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
  • G03C7/28—Silver dye bleach processes; Materials therefor; Preparing or processing such materials

Definitions

• This invention relates to a method of processing photographic color pictures, and particularly to N-substituted iso'alloxazines as accelerators for dye bleach baths used in producing dyestuff images from dyed silver images.
• the latter image must be treated with a bleach bath which decolorizes or bleaches the dyestuff present in the photographic layer in the areas where the metallic silver is present.
• a bleach bath which decolorizes or bleaches the dyestuff present in the photographic layer in the areas where the metallic silver is present.
• azo dy s the substantivezand acid-typ althou h some basic vat dyes and alizarines may also be employed.
• the bleaching or decolorization of the dyestuff is accomplished in a bleach bath in which there occurs a simultaneous decolorization of the dye with an oxidation of the metal image at the points where silver is present, i. e., the metallic silver is converted into a silver compound which may be removed subsequently by fixation in a solution of hypo.
• the bleach baths employed in this process, consist of an aqueous solution of a mineral acid or a mineral acid containing an alkali halide, such as potassium iodide, ammonium chloride, or both.
• an alkali halide such as potassium iodide, ammonium chloride, or both.
• Such baths require a relatively long treating time so as to destroy the dyestuff present in situ with the silver image.
• Long treatment in bleaching solutions of high acidity has the tendencyto soften-the gelatin of the photographic emulsion containing a silver image and bleachable azo dye.
• bleaching solutions of high acidity has the tendencyto soften-the gelatin of the photographic emulsion containing a silver image and bleachable azo dye.
• celerators they are highly colored substances carriers becoming readily reduced by the action of the bleach solution with concomitant oxidation of th asilverimage and destruction ot-the y in situ therewith.
• R represents an aliphatic group, e. g., methyl, ethyl, propyl, butyl, amyl, hexyl, etc., hydroxyalkyl, e: g hydroxyethyl, hydroxypropyl, hydroxybutyl', etc., dihydroxyalkyl, e. g., dihydroxypropyl, dihydroxybutyl, dihydroxyamyl, etc.,
• polyhydroxyalkyl e. g d-ribityl (from d-ribose), l-arabityl (from l-al abinose), d-lyxityl (from dlyxose), d-dulcityl ffrom d-galactose), d-mannityl (from d-mannose), d-sorbityl '(from'd-glucose), etc.
• phosphoric acid esters and the mono-, di-, and tri-acetic and succinic acid esters thereof, amino-alkyl group e.
• phenyl, naphthyl, etc. aralkyl, e. g., benzyl, phenylethyl, menaphthyl, and the like
• Z represents the atoms necessary to complete an aromatic or heterocyclic ring, e. g., benzene, naphtholene, anthracene, etc., piperidine, pyridine,,pyrimidine, quinoline, methylenedioxy, isopropylidenedioxy, and the. like.
• the aromatic and heterocyclic rings maybe substituted in the various positions by alkyl, di-alkyl,
• N-substituted isoalloxazines gfiavinsl although colored substances rangingijrfrom reddish-orange to yellow in color, are not substantive to gelatin, do not stain the gelatinilayer, and do not afi ect the quality of the final imagep
• N-substituted isoalloxazines employed in accordance with the present invention:
• N-substituted isoalloxazines 'a-re generally prepared by the condensation of an N- substituted o-aminoaniline and alloxan.
• the N- alkyl isoalloxazines, with an alkyl group in 10- position higher than methyl (see illustration 1), can be prepared by a method analogous to the one described by Tishler et al., J. Amer. Chem. Soc. 67, p. 2165, 1945, by reacting a 2-alkyl substituted o-phenylenediamine with 5,5-dichlorobarbituric acid.
• Isoalloxazines with an alkyl group in either '7- and S-pcsition or both higher than methyl or ethyl, can also be prepared by Tishler et al.s method by using N-alkyl substituted,phenylenediamine derivatives with the proper alkyl substituents in the 4-, 5-positions as starting materials.
