| 摘要 |
PURPOSE:To enable formation of dense, uniform and strongly adhered black film on a shadow mask, by exposing a shadow mask plate of iron or ferrous alloy to the atmosphere to water vapor and thereby forming a blackened film chiefly of Fe3O4 on the surface. CONSTITUTION:By leaving a shadow mask plate of iron or ferrous alloy to be exposed to water vapor, a blackened film chiefly of Fe3O4 is formed on the surface of the shadow mask. If, then, the water vapor pressure is set at 0.5- 105kg/cm<2> and its temperature is set at 100-900 deg.C, even the ferrous alloy can well absorb oxtgen and a good blackened film chiefly of Fe3O4 is formed. |
