| abstract |
(57) [Abstract] [Problem] Workability of coating film, corrosion resistance, adhesion, impact resistance, Provided is a one-coat coated steel sheet having excellent performance such as scratch resistance. (A) Glass transition temperature-25 to 35 ° C, number average molecular weight 1000 to 35,000 and hydroxyl value 3 Polyester resin 60 having 80 mg KOH / g 95 parts by weight and (B) 5 to 40 parts by weight of a melamine resin curing agent, which is either a methyl etherified melamine resin or a melamine resin mixture of a methyl etherified melamine resin and a butyl etherified melamine resin, and a total amount of these 100 A coating composition containing (C) 1 to 50 parts by weight of an anticorrosive pigment and (D) 2 to 40 parts by weight of organic polymer fine particles per part by weight, and zinc plating subjected to a chromate chemical conversion treatment. A one-coat coated steel sheet in which a cured coating film of this coating composition is formed on a steel sheet. |