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Description  |
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FIELD OF THE INVENTION
This invention relates to silver halide photographic emulsions and,
particularly, to silver halide photographic emulsions spectrally
sensitized with at least two sensitizing dyes mutually exhibiting
supersensitizing activities. More particularly, this invention relates to
silver halide photographic emulsions having spectral sensitivity enhanced
particularly in the green wavelength region.
BACKGROUND OF THE INVENTION
It is known that addition of certain kinds of cyanine dyes is highly
effective in enhancing the sensitivity of silver halide photographic
emulsions. In such a case, the cyanine dye added to the silver halide
photographic emulsion is adsorbed by the silver particles in the emulsion
to add an absorption band of greater wavelength to the absorption band
which is inherent in the silver halide. This phenomenon is called
"spectral sensitization". It is also known that the efficiency of color
sensitization by this dye may be notably enhanced when the dye is used in
the presence of a second, certain kind of specifically selected dye or
other organic substance and that a selective combination of certain types
of dyes provides superadditively high sensitivity. This effect is called
"supersensitization". Generally, combined use of two or more dyes more
often than not fails to improve sensitivity or even results in loss of
sensitivity. Therefore, supersensitization is a specific phenomenon
depending on very specific combinations of compounds.
The maximum luminosity (maximum visibility) of man is about 545 nm. From
the fact that the human eyes are acutely sensitive to light in the green
wavelength region, it is inferred that the technique for sensitizing the
green wavelength region is particularly significant in the whole technique
for spectral sensitization. The term "luminosity" in a certain wavelength
means a reciprocal of quantity of radiation having the wavelength required
for providing a certain lightness.
Addition of a certain type of benzimidazolocarbocyanine dye is an unusually
effective means of enhancing the sensitivity of silver halide to green
light. This fact is described, e.g., in U.S. Pat. Nos. 2,739,149 and
2,912,329 and in British Pat. Nos. 654,690 and 815,172. The conventional
benzimidazolocarbocyanine dye often fails to provide sufficient
sensitization when it is used by itself. Several techniques involving
combined use of the benzimidazolocarbocyanine dye with certain other dye
with a view to the effect of supersensitization have been reported to the
art. Descriptions dealing with such techniques are found, for example, in
U.S. Pat. No. 3,506,443, Japanese Patent Publication No. 4936/68 and
Japanese Patent Application (OPI) No. 82416/77 (the term "OPI" as used
herein refers to a "published unexamined Japanese patent application").
Supersensitized emulsions using the conventionally known
benzimidazolocarbocyanine dye, however, have suffered aggravated fog of
the applied emulsion upon exposure to high temperature or to the
combination of high temperature and high humidity or degraded stability of
the applied emulsion to withstand effects of aging, with resultant
extensive loss of sensitivity of the emulsion.
Improvements directed to overcoming the drawbacks suffered by
supersensitized emulsions using the benzimidazolocarbocianine dye, namely,
the aggravated fog of the applied emulsion under the influence of high
temperature or the combination of high temperature and high humidity and
the gradual degradation of sensitivity of the emulsion under the influence
of aging, therefore, have constituted one of the important problems to be
solved in techniques for the production of lightsensitive materials.
SUMMARY OF THE INVENTION
An object of this invention is to provide silver halide photographic
emulsions which prevent the aggravated fog of the emulsion under the
influence of high temperature or the combination of high temperature and
high humidity, minimize the degradation of sensitivity of the emulsion
upon aging, and enjoy high stability to withstand the adverse effects of
aging.
It has now been found that the aforementioned object and other various
objects of the present invention are accomplished by the preparation of a
silver halide photographic emulsion, characterized by containing therein
at least one benzimidazolocarbocyanine dye having a fluorine-substituted
alkyl group of the formula --CH.sub.2 (CF.sub.2).sub.m.sbsb.1 H (wherein
m.sub.1 is an integer having a value of 1 to 8), bound to at least one of
the nitrogen atoms of an imidazole ring as shown by the following formula
(I) and the benzimidazolocarbocyanine dyes having a fluorine-substituted
alkyl group of the formula --(CH.sub.2).sub.l.sbsb.2
(CF.sub.2).sub.m.sbsb.2 F (wherein l.sub.2 and m.sub.2 each is 0 or an
integer having a value of 1 to 8, providing that the total value of
l.sub.2 and m.sub.2 is an integer greater than 0), bound to at least one
of the nitrogen atoms of an imidazole ring as shown by the following
formula (II), in combination with at least one dye represented by the
following formulae (III) and (IV).
