GB673459A - New or improved multilayer light-sensitive photographic elements - Google Patents

Abstract

673,459. Multilayer colour photographic element. KODAK, Ltd. Nov. 22, 1950 [Nov. 23, 1949], No. 28534/50. Class 98 (ii). A support as of cellulose ester, synthetic resin or paper has a blue sensitive silver halide emulsion layer adjacent thereto, and red and green sensitized silver halide layers in either order superimposed on the blue sensitive layer, and there is present in a non-light sensitive layer over the latter, or in one or both of the red and green sensitized layers, a coloured material which absorbs red or green light or both, the emulsion layers not containing image forming coloured material. The blue sensitive layer is last to be hit by exposing light and therefore usually requires a higher blue light speed than an outermost blue sensitive layer, and the coloured material present in the element is to reduce light scattering in the highly sensitive innermost blue layer by red and green light reaching it after passing through the upper layers. Action of blue light on the upper layers is minimized by using emulsions principally of silver chloride therein; or by exposing the entire film through a yellow filter which does not absorb all the blue light to which the innermost layer is sensitive. Processing is to the usual subtractive colours, and couplers may be present in the emulsion layers. The coloured material in the element may be dye or pigment and may be blue, cyan, magenta or red. On top of a blue sensitive silver bromide emulsion on the support there may be (a) green sensitized silver chloride emulsion containing a blue dye and then red sensitized silver chloride emulsion; (b) red sensitized silver chloride emulsion containing red dye with superimposed green sensitized silver chloride emulsion; (c) blue interlayer and uncoloured red and green sensitized chloride emulsions. The aluminium lake of aurin tricarboxylic acid may be used as green light absorbing material and Prussian Blue or related iron blues or dyes as described in Specifications 506,385, 606,141, 654,266, 658,560 as red light absorbing material. The coloured materials are usually removed in processing but in camera films where this is not essential a dispersion of copper phthalocyanine in gelatin may be used. Specifications 283,765, 321,998, [both in Class 98 (ii)], and 541,589 also are referred to.