| 摘要 |
PROBLEM TO BE SOLVED: To obtain an optical element having extremely small optical anisotropy, excellent in transparency, mechanical characteristics, electrical characteristics, moldability and dimensional stability and useful for disk substrates, or the like, by molding a specific polyester polymer. SOLUTION: This optical element is obtained by molding a polyester polymer composed of (A) a dicarboxylic acid (an ester-forming derivative) containing preferably 50-100 mol% (based on total dicarboxylic component) one or more alicyclic dicarboxlic acids selected from cyclohexanedicarboxylic acid, decalin dicarboxylic acid, norbornane dicarboxylic acid, adamantane dicarboxylic acid and tricyclodecene dicarboxylic acid and (B) a dihydroxy compound containing a compound of the formula (R1 is a 2-4C alkylene; R2 to R5 are each H, a 1-4C alkyl, aryl or aralkyl) such as 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene, preferably in an amount of 10-95 mol% based on a glycol component in the resin.
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