The compounds of formula (I) are represented by:
##STR1##
wherein m.sub.1 is an integer having a value of 1 to 8, R.sub.1, R.sub.2
and R.sub.3, which may be identical with or different from one another,
independently represent a --CH.sub.2 (CF.sub.2).sub.l.sbsb.1 H group or a
substituted or unsubstituted alkyl group, providing that at least one of
R.sub.1, R.sub.2 and R.sub.3 possesses an acid substituent (such as, for
example, a sulfonic acid group or carboxylic acid group), l.sub.1, which
may be equal to or not equal to m.sub.1, is an integer having a value of 1
to 8, V.sub.1, V.sub.2, V.sub.3 and V.sub.4, which may be identical with
or different from one another, independently represent a hydrogen atom, a
halogen atom, a substituted alkyl group, an unsubstituted alkyl group, an
alkoxy group, an acyl group, an acyloxy group, an alkoxycarbonyl group, a
carbamoyl group, a sulfamoyl group, a cyano group, or a trifluoromethyl
group, X.sub.1 represents an anion, and n.sub.1 is 1 or 2, providing that
n.sub.1 is 1 where the dye forms an intramolecular salt.
The compounds of formula (II) are represented by:
##STR2##
wherein l.sub.2 is 0 or an integer having a value of 1 to 8, m.sub.2 is 0
or an integer having a value of 1 to 8, providing that the total value of
l.sub.2 and m.sub.2 is an integer greater than 0, R.sub.4, R.sub.5 and
R.sub.6, which may be identical with or different from one another,
independently represent a --(CH.sub.2).sub.j (CF.sub.2).sub.k F group or a
substituted or unsubstituted alkyl group, providing that at least one of
R.sub.4, R.sub.5 and R.sub.6 represents an alkyl group containing an acid
substituent (such as, for example, a sulfonic acid group or carboxylic
acid group), j is 0 or an integer having a value of 1 to 8, k is 0 or an
integer having a value of 1 to 8, providing that the total value of j and
k is an integer greater than 0, V.sub.5 , V.sub.6, V.sub.7 and V.sub.8,
which may be identical with or different from one another, independently
represent a hydrogen atom, a halogen atom, a substituted alkyl group, an
unsubstituted alkyl group, an alkoxy group, an acyl group, an acyloxy
group, an alkoxycarbonyl group, a carbamoyl group, a sulfamoyl group, a
cyano group, or a trifluoromethyl group, X.sub.2 represents an anion, and
n.sub.2 is 1 or 2, providing that n.sub.2 is 1 where the dye forms an
intramolecular salt.
The compounds of formula (III) are represented by:
##STR3##
wherein Y.sub.1 represents an oxygen atom, a sulfur atom, a selenium atom,
or N--R.sub.10, Z.sub.1 and Z.sub.2, which may be identical with or
different from each other, independently represent an atomic group
necessary for the formation of an unsubstituted or substituted benzene
ring or naphthalene ring, R.sub.7, R.sub.8 and R.sub.10 independently
represent an unsubstituted or substituted alkyl group, providing that at
least one of R.sub.7, R.sub.8 and R.sub.10 possesses an acid substituent,
R.sub.9 represents a hydrogen atom, an alkyl group, or an aralkyl group,
X.sub.3 represents an anion, and n.sub.3 is 1 or 2, providing that n.sub.3
is 1 where the dye forms an intramolecular salt.
The compounds of formula (IV) are represented by:
##STR4##
wherein Y.sub.2 represents a sulfur atom, a selenium atom, or N--R.sub.14,
Z.sub.3 and Z.sub.4, which may be identical with or different from each
other, independently represent an atomic group necessary for the formation
of an unsubstituted or substituted benzene ring or naphthalene ring,
R.sub.11, R.sub.12, R.sub.13 and R.sub.14 independently represent an
unsubstituted or substituted alkyl group, providing that at least one of
R.sub.11, R.sub.12, R.sub.13 and R.sub.14 possesses an acid substituent,
X.sub.4 represents an anion, and n.sub.4 is 1 or 2, providing that n.sub.4
is 1 where the dye forms an intramolecular salt.
