US3252797A - Simultaneously developing and fixing photographic images - Google Patents

Description

United States Patent 3,252,797 SIMULTANEOUSLY DEVELOPING AND FIXING PHGTOGRAPHIC IMAGES Dave R. Kazen, Niles, Ill., assignor to Chicago Aerial Industries, inc, Barrington, 1111., a corporation of Deliaware No Drawing. Filed Nov. 16, 1961, Ser. No. 152,942 11 Claims. (Cl. 96-61) The invention relates to processes for the developmentof silver images in photographic silver halide emulsion layers which processes utilize the simultaneous development and fixing of photographic images and to the unique compositions of fixing agents.

In the formulation of photographic monobaths, a primary problem arises which has been termed balancing. Balancing may be defined as the adjustment of the concentration and activity of the fixing agents employed relative to the concentration and activity of the developing agents. If solution balance is correct, the developing agent is able to initiate development of latent image centers before fixation proceeds to any appreciable extent. If balance is incorrect and too high a concentration of fixing agent is employed, the development of the latent image centers is prevented; because they are destroyed by the fixing process prior to development. This destruction of the latent image centers by fixing, results in a serious loss of speed of the photographic emulsion being processed. Furthermore, when the exposure has been increased to compensate for such a loss of effective emulsion speed, a fixing agent which acts too rapidly reduces the contrast of the images formed with the result that negatives produced in such a bath are not usually considered desirable for photographic printing.

As a result of the exacting requirement due to the balancing problem associated with monobath processes, there exists a need for a class of slower fixing rate reagents that would not suffer from low capacity or low efficiency and at the same time would prove adaptable in processing at various temperatures with known and controllable rates. Monobath processing solutions have not been used extensively for this requirement, and as the name suggests, monobath photographic processing solutions combine the developing and fixing solutions into a single solution.

The fixing agent compounds which I have found most acceptable in my efforts to overcome the balancing problem consists of chemical combinations of water soluble amines, such as the aliphatic amines and derivatives thereof, and an inorganic compound containing an anion sulfite group. It has been found that the mixture of such compounds unexpectedly combine to produce a chemical synergistic fixing effect that neither compound is capable of performing separately.

In order to corroborate the relative poor solubility of silver bromide in either the water soluble aliphatic amines or sulfur containing anion group compounds and of the solubility of silver bromide in conventional fixing agents, one may refer to the classic work by Seidell, entitled Solubilities of Inorganic and Metal Organic Compounds, fourth edition (1958). Seidell lists the solubility of silver bromide in solutions of certain reagents under optimum conditions as follows:

Since the total solubility of silver halide in a fixing solution determines the maximum capacity of that solution to dissolve the silver halide, it would appear from the foregoing table that in comparision with the conventional fixing agents, the listed aliphatic amine and sodium sulfite would normally prove unacceptable. However, a fixing bath com-prised of 20% by weight ethylamine and 20% by Weight sodium sulfite performs far beyond expectations as a solvent for silver bromide. In fact, it has been found that 0.92 mole per litter of silver bromide may be placed in solution in such a bath. While this solubility generally indicates the usefulness of applicants novel fixing agent composition, other considerations such as rate of fixation, the solubility and stability in water of the silver complexes formed during fixing, plus other factors determine the practical usefulness of any fixing bath.

In addition to the novel synergistic fixing effect found when combining the aliphatic water soluble amines and/ or its derivatives and an inorganic compound containing an anion group, many additional advantages have become apparent such as high fixing capacity and high efficiency. As previously suggested, these compositions are of a slower fixing rate class than the sodium or ammonium thiosulfate fixing agents commonly employed. However, unlike other fixing agents used in place of the conventional fixing agents, the fixing agents employed in my invention have relatively high capacity and high efficiency. This desirable effect is achieved while at the same time maintaining a controllable rate of fixing and correspondingly less active developers are necessary.

Since there are a number of applicable water soluble aliphatic amine compounds, the combination with the S0 anion compound allows for a wide variation in the pH and ionization constant of the fixing solution. It has been found that large molecule aliphatic amines produce steric hindrance, and are less active than the aliphatic amines of smaller molecular size; i.e., N-(Z-hydroxypropyl)-ethylenediamine is less active than methylam-ine. Hence, a long molecular chain aliphatic amine combined with an organic sulfite, such as sodium sulfite, may be used for fixing at high temperatures, while a shorter chain aliphatic amine combined with the inorganic sulfite may be used for fixing at lower temperatures. With the number of water soluble aliphatic amines applicable, it is possible to chemically create a fixing agent having unique charactertistics in order to overcome the monobath balancing problem.

A principal advantage in the utilization of the combination of the aliphatic amine and an inorganic sulfite is characterized by the extremely high solubility of the formed sliver complexes. Due to the increased solubility of the silver complexes formed with the fixing reagents utilized in the present invention substantially reduced sludging is encountered in the fixing baths which in turn results in a considerable reduction of the maintenance requirement of the bath. Reduced sludging of the process solution is especially important in the continuous monobath printing contact processes and in the diffusion transfer processes where it has hitherto not been possible to put large amounts of fixer in the solution and still accomplish the desired results.

Another advantage realized in the utilization of the invention is that chemical sulfur staining agents are not formed during the fixing reaction. In addition, the presence of an inorganic acid sulfite compound in the fixing agents, such as sodium bisulfite or potassium metabisulfite, will act to prevent oxidation of the developing solution in the emulsion layer just as they would in an.

acid fixing bath even though the inventive fixing bath solutions are generally strongly basic.

chemically combines as a fixer-preservative.

The monobath compositions of the present invention can attain both higher densities and higher gammas than heretofore possible in monobath formulas containing thiocyanates or thiosulfates as fixing agents. For example, certain compositions of the inventive monobath formulas have produced densities in excess of four and gammas in excess of two and one-half. In fact, the inventive monobath compositions, unlike those of the prior art, have achieved gamma infinity processing in all of experimental emulsions. Futhermore, attainment of these high densities and gammas by the inventive monobath compositions have not concomitantly resulted in a higher fog level or increased processing time.

By way of example of the improvement in gamma and density activity that may be achieved using an inventive monobath composition, a comparison which shows the improvement which may be effected is the comparison between the first formula given by way of example in the Goldhammer Patent No. 2,901,350, and the first example in the present application.

The reference formula in the Goldhammer patent employs sodium thiocyanate and sodium thiosulfate (anhydrous) as the fixing agents and ethylene diamine as the alkali constituents. The solution contains a total of 13.3 grams of developing agent per liter with a total salt content of 120 grams per liter. This bath gives a gamma of 0.56 on medium speed panchromatic film in a processing time of 7 minutes at 68 F. The bath prepared in accordance with the present invention using ethylene diamine and sodium bisulfite as both the alkali constituent and the fixing agent and utilizing the same proportions and amounts of the same developingagents, has a salt content of only 50 grams per liter and gives with the same film, a gamma of 0.95 and a density range of 2.30 in a processing time of 7 minutes at 68 F. Since the two baths differ only in the combination of chemicals used as alkali and fixing agent and in the resulting salt content and pH, the comparative results show how use of the inventive fixing agents in a bath otherwise identical to Goldhammers results in higher gamma and higher density in a comparable time.

Monobath formulations utilizing the present invention consists primarily of a combination fixer-preservative and a developer constituent. The combination of an aliphatic amine and an inorganic sulfite compound The invention relates primarily to the novel composition of a fixer-preservative which utilizes as an aliphatic amine,

singularly or in combination with other aliphatic amines or homologues thereof to produce a strongly basic soluv tion in combination with an inorganic sulfite compound. The inorganic sulfite compound can be either an alkali metal or alkaline earth, such as sodium or calcium.

