US 3809563 A
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"United States Patent 015cc 3,809,563 Patented May 7, 1974 3,809,563 METHOD FOR PROCESSING LIGHT-SENSITIVE SILVER HALIDE COLOR PHOTOGRAPHIC MATERIALS Takao Nimura and Kunio Jin, Tokyo, and Hajime Komatsu, Odawara, Japan, assignors to Konishiroku Photo Industry Co., Ltd. No Drawing. Filed Mar. 7, 1972, Ser. No. 232,624 Claims priority, application Japan, Sept. 16, 1970,
45/80,51 Int. Cl. G03c 7/16, 5/32 U.S. CI. 9622 6 Claims ABSTRACT OF THE DISCLOSURE In the processing of an exposed silver halide color photographic material with a bleach-fixing solution containing a ferric salt of ethylene diamine tetraacetic acid, quick bleach-fixing can be effected by incorporating the below-mentioned compound in a bath which is employed prior to said bleach-fixing solution of a bleach-fixing bath.
H2N(3-NH( 0 H2) nNHi JNH2 Wherein n is 0 or a positive integer of l to 5. i
This invention relates to a method for processing lightsensitive silver halide color photographic materials, particularly to a process for quick bleaching of developed silver image.
Recently, the demand for quick processing of lightsensitive color photographic materials has come to be extremely strong. In order to satisfy the above demand, there are adopted such means as to unite or partly omit the steps for color development, stopping, fixing, hardening, cleaning, bleaching, stabilization and the like processing of color photographic materials, or to shorten the processing times in the individual steps. Among these steps for processing of color photographic materials, there is a step for bleaching metallic silver formed by the development of photographic materials. This bleaching is ordinarily etfected by use of a bleaching bath containing potassium ferricyanide or a water-soluble ferric salt of ethylenediamine tetraacetic acid (EDTA).
The bleaching bath containing potassium ferricyanide is sufficient in bleaching power, but is undesirably strong in oxidizing power. Accordingly, thiosulfate which is a solvent for silver halide cannot be incorporated into the bath, and thus a fixing bath should necessarily be used separately to bring about a disadvantage particularly in the case of quick processing.
In case the bleaching bath containing a water-soluble ferric salt of EDTA is used, thiosulfate can be incorporated into the bath, and thus the bleaching and fixing of photographic material can be effected in one bath. However, the said bath has such drawback that is is weak in bleaching power and requires a long processing time, and the actual state is such that in case developed silver formed by use of such a black-and-white developer as used in the case of reversal color development, an ordinary EDTA ferric salt bleaching bath cannot be put into practical use because of its being insutficient in bleaching power.
With an aim to increase the bleaching power, there have been proposed methods using the bleaching bath incorporated with thiourea or its derivative or with a S-membered heterocyclic compound having a mercapto group. However, the former method is disadvantageous in that when the bleaching solution, even in an extremely small amount, is incorporated into a color developer, color fog is formed all over the surface of light-sensitive color photographic material. On the other hand, the latter method is insufficient in efiectiveness and cannot accomplish the object of quick processing.-
Under such circumstances as mentioned above, we have now found that a compound of the general formula Br Br wherein R and R are individually a hydrogen atom, a lower alkyl group, an allyl group (C H or an amino group; and nis 0 or a positive integer of l to 5, displays a markedly excellent bleach-promoting eflect when incorporated into an EDTA ferric salt bleach-fixing solution. The compound of the Formula I forms no such color fog as in the case of thiourea, even when incorporated into a color developer and has a bleach-promoting action equivalent to or more than that of thiourea, even when used in a slight amount, thereby to make it possible to shorten the bleaching time to V; or more. Further, it has been recognized that even when the compound of the Formula -I is incorporated into a bath used prior to the bleach-fixing, such as a stopping, stop-fixing or intermediate bath, the bleach-fixing is complete within an extremely short period of time.
Examples of the compound of the Formula I which is used in the present invention are shown below, but compounds usable in the present invention are not limited to these.
Compound 1 HzN-G S NHNHC S-NH1 Compound 2 H502 /NC 8 NHNHC S-NHz H Compound 3 HaC 0H;
NC SNHNHC SN\ H H Compound 4 H5O:
/NC s NHNHC S-NH: H
Compound 5 H5O: (L5H;
/NC s NHNHC SN\ n H Compound 6 HzN NH; NC s NH(CH2)2NHC S-N Compound 7 HzN-C S NH(CH2)2NHO S -NH Compound 8 mN-o sivmcrmmno s-NH,
Compound 9 Hm-o s NH(CH2)NHC s-Nm The amounts of the above-mentioned compounds to be incorporated into bleaching solutions or into various processing liquids used prior to bleaching are preferably Within the range from 0.02 to 5 g./l. (or maximum soluble amounts thereof). These compounds may be used alone or in the form of a mixture of two or more, or may be used in combination with known bleach-promoting agents.
The present invention is illustrated in detail below with reference to examples.
