Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
FP-1631
- ~ 31 7502
Internal latent imaqe type light-sensitive silver halide
photographic material
BACKGROUND OF THE INVENTION
This invention relates to an internal latent image type
light-sensitive silver halide photographic material, and,
particularly, to an internal latent image type light-sen-
sitive silver halide photographic material that can
afford a color positive image stable to the fogging
treatment at the time of the color developing treatment
or the like.
In these years, it has become possible to take a photo-
graph Erom an original such as a manuscript or typescript
for printiny or a reversal film on an internal latent
image type light-sensitive silver halide photographic
material by utilizing a copying apparatus, followed by
fogging in a color developing solution and thereafter
developing, to obtain a positive image directly on a
sheet of color photographic paper or on a color film.
For this reason, there has become available such a
copying apparatus installed in photograph shops, copy
shops and so forth.
However, in order to obtain a stable image with good
quality by the developing in the above photographic
- 131750~
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system, it is required for the processing performances of
processing solutions to be always kept in a constant
state. Accordingly, since the respective processing
solutions are consumed and deteriorated when a large
quantity of light-sensitive materials are processed for
color development and so forth, it is necessary to make
ready for replenishing solutions for appropriately
replenishing the respective processing solutions to cover
a shortage, or recover the deteriorated activity of
processing solutions by use of replenishing solutions to
maintain the initial activity, thus carrying out stable
processing. Particularly when the deteriorated process-
ing solutions are replenished, it follows as a matter of
course that the processing solutions are overflowed and
collected as waste liquor. The waste liquor thus
collected may sometimes contain harmful components or
components undesirable for preventing environmental
pollution, and therefore it is necessary to beforehand
make them harmless before the waste liquor is thrown
away. Thus, it requires much cost and labor to make
harmless the harmful components in the processing solu-
tions. In particular, an organic solvent having a log P
of 0.4 or more, such as benzyl alcohol acting as a color
development accelerator has so high values for BOD and
COD that such a solvent is desired to be used in an
amount as small as possible or not to be used at all.
However, if the color developing is carried out by using
the organic solvent such as benzyl alcohol in an amount
as small as possible or without using it, there can be a
problem that the oxidized product of a color developing
agent produced by the color development reaction may
preferentially react with sulfite ions used as an anti-
oxidant of the color developing agent in the developing
solution, rather than undergo the coupling reaction to
react with a coupler in a light-sensitive material,
thereby causing a lowering of the image density.
_ 3 _ 1317502
As a means for solving this problem, it is effective to
lower the concentration of the sulfite ions to enhance
the above coupling reaction. If, however, the processing
is carried out with use of a color developing solution
having a lowered sulfite ion concentration, there can be
a problem that the image may suffer great variation
depending on the variation of processing conditions. For
example, in the light-sensitive material containing an
internal latent image type silver halide grains compris-
ing a silver bromide shell as described in U.S. PatentNo. 3,206,313, there can be a problem that a positive
image may readily vary depending on the variation factors
at the time of fogging.
Namely, this variation, when fogged by light, may occur
because the illuminance of light may be decreased owing
to the deterioration of a light source, or the exposure
amount at a light-sensitive face may be decreased owing
to the Eilter action caused by coloring due to oxidation
of the color developing solution. When fogged by a fog-
ging agent, there may occur a lowering of the concentra-
tion of the fogging agent because of the air oxidation or
the like. In particular, it may sometimes occur that the
maximum density of the image to be obtained is extremely
lowered because of the above variation, to raise another
problem.
Now, as a techni~ue for restraining the lowering of the
image density, reported is to apply chemical ripening to
a certain degree on the surface of a silver halide grain
(see U.S. Patent No . 3,761,276)~ This, however, can not
necessarily be satisfactory.
SUMMARY OF THE INVENTION
An object of this invention is provide an internal latent
image type light-sensitive silver halide photographic
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material that can afford a positive image in a stable
state, and a second object thereof is to provide a inter-
nal latent image type light-sensitive silver halide
photographic material that can be processed by a process-
ing solution having less environmental load of wasteliquor.
In this invention, the above objects can be achieved by
an internal latent image type light-sensitive silver
halide photographic material capable of forming a color
positive image by effecting surface development process-
ing after fogging was carried out, and/or while fogging
is carried out, with use of a color developing solution
containing 1 g/lit or less of a solvent having a log P of
0.4 or more, and having a low sulfite ion concentration,
wherein a silver halide grain contained in at least one
layer of photographic constituent layers of said light-
sensitive material comprises a core and at least one
layer of a shell covering said core, and said shell con-
tains at least silver chloride as its surface composi-
tion.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
_ _ _ . _
In the light-sensitive material of this invention, the
silver halide grain contained in at least one photogra-
phic constituent layer thereof comprises a core and at
least one layer of a shell covering said core, and said
shell contains at least silver chloride as its surface
composition. Accordingly, there can be used silver
halides having any halogen composition as the surface
compostion so long as the silver chloride is substantial-
ly contained as the surface composition of the shell.
For example, they may include silver chloride, silver
chlorobromide, silver chloroiodobromide and silver
chloroiodide.
_ 5 _ 1 3 1 7502
The shell layer of the above silver halide grain in this
invention may entirely cover the surface of the silver
halide grain, or may selectively cover part of the
surface. In this invention, the shell surface layer
containing silver chloride may preferably occupies 10 %
or more of the grain surface.
