Method of applying an organic film to a phosphor layer

Claim 1

IN THE MANUFACTURE OF AN ALUMINUM FLIM-BACKED LUMINECENT PHOSPHOR SCREEN OF A CATHODE RAY TUBE WHEREIN PHOSPHOR PARTICLES ARE DEPOSITED AS A LAYER ONTO THE GLASS SUBSTRATE FROM AN AQUEOUS SUSPENSION THEREOF AN OSRGANIC FILM APPLIED TO THE PHOSPHOR LAYER AND AN ALUMINUM FILM DEPOSITED ON SAID ORGANIC FILM, THE IMPROVED METHOD OF APPLYING AN ORGANIC FILM TO THE PHOSPHOR LAYER WHICH COMPRISES APPLYING, TO THE SURFACE OF THE AQUEOUS PHOSPHOR-SUSPENDING MEDIUM ON TH GLASS SUBSTRATE IN TH CATHODE RAY TUBE BULB, A COMPOSITION COMPRISING BETWEEN 3.5 ANS ABOUT 5%, BY WEIGHT, OF NITROCELLULOSE, A WATER-INSOLUBLE PLASTICIZER THEREFOR AND OCTYL ACETATE DISSOLVED IN A MIXTURE COMPRISING A WATER-SOLUBLE ALCOHOL SELECTED FROM THE GROUP CONSISTING OF A PROPYL ALCOHOL AND A BUTYL ALCOHOL AND VOLATILE ESTER SELECTED FROM THE GROUP CONSISTING OF PROPYL ACETATE AND UTYL ACETATE, THE SAID VOILATILE ESTER BEING THE MAJOR CONSTITUENT IN SAID COMPOSITION; AFTER THE PHOSPHOR LAYER HAS BEEN DEPOSITED ONTO THE GLASS SUBSTRATE, REMOVING THE AQUEOUS PHOSPHOR-SUSPENDING MEDIUM FROM BETWEEN THE PHOSPHOR LAYER AND NITROCELLULOSE FILM WHEREBY THE NITROCELLULOSE FILM SETTLES AND RESTS UPON THE PHOSPHOR LAYER, AND DRYING THE RESULTING ASSEMBLY.