|Publication number||US3770437 A|
|Publication date||Nov 6, 1973|
|Filing date||Apr 6, 1972|
|Priority date||Apr 6, 1972|
|Also published as||CA1015590A, CA1015590A1, DE2317412A1, DE2317412B2, DE2317412C3|
|Publication number||US 3770437 A, US 3770437A, US-A-3770437, US3770437 A, US3770437A|
|Inventors||Brugger D, Hagenbuch B|
|Original Assignee||Brugger D, Hagenbuch B|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (4), Referenced by (11), Classifications (7)|
|External Links: USPTO, USPTO Assignment, Espacenet|
Unite States Patent [1 1 Brugger et al.
[ Nov. 6, 1973 PHOTOGRAPHIC BLEACH COMPOSITIONS  Inventors: Donald J. Brugger; Barry R.
Hagenbuch, both of 1669 Lake Ave., Rochester, NY. 14650 221 Filed: Apr. 6, 1972 211 Appl. No.: 241,592
 US. Cl 96/60 R, 96/22, 96/59  Int. Cl. G03c 5/32, G036 7/16, G030 5/50  Field of Search 96/60, 60BF, 59,
 References Cited UNITED STATES PATENTS 4/1934 Gaspar 96/21 9/1952 DENSITY Zappert 96/50:
2,611,700 9/1952 Brunncr et al v. 96/60 FOREIGN PATENTS OR APPLICATIONS 580,359 7/1959 Canada 96/60 R Primary Examiner-Norman G. Torchin Assistant ExaminerM. F. Kelley Att0rney-William T. French et al.
[ 7 ABSTRACT The incorporation of bromate ion into photographic bleach compositions which include trivalent iron complexes of aminopolycarboxylic acid as the bleaching agent inhibits the formation of Ieuco cyan dyes when these bleaches are used in the processing of incorpo rated coupler reversal emulsions.
1'2 Claims, 1 Drawing Figure LOG-E PHOTOGRAPIIIC BLEACH COMPOSITIONS This invention relates in general't'o photographic processing and in particular to bleach solutions which include bromate ion.
BACKGROUND OF THE INVENTION:
U. S. Patent Application Ser. No. 228,386 filed Feb. 22, 1972 and entitled Photographic Bleach Compositions describes novel bleach compositions comprising as the bleaching agent a trivalent iron complex of an aminopolycarboxylicacid and halide ion as a silver solvent which hastens conversion of oxidized silver to silver halide thereby facilitating recovery of the silver using electrolytic techniques by making the silver available for complexing with a fixing agent in a subsequent fixing bath which is free of iron. The iron present in" a combined bleach and fix bath apparently hinders the recovery of silver from the spent fixing solution when electrolytic techniques are used.
Bleach baths of the foregoing type are extremely useful and permit exceptionally high yields of recovered vention, the bleach composition includes between about 8 and 30 grams per liter of sodium bromate. The pH of the bleach solution should be maintained between about 2 and 8 preferably between about 4 and 6.5 and ideally at a level of 5 i- .5.
The trivalent iron salts of the following aminopolycarboxylic acids are representative of those useful in the bleach solutions containing iodide or bromide salts,
ethylenediamine tetraacetic acid, ethyliminodipropionic acid, diethylenetriamine pentaacetic acid, ortho-diamine cyclohexane tetraacetic acid,
ethylene glycol bis(aminoethyl ether) tetraacetic acid,
diaminopropanol tetraacetic acid, N-(2-hydroxyethyl)ethylenediam-ine triacetic acid, and the like. I 4 British Pat. No. 1,200,188 may be referred to for additional aminopolycarboxylic acids useful in the process of the invention. The ferric salts'of aminopolycarboxylic acids utilized in the practice of this'invention may silver, however, they do possess one rather significant drawback which may be significant in the machine processing of incorporated coupler reversal products. This drawback is that these bleaching agents tend to form leuco cyandyes in these materials. These leuco dyes can be oxidized back to photographic dyes, however, this procedure requires an extended bleaching treatment of the type which cannot readily be achieved under the stringent limitations of time present in a machine process. I
BRIEF DESCRIPTION OF THE INVENTION:
It has now been discovered that theincorporation of bromate ion as an alkali metal or ammonium bromate salt into bleaches containing ferric complexes of aminopolycarboxylic acids eliminates the problem of leuco dye formation by causing oxidation of the leuco dye to photographic dye'within the time generally required for bleaching.
