Radiation imagery chemistry: process – composition – or product th – Radiation sensitive product – Silver compound sensitizer containing
Reexamination Certificate
2001-02-02
2003-06-24
Letscher, Geraldine (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Silver compound sensitizer containing
C430S570000, C430S574000, C430S581000, C430S584000, C430S585000, C430S599000
Reexamination Certificate
active
06582895
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a novel methine compound, a silver halide photographic emulsion containing the same which is high sensitive and excellent in storage stability, and a silver halide photographic material comprising the same emulsion.
BACKGROUND OF THE INVENTION
Every endeavor has been done for higher sensitization and improvement of storage stability of a silver halide photographic material. It is known that the performances of a silver halide photographic material are greatly affected by sensitizing dyes which are used for spectral sensitization. Accordingly, many researchers have hitherto synthesized various kinds of sensitizing dyes and endeavored to investigate photographic performances. However, it is not possible to know the effects in advance.
Various trials of reduction sensitization for higher sensitization of a silver halide photographic material has been discussed for long. As useful compounds as the reduction sensitizers, e.g., tin compounds are disclosed in U.S. Pat. No. 2,487,850, polyamine compounds in U.S. Pat. No. 2,512,925, and thiourea dioxide series compounds in British Patent 789,823. Further, the characteristics of silver specks produced by various reduction sensitizing methods are compared in
Photographic Science and Engineering
, Vol. 23, p. 113 (1979), and dimethylamineborane, stannous chloride, hydrazine, and the methods of high pH ripening and low pAg ripening have been adopted. Reduction sensitizing methods are further disclosed in U.S. Pat. Nos. 2,518,698, 3,201,254, 3,411,917, 3,779,777 and 3,930,867. Not only the selection of reduction sensitizers but the contrivances of reduction sensitizing methods are disclosed in JP-B-57-33572 and JP-B-58-1410 (the term “JP-B” as used herein means an “examined Japanese patent publication”).
However, according to the studies by the present inventors, it has been confirmed that when spectral sensitization is performed by adsorbing sensitizing dyes onto reduction sensitized silver halide grains, it is extremely difficult to obtain sufficient spectral sensitization without causing undesired effects on photographic performance (e.g., the increase of fog during storage).
For that reason, a technique of spectrally sensitizing reduction-sensitized silver halide grains in high sensitivity without causing adverse effects such as fog during storage has been required.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a silver halide photographic emulsion which is high speed and excellent in storage stability, and a silver halide photographic material containing the same.
The above object of the present invention has been attained by the following means.
(1) A silver halide photographic emulsion which comprises at least one methine compound represented by the following formula (I):
wherein X
1
and X
2
each represents an oxygen atom, a sulfur atom, a selenium atom, or N—R
3
, wherein R
3
represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a heterocyclic group; V
1
and V
2
each represents a monovalent substituent; n
1
and n
2
each represents 0, 1, 2, 3 or 4; L
1
, L
2
and L
3
each represents a methine group; l represents an integer of 0 to 3; M represents a counter ion for balancing electric charge; m represents a number necessary for balancing electric charge; and R
1
and R
2
each represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group, but at least either R
1
or R
2
represents the alkyl group represented by any of the following formulae:
R
a
=(Q
a
)
r
CO{overscore (N)}SO
2
R
aa
R
b
=(Q
b
)
s
SO
2
{overscore (N)}COR
bb
R
c
=(Q
c
)
t
CO{overscore (N)}COR
cc
R
d
=(Q
d
)
u
SO
2
{overscore (N)}SO
2
R
dd
R
e
=(Q
e
)
v
X
wherein Raa, Rbb, Rcc and Rdd each represents an alkyl group, an aryl group, a heterocyclic group, an alkoxyl group, an aryloxy group, a heterocyclyloxy group, or an amino group; Qa, Qb, Qc, Qd and Qe each represents a divalent linking group; X represents SO
3
−
, CO
2
−
, or PO
3
2−
; and r, s, t, u and v each represents an integer of 1 or more, but when X represents SO
3
−
, V represents 1 or 2.
