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
  • G03C5/00—Photographic processes or agents therefor; Regeneration of such processing agents
  • G03C5/26—Processes using silver-salt-containing photosensitive materials or agents therefor
  • G03C5/264—Supplying of photographic processing chemicals; Preparation or packaging thereof
  • G03C5/265—Supplying of photographic processing chemicals; Preparation or packaging thereof of powders, granulates, tablets

Definitions

• the present invention relates to a granular color photographic developer and a method for producing such a developer which can be quickly dissolved.
• Color photographic developers usually contain a number of solid components, for example the actual developer substance, antioxidants, complexing agents, sodium sulfite, alkali donors and alkali halides. Since these compounds can react chemically with one another, they are assembled separately and only mixed immediately after use. Suitable formulations are powders and liquid concentrates, the latter having become more and more established over the years, especially since some developers contain liquid components which, understandably, cannot be formulated in powder form, for example benzyl alcohol.
• the three or four concentrates are then mixed in certain mixing ratios and, if appropriate, with the addition of water with stirring.
• compositions which contain all the solid constituents of a color photographic developer by grinding the constituents so that the maximum of the particle diameter distribution curve is below 10 ⁇ m, subjecting the ground particles to powder agglomeration and drying the granules in vacuo , mixed together and packed in a water vapor-tight manner.
• the invention thus relates to a process for the preparation of a granulated preparation of the solid constituents of a color photographic developer, characterized in that the antioxidant, the developer substance and the alkali donor of a color photographic developer are ground separately to a particle size ⁇ 10 ⁇ m, then optionally with the addition of a granulating liquid and a binder is subjected to powder agglomeration and dried in vacuo, the individual granules are mixed and packed in a water-vapor-tight manner.
• the granules of the solid components of a color photographic developer produced in this way are mechanically stable, of uniform grain size, show a high dissolution rate and unlimited durability, are dust-free and free-flowing.
• the solid constituents are usually comminuted to particle sizes of ⁇ 10 ⁇ m by jet milling.
• the powder agglomeration is preferably carried out in a fluidized bed, the granulation liquid optionally being added to the particles to be agglomerated for example, add 200 ml of water per kg of powder and, if necessary, some binder, for example corn starch.
• the average particle diameter of the granules should preferably be ⁇ 150 ⁇ m and is in particular 150 to 3,000 ⁇ m. In the case of components that are particularly sensitive to oxygen, it is preferable to carry out the grinding, granulating, drying, mixing and packaging under a protective gas, for example nitrogen.
• the other components of the developer such as limescale inhibitors, complexing agents for heavy metal ions, sodium sulfite and alkali halide, can also be processed into granules and mixed into the mixture. For economic reasons, however, it is preferable to grind and granulate each of these additives together with one of the three essential granule components (developer substance, antioxidant or alkali donor).
• Suitable color developer compounds are aromatic compounds of the p-phenylenediamine type containing at least one primary amino group, for example N, N-dialkyl-p-phenylenediamines such as N, N-diethyl-p-phenylenediamine, 1- (N-ethyl-N-methanesulfonamidoethyl) -3 -methyl-p-phenylenediamine, 1- (N-ethyl-N-hydroxyethyl) -3-methyl-p-phenylenediamine and 1- (N-ethyl-N-methoxyethyl) -3-methyl-p-phenylenediamine. More need bare color developers are for example in J. Amer. Che. Soc. 73 , 3106 (1951) and G. Haist, Modern
• Another object of the invention is a granulate mixture containing at least 3 different granules of solid components of a color photographic developer, wherein a granulate contains the antioxidant, a granulate contains the developer substance and a granulate contains the alkali donor.
• the granules are 90 minutes. post-dried at 40 ° C in a vacuum.
• Mixture C Mix D a) Disodium salt of 1-hydroxyethane-1,1-diphosphonic acid 34 g --- b) sodium sulfite 39 g 39 g c) ethylenediaminetetraacetic acid --- 24 g d) potassium carbonate 336 g 336 g e) sodium hydrogen carbonate 15 g 15 g f) potassium bromide 15 g 15 g 439 g 429 g
• the individual granules A, B, C and D are mixed in the following weight ratio in a laboratory mixer, whereby work must be carried out with the exclusion of moisture: Granules A 2.4 g Granules B 4.52 g Granules C 21.95 g Granules D 21.45 g total weight 50.32 g
• the mixed granulate is packed in paper bags lined with plastic and aluminum foil, with the exclusion of moisture (conduction of very dry air), which are sealed immediately.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Silver Salt Photography Or Processing Solution Therefor (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Cosmetics (AREA)
• Anti-Oxidant Or Stabilizer Compositions (AREA)

Applications Claiming Priority (2)

Publications (3)

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Family Applications (1)

Country Status (4)

Cited By (8)

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Family Cites Families (10)

• 1988
  • 1988-09-03 DE DE3830023A patent/DE3830023A1/de not_active Withdrawn
• 1989
  • 1989-08-18 US US07/395,598 patent/US4923786A/en not_active Expired - Lifetime
  • 1989-08-22 DE DE58909852T patent/DE58909852D1/de not_active Expired - Fee Related
  • 1989-08-22 EP EP89115441A patent/EP0358034B1/fr not_active Expired - Lifetime
  • 1989-09-02 JP JP1226400A patent/JP2793853B2/ja not_active Expired - Lifetime

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