The shell in the above silver halide grain may comprise a
single layer having a compositionally single silver
halide, or may be a composite shell comprising two or
more layers. In the preferred embodiment, an amount of
the silver chloride in the silver halide grain is 50 mole
% or more.
In the case the composite layer shell is used, this com-
prises at least an outermost layer and a layer contiguous
thereto, but may have the structure such that layers
having different silver halide composition from each
other are laminated.
The shell layer of said composite layer may also have the
structure such that the silver halide composition conti-
nuously changes in the diametrical direction of the
silver halide grain.
In the case the above composite layer shell is used, the
whole of the grain or the inside thereof may have any
silver halide composition so long as the silver chloride
is contained in the outermost layer, or at least the
surface thereof, of the composite layer shell, or the
surface portion of the shell corresponding to the layer
contiguous to the outermost layer. There may be includ-
ed, for example, silver iodobromide, silver bromide,
silver chlorobromide, silver chloroiodide, silver chloro-
iodobromide, etc. It is preferred that an amount of thesilver chloride in the surface composition of the shell
layer is 50 mole ~ or more.
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The shell may preferably cover 50 % or more of the sur-
face area of the core, and may particularly preferably
cover the core entirely.
The core may preferably chiefly comprise silver bromide,
or may further contain silver chloride and/or silver
iodobromide. The shape of the silver halide grain which
forms the core may be of any shape, for example, a cube,
a regular octahedron, a dodecahedron, a tetradecahedron,
or a mixed form of these; or a sphere, a flat plate, a
free-shaped grain, or an appropriately mixed form of
these. In practicing this invention, the average grain
size and grain size distribution of the silver halide
grain constituting the core can be varied in a wide range
depending on the photographic performances desired, but
the grain size distribution of a narrower width is more
preferred. In other words, the silver halide grain
constituting the core may preferably be substantially
monodisperse.
Here, the "core is comprised of a monodisperse silver
halide grain" means that in the silver halide grain
constituting the core, the weight of silver halide grains
included in a grain size range of ~ 20 % with an average
grain size r as the central value comprises 60 % or more,
preferably 70 % or more, particularly preferably 80 % or
more, of the total silver halide weight.
Here, the average grain size r refers to the grain size
ri at which the product of the frequency ni of the grain
having the grain size ri, and ri3, i.e., ni x ri3, makes
a maximum (effective numeral: three figures; smallest
figure number is rounded).
The grain size herein mentioned refers to the diameter in
the case of a spherical silver halide grain, and, in the
case of the grains other than the spherical grain, it
1317502
refers to the diameter assumed by calculating its pro-
jected image into a round image having the same area.
The grain size can be determined, for example, by pro-
jecting the grain with enlargement to 10,000 to 50,000
magnification with use of an electron microscope, and
actually measure on a print obtained the grain diameter
or area at the time of projection (assuming that the
number of grains to be measured is 1,000 or more indis-
criminately).
As methods for producing the above monodisperse core
emulsion, there can be used, for example, the double jet
method as disclosed in Japanese Patent Publication No.
15 36890/1973, Japanese Unexamined Patent Publications No.
48520/1979 and No. 65521/1979, etc. In addition, there
can be also used the pre-mixing method as disclosed in
Japanese ~nexamined Patent Publication No. 158220/1979.
In the working of this invention, the core of the silver
halide grain may be subjected to chemical sensitization
or doped with a metallic ion, or both of these may be
applied or none of both oE these may be applied at all.
As the chemical sensitiæation, there can be employed any
of sensitizing methods according to sulfur sensitization,
gold sensitization, reduction sensitization, noble metal
sensitization and a combination of any of these sensitiz-
ing methods. Thiosulfate, thioureas, thiazoles, rhoda-
nines and other compounds can be used as a sulfur sensi-
tizer. Such methods are described, for example, in U.S.
Patents No. 1,574,944, No. 1,623,499, No. 2,410,689, No.
3,656,955, etc.
The core of the silver halide grain used in the working
of this invention can be also sensitized by a water
soluble gold compound as described, for example, in U.S.
- 8 _ 1 3 1 7~ 02
Patent No. 2,399,083, No. 2,597,856, No. 2,642,361, etc.,
or can be also sensitized with use of a reduction sensi-
tizer. Reference to such methods can be made in the
disclosures, for example, in U.S. Patents No. 2,487,850,
5 No. 2,518,698, No. 2,983,610, etc.
Still also, noble metal sensitization can be carried out
with use of noble metal compounds such as platinum,
iridium, palladium, etc. Reference to such a method can
be made in the disclosures, for example, in U.S. Patent
No. 2,~88,060 and British Patent No. 618,061.
The core of the silver halide grain can be also doped
with a metallic ion. To dope the core with the metallic
ion, for example, the latter may be added in the form of
a water soluble salt of the metallic ion at any time in
the course of the formation of core grains. Preferable
examples for the metallic ion includes metallic ions such
as lead, antimony, bismuth, gold, osmium and rhodium.
These metallic ions may be used in concentration of 1 x
10 3 to 1 x 10 4 mol per mol of silver.
