| 摘要 |
PROBLEM TO BE SOLVED: To provide a process for producing a surface treated steel sheet which is formed with the films having a structure to prevent the direct contact of resins with metal molds by the lubricant layers on the surfaces, to be replenished with lubricants from the inside of the films at all times in spite of the drastic deformation of the films in deep drawing, etc., by the particles to be dispersed into the films and to maintain good lubricative workability and has the excellent press working characteristic to allow film forming in high-speed passage by high-temp. short-time baking. SOLUTION: An aq. lubricative coating material contg. 10 to 40% silica, 3 to 30% polyolefin wax and 2 to 10% high boiling point solvent in an ester type urethane resin and epoxy resin is applied on the surfaces of the plated steel sheet subjected to a chemical conversion treatment. Thereafter, the coating is formed to 0.3 to 5μm lubricative film thickness for baking time of 2 to 8 second stepped heating by combination use of induction heating at <=300 deg.C in-furnace atmosphere temp. and hot air furnace heating. In addition, surface lubricant coating layers are formed on the lubricative layers at 0.04 to 1μm thickness.
|
