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Description  |
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FIELD OF THE INVENTION
This invention relates to a silver halide light-sensitive material and,
more particularly, to a silver halide light-sensitive material which shows
both an improved graininess and a raised sensitivity. More specifically,
it relates to the light-sensitive material as described above obtained by
employing a novel layer structure.
BACKGROUND OF THE INVENTION
Many techniques have heretofore been known for raising sensitivity of
silver halide light-sensitive materials. However, all of them involve such
defects as deterioration in graininess of image and increase in fog. Thus,
techniques for raising sensitivity without such defects have been desired.
An example of raising sensitivity by devising a new layer structure for the
light-sensitive material includes a technique of comprising a fine
particle reflecting layer being positioned under and adjacent to an
emulsion layer to raise the sensitivity of the emulsion layer by utilizing
light-scattering properties of the fine particle reflecting layer. This
technique is disclosed in Research Disclosure No. 134 (1975), p. 47,
13452.
This technique is surely effective for raising sensitivity, but sometimes
it remarkably deteriorates graininess so much that it causes difficult
problems when practised.
SUMMARY OF THE INVENTION
An object of the present invention is to eliminate the deterioration in
graininess caused by raising sensitivity. That is, a main object of the
present invention is to provide a light-sensitive material which shows
both a raised sensitivity and an improved graininess.
The above-described object of the present invention is attained by a silver
halide light-sensitive material comprising a support comprising thereon at
least two emulsion layers having the same color sensitivity and being
different in sensitivity, with a layer containing comparatively
light-insensitive silver halide grains of 0.05 to 0.6 .mu.m in average
grain size being positioned in at least one of interspaces defined by
every two adjacent members of said at least two emulsion layers.
DETAILED DESCRIPTION OF THE INVENTION
The layer structure of the present invention raises the sensitivity of the
further emulsion layer of the two light-sensitive emulsion layers adjacent
to a certain light-insensitive silver halide grains-containing layer from
the support and improves graininess of the image for which the two
light-sensitive emulsion layers adjacent to the light-insensitive silver
halide grain-containing layers are responsible in spite of the increase in
sensitivity.
This improvement is entirely unexpected if taking into consideration the
fact that, when a comparatively light-insensitive silver halide layer is
provided adjacent to and under a least-sensitive emulsion layer, both a
raised sensitivity and a deteriorated graininess result.
In the practice of the present invention, the same effects can be obtained
both in the case of viewing a silver image as it is and in the case of
forming a color image in conformity with the silver image utilizing a
coupling reaction or the like.
The light-sensitive material of the present invention preferably contains
couplers in emulsion layers. With such light-sensitive materials, one or
more emulsion layers having different color sensitivities may be provided
for obtaining a color image.
When the layer structure of the present invention is applied to the silver
halide light-sensitive material comprising a support comprising thereon at
least two emulsion layers having the same color sensitivity and being
different in sensitivity with no layer being different in color
sensitivity from said at least two emulsion layers being positioned in at
least one of interspaces defined in every two adjacent members of said at
least two emulsion layers, the effects of the present invention are
remarkably obtained. When the layer structure of the present invention is
applied to the silver halide light-sensitive color photographic material
comprising a support comprising thereon a red-sensitive silver halide
emulsion layer unit, a green-sensitive silver halide emulsion layer unit
and a blue-sensitive silver halide emulsion layer unit in this order, said
every color-sensitive silver halide emulsion layer unit comprising at
least two emulsion layers having the same color sensitivity and being
different in sensitivity therein, such effects as both an improved
graininess and a raised sensitivity are particularly remarkably obtained.
In the present invention, the total number of emulsion layers having the
same color sensitivity as that of two emulsion layers adjacent to the
comparatively light-insensitive silver halide layer may be two or more,
with two or three being preferable. With light-sensitive materials having
three or more such emulsion layers, the light-insensitive layer may be
provided between every two adjacent emulsion layers (in this case, the
number of the light-insensitive silver halide layer being maximum). The
objects of the present invention can be attained by providing at least one
light-insensitive silver halide layer. A proper number between one and the
maximum number of the light-insensitive silver halide layers may be
provided based on the architecture of a light-sensitive material.
In the silver halide light-sensitive material comprising a support
comprising thereon at least three emulsion layers having the same color
sensitivity and being different in sensitivity, when the fine grain
reflecting layer is provided adjacent to and under the emulsion layer
having the fastest sensitivity of said at least three emulsion layer, such
effect as both an improved graininess and raised sensitivity are
remarkably obtained.