In the sensitizing dyes of formula (I), the substituents indicated
hereinbelow are preferred among the possible substituents. Specifically,
in the case of R.sub.1, R.sub.2 and R.sub.3, which may be identical with
or different from one another, preferred substituents include --CH.sub.2
(CF.sub.2).sub.l.sbsb.1 H groups (wherein l.sub.1, which may be equal or
not equal to m.sub.1, is an integer having a value of 1 to 8), unsaturated
alkyl groups having not more than 6 carbon atoms (such as, for example, a
methyl group, an ethyl group, a propyl group, a butyl group, a pentyl
group, a vinylmethyl group, and a cyclohexyl group), and substituted alkyl
groups [such as, for example, alkyl groups of not more than 6 carbon atoms
which have, as substituents therefor, a carboxy group, a sulfo group, a
cyano group, halogen atoms (such as, for example, a fluorine atom, a
chlorine atom, and a bromine atom, providing that when the substitution
involves a fluorine atom, those groups embraced in --CH.sub.2
(CF.sub.2).sub.m.sbsb.1 H and --CH.sub.2 (CF.sub. 2).sub.l.sbsb.1 H are
not included), a hydroxy group, alkoxycarbonyl groups having not more than
8 carbon atoms (such as, for example, a methoxycarbonyl group, an
ethoxycarbonyl group, a phenoxycarbonyl group and a benzyloxycarbonyl
group), alkoxy groups of not more than 8 carbon atoms (such as, for
example, a methoxy group, an ethoxy group, a benzyloxy group and a
phenethyloxy group), monocyclic aryloxy groups of not more than 10 carbon
atoms (such as, for example, a phenoxy group and a p-tolyloxy group),
acyloxy groups of not more than 3 carbon atoms (such as, for example, an
acetyloxy group and a propionyloxy group), acyl groups of not more than 8
carbon atoms (such as, for example, an acetyl group, a propionyl group, a
benzoyl group and a mesyl group), carbamoyl groups (such as, for example,
a carbamoyl group, an N,N-dimethylcarbamoyl group, a morpholinocarbonyl
group and a piperidinocarbonyl group), sulfamoyl groups (such as, for
example, a sulfamoyl group, an N,N-dimethylsulfamoyl group, a
morpholinosulfonyl group and a piperidinosulfonyl group), and aryl groups
of not more than 10 carbon atoms (such as, for example, a phenyl group, a
p-hydroxyphenyl group, a p-carboxyphenyl group, a p-sulfophenyl group and
an .alpha.-naphthyl group)].
In the case of V.sub.1, V.sub.2, V.sub.3 and V.sub.4, which may be
identical with or different from one another, preferred substituents
include a hydrogen atom, halogen atoms (such as, for example, a fluorine
atom, a chlorine atom and a bromine atom), alkyl groups of not more than 6
carbon atoms (such as, for example, a methyl group, an ethyl group, a
vinylmethyl group and a cyclohexyl group), acyl groups of not more than 8
carbon atoms (such as, for example, an acetyl group, a propionyl group, a
benzoyl group and a mesyl group), acyloxy groups of not more than 3 carbon
atoms (such as, for example, an acetoxy group), alkoxycarbonyl groups of
not more than 8 carbon atoms (such as, for example, a methoxycarbonyl
group, an ethoxycarbonyl group and a benzyloxycarbonyl group), carbamoyl
groups of not more than 8 carbon atoms (such as, for example, a carbamoyl
group, an N,N-dimethylcarbamoyl group, a morpholinocarbonyl group and a
piperidinocarbonyl group), sulfamoyl groups of not more than 8 carbon
atoms (such as, for example, a sulfamoyl group, an N,N-dimethylsulfamoyl
group, a morpholinosulfonyl group and a piperidinosulfonyl group), a cyano
group, a trifluoromethyl group and a hydroxy group.
