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
  • G03C7/32—Colour coupling substances
  • G03C7/34—Couplers containing phenols
  • G03C7/344—Naphtholic couplers

Definitions

• F stands for a residue making the coupler diffusion resistant
• A stands for H, halogen or sulfo
• couplers can advantageously be combined with red azo masking couplers.
• the invention relates to an improved color photographic material.
• the invention relates to a color photographic material which contains new cyan-forming couplers and which is improved in its color reproduction, and in particular a material of this type in which the new cyan-forming couplers are used in combination with an azo red masking coupler.
• color side densities of image dyes produced on chromogenic development of multilayered photographic materials can be compensated by masking processes. In color photographic materials, this can be achieved by using so-called built-in masks.
• Masks of this type are produced in the course of the photographic process by using color-forming couplers which have the necessary color for masking the unwanted color side densities of the image dyes.
• Color-forming couplers which are suitable for this purpose generally have the chemical structure of conventional color-forming couplers but at the coupling position for the reaction with the oxidized color developer there is a group, generally an azo dye group, which imparts the color to the color-forming coupler and which is split OK in the reaction with the oxidized color-forming developer.
• the image dye together with its unwanted side densities, is thus produced by the color-forming development in the exposed and developed areas and at the same time the masking coupler, which has the appropriate color for masking the unwanted side densities of the image dye, is destroyed.
• the yellow and magenta side densities measured behind color filters after processing are constant and independent of the exposure.
• the coupler is generally the more highly reactive. It, thereof, removes all the oxidation products of the developer in the region of threshold sensitivity, with the result that the masking coupler cannot exert its masking effect. This shows itself in the fact that in the region of lower densities falsification of color occurs because of the uncorrected side densities, whereas in the region of higher densities a so-called over masking is often observed.
• Another necessary condition for achieving improved color corrected images is, therefore, good kinetic compatibility between the coupler and the masking coupler.
• the known cyan-forming couplers generally do not fulfill the above mentioned requirements, especially when special developer substances are used, e.g. 2-amino-5-(N-ethyl-N-B- methanesulphonarnidoethylamino)-toluene.
• A represents a hydrogen atom, a halogen atom, such as chlorine or bromine, or a sulpho group
• R represents the bifunctional group:
• n 2 or 3
• F represents a radical which renders the compound resistant to diffusion, which radical is linked to the second nitrogen atom of the group R either directly or indirectly via a CO, CO-NH or COO group, e.g. it may represent l. a straight chained or branched alkyl radical containing up to 20 C. atoms, preferably from 10 to 18 C. atoms,
• an acyl radical derived from aliphatic carboxylic acids containing up to 22 C. atoms, preferably from l2 to 18 C. atoms, or derived from aromatic or araliphatic carboxylic acids such as benzoic acid or phenyl acetic acid, the aromatic part of which is linked either directly or indirectly via intermediate groups to a radical which renders the compound resistant to diffusion, for example to one of the radicals mentioned under (I an alkylcarbamyl radical in which the alkyl radical contains up to 20 C. atoms and preferably from 10 to l8 C. atoms, or
• the compounds according to the invention are prepared by known processes. Their method of preparation is explained below with the aid of the example of couplers I, 19 and l, 20.
• Coupler l, 19 were dissolved in of glacial acetic acid at 60 C. The solution was cooled to 40 C., and
• the cyan-forming couplers according to the invention are eminently suitable for the production of color photographic materials. They are highly sensitive and on chromogenic development they yield cyan dyes of great brilliance, very advantageous absorption and only slight yellow and magenta side densities.
• cyan-forming couplers according to the invention may be used especially advantageously in combination with azo red masking couplers, e.g. those described in German Pat. application P 15 97 510.7 and having the following general formula:
• R a hydrogen atom or an acylamino group
• R a hydrogen or halogen atom, but if R represents an acylamino group then R represents a hydrogen atom;
