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

• This invention relates to photographic developer compositions the components of which are mutually compatible and can, therefore, be packaged for merchandising as a mixture in a hermetically sealed package.
• photographic developer mixtures are commonly known as single-powder photographic developers, and the present invention more particularly relates to single powder developers containing lithium hydroxide monohydrate as an alkali component of the single powder developer.
• photographic developer powders have traditionally been packaged with the developing agents separated from the alkaline components to prevent interaction. More recently it has been disclosed that some developer mixtures may be protected by the addition of certain protectants so that the developing agents may be mixed directly with the other components of the developer and the resulting developer mixture can be packaged as a single powder developer.
• Such single powder developers may contain, for example, an organic developing agent such as monomethyl p-aminophenol sulfate, hydroquinone, p-aminophenol hydrochloride, p-aminophenol sulfate, pyrogallol, p-hydroxyphenyl glycine, catechol, diaminophenol hydrochloride, and suitable mixtures thereof, stable alkaline butler salts such as sodium carbonate monohydrate, sodium metaborate tetrahydrate (NazB2O4.4H2O) and sodium tetraborate pentahydrate (NEIZBaO'LSHZO); and protectants such as boric anhydride, metaboric acid, phthalic anhydride and sodium or potassium bisulfites and metabisulfites and may also contain the other well known ingredients normally present in a developer such as sodium sulfite and potassium bromide, the normal and known function of the alkali sulfite being that of preservative, lessening the oxidation
• potassium bromide is that of a inhibiting fog silver image.
• Another object of this invention is to provide single powder developers containing lithium hydroxide from which developing solutions which are colorless, fully balanced and of a proper degree of activity can be prepared.
• Another object of this invention is to provide a noncaking single powder developer containing lithium hydroxide monohydrate.
• a further object of the invention is to provide a single powder photographic developer containing lithium hydroxide monohydrate and one or more protectant compounds to prevent interaction of the organic developing agents and the alkaline components and thereby prevent deterioration of the single powder developer.
• Lithium hydroxide monohydrate is also compatible with alum hardening and fixingbaths which may be used after development. v
• lithium hydroxide monohydrate is readily soluble in water yet it absorbs little moisture from the atmosphere. Since its surface is, therefore, relatively dry it is very suitable for admixture into single powder developers under normal conditions of temperature and humidity.
• protectants which may be satisfactorily employed in single powder developers containing lithium hydroxide include boric anhydride, metaboric acid, phthalic anhydride, chlor phthalic anhydride, sodium and potassium' bisulfites and metabisulfites. These protectants may be employed singularly and in various mixtures. Certain mixtures of the protectants have been found'advantageous for use in single powder developers containing certain alkali components.
• This example illustrates the uses of lithium hydroxide monohydrate in a single powder mixture as' an addend to increase activity by increasing the alkalinity of the formula.
• This single powder mixture did not discolor or otherwise deteriorate when incubated at F. for
• lithium hydroxide monohydrate having slightly more than the theoretical amount of water of ciystallization (56.2% lithium hydroxide, 43.8% water) or slightly less than the theoretical amount (58.0% lithium hydroxide, 42.0% water) did cause discoloration when stored under the same conditions.
• the lithium hydroxide having the optimum amount of water of crystallization was also employed in the following examples.
• lithium hydroxide in the formula did not affect the stability of the powders which remained free of discoloration on storage.
• the sodium metaborate used in the above formula was prepared by drying the tetrahydrate. form ofthe compoundby heating it, after previously having treated it with carbon dioxide gas. This treatment increases the stability of the compound in that it inhibits the discoloration reaction that would normally occur if the tetrahydrate
• the use of lithium hydroxide in the formula. did: not affect the stability of the powders which remained free of discoloration on storage.
• the sodium metaborate-boric anhydride blend. was prepared. by heating the mixture for 4 hours at 70 C.v This treatment stabilizes the sodium metaborate. in such away as. to make it suitable for use in single powder formulas.
• the sodium metaborate-metaboric acid blend was prepared by heating the mixture for 4 hours at 70 C. This treatment stabilizes the sodium metaborate in such a way as to make it suitable for use in single powder for. mulas.
• example and Examples 2 and 3 serve to illustrat the use of lithium hydroxide as an addend to single powder formulas to balance the acidic eifect of thevarious combinations of compounds used toprevent discoloration and deterioration of the powders and thus to preserve the photographic properties of the formulas.