However, cores used as the core of the silver halide
grain may not be subjected to the above chemical sensi-
tization or doping with metallic ions. In such a case, a
sensitivity center is considered to be produced by, e.g.,
the formation of crystal distortlon at the interface
between the core and shell in the course the core parti-
cle is covered with the shell. Reference to this can be
30 made in the disclosures in U.S. Patents No. 3,935,014 and
No. 3,957,488.
In the above method for forming the shell on the core,
the double jet method or the pre-mixing method can be
used. Alternatively, the shell can be also formed by
mixing finely particulate silver halide into a core
emulsion, followed by Ostwald ripening.
- 9 ~ 1 31 7502
As mentioned above, the silver halide grain is formed
into a core/shell type, and also the surface composition
is controlled to contain silver chloride, so that the
fogging can be effectively carried out to increase the
maximum density of the resulting image and obtain a good
and stable image.
Further, an amount of the silver chloride in the silver
halide grain is not particularly limited and may be often
used silver halide grains containing a larger amount of
silver chloride depending upon the demand of shortage in
processing time. In the preferred embodiment, the amount
of the silver chloride is at least 50 mole %, more pre-
ferably 80 mole % or more based on the total amount of
the silver halide. In the o-ther preferred embodiment, if
a light-sensitive material containing silver halide
having much amount of silver chloride is combinedly used
with a heterocyclic compound having a mercapto group,
more excellent positive image can be obtained.
~s the heterocyclic compound having a mercapto group, the
following compound represented by the formula (I) is
preferred.
"Z~
C-SM (I)
N
wherein M represents a hydrogen atom, an alkali
metal atom, an ammonium group or a protective group
for a mercapto group; Z represents a group of non-
metallic atoms necessary for forming a heterocyclic
group, said heterocyclic group may have one or more
substituents or may be fused.
As the protective group for the mercapto group repre-
sented by M is a group forming a mercapto group by clea-
-10-~ 13~7502
vage in the presence of an alkali, and more specifically,
may include an acyl group, an alkoxycarbonyl group, an
alkylsulfonyl group, etc.
"-Z~
As the heterocyclic group represented byl C-, it may
have atoms as constituting rings such as a carbon atom, a
nitrogen atom, an oxygen atom, a sulfur atom, a selenium
atom, etc., and may be preferred a 5- to 6-membered ring.
Specific examples of the heterocyclic ring may include
imidazoler benzoimidazole, naphthoimidazole, thiazole,
thiazoline, benzothiazole, naphthothiazole, oxazole,
benzoxazole, naphthoxazole, selenazole, benzoselenazole,
naphthoselenazole, triazole, benzotriazole, tetrazole,
oxadiazole, thiadiazole, pyridine, pyrimidine, triazine,
purine, azaindene, etc.
As the substituent which may have been bonded to such
heterocyclic groups, there may be mentioned, for example,
a halogen atom, hydroxy, amino, nitro, mercapto, carboxy
and its salt, sulfo and its salts, alkyl, alkoxy, aryl,
aryloxy, alkylthio, arylthio, acylamino, sulfonamide,
carbamoyl, sulfamoyl, etc.
Of these compounds represented by the formula (I), parti-
cularly preferably employable compound can be shown by
the following formulae (II), (III) and (IV):
Rl Ar N ~ SH
N\ /N (II)
N
R ~ NZ/~ SH (III)
- 11 - 1 3 1 75 02
N - N
~ ~ (IV)
R3 z2 SM
In the formulae (II) to (IV), M has the same meaning as
in M oE the formula (I).
In the formula (II), Ar represents a phenyl group, a
naphthyl group or a cycloalkyl group; and Rl represents a
hydrogen atom or a substituent of Ar.
In the formula (III), zl represents an oxygen atom, a
sulfur atom, a selenium atom or a group -NH-; R2
represents a hydrogen atom or a substituent.
In the formula (IV), z2 represents an oxygen atom, a
sulfur atom, a selenium atom or a group -N- where R
represents a hydrogen atom, an alkyl group, an alkenyl
group, a cycloalkyl group, an aryl group, an aralkyl
group, -CoR5, --S02R5, -NHCOR6 or -NHS02R6; R5 represents
an alkyl group, an aryl group or amino group; R
represents an alkyl group~ a cycloalkyl group, an aryl
gropu or an aralkyl group); R3 represents a hydrogen
atom, an alkyl group, an alkenyl group, a cycloalkyl
group, an aryl group, an aralkyl group, a heterocyclic
group or an amino group.
In the following, representative examples of the com-
pounds represented by the formula (I) to be used in the
present invention (hereinafter referred to as the com-
pound of the present invention) are shown but the present
invention is not limited by these.
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(1) (2)
~y ~ SH HO--~N ~SH
~3)OCI~3 ( )
I~N ~ SH~aO3S--~N ~S~ a
(5) t6
(cH3)2N~N 11 SNH
N~N ~ CU 3CONU ~N'
t7) (8
~N SH C~N S~
~ so2~H h~ N~
(9) (lO)
~N S~l HOOG--~N~SH
CH3NHCONH ~=J N~--N ~ b~
(11) (12)
~N ~r SCOOGH 3 ~N ~rSH
. .
~ .
- 13 - 1 3 1 7502
(13) (14) H
~3N ~SII ~ ~SH
(1~) (16)
N a O ~ S )~
(17~ (18)
HOOC~ ~ ~S
(19) (20?
