Polyester resin

1 . A polyester resin comprising:

dicarboxylic acid constituent units and diol constituent units,

wherein the diol constituent units comprise a constituent unit A 1 derived from a diol having a cyclic acetal skeleton, and a constituent unit A 2 derived from 2,2,4,4-tetramethoxy-1,3-cyclobutanediol, and

wherein the dicarboxylic acid constituent units comprise a constituent unit B 1 derived from 2,6-naphthalenedicarboxylic acid and/or dimethyl 2,6-naphthalenedicarboxylate.

2 . The polyester resin according to claim 1 , wherein the diol constituent units further comprise a constituent unit A 3 derived from ethylene glycol.

3 . The polyester resin according to claim 1 , wherein the diol having a cyclic acetal skeleton comprises at least one selected from the group consisting of compounds represented by the following formula (1) and formula (2):

wherein R 1 and R 2 each independently represent a divalent aliphatic group having 1 to 10 carbon atoms, a divalent alicyclic group having 3 to 10 carbon atoms, or a divalent aromatic group having 6 to 10 carbon atoms,

wherein R 1 represents a divalent aliphatic group having 1 to 10 carbon atoms, a divalent alicyclic group having 3 to 10 carbon atoms, or a divalent aromatic group having 6 to 10 carbon atoms, and R 3 represents a monovalent aliphatic group having 1 to 10 carbon atoms, a monovalent alicyclic group having 3 to 10 carbon atoms, or a monovalent aromatic group having 6 to 10 carbon atoms.

4 . The polyester resin according to claim 1 , wherein the diol having a cyclic acetal skeleton comprises 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane.