Radiation imagery chemistry: process – composition – or product th – Radiation sensitive product – Silver compound sensitizer containing
Reexamination Certificate
2000-02-15
2002-03-05
Baxter, Janet (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Silver compound sensitizer containing
C430S567000, C430S569000, C430S600000
Reexamination Certificate
active
06352823
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a silver halide photographic material. More particularly, the present invention relates to a high speed silver halide photographic material utilizing the technique of dopants.
BACKGROUND OF THE INVENTION
As one of the techniques of modifying silver halide grains to bring about as much improvement as is expected in the properties of a silver halide photographic material as a whole, there is known a technique of incorporating a substance (dopant) other than silver and halide ions into silver halide grains. This technique is referred to as “a doping technique”. In particular, many researches on the technique of doping transition metal ions have been made. As a result, it is generally recognized that the transition metal ions incorporated as a dopant into silver halide grains can effectively modify photographic properties even when the amount thereof is minute.
Besides the technique of doping transition metal ions, there is known the technique of doping silver halide grains with transition metal complexes having cyanide ions as ligands to heighten the sensitivity of silver halide emulsions. In particular, many disclosures have been made about the emulsions having sensitivities increased by doping with the hexacyano complexes containing the group VIII metals. As the dopants containing cyanide ions, for instance, a hexacyanoferrate (II) complex and a hexacyanoferrate (III) complex are disclosed in JP-B-48-35373 (The term “JP-B” as used herein means an “examined Japanese patent publication”). However, the invention cited above regards the sensitivity increasing effect as being limited to the cases of complexes containing iron ion and having no relation to the species of ligands. Many other cases are known where high sensitivity can be conferred on emulsions by doping them with hexacyanoferrate (II) complexes. Such cases are disclosed, e.g., in JP-A-5-66511 (The term “JP-A” as used herein means an “unexamined published Japanese patent application”) and U.S. Pat. No. 5,132,203. There are also known the emulsions which are doped with cyano-complexes of metals other than iron to obtain high sensitivity. For instance, JP-A-2-20853 discloses that silver halide emulsions can acquire high sensitivity by comprising silver iodochloride doped with a rhenium, ruthenium, osmium or iridium complex. Many of other metal complexes are also used as dopant, and can produce not only the sensitivity increasing effect but also various effects, such as an improvement in reciprocity failure and an increase in contrast. For instance, U.S. Pat. No. 2,448,060 discloses the emulsions sensitized by doping them with a platinum (II) or palladium (IV) complex having halogen ions as ligands. And U.S. Pat. No. 3,790,390 discloses the emulsions doped with cyano-cobalt (III) complexes in addition to the emulsions doped with cyano-iron (II) or cyano-iron (III) complexes, wherein spectral sensitizing dyes are also contained. Further, the silver halide grains formed in the presence of a rhodium (III) complex containing 3, 4, 5 or 6 cyanide ions as ligands are disclosed in U.S. Pat. No. 4,847,191. Those patent prove that the high intensity failure can be diminished by dopants. In European Patents 0335425 and 0336426 and JP-A-2-20854 are disclosed the silver halide emulsions doped with rhenium, ruthenium, osmium or iridium complexes having at least 4 cyano-ligands. Therein, it is described that the doped emulsions are improved in storage stabilities of sensitivity and gradation and reduced in low intensity failure. European Patent 0336427 and JP-A-2-20852 disclose the silver halide emulsions respectively using vanadium, chromium, manganese, iron, ruthenium, osmium, rhenium and iridium complexes having the octahedrasl structure with nitrosyl or thionitrosyl ligands, wherein the low intensity reciprocity failure is improved without attended by lowering of medium illumination sensitivity. As the dopants other than transition metal ions, the emulsions doped with bismuth or lead ions are disclosed in U.S. Pat. No. 3,690,888, and the emulsions containing the group XIII or XIV metal ions are disclosed in JP-A-7-128778.
