Patent GB-541589-A (GB)
Title: Improvements in and relating to light-sensitive photographic emulsions
IPC: G03C7/388
Filed: 1940-02-24
Abstract: 541,589. Photographic light-sensitive materials. KODAK, Ltd. (Eastman Kodak Co.). Feb. 24, 1940, No. 3497. [Class 98 (ii)] A liquid solution of a colour coupler, dye, dye-derivative, or dye-forming substance and an oil former, i.e. a substantially water-insoluble high-boiling organic crystalloidal material which will dissolve the colour coupler or other compound and form a solution remaining liquid at any temperature likely to be encountered in the storage, use, or processing of an emulsion containing it, is dispersed in the water-soluble binder of a silver-salt emulsion. The process is applicable to single- or multi-layer material for taking or printing on to material for producing sound records. The use of liquid colour couplers is referred to. Mixtures of colour couplers and of oil formers may be employed. The oil former is preferably removable in processing, and preferably contain one or more polar groups such as halogen atoms or hydroxyl, carboxylic acid, amide, or keto groups. The water-soluble binder of the emulsion may be gelatine, agar-agar, a synthetic resin, or a natural gum. The liquid solution may be dispersed in water or gelatine solution or in any aqueous colloidal binder miscible with the silver halide emulsion. A dispersing agent may be used. A solution of colour coupler and oil former in a low boiling solvent, e.g. butyl acetate, with or without a dispersing agent, is dispersed in water or gelatine solution, the low boiling solvent removed by evaporation, and the resulting dispersion mixed with the silver halide emulsion. Numerous oil formers are specified including acids, alcohols, amides, amide derivatives, carbonates, esters, ketones, phenol ethers, phosphate esters, sulphonamides and derivatives thereof, sulphones, and ureas. Numerous colour couplers are referred to. The film support may be cellulose ester, synthetic resin, metal, or paper, and may carry the customary three emulsion layers with a yellow filter layer between the top and middle emulsion layers. The colour coupler, oil-former, and low boiling solvent may be mixed in a tank, water containing a dispersing agent added and the mixing continued. The mixture is passed through a pipe to a colloid mill or homogenizer, and then passed by a pipe to a steam bath where the low boiling solvent is removed. The dispersion is passed through a pipe to a container where it is mixed with a gelatino silver halide emulsion, and the resulting emulsion is passed through a pipe to a coating hopper where it is coated on a film base. In an example, a solution of 2-lauryl-4-chlorophenol in 1:2-dimethoxybenzene is added to water containing "Gardinol WA" (Registered Trade Mark), and the mixture stirred, passed through a colloid mill, and added to a silver halide gelatine emulsion, which is coated on a support and dried. On development of the exposed emulsion with 2-amino-5-diethylaminotoluene and removal of silver, a blue-green dye image is obtained. In a second example, a solution of 5-(N-benzyl:N- naphthalene-sulphonamino)-1-naphthol in ethyl acetate and ethyl N:N-di-n-butyl-carbonate is added to an aqueous solution of sodium tri-isopropylnaphthalene sulphonate and glycerol monostearate, and, after emulsification, the mixture is added to a silver halide gelatine emulsion. In a third example, a solution of 1-p-phenoxyphenyl- 3-n-amyl-5-pyrazolone in dimethyl phthalate and n butyl acetate at 95 F. is added to a silver halide gelatine emulsion, also at 95 F., and the mixture is emulsified, coated, and dried. In a fourth example, a solution of 2-cyanacetylcoumarone-5-(N-n-amyl-p-tert-amylsulphonanilide in methyl o-methaxybenzoate, n-butyl acetate, and ethyl acetate is dispersed in an aqueous solution of "Gardinol WA" (Registered Trade Mark), the ethyl and n-butyl acetates evaporated off, and the dispersion added to a silver halide emulsion. In a fifth example, a solution of n-propyl p-benzoylacetaminobenzenesulphonate in methyl ptoluenesulphonate is dispersed in a 2 per cent gelatine solution at 50 F. and the resulting dispersion added to a silver halide gelatine emulsion. In a sixth example, a solution of N-(4-benzoylacetaminobenzenesulphonyl) : N-benzyl-mtoluidine in ethyl benzylmalonate and ethyl acetate is emulsified in an aqueous solution of "Gardinol WA" (Registered Trade Mark). In a seventh example, an aqueous dispersion of a trio-cresyl phosphate solution of 1-hydroxy-2-(N-iso amyl :N-phenyl)-naphthylamide is added to a polyvinyl alcohol silver halide emulsion and after emulsification is coated. A similar emulsion may be made using an aqueous dispersion of a tri-ocresyl phosphate solution of 1-p-laurylphenyl-3- methyl 5-pyrazolone. In a three-layer material, one or more of the layers may contain colour couplers not associated with oil formers. Oil formers such as α-naphthol acetate, acetyl-N- butylaniline, acetylmethyl-p-toluidine, methyl phthalate, butyl o-methoxybenzoate, 1:2-dimethoxybenzene, N : N<SP>1</SP>-diphenyl-N<SP>1</SP> : N: diethylurea, and ethyl N:N<SP>1</SP>-di-n-butylcarbonate produce a shift in the absorption maximum of the dye formed. A small quantity of a water-soluble solvent for the colour coupler, such as diethyl ketone or n-butyl alcohol, may be incorporated in the developing solution. Specifications 458,664, 458,665, 474,353, 475,784, 475,786, 478,933, 478,934, 478,942, 478,983, 478,984, 478,985, 478,986, 478,989 478,990, 478,991, 493,952, 496,195, 496,196, 496,245, 503,752, 503,825, 503,826, 503,827, 503,941, 509,707, 516,536. 519,695, 524,040, 524,154, 524,554, 524,555, 524,557, 525,874, 525,875, 527,493, 528,433, 531,246, 531,312, 536,673, 536,939, 537,696, 537,921, and 538,914 are referred to.