IMPROVEMENTS IN AND RELATING TO ELECTRO-PHOTOGRAPHIC REPRODUCTION

1361990 Electro-photographic materials GESTETNER Ltd 10 Aug 1972 [12 Aug 1971] 37894/71 Heading G2C An electro-photographic sheet exhibiting low light fatigue comprises a support coated with a dispersion of dye-sensitized ZnO in a binder comprising 3 to 100 wt per cent of polyvinyl butyral wherein the extent of butyralation is at least 85%. In an example, the binder is polyvinyl butyral having a hydroxyl content of 9 to 13%, a butyral content of about 88%, an acetate content of 0 to 2À5% and an acid value below 1, and the photo-conductive composition also includes alezarin cyanine green, erythrosin, dibromofluorescein or cyanoxin, phthalic anhydride and plasticizer.