In the sensitizing dyes of the formula (I) usable for the present
invention, the substituents indicated hereinbelow are particularly
preferred among the possible substituents. Specifically, in the case of
R.sub.1, R.sub.2 and R.sub.3, which may be identical with or different
from one another, particularly preferred substituents include --CH.sub.2
(CF.sub.2).sub.l.sbsb.1 H groups (wherein l.sub.1, which may be equal or
not equal to m.sub.1, is an integer having a value of 1 to 8), unsaturated
alkyl groups of not more than 6 carbon atoms (such as, for example, a
methyl group, an ethyl group, a propyl group, a butyl group, a pentyl
group, a vinylmethyl group and a cyclohexyl group), and substituted alkyl
groups of not more than 12 carbon atoms [such as, for example, alkyl
groups of not more than 6 carbon atoms which have, as substituents
therefor, a carboxy group, a sulfo group, a cyano group, halogen atoms
(providing that when the substitution involves a fluorine atom, those
groups embraced in --CH.sub.2 (CF.sub.2).sub.m.sbsb.1 H and --CH.sub.2
(CF.sub.2).sub.l.sbsb.1 H are not included), a hydroxy group,
alkoxycarbonyl groups of not more than 6 carbon atoms, alkoxy groups of
not more than 6 carbon atoms, monocyclic aryloxy groups of not more than
10 carbon atoms, acyloxy groups of not more than 3 carbon atoms, acyl
groups of not more than 8 carbon atoms, sulfamoyl groups, and aryl groups
of not more than 10 carbon atoms] . In the case of V.sub.1, V.sub.2,
V.sub.3 and V.sub.4, which may be identical with or different from one
another, particularly preferred substituents include a hydrogen atom,
halogen atoms (such as, for example, a chlorine atom), alkyl groups of not
more than 4 carbon atoms (such as, for example, a methyl group, an ethyl
group and a vinylmethyl group), acyl groups of not more than 7 carbon
atoms (such as, for example, an acetyl group, a propionyl group and a
benzoyl group), alkoxycarbonyl groups of not more than 8 carbon atoms,
carbamoyl groups of not more than 6 carbon atoms (such as, for example, a
carbamoyl group, an N,N-dimethylcarbamoyl group and a morpholinocarbamoyl
group), sulfamoyl groups (such as, for example, a sulfamoyl group, an
N,N-dimethylsulfamoyl group, a morphonylsulfonyl group and a
piperidinosulfonyl group), a cyano group, a trifluoromethyl group and a
hydroxy group. The combination in which V.sub.1 and V.sub.2 are each a
chlorine atom and either or both of V.sub.3 and V.sub.4 are each a
trifluoromethyl group, a chlorine atom, or a cyano group is especially
preferred.
In the sensitizing dyes of formula (II), the substituents indicated
hereinbelow are preferred among the possible substituents. Specifically,
in the case of R.sub.4, R.sub.5 and R.sub.6, which may be identical with
or different from one another, preferred substituents include
--(CH.sub.2).sub.j (CF.sub.2).sub.k F groups (wherein j, which may be
equal or not equal to k, is 0 or an integer having a value of 1 to 8,
providing that the total value of j and k is greater than 0), unsaturated
alkyl groups having not more than 6 carbon atoms (such as, for example, a
methyl group, an ethyl group, a propyl group, a butyl group, a pentyl
group, a vinylmethyl group and a cyclohexyl group), and substituted alkyl
groups [such as, for example, alkyl groups of not more than 6 carbon atoms
which have, as substituents therefor, a carboxy group, a sulfo group, a
cyano group, halogen atoms (such as, for example, a fluorine atom, a
chlorine atom and a bromine atom), a hydroxy group, alkoxycarbonyl groups
having not more than 8 carbon atoms (such as, for example, a
methoxycarbonyl group, an ethoxycarbonyl group, a phenoxycarbonyl group
and a benzyloxycarbonyl group), alkoxy groups of not more than 8 carbon
atoms (such as, for example, a methoxy group, an ethoxy group, a benzyloxy
group and a phenethyloxy group), monocyclic aryloxy groups of not more
than 10 carbon atoms (such as, for example, a phenoxy group and a
p-tolyloxy group), acyloxy groups of not more than 3 carbon atoms (such
as, for example, an acetyloxy group and a propionyloxy group), acyl groups
of not more than 8 carbon atoms (such as, for example, an acetyl group, a
propionyl group, a benzoyl group and a mesyl group), carbamoyl groups
(such as, for example, a carbamoyl group, an N,N-dimethylcarbamoyl group,
a morpholinocarbonyl group and a piperidinocarbonyl group), sulfamoyl
groups (such as, for example, a sulfamoyl group, an N,N-dimethylsulfamoyl
group, a morpholinosulfonyl group and a piperidinosulfonyl group), and
aryl groups of not more than 10 carbon atoms (such as, for example, a
phenyl group, a 4-chlorophenyl group, a 4-methylphenyl group and an
.alpha.-naphthyl group)], providing that at least one of R.sub.4, R.sub.5
and R.sub.6 represents an alkyl group of not more than 6 carbon atoms
substituted with a sulfo group or a carboxy group.
In the case of V.sub.5, V.sub.6, V.sub.7 and V.sub.8, which may be
identical with or different from one another, preferred substituents
include a hydrogen atom, halogen atoms (such as, for example, a fluorine
atom, a chlorine atom and a bromine atom), alkyl groups of not more than 6
carbon atoms (such as, for example, a methyl group, an ethyl group, a
vinylmethyl group and a cyclohexyl group), acyl groups of not more than 8
carbon atoms (such as, for example, an acetyl group, a propionyl group, a
benzoyl group and a mesyl group), acyloxy groups of not more than 3 carbon
atoms (such as, for example, an acetoxy group), alkoxycarbonyl groups of
not more than 8 carbon atoms (such as, for example, a methoxycarbonyl
group, an ethoxycarbonyl group and a benzyloxycarbonyl group), carbamoyl
groups of not more than 8 carbon atoms (such as, for example, a carbamoyl
group, an N,N-dimethylcarbamoyl group, a morpholinocarbonyl group and a
piperidinocarbonyl group), sulfamoyl groups of not more than 8 carbon
atoms (such as, for example, a sulfamoyl group, an N,N-dimethylsulfamoyl
group, a morpholinosulfonyl group and a piperidinosulfonyl group), a cyano
group, a trifluoromethyl group and a hydroxy group.
In the sensitizing dyes of formula (II), l.sub.2 and m.sub.2 are
particularly preferable, in the case that the total value of l.sub.2 and
m.sub.2 is not greater than 8 and greater than 0, the substituents
indicated hereinbelow are particularly preferred among the possible
substituents. Specifically, in the case of R.sub.4, R.sub.5 and R.sub.6,
which may be identical with or different from one another, particularly
preferred substituents include --(CH.sub.2).sub.j (CF.sub.2).sub.k F
groups (wherein j, which may be equal or not equal to k, represents 0 or
an integer of the value of 1 to 8, providing that the total value of j and
k is an integer greater than 0 and preferably the total value of j and k
is not greater than 8 and greater than 0), unsaturated alkyl groups of not
more than 6 carbon atoms (such as, for example, a methyl group, an ethyl
group, a propyl group, a butyl group, a pentyl group, a vinylmethyl group
and a cyclohexyl group), and substituted alkyl groups of not more than 12
carbon atoms [such as, for example, alkyl groups of not more than 6 carbon
atoms which have, as substituents therefor, a carboxy group, a sulfo
group, a cyano group, halogen atoms, a hydroxy group, alkoxycarbonyl
groups of not more than 6 carbon atoms, alkoxy groups of not more than 6
carbon atoms, monocyclic aryloxy groups of not more than 10 carbon atoms,
acyloxy groups of not more than 3 carbon atoms, acyl groups of not more
than 8 carbon atoms, sulfamoyl groups, and aryl groups of not more than 10
carbon atoms], providing that at least one of R.sub.4, R.sub.5 and R.sub.6
represents an alkyl group of not more than 6 carbon atoms containing a
sulfo group or a carboxy group. In the case of V.sub.5, V.sub.6, V.sub.7
and V.sub.8, which may be identical with or different from one another,
particularly preferred substituents include a hydrogen atom, halogen atoms
(such as, for example, a chlorine atom), alkyl groups of not more than 4
carbon atoms (such as, for example, a methyl group, an ethyl group and a
vinyl methyl group), acyl groups of not more than 7 carbon atoms (such as,
for example, an acetyl group, a propionyl group and a benzoyl group),
alkoxycarbonyl groups of not more than 8 carbon atoms, carbamoyl groups of
not more than 6 carbon atoms (such as, for example, a carbamoyl group, an
N,N-dimethylcarbamoyl group and a morpholinocarbamoyl group), sulfamoyl
groups of not more than 6 carbon atoms (such as, for example, a sulfamoyl
group, an N,N-dimethylsulfamoyl group, a morphonylsulfonyl group and a
piperidinosulfonyl group), a cyano group, a trifluoromethyl group and a
hydroxy group. The combination in which V.sub.5 and V.sub.7 are each a
chlorine atom and either or both of V.sub.6 and V.sub.8 are each a
trifluoromethyl group, a chlorine atom, or a cyano group is especially
preferred.
In the sensitizing dyes of formula (III), those substituents of Y.sub.1,
Z.sub.1, Z.sub.2 and R.sub.7 through R.sub.10 indicated hereinbelow are
preferred among the possible substituents.
In the case of Y.sub.1, preferred substituents include an oxygen atom, a
sulfur atom, a selenium atom, and N--R.sub.10. Here, an oxygen atom is
preferred to the other substituents.
In the case of Z.sub.1 and Z.sub.2, which may be identical with or
different from each other, preferred substituents include atomic groups
necessary for the formation of an unsubstituted or substituted benzene
ring or naphthalene ring.
