| abstract |
The present invention addresses the problem of providing: a polyester composition capable of more easily providing a polyester film having excellent dimensional stability, in particular, excellent dimensional stability against environmental changes such as humidity changes; and a polyester film and a magnetic recording medium using the polyester composition. The present invention pertains to a polyester composition which has a main repeating unit composed of an aromatic dicarboxylic acid component (component A) and an ethylene glycol component (component C), and contains a long-chain alkyl dicarboxylic acid component (component B) having 6 or more carbon atoms or a long-chain alkyl diol component (component D) having 6 or more carbon atoms, wherein the sum (WB+WD) of the percentage (WB) of component B with respect to the total number of moles of component A and component B and the percentage (WD) of component D with respect to the total number of moles of component C and component D is in the range of 2-13 mol%. |