In general, the following typical primary, secondary, and tertiary aliphatic amines which are water soluble and are more strongly basic are applicable providing there are no detrimental side reactions: methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, n-propylamine, di-n-propylamine, tri-n-propylamine, n-butylamine, n-amylamine, n-hexylaminc, laurylamine, ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, ethanolamine, diethanolamine, triethanolamine and allylamine.

The aromatic amines, typified by aniline, are much weaker bases and are not generally useful.

These aliphatic amines are highly desirable so long as there is no appreciable side reaction, such .as precipitation or reduction in the level of development activity. Generally speaking, the higher the ionization constant of the aliphatic amine employed the faster the clearing time of the bath.

While most of the examples given employ phenidone (1 phenyl-3-methyl-5 pyrazolidone) as a developer in conjunction with hydroquinone as a density building agent,

it should be understood that the present invention is not limited to this class of developing agents. Many of the active developing agents such as pyrogallol, Metol (monomethyl para-aminophenol sulfate), Amidol (diaminophenol hydrochloride), etc., will also produce useful results,

The following examples illustrate typical monobath formulas:

Example 1 A formula for high contrast processing of medium speed panchromatic film:

Water (90 F.) ml 750 Sodium bisulfite gr Amidol gr 10 Hydroquinone gr 3.3 99.1% ethylene diamine -ml 53.5 0.5% 6-nitrobenzimidazole ml 40 Water to make 1.0 liter. pH:10.75. Gamma=0.95. Time=10 minutes at 68 F. Density range:2.3 on medium speed panchromatic film.

Example 2 A typical formula for use with medium speed aerial film and well adapted for use in saturated web monobath processing systems at different ambient temperatures is characterized by the following composition:

Water (90 F.) ml 750 Sodium sulfite gr 37 Phenidone gr 4 Hydroquinone gr 14 Monoethanolamine ml 80 M rcapto succinic acid gr 13 Water to make 1.0 liter. pI-I:11.3.

Gamma F. Clearing Time 1. 2 9 minutes. 1. 4 4.5 minutes. 1.6 2minutes. 2. 0 1 minute. 2. 5 45 seconds.

Example 3 A typical formula for conventional negative movie film is characterized by the following composition:

Water (90 F.) m1 750 Triethanolamine ml 60 Sodium sulfite gr 20 Sodium bisulfite gr 20 Amidol gr 10 Thiomallic acid gr 5 Water to make 1.0 liter. pH=8.4. Gamma=0.7. Time=8 minutes at 75 F. (constant agitation),

Example 4 A rapid processing formula for microfilm adapted for use at a variety of ambient temperature levels is characterized as follows:

Water (90 F.) '1 750 Sodium sulfite gr 37 Hydroquinone gr 14 Phenidone gr 4 Monoethanolamine ml 80 Mercapto succinic acid gr 15 Water to make 1.0 liter. pH=11.3.

A formula for high temperature use in substitution of the composition suggested in Example 2:

Water (90 F.) mL- 750 Sodium sulfite gr 37 Hydroquinone gr l4 Phenidone gr '4 Monoethanolamine ml 80 Sodium sulfate gr 100 Thiomallic acid gr 13 Water to make 1.0 liter.

Time=3 minutes at 90 F. Gamma=1.6 on medium speed aerial film.

Example 6 A formula for the same purpose as formula Number 2 but using Meto-l (monomethyl para-aminophenol sulfate) in place of .phenidonc (1 pheny1-3 methyl-S-pyrazolidone):

Water (90 F.) ml 750 Sodium sulfite gr 37 Metol (monomethyl para-aminophenol sulfate) gr 5 Hydroquinone gr 14 Monoethanolamine ml 80 Thiomallic acid gr Water to make 1.0 liter.

Time:5 minutes at 70 F. Gamma=1.5 on medium speed aerial film.

