Patent GB-598479-A (GB)
Title: Photographic colour-former dispersions
IPC: G03C7/327
Filed: 1945-06-01
Abstract: A process for the production of a colouryielding photographic element comprises reacting a hydrophilic film-forming aliphatic hydroxyl polymer containing more than 200 carbon atoms in the polymer chain and at least one non-phenolic hydroxyl group for every 8 carbon atoms in the polymer chain and having a light-sensitive silver salt dispersed therein with a dye intermediate and a condensing agent capable of reacting with the polymer and the dye intermediate to provide an ether linkage therebetween.  In a modification, the condensing agent is first condensed with the dye intermediate and the product condensed with the polymer containing the dispersed silver salt.  The polymer may be a cellulose ether or ester such as methyl, hydroxyethyl, or ethyl cellulose or cellulose glycollicacid; a vinyl polymer or interpolymer such as polyvinyl alcohol, a polyvinyl ester such as the chloride, acetate, or chloracetate, a polyvinyl ether such as the methyl or ethyl ether, a polyvinyl acetal such as the formaldehyde, acetaldehyde, or benzaldehyde acetal, a hydrolysed olefine/vinyl ester interpolymer such as one derived from ethylene, propylene, or butene-2, or a hydrolysed interpolymer of vinyl acetate or isobutyrate with a minor proportion of an unsaturated compound such as vinyl chloride, or an alkyl acrylate or methacrylate; deacetylated chitin; alginic acid; glycol polyformal; or carboxyethyl cellulose.  The dye intermediate may be as in Specification 593,088, and the change in water solubility and permeability produced by the introduction of the dye intermediate groups may be similarly balanced.  The condensing agent may be formaldehyde, a formaldehydeyielding substance such as paraformaldehyde, trioxane, or hexamethylenetetramine, a compound capable of forming methylol derivatives such as methylene diacetate or methyl chloromethyl ether, acetaldehyde, benzaldehyde, glyoxal, or a dimethyl derivative of an amide or urea such as dimethylolurea, dimethyloladipamide, dimethyloloxamide, dimethylolmelamine, bismethoxymethylurea, trimethylolmelamine, dimethylolpiperazine, tetramethylolethylene diamine, tetrahydro-1 : 3-dimethyl-5-(b -hydroxyethyl)-S-triazone-2, dimethylolacetone, trimethylolnitromethane, 2-methyl-2-nitro-1 : 3-propanediol, tetramethyloldiphenylolpropane, tetramethyloldiphenylolmethane, N : N1 : N11-tris-(methoxymethyl)-melamine.  N : N1-bis-(methoxymethyl)-uron, N : N1-bis(methoxymethyl)-piperazine, dioxolan, dichlorodioxane, dimercaptomethyladipamide, chlorinated polyalkylene ethers, or adipohydroxamic acid.  A condensation catalyst may be used.  The support for the sensitive layer may be paper, metal, glass, a cellulose derivative, a polyvinyl acetal, or a superpolyamide. Sensitizing dyes, sulphur sensitizing compounds, and antifogging agents may be added to the emulsion before or after coating.  In Example 1, an emulsion is prepared by adding ammoniacal silver nitrate solution for an aqueous alcohol solution of a partially hydrolysed hydrophilic ethylene/vinyl acetate interpolymer also containing sodium dodecylsulphate and potassium bromide and then adding an aqueous solution of resorcinol.  The emulsion is gelled, shredded, and washed, and solutions of terephthaldehyde and 1-m-aminophenyl-3-methyl-5-pyrazolone added.  The emulsion is coated on paper and colour developed or reversal colour developed after exposure.  A diluted gelatino-silver bromide emulsion containing sodium dodecylsulphate may be centrifuged to separate the silver halide, washed, dispersed in water with further sodium dodecylsulphate, and added to an aqueous ethyl alcohol solution of hydrolysed ethylene/vinyl acetate interpolymer.  Dimethylol urea and 1-m-aminophenyl-3-methyl-5-pyrazolone are successively added to this emulsion, which is coated on cellulose nitrate and colour developed or reversal colour developed after exposure.  An emulsion may also be prepared by adding solutions containing : (a) ammonium bromide, potassium iodide, and sodium octadecylsulphate and (b) silver nitrate, ammonium hydroxide, and sodium octadecylsulphate to an aqueous solution of hydrolysed ethylene/vinyl acetate interpolymer containing sodium octadecylsulphate, cooling, adding acetone to precipitate the emulsion, washing the precipitate, shredding, adding an ethyl alcohol solution of the interpolymer containing potassium bromide, and ripening.  The emulsion is heated and solutions of 1-m-aminophenyl-3-methyl-5-pyrazolone, bismethoxymethyl-urea, (or dimethylol oxamide, N : N1-adipyl-bis-(aminomethylpyridinium chloride), glyoxal-sodium bisulphite, dimethylol urea, or dimethylol adipamide) and saponin added.  A cellulose nitrate film may be coated with successive subs of polyvinyl o-sulphobenzaldehyde acetal and partially hydrolysed ethylene/vinyl acetate interpolymer, and then with an emulsion prepared by adding successively to a silver bromide-hydrolysed ethylene/vinyl acetate interpolymer composition naphthoselenacarbocyanine iodide, an aqueous-alcoholic solution of sodium hydroxide and N-(p-bromophenyl)-1-naphthol-2-sulphonamide, dimethylol urea, and saponin.  Multilayer material is prepared by coating over the latter emulsion an emulsion prepared by adding centrifuged silver bromide to polyvinyl alcohol and then successively terephthaldehyde and 1-m-aminophenyl-3-methyl-5-pyrazolone and green-sensitized with erythrosin, then coating with a filter layer prepared by adding alcoholic diphenylcarbazide and ammonium hydroxide to an aqueous alcohol solution of hydrolysed ethylene/vinyl acetate interpolymer containing silver nitrate (or a filter layer prepared by adding a yellow dye such as 4-piperonylbutadienyl-a -pyridinium-stearyl bromide to a solution of the interpolymer) and finally coating with a non-coloursensitized emulsion prepared similarly to the red-sensitized emulsion with p-aminoacetoacetanilide replacing the naphthol derivative.  The material may be processed by reversal colour development.  Specifications 582,093, 598,475 and 598,476 also are referred to.