(2) The silver halide photographic emulsion comprising a methine compound as described in the above item (1), wherein 1 in formula (I) represents 0.
(3) The silver halide photographic emulsion comprising a methine compound as described in the above item (1) or (2), wherein either X
1
or X
2
represents an oxygen atom and the other represents a sulfur atom.
(4) The silver halide photographic emulsion comprising a methine compound as described in the above item (1), (2) or (3), wherein at least either R
1
or R
2
represents a sulfoethyl group and the other represents a group having a dissociable group.
(7) The silver halide photographic emulsion comprising a methine compound as described in the above item (1), (2), (3), (4), (5) or (6), wherein either V
1
or V
2
represents an aromatic group and the other represents a chlorine atom, and each is substituted on the 5-position.
(8) The silver halide photographic emulsion comprising a methine compound as described in the above item (1), wherein the methine compound is represented by the following formula:
wherein when V
1
is Cl, V
2
is a phenyl group, or when V, is a phenyl group, V
2
is Cl; when R
1
is (CH
2
)
2
SO
3
—, R
2
is (CH
2
)
3
SO
3
—, or when R
1
is (CH
2
)3SO
3
—, R
2
is (CH
2
)
2
SO
3
—; M represents a counter ion for balancing electric charge; and m represents a number necessary for balancing electric charge.
(9) The silver halide photographic emulsion comprising a methine compound as described in the above item (1), (2), (3), (4), (5), (6) or (7), wherein the silver halide photographic emulsion comprises at least one sensitizing dye having different structure from the methine compound represented by formula (I) and having spectral absorption maximum wavelength of from 400 nm to 500 nm.
(10) The silver halide photographic emulsion comprising a methine compound as described in the above item (1), (2), (3), (4), (5), (6), (7) or (8), wherein the silver halide grains of the silver halide photographic emulsion have been reduction-sensitized.
(11) A silver halide photographic material which comprises the silver halide photographic emulsion as described in the above item (1), (2), (3), (4), (5), (6), (7), (8) or (9).
DETAILED DESCRIPTION OF THE INVENTION
Formula (I) is described in further detail below.
X
1
and X
2
each represents an oxygen atom, a sulfur atom, a selenium atom, or N—R
3
, wherein R
3
represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a heterocyclic group, preferably represents an oxygen atom or a sulfur atom, and particularly preferably either X
1
or X
2
represents an oxygen atom and the other represents a sulfur atom, and most preferably X
1
represents a sulfur atom and X
2
represents an oxygen atom.
V
1
and V
2
each represents a monovalent substituent. The monovalent substituents are not particularly restricted (the substituents of V
1
and V
2
are hereinafter called V collectively). Examples of V include, e.g., a halogen atom (e.g., chlorine, bromine, iodine, fluorine), a mercapto group, a cyano group, a carboxyl group, a phosphoric acid group, a sulfo group, a hydroxyl group, a carbamoyl group having from 1 to 10, preferably from 2 to 8, and more preferably from 2 to 5, carbon atoms (e.g., methylcarbamoyl, ethylcarbamoyl, morpholino), a sulfamoyl group having from 0 to 10, preferably from 2 to 8, and more preferably from 2 to 5, carbon atoms (e.g., methylsulfamoyl, ethylsulfamoyl, piperidinosulfonyl), a nitro group, an alkoxyl group having from 1 to 20, preferably from 1 to 10, and more preferably from 1 to 8, carbon atoms (e.g., methoxy, ethoxy, 2-methoxyethoxy, 2-phenylethoxy), an aryloxy group having from 6 to 20, preferably from 6 to 12, and more preferably fr
Hanaki Naoyuki
Hioki Takanori
Morimoto Kiyoshi
Fuji Photo Film Co. , Ltd.
Letscher Geraldine
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