Desirable substituents for the benzene ring or naphthalene ring include
halogen atoms (such as, for example, a fluorine atom, a chlorine atom and
a bromine atom), alkyl groups of not more than 6 carbon atoms (such as,
for example, a methyl group, an ethyl group, a propyl group, a vinylmethyl
group, a 2-methylpropyl group, a butyl group and a hexyl group), alkoxy
groups of not more than 8 carbon atoms (such as, for example, a methoxy
group, an ethoxy group, a butyloxy group, a benzyloxy group and a
phenethyloxy group), aryl groups of not more than 8 carbon atoms (such as,
for example, a phenyl group, a 4-methylphenyl group and a 4-chlorophenyl
group), aryloxy groups of not more than 8 carbon atoms (such as, for
example, a phenoxy group, a 4-methylphenoxy group and a 4-chlorophenoxy
group), acyl groups of not more than 8 carbon atoms (such as, for example,
an acetyl group, a propionyl group, a benzoyl group and a mesyl group),
alkoxycarbonyl groups of not more than 8 carbon atoms (such as, for
example, a methoxycarbonyl group, an ethoxycarbonyl group, a
butyloxycarbonyl group and a benzyloxycarbonyl group), acyloxy groups of
not more than 3 carbon atoms (such as, for example, an acetyloxy group and
a propionyloxy group), a cyano group, a trifluoromethyl group, a carboxyl
group and a hydroxy group. In the case of Z.sub.1 and Z.sub.2,
particularly desirable substituents are benzene derivatives having a
phenyl group, a chlorine atom, and a methoxy group as substituents bound
to the 5-position of the benzene ring.
In the case of R.sub.7, R.sub.8 and R.sub.10, desirable substituents
include alkyl groups of not more than 8 carbon atoms (such as, for
example, a methyl group, an ethyl group, a propyl group, a vinylmethyl
group, a butyl group, a pentyl group, a hexyl group, a heptyl group and an
octyl group) and alkyl groups of not more than 6 carbon atoms which have,
as substituents therefor, a hydroxy group, a carboxy group, a sulfo group,
a cyano group, halogen atoms (such as, for example, a fluorine atom, a
chlorine atom and a bromine atom), alkoxycarbonyl groups of not more than
8 carbon atoms (such as, for example, a methoxycarbonyl group, an
ethoxycarbonyl group and a benzyloxycarbonyl group), alkoxy groups of not
more than 8 carbon atoms (such as, for example, a methoxy group, an ethoxy
group, a butyloxy group, a benzyloxy group and a phenethyloxy group),
aryloxy groups of not more than 8 carbon atoms (such as, for example, a
phenoxy group and a p-tolyloxy group), acyloxy groups of not more than 3
carbon atoms (such as, for example, an acetyloxy group and a propionyloxy
group), acyl groups of not more than 8 carbon atoms (such as, for example,
an acetyl group, a propionyl group, a benzoyl group and a 4-fluorobenzoyl
group), carbamoyl groups of not more than 6 carbon atoms (such as, for
example, a carbamoyl group, an N,N-dimethylcarbamoyl group, a
morpholinocarbonyl group and a piperidinocarbonyl group), sulfamoyl groups
of not more than 6 carbon atoms (such as, for example, a sulfamoyl group,
an N,N-dimethylsulfamoyl group, a morpholinosulfonyl group and a
piperidinosulfonyl group), and aryl groups of not more than 10 carbon
atoms (such as, for example, a phenyl group, a p-fluorophenyl group, a
p-hydroxyphenyl group, a p-carboxyphenyl group and a p-sulfophenyl group).
It is imperative here that at least one of R.sub.7, R.sub.8 and R.sub.10
should possess an acid substituent.
In the case of R.sub.9, preferred substituents include a hydrogen atom,
alkyl groups of not more than 4 carbon atoms (such as, for example, a
methyl group, an ethyl group, a propyl group and a butyl group) and
aralkyl groups of not more than 10 carbon atoms (such as, for example, a
benzyl group, a phenethyl group and a 3-phenylpropyl group).
In the sentitizing dyes of the general formula (IV) usable for the present
invention, those substituents of Y.sub.2, Z.sub.3, Z.sub.4 and R.sub.11
through R.sub.14 indicated hereinbelow are preferred among the possible
substituents. In the case of Y.sub.2, preferred substituents include a
sulfur atom, a selenium atom and N--R.sub.14. In the case of Z.sub.3 and
Z.sub.4, which may be identical with or different from each other,
preferred substituents include atomic groups necessary for the formation
of an unsubstituted or substituted benzene ring or naphthalene ring.
