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 relatesto single powder photographic developers, and more pa1"tiiiularly" to single owder developers containing stabilizing materials which impart improved stabilityto the single powder developer at relatively high temperatures.
• Single powder developer mixtures may contain anorganic developer component or mixtures of such components including monomethylparaminophenol sulfate (Elon or motel), hydroquinone, p-ammophenolhydrochloride; -aminophenol sulfate, pyrogallol,w parahydroxyphenyl glycine, catechol, diaminophenol hydrochloride,
• monomethylparaminophenol sulfate Elon or motel
• hydroquinone p-ammophenolhydrochloride
• -aminophenol sulfate pyrogallol,w parahydroxyphenyl glycine
• catechol diaminophenol hydrochloride
• the alkali com'- ponent may be'the stable hydrate of an alkali carbonate, a desiccated alkali carbonate, an alkali metaboratc, or an alkali sulfit'ei Generally the stable alkali carbonate monohydrate is preierred.
• the oxidation. preventing component may be an alkali sulfite, and the anti-fogging component maybe potassiumbromidev or iodide.
• Stabilizing components for such a single powder developer include maleic an+ hydride, salicylic acid; alkali metabisul'fite, benzoic anhydride, orthoben zoic sulfimide phthalimide, and phthalic anhydride.
• the latter has outstanding stabilizing properties in the presencev ofeither sodium carbonate or borax and has been employed considerably more than the other stabilizers mentioned in that patent.
• Phthalic anhydride-l ras been employed most successfully in developer compositions having. as the alkali component either sodium carbonate or sodium sulfite, or mixtures thereoti Less success has been attained in the case of the important class of developers containing sodium metaborate as an alkali ingredient, possibly the greatest disadvantage of employing phtl'ialic anhydride in single powder developer' 'miXtures,
• phthalic anhydr-ide when used alone in suf- .lficient amounts for stabilizin purposes, may react due in part to temperature effects with these basic substances and form gas under sufiflcient pressure to distend the hermetically sealed can in which the developer powder ispackaged, and
• Boric anhydride does netnave the disadvantages peculiar to: pnthalic anhydride. It ap ears that boric anhydrlde being muchless acid than phthalic anhydride does not react as easily as phthali'c anhydrid'e with alkali carbonates or alkali sul-fites such as sodium carbonate and sodium sulfite. In this respect it is noted that the pilot the phthalic acid derived from phth'alic anhydride is about while the pH of boric acid derived from bone anhydride is about 5.4 at 31% concentrations. Boric anhydride is admirably suited as a stabilizer and has the characteristics required for a stabilizer. It is acidic, relatively colorless, odorless, and stable and has not use e'terious action photographically.v
• Boric anhydri'de is'pa'rticularly suited for use in the single powder photographicdeveloper mix-.- ture of either the stable hydrate of an alkali car.- bona'te or also a desiccated alkali carbonatet
• the I appears to be more stable in the-presence of an organic developer than a eom arable'quantity of the con'espondi'n'g desiccated 'alkali carbonate.
• Another object of the invention is to provide an improved stabilizing agent for single powder developers which will prevent decomposition of the developer at temperatures up to 130 F.
• a further object of the invention is to provide an improved stabilizing agent which makes possible the production of single powder developers having improved stabilizing characteristics 'containing as the alkali ingredient, sodium metaborate.
• Still another object is te -providean improved stabilizing agent for single powder developers which has superior characteristics as respects phthalic anhydride or boric anhydride as stabilizing agents.
• T-he boric anhydride may contain moisture up 0t 35% by weight and Where the term boric anhydride is mentioned in this specification, boric anhydride with a moisture content within this range is meant.
• ingredients of a single powder developer composition may therefore consist of an organic 'developing agent, such as monomethyl paraminophenol sulfate, hydroquinone, p aminophenol hydrochloride, p-aminophenol sulfate, pyrogallol,