~ ~SH ~N
(21) (22)
~X ~SH ~
(23) (2~)
J~~ X
-14 ~ 1317502
(25) (~6)
~NS~ C2 H s ~ O JJ`SH
(27) N N (28) N--N
L~o)l~sl~ ~OJI~S~
(2~) (30)
H 2 N ~ S )l~SH ~ ~JI S J~SH
(31) (32?
CH~CONHJ~SJ~SH (t)C~Hs/l~S)l~SH
(33) (3~)
N---N ~ NJl`SH
(35) (36)
CH~CONN/I~N~SN CH~SOzNN/I~N~SN
-15- 1317502
(37) (38)
~ON~ SH N~
(~OCH 3 N
(39)
Cll 3~N ~N ~1
~ N--N
Sl~
The above compounds can be easily synthesized by the
15 already known method. For example, they can be obtained
in accordance with the method disclosed in U.S. Patent
No. 2,403,927 and No. 3,376,310, Japanese Unexamined
Patent Publication No. 59463/1980, or JournaI of the
Chemical Society, p. 4237 (1977), etc. Also, a part of
the compounds can be obtained as commercial products.
The above compounds can be added in the light-sensitive
material elements by dissolving in water or an organic
solvent having miscibility with water such as methanol,
25 acetone, etc. or by dissolving in a weak alkali or a weak
acid. An amount thereof may vary depending upon a kind
of the compounds to be used or a layer to be added, and
when it is added to a silver halide emulsion layer, the
amount is in the range of 10 6 to 10 3 mole, more prefer-
ably 10 5 to 10 3 mole per mole of ~ilver halide.
The compound of the present invention may be added, in
addition to the silver halide emulsion layer of the
light-sensitive material, to any layers of the consti-
tuent layers provided in the conventional light-sensitive
material such as a protective layer, an intermediate
layer, a filter layer, a halation preventive layer, a
- 16 - I 3 1 7 ~ 02
subbing layer, etc., but the silver halide emulsion layer
is particularly preferred.
The internal latent image type silver halide emulsion
used in this invention will be described below.
The internal latent image type silver halide emulsion
used in this invention can be used by overlapping emul-
sions having different sensitivities as emulsion layers
or mixing them in order to widen its exposure latitude.
In this instance, the proportion of the coated silver
amount in the respective emulsion layers can be arbitra-
rily determined depending on the photographic perfor-
mances required.
In the present invention, an internal latent image type
silver halide grain that has not preliminarily been
fogged can be used as the internal latent image type
silver halide grain. In this instance, what is meant by
the grain surface having not preliminarily been fogged is
that the density is not more than 0.6, preferably not
more than 0.4, obtained when a test piece produced by
coating the emulsion to be used on a transparent film
support so as to have 35 mgAg/cm2 is, without exposure to
light, developed for 10 minutes at 20C with use of sur-
face developing solution A shown below.
Surface developing solution A:
Metol 2.5 g
30 Q-Ascorbic acid 10 g
NaBO2 4H2O 35 g
KBr 1 g
Made up to 1 liter by adding water.
As the silver halide emulsion used in the silver halide
emulsion layer for the formation of the color positive
image in the light-sensitive material of this invention,
- 17 - 1 3 1 7 5 02
there can be preferably used an emulsion that can give
sufficient density when the test piece of the light-sen-
sitive material of this invention, containing the inter-
nal latent image type silver halide grain that has not
preliminarily been fogged and has been prepared in the
above manner, is exposed to light followed by developing
with use of internal developing solution B having the
formu]ation shown below.
10 Internal developing solution B:
Metol 2 g
Sodium sulfite (anhydrous) 90 g
Hydroquinone 8 g
Sodium carbonate (monohydrate) 52.5 g
15 KBr 5 g
KI 0.5 g
Made up to 1 liter by adding water.
To describe more specifically, it is an emulsion that can
show, when a part of the above test piece is exposed to
light through a luminous intensity scale over a certain
given period not longer than 1 second followed by devel-
oping for 10 minutes at 20C with use of Internal devel-
opment solution B, the denslty of at least 5 times, pre-
ferably at least 10 times, greater than that obtainedwhen another part of the test piece exposed to light
under the same conditions is developed for 10 minutes at
20C with use of Surface developing solution A.
The silver halide emulsion usable in working this inven-
tion can be chemically sensitized by use of a sensitizing
dye usually used. It is useful also for the silver
halide emulsion used in working this invention to use in
combination a sensitizing dye used in the supersensitiza-
tion of internal latent image type silver halide emul-
sions, negative silver halide emulsions, etc. Reference
to the sensitizing dye can be made in Research Disclo-
- 18 -~ 1 31 7502
sures No. 15162 and No. 17643.
To obtain a direct posi-tive image with use of the light-
sensitive material according to this invention, the
positive image can be readily obtained by carrying out
image exposure (or photographing) followed by surface
developing. Specifically, the principal steps for pro-
ducing the positive image comprise subjecting to image
exposure a light-sensitive photographic material having
an internal latent image type silver halide emulsion
layer that has not preliminarily been fogged, used in
this invention, and thereafter carrying out surface
developing after the processing for producing a fog
nucleus by chemical action or optical action, namely the
fogging, is carried out and/or in the course the fogging
is carried out. ~ere, the fogging can be carried out by
applying whole surface exposure or by using a compound
capable of producing a fog nucleus, i.e., a fogging
agent.
The whole surface exposure carried out in respect of the
light-sensitive photographic material of this invention
is carried out by dipping in, or wetting by, a developing
solution or other aqueous solution a light-sensitive
material subjected to image exposure, followed by wholly
and uniformly exposing it to light. As a light source
used here may be any light that is in the wavelength
region in which the above light-sensitive photographic
material can be sensitive to light. Alternatively, a
highly luminous light such as flash light can also be
irradiated, or a weak light may be irradiated for a long
time. The time for the whole surface exposure can be
varied in a wide range so as to finally obtain an optimum
positive image, depending on the above light-sensitive
photographic material, developing condition, and type of
the light source to be used. As for the amount of
exposure in the whole surface exposure, most preferred is
- 19 - 1317502
to apply an exposure amount of a certain given range in
the combination thereof with the light-sensitive materi-
al. Usually, an excessive exposure amount may cause
increase in minimum density or desensitization to lower
the image quality. However, employment of the light-sen-
sitive material of this invention ma~es it possible to
lessen the degree of image deterioration and obtain a
stable image.
A fogging agent that can be used in the processing in
which the light-sensitive photographic material of this
invention is chemically fogged will be described below.
As the fogging agent used in working this invention,
there can be used compounds of the types covering a wide
range. This fogging agent may be present at the time the
developing is carried out, and thus, for example, it may
be contained in a constituent layer, other than a
support, of the light-sensitive photographic material (in
particular, preferably in a silver halide emulsion
layer), or in the developing solution or a processing
solution precedent to the developing. It can be also
used in an amount varying in a wide range depending on
the purpose, and, when used by adding it in the silver
halide emulsion layer, in an amount of 1 to 1,500 mg,
preferably lO to l,000 mg, per mol of silver halide.
Also, when used by adding it in the processing solution
such as the developing solution, it can be added prefer-
ably in an amount of 0.01 to 5 g/liter, particularly pre-
ferably 0.05 to l g/liter.
The fogging agent used in this invention may include, for
example, the hydrazines described in U.S. Patents No.
2,563,785 and No. 2,588,982 or the hydrozide or hydrazine
compounds described in U.S. Patent No. 3,227,522; the
heterocyclic quaternary nitrogen chloride compounds des-
cribed in U.S. Patents No. 3,615,615, No. 3,718,479, No.
3,719,494, No. 3,734,738 and No. 3,759,901; and also a
- 20 - 131750~
compounds having a group adsorptive to the surface of
silver halide, such as the acylhydrazinophenylthioureas
described in ~.S. Patent No. 4,030,925. These fogging
agents can also be used in combination. For example,
Research Disclosure No. 15162 discloses a combined use of
a non-adsorptive fogging agent with an adsorptive fogging
agent. This technique for the combined use may be effec-
tive also in this invention. The fogging agent used in
this invention may be any of the adsorptive type or non-
adsorptive type, which also may be used in combination.
The developing agent that can be used in the surfacedeveloping solution used in the developing of the light-
sensitive photographic material of this invention may
include usual silver halide developing agents, for exam-
ple, polyhydroxybenzenes such as hydroquinone, amino-
phenols, 3-pyrazolidones, ascorbic acid and derivatives
thereof, reductones and phenylenediamines, or a mixture
o~ these. Specifically, it may include hydroquinone,
aminophenol, N-methylaminophenol, l-phenyl-3-pyrazoli-
done, l-phenyl-4,4-dimethyl-3-pyrazolidone, 1-phenyl-4-
methyl-4-hydroxymethyl-3-pyrazolidone, ascorbic acid,
N,N-diethyl-p-phenylenediamine, diethylamino-o-toluidine,
4-amino-3-methyl-N-ethyl-N-t~methanesulfonamidoethyl)anil
ine, 4-amino-3-methyl-N-ethyl-N-(~-hydroxyethyl)aniline,
etc. These developing agents may also be previously con-
tained in an emulsion so that it can be acted on silver
halide in the course the light-sensitive photographic
material is dipped in an aqueous solution having a high
pH.
~he developing solution used in this invention may fur-
ther contain a particular antifoggant and a developing
restrainer. It is also possible to incorporate these
additives for the developing solution in a constituent
layer of the light-sensitive photographic material in an
arbitrary fashion.
- 21 - l 3 1 7 5 02
In the case the light-sensitive photographic material of
this invention is actually used for full color photogra-
phy, at least one of each of a red-sensitive silver
halide emulsion layer, a green-sensitive silver halide
emulsion layer and a blue-sensitive silver halide emul-
sion layer is coated on a support as a photographic
constituent layer. Here, at least one layer of the
light-sensitive silver halide emulsion layers contains
the core/shell type grain comprising a core and a shell
covering said core, and also contain silver chloride as
the surface composition of the shell. Of course, all of
the light-sensitive silver halide emulsion layers may
preferably contain the internal latent image type silver
halide grain according to this invention. Also, each of
the light-sensitive silver halide emulsion layers may be
a same light-sensitive layer or may be separated into two
or more layers each having different sensitivity. In
such an instance, at least one of the same light-sensi-
tive layers each having different sensitivity may contain
the internal latent image type silver halide grain
according to this invention, but all of the emulsion
layers may preerably contain the internal latent image
type silver halide grain of this invention.
