Patent GB-503826-A (GB)
Title: Process and materials for colour photography
IPC: G03C7/333
Filed: 1937-07-07
Abstract: 503,826. Colour photography. KODAK, Ltd. July 7, 1937, No. 7955/39. Convention date, July 7, 1936. Divided out of 503,752. [Class 98 (ii)] The coupling components included in multilayer colour photographic material which combine, during colour development, with the oxidation product of the'developing agent are themselves insoluble dyestuffs or their leuco derivatives containing coupling functions. The coupling function may have been introduced by combining the dyestuff with a residue. The coupling components can, during or after coupling, be converted into the final dye image by simple hydrolysis and/or oxidation. The coupling functions are of five types defined as "phenolic," "amine," "open-chain reactive methylene," "intracyclic reactive methylene," and " sulphonarylamide." The components may be derivatives of anthraquinone, such as acylated aminoanthraquinones, or the compounds obtained by replacement of the chlorine atoms of cyanuric chloride with one molecule of aminoanthraquinone and two molecules of an amino phenol or amino-alpha-naphthol. The compounds synthesized from dyes or from leuco derivatives of dyes and given in Tables Ic and IVb in Specification 503,752, may be used. The compound obtained by condensing nitrobrom-alpha-naphthol with primuline base or derivatives thereof, followed by reduction of the nitro group and condensation thereof of a further'radicle containing a coupling function, and the compounds obtained by condensing primuline with #-chlor-acetyl-alpha-naphthol, 4-#- brom-acetyl-alpha -naphthol, 2-#-brom-acetyl-alphanaphthol or #-chloraceto-amino-alpha-naphthol may all be used as coupling components. The processing is as described in Specifications 503,752 and 503,824. In elements for camera exposure, the coupable derivative can only be added to the upper layer, but in printing elements all layers can contain them-especially in white paper printing elements where the images are weak. Equal coupling speeds are obtained by using conponents which contain coupling functions of the same type, e.g. using amino- or amino-hydroxy-anthraquinone with salicyclic chloride, m-hydroxy benzoyl chloride, or alpha-naphthol-2-carboxylic-acid chloride as acylating agent. In cyanuric chloride, the two chlorine atoms can first be displaced by condensation with amino-anthraquinone or its alkyl derivatives or substitution products and the other chlorine atom by m-amino-phenol or an amino-alpha-naphthol Derivatives of methylene anthrones may be used. Coloured substances are rendered capable of coupling by condensation with acid chlorides of coupling compounds, e.g. amino-malachite green, or a leuco derivative can be condensed with salicylyl chloride. Carboxylic or sulphonic acid chlorides of dyes can be condensed with o, m, or p-aminophenol, amino - alpha - naphthol, aniline or alphanaphthylamine. The latent images are thus developed to yield insoluble indamines. If necessary, the indophenol group is split by the action of acid in the presence of a phosphotungstate or other precipitant and the quinone residue can be reduced to the hydro quinono group or the pyrocatechine group. If a couplable derivative of a dye is added to the middle and upper emulsion layers of a threelayer element, the residual silver bromide of the bottom layer is converted to blue-green with a dissolved colour developer after exposure through the back to red light, or to blue light if a red or yellow filter is between the middle and bottom layers. The insoluble complex salts of the dyestuff derivatives may also be used. The couplable derivatives may also be contained in separate pure gelatine layers situated above or below the appropriate sensitive layers and these may also act as filter layers. The materials used are preferably those described in Specification 500,826'(as open to inspection under Sect. 91). Two and three layer materials sometimes of mixed particle sensitized emulsions of gelatine or collodion, and carrying a sound track in any sensitive layer or in a separate sensitive layer, are described. The insolubility of the compounds is defined. Specifications 376,746, 376,794, 376,795, 440,032, 440,089, 447,092, 468,664, 475,784, 475,786, 498,869, 498,870, 498,871, 498,875, 499,185, 501,003, 503,816, 503,817, 503,818, 503,819, 503,820, 603,821, 503,823, 503,824, 503,825, 503,827, and 503,941 also are referred to.