• Example 5 Gram Elon 2.0. Hydroquinone 4.0 Sodium sulfite 22.5 Anhydrous sodium tetraborate (finely ground) 14.7 Lithium hydroxide monohydrate 7 .6 Potassium bromide 2.0. Boric anhydride 1.2
• This example serves to illustrate the use of lithium hydroxide as an addendto a single powder. formula to supplement the alkalinity of sodium tetraborate, without affecting the stability of the powders.
• This example serves to illustrate. the use of lithium 'hydroxide in substitution for sodium hydroxide in high energy formulas making it possible to pack the formula. as a single powder.
• This example serves to illustrate the use of lithium hydroxide as an addend to a single powder formula to. supplement the alkalinity of sodium borate without affect! ing the stability of the powders.
• This formula also has the advantage of greater solubility over thatgiven in Eas ample 5 because of the greater ease of. solution of the hydrated form of sodium borate as compared to the anhydrous form.
• compositionsshown in the examples should be dissolved in. water to make one liter of solution.
• Example 8 58.2 grams (0.2 mole) of sodium borate pentahydraite was intimately mixed with 22.4 grams (0.53 mole) of lithium hydroxide monohydrate and the mixture heated;
• Still another method of treating sodium metaborate so that it is compatible in single powder developer mixtures is to stabilize it by washing with a solution of an organic acid in an alcohol.
• Sodium metaborate tetrahydrate can be suitably stabilized by washing in a 5% solution of citric acid in denatured ethyl alcohol so that it can be packed in a single powder developer containing a low concentration of boric anhydride as protectant. Without this treatment, protectant concentrations 5 to 10 times higher are necessary to obtain an equivalent protection against deterioration.
• the preferred procedure of treatment requires that the sodium metaborate tetrahydrate be added to the acidsolvent solution in a ratio of 1000 grams of the metaborate compound to 1 liter of solution. The mixture is stirred thoroughly and the compound filtered off. The compound is then heated mildly to remove absorbed solvent. Best results are obtained when the solvent is anhydrous. It is necessary to remove nearly' all of the absorbed solvent from the treated product to obtain maximum stability.
• the choice of acid and solvent is not limited to any particular group.
• the basic requirements are that the acid be reasonably soluble in the solvent chosen and that the solvent does not excessively dissolve sodium metaborate tetrahydrate. There are, however, some combinations of acid and solvent that are much more effective than others.
• Example 9 Using sodium metaborate tetrahydrate treated with a solution of 5% citric, malic or tricarballylic acid in dc natured ethyl alcohol the following single powder was prepared:
• the powder showed no objectionable discoloration after being stored for one week at F.
• developing agent in the claims is to be interpreted as comprising either one or several separate organic developer compounds.
• a stable single powder photographic developer composition containing a mixture of an organic silver halide developer, lithium hydroxide monohydrate and a stabilizing agent selected from the group consisting of boric anhydride, metaboric acid, phthalic anhydride, chlorphthalic anhydride, sodium bisulfite, potassium bisulfite, sodium metabisulfite and potassium metabisulfite.
• a stable single powder photographic developer composition containing a mixture of an organic silver halide developer, sodium sulfite, sodium carbonate monohydrate, potassium bromide, boric anhydride and lithium hydroxide monohydrate.
• a stable single powder photographic developer composition containing a mixture of an organic silver halide developer, sodium sulfite, sodium metaborate trihydrate, CO2 treated, potassium bromide, boric anhydride, sodium metabisulfite and lithium hydroxide monohydrate.
• a stable single powder photographic developer composition containing a mixture of an organic silver halide developer, sodium sulfite, sodium metaborate tetrahydrate containing 10% metaboric acid, potassium bromide, phthalic anhydride, sodium metabisulfite and lithium hydroxide monohydrate.
• a stable single powder photographic developer composition containing a mixture of an organic silver halide developer, sodium sulfite, anhydrous sodium tetraborate, boric anhydride and lithium hydroxide monohydrate.
• a stable single powder photographic developer composition containing a mixture of an organic silver halide developer, sodium sulfite, boric anhydride and lithium hydroxide monohydrate.
• a stable single powder photographic developer composition containing a mixture of an organic silver halide developer, sodium sulfite, sodium borate pentahydrate, boric anhydride and lithium hydroxide monohydrate.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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Cited By (3)

Citations (6)

• 0
  • BE BE536991D patent/BE536991A/xx unknown
• 1954
  • 1954-04-01 US US420463A patent/US2739894A/en not_active Expired - Lifetime
• 1955
  • 1955-03-23 GB GB8457/55A patent/GB766101A/en not_active Expired
  • 1955-04-01 FR FR1131909D patent/FR1131909A/fr not_active Expired

Patent Citations (6)

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