Patent GB-555728-A (GB)
Title: Improvements in photographic materials
IPC: G03C1/835
Filed: 1942-02-11
Abstract: 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-phenylphenol, hydrolyzed colophony, and N:N<SP>1</SP>-ethylenedioxymethylpyridine perchlorate in alcohol, or a solution of 1-phenyl-3-methyl-5- pyrazolone and ethylene glycol-lac ether in alcohol may be added to a silver bromide emulsions. The salts may be used instead of the resins. Specifications 458,664, 458,665, 478,942, 478,983, 479,989, 478,990, 493,952, 496,196, 496,245, 511,180, 519,695, 524,040, 524,154, 524,554, 524,555, 525,874, 525,875, 527,493, 531,246, 531,312, 536,949, 537,696, 537,921, 538,914, 540,365, 540,525, 541,589, 544,134, and 544,135 also are referred to. The Provisional Specification refers also to the incorporation of pigments, dyes, dye-derivatives, and dye-forming substances in sensitive and non-sensitive layers. The process may be applied to filter, antihalation, and emulsion layers. Three-layer materials (a) having a yellow filter layer between the blue- and green-sensitive emulsion layers and a yellow or red filter layer between the green- and red-sensitive emulsion layers and (b) having particles containing a yellow dye (e.g. benzene-azo-resorcinol) in the blue-sensitive layer, particles containing a magenta dye (e.g. Oil Red O or Alcol Fast Red 4 BL) in the green-sensitive layer, and particles containing a blue-green dye in the redsensitive layer are described. Dyes to be incorporated in emulsions for use in the dye-destruction process include imagewise bleachable azo dyes soluble in organic solvents (e.g. n-butyl alcohol) and vat dyes (e.g. anthraquinone dyes). Examples describe filter layers containing (a) Methyl Red and hydrolyzed colophony, (b) 2- hydroxy-5-methoxyazobenzene and butric acid-lac ester, (c) 2:4-dihydroxyazobenzene and ethylene glycol-lac ester, and (d) 2:4-dihydroxyazobenzene and the sodium salt of hydrolyzed colophony; antihalation layers containing (a) Magenta P 120 and hydrolyzed colophony, (b) Malachite Green and hydrolyzed gum mastic, and (c) Ink Blue and the calcium salt of hydrolyzed hard lac ; and mixed emulsion materials obtained (a) by mixing a contrasty silver bromide emulsion sensitized with 5-((2-ethyl-1-benzoxazolylidene)-ethylidene)- 3-ethyl-1-phenyl-2-thiohydantoin and containing hydrolyzed hard lac with a soft silver bromide emulsion containing hydrolyzed hard lac and coating on paper and (b) by mixing a contrasty silver chloride emulsion sensitized as in (a) and containing hydrolyzed colophony and lac-acetic acid ester with a soft silver chloride emulsion containing lac-acetic acid ester. Specification 450,958 also is referred to.