DETAILEDDESCRIPTION OF THE INVENTION:
from about 50 to about 350 grams per liter of an alkali metal or ammonium bromide or from about 1 upv to about 350 grams per liter of alkali metal or ammonium iodide. As should be obvious, however, mixtures of bromide and iodide salts may also be used to achieve suitable results in the application of these solu-tions to specific incorporated coupler reversal photographic materials. According to the present invention the problem of incipient leuco dye formation which can occur with the use of these bleaches in machine processing or where only brief bleaching periods on the order of less than about three minutes are available can'be eliminated by including in the bleach from about 5 to about 50 grams per liter of alkali metal or ammonium bromate. According to a preferred embodiment of the inbe salts in which all cations are the ferric ion or salts in which one or, more of the carboxyl groups have formed a salt with a cation other than iron, e.g'. with ammonia or'with an alkali metal ion as in an ammonium ferric ethylenediamine tetraacetate or a sodium ferric ethy-' lenediamine tetraacetate. The bleach may also contain a non-chelated salt of an aminopolycarboxylic acid, e.g. the tetra sodium salt of ethylenediamine tetraacetic acid, in addition to the ferric salt.
As is well known, the ferric complexes of these acids are generally supplied inthe form of alkali metal or ammonium salts, e.g. sodium ferric ethylenediamine tetraacetic acid, ammonium ferric ethylenediamine tetraacetic acid, etc. Specifically preferred among these ma terials as the bleaching agent is ammonium ferric ethylenediaminetetraacetic acid which has been found particularly useful in these formulations. I
While the above described silver vbleach solutions comprise the iron salt silver bleaching agents, the iodide or bromide salts and the bromate salts, the bleach formulations ofthe invention may also include other addenda which do not materiallyalter the fundamental silver bleaching and leuco dye conversion activities of the formulations. For example, compounds suchas uncomplexed aminopolycarboxylic acid, sulfites, bisulfites, acids (especially I-IBr) or buffers (especially sodium acetate) (for pH control) etc. may be present. The concentration of the ferric aminopolycarboxylic acid salts should be such that bleaching proceeds relatively fast. About 10-400 grams/liter of the ferric salt are useful. Unexpectedly, beyond about 400 grams/- liter level, the bleaching rate decreases and recovery of silver from the subsequent fixing treatment diminishes substantially. At ferric salt concentrations below about 10 grams bleaching rates are extremely slow.
The bromide or iodide salt may be provided in the form of either the alkali metal or ammonium salt and is used in concentrations of from about 50-350 grams of bromide salt and about 1-350grams of iodide salt per liter.
According to a preferred embodiment of the present invention from about 50 to about 300 grams/liter of bromide or iodide are used. An alternative embodiment which has also been found useful utilizes a bleach which includes from about 50 to about 300 grams/liter bromide salt and from about 1 to about 20 grams/liter of iodide salt.
The bromate may be supplied in any convenient salt form, i.e., as the alkali metal or ammonium salt, however, for reasons of solubility sodium bromate has been found to be a particularly convenient and compatible source of this component.
