US 2875048 A
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( din-W- COMBINED PHOTOGRAPHIC DEVELOPING AND 1 STABILIZING SOLUTION Grant M. Haist and James R. King, Rochester, N. Y., assignors to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey No Drawing. Application September 30, 1957 Serial No. 686,898
12 Claims. 7 (CI. 9661) This invention relates to processes for the development of silver images in photographic silver halide emulsion layers which processes dispense with the usual fixing and washing steps.
It is well known that developed silver halide emulsion layers containing silver images require the removal or inactivation of the .residual silver halide for the picture to be stable under adverse conditions of light, heat and humidity. For this reason, fixing and washing steps are ordinarily, employed after development to convert the silver halide to a soluble salt which is then washed out of'the emulsion layer. t r A number of processes have been proposed to dispense with the laborious fixing and washing steps. For example, Russell U. S. Patent 2,453,346, granted November 9, 1948, discloses the use of various sulfur compounds in conjunction with metal salts for stabilizing silver prints. Acidic solutions containing the sulfur compounds and metal salts are applied to silver halide emulsion layers following development of the silver image. 'In Dreywood U. S. Patent 2,525,532, granted October 10, 1950, emulsion layers are developed withya Metolhydroquinone developer containing various sulfur compounds. Following development, the emulsions are treated with acid solutions prior to drying. In the Broughton et al. U. S. Patent 2,614,927, granted October 21,1952, emulsions containing certain developing agents are developed with alkaline solutions'followed by inactivation of the residual silver halide'with solutions of sulfur compounds such as thioglycolic acid, thiourea or thiosulfates. i V
' We have discovered that when combinations of certain silverhalide developing agents and sufficient quantities of certain organic sulfur compounds are used in alkaline photographic developer compositions and these compositions are used forcombined developing and stabilizing" silver halide emulsion layers, stable silver images are obtained having low density and good resistance to printout of the residual silver halide in the non-image background areas and having good resistance to fading or toning in the image areas which do not require fixing and washing.
One object of our invention is therefore to provide combined developing and stabilizing solutions. for producing stable silver images. Another object is to provide methods for using the combined developing and stabilizing compositions in producing stable silver images. Other objects of our invention will appear from the following description.
These objects are accomplished by using as combined developing and stabilizing solutions for silver halide emulsion layers, alkaline compositions comprising particular silver halide developing agents and organic sulfur compounds. 7 v
The silver halide developing agents used in our combined developer and stabilizing compositions are either hydroxylamine or 3-pyrazolidone' silver halide developing agents.
2,875,048 Patented Feb. 24, 1959 The 3-pyrazolidone silver halide developing agents have the general structure such asan'alkyl group preferably of 1 to 4 carbon atoms or aryl such as phenyl. l V The following compounds are representative of 3- pyrazolidone silver halide developing agents which are useful in the developercompositions of the invention:
1-phenyl-3-pyraz olidone 1-p-tolyl-3-pyrazolidone 5-phenyl-3-pyrazolidone 5-methyl-3-pyrazolidone 1p-chlorophenyl-3-pyrazolidone 1-phenyl-5-phenyl-3-pyrazolidone l-m-tolyl-3-pyra'zolidone 1-phenyl-5-methyl-3-pyrazolidone l-p-tolyl-5-phenyl-3-pyrazolidone 1-m-tolyl-3-pyrazolidone 1 p-methoxyphenyl-3-pyrazolidone 1-acetamidophenyl-3-pyrazolidone l-phenyl-2-acetyl-4,4-dimethyl-3-pyrazolidone 1-phenyl-4,4-dimethyl-3-pyrazolidone 1-m-aminophenyl-4-methyl-4-propyl-3-pyrazolidone 1-o-chlorophenyl-4-methyl-4-ethyl-3-pyrazolidone (17) l-m-acetamidophenyl-4,4-diethyl-3-pyrazolidone (18) 1 p(fl-hydroxyethylphenyl)-4,4-dimethyl-3-pyrazolidone 19) 1-p-hydroxyphenyl-4,4-dimethyl-3-pyrazolidone (20) 1-p-methoxyphenyl-4,4-diethyl-3-pyrazolidone (21) l-p-tolyl-4,4-dimethyl-3-pyrazolidone (22) l-(7-hydroxy-2-naphthyl)-4-methyl-4-n-propyl-3-pyrazolidone (23.) 1-p-diphenyl-4,4-dimethyl-3-pyrazolidone (24) l-p-(fl-hydroxyethylphenyl)-3-pyrazolidone (25) 1-o-tolyl-3-pyrazolidone (26) 1-o-tolyl-4,4-dimethyl-3-pyrazolidone nocn cn wmcmsn thioglycol HOCH CH SH, fi-mercaptoethylamine H NCH CH SH N,N-diethyl-fl-mercaptoethylamine ZHoQN H-ZCHZ and 2-thiobarbituric acid HNCSNHC OCHr O The following examples illustrate the combined developing and stabilizing solutions and their use for obtaining stable silver images.
