SOLVED: To obtain a polyethylene naphthalate copolymer that can form biaxially oriented film excellent in resistance to delamination, mechanical strength, in addition, high resistance to curling, excellent is hue and transparency, particularly can form a biaxially oriented film for photography and prepare the film therefrom. SOLUTION: The objective polyethylene naphthalate copolymer includes naphthalenedicarboxylic acid as main carboxylic acid component, etylene glycol as main glycol component, and, as copolymerization components, (1) 0.5-10 mol.% (based on the whole amounts of the dicarboxylic acid components and P-hydroxyethoxybenzoic acid component) of p-hydroxy-ethoxybenzoic acid, and (2) <=3 mol.% of diethylene glycol based on the total amount of the whole glycol components. |