• organic 'developing agent such as monomethyl paraminophenol sulfate, hydroquinone, p aminophenol hydrochloride, p-aminophenol sulfate, pyrogallol
• a stable alkali carbonate such as sodium carbonate monohydrate, boric anhydride and a relatively small amount of phthalic' anhydride and may contain the other well known ingredients normally present infla developer, such as sodium sulfite and potassium bromide, the normal and known function of the alkali sulfite being that of preservation, lessening the oxidation in solution of the organic developing agent, while the known function of potassium bromide is that of are'strainer particularly inhibiting fog formar tion in the development of the silver image.
• sample A When packaged in a sealed can and kept for 96 hours at 130 F. sample A was white showing that no reaction or deterioration took place, whereas sample B similarly packaged and heated was discolored. This clearly shows that the phthalic anhydride raises the upper heat resisting range of the mixture.
• Example 2 A B O Grams Grams Grams E1011 2.0 2.0 2.0 Hydroquinone 8. 0 8. 0 8. 0 Sodium sulfite (desiccated) 90. 0 90. 0 90. 0 Sodium carbonate monohydrate 52. 5 52. 5 52. 5 Potassium bromide 5.0 5.0 5.0 Bcric anhydride 1.6 1.6 1.6 Phthalic anhydride 0. 16 0. 08
• samples A and B were white whereas sample C showed slight discoloration.
• samples A and B were white whereas sample C was appreciably discolored.
• sample A was white whereas sample 13 had noticeable discoloration.
• Our inventionthus provides single-p'owderdevelopers which are stable above 125 F. and hence they can be employed in areas in which extreme temperatures are encountered.
• a stable single-powder photographic developer composition containing an organic silver halide developer, 0.5 to 3% by weight of a stabilizing agent comprising boric anhydride having a moisture content not exceeding approximately 35% by weight, 0.05 to 0.3% by weight of a stabilizing agent comprising phthalic anhydride, said mixture of stabilizing agents adapted to prevent decomposition of the developer when exposed to temperatures from 120-130 F. and a soluble stable, and photographically compatible basic ingredient selected from the group consisting of alkali borates, sulfites and carbonates.
• a stable single-powder photographic developer composition containing an organic silver ha lide developer, sodium carbonate monohydrate, 0.5 to 3% by weight of boric anhydride containing less than 35% moisture, and 0.05 to 0.3% by weight of phthalic anhydride, said mixture of stabilizing agents adapted to prevent decomposition of the developer when exposed to temperatures from 120-130 F.
• a stable single-powder photographic developer composition containing an organic silver halide developer, an alkali sulfite, 0.5 to 3% by weight of boric anhydride containing less than G by Weight of moisture, and 0.05 to 0.3% by weight of phthalic anhydride, said mixture of stabilizing agents adaptedto prevent decomposition of the developer when exposed to temperatures from -l30 F.
• a stable singlepowder photographic developer containing an organic silver halide developer, an anhydrous alkali carbonate, an alkali 'sulfite, 0.5 to 3% by weight of boric' anhydride containing less than 35% by weight of free moisture, and 0.05 to 0.3% by weight of phthalic anhydride, said mixture of stabilizing agents adapted to prevent decomposition of the developer when exposed to temperatures from 120- F.
• a stable single powder photographic developer composition containing an organic silver halide developer, desiccated sodium sulfite, 0.5 to 3% by weight of boric anhydride con,- taining less than 35% by weight of moisture, and 0.05 to 0.3% by weight of phthalic anhydride, said mixture of stabilizing agents adapted to prevent decomposition of the developer when exposed to temperatures from'120-13'0 F.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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Citations (2)

• 0
  • BE BE521002D patent/BE521002A/xx unknown
• 1952
  • 1952-06-26 US US295833A patent/US2666702A/en not_active Expired - Lifetime
• 1953
  • 1953-06-26 GB GB17751/53A patent/GB729862A/en not_active Expired
  • 1953-06-26 FR FR1098530D patent/FR1098530A/fr not_active Expired

Patent Citations (2)

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