The light-insensitive emulsion layer is effective to some extent when it
contains a coupler. However, when it contains no couplers, a particularly
high sensitivity and a good graininess are attained, which is entirely
unexpected.
The comparatively light-insensitive silver halide grains-containing layer
of the present invention should have a sensitivity which is so low that it
does not substantially contribute to the developed image. The layer may
comprise a small amount of silver halide grains with high sensitivity,
provided the total resulting sensitivity of this layer is so low that it
does not contribute to the resulting image. However, the use of such a
layer containing a small amount of sensitive grains may result in somewhat
insufficient effects.
The comparatively light-insensitive silver halide emulsion layer of the
present invention must have a sensitivity lower than the least sensitive
layer of said at least two light-sensitive silver halide emulsion layers
of the same color sensitivity by 0.5 or more, preferably, 1.0 or more, in
log units.
The comparatively light-insensitive silver halide emulsion of the present
invention may be any of pure silver chloride, pure silver bromide, pure
silver iodide, silver chlorobromide, silver iodobromide, and silver
chloroiodobromide. An emulsion containing 60% or more silver bromide, 30%
or less silver chloride, and 40% or less silver iodide is preferable.
Grain size of the silver halide is not particularly limited, but a
preferable size is 0.6 .mu.m or less, more preferably 0.08 to 0.4 .mu.m.
Where the light-insensitive silver halide emulsion-containing layer is
provided between blue-sensitive emulsion layers, the size preferably
ranges from 0.08 to 0.25 .mu.m. Where the layer is provided between
green-sensitive emulsion layers, the size preferably ranges from 0.1 to
0.3 .mu.m and, where provided between red-sensitive emulsion layers, the
size preferably ranges from 0.1 to 0.4 .mu.m. The comparatively
light-insensitive silver halide emulsion to be used in the present
invention may have a comparatively broad grain size distribution, but
preferably has a narrow grain size distribution. In particular, 90% by
weight or number of silver halide grains preferably have sizes falling
within .+-.40% of an average grain size.
In the silver halide light-sensitive color photographic material comprising
a support comprising thereon a red-sensitive silver halide emulsion layer
unit, a green-sensitive silver halide emulsion layer unit and a
blue-sensitive silver halide emulsion layer unit, wherein said
blue-sensitive silver halide emulsion layer unit comprises at least two
emulsion layers having the same color sensitivity and being different in
sensitivity therein, when the fine grain reflecting layer is provided in
at least one of interfaces defined by every two adjacent members of said
at least two emulsion layers in said blue-sensitive silver halide emulsion
layer unit, the effects of the present invention are remarkably obtained.
In the silver halide light-sensitive color photographic material
comprising a support comprising thereon a red-sensitive silver halide
emulsion layer unit, a green-sensitive silver halide emulsion layer unit
and a blue-sensitive silver halide emulsion layer unit, wherein said
blue-sensitive silver halide emulsion layer unit comprises three emulsion
layers having the same color sensitivity and being different in
sensitivity therein, when the fine grain reflecting layer is provided
adjacent to and under the emulsion layer having the fastest sensitivity of
said three emulsion layer, the effects of the present invention are more
remarkably obtained. When the fine grain reflecting layer which provides
adjacent to and under the emulsion layer having the fastest sensitivity of
said three emulsion layer comprised in the blue-sensitive silver halide
emulsion layer unit comprises comparatively light-insensitive silver
halide grains of 0.08 to 0.25 .mu.m in average grain size, the effects of
the present invention are particularly remarkably obtained.
The comparatively light-insensitive emulsion layer is coated in a silver
amount of 0.03 to 5 g/m.sup.2, preferably 0.05 to 1 g/m.sup.2. The binder
for the comparatively light-insensitive layer may be any hydrophilic
polymer, with gelatin being preferable. The binder is preferably used in
an amount of less than 250 g per mol of silver halide.