This formula is generally useful for producing stable silver images in emulsion layers of all kinds but has been found to be particularly useful for processing direct revers l P pe s suc a .Kqdag aph A pos e Pape w e ,bt e stab l zin t chn q es h e n t "b en at sat q Th s wheh he emuls on, a re ted w t a so ut on o 't an us h or d and e p ucci ic a d. pri s wer ob ain d. wh h tur ed ye ow o exp u e to u t vi e d ation whe ea t e above formula s Print i h r sh stant a y na fe ed n posu to ultraviolet radiation. In the above formula, the sulfite content may be reduced appreciably if desired, for example, to 12.0 grams per liter and stable prints will still be obtained. Minimum processing times of the order of 30 to 90 seconds at room temperature are satisfactory for the above formula with most emulsions. At elevated temperatures such as 100 the processing time may be reduced appreciably to about;1030'seconds.
EXAMPLE 2 Water to 1.0 liter. pH'=12.9.
' EXAMPLE 3 Grams Hydroxylamine sulfate (95%) 10.0 Sodium sulfite, desiccated 50.0 2-thiobarbituric acid 32.0 Sodium hydroxide 30.0 Water to make 1.0 liter.
This formula may be used for simultaneous develop.- ment and stabilization of Autopositive Paper for about 30 seconds at room temperature. Formulas of this type can also be used in stabilizing print-out images obtained by exposure of high speed print-out papers. For this purpose it may be advantageous to prepare the composition from the following stock solutions:
Solution i a Grams Hydroxylamine sulfate (95%) 20.0 Sodium sulfite, desiccated 100.0
Sodium hydroxide gi-r -fl-u-m-rrt-m-rt-e 13.0 Water to make 1.0 liter.
Solution B V Z-thiobarbituric acid 60.0 39.0
Sodium hydroxide Wa e t tnak li er. 7 12E o aeh solrt qnalz-tt- The twojsolutions-can be mixed for use in the proportions ment carried out for about 30 seconds to 2 minutes depending on the particular emulsion under consideration.
EXAMPLE 4 V Grams Hydwxy amine sul at .-t..---.- -.'-V----V- Sodium sulfite, desiccated 50.0 N,N diethyl-fi-mercaptoethylamine hydrochloride 23.0 'S Q J mZhY Xide V V f Water to make 1.0"liter.
Emulsions can be processed in this composition for about 60 to '90 seconds .at room temperature. When 18- mercaptoethylamine hydrochloride is used in the formula in place of the diethyl vderivative,'the processing time may be reduced.
EXAMPLE 5 1 V Grams Sodium sulfite, desiccated 4.0 1-phenyl-3-pyrazolidone 4.0 ;l-,ascorbic acid 20.0 '2-thiobarbituric acid 32.0 Sodium hydroxide 30.0 Water to make 1-.0 liter.
This composition .was found to be particularly useful "for processing Kodak Autopositive 43 Paper for 1. seconds at room temperature yielding prints exhibiting no discoloration afterl6 0 seconds exposure at 1 foot from a 45-ampere are lamp.
*EXAMPLE 6 S ple of t ormu f Examp 3 er p ep ed in which the concentration of 2-thiobarbituric acid was varied from 2 20, 25 and 32 grams perliter, the pH of each solution being 12.5 adjusted'with dilute NaQH solution. Each formula was used for processing Kodak Autopositive 43 ,Paper for 15, 30 and 60 seconds and the solution then blotted ofi immediately thereafter. The prints obtained'by using the solution containing 2 grams of 2- thiobarbituric acid per liter yielded prints unstable to ultraviolet radiations. At 20 grams per liter, slight printe out was obtained'upon exposure of the prints to ultrayiolet radiation. At 25 and BZgrams per liter, the prints were very stable. Accordingly, it is desirable to use at least about 15 grams per liter of 2-thiobarbituricacid-to obtain reasonably well stabilized prints, the upper limit being dependent in part onthe solubility of the compound .and fon matters of economy.
