| 摘要 |
PURPOSE:To prevent luminous picture elements from missing, by preparing an aqueous solution containing a polyvinyl alcohol of prescribed polymerization degree and having a prescribed pH level, as a pre-coating liquid in a pre-coating process for forming a phosphor screen of a color cathode-ray tube. CONSTITUTION:When a phosphor screen of a color cathode-ray tube is formed, the inside surface of a glass panel is first washed and a pre-coating liquid, which is an aqueous solution containing 0.01-0.1wt% of a polyvinyl alcohol of 3,100-3,800 in polymerization degree and is set at a pH level of 2.0-4.0 is then applied to the inside surface. A phosphor material slurry film is then made on the inside surface and subjected to drying, exposure and development process to make prescribed luminous picture elements. The thickness of the film of the applied pre-coating liquid is made very small. The adhesive power of the pre-coating liquid film is enhanced by hydroxyl groups based on the polyvinyl alcohol of high polymerization degree. As a result, missing of the luminous picture elements is prevented without diminishing the luminance of the phosphor screen.
|