The comparatively light-insensitive silver halide to be used in the present
invention can be prepared according to known processes, i.e., by any of an
acid process, a neutral process, and an ammonia process. Reacting the
soluble silver salt with a soluble halide salt may be carried out by any
one of single jet mixing, double jet mixing, and combination thereof. A
double jet mixing process which involves maintaining the pAg in a liquid
phase in which silver halide is produced at a definite level, so-called
the controlled double jet process, can be employed. This process provides
a narrow grain size distribution, thus being preferable as a process for
preparing the comparatively light-insensitive emulsion of the present
invention. The grains in the comparatively light-insensitive emulsion may
be in a regular crystal form such as cubic, octahedral, dodecahedral or
tetradecahedral form or in an irregular crystal form such as spherical or
tabular form. The silver halide grains may have an inner portion and a
surface layer different form, or the same as, each other in halogen
composition. The comparatively light-insensitive emulsion may contain
cadmium ion, lead ion, iridium ion, rhodium ion, etc. as impurities. The
comparatively light-insensitive emulsion may be of the type which involves
forming latent images on the surface of grains or of the type which
involves forming latent images within them, with the inner portion of the
grains optionally containing fogging nuclei.
The comparatively light-insensitive emulsion may be subjected to ordinary
chemical sensitization, i.e., sulfur sensitization, gold sensitization,
and reduction sensitization. However, the degree of the chemical
sensitization is desirably minimized. Emulsions not subjected to chemical
sensitization (so-called primitive emulsions) are preferable used as the
emulsions of the present invention.
The comparatively light-insensitive emulsion may contain a cyanine dye, a
merocyanine dye, a complex cyanine dye, a complex merocyanine dye, a
holopolar cyanine dye, a hemicyanine dye, a styrene dye, a hemioxonol dye,
etc. Desensitizing dyes not preferable in ordinary negative emulsions due
to large desensitization effect can be used as well. The comparatively
light-insensitive emulsion may contain an antifogging agent and a
stabilizing agent. For example, such antifogging or stabilizing agents as
azoles, hetero ring mercapto compounds, thioketo compounds, azaindenes,
benzenethiosulfonic acids, benzenesulfinic acids, etc. can be added.
The comparatively light-insensitive emulsion layer of the present invention
may contain dyes and a dispersion of scarcely soluble synthetic polymer.
Silver halide emulsions to be used in the present invention are usually
prepared by mixing a solution of a water-soluble silver salt (e.g., silver
nitrate) with a solution of a water-soluble halide (e.g., potassium
bromide) in the presence of a solution of a water-soluble high polymer
such as gelatin. As the silver halides, mixed silver halides such as
silver chlorobromide, silver iodobromide, silver chlorobromoiodide, etc.
can be used as well as silver chloride and silver bromide. The silver
halide grains preferably have an average particle size (particle diameter
with respect to spherical or approximately spherical particles, and edge
length with cubic particles; presented in terms of an average based on
projected area) of 3 .mu.m or less. Particle size distribution can be
either narrow or broad.
The silver halide grains may be in a cubic or octahedral form or in a mixed
form thereof. Further, separately prepared two or more silver halide
photographic emulsions may be mixed for use.
The silver halide grains may have a uniform crystal structure of a layered
structure in which the inner portion and the outer portion have different
properties, or may be of so-called conversion type as described in British
Pat. No. 635,841 and U.S. Pat. No. 3,622,318. In addition, they may be of
the type forming a latent image mainly on the surface thereof or of the
type forming a latent image within the grains. These photographic
emulsions are also described in such books as Mees; The Theory of
Photographic Process (published by Macmillan), P. Glafkides; Chimie
Photographique (published by Paul Montel in 1957), etc. and are generally
accepted.
The photographic emulsion to be used in the present invention can be
prepared by the processes described in P. Glafkides; Chimie et Physique
Photographique (published by Paul Montel in 1967), G. F. Duffin;
Photographic Emulsion Chemistry (published by The Focal Press in 1966), V.
L. Zelikman et al; Making and Coating Photographic Emulsion (published by
The Focal Press in 1964), and the like. That is, any of an acid process, a
neutral process, and an ammonia process can be used. As a manner of
reacting a soluble silver salt with a soluble halide salt, any of single
jet mixing, double jet mixing, and their combination may be employed.
A process of forming grains in the presence of excess silver ion (so-called
reversal mixing process) can be employed as well. A useful type of double
jet mixing process is the controlled double jet process wherein pAg in a
liquid phase in which silver halide is formed is kept constant. This
process provides a silver halide emulsion containing silver halide grains
having a regular crystal form and an approximately uniform particle size.