As is demonstrated below, the pH of the bleach solution can be of critical importance insofar as the stability of the solution is concerned. Thus, although useful bleach solutions can be obtained when the pH is maintained at between about 2.0 and 8.0, it is generally pre-- ferred to maintain the pH of the bleach at about 4 to 6.5. Optimum results are achieved at a pH of 5 i .5. At this last pH the stability of the bromate is increased considerably thereby increasing the useful life of the bleach Atpl-l levels below about 2 uantities of noxious gas are generally produced. At pH levels above about 8,.st b-s antia ly r19, lz si hi spsu s The color processes with which the ferric salt bleaching solutions are used include the well-known reversal subtractivecolor processes wherein multilayer color films and papers having coupler compounds in the emulsion layers are first developed with a black and white developer to form negative silver images in the layers. The film is then generally developed with a pphenylenediamine type of color developer containing a nucleating agent such as an amine borane compound to form positive silver and dye images in the layers. Flash reversal exposure may of course also be used. Thereafter, the bleach solution of the invention is employed to form a silver salt soluble in fixing solution. The film may be washed and/or may not, then fixed with thiosulfate fixing solution. As mentioned above, the silver can be readily recovered from the fixing solution by' electrolytic means. The bleach solutions containing the iron complexes can also be used in processing the color films to color negatives". In'this case, the exposed films are developed only in the color developer followed by the bleach solution of the invention and thiosulfate fixing solution to remove all silver from the film.
The following examples will serve to illustrate the invention.
An incorporated coupler multilayer color film is provided comprising red, green and blue sensiti'vegelatinsilver halide emulsion layers on a support, a yellow filter being coated between the blue and green sensitive emulsion layers. The emulsion layers'contain reactive methylene and phenolic coupler compounds reactive with p-phenylenediamine developing agents to form dyes of colors complementary to the sensitivity of the respective layers. The film is exposed and-processed in sheet or roll form in a roller transport system such as shown in Holley et al, Canadian Pat. No. 862,082 of Jan. 26, 1971 at 85 F using the following steps:
Prehardener-3 minutes p-Toluene sulfinic acid (Na salt) 0.5 g. sulfuric acid (18 N) 5.41 ml. 2,5-dimethoxytetrahydrofuran 4.30 ml. sodium sulfate, anhyd. 147.0 g. sodium bromide, anhyd. 2.0 g. sodium acetate, anh d. 20.0 g. formaldehyde (37.5 27.0 ml. n-methylbenzothiazolium p-toluene aulfonatc 0.04 g water to I liter Neutralizer 1 minute Hydroxylamine sulfate 18.0 g. sodium bromide, anhyd. 17.0 g. glacial acetic acid 10.0 ml. sodium hydroxide 6.8 g. sodium sulfate, anhyd. 50.0 g. water to 1 liter First Developer 7 minutes sodium tetraphosphate 2.0 g. n-methyl-p-aminophenol sulfate 5.0 g. sodium sulfite, anhydrous 39.0'g. hydroquinone 6.0 g. sodium carbonate, monohydrate 24.0 g. potassium bromide 1.5 g sodium thiocyanate 1.32 g 0.1% solution of potassium iodide 9.0 cc water to l liter First Stop 2 minutes sodium hydroxide 1.75 g. acetic acid, glacial 30.0 ml. water to 1 liter Wash 4 minutes Color Developer 15 minutes benzyl alcohol 3.1 cc. sodium tetraphosphate 5.0 g. sodium sulfite, anhydrous 7.6 g. trisodium phosphate 12 B 0 36.0 g. potassium bromide 0.8 g. 0.1% solution of potassium iodide 28.0 cc. sodium hydroxide 2.0 g. 4-arnino-N-ethyl-N-[B-methanesulfonamidoethyll-m-toluidine sesquisulfate monohydrate lO.5 g. ethylenediamine 3.0 g, citrazinic acid 1.35 g. t-butylaminc borane 0.07 g. water to 1 liter Second Stop 2 minutes sodium hydroxide 1.75 g. acetic acid, glacial 30.0 ml. water to 1 liter Wash 3 minutes Bleach 5 minutes potassium ferricyanide 165.0 g. sodium bromide 43.0 g. water to 1 liter pH 8.70 t 0.15 (adjusted with NaOH or H,SO
Fix 6 minutes sodium thiosulfate (anhyd.) 94.5 g. sodium bisulfite (anhyd.) 17.6 g. disodium phosphate (anhyd.) 15.0 g. disodium salt of ethylenediaminetetraacetic acid 0.5 g
water to 1 liter adjust to pH 5.9
Wash 6 minutes Stabilizing Bat-h 1 minute polyoxyethylene ether alcohol (Col. 1 US. Pat. No. 3,369,896) O.l5 ml. formaldehyde (37.5%) 6.0 ml. water to l liter The results of red density measurements performed on the processed film are shown in the FIGURE and described below. 1
treated as described in Example 1 except that the composition of the bleach was as follows:
Ammonium ferric ethylenediamine tetraacetate (58%) 300 ml. Ammonium bromide 300 g. water to 1 liter pH 5.8 6.0 (adjusted with acetic acid) EXAMPLE 3 The method of Example 2 was repeated except that g/l of KBrO was added to the bleach and the pH adjusted to 5i.5. n n The resultsof .red density measurements to show leuco dye formation are shown in the FIGURE and described below.
