Luminescent screen prodn in colour television tubes - using a stabiliser in the suspension of luminescent material and binder

摘要

Light-sensitive suspension for the mfr. of luminescent screens for cathodle-ray tubes, contains a luminescent material and a binder such as polyvinyl alcohol or gelatin sensitized by a chromium cpd. The suspension also contains, as a stabiliser, an addn. of alkali fluoride and/or ammonium fluoride and/or ammonium carbonate and/or ammonium bicarbonate. Based on the dry substances in the suspension, pref. 0.001-10 wt. % and esp. 0.01-0.1 wt. % of the stabiliser is employed, and the suspension may be weakly acid, neutral or alkaline; the exposure time used to harden the layer on the cathode ray tube is pref. reduced. When the stabiliser is added to suspension sensitised with ammonium bichromate, they can be used even after long storage times irrespective of whether they are weakly acid, neutral or alkaline.