Photographic element containing scavenger for oxidized developing agent

A photographic element is described which comprises a compound capable of scavenging oxidized developing agent to prevent stain and fog formation in developed color images.

The following examples further illustrate this invention. 
EXAMPLE 1 
Compounds of the invention were evaluated in a two layer format (imaging 
layer and overcoat). The imaging layer was coated on a cellulose acetate 
support and consisted of 1.5 g/m.sup.2 gelatin, 1.1 g/m.sup.2 of image 
Coupler A, 1.75 g per Ag mole of tetraazaindene compound 
(4-hydroxy-6-methyl-1,3,3a,7 tetraazaindene), 0.75 g/m.sup.2 of silver 
halide emulsion and a compound of this invention in the amount indicated 
in Table I. Each emulsion was comprised of silver bromoiodide grains (2% 
iodide; 0.53 micron) which were given sensitized with Dyes B and C noted 
below. The overcoat consisted of 2.0 g/m.sup.2 of gelatin. The coatings 
were hardened with bis(vinylsulfonylmethyl)ether at a level of 1.75% of 
the total gelatin. Saponin was used as a surfactant in both layers. The 
compounds were dispersed at a 1:2 ratio in N,N-diethyldecanamide using 
cyclohexanone (1:3 ratio) as auxillary solvent. The dispersions were 
washed for 6 hours prior to coating. 
Portions of the coatings were placed in a bomb containing air at 4000 psi 
(27,580 Pa) and 50.degree. C., and held for 6, 40, and 72 hours. The 
strips were then extracted to determine the amount of compound still 
remaining. 
Stability results were as follows: 
TABLE I 
______________________________________ 
Percent Compound 
Invention Compound No. 
Remaining 
mg/m.sup.2 
6 hours 40 hours 
72 hours 
______________________________________ 
1 240 100% 93% 87% 
2 76 95% 84% 79% 
Coupler A 
##STR8## 
______________________________________ 
SENSITIZING DYE B 
Anhydro-5,5',6,6'-tetrachloro-1,1',3-triethyl-3'-(3-sulfobutyl) 
benzimidazolocarbocyanine hydroxide 
##STR9## 
SENSITIZING DYE C 
Anhydro 5,5'-dichloro-9-ethyl-3,3'-di(3-sulfopropyl)oxacarbocyanine 
hydroxide, sodium salt 
##STR10## 
From the above data it can be seen that compounds of this invention are 
stable under the conditions of the test and that decomposition is avoided. 
Decomposition results in stain formation in the imaging layers. 
EXAMPLE 2 
Additional tests were run using coatings prepared as described in Example 
1. The purpose of these tests was to show the effects of compounds of this 
invention on dye density values. 
Each example was exposed using a 21 step tablet ranging from 0 to 3.0 
density in steps of 0.15 with a 5500K illuminant for 0.02 sec. through a 
Wratten 8 filter. 
The compounds tested were coated at two levels, 0.17 mmol/m.sup.2 and 0.2 
mmol/m.sup.2, which levels correspond to 10 and 25 mol % of the amount of 
coupler coated. Results from the higher coating level are reported in 
Table II. 
TABLE II 
______________________________________ 
Decrease in Density 
Compound Stain Increase 
No (Step 7) (Toe) (Step 15) 
Blue Green 
______________________________________ 
Control 
(None) 0 0 0 0 0 0 
A (1) .00 .02 .00 .05 .00 .00 
B (2) .03 .04 .04 .30 .02 .02 
13 .08 .17 .41 .61 .04 .03 
3 .08 .14 .19 .42 .04 .03 
1 .19 .34 .23 .64 .04 .02 
21 .17 .27 .17 .40 .04 .03 
22 .18 .24 .24 .46 .04 .03 
23 .14 .17 .21 .33 .03 .02 
24 .14 .20 .24 .41 .04 .04 
25 .15 .21 .32 .66 .04 .03 
27 .12 .13 .14 .43 .04 .03 
38 .20 .28 .44 .80 .04 .03 
39 .16 .32 .22 .48 .06 .03 
______________________________________ 
(1) Compound A is Compound 4 of column 7 of U.S. Pat. No. 4,224,401 
(2) Compound B is Compound 5 of column 7 of U.S. Pat. No. 4,224,401 
As can be seen from the above data compounds if this invention, even when 
coated at 0.42 mmol/m.sup.2, cause minimal blue or green stain, whereas 
the compounds of the prior art either failed to perform or performed at a 
substandard level. 
This invention has been described in detail with particular reference to 
preferred embodiments thereof, but it will be understood that variations 
and modifications can be effected within the spirit and scope of the 
invention.