US3558313A

US3558313A - Water wash for stabilized silver halide photographic materials

Info

Publication number: US3558313A
Application number: US529696A
Authority: US
Inventors: Shunichiro Tsuchida; Tomiaki Miyata; Michihiko Takahashi
Original assignee: Fuji Photo Film Co Ltd
Current assignee: Fujifilm Holdings Corp
Priority date: 1965-02-24
Filing date: 1966-02-24
Publication date: 1971-01-26
Anticipated expiration: 1988-01-26
Also published as: GB1103806A; BE676853A; CH473404A; DE1547834A1

Abstract

AN IMPROVED PROCESS FOR STABILIZING A DEVELOPED SILVER HALIDE LIGHT-SENSITIVE MATERIAL UTILIZING A THIOCYANATE OR THIOUREA WHICH FURTHER COMPRISES SUBJECTING THE LIGHTSENSITIVE MATERIAL TO A WASHING BATH TREATMENT WHEREIN THE WASHING FLUID COMPRISES WATER AS THE SOLE COMPONENT WHICH IS UTILIZED TO REMOVE STABILIZING AGENTS, THE WASHING BATH BEING CONDUCTED FOR A PERIOD OF TIME SHORTER THAN SIXTY SECONDS AFTER EXPOSING, DEVELOPING AND STABILIZING SAID LIGHT-SENSITIVE MATERIAL.

Description

Jpn. 26,1971

PHOTOGRAPMC MNSITY SHUHNICHIRO TSUCHIDA ETAL 3,558,313

WATER WASH FOR STABILIZED SILVER HALIDE PHOTOGRAPHIC MATERIALS PHOTOGRAPMC DENSITY Filed Feb. 24, 1966 FIG] WASHING PERM!) III SECONDS HDTDGRIPHIC DENSITY SNUNICMRO TSUCIIM TOIMKI IIYITA IKZHMIKO TAKAMSII 37 J M, M,

-M) v A'I'IORNEY:

MING PERU) IN 8COIl0$ INVENTORS United States Patent Ofice 3,558,313 WATER WASH FOR STABILIZED SILVER HALIDE PHOTOGRAPHIC MATERIALS Shunichiro Tsuchida, Tomiaki Miyata, and Michihiko Takahashi, Kanagawa, Japan, assignors to Fuji Shashin Film Kabushiki Kaisha, Kanagawa, Japan Filed Feb. 24, 1966, Ser. No. 529,696 Claims priority, application Japan, Feb. 24, 1965, 40/ 10,328 Int. Cl. G03c 5/26, 5/38 US. CI. 96-50 3 Claims ABSTRACT OF THE DISCLOSURE An improved process for stabilizing a developed silver halide light-sensitive material utilizing a thiocyanate or thiourea which further comprises subjecting the lightsensitive material to a washing bath treatment wherein the washing fluid comprises water as the sole component which is utilized to remove stabilizing agents, the washing bath being conducted for a period of time shorter than sixty seconds after exposing, developing and stabilizing said light-sensitive material.

The present invention relates to a process for further increasing the stability of photographic images of silver halide photographic materials which have been developed and subjected to a so-called stabilizing treatment.

In order to make light-insensitive the unexposed silver halide of a silver halide photographic material, after light exposure and development, there have hitherto been adopted the following two methods. That is, the developed silver halide photographic material is fixed and the remaining silver halide is converted into a light-unstable silver complex salt, Which is then removed from the photographic material by water-washing. Or, the photographic material is subjected to a stabilizing treatment requiring no water-washing treatment to convert the unexposed silver halide into a light-stable silver complex salt, which is left in the thus stabilized silver halide photographic emulsion without being removed by water-washing. According to the latter stabilizing treatment, the treatment can be done quickly, but, in general, the qualities of the image are accompanied with many faults.

After exposure and development, there remains silver halide at the unexposed areas of the silver halide photographic material and metallic silver is formed at the exposed areas of the photographic material. In the subsequent stabilizing treatment, a silver complex salt-forming agent is supplied not only to the unexposed area, that is, the silver halide-remaining areas, but also to the exposed areas, that is, the metallic silver-formed areas. Hence the stabilized silver halide photographic material is dried and preserved in the state in which it contains the silver complex salt-forming agent together with the silver complex salt, since water-washing treatment is not applied. I

However, since the silver complex salt-forming agent is used in considerable excess of a theoretical amount to assure the stability of images to light, the hygroscopic property of the agent impedes the drying procedure and makes sticky the surface of the stabilized photographic material to be preserved. Further, there is a tendency in this case for the metallic silver composing the image to be gradually oxidized by the silver complex salt-forming agent into a silver complex salt, which reduces the photographic density of the image. That is, when the thus stabilized silver halide photographic material is preserved in the air, the color of the image of the photographic material is converted from black to brown or yellow owing to the reduction in photographic density and in an excessive case, the image tends to disappear. Such a phenom- 3,558,313 Patented Jan. 26, 1971 enon is liable to occur when the stabilized silver halide photographic material is preserved at high temperature and at high humidity.

