Radiation imagery chemistry: process – composition – or product th – Radiation sensitive product – Silver compound sensitizer containing
Reexamination Certificate
2001-08-08
2003-04-08
Letscher, Geraldine (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Silver compound sensitizer containing
C430S607000, C430S608000, C430S613000, C430S598000, C430S264000, C430S267000, C430S570000
Reexamination Certificate
active
06544725
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority from the prior Japanese Patent Applications No. 2000-239940, filed Aug. 8, 2000; and No. 2001-205040, filed Jul. 5, 2001, the entire contents of both of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a lightsensitive silver halide photographic emulsion, a silver halide photographic lightsensitive material containing the same, and a method of enhancing the sensitivity of a lightsensitive silver halide photographic emulsion.
2. Description of the Related Art
With respect to silver bromide or silver iodobromide tabular grains whose main planes are (111) faces, processes for producing the same and technologies for utilizing the same are disclosed in, for example, U.S. Pat. Nos. 4,434,226, 4,439,520, 4,414,310, 4,433,048, 4,414,306 and 4,459,353. Thus, the advantages such as an improvement of sensitivity/graininess relationship and an enhancement of sensitivity, including an enhancement of color sensitizing effect, attained by sensitizing dyes are known. Further, reference can be made to, for example, Jpn. Pat. Appln. KOKAI Publication No. (hereinafter referred to as JP-A-) 58-113926, JP-A's-58-113927, 58-113928, 2-838, 2-28638 and 2-298935. Attempts to improve various photographic properties by intentionally introducing dislocations therein under control are known. JP-A-63-220238 discloses a method of introducing dislocation lines in the periphery of tabular grains. JP-A-1-102547 discloses a method of introducing dislocation lines in the main planes of tabular grains. JP-A-3-237450 discloses tabular grains of 3 or more aspect ratio having dislocation lines, chemically sensitized with the use of, for example, a selenium sensitizer, a gold sensitizer or a sulfur sensitizer. JP-A-6-27564 discloses tabular grains having dislocation lines localized in fringe portions thereof only.
With respect to silver bromide or silver iodobromide tabular grains whose main planes are (100) faces, there are the following various processes.
For example, there can be mentioned the process of JP-A-51-88017 (monodispersed seed grains are ripened in the presence of ammonia, thereby forming silver bromide (100) tabular grains), the process of JP-A-58-95337 (wherein seed grains are ripened in the absence of silver ion complexing agents other than halides, thereby forming silver bromide (100) tabular grains), the process of JP-A-6-308648, EP No. 670515A2, JP-A's-7-234470 and 8-122950 (wherein one or more halide composition gap faces are formed in seed grains or at the time of seed grain formation so as to introduce crystal defects for accelerating anisotropic growth, thereby forming (100) tabular grains), the process of EP No. 0534395A1 (wherein nuclei of high AgCl content are formed in a dispersion medium solution containing I
−
ions so as to generate crystal defects, thereby forming (100) tabular grains) and the process of JP-A-8-339044 (wherein grains are formed in the presence of a compound selected from among specific adsorbents capable of accelerating the formation of (100) faces, thereby forming (100) tabular grains).
Grains of high silver chloride content tend to become grains having (100) faces as external surfaces under customary production conditions, and grains having served practical use have been cubic. Examples of hitherto developed tabular (100) grains can be found in, for example, U.S. Pat. Nos. 5,320,938, 5,264,337 and 5,292,632.
Grains of high silver chloride content having (111) faces as external surfaces (hereinafter referred to as (111) grains) have been utilized. Examples thereof are disclosed in JP-A-6-138619.
Special measures are required for producing (111) grains of high silver chloride content. Wey in U.S. Pat. No. 4,399,215 discloses a process for producing tabular grains of high silver chloride content with the use of ammonia. Because of the use of ammonia in the production of grains according to this process, silver chloride grains of high solubility are produced at higher solubility, with the result that it has been difficult to produce practically useful small-size grains. Further, because the pH value at the time of production is as high as 8 to 10, the process has had such a disadvantage that fogging is likely to occur. Maskasky in U.S. Pat. No. 5,061,617 discloses (111) grains of high silver chloride content produced with the use of thiocyanates.