• the monophosphoric acid esters of the polyhyg droxy isoalloxazines can be prepared by the method outlined in Ber. 68, p. 383, 1935. 'The corre ponding triacetates can be'prenaredby the method outlined in Ber. 69, p. 1545, 1936.
• the compound shown in illustration 29 is prepared by treating 4,5-methylenedioxy-o-phenylenediamine with alloxan and methylating the re-- sulting product with dimethyl sulfate in a manner analogous to the method described in Ber. 67, p. 1942, 1934..
• the compound'shown inillustr'atioh' 30 is prepared by treating 4-chloro-5-nitroisoproylidenedioxybenzene with. methylamine, the 4-methy1- amino-5-nitro derivative is catalytically reduced and the reduced compound treated with 5,5-dlchlorobarbituric acid.
• N-s ubstituted isoalloxazines can bereduced to form leuco derivatives which can be re-oxidized with considerable case, a factor which greatly adds to their value as accelerators in accordancewiththe present invention.
• the reduction can be carried out by wellknown chemical means, for example, withsodium hydrosulfite (Ber. 66,319, 1933), with hydrogen in the presence of palladium oxide (ibid. p. 5'76), or with zinc dust (Ang. Chem. 47, 318, 1934); it can also be effected with the aid of enzymes which are contained in yeast, muscle, liver, heart, brain and kidney tissue (Ber. 66, 1298-1302, 1933).
• the N-substituted isoalloxazines may be employed in any mineral acid bleach bath, such as, for example, hydrochloric, hvdrobromic, hydroiodic or phosphoric acid, with or without the presence of an alkali halide, such as sodium or pottassium bromide or, iodide,isodium chloride, ammonium chloride, and the like.
• an alkali halide such as sodium or pottassium bromide or, iodide,isodium chloride, ammonium chloride, and the like.
• the concen-- tration of the acid to'be employed is dependent upon the character of the gelatin constituting the photographic coolr "emulsion layer or layers.
• the concentration of the acid ranges up to 2 N. I prefer, however, to employ a concentration up to 1 N.
• the amount employed as catalysts is not critical. The higher the amount within practical limits the greater the catalytic activity. amount as small as 0.005 gram per liter of bleach bath showed an appreciable bleaching action in sliver bearing images.
• I EX LE I -Three kilograms of a wet gelatino silver halide emulsion, containing about 10% gelatin, 445% of silver-brorrioicdide, 10 cc. of a 10% solution ofsaponin,and 10 grams of d-1 neny1 big'uanide hydrochloride were separated into three equal portionsof 1 kilogram each and utilized in the preparation of the final red, green, and blue sensitive emulsions.
• EXAMPLE III A halogen silver-bearing layer colored with Diamine Pure Blue FF (Schultz Farbslofitabellen 1931, an 8d., #308) was treated with-a bleach solution of the following composition:
• the dye was completely bleached within 10-15 minutes.
• R represents a member selected from the class consisting of aliphatic and aryl groups
• Z represents the. atoms necessary to: completea member selected from the class consisting of aromatic and heterocyclic ring systems.
• R represents a member selected from the class consisting of aliphatic and aryl-groups, and Z represents the atoms necessary to complete a memberselected from the class consisting of aro-;

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Silver Salt Photography Or Processing Solution Therefor (AREA)
• Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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Applications Claiming Priority (1)

Publications (1)

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Citations (3)

• 0
  • BE BE486550D patent/BE486550A/xx unknown
• 1947
  • 1947-12-30 US US794822A patent/US2541884A/en not_active Expired - Lifetime
• 1948
  • 1948-12-14 GB GB32325/48A patent/GB651124A/en not_active Expired
  • 1948-12-24 DE DEP26709A patent/DE824884C/de not_active Expired
  • 1948-12-29 CH CH285165D patent/CH285165A/fr unknown
  • 1948-12-29 CH CH280857D patent/CH280857A/fr unknown
  • 1948-12-29 FR FR991224D patent/FR991224A/fr not_active Expired

Patent Citations (4)

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