Odorless photographic bleach-fixing composition and method of use

#This invention relates in general to photography. More particularly, it relates to a photographic bleach-fixing composition, and to a method of processing color photographic silver halide elements using that composition.

#The basic image-forming process of color silver halide photography comprises the exposure of a silver halide color photographic recording material to actinic radiation (such as light) and the manifestation of a useful image by wet chemical processing of the material. The fundamental steps of this wet processing include color development to reduce silver halide to silver and to produce dye images in exposed areas of the material. During or after bleaching to oxidize metallic silver to silver(I), the silver ion is generally removed by dissolving it in a silver solvent, commonly known as a fixing agent.

#In some photochemical processes, bleaching and fixing are combined in a bleach-fixing step using a composition that includes both a bleaching agent to oxidize metallic silver and a fixing agent to dissolve the remaining silver ion, as described for example in U.S. Pat. No. 4,033,771 (Borton et al.).

#Stabilized Photographic Bleach-Fixing Compositions

#Two photographic bleach-fixing compositions of this invention were formulated as shown in TABLE II below. Both compositions were odorless.

#The Example 2 composition was evaluated for storage stability for over five weeks. The aqueous composition was stored in an open glass container at room temperature. Any decrease in volume from evaporation was compensated for by periodically adding deionized water. The composition was analyzed after 5 weeks for the amounts of remaining thiosulfate, sulfite ion, and ferric ions. The results are shown in TABLE III below. They indicate that the bleach-fixing compositions of this invention have storage stability. 2 TABLE II EXAMPLE 1 EXAMPLE 2 COMPONENT (mol/l) (mol/l) 1,3-Diaminopropane- 0.262 0 tetraacetic acid Succinic acid 0.217 0 Ferric nitrate, 9 hydrate 0.238 0 Ammonium thiosulfate 1.307 0.486 Ammonium sulfite 0.117 0.044 Sodium metabisulfite 0.02 0.105 Potassium hydrogen 0.049 0.17 phthalate EDTA 0 0.013 Ferric ammonium EDTA 0 0.13 pH (adjusted with 3.93 4.5 ammonium hydroxide)