Colored steel sheet with single side embossed

摘要

PURPOSE: A colored steel sheet with single side embossed is provided which obtains three-dimensional beautiful external appearance, solves problems of environmental regulation and shortens processing process using the steel sheet with single side embossed as a material processed, and a manufacturing method of the same is provided. CONSTITUTION: In a colored steel sheet with single side embossed in which a chromate layer is formed on a base steel sheet with single side embossed, a polyester based primer having high forming workability is formed on the chromate layer, and a resin composition comprising a principal resin of polyester resin, a crosslinking agent of melamine resin, curing promoter, other additives and solvent is coated on the polyester based primer as a top coat, the colored steel sheet with single side embossed is characterized in that the polyester resin is a modified oil free polyester compound prepared by reacting oil free polyester having number average molecular weight of 10000 to 30000, glass transition temperature (Tg) of -5 to 45 deg.C and OH value of 40 to 90 with ordinary non-yellowish type polyisocyanate, wherein the top coat composing the top coating layer essentially comprises 0.5 to 3 weight parts of organic filler for the top coat, the organic filler is polyamide, and the top coat composing the top coating layer comprises 0.1 to 3.0 weight parts of pure amine, preferably secondary amine for the top coat for promoting crosslinking between the polyester resin and the melamine resin and forming creases so that curing speed difference between inner and outer parts of the coating layer is generated during baking process of the top coating layer, thereby forming three-dimensional irregularities on the surface of the top coating layer.