With the other sulfur compound of the invention the c n en ra ons n-th de e op ng nd ab l z g comp tio s r h .heq the rde .o a e s about 5 to 1 g ams per liter. V V 7 In the manner of theabove examples other compositions may be compounded having hydroxylamine in combination with thioglycol, and the 3-pyrazolidone compounds in combination with thioglycol, the fi-mercaptothy am ne and 2-thio rb hti acidn he aboxeexa p es. the c mbin d de e ope -s bilizi ol ti n w compou d so a t h mo t ective with particular photographic elements such as Autopositive paper. :Some adjustments in ratio of developing agent to s fu comp und and pH ay be necessary w e usin the compositions for processing otheremulsions. These compo tions .can e applied ,by a y f t e con e t seine su h a immersion. ,sp. a .a p .ication, surf pl sza n and e ke Ihe following experiments were carriedout to demonstrate the improved results obtainable with the composi. tions ofthe invention compared to similar "formulascom edeve op g a nt and ulfur EXAMPLE 7 Solution 1 The developer composition of Example 1.
Solution 2 Same as Solution 1 but containing the same amount of thiourea in place of thioglycerol.
Water to 1 liter;
When the above formulas were used for developing an exposed emulsion layer at room temperature, only the first solution containing 1 -phenyl-3-pyrazolidone and silver images. In addition,formulas 3, 4 and 5, all containing hypo, were particularly objectionable since they readily precipitated silver from solution especially when used at elevated temperatures which condition was apparent'after minutes at 100 F. Solution 1 showed no tendency to precipitate silver at temperatures ranging from room temperature to 180 F. and pH ranges of from 8 to 13. Also, Solutions 3 and 4 produced mottled prints with a Kodagraph Autopositive Paper. Furthermore, Solution 5 produced prints which faded out completely upon storage under adverse conditions of heat and humidity.
EXAMPLE 8 Grams Hydroquinone V 5.5 Sodium sulfite, desiccated 50.0
Sodium carbonate monohydrate 50.0 Water to 1 liter.
Upon addition of 32 grams per liter of thiobarbituric acid to this developer formula at pH 10.4 and use of the composition for developing samples of Autopositive Paper, it was found that development was completely repressed, no sign of image being obtained even after 5 minutes of treatment.
EXAMPLE 9 The effectiveness of thiobarbituric acid and potassium iodide as stabilizing agents was compared by adding 32 thioglycerol yieldedprints having ultraviolet light stable grams of each per liter of the developing composition of Example 3, the pH being adjusted to 12.5 in each case. Samples of a photographic paper were developed for 15, 30 and 60 seconds in each formula, then blotted and dried. The baths containing thiobarbituric acid gave black images on a white background and the other baths containing potassium iodide gave very weak images on a yellow background.
What we claim is:
l. A photographic developer composition comprising an aqueous alkaline solution of 1) a member of the class consisting of hydroxylamine and a 3-pyrazolidone silver halide developing agent and (2) a member of the class consisting of monothioglycerol, thioglycol, [St-mercaptoethylamine, N,N-diethyl-,H-mercaptoethylamine and 2-thiobarbituric acid.
2. A photographic developer composition comprising an aqeous alkaline solution of 1-phenyl-3-pyrazolidone and monothioglycerol.
3. A photographic developer composition comprising an aqueous alkaline solution of l-phenyl-3-pyrazolidone and 2-thiobarbituric acid.
4. A photographic developer composition comprising an aqueous alkaline solution of hydroxylamine and 2- thiobarbituric acid.
5. A photographic developer composition comprising an aqueous alkaline solution of hydroxylamine and a fi-mercaptoethylamine.
6. A photographic developer composition comprising an aqueous alkaline solution of hydroxylamine and monothioglycerol.
7. A process for producing a stable photographic silver image which comprises treating an exposed silver halide emulsion layer with an alkaline solution containing (1) a compound of the class consisting of hydroxylamine and a 3-pyrazolidone silver halide developing agent, and (2) a compound of the class consisting of monothioglycerol, thioglycol, S-mercaptoethylamine, N, -diethy1-fl-mercaptoethylamine and Z-thiobarbituric acid.
8. A process for producing a stable photographic silver image which comprises treating an exposed silver halide emulsion layer with an alkaline solution containing l-phenyl-B-pyrazolidone and monothioglycerol.
9. A process for producing a stable photographic silver image which comprises treating an exposed silver halide emulsion layer with an alkaline solution containing 1- phenyl-3-pyrazolidone and Z-thiobarbituric acid.
10. A process for producing a stable photographic silver image which comprises treating an exposed silver halide emulsion layer with an alkaline solution containing hydroxylamine and 2-thiobarbitu1'ic acid.
11. A process for producing a stable photographic silver image which comprises treating an exposed silver halide emulsion layer with an alkaline solution contain-. ing hydroxylamine and monothioglycerol.
12. A process for producing a stable photographic silver image which comprises treating an exposed silver halide emulsion layer with an alkaline solution containing hydroxylamine and a B-mercaptoethylamine.
References Cited in the file of this patent UNITED STATES PATENTS 2,432,506 Chilton et a1. Dec. 16, 1947 2,453,346 Russell Nov. 9, 1948 2,688,548 Reynolds Sept. 7, 1954