The color developing solution used in the light-sensitive
material of this invention will be described The color
developing solution contains l g/lit or less of a solvent
having a log P of 0.4 or more and having a low sulfite
ion concentration.
The above log P refers to a value determined from parti-
tion coefficient P of n-octanol/water. Value P can be
determined from the formula shown below.
Solute concentration in n-octanol Phase
P =
Solute concentration in aqueous phase
A logarithm of the value P thus determined refers to the
value log P, which value has been hitherto widely used in
- 22 - 1 31 75 02
the fields of agricultural chemicals and pharmaceuticals
as a measure for oil solubility. The value log P can be
known also from log PoCt in the table disclosed in Chemi-
cal Review, Vol. 71, No. 6, pp. 555-613, 1971. It also
can be theoretically determined according to the calcula-
tion method disclosed in Ecological Chemistry, Vol. 6,
pp. 3-11, but a found value may more preferably be used,
and a value observed by using n-octanol may particularly
more preferably be used.
The solvent having a log P of 0.4 or more, that is not
desired to be added in the developing solution used in
the light-sensitive material of this invention, includes
aliphatic alcohols, aliphatic glycol ethers, alicyclic
alcohols or aromatic alcohols, and, among these, particu-
larly those having 5 to 20 carbon atoms.
Specific examples thereof may include;
Benzyl alcohol log P 1.0
20 o-Hydroxybenzyl alcohol log P 0.73
Cyclohexanol log P 1.23
2-Benzyloxyethanol log P 0.41
Anisyl alcohol log P 0.70
l-Pentanol log P 0.4 or more
25 Phenylethyl alcohol log P 1.36
p~Tolylcarbinol log P 1.36
Phenol log P 0.4 or more
p-Hydroxybenzyl alcohol log P 0.4 or more
Benzylamine log P 0.4 or more
30 Diethylene glycol monobutyl ether log P 0.41.
The above solvents are, as mentioned above, compounds
that may accelerate the coupling reaction of an oxidized
product of a color developing agent with a coupler in the
light-sensitive material, and the content thereof is con-
trolled to 1 g/lit or less. By controlling it to such a
low concentration, BOD or COD values can be suppressed to
- 23 ~ 1 3 1 7 5 02
low values even when the above color developing solution
having been deteriorated is thrown away, and there can be
provided an effective countermeasure for environmental
pollution. Moreover, by controlling the concentration of
the sulfite ions serving as a preservative to a lower
concentration, it is intended to restrain the reaction
with the above solvent to enhance the coupling reaction
in the color development processing. What is meant by
"having a low sulfite ion concentration" in this inven-
tion is that the sulfite ions is in such a concentrationthat they can serve as a preservative and at the same
time can suppress the reaction with the above solvent
having a log P of 0.4 or more, so as not to inhibit the
coupling reaction in the color developing solution.
Thus, the concentration may preferably be 2.0 x 10 2 mole
or less, more preferably about 1.0 x 10 2 mole, per liter
of the color developing solution.
Since the coupling reaction can be effectively carried
out by controlling the sulfite ion concentration to a
lower concentration as mentioned above, it is possible to
make higher the maximum density of the color image color-
developed by the above color developing solution, and to
obtain a good image.
In addltion, conjointly with the employment of the core/
shell grain containing silver chloride in the surface
composition of the internal latent image type silver
halide grain, it is possible to obtain a light-sensitive
material that can be stable in the processing and can
have a good image quality.
This invention will be described below specifically by
giving Examples. However, as a matter of course, the
embodiments of this invention are by no means limited to
Examples shown below.
- 24 - 1317502
Example 1
An aqueous solution of silver nitrate and an aqueous
solution of potassium bromide in equimolar amounts were
simultaneously added over a period of about 40 minutes at
50C according to the controlled double jet method, to
obtain a tetradecahedral silver bromide emulsion having
an average grain size of 0.4 ~m. However, 5 minutes
after the addition of the aqueous solution of silver
nitrate and the aqueous solution of potassium bromide was
started, potassium hexachloroiridate was added in an
amount of 0.02 mg per mol of silver. To the emulsion
thus obtained, sodium thiosulfate was added in an amount
of 2.0 mg per mol of silver, followed by chemical sensi-
tization for 60 minutes at 60 C to obtain emulsion A.
Using this emulsion A for the formation of core grains,core/shell emulsions B to E shown below were obtained.
Emulsion B:
Using emulsion ~ for the formation of core grains,
an aque.ous solution of silver nitrate and an aqueous
solution of potassium bromide were further simultaneously
added to obtain a tetradecahedral core/shell emulsion
having an average grain size of 0.6 ~m.
Emulsion C:
Using emulsion A for the formation of core grains,
an aqueous solution of silver nitrate and an aqueous
solution of potassium bromide were further simultaneously
added to be grown up to grains of 0.5 ~m, and successive-
ly an aqueous solution of silver nitrate and an aqueous
solution of sodium chloride were further simultaneously
added to obtain a cubic core/shell emulsion having an
average grain size of 0.6 ~m.
1311502
- 25 -
Emulsion D:
Core/shell emulsion D was obtained in substantially
the same manner as for the above emulsion C. This emul-
sion D, however, was prepared by adding an aqueous
solution containing potassium bromide and sodium chloride
(KBr : NaCl = 1 : 3 in molar ratio) in place of the
aqueous ~olution of sodium chloride.