Two or more silver halide emulsions having been separately prepared may be
mixed for use.
During formation or physical ripening of silver halide grains, cadmium
salts, zinc salts, lead salts, thallium salts, iridium salts or the
complex salts thereof, rhodium salts or the complex salts thereof, iron
salts or the complex salts thereof, etc. may be allowed to coexist.
Soluble salts may be removed from the emulsion after forming precipitates
or physical ripening, by methods such as a noddle washing method of
gelling gelatin or a flocculation method utilizing an inorganic salt
composed of a multivalent anion (e.g., sodium sulfate), an anionic
surfactant, an anionic polymer (e.g., polystyrenesulfonic acid) or a
gelatin derivative (e.g., aliphatically or aromatically acylated gelatin,
aromatically carbamoylated gelatin, etc.). The stop of removeing the
soluble salts may be omitted.
The silver halide emulsion may be used without chemical sensitization as
so-called primitive emulsion, but is usually chemically sensitized.
Chemical sensitization can be conducted according to the processes
described in the foregoing books written by Glafkides, Zelikman, etc. or
in H. Frieser; Die Grundlagender Photographischen Prozesse mit
Silberhalogeniden (AkademischeVerlagsgesellschaft, 1968).
As a binder or protective colloid to be used in the emulsion layer or
interlayer of the light-sensitive material of the present invention,
gelatin is advantageously used. However, other hydrophilic colloids can be
used as well. For example, proteins such as gelatin derivatives, graft
polymers between gelatin and other high polymer, albumin, casein, etc.;
cellulose derivatives such as hydroxyethyl cellulose, carboxymethyl
cellulose, cellulose sulfate, etc.; sugar derivatives such as sodium
alginate, starch derivative, etc.; and various synthetic hydrophilic
substances such as homopolymers or copolymers (e.g., polyvinyl alcohol,
partially acetallized polyvinyl alcohol, poly-N-vinylpyrrolidone,
polyacrylic acid, polymethacrylic acid, polyacrylamide, polyvinyl
imidazole, polyvinyl pyrazole, etc.) can be used.
As gelatin, acid-processed gelatin or enzyme-processed gelatin as described
in Bull. Soc. Sci. Photo. Japan, No. 16, p. 30 (1966) may be used as well
as lime-processed gelatin, and a gelatin hydrolyzate or an
enzyme-decomposed product can be used. As the gelatin derivatives, those
obtained by reacting gelatin with, for example, acid halides, acid
anhydrides, isocyanate, bromoacetic acid, alkanesultones,
vinylsulfonamides, maleinimide compounds, polyalkylene oxides, epoxy
compounds, or the like can be used. Specific examples thereof are
described in U.S. Pat. Nos. 2,614,928, 3,132,945, 3,186,846, 3,312,553,
British Pat. Nos. 861,414, 1,033,189, 1,005,784, Japanese Patent
Publication No. 26845/67, etc.
As the aforesaid gelatin graft polymers, products prepared by grafting to
gelatin a homopolymer or copolymer of vinyl monomer such as acrylic acid,
methacrylic acid, ester or amide thereof, acrylonitrile, styrene, or the
like can be used. In particular, graft polymers between gelatin and a
polymer having some compatibility with gelatin such as a polymer of
acrylic acid, methacrylic acid, acrylaminde, methacrylamide, hydroxyalkyl
methacrylate or the like are preferable. Examples of these are described
in U.S. Pat. Nos. 2,763,625, 2,831,767, 2,956,884, etc.
In the present invention, couplers may be used. Usable couplers include the
following dye-forming couplers; i.e., compounds capable of forming color
by oxidative coupling with an aromatic primary amine developing agent
(e.g., a phenylenediamine derivative or an aminophenol derivative) during
color development. For example, magenta couplers include 5-pyrazolone
couplers, pyrazolobenzimidazole couplers, cyanoacetylcoumarone couplers,
open-chain acylacetonitrile couplers, etc., yellow couplers include
acylacetamide couplers (e.g., benzolyacetanilides, pivaloylacetanilides,
etc.), etc., and cyan couplers include naphthol couplers, phenol couplers,
etc. Of these couplers, non-diffusion couplers having a hydrophobic group
called ballast group or being converted to polymers are desirable. The
couplers may be of either 4-equivalent type or 2-equivalent type with
respect to silver ions. In addition, they may be colored couplers having a
color-correcting effect or couplers capable of releasing a development
inhibitor upon development (called DIR couplers).