With respect to the ligands of complexes used as dopant, the cyanide ions are regarded as most popular, but halide ions are also used frequently. As examples of a dopant having the structure of [MCl
6
]
n−
wherein M is a metal, mention may be made of the hexachlororuthenium, hexachloroiridium and hexachlororhenium complexes disclosed, e.g., in JP-A-63-184740, JP-A-1-285941, JP-A-2-20852 and JP-A-2-20855. Further the octahedral rhenium complexes having halogeno, nitrosyl, thionitrosyl, cyano, aquo or/and thiocyano ligands are disclosed as dopants in European Patent 0336689 and JP-A-2-20855. In addition, the emulsion containing a octahedral transition metal complex having one carbonyl ligand and the emulsion containing a octahedral transition metal complex having two oxo ligands are disclosed as those having useful photographic properties in JP-A-3-118535 and JP-A-3-118536, respectively.
In recent years, techniques involving the doping of silver halide grains with complexes having an organic compound as a ligand for the purpose of modifying the properties of emulsion have been studied. U.S. Pat. Nos. 5,360,712, 5,457,021 and 5,462,849, European Patent (EP) 0709724, JP-A-7-72569 and JP-A-8-179452 disclose examples of the use of many complexes comprising organic compounds as ligands. It is described that emulsions comprising silver halide grains doped with [(NC)
5
Fe(&mgr;-4,4′-bipyridine) Fe(CN)
5
]
6−
in particular have a remarkably raised sensitivity. JP-A-11-24194 discloses that emulsions having a high sensitivity and improved reciprocity failure is obtained by doping with [Fe(CO)
4
(P(Ph)
3
)]
0
or [Fe(CO)
3
(P(Ph)
2
)]
0
. Further, JP-A-11-102042 discloses that [M(CN)
5
L]
'−
(wherein M represents Fe
2+
, Ru
2+
or Ir
'+
), [Fe(CO)
4
L]
0
, [M′(CN)
3
L]− (wherein M′ represents PD
2+
or Pt
2+
) and [IrCl
5
L]
2−
type complexes wherein L is 2-mercapto-benzimidazole, 5, methyl-s-triazolo(1.5-A)pyrimidine-7-ol or 2-mercapto-1,3,4-oxadiazole can provide high speed emulsions. Moreover, JP-A-10-293377 discloses that emulsions doped with [RuCl
5
L′]
2−
(wherein L′ represents imidazole, benzimidazole or derivative thereof) provide an extremely increased contrast at which the resulting sensitivity is far higher than that of emulsions doped with the conventional desensitized high contrast dopants.
When the octahedral complexes coordinated with six ligands are incorporated as dopants into silver halide grains, as described in references, including J. Phys.:
Condens. Matter
, 9 (1997) 3227-3240, literatures and patents, the [AgX
6
]
5−
unit (X=halogen ion) in silver halide grains is replaced by the complex molecules so that the central metal (ion) occupies the lattice position of Ag
+
ion and the ligands occupy the lattice position of halide ions. Accordingly, U.S. Pat. No. 5,360,712 discloses that the complex to be used as a dopant must be occupied in the coordination site of central metal (ion) by halogen or pseudo-halogen ions in a proportion of half or more and the organic compound which can be used as a ligand must have a proper molecular size with respect to the size of the space in the crystal lattice as a host.
On the other hand, U.S. Pat. No. 3,672,901, JP-A-2-259749 and JP-A-336537 disclose examples of the use of, as a dopant, a complex comprising no halogen or pseudo-halogen ions bonded thereto at the coordination sites of metal ion such as [Fe(ETDA)]
2−
(wherein EDTA represents ethylenediamine tetraacetic acid) and [Ir(C
2
O
4
)
3
]
3−
. The above described U.S. Pat. No. 5,360,712 discloses that these dopants have no large effect. According to this patent, these complexes have all coordination sites o
Baxter Janet
Fuji Photo Film Co. , Ltd.
Walke Amanda
LandOfFree
Silver halide photographic material does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Silver halide photographic material, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Silver halide photographic material will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2868639