Emulsion E:
Core/shell emulsion E was obtained in substantially
the same manner as for the above emulsion C. This emul-
sion E, however, was prepared by adding an aqueous
solution containing potassium bromide and sodium chloride
(KBr : NaCl = 1 : 1 in molar ratio) in place of the
a~ueous solution oE sodium chloride.
Emulsion F:
Core/shell emulsion F was obtained in substantially
the same manner as for the above emulsion C. This emul-
sio~ F, however, was prepared by adding an aqueoussolution containing potas9ium bromide and sodium chloride
(KBr : NaCl = 3 : 1 in molar ratio) in place of sodium
chloride.
To each of emulsions B to F obtained in the above, added
was a dispersion obtained by dissolving a sensitizing dye
sodium 5,5'-diphenyl-9-ethyl-3,3'-disulfopropyloxycarbo-
cyanate and a magenta coupler 1-(2,4,6-trichlorophenyl)-
3-(2-chloro-5-octadecylsuccinimidoanilino)-5-pyrazolone
in a solvent, followed by emulsification dispersion in an
aqueous gelatin solution, to which a hardening agent was
further added. The resulting emulsion was coated on a
resin-coated paper support to have a coated silver amount
of 4 mg/100 cm2, followed by drying to obtain samples No.
1 to No. 5.
Each of these samples was subjected to wedge exposure
- 26 - 1 31 75 02
through a yellow filter, followed by developing for 3
minutes at 38C with use of the developing solution
formulated as follows.
5 4-Amino-3-methyl-N-ethyl-N-(~-methane-
sulfonamidoethyl)aniline sulfate 5 g
Sodium sulfite (anhydrous) 1 x 10 2 M/lit
Sodium carbonate (monohydrate) 15 g
Potassium bromide 0.6 g
10 Made up to 1 liter by adding water
(Adjusted to pH 10.2 with use of potassium hydroxide.)
For 20 seconds after 20 seconds from the starting of the
developingr however, the whole surface was uniformly
exposed to light by use of white light and with the
exposure amount as shown ln Table 1 belowr followed by
bleach-fixing and washing according to a conventional
manner r and drying. Thereafter, samples No. 1 to No. 5
wer-e developed under the same conditions as those des-
cribed above except that the concentration of sodiumsulfite in the color developing solution was controlled
to 0.03 M/lit.
As will be clear from the results shown in Table 1, it is
understood that silver chloride may be contained in the
surface composition of the outermost layer of the core/
shell grain according to this invention, so that the
maximum density can be remarkably improved and there can
be obtained a good positive image stable also to the
change in the fogging exposure amount.
It is also understood that the maximum density of the
resulting image is abruptly lowered when the sulfite ion
concentration in the color developing solution is made to
vary from 1 x 10 which is the low concentration as
mentioned in this invent1on to 3 x 10 2 which is not the
low concentration.
- 27 _ 1 3 1 7 5 02
It is therefore understood that in the light-sensitive
material of this invention, an image having a high
maximum density can be obtained when the sulfite ion
concentration is controlled to the range of the low
concentration.
1317502
- 28 -
Y a) ,o .~o ~o ,~, ~3 ~ a) ~ a)
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- 29 - t 3 ~ 7 5 0~
Example 2
-
An aqueous solution of silver nitrate and an aqueous
solution of ~otassium bromide in equimolar amounts were
simultaneously added at 50C and mixed to obtain a tetra-
decahedral silver bromide emulsion G having an average
grain size of 0.4 ~m.
Using this emulsion G for the formation of core grains,
there were obtained core/shell emulsions ~ to L as shown
below.
Emulsion H:
Using emulsion G for the formation of core grains,
an aqueous solution of silver nitrate and an aqueous
solution of potassium bromide were further simultaneously
added to obtain a tetradecahedral core/shell emulsion
having an average grain size of 0.6 ~m.
Emulsion I:
Using emulsion G for the formation of core grains,
an aqueous solution of silver nitrate and an aqueous
solution of sodium chloride were simultaneously added to
obtain a cubic core/shell emulsion having an average
grain size of 0.6 ~m.
Emulsion J:
Core/shell emulsion J was obtained ln substantially
the same manner as for the above emulsion I. This emul-
sion J, however, was prepared by adding an aqueoussolution containing potassium bromide and sodium chloride
(KBr : NaCl = 1 : 4 in molar ratio) in place of the
aqueous solution of sodium chloride.
Emulsion K:
Core/shell emulsion K was obtained in substantially
the same manner as for the above emulsion I. This emul- -
- 30 - ~317502
sion K, however, was prepared by adding an aqueous
solution containing potassium bromide and sodium chloride
(KBr : NaCl = 1 : 1 in molar ratio) in place of the
aqueous solution of sodium chloride.
Emulsion L:
Core/shell emulsion L was obtained in substantially
the same manner as for the above emulsion I. This emul-
sion L, however, was prepared by adding an aqueous
solution containing potassium bromide and sodium chloride
(KBr : NaCl = 4 : 1 in molar ratio) in place of sodium
chloride.
To each of the above emulsions H to L, the sensitizing
dye represented by the formula shown below was added.
2 0 ~ ¦ C 2 H s ~3
(CHz) sSO3~1a .