In addition to DIR couplers, the colorless DIR coupling compounds which
release a development inhibitor and form a colorless coupling reaction
product may be incorporated.
In order to obtain properties required for light-sensitive material, two or
more of the above-described couplers may be used in one and the same
layer, or one and the same compound thereof may of course be incorporated
in two or more different layers.
Introduction of the couplers into silver halide emulsion layers is
conducted in a known manner, for example, according to the method
described in U.S. Pat. No. 2,332,027. For example, the couplers are
dissolved in an organic solvent having a high boiling point such as an
alkyl phthalate (e.g., dibutyl phthalate, dioctyl phthalate, etc.), a
phosphoric ester (e.g., diphenyl phosphate, triphenyl phosphate, tricresyl
phosphate, dioctylbutyl phosphate, etc.), a citric acid ester (e.g.,
tributyl acetylcitrate), a benzoic ester (e.g., octyl benzoate), an
alkylamide (e.g., diethyllaurylamide), a fatty acid ester (e.g.,
dibutoxyethyl succinate, diethyl azelate, etc.), a trimesic acid ester
(e.g., tributyl trimesate), etc. or in an organic solvent having a boiling
point of about 30.degree. to 150.degree. C. (e.g., lower alkyl acetate
such as ethyl acetate or butyl acetate, ethyl propionate, tert-butyl
alcohol, methyl isobutyl ketone, .beta.-ethoxyethyl acetate, methyl
cellosolve acetate or the like, and dispersed in a hydrophilic colloid.
The above-described high-boiling organic solvents and the low-boiling
organic solvents may be used in combination.
In addition, a dispersing method using a polymer described in Japanese
Patent Publication No. 39853/76 and Japanese Patent Application (OPI) No.
59943/76 can be used.
Couplers with an acid group such as a carboxylic acid or a sulfonic acid
are introduced into a hydrophilic colloid as an alkaline aqueous solution.
Photographic color-forming agents to be used are conveniently selected so
that they provide an intermediate scale image. The maximum absorption band
of a cyan dye formed from the cyan color-forming agent preferably lies
between about 600 and about 720 nm, that of a magenta dye between about
500 and about 580 nm, and that of a yellow dye between about 400 and about
480 nm.
The photographic emulsion to be used in the present invention may be
spectrally sensitized with methine dyes or the like. Usable dyes include
cyanine dyes, merocyanine dyes, complex cyanine dyes, complex merocyanine
dyes, holopolar cyanine dyes, hemicyanine dyes, styryl dyes, and
hemioxonol dyes. Particulaly useful dyes are those which belong to cyanine
dyes, merocyanine dyes, and complex merocyanine dyes. In these dyes, any
of nuclei ordinarily used as basic hetero ring nuclei in cyanine dyes can
be used. That is, a pyrroline nucleus, an oxazole nucleus, a thiazoline
nucleus, a pyrrole nucleus, an oxazole nucleus, a thiazole nucleus, a
selenazole nucleus, an imidazole nucleus, a tetrazole nucleus, a pyridine
nucleus, etc.; those in which these nuclei are fused with an alicyclic
hydrocarbon ring; those in which these nuclei are fused with an aromatic
hydrocarbon ring, e.g., an indolenine nucleus, a benzimdolenine nucleus,
an indole nucleus, a benzoxazole nucleus, a naphthoxazole nucleus, a
benzothiazole nucleus, a naphthothiazole nucleus, a benzoselneazole
nucleus, a benzimidazole nucleus, a quinoline nucleus, etc. can be used.
These nuclei may be substituted in the nuclear carbon atom.
In the merocyanine dyes or complex merocyanine dyes, 5- or 6-membered
hetero ring nuclei such as a pyrazolin-5-one nucleus, a thiohydantoin
nucleus, a 2-thiooxazolidin-2,4-dione nucleus, a thiazolidine-2,4-dione
nucleus, a rhodanine nucleus, a thiobarbituric acid nucleus, etc. may be
used as ketomethylene structure-containing nuclei.
Useful sensitizing dyes include, for example, those described in German
Pat. No. 929,080, U.S. Pat. Nos. 2,231,658, 2,493,748, 2,503,776,
2,519,001, 2,912,329, 3,656,959, 3,672,897, 3,694,217, 4,025,349,
4,046,572, British Pat. No. 1,242,588, Japanese Patent Publication Nos.
