A method for the production of led's fabric grids for fluorescent screens of cathodes beam bending and, in this case, for suitable layer compositions

摘要

1,135,656. Photo-sensitive materials. NATIONAL VIDEO CORP. Aug. 8, 1966 [Sept.22, 1965], No. 35429/66. Heading G2C. [Also in Division H1] In a method of manufacturing a phosphor array for a cathode ray tube screen in which at least one phosphor-containing photo-sensitive coating composition is applied to the screen, exposed to active light to harden selected areas and then developed to remove the coating from unexposed areas, a water soluble mono- or di-cyclic ether which acts as a surface-active and dispersing agent is incorporated in the photo-sensitive coating in an amount comprising at least 0À05% by weight. The cyclic ether, which may be 1,4-dioxane, tetrahydrofuran, or tetrahydropyran comprising 0À05 to 3À0% by weight, reduces the exposure and drying time and inhibits cross-contaminators between individual phosphor elements. In an example the cyclic ether was added to the blue and red phosphorcontaining compositions which were applied in turn over a green phosphor-containing composition. The photo-sensitive composition may comprise in part by weight per cent; - polyvinyl alcohol colloid, 2 to 5 parts; alkali metal or ammonium dictranate photo-sensitizer, 2 to 5 parts; phosphor particles, 18 to 25 parts; 1, 4-dioxane, 0À05 to 3 parts, deionized water, to 100%. The cyclic ether also enables organic colloids such as polyvinyl alcohol or acetate to be used which have average molecular weights of from 83,000 to 125,000.