Photographic materials

555,728. Photographic materials. KODAK, Ltd., and KNOTT, E. B. Feb. 11, 1942, No. 1779. [Class 98 (ii)] In photographic material having one or more light-sensitive silver salt emulsions in watersoluble colloid binder on one or more supports, at least one of the emulsions contains a dyeforming substance and a hydrolyzed natural resin or a salt thereof or an ester, ether or ether-ester of a hydrolyzed natural resin, or an ester, ether or ether-ester of a natural resin, but not the salt of a hydrolyzed lac. The dye-forming substance may be a colour coupler, a leuco dye, or a substance to be treated for the image-wise production of dye for the diffuse production of dye for subsequent dye-destruction. The material may have two or more (e.g. three) emulsion layers on a single support, preferably superimposed on one side of the support. The dye body may be dissolved or dispersed in a hydrolyzed natural resin or salt thereof or an ether, ester, or ether-ester of a natural resin (but not the salt of a hydrolyzed lac) and the solution or dispersion mixed with the colloid binder of the emulsion. The resins include lacs, colophony, and certain fractions of copals, dammar, mastic, and sandarach. Lacs are bleached and de-waxed. The resins are hydrolyzed to any desired degree with caustic soda. A wetting agent may be added to the resin solution. Resin derivatives specified are hydrolyzed lac, soft lac, hard lac, colophony, mastic, sandarach, copals, dammars, acetic acid, butyric acid, lauric acid, stearic acid, rosin, oleic acid, linseed oil, and phosphoric acid-lac ester ; fatty-acid-lac-glycerol esters ; glycol ether-crotonic and cinnamic esters of lac ; and similar esters and ethers of the other resins and hydrolyzed resins . Hydrolysis (with NaOH) and bleaching (with NaOC1) may be effected simultaneously. In materials such as the double- and triple-layer elements of Specification 503,752, the red-sensitive emulsion may have particles containing a colourcoupler for blue-green, the green-sensitive emulsion particles containing a colour coupler for magenta and the non-colour-sensitized emulsion particles containing a colour-coupler for yellow. In example 1, p-nitrobenzyl cyanide, hydrolyzed soft lac, and "Lubrol W" (Registered Trade Mark), are dissolved in alcohol and acetone, and mixed with a silver bromide emulsion. The exposed material may be developed with a developer containing as developing agent p-diethylaminoaniline. In further examples, a solution of o-phenylph