14030/69 and 24844/77, etc.
These sensitizing dyes may be used alone or in combination. Combinations of
sensitizing dyes is often employed particularly for the purpose of
supersensitization. Typical examples thereof are described in U.S. Pat.
Nos. 2,688,545, 2,977,229, 3,397,060, 3,522,052, 3,527,641, 3,617,293,
3,628,964, 3,666,480, 3,672,898, 3,679,428, 3,703,377, 3,769,301,
3,814,609, 3,836,862, 4,026,707, British Pat. Nos. 1,344,281 and
1,507,803, Japanese Patent Publication Nos. 4936/68 and 12375/78, and
Japanese Patent Application (OPI) Nos. 110618/77 and 109925/77.
A dye which itself does not have a spectrally sensitizing effect or a
substance which substantially does not absorb visible light and which
shows a supersensitization effect may be incorporated together with the
sensitizing dye into the emulsion. For example, aminostilbene compounds
substituted with a nitrogen-containing hetero ring group (for example,
those described in U.S. Pat. Nos. 2,933,390 and 3,635,721), aromatic
organic acid-formaldehyde condensates (for example, those described in
U.S. Pat. No. 3,743,510), cadmium salts azaindene compounds, etc. may be
incorporated. Combinations described in U.S. Pat. Nos. 3,615,613,
3,615,641, 3,617,295, 3,635,721 are particularly useful.
Conventional processes may be applied to the light-sensitive material of
the present invention for photographic processing and known processing
solutions may be employed for the processing solution of the present
invention. The processing temperature is usually selected between
18.degree. and 50.degree. C. However, temperatures lower than 18.degree.
C. or higher than 50.degree. C. may be employed. Either a silver
image-forming development processing (black-and-white photographic
processing) or a color photographic processing composed of a dye
image-forming development processing may be applied depending upon the
end-use.
A color developing solution generally comprises an alkaline aqueous
solution containing a color-developing agent. As the color-developing
agent, known primary aromatic amine developing agents such as
phenylenediamines (e.g., 4-amino-N,N-diethylaniline,
3-methyl-4-amino-N,N-diethylaniline,
4-amino-N-ethyl-N-.beta.-hydroxyethylaniline,
3-methyl-4-amino-N-ethyl-N-.beta.-hydroxyethylaniline,
3-methyl-4-amino-N-ethyl-N-.beta.-methanesulfoamidoethylaniline,
4-amino-3-methyl-N-ethyl-N-.beta.-methoxyethylaniline, etc.) can be used.
In addition, those described in L.F.A. Mason; Photographic Processing
Chemistry (Focal Press, 1966), pp. 226-229, U.S. Pat. Nos. 2,193,015,
2,592,364, Japanese Patent Application (OPI) No. 64933/73, etc. may also
be used.
The color developing solution can further contain pH buffers such as alkali
metal sulfites, carbonates, borates, and phosphates, and development
inhibitors or anitfoggants such as bromides, iodides, and organic
antifoggants. If necessary, water softeners, preservatives such as
hydroxylamine, organic solvents such as benzyl alcohol or diethylene
glycol, development accelerators such as polyethylene glycol, quaternary
ammonium salts or amines, dye-forming couplers, competitive couplers,
fogging agents such as sodium borohydride, auxiliary developing agents
such as 1-phenyl-3-pyrazolidone, viscosity-imparting agents,
polycarboxylic acid series chelating agents described in U.S. Pat. No.
4,083,723, antioxidation agents described in West German Patent
Application (OLS) No. 2,622,950, and the like may be contained in the
developing solution.
After color development, the photographic emulsion layer is usually
bleached. Bleaching processing may be conducted simultaneously with, or
separately from, a fixing processing. As a bleaching agent, for example,
compounds of polyvalent metals such as iron (III), cobalt (III), chromium
(VI), copper (II), etc., peracids, quinones, nitroso compounds, etc. are
used. For example, ferricyanides, dichromates, organic complex salts of
iron (III) or cobalt (III), complex salts of aminopolycarboxylic acids
(e.g., ethylenediaminetetraacetic acid, nitrilotriacetic acid,
1,3-diamino-2-propanoltetraacetic acid, etc.) or organic acids (e.g.,
citric acid, tartaric acid, malic acid, etc.), persulfates, permanganates,
nitrosophenol, etc. can be used. Of these, potassium ferricyanide, iron
(III) sodium ethylenediaminetetraacetate, and iron (III) ammonium
ethylenediaminetetraacetate are particularly useful. Iron (III)
ethylenediaminetetraacetate complex salts are useful in both an
independent bleaching solution and a mono-bath bleach-fixing solution.