(CH2) 3S03e
Also prepared was an emulsified solution obtained by
dispersing 2,4 dichloro-3-methyl-6-[~-(2,4-di-tert-amyl-
phenoxy)butylamido)phenol as a cyan coupler in dibutyl
phthalate and ethyl acetate and dispersed in an aqueous
gelatin solution.
Next, this emulsified dispersion was added and mixed in
each emulsion to which the above sensitizing dye was
added, to which a hardening agent was added. The result-
ing emulsion was coated on a resin-coated paper support
to have a coated silver amount of 5.0 mg/100 cm2,
followed by drying to obtain samples No. 6 to No. 10.
Each of these samples was subjected to wedge exposure
- 1317502
through a yellow filter, followed by developing for 3
minutes at 38C with use of the developing solution
formulated as follows.
5 4-Amino-3-methyl-N-ethyl-N-(~-methane-
sulfonamidoethyl)aniline sulfate 5.0 g
Sodium sulfite (anhydrous) 6 x 10 3 M/lit
Potassium carbonate 20 g
Potassium bromide 0.5 g
10 Ben~yl alcohol 0.6 g
~-Acetyl-phenylhydrozine (fogging agent)
in the amount as shown in Table 2
Made up to 1 liter by adding water
(Adjusted to pH 12.0 with use of potassium hydroxide.)
Subsequently, bleach~fixing and washing was carried out
according to a conventional manner, followed by drying.
On each sample thus obtained, the maximum density and
minimum density of a cyan positive image were measured to
obtain the results as shown in Table 2 below.
As will be clear from the results shown in Table 2, it is
understood that silver chloride may be contained in the
surface composition of the outermost layer of the
core/shell grain according to this invention, so that the
maximum density can be remarkably improved and a good
positive image showing a high maximum density can be
stably obtained even with varied concentration of fogging
agent.
-32- 1317502
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- 33 - 1 31 750~
Exam~le 3
An aqueous solution of silver nitrate and an aqueous
solution of potassium bromide in equimolar amounts were
simultaneously added at 50 C and mixed to obtain a cubic
silver bromide emulsion M having an average grain size of
0.2 ~m.
Using this emulsion M for the formation of core grains,
an aqueous solution of silver nitrate and an aqueous
solution of potassium G~loride were further simultaneously
added to obtain a cubic core/shell emulsion N having an
average grain size of 0.7 ~m (silver chloride content: 98
: mole %).
To the above emulsion N, an emulsified solution prepared
by dissolving ~-[4-(1-benzyl-2-~henyl-3,5-dioxo-1,2,4-
triaæolidinyl)]-~-pyvalyl-2-chloro-5-[~-(2,4-di-te~t-amyl-
phenoxy)butyramido]acetanilide as a yellow coupler in a
solvent and dispersing in an aqueous gelatin solution was
added. Then, a hardening agent was added to the emulsion
to which the above sensitizing dye was added. The
resulting emulsion was coated on a resin-coated paper
support to have a coated silver amount of 6 mgjlOO cm2,
followed by drying to obtain sample No. 11.
,
Also, samples No. 12 and No. 13 were prepared in the same
manner as in sample No. 11 e~cept for adding a hetero-
cyclic mercapto compound (3) described hereinbefore.
Each of these samples was subjected to wedge exposure,
followed by developing for 1 minute at 38C with use of
the developing solution formulated as follows.
4-Amino-3-methyl-N-ethyl-N-(~-methane-
sulfonamidoethyl)aniline sulfate 5 g
Triethanolamine 8 ml
. ~
1 3 1 750~
N,N-Diethylhydroxylamine 4 ml
Sodium sulfite (anhydrous) 0.15 g
Sodium chloride 2 g
Sodium carbonate 15 g
5 Made up to 1 liter by adding water
(Adjusted to pH 10.2 with use oE sodium hydroxide.)
For 5 seconds after 10 seconds from the starting of the
developing, however, the whole surface was uniformly
exposed to light by use of white light and with the
exposure amount as shown in Table 3 below, followed by
bleach-fixing and washing according to a conventional
manner, and drying.
As will be clear from the results shown in Table 3, it is
understood that by processing the light-sensitive materi-
al containing the emulsion N of the core/shell grain
according to the present invention with the above color
developing solution containing no benzyl alcohol and
having low sulfite ion concentration, a good positive
image can be stably obtained even with varied concentra-
tion of fogging agent (sample No. 11). Also, by using
the heterocyclic mercapto compound, a positive image can
further be improved since the minimum density i5 res-
trained (sample No. 12). However, as disclosed in Japan-
ese Patent Publication No. 12709/1970 (which corresponds
to U.S. Patent No. 3,733,198), when the heterocyclic
compound is used with a large amount (sample No. 13), the
maximum density is lowered while the effect of the
present invention can be obtained.
1 31 7502
-- 35 -- .
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- 36 ~ 1 3 ~ 75 02
As described in the above, it is possible according to
this invention to afford an internal latent image type
light-sensitive silver halide photographic material that
can show a higher maximum density of the positive image
formed by the color developing, and can be stable also to
the variation in the fogging conditions.
It is also possible to obtain an internal latent .image
type light-sensitive silver halide photographic material
that can obtain an image of qood quality as mentioned
above even when processed by use of processing solutions
havlng a small environmental load such as ~OD and COD.
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