| 摘要 |
906,330. Photographic films. DU FONT DE NEMOURS & CO., E.I. Dec. 5, 1960 [Dec. 31, 1959], No. 41830/60. Class 98 (2). A photographic printing film comprises a transparent hydrophobic film base coated on one side with an antihalation layer having a water-permeable colloid binder and containing besides the antihalation compound a finely divided inorganic white pigment of average particle size 0.1 to 2 microns, and on the other side a water-permeable colloid layer containing a finely divided inorganic white pigment of average particle size 0.1 to 2 microns but not containing an antihalation compound, said colloid layer being overcoated with a photographic silver halide emulsion layer. The white pigment may be titanium dioxide, barium sulphate, calcium sulphate or zinc oxide, and the antihalation compound may be manganese dioxide. The water-permeable colloid layer or antihalation layer binder may be of gelatin, casein, albumin, agar-agar, polyamide, polyvinyl alcohol, polyacrylamide or polyvinylacetals, or gelatin mixed with polyvinyl-N- vinyllactams, butadiene/acrylonitrile copolymers, vinyl acetate/vinyl stearate copolymers, styrene/butadiene copolymers or alkyd and acrylic resins. In the examples the film base is of polyethylene terephthalate subbed with a vinylidine chloride/methyl acrylate/itaconic acid copolymer as described in Specification 786,176. This may be further coated with a layer of gelatin before the emulsion layer is applied. The binder for the antihalation layer is gelatin. Matting agents such as silica or starch may be added to the emulsion layer. Specifications 547,060, 578,079, 718,422, 766,290, Canadian Specification 562,672 and U.S.A. Specifications 2,203,767 and 2,626,867 also are referred to. |
