Patent GB-540366-A (GB)
Title: Improvements in and relating to photographic materials
IPC: G03C7/388
Filed: 1939-12-29
Abstract: 540,366. Colour photography. POTTS, H. E. (Eastman Kodak Co.). Dec. 29, 1939, No. 32967. [Class 98 (ii)] Colour photographic material comprises a photographic emulsion consisting of a silver salt emulsified in a water-soluble binder, such as gelatine, having distributed through it fine, discrete particles of a water-insoluble water-permeable gum or resin containing a pigment dye, leucodye, dye derivative, or dye-forming substance, such as a colour coupler, and containing also a high boiling solvent or plasticizer for the gum or resin. The material may have a number of differently colour-sensitized emulsions on one or more supports, at least one of the emulsions being of the above type. In material bearing a single support, all of the emulsions on that side of the support on which more than one emulsion is located are of the above type. In three-layer material, at least one of two adjacent emulsion layers is of the above type. The solvents may have free hydroxyl groups or may be esters. Solvents specified are the monobenzyl and monophenyl ethers of ethylene glycol; the monoethyl, mono-n-butyl, and diethyl ethers of diethylene glycol; diethylene glycol monobutyl ether monoacetate; dimethyl, di-n-butyl, dibenzyl, and B-ethoxyethyl phthalate ; heptadecanol, n-hexanol, octyl alcohol; benzyl benzoate; tripheryl and tri-o-cresyl phosphate; ethyl palmitate; methyl abietate; B-ethoxyethyl sebacate, maleate, and adipate; ethylene glycol dilaurate; p-toluenesulphon-anilide; tripropionin; trivalerin; monoacetin; and triacetin. The solvents are used in amounts from 5 to 50 per cent of the amount of the gum or resin. The resin may be gum mastic, gum dammar, gum sanderach, gum elemi, polystyrene, polymethyl-methacrylate, polyvinyl acetate, or a coumarone-indene resin. An alternative water-soluble binder is agar-agar. At least one emulsion layer may be of the kind described in Specification 524,154. The silver halide may be silver bromide, chloride, or chlorobromide. Blue-sensitizing dyes may be used. A sound track may be provided in one or more of the picture emulsions or in a separate emulsion. A support of cellulose nitrate or acetate or of paper may be used. In an example, the resin is polyvinyl acetate or acetal, and the high-boiling solvent ethylene glycol mono-benzyl ether. As diluent n-butyl acetate is employed, and the mixture containing a colour coupler is mixed with an aqueous solution of the disposing agent known under the Registered Trade Mark " Gardinol " and the n-butylacetate and some of the water boiled off. The dispersion is added both to a red-sensitive and to a green-sensitive emulsion, which are coated on a support with an intermediate yellow filter layer (or alternatively the material is dyed yellow throughout, the colour coupler for the red-sensitive emulsion may be 1-naphthol-2-carboxylic acid-α-naphthylamide or 5-phenoxyacet-amino-1-naphthol, and for the green-sensitive emulsion n-propyl-p-benzoylacetaminobenzene sulphonate or 2-cyanoacetylnaphthalene - sulphon-N-methylanilide. In a second example, the resin used is polyvinyl acetate or acetal or polymethylmethacrylate, the high-boiling solvent is di-n-butyl phthalate, benzylbenzoate, tri-o-cresyl phosphate, or tri-nvalerin, and the bottom red-sensitive emulsion layer has added thereto a dispersion containing 5-phenoxyacetamino-1-naphthol, the middle greensensitive layer a dispersion containing 2-cyanoacetyl-5-benzoylaminocoumarone, and the top non-colour sensitized emulsion a dispersion containing w-benzoylacet-o-chloranilide. A yellow filter layer is provided between the middle and top layers. Specifications 447,748, 475,784, 475,786, 505,834, 524,554 and 540,525 also are referred to. The 'Provisional Specification refers also to the use of cellulose derivatives such as esters in place of the gum or resin, to hardening with chromium salts, to the use of plasticizers of camphor, alkyl or aryl phosphates, and urethane, and to the use of monoacetin, triacetin, and ethylene glycol monomethyl ether to increase the porosity of the cellulose compounds.