For overcoming these difiiculties, the adoption of water-washing may be considered. But water-washing has been considered to be undesirable in the case of applying stabilizing treatment, because (1) the silver complex salt formed by the conventional stabilizing treatment is stable in the state that the silver complex salt-forming is present in an excessive amount, and (2) because, even though the silver complex salt and the silver complex salt-forming agent are washed out by water, a slight amount of silver complex salt remains in the photographic material, in the case of using as a stabilizing agent thiocyanates or thiourea, which is very unstable and reduces markedly the image.

However, the inventors have found that the application of washing to the thus stabilized silver halide photographic material for a limited period of time is desirable.

According to the process of this invention, a stabilized silver halide photographic material is subjected to washing with water or an aqueous solution for a period of time to secure the stability of the silver complex salt, that is, for a period shorter than 60 seconds, whereby the reduction of the photographic density of the image, the discoloration of the photographic, and the formation of sticky surface of the photographic material are prevented. Moreover, in the invention, the application of ferrotype drying to the stabilized silver halide photographic material is possible.

The washing bath in this invention may be used until the concentration of the silver complex salt-forming agent in the bath reaches 3%.

In the washing bath in this invention may be added effectively a fluorescent bleaching agent, such as Whitex BH (made by Sumitomo Kagaku K.K.) and Kayaphor S (Nihou Kayaku K.K.) to increase the whiteness.

Further, into the washing bath in this invention may be added an ultraviolet absorbing agent, such as, HPT (made by Dupont Company) and UV400 (made by Gen- 1eral Aniline & Film Corp.) to increase the stability of ight.

Furthermore, into the washing bath of this invention may be added a photo-wetting agent, such as, Dry Well (made by Fuji Photo-Film Co.), Konidux (made by Konishi Roku-Shashin Kogyo K.K.), and other surface active agents.

Still further, into the washing bath in this invention may be added a hardening agent to reduce the stickiness of the surface of the emulsion layer of the photographic material, such as, potassium alum, chromium alum, acetic acid, formaline, etc.

The following are the examples of this invention.

EXAMPLE 1 A silver halide photographic light-sensitive paper and a silver halide photographic light-sensitive film were exposed, developed treated in a stabilizing solution mainly comprising ammonium thiocyanate, and then subjected to water-washing. The results of the procedures are shown in FIG. 1 of the accompanying drawings, in which the graph shows the relation of the photographic density and the washing period. The solid line corresponds to the case of the silver halide photographic paper and the dotted line to the case of the silver halide photographic film. In the positive side (+AD) of the photographic density in the graph there is shown the increased photographic density of the unexposed areas of the photographic materials sub- {acted to a forced deterioration test of 15 hours by means of Shimazu Xenon Tester and in the negative side (AD) in the graph is shown the reduced photographic density of the areas of the photographic material having the photographic density of 1.8 (D) subjected to the forced deterioration test for days at the temperature of 50 C. and humidity of 90%.

The results show that the water-washing treatment for a period of shorter than 60 seconds is effective for the prevention of reduction of photographic density of the photographic image by heat and humidity while sufficiently securing the light-stability of the image.

EXAMPLE 2 Instead of water-bath washing in Example 1, waterspray washing was conducted and the results are shown in FIG. 2 of the accompanying drawing in which the testing procedures are the same as those in the case of FIG. 1 in Example 1, As shown in the graph of FIG. 2, waterspray washing of shorter than 5 seconds is effective for preventing the reduction of photographic density of the photographic images by heat and humidity while securing the stability of the photographic material to light.

EXAMPLE 3 A silver halide photographic light-sensitive paper and a silver halide photographic light-sensitive film were exposed, developed, treated in a stabilizing solution mainly comprising thiourea, and then subjected to water-washing. The results are shown in FIG. 3 of the accompanying drawing. The testing procedures are the same as in the case of Example 1.

It is clear from the results, that, when the water-washing period is shorter than 5 seconds, the application thereof is sufficiently effective for the prevention of the reduction of photographic density of images by moisture and heat while securing its stability to light as in Example 1.