• R a hydrogen or halogen atom, but if R represents a hydrogen atom, then R represents a halogen atom;
• X an amino group, preferably a dialkylamino group
• alkyl radicals contain up to 20 carbon atoms
• the cyan-forming couplers according to the invention, as well as the azo red masks which are to be used together with them according to the invention, may be incorporated with the silver halide emulsion by one of the known methods.
• incorporation is achieved by dissolving the compounds in suitable organic solvents, e.g. in esters of aliphatic carboxylic acids, especially in ethyl acetate, and emulsifying this solution with the silver halide emulsion which is ready for casting.
• This method may advantageously be modified by simultaneous use of oily solvents for couplers. This process also known from US. Pat. specifications 2,304,940 and 2,322,027.
• the couplers or masking couplers are alkali-soluble compounds, they are added to the light-sensitive silver halide emulsions in aqueous alkaline solution.
• the couplers and masking couplers may, of course, be added one after the other to the silver halide emulsion, but they may also be added simultaneously from a common solution.
• the method of addition to the emulsion is not critical, and the most suitable process can easily be determined by a few simple tests.
• Suitable for use as light-sensitive emulsions are emulsions of silver halides such as silver chloride, silver bromide or mixtures thereof, optionally with a small silver iodide content of up to mols percent in one of the conventional hydrophilic binders such as protein, especially gelatine, polyvinyl alcohol, polyvinyl pyrrolidone, cellulose derivatives such as carboxylalkyl cellulose, especially carboxy methyl cellulose, or derivatives of alginic acid.
• the conventional hydrophilic binders such as protein, especially gelatine, polyvinyl alcohol, polyvinyl pyrrolidone, cellulose derivatives such as carboxylalkyl cellulose, especially carboxy methyl cellulose, or derivatives of alginic acid.
• the emulsions may also contain the usual additives e.g. spectral or chemical sensitizers, stabilizers, hardeners and plasticizers.
• Any color-forming developers which contain a primary amino group may be used for development.
• Those of the pphenylene diamine type are preferred, e.g. N,N-dimethyl-pphenylenediamine, N,N-diethyl-p-phenylenediamine, monomethyl-p-phenylenediamine, 2-amino-5- diethylaminotolulene, N-butyl-n-w-sulphobutyl-p-phenylenediamine and 2-amino-5-(N-ethyl-N-B- methanesulphonamido-ethyl-amino)toluene.
• EXAMPLE 1 g. of coupler 1, 20 are dissolved in 60 ml. of ethyl acetate and incorporated by emulsification with 320 ml. of 10 percent gelatine in a known manner.
• the emulsion product contains 1 1 ml. of 10 percent aqueous saponin solution.
• Subsequent processing includes the following baths:
• Hardening bath 0.32 g. of sodium hydroxide 0.5 g. of sodium hexametaphosphate 9.04 g. of soda 20 ml. of 37% formalin Water up to l l.
• a cyan dye is formed in the exposed areas, whereas in the unexposed areas the orange red masking dye is preserved. Sensitometric determination shows that the material is very well masked in the blue and green ranges of measurement.
• EXAMPLE 2 A photographic emulsion containing a coupler and a masking coupler is prepared as described in example 1 and poured on a support but in this case only 200 ml. of the coupler-emulsion product described in example 1 is used per kg. of emulsion.
• Subsequent photographic processing comprises the following baths:
• Light-sensitive photographic material comprising at least one silver halide emulsion layer, which contains a cyan-forming coupler of the following formula I:
• R represents the bifunctional group:
• R a carboxyl or sulpho group; R hydrogen or an acylamino group; R hydrogen or a halogen atom but if R represents an acylamino group then R represents hydrogen; R hydrogen or a halogen atom but if R represents hydrogen then R represents a halogen atom;
• X an alkoxy group, an amino group with up to 20 carbon atoms, or a phenylthio group;
• Y hydrogen or a carboxyl, sulpho or a mono or dialkyl sulfamyl group.

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

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Citations (3)

• 1969
  • 1969-05-03 DE DE19691922628 patent/DE1922628A1/de active Pending
• 1970
  • 1970-04-22 CH CH598870A patent/CH528103A/de not_active IP Right Cessation
  • 1970-04-23 BE BE749373D patent/BE749373A/de unknown
  • 1970-04-28 US US32725A patent/US3632347A/en not_active Expired - Lifetime
  • 1970-04-30 GB GB20774/70A patent/GB1277542A/en not_active Expired
  • 1970-04-30 FR FR7016024A patent/FR2047197A5/fr not_active Expired

Patent Citations (3)

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