Claims
- 1. A method of preparing a silver halide emulsion containing core/shell silver halide grains comprising two or more phases having different silver halide compositions, a core portion containing silver iodide in an amount of 15 to 40 mol %, said method comprising;
- preparing seed grains,
- introducing a water-soluble halide and a water-soluble silver salt to initiate grain growth to form silver halide on said seed grains, said growth being conducted in the presence of fine grains of silver iodide having an average grain size of 0.01 to 0.1 .mu.m, and
- introducing a water-soluble iridium salt after at least 70% of the ultimate grain size of said silver halide grains is reached.
- 2. The method of claim 1, wherein said core/shell grains are subjected to a chemical ripening treatment.
- 3. The method of claim 2, wherein said iridium ions are added at a time prior to a chemical ripening treatment.
- 4. The method of claim 1, wherein said iridium ions are added in an amount of not more than 1.times.10.sup.-5 mols per mol of silver halide.
- 5. The method of claim 4, wherein said iridium ions are added in an amount of not more than 1.times.10.sup.-7 mols per mol of silver halide.
- 6. A silver halide photographic light-sensitive material comprising a silver halide emulsion layer containing core/shell silver halide grains comprising two or more phases having different silver halide compositions, a core portion containing silver iodide in an amount of 15 to 40 mol %, said silver halide grains being grown by:
- preparing seed grains,
- introducing a water-soluble halide and a water-soluble silver salt to initiate grain growth to form silver halide on said seed grains, said grain growth being carried out in the presence of fine grains of silver iodide having an average grain size of 0.01 to 0.1 .mu.m, and
- introducing a water-soluble iridium salt after at least 70% of the ultimate grain size of said silver halide grains is reached.
- 7. The material of claim 6 wherein said core/shell grains are subjected to a chemical ripening treatment.
- 8. The material of claim 7 wherein said iridium ions are added prior to said chemical ripening treatment.
- 9. The material of claim 6 wherein said iridium ions are added in an amount of not more than 1.times.10.sup.-5 mols per mol of silver halide.
- 10. The material of claim 9 wherein said iridium ions are added in an amount of not more than 1.times.10.sup.-7 mols per mol of silver halide.
Priority Claims (1)
Number |
Date |
Country |
Kind |
1-165080 |
Jun 1989 |
JPX |
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Parent Case Info
This application is a continuation of application Ser. No. 08/048,072, filed Apr. 15, 1993, now abandoned, which is a continuation of application Ser. No. 07/815,899, filed Dec. 31, 1991, now abandoned, which is a continuation of application Ser. No. 07/542,729, filed Jun. 22, 1990, now abandoned.
US Referenced Citations (11)
Foreign Referenced Citations (1)
Number |
Date |
Country |
312999 |
Apr 1989 |
EPX |
Continuations (3)
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Number |
Date |
Country |
Parent |
48072 |
Apr 1993 |
|
Parent |
815899 |
Dec 1991 |
|
Parent |
542729 |
Jun 1990 |
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