Methods of incorporating additives (crystal habit-controlling agents) at the time of grain formation in order to produce grains of high silver chloride content having (111) faces as external surfaces without causing any solubility increase are known. The methods are described in, for example, U.S. Pat. No. 4,400,463 (azaindenes+thioether peptizers), U.S. Pat. No. 4,783,398 (2-4 -dithiazolidinone), U.S. Pat. No. 4,713,323 (aminopyrazolopyrimidine), U.S. Pat. No. 4,983,508 (bispyridinium salts), U.S. Pat. No. 5,185,239 (triaminopyrimidine), U.S. Pat. No. 5,178,997 (7-azaindole compound), U.S. Pat. No. 5,178,998 (xanthine), JP-A-64-70741 (dyes), JP-A-3-212639 (aminothioethers), JP-A-4-283742 (thiourea derivatives, by Ishiguro), JP-A-4-335632 (triazolium salts), JP-A-2-32 (bispyridinium salts) and JP-A-8-227117 (monopyridinium salts).
Methods of sensitizing tabular grains with the use of epitaxial junction are disclosed in JP-A's-58-108526 and 59-133540. Applications thereof to tabular grains of smaller thickness or larger equivalent circle diameter are disclosed in JP-A's-8-69069, 8-101472, 8-101474, 8-101475, 8-171162, 8-171163, 8-101473, 8-101476, 9-211762 and 9-211763 and U.S. Pat. Nos. 5,612,176, 5,614,359, 5,629,144, 5,631,126, 5,691,127 and 5,726,007.
With respect to the above various emulsions, there is a strong demand for the development of an emulsion of low fogging and high sensitivity.
How to use sensitizing dyes are well known. In particular, combinations of sensitizing dyes are often employed for the purpose of supersensitization. Representative examples thereof are described in U.S. Pat. Nos. 2,688,545, 2,977,229, 3,397,060, 3,522,052, 3,527,641, 3,617,293, 3,628,964, 3,666,480, 3,672,898, 3,679,428, 3,703,377, 3,769,301, 3,814,609, 3,837,862 and 4,026,7007, GB Nos. 1,344,281 and 1,507,803, Jpn. Pat. Appln. KOKOKU Publication No. (hereinafter referred to as JP-B-) 43-4936 and JP-B-53-12375, and JP-A's-52-110618, 52-109925 and 52-110618.
On the other hand, an emulsion having undergone a spectral sensitization realizing high red sensitivity effected by a combination of an onium salt and a cyanine dye is known as described in JP-A-61-43740. An advantageous addition amount of this onium salt is described as being in the range of 0.25 to 100 times the weight of cyanine dye. Actually, the onium salt is added in an equimolar or more amount relative to the mole of cyanine dye. When a large amount of sensitizing dye can be effectively functioned, the color sensitization effect by sensitizing dye is enhanced. However, as a result of investigations made in the present invention, it has become apparent that, in a system loaded with a large amount of sensitizing dye, the sensitivity increase effect is slight even if an equimolar or more amount of adsorptive onium salt is used in combination with a cyanine dye in emulsions. Thus, there is a demand for the development of a technology for exerting a high sensitivity increase effect despite small addition amounts.
Although the joint use of onium salts with photographic emulsions is known as apparent from the above, the effect of the combined use with (111) face silver bromide/silver iodobromide tabular grains, (100) face silver bromide/silver iodobromide tabular grains, (100) face grains of high silver chloride content, (111) face grains of high silver chloride content and epitaxial grains is still unknown.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to provide a high-speed silver halide photographic emulsion for photographing which is
Fuji Photo Film Co. , Ltd.
Letscher Geraldine
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