Polyester resin, resin composition for paint cans, painted metal plate for cans, and cans

摘要

Polyester resin obtained from a polycarboxylic acid component and a polyol component, in which the polyester resin meets the conditions (i) to (iii) described below: (i) between the polycarboxylic acid components that constitute the polyester resin, the total copolymerization ratio of the terephthalic acid component and the 2,6-naphthalenedicarboxylic acid component is 80 mol% or more; (ii) among the polycarboxylic acid components that constitute the polyester resin, the copolymerization ratio of the 2,6-naphthalenedicarboxylic acid component is from 2 to 70 mol%; and (iii) between the polyol components constituting the polyester resin, the total copolymerization ratio of the ethylene glycol component and the 1,2-propylene glycol component is 50 mol% or greater, in which the copolymerization ratio of the 1,2-propylene glycol component is excessive with respect to the copolymerization ratio of the ethylene glycol component, in which the lower limit of the copolymerization ratio of the ethylene glycol constituting the polyester resin, with respect to the total polyol components , is 5% in moles.