| 摘要 |
<p>A fluorescent screen comprises (1) a thin flexible support, (2) an adhesive layer of a chloro-sulfonated addition polymer of an olefin of 2-5 carbon atoms containing fine particles of TiO2, (3) a thin flexible layer of phosphor particles in an organic macromolecular polymeric binder and optionally, (4) a protective layer of organic polymer; at least one of the layers contains an amino coumarin brightening agent. The phosphor may be, e.g., cadmium tungstate, zinc sulfide, zinc cadmium sulfide, zinc orthosilicate or barium or lead sulphate; the phosphor particles are preferably 4-40 m , and the phosphor layer be 10-60 mil. when wet, 1-20, preferably 4-14, mil. thick dry. The flexible support may be paper or metal foil, e.g. aluminium, or an organic polymer, e.g. cellulose acetate, cellulose propionate, cellulose acetate butyrate, ethyl cellulose; polyethylene, p.v.c., vinylidene chloride, vinyl acetate, acrylonitrile, styrene and isobutylene polymers; polystyrene; and linear polyesters, e.g. polyethylene terephthalates. The support is from 0.25 to 30, preferably 10 mil. thick, and may contain or carry a dye or finely divided pigment, e.g. titanium dioxide, lithopone, magnesium carbonate, aluminium oxide, carbon black; or may be metal coated, e.g. with aluminium; this reflective coating may be 0.3 to 1 mil. thick. The protective layer ((4) above) may be of cellulose nitrate or acetate, or a mixed resin containing poly(methyl metha-crylate), poly-(isobutylmethacrylate) and vinyl chloride/vinyl acetate copolymer, 0.5 to 1.5 mil. thick. The phosphor may be held in a polyvinyl butyral binder, which may be mixed with a plasticizer, e.g. silicone fluids, triethylene glycol-di-(2-ethylhexoate), triethylene glycol-di-(2-ethylbutyrate), glycerol monolaurate, pentaerythritol-tetracetate, di-butyl phthalate, di-butyl sebacate, butyl ricinoleate. Specifications 727,705, 829,268 and 929,184 are referred to.</p> |