EXAMPLE 1 A color photographic paper was exposed, subjected to color development (20 C., 10 min.), stop-fixing (20 C., 3 min.) and water-washing (l822 C., 5 min.) and then treated with the following EDTA ferric salt bleachfixing solution (20 C.):
Water to make 1.0 liter.
The times required for bleaching in the above case were as set forth in Table 1.
TABLE 1 Compound Thlo--- Additive Blank urea 1 1 4 9 Amount (g./1.) 1.0 0.02 1.0 0.5 0.5
Time required for bleaching (sec.) 110 60 80 40 45 30 From these results, it is understood that the compounds of the Formula I are more excellent in bleach-promoting action than thiourea.
'EXAMPLE 2 A reversal color film was subjected to the following processings:
(1) First development: 20-1:02 C. (10 min.) (2) First stopping: 20:!:l C. (3 min.)
(3) Water-washing: 20.-' -2 C. (10 min.)
(4) Color development: 20i0.5 C. (9 min.) (5) Second stopping: 20 :1 C. (3 min.)
(6) Water-washing: 20i2 C. min.)
(7) Bleach-fixing: 20 ;1 C. (5 min.)
(8) Water-washing: 20i2 C. min.)
N-methyl-p-aminophenol sulfate g 2 Sodium sulfite g 50 Hydroquinone g 6 Sodium carbonate (monohydrate) .g 45 Potassium bromide g 1 Potassium iodide mg 10 Potassium thiocyanate g 1.5 Water to make 1.0 liter.
First stopping solution:
Glacial acetic acid ml 15 Sodium acetate g 10 Water to make 1.0 liter.
Color developer: G. Sodium sulfite 3 N-ethyl-N-hydroxyethyl-p-phenylenediamine 5 Potassium bromide 1.5 Hydroxylamine sulfate 2.5 Sodium carbonate (monohydrate) 50 Water to make 1.0 liter.
Second sopping solution:
Glacial acetic acid ml 15 Sodium acetate g 10 (Compound 1) g 1.5 Water to make 1.0 liter.
Bleach-fixing solution: G. EDTA ferric salt 50 Sodium carbonate (monohydrate) 3 Ammonium thiosulfate 240 Anhydrous sodium sulfite 10 Wate 2 m ke l-Q liten In case the Compound 1 had not been incorporated into the second stopping solution, the color film was not successfully bleached'even when the bleach-fixing time was prolonged to 20 minutes, whereas in case the Compound 1 had been incorporated into said solution, the film was sufliciently bleached in 5 minutes.
EXAMPLE 3 Example 2 was repeated, except that the second stopping was effected in the same bath as in the first stopping, and the film was washed with water and then treated at 20 C. for 2 minutes with a 0.1% aqueous solution of each of the Compounds 1 to 9, followed by bleach-fixing. In every case, the bleaching was complete within 5 minutes.
EXAMPLE 4 A color photographic paper using a polyethylene laminate paper as the support was exposed and then subjected to the following processings:
Color development: 35 C. (1 min., 30 sec.) Bleach-fixing: 35 C. (1 min., 30 sec.) Water-washing: 3035 C. (2 min.)
Water to make 1.0 liter.
Same as in Example 2.
In case the Compound 3 had not been incorporated into the developer used in the above, the photographic paper was insufiiciently bleached and was turbid in color, whereas in case the Compound 3 had been incorporated into the developer, the photographic paper was completely bleached and a color print could be obtained in such a short time as 5 minutes.
What we claim is:
1. In a method for bleach-fixing an exposed, develop light-sensitive silver halide photographic material with a water-soluble ferric salt of ethylenediamine tetraacetic acid and a fixing agent, the improvement comprising the bleach-fixing being carried out in the presence of a dithiourea compound by processing the photographic material with a bleach-fixing solution or with a bath used prior to the bleach-fixing, the solution or the bath containing therein the dithiourea compound in an amount of from 0.02 g. to 5 g. per liter of bath or solution, the dithiourea compound being represented by the general formula:
wherein n is 0 or a positive integer of 1 to 5.
2. A method according to claim 1 wherein n equals 0. 3. A method according to claim 1 wherein n equals 2. 4. A method according to claim 1 wherein n equals 4. 5. A method according to claim 1 wherein n equals 5., 6. A solution for bleach-fixing an exposed, developed light-sensitive silver halide photographic material comprising water, a water-soluble ferric salt of ethylenediamine tetraacetic acid, a fixing agent and a dithiourea compound, the dithiourea Compound having been incors 5 6 porated in an amount of from 0.02 g. to 5 g. per liter FOREIGN PATENTS of solution and being represented by the general formula: 336,257 3/1959 Switzerland 96 60 BF 5 s Q g RONALD H. SMITH, Primary Examiner wherein n is 0 or a positive integer of 1 to 5. 5 KELLEY, Assistant EXaminel' References Cited US. Cl. X.R.
UNITED STATES PATENTS 62 XR 3,189,462 6/1965 Bard et a1. 96-60 R 3,617,283 11/1971 Ohi et a1 96,-60 BF 3,706,561 12/1972 Mowrey 96-60 R