EXAMPLE 4 The method of Example 2 was repeated except that lOg/l of KBrO were added to the bleachan dThe pH adjusted to 5 i .5.
The results of red density measurements to show the total lack of leuco dye formation are shown in the FIG- URE and described below.
The FIGURE shows the red density of identical incorporated coupler reversal emulsions processed in identical photographic processing solutions except that the composition of bleach was varied as described in Example l-4 above.
The results shown in the FIGURE were obtained using conventional densitometric equipment and techniques.
As can be readily observed from these curves, curves 1 and 4 which represent the standard ferricyanide bleach and the improved aminopolycarboxylic acid, bromide. ion and bromate ion bleach of the present intions can be effected within the spirit and scope of the invention.
1. A photographic bleach composition comprising an aqueous solution of from about 10 to about 400 grams per liter of a trivalent iron complex of an aminopolycarboxylic acid, a member selected from the group consisting of alkali metal and ammonium iodide and vention respectively, are superimposed, thus indicating that no leuco cyan dye was present in the finished image.
Curve 2 which shows the red density of the same emulsion processed in the same fashion as described in Examples 1 and 4 except that a bleach cornprising an aminopolycarboxylic acid and ammonium bromide and having a pH of 6.0 was used, demonstrates substantial red density loss in the D-max region thus indicating the presence of rather substantial amounts of leuco cyan dye.
Curve 3 which shows the red density of an identical color reversal emulsion processed in the same manner as described in Example 2 except that a small amount of potassium bromate was a dded to the bleach shows a minor loss in red density as compared to curves 1 and 4, but a rather substantial improvement in red density as compared to Example g, thus indicating that a reductioniii the amou nt of leuco cyan dye has occurred due to the presence of thebromate ion in the bleach.
The process of the above examples can be carried out so as to produce color negative images in the emulsions by omitting the first developer step and omitting the borane from the color developer. The other ferric complexes of the aminopolycarboxylic acids can be used in the bleach solutions in a similar manner, the bleach solution also preferably being acid if the ammonium ferric complex of the aminopolycarboxylic acids is used.
The invention has been described in detail with particular reference to a preferred embodiment thereof, but it will be understood that variations and modificabromide salts and mixtures of same, and from about 5 toabout 50 grams per liter of alkali metal or ammonium bromate, said solution having a pH of between about 2 and 8.
Y Y 2. The photographic bleach composition of claim 1 wherein the concentration of said salt ranges from about I to about 350 grams per liter when said salt is an iodide salt and from about 5.0 to about 350 grams per liter when said salt is a bromide salt.
3. The composition of claim 2 wherein said trivalent iron complex 'is selected from the group consisting of alkali metal and ammonium ferric complexes of an aminopolycarboxylic acid.
4. The composition of claim 3 wherein said trivalent iron complex is an ammonium ferric ethylenediamine tetraacetate said bromate is sodium bromate and the pH of said composition ranges from about 4 to.about.
.salt is ammonium bromide, said iodide salt is potassium iodide and the pH of said composition is about 5 i .5.