Preferred substituents for the benzene ring or naphthalene ring include
halogen atoms (such as, for example, a fluorine atom, a chlorine atom and
a bromine atom), alkyl groups of not more than 6 carbon atoms (such as,
for example, a methyl group, an ethyl group, a propyl group, a vinylmethyl
group, a 2-methylpropyl group, a butyl group and a hexyl group), alkoxy
groups of not more than 8 carbon atoms (such as, for example, a methoxy
group, an ethoxy group, a butyloxy group, a benzyloxy group and a
phenethyloxy group), aryl groups of not more than 8 carbon atoms (such as,
for example, a phenyl group, a 4-methylphenyl group and a 4-chlorophenyl
group), aryloxy groups of not more than 8 carbon atoms (such as, for
example, a phenoxy group, a 4-methylphenoxy group and a 4-chlorophenoxy
group), acyl groups of not more than 8 carbon atoms (such as, for example,
an acetyl group, a propionyl group, a benzoyl group and a mesyl group),
alkoxycarbonyl groups of not more than 8 carbon atoms (such as, for
example, a methoxycarbonyl group, an ethoxycarbonyl group, a
butyloxycarbonyl group and a benzyloxycarbonyl group), acyloxy groups of
not more than 3 carbon atoms (such as, for example, an acetyloxy group and
a propionyloxy group), a cyano group, a trifluoromethyl group, a carboxyl
group and a hydroxy group.
In the case of R.sub.11, R.sub.12, R.sub.13 and R.sub.14, preferred
substituents include alkyl groups of not more than 8 carbon atoms (such
as, for example, a methyl group, an ethyl group, a propyl group, a
vinylmethyl group, a butyl group, a pentyl group, a hexyl group, a heptyl
group and an octyl group) and substituted alkyl groups of not more than 6
carbon atoms which have, as substituents therefor, a hydroxy group, a
carboxyl group, a sulfo group, a cyano group, halogen atoms (such as, for
example, a fluorine atom, a chlorine atom and a bromine atom),
alkoxycarbonyl groups of not more than 8 carbon atoms (such as, for
example, a methoxycarbonyl group, an ethoxycarbonyl group and a
benzyloxycarbonyl group), alkoxy groups of not more than 8 carbon atoms
(such as, for example, a methoxy group, an ethoxy group, a butyloxy group,
a benzyloxy group and a phenethyloxy group), aryloxy groups of not more
than 8 carbon atoms (such as, for example, a phenoxy group, a
4-methylphenoxy group and a 4-chlorophenoxy group), acyloxy groups of not
more than 3 carbon atoms (such as, for example, an acetyloxy group and a
propionyloxy group), acyl groups of not more than 8 carbon atoms (such as,
for example, an acetyl group, a propionyl group, a benzoyl group and a
4-fluorobenzoyl group), carbamoyl groups of not more than 6 carbon atoms
(such as, for example, a carbamoyl group, an N,N-dimethylcarbamoyl group,
a morpholinocarbonyl group and a piperidinocarbonyl group), sulfamoyl
groups of not more than 6 carbon atoms (such as, for example, a sulfamoyl
group, an N,N-dimethylsulfamoyl group, a morpholinosulfonyl group and a
piperidinosulfonyl group), and aryl groups of not more than 10 carbon
atoms (such as, for example, a phenyl group, a p-fluorophenyl group, a
p-hydroxyphenyl group, a p-carboxyphenyl group and a p-sulfophenyl group).
It is essential here that at least one of R.sub.11, R.sub.12, R.sub.13 and
R.sub.14 should possess an acid substituent.
Specific examples of the dyes represented by formula (I), formula (II),
formula (III) and formula (IV) of this invention will be cited
hereinbelow. It should be noted that the dyes usable for the present
invention are not limited to these specific examples.
##STR5##
The compounds of formulae (I) and (II) of the present invention can be
easily produced by synthesizing fluorinated alkyl esters, fluorinated
alkylamines, and fluorinated alkyl iodides of sulfonic acids according to
the manner as described in J. Org. Chem., 26, 4021 (1961), J. Amer. Chem.
Soc., 77, 3149 (1955), J. Amer. Chem. Soc., 78, 4999 (1956), etc., and
then treating these synthesis products in accordance with the methods
disclosed in U.S. Pat. Nos. 2,739,149 and 2,912,329 and British Pat. Nos.
654,690 and 815,172.
At least one of the compounds of formulae (I) and (II) and at least one of
the compounds of formulae (III) and (IV) are contained in the silver
halide photographic emulsion in a combined amount of from
1.times.10.sup.-6 mol to 5.times.10.sup.-3 mol, preferably from
1.times.10.sup.-5 mol to 3.times.10.sup.-3 mol, and particularly
preferably from 5.times.10.sup.-5 mol to 2.times.10.sup.-3 mol, per mol of
silver halide. The molar ratio of dye of formulae (III) and (IV) to dye of
formulae (I) and (II) as used in the emulsion is generally in the range of
from 1:20 to 10:1, and preferably in the range of from 1:10 to 5:1.
