| 摘要 |
PROBLEM TO BE SOLVED: To obtain an excellent adhesion property between layers by applying a specified overcoat base coating material and a specified overcoat clear coating material in a wet-on-wet process and baking. SOLUTION: An overcoat clear coating material is applied and baked on a primer hardened coating film on a long-length metal sheet to form an overcoat clear coating film on the overcoat color base coating film. The film forming resin component of the overcoat color base coating material consists of 60 to 95 pts.wt. hydroxyl group-contg. polyester resin and 5 to 40 pts.wt. crosslinking agent such as melamine resin. The film forming resin component of the overcoat clear coating material consists of 55 to 90 pts.wt. hydroxyl group-contg. org. resin having -20 to 80 deg.C glass transition temp. and 10 to 45 pts.wt. crosslinking agent such as melamine resin. The overcoat clear coating material contains 1 to 20 pts.wt. org. resin powder comprising org. resin particles of 5 to 80μm average particle size or particles having 2 to 50μm average diameter, 30 to 5000μm length and 1/2 to 1/100 diameter to length ratio to 100 pts.wt. of the film forming resin component. The hardened coating film formed has 150 to 700 mol.wt. of inter crosslink molecules. |