EXAMPLE 4 Into 1 liter of water-washing bath was dissolved 5 g. of a fluorescent bleaching agent, Whitex BH. When a stabilized silver halide photographic light-sensitive paper was treated by the bath as in Example 1, the whiteness of the white ground of the photographic paper was increased and the reduction of photographic density of the image was sufficiently prevented. The results of testing preservability of the stabilized silver halide photographic paper subjected to the washing treatment for 2 seconds and a stabilized silver halide photographic paper subjected to no washing treatment (comparative sample) by the deterioration test, in the same manner as in Example 1, are as follows:

AD +AD Non-washed image 0. 60 0. 01 Washed image 0. 25 0. 01

EXAMPLE 5 -AD +AD Non-washed image 0. 60 0. 01 Washed image 0. 20 O. 01

EXAMPLE 6 A washing bath prepared by dissolving ml. of an ultraviolet absorber HPT in 1 liter of water-washing bath was used. Decoloring of the image was prevented and also the reduction of photographic density of the 4 image was sufficiently prevented. The results of the tests of the preservability of the stabilized silver halide photographic paper subjected to the washing treatment for 2 seconds and a stabilized comparative silver halide photographic paper subjected to no washing treatment are as follows:

AD +Al) Non-washed image 0. 58 0. 02 Washed image 0. 18 0.00

EXAMPLE 7 AD +AD Non-washed image 0. 0. 01 Washed image 0. 11 0. 00

EXAMPLE 8 A washing bath prepared by dissolving 15 g. of potassium alum and 10 ml. of acetic acid as a hardening agent in 1 liter of water-washing bath was used. By the treatment, the surface of the emulsion layer of a stabilized silver halide photographic material was hardened to reduce the stickiness of the surface and the reduction of the photographic density of the image was sutficiently prevented. The results of the tests of the preservability of the stabilized silver halide photographic paper and silver halide photographic film subjected to the washing treatment for 30 seconds and comparative samples subjected to no washing treatment are as follows:

AD +AD Paper Film Paper Film Non-washed image O. 57 1. 00 0. 01 0. 01 Washed image 0. 14 0. 18 O. 02 0. O1

EXAMPLE 9 A washing bath prepared by dissolving 15 ml. of Formalin (37%), 0.5 g. of boric acid, and 5.5 g. of sodium carbonate as a hardening agent into 1 liter of a waterwashing bath was used. By the treatment, the surface of the emulsion layer of a silver halide photographic material was hardened to reduce the stickiness and also the reduction of the photographic density of the image was sufficiently prevented. The results of the preservability tests are as follows:

AD +AD Paper Film Paper Film Non-washed image 0. 58 1. 00 0. 01 0. 01 Washed image O. 07 0. 05 0. 02 0. 00

EXAMPLE 10 together with the results from tests on comparative stabilized photographic materials subjected to no washing treatment by the deterioration test, as in Example 1:

-AD +AD Paper Film Paper Film Non-washed image 0.60 0.95 0.01 0.00 Washed image 0.22 0.14 03 0.00

EXAMPLE 11 -AD +AD Paper Film Paper Film Non-washed image 0. 60 0. 98 0.01 0. 00 Washed image 0. 25 0. 17 0. 03 0. 00

What we claim is:

1. In the process for stabilizing a developed silver halide light-sensitive material utilizing a member selected from the group consisting of thiocyanates and thiourea wherein the silver halide light-sensitive material is exposed, developed, stabilized, and dried, the improvement which comprises subjecting the light-sensitive material to a washing bath treatment for a period of time shorter than seconds, said washing bath consisting solely of water, said treatment being the only intervening step between said stabilizing and said drying step.

2. The process as claimed in claim 1 wherein said light-sensitive material is a silver halide light-sensitive film.

3. The process as claimed in claim 1 wherein said lightsensitive material is a silver halide light-sensitive paper.

References Cited UNITED STATES PATENTS 2,367,516 1/1945 Muehler et al 96-50 3,212,895 10/1965 Barber et al. 9661 3,250,617 5/1966 Sawdey 96-50 3,356,502 12/1967 Nasu et al. 96-50 FOREIGN PATENTS 1,233,010 4/ 1959 France 9661 39/25,774 Japan 96--61 OTHER REFERENCES Clafkides, P. Photographic Chemistry,, vol. I, 1958, pp. 158-60.

Focal Encyclopedia, vol. II, 1958, p. 1103.

NORMAN G. TORCHIN, Primary Examiner M. F. KELLEY, Assistant Examiner US. Cl. X.R. 96-61