The dyes which are used in the present invention can be directly dispersed
in the emulsion. Optionally, these dyes may be dissolved in a suitable
solvent such as, for example, methyl alcohol, ethyl alcohol, ethyl
alcohol, propyl alcohol, methyl cellosolve, any of the halogenated
alcohols disclosed in Japanese Patent Application (OPI) No. 9715/73 and
U.S. Pat. No. 3,756,830, acetone, water, or pyridine, or a suitable
mixture thereof, and added in the form of solutions to the emulsion.
The aforementioned sensitizing dyes may be uniformly dispersed in the
silver halide emulsion before the emulsion is applied to a suitable
support. Of course, this dispersion may be effected at any step in the
whole course of the preparation of the silver halide emulsion.
The silver halide to be used in the photographic emulsion of the present
invention may be any member selected from the group consisting of silver
bromide, silver iodobromide, silver iodochlorobromide, silver
chlorobromide and silver chloride. Preferred silver halides are silver
bromide, silver chlorobromide, silver iodobromide and silver
iodochlorobromide. Particularly preferred silver halides are silver
iodobromide and silver bromide.
The silver halide particles in the photographic emulsion may be in the
shape of such regular crystals as cubes and octahedrons or such irregular
crystals as spheres and tablets or in the combination shape of varying
crystals. Otherwise, the photographic emulsion may comprise the silver
halide particles having various shapes of crystals.
The individual silver halide particles may possess different phases in the
internal core and in the surface layer or they may be formed of one
uniform phase throughout the volume. They may be of a type such that they
form a latent image chiefly in the surface portion (such as those in
negative emulsion) or a type such that they form a latent image chiefly in
the inner portion (such as those of inner latent image type emulsion or
preliminary fogged direct reversal type emulsion). Preferably, they may be
of a type containing a fogging agent and used for inner latent image type
direct reversal emulsion.
The silver halide particles may be produced by a method which effects
formation of the particles in the presence of excess silver ions
(popularly called "reversal mixing method"). As one form of the double jet
mixing method, the so-called controlled double jet method which maintains
the pAg of the liquid phase for the formation of the silver halide, at a
fixed level, may be adopted.
By this method, there is obtained a silver halide emulsion in which the
particles are regular crystals of a substantially uniform particle size.
Two or more separately formed dissimilar types of silver halide emulsions
may be mixed and used.
During the formation of silver halide particles, a silver halide solvent
such as, for example, ammonia, potassium rhodanite, ammonium rhodanite, or
thioether compound may be used for controlling the growth of silver halide
particles.
The formation or physical aging of silver halide particles may be allowed
to proceed in the presence of a cadmium salt, zinc salt, thallium salt,
iridium salt or complex salt thereof, rhodium salt or complex salt
thereof, or iron salt or complex salt thereof.
Examples of the inner latent image type emulsion usable for the present
invention include conversion type emulsions, core/shell type emulsions,
and emulsions incorporating dissimilar metals, such as are disclosed in
U.S. Pat. Nos. 2,592,250, 3,206,313, 3,447,927, 3,761,276 and 3,935,014.
Silver halide emulsions are generally subjected to chemical sensitization.
More specifically, the sulfur sensitizing method, which uses an activated
gelatin or a sulfur-containing compound capable of reacting with silver
(such as, for example, thiosulfates, thioureas, mercapto compounds, and
rhodanines), the reduction sensitizing method which uses a reducing
substance (such as, for example, stannous salts, amines, hydrazines,
formamidine sulfonic acids, and silane compounds), and the noble metal
sensitizing method which uses a noble metal compound (such as, for
example, complex salts of gold and complex salts of metals of Group VIII
of the Periodic Table of Elements such as Pt, Ir and Pd) may be used
either independently or in suitable combination.
Concrete examples of the chemical sensitizer usable herein include sulfur
sensitizers such as allylthiocarbamide, thiourea, sodium thiosulfate, and
cystine, noble metal sensitizers such as potassium chloroaurate, aurous
thiosulfate, and potassium chloropalladate, and reducing sensitizers such
as tin chloride, phenyl hydrazine, and reductones. Other sensitizers such
as polyoxyethylene compounds, polyoxypropylene compounds, and compounds
having a quaternary ammonium group may be also included.
The photographic em | | |
