Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C7/00—Multicolour photographic processes or agents therefor; Regeneration of such processing agents; Photosensitive materials for multicolour processes
  • G03C7/30—Colour processes using colour-coupling substances; Materials therefor; Preparing or processing such materials
  • G03C7/407—Development processes or agents therefor
  • G03C7/413—Developers

Definitions

• This invention relates to colour photography and more particularly to developing compositions for use in colour photographic processes.
• a colour image is formed by developing a silver salt image in a photographic element by means of a developing solution which contains an aromatic primary amino developing agent and a dye intermediate (hereinafter referred to as a colour coupler) such that the oxidation products of the developing agent formed during its developing action couple with the colour coupler to constitute a dye in situ with the developed silver image, the dye commonly being anazomethine or quinone-imine dye.
• a developing solution which contains an aromatic primary amino developing agent and a dye intermediate (hereinafter referred to as a colour coupler) such that the oxidation products of the developing agent formed during its developing action couple with the colour coupler to constitute a dye in situ with the developed silver image, the dye commonly being anazomethine or quinone-imine dye.
• the developing agents used in this type of process are usually derivatives of p-phenylene diamine, well-known examples being N.N-diethyl p-phenylene diamine and 2- nited States Patent amino-S-diethyl amino toluene and their salts and sulphur dioxide reaction products.
• These agents unfortunately have a tendency to oxidise in the air and, since the oxidation products will combine with the colour coupler present, the solutions in use acquire, more or less rapidly, a scum consisting mainly of the dye thus formed. This is so serious a difficulty that such developers must frequently be discarded long before they have outlived their useful activity.
• the extent of scum formation depends on the extent of aerial oxidation which occurs, and this in turn is found to be greatest at higher pH values. Accordingly, a balance must be struck between the activity of the developer, which is reduced by lowering the pH of the solution, and the liability of the developer to oxidation, which is increased by increasing the pH of the solution, i.e. some sacrifice of developer activity must be made in order to aviod undue oxidation. Generally, the pH of the solutions is adjusted to about 10.5.
• a photographic developing composition for use in colour developing a developable sliver salt image in a photographic element may comprise an aromatic primary amino developing agent, a colour coupler which is capable of combining with the oxidation products of such developer to form a dye, and hydroxylamine or .a salt thereof, the said. composition on dissolution in water having a pH of .at least 11.25.
• aryl group -R may be a phenyl'or naphthyl group or a corresponding group containing, for example, alkyl, aralkyl, aryl, sulphonic acid or halogen substituents. Specific compounds of value are: 1'
• a photographic developing composition for use in colour developing a developable silver salt image in a photographic element comprises an aqueous alkaline solution of an aromatic. primary amino developing agent, a colour coupler which is capable of combining with the oxidation products of such developer to form a dye, hydroxylamine or, a 'salt thereof and ascorbic acid and/ or a tetronic compound of the formula above set forth.
• the invention further includes processes of colour development employing such solutions.
• hydroxylamine and ascorbic acid or tetronic compound are not unduly critical. Generally a quantity of the orderof 0.5 to 1.5 g./litre of hydroxylfective in reducing, or even eliminating, dye scum. It
• agents. are N.N.-diethyl p-plienylene diamine or '2-a'mino- 5'-diethyl amino .toluene, or:theirsalts. or sulphur dioxide Patented Feb. 2, 1960 reaction products.
• a suitable alkalinity in the developing composition is conveniently achieved by the use of alkali carbonates or, where a high pH is desired, mixtures of tribasic sodium phosphate and dibasic sodium phosphate, these latter compounds being particularly useful owing to their good buffering properties.
• thedeveloping compositions of the invention may include other ingredients common to photographic developers, e.g. alkali, ammonium or amine sulphites and alkali or ammonium bromides. it is also frequently of advantage to include a proportion of ethyl alcohol in the developer.
• the invention accordingly further includes in solid form or in strong aqueous solution a composition of aromatic primary amino developing agent, hydroxylamine and ascorbic acid and/or tetronic compound as defined.
• photographic element which comprises anaqueous alkaline solution of an aromatic primary amino developing agent, a colour coupler which is capable of combining with the oxidation products of such developer to form a dye, a. compound selected fromthe class consisting of hydroxylamine and its salts in a concentration of 0.5 to 1.5 g./litre and a compound selected from the class consisting of ascorbic acid and tetronic compounds of the formula:
• the pH of the developer was in all cases approximately 10.50. It will be seen that while hydroxylamine alone is ineifective at this pH, and both ascorbic acid and a typical tetronic compound afiord only limited protection against scum formation, the combination of the two (developers D, E, F, G and H) shows a very much enhanced protective eflect.
• a photographic developing composition for use in colour developing a developable silver salt image in a photographic element which comprises an aqueous alkaline solution of an aromatic primary amino developing agent, a colour coupler which is capable of combining with the oxidation products of such developer to form a dye, a compound selected from the class consisting of hydroxylamine and its salts and a compound selected from the class consisting of ascorbic acid and tetronic compounds of the formula:
• R is selected from the class consisting of phenyl and naphthyl groups, and phenyl and. naphthyl groups containing alkyl, aralkyl, aryl, sulphonic acid and halogen substituents, and X is selected from the class consisting of the oxygen atom and the imino group.
• a photographic developing composition for use in colour developing a developable silver salt image in a photographic element which comprises an aqueous solution of pH 9 to 11.25 of an aromatic primary amino developing agent, a colour coupler which is capable of combining with the oxidation products of such developing agent to form a dye, hydroxylamine in a concentration of 0.5 to 1.5 g./litre, and 4-phenyl-2 oxytetronimide in a concentration of 0.1 to 0.5 g./litre.
• a photographic developing composition for use in colour developing a developable silver salt image in a photographic element which comprises an aqueous solution of pH 9 to 11.25 of an aromatic primary amino developing agent, a colour coupler which is capable of combining with the oxidation products of such developing agent to form a dye, hydroxylamine in a concentration of 0.5 to 1.5 g./litre, and 4-phenyl-2-oxytetronic acid in a concentration of 0.1 to 0.5 g./ litre.
• a photographic developing composition for use in colour developing a developable silver salt image in a photographic element which comprises an aqueous solution of pH 9 to 11.25 of an aromatic primary amino developing agent, a colour coupler which is capable of combining with the oxidation products of such developing agent'to form a dye, alkali carbonate, hydroxylamine in a concentration of 0.5 to 1.5 g./litre, and ascorbicacid in a concentration of 0.1 to 0.5 g./ litre.
• a photographicdeveloping. composition for use-in colour developing a developable silver salt image in a photographic element which comprises an aqueous solution of pH 9 to 11.25 of an aromatic primary amino developing agent, a colour coupler which is capable of combining with the oxidation products of such developing agent to form a dye, alkali carbonate, hydroxylamine in a concentration of 0.5 to 1.5 g./litre, and 4-phenyl-2- oxytetronimide in a concentration of 0.1 to 0.5 g./litre.
• a photographic developing composition for use in colour developing a developable silver salt image in a photographic element which comprises an aqueous solution of pH 9 to 11.25 of an aromatic primary amino developing agent, a colour coupler which is capable of combining with the oxidation products of such developing agent to form a dye, alkali carbonate, hydroxylamine in a concentration of 0.5 to 1.5 g./1itre, and 4-phenyl-2- oxytetronic acid in a concentration of 0.1 to 0.5 g./litre.
• a photographic developing composition for use in colour developing a developable silver salt image in a photographic element which comprises an aqueous solution of pH 9 to 11.25 of an aromatic primary amino developing agent, a colour coupler which is capable of combining with the oxidation products of such developing agent to form a dye, tribasic sodium phosphate, dibasic sodium phosphate, hydroxylamine in a concentration of concentration of 0.1 to 0.5 g./litre.
• a photographic developing composition for use in colour developing a developable silver salt image in a photographic element which comprises an aqueous solution of pH 9 to 11.25 of an aromatic primary amino developing agent, a colour coupler which is capable of combining with the oxidation products of such developing 0.5 to 1.5 g./litre, and ascorbic acid in a concentration of 0.1 to 0.5 g./litre.
• a photographic developing composition for use in colour developing a developable silver salt image in a agent to form a dye tribasic sodium phosphate, dibasic sodium phosphate, hydroxylamine in a concentration of 0.5 to 1.5 g./litre, and 4-pheny1-2-oxytetronic acid in a concentration of 0.1 to 0.5 g./1itre.

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• General Physics & Mathematics (AREA)
• Silver Salt Photography Or Processing Solution Therefor (AREA)

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  • NL NL226676D patent/NL226676A/xx unknown
• 1957
  • 1957-04-17 GB GB12581/57A patent/GB830625A/en not_active Expired
• 1958
  • 1958-03-31 US US724931A patent/US2923627A/en not_active Expired - Lifetime
  • 1958-04-14 DE DEI14688A patent/DE1057875B/de active Pending
  • 1958-04-17 FR FR1205498D patent/FR1205498A/fr not_active Expired

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