Polyester resin, resin composition for can coating, painted metal plate for can and can

摘要

This invention provides a polyester resin that is capable of forming a coating film having extremely excellent curability, processability, retort resistance, content resistance, and dent resistance, and also provides a resin composition for a coating composition containing the polyester resin. The polyester resin obtained from a polycarboxylic acid component and a polyol component, wherein the polyester resin meets the conditions (i) to (iii) described below: (i) among the polycarboxylic acid components constituting the polyester resin, the total copolymerization ratio of terephthalic acid component and 2,6-naphthalenedicarboxylic acid component is 80 mol% or more; (ii) among the polycarboxylic acid components constituting the polyester resin, the copolymerization ratio of 2,6-naphthalenedicarboxylic acid component is 2 to 80 mol%; and (iii) among the polyol components constituting the polyester resin, the total copolymerization ratio of ethylene glycol component and 1,2-propylene-glycol component is 50 mol% or more, wherein the copolymerization ratio of 1,2-propylene-glycol component is excessive relative to the copolymerization ratio of the ethylene glycol component.