Example 7 A high contrast formula for alternate use with Example 3 in processing negative movie film is characterized by the following composition:

Water (90 F.) ml 750 Sodium sulfite gr 37 Hydroquinone gr 14 Phenidone (l phenyl-3-trnethyl-5-pyrazolidone) gr 4 Monolene N-(2-hydnoxypnopyl)ethylencdiamine gr 100 Thionuanol ml 12.5 Water to make 1000 cc. pH: 10.8.

Time=4 minutes at 70 F. Gamma=0.93 on negative movie film.

Example 8 A formula in substitution of Example 4 for low temperature processing of microfilm and using pyrogallol as a developing agent in place of hydroquin one is characterized by the following composition:

Water (90 F.) ml" 750 70% ethylamine ml 50 Thiomallic acid gr 10 Sodium sulfite gr 37 Pyrogallol gr 14 Phenidone gr 4 Potassium hydroxide gr 16 Water to make 1.0 liter.

Time=2 minutes at 65 F. Gamma=2.05 on microfilm.

As pointed out hereinabove, the silver complexes when formed in combination with the inventive fixing agents have high solubilities and the use of these agents are especially adaptable in diffusion transfer processes where sludging of the bath is frequently encountered. A formula using a specific inventive fixing agent composition in a diffusion transfer bath which has an inherently low sludging potential is characterized by the following composition:

Example 9 Water (90 F.) ..-ml.. 750 Sodium sulfite gr 75 Hydroquinone gr 15 Phenidone (1 phenyl-3 methyl-S-py-razolidone) gr 1 Sodium bisulfite gr 5 Monoethanolamine ml Potassium bromide gr 1.5 Water to make 1.0 liter.

Since the majority of the amines are liquids or solutions of amines in water and/ or alcohol, it has been found that the concentration excluding water of any of the above formulas may be mixed together in the proportions stated or in the ratio of proportions stated to form highly concentrated mixtures having a high storage density. In addition to the high storage density achieved, these mixtures have been found to have excellent keeping qualities as long as they are kept in airtight containers. Combined developing and fixing baths, diffusion transfer baths or fixers can then be prepared conveniently as needed by dissolving the appropriate mixture in an appropriate volume of water.

A fine grain dilutable monobat-h formula using the inventive fixing agents and ideally suited for use with any type of thin film emulsion is characterized as follows:

Water F.) ml 500 Catechol gr 62 70% ethylamine ml 200 Sodium sulfite gr 31 Potasiurn bromide gr 62 Water to make 1.0 liter.

The above formula has proven useful when diluted with water in proportions varying from A to part of the concentrate with the only diiference between the dilution ratios being clearing time. The dilution ratios currently of maximum utility and hence preferred are:

Fi lrn- Dilution Slow speed (thin) 31 parts water to l pant concentrate.

Medium speed (thin) 23 parts water to 1 pant concentrate.

High speed (thin) 16 parts Water to 1 part concentrate.

When subjecting the film to processing at these dilution ratios at 68 F. in the time range from about 20-30 minutes with constant agitation, the gamma will vary between 0.5 and 0.9 depending on the type of emulsion.

While the foregoing examples employing the inventive fixing agents are presently preferred for the specific uses set forth, it has been found that these fixing agents may, in certain instances be employed over a very wide range of proportions of their ingredients and of concentrations of the fixing compound in the final working solution. Experimentally, it has been found that the proportion of the aliphatic amine compound to inorganic sulfite compound may vary between the ratios of 90:1 and 1:20 in Water solutions in which the inventive fixing agents concentration varies between 75% and 0.1%. While the above limits on concentration and ingredient proportions have been experimentally verified, it has been found that the preferred proportions of the aliphatic amine compound to inorganic sulfite compound vary between 15:1

and 1:3 dependent on emulsion and developer characteristics. The entire above set forth range of concentrations of the inventive fixing agents may vary in use depending primarily on film emulsion characteristics and particularly film thickness.

It is apparent that many widely different embodiments of this invention may be made without departing from the spirit and scope thereof, andtherefore, it is not intended (that the invention be limited except as indicated the appended claims.

