Patent GB-503940-A (GB)
Title: Improvements in the production of colour photographic picture films having sound tracks
IPC: G03C7/24
Filed: 1937-07-07
Abstract: 503,940. Kinematograph colour films bearing sound-records. KODAK, Ltd. July 7, 1937, No. 2600/39. Convention date, July 7, 1936. Divided out of 503,752. [Class 98 (ii)] A three-colour photographic picture film having a sound track is produced by recording the sound image on the side of a film having three differentially colour sensitized silver halide emulsion layers inseparably coated on the same support and each containing a coupling component insoluble in water or aqueous sodium carbonate solution and processing the film with an alkaline coupling developer to give a dye plus silver image. The coupling components are not more soluble than the most soluble of tri-alpha-naphthol triazine, alpha-naphthol- 2-carboxylic acid-alpha (or #)-naphthylamide, alpha-naphthol-4-benzoyl ketone, and the hydrazinc of the last-named. A negative or positive sound image may be printed with write light on all three layers, and then appears black, or may be printed or on one or two of the layers, when it appears coloured. The sound track maybe printed after drying of the film at any desired stage in the processing. The border of the film may be covered at first and the sound record printed as a primary or reversed silver image in one, two, or three of the layers before or after completion of the three-colour image. Components having different coupling speeds may be added to the different emulsions, one component coupling in the presence of borax and another component coupling only in the presence of sodium carbonate. The emulsions may be treated separately and coupling developers of different coupling speeds may be employed. The components may be added to the emulsions in amounts of 3 to 20 grams per litre of emulsion. The coupling developers may contain from 0À5 to 2À0 per cent of developing agent and about 5 per cent of sodium carbonate or the equivalent of weaker alkali. The components may be disposed in gelatine solution and the latter added to the emulsion. The components may be deposited on or adsorbed by the silver halide grains, may be formed within the emulsion, preferably after ripening, may be precipitated in emulsions of low gelatine content and gelatine added later, or may be precipitated in centrifuged silver bromide emulsion or in silver bromide separated from a gelatine emulsion after dispersion in water or glycerine or other inert water-miscible liquid, the resulting material being redispersed in gelatine, washed and sensitized. The components may be added in alcoholic alkaline solution to the emulsion and precipitated therein by acid. A yellow filter may be arranged above the blue-sensitive emulsion, and a colloidal silver anti-halation layer may be arranged on either side of the support. The material may be processed directly by colour development, by black-and-white development, fixing, bleaching, and colour development, or by reversal colour development. The material may have a top blue-violet sensitive layer, a middle yellow and green sensitive layer, and a bottom red sensitive layer, or a top blue-violet sensitive layer, a middle red and orange or infra-red sensitive layer, and a bottom yellow and green sensitive layer, or a top red sensitive layer, a middle yellow-green sensitive layer, and a bottom blue sensitive layer. Strongly swelling gelatine is used for the filter layers and the emulsions. A yellow filter may be arranged between the blue-sensitive and the middle layer, and a green, red-orange, or yellow filter or a colourless gelatine layer may be arranged between the middle and bottom layers. The emulsions may be coated on the support in reverse order and the exposure made through the support. The bottom layer may be a highly sensitized collodion emulsion or a hardened gelatine emulsion in which part of the gelatine is replaced by agar-agar, polyvinyl alcohol, or other less swelling colloids. The support may be of cellulose acetate, regenerated cellulose or other synthetic colloid. The sound track may be of variable area type or a combination of the variable density and variable area types, and may be printed in a fourth infra-red sensitized layer. Printing may be effected through the antihalation layer. The development of the original latent images with a neutral developer such as ferrous oxalate or hydroquinone acetone sulphite and the rendering developable of the residual silver halide by means of a fogging agent such as thiosinamine is referred to. Specifications 376,746, 376,794, 376,795, 440,032, 440,089, 447,092, 499,185, 500,826 (as open to inspection under Sect. 91), 503,752, 503,816, 503,817, 503,818, 503,819, 503,820, 503,821, 503,823, 503,824, 503,825, 503,826, 503,827, and 503,941 are referred to. Reference has been directed by the Comptroller to Specification 476,672.