Radiation imagery chemistry: process – composition – or product th – Radiation sensitive product – Silver compound sensitizer containing
Reexamination Certificate
2000-02-25
2001-11-27
Baxter, Janet (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Silver compound sensitizer containing
C430S569000, C430S599000, C430S604000, C430S605000
Reexamination Certificate
active
06322960
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to silver halide photographic emulsions and silver halide photographic light sensitive materials and in particular to silver halide photographic emulsions exhibiting stable performance independent of humidity at the time of exposure and having superiority in latent image stability, sensitivity and contrast and silver halide color photographic light sensitive materials by the use thereof.
BACKGROUND OF THE INVENTION
Along with recent popularization of compact labs, exposure of printing of silver halide photographic print paper is conducted at various kinds of places, and accordingly exposure is done under various conditions.
The use of exposure printers is accompanied by emission, which affects the temperature or humidity of ambient surroundings. Particularly, the use of color print paper, of which photographic performance is easily varied with temperature or humidity of the surroundings, causes unfavorable variation in color tone. Specifically at the time of starting of printing, print paper is easily affected under changes in temperature or humidity over time, producing problems such that in cases when a large number of prints of the same picture are made, a marked difference in tone between the start and the finish of printing occurs.
Iridium compounds are effective for improvement in reciprocity law failure, as disclosed in JP-B 43-4935 (hereinafter, the term, JP-B means a published Japanese Patent) and U.S. Pat. No. 4,997,751 and are also effective in increasing contrast. However, the use of the iridium compound results in deterioration in latent image stability at the initial stage after exposure, as described in Journal of Photographic Science vol. 33, page 201.
JP-A 10-307357 (hereinafter, the term, JP-A means an unexamined and published Japanese Patent Application) discloses a technique of introducing a deep and permanent electron trap into the interior of silver halide grains and satisfying a specified equation, thereby leading to enhanced high contrast of roomlight-handling photographic materials. JP-A 10-186558 discloses a technique of improving exposure dependence on humidity by the use of an emulsion evaluated on the basis of microwave photoconduction. However, sufficient photographic performance has not been obtained by these techniques.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a silver halide emulsion having high sensitivity and sufficient contrast suitable for silver halide color print paper and exhibiting latent image stability little affected by humidity at the time of exposure and a silver halide color photographic material.
The object of the present invention can be accomplished by the following constitution:
1. A silver halide emulsion containing silver halide grains having a chloride content of not less than 90 mol %, the silver halide grains each being internally doped with the following compound (A), compound (B) and compound (C): compound (A) meeting at least one of the following (a1) to (a6), except for compound (C);
(a1) a compound exhibiting an effect of enhancing an intensity of a microwave photoconduction signal,
(a2) a compound exhibiting an effect of increasing a decay time of a microwave photoconduction signal intensity,
(a3) a compound exhibiting an effect of enhancing a photographic sensitivity,
(a4) a compound forming a shallow electron trap capable of releasing a trapped electron in a time of less than 50 ns,
(a5) a compound forming an electron trap shallower than that of compound (C), or
(a6) a compound forming an electron trap of a depth of 0.03 to 0.3 eV;
compound (B) meeting at least one of the following (b1) to (b6), except for compound (C);
(b1) a compound exhibiting an effect of lowering an intensity of a microwave photoconduction signal,
(b2) a compound exhibiting an effect of decreasing a decay time of a microwave photoconduction signal intensity,
(b3) a compound exhibiting an effect of reducing a photographic sensitivity,
(b4) a compound forming a deep electron trap capable of holding a trapped electron in a time of not less than 5 sec.,
(b5) a compound forming an electron trap deeper than that of compound (C), or
(b6) a compound forming an electron trap of a depth of not less than 0.6 eV;
compound (C) of an iridium compound;
2. The silver halide emulsion described in 1., wherein the silver halide grains each are internally doped with compound (A) and exhibiting an intensity of a microwave photoconduction signal, a decay time of a microwave photoconduction signal intensity or a sensitivity of at least two times that of silver halide grains which are not doped with compound (A);
3. The silver halide emulsion described in 1., wherein the silver halide grains each are internally doped with compound (B) and exhibiting an intensity of a microwave photoconduction signal, a decay time of a microwave photoconduction signal intensity or a sensitivity of not more than ½ times that of silver halide grains which are not doped with compound (B);
4. The silver halide emulsion described in 1., wherein the silver halide grains each contain a region doped with compound (C) and a region doped with compound (B), the region doped with compound (C) and said region doped with compound (B) being adjacent or overlapping each other in the grain;
5. The silver halide emulsion described in 1., wherein the silver halide grains each contain a region doped with compound (C) and a region doped with compound (A), the region doped with compound (C) and the region doped with compound (A) being adjacent or overlapping each other in the grain;
6. The silver halide emulsion described in1., wherein the silver halide grains each contain a region doped with compound (A) and a region doped with compound (B), the region doped with compound (A) and the region doped with compound (B) being adjacent or crossed with each other in the grain;
7. The silver halide emulsion described in 1., wherein said silver halide grains each contain a region doped with compound (A) in the grain and the boundary of the region doped with compound (A) that is nearest to the surface of the grain is located at a depth of 0.01 to 0.035 &mgr;m from the grain surface;
8. The silver halide emulsion described in 1., wherein the silver halide grains each contain a region doped with compound (A) in the grain and the boundary of the region doped with compound (A) that is nearest to the surface of the grain is in the grain between 60 to 90% of the grain volume;
9. The silver halide emulsion described in 1., wherein the silver halide grains each contain a region doped with compound (C) in the grain and the boundary of the region doped with compound (C) that is nearest to the surface of the grain is located at a depth of 0.01 to 0.035 &mgr;m from the grain surface;
10. The silver halide emulsion described in 1., wherein the silver halide grains each contain a region doped with compound (C) in the grain and the boundary of the region doped with compound (C) that is nearest to the surface of the grain is in the grain between 60 to 90% of the grain volume;
11. The silver halide emulsion described in 1., wherein the silver halide grains each contain a region doped with compound (B) and a region doped with compound (C) in the grain, said region doped with compound (B) being internal to the region doped with compound (C);
12. The silver halide emulsion described in 11., wherein the silver halide grains further contain a region doped with compound (A) in the grain, said region doped with compound (A) being external to the region doped with compound (B);
13. The silver halide emulsion described in 12., wherein the region doped with compound (A), region doped with compound (B) and region doped with compound (C) each have a width of not more than 20 mol %, based on silver of the grain.
14. A high chloride silver halide emulsion containing silver halide grains having a chloride content of not less than 90 mol %, the silver halide grains each being doped in the grain with at least three metal complexes different in metal valenc
Ito Junji
Kuroda Koichiro
Murakami Shuji
Osawa Yumiko
Suzuki Shin'ichi
Baxter Janet
Bierman Jordan B.
Bierman, Muserlian and Lucas
Konica Corporation
Walke Amanda C
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