What is claimed is:

1. A monobath silver halide developing and fixing solution containing a silver halide developing composition and a silver halide fixing solution wherein the fixing agent consists of a water soluble aliphatic amine and an alkali metal salt of sulphurous acid.

2. A monobath silver halide developing and fixing solution containing a silver halide developing composition and a silver halide fixing solution wherein the fixing agent consists of a water soluble aliphatic amine, an alkali metal salt of sulphurous acid and the pH of said solution being greater than 7.

3. A silver halide fixing solution for fixing a silver halide emulsion wherein the fixing agent consists of the combination of a water soluble aliphatic amine and an alkali metal inorganic sulfite wherein said solution shall be of an alkaline composition.

4. A silver halide fixing solution for fixing a developed silver halide emulsion wherein the fixing agent consists of substantially equal parts by weight of a water soluble aliphatic amine and an alkali metal sulfite and said solution shall have a pH greater than 7.

5. A silver halide fixing solution for fixing a silver halide emulsion consisting of ethylene diamine and sodium bisulfite and said solution shall have an alkaline pH.

6. A monobath silver halide developing and fixing bath containing diaminophenol hydrochloride, hydroquinone, 6-nitrobenzimadazole, a fixing agent consisting of sodium bisulfite and a water soluble amine and the remainder consisting of water to form an alkaline solution.

7. A rapid processing composition for developing and fixing a silver halide emulsion consisting of sodium sulfite, hydroquinone, l-phenyl 3 methyl-S-pyrazolidone,

monoethanolamine, mercapto-succinic acid and the remainder being water to form an alkaline solution.

8. A diffusion transfer bath having a relatively low sludging potential containing a developing composition of hydroquinone and phenidone and a fixing agent consisting of sodium bisulfite and monoethanolamine.

9. A concentrate monobath developing and fixing solution for developing a silver halide film emulsion containing a developing composition of ortho-dihydroxybenzene and a fixing agent consisting of ethylamine and sodium sulfite and said concentrate being subjected to an aqueous dilution depending on the clearing time of the emulsion.

10. A silver halide fixing solution for fixing a silver halide emulsion wherein the fixing agent consists of a Water soluble aliphatic amine compound, an alkali metal sulfite compound, the chemical proportionate rates of said aliphatic amine compound to said inorganic compound may vary between 15 :1 and 1:3 respectively and said final solution shall be alkaline.

11. A monobath silver halide developing and fixing solution containing an organic developing agent in admixture with a fixing agent consisting essentially of a water soluble aliphatic amine and an alkali metal sulfite, the total salt content of said solution being attributable solely to said sulfite.

References Cited by the Examiner UNITED STATES PATENTS 2,875,048 2/1959 Haist 96-61 2,901,350 8/1959 Goldhammer 96-61 FOREIGN PATENTS 571,389 8/1945 Great Britain.

OTHER REFERENCES Photographic Science and Engineering, vol. 5, No. 4, July-August 1961, pp. 198-203.

J. TRAVIS BROWN, Acting Primary Examiner.

HAROLD N. BURSTEIN, Examiner.

W. C. GILLIS, C. E. DAVIS, Assistant Examiners.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,252,797 May 24, 1966 David R. Kazen It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 10, for "litter" read liter line 41, for "organic" read inorganic same column 2, line 52, for "sliver" read silver Signed and sealed this 2nd day of January 1968.

(SEAL) Attest:

EDWARD J. BRENNER Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer

Claims (1)

1. A MONOBATH SILVER HALIDE DEVELOPING AND FIXING SOLUTION CONTAINING A SILVER HALIDE DEVELOPING COMPOSITION AND A SILVER HALIDE FIXING SOLUTION WHEREIN THE FIXING AGENT CONSISTS OF A WATER SOLUBLE ALIPHATIC AMINE AND AN ALKALI METAL SALT OF SULPHUROUS ACID.