- 6. In a photographic color reproduction process wherein a plurality of superposed differently sensitized silver halide emulsion layers are developed with a p-phenylene-diamine developer to produce silver and dye images in the layers, the silver is bleached to form a silver complex soluble in a fixing solution and the emulsion layers are fixed with a fixing solution, the improvement comprising bleaching the silver with a solution comprising from about 10 to about 400 grams per liter of a trivalent iron complex of an aminopolycarboxylic acid, a member selected ,from the group consisting of alkali metal and ammonium bromide and iodide salts and mixtures of said salts and from about 5 to about 50 grams per liter of a member selected from the group consisting of alkali metal and ammonium bromates, said bleach solution having a pH of between 299! andfi.
7. The process according to claim 6 wherein the concentration of said salt ranges from about l to about 350 grams per liter when said salt is an iodide salt and from about 50 to about 350 grams per liter when saidsalt is a bromide salt.
8. The process according to claim 7 wherein the trivalent iron complex is selected from the group consisting of alkali metal and ammonium ferric complexes of an aminopolycarboxylic acid.
9. The process according to claim 7 wherein the 11. The process according to claim 10 wherein said trivalent iron complex -is an ammonium ferric ethylenediamine tetraacetate said bromate is sodium .brornate and the pH of said bleach solution ranges from about 4 to about 6.5.
12. The process according to claim 11 wherein said bromide salt is ammonium bromide, said iodide salt is potassium iodide and the pH of said bleach solution is about 5 i.5.
* i t t I?
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US1956017 *||Feb 9, 1931||Apr 24, 1934||Bela Gaspar||Method of indirectly producing color photographs|
|US2611699 *||Dec 30, 1949||Sep 23, 1952||Gen Aniline & Film Corp||Regeneration of exhausted silver bleaching solutions|
|US2611700 *||Dec 30, 1949||Sep 23, 1952||Gen Aniline & Film Corp||Regeneration of exhausted silver bleach solutions by means of n-bromo compounds|
|CA580359A *||Jul 28, 1959||Canadian Kodak Co Ltd||Regeneration of photographic silver bleach solutions|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US3839043 *||Apr 20, 1973||Oct 1, 1974||Agfa Gevaert Ag||Process for regenerating spent photographic silver bleaching solutions|
|US3912514 *||May 21, 1973||Oct 14, 1975||Hunt Chem Corp Philip A||Method of regenerating a spent photographic silver bleach solution|
|US3938995 *||Jul 10, 1974||Feb 17, 1976||Eastman Kodak Company||Silver halide color photographic element and process containing leuco dyes|
|US3960565 *||Nov 12, 1973||Jun 1, 1976||Minnesota Mining And Manufacturing Company||Silver bleaching solutions|
|US4040837 *||Dec 2, 1975||Aug 9, 1977||Konishiroku Photo Industry Co., Ltd.||Photographic bleach-fixer|
|US4138257 *||May 2, 1977||Feb 6, 1979||Konishiroku Photo Industry Co., Ltd.||Process for the treatment of photographic materials|
|US4242442 *||Oct 19, 1979||Dec 30, 1980||Fuji Photo Film Co., Ltd.||Method for processing silver halide color photographic material|
|US4294914 *||May 14, 1980||Oct 13, 1981||Eastman Kodak Company||Photographic bleach compositions and methods of photographic processing|
|US4552834 *||Mar 28, 1985||Nov 12, 1985||Eastman Kodak Company||Enhanced bleaching of photographic elements containing silver halide and adsorbed dye|
|US4603100 *||Mar 14, 1985||Jul 29, 1986||Minnesota Mining And Manufacturing Company||Silver image enhancement composition and process for use thereof|
|US4837122 *||Dec 2, 1987||Jun 6, 1989||Mitsubishi Paper Mills. Ltd.||Deleting fluid for printing plates and method for deletion|
|U.S. Classification||430/379, 430/461, 430/383, 430/393|