FUNNEL GLASS FOR CATHODE-RAY TUBE AND ITS MANUFACTURING AND CLEANING METHODS

摘要

PROBLEM TO BE SOLVED: To provide a funnel glass for a cathode-ray tube and its manufacturing and cleaning methods since coating and formation of a uniform and thick soluble protection film on the funnel glass surface serve in efficiently preventing damage to, and contamination of, the glass itself, being able to store it for a long period without easy erosion of the glass surface and being able to wash with water and easily remove the protection film without concern over the safety of organism and environment because of its high biodegradability. SOLUTION: The funnel glass for a cathode-ray tube is provided with an anode button sealed therein and with its part or whole of the surface coated and formed containing with soluble protection film a hydroxy acid or salt.