The bleaching or bleach-fixing solution may contain various additives
including bleaching-accelerating agents described in U.S. Pat. Nos.
3,042,520 and 3,241,966, Japanese Patent Publication Nos. 8506/70 and
8836/70, and thiol compounds described in Japanese Patent Application
(OPI) No. 65732/78.
The present invention will now be described in more detail by the following
non-limiting examples of preferred embodiments of the present invention.
EXAMPLE 1
A multi-layered color light-sensitive material sample comprising a
polyethylene terephthalate film support having thereon the following
layers of the following formulations was prepared.
1st layer: antihalation layer
A gelatin layer containing black colloidal silver.
2nd layer: interlayer
A gelatin layer containing an emulsion dispersion of
2,5-di-t-octylhydroquinone.
3rd layer: first red-sensitive emulsion layer
Silver iodobromide emulsion (AgI: 5 mol%) . . . coated in a silver amount
of 1.6 g/m.sup.2)
Sensitizing dye I . . . 6.times.10.sup.-5 mol/mol Ag
Sensitizing dye II . . . 1.5.times.10.sup.-5 mol/mol Ag
Coupler EX-1 . . . 0.04 mol/mol Ag
Coupler EX-5 . . . 0.003 mol/mol Ag
Coupler EX-6 . . . 0.0006 mol/mol Ag
4th layer: second red-sensitive emulsion layer
Silver iodobromide emulsion (AgI: 7 mol%) . . . coated in a silver amount
of 1.4 g/m.sup.2
Sensitizing dye I . . . 3.times.10.sup.-5 mol/mol Ag
Sensitizing dye II . . . 1.2.times.10.sup.-5 mol/mol Ag
Coupler EX-2 . . . 0.02 mol/mol Ag
Coupler EX-5 . . . 0.0016 mol/mol Ag
5th layer: interlayer
the same as the second layer
6th layer: first green-sensitive emulsion layer
Silver iodobromide emulsion (AgI: 4 mol%) . . . coated in a silver amount
of 1.2 g/m.sup.2
Sensitizing dye III . . . 3.times.10.sup.-5 mol/mol Ag
Sensitizing dye IV . . . 1.times.10.sup.-5 mol/mol Ag
Coupler EX-4 . . . 0.05 mol/mol Ag
Coupler EX-8 . . . 0.008 mol/mol Ag
Coupler Ex-6 . . . 0.0015 mol/mol Ag
7th layer: second green-sensitive emulsion layer
Silver iodobromide emulsion (AgI: 8 mol%) . . . coated in a silver amount
of 1.3 g/m.sup.2
Sensitizing dye III . . . 2.5.times.10.sup.-5 mol/mol Ag
Sensitizing dye IV . . . 0.8.times.10.sup.-5 mol/mol Ag
Coupler EX-10 . . . 0.017 mol/mol Ag
Coupler EX-3 . . . 0.003 mol/mol Ag
8th layer: yellow filter layer
A gelatin layer containing in a gelatin aqueous solution yellow colloidal
silver and an emulsion dispersion of 2,5-di-t-octylhydroquinone.
9th layer: first blue-sensitive emulsion layer
Silver iodobromide emulsion (AgI: 6 mol%) . . . coated in a silver amount
of 0.7 g/m.sup.2
Coupler EX-9 . . . 0.25 mol/mol Ag
Coupler EX-6 . . . 0.015 mol/mol Ag
10th layer: second blue-sensitive emulsion layer
Silver iodobromide emulsion (AgI: 6 mol%) . . . coated in a silver amount
of 0.6 g/m.sup.2
Coupler EX-9 . . . 0.06 mol/mol Ag
11th layer: first protective layer
Silver iodobromide (AgI: 1 mol%; mean grain size: 0.07.mu.) . . . coated in
a silver amount of 0.05 g/m.sup.2
Gelatin layer containing an emulsion dispersion of an ultraviolet
ray-absorbing agent, UV-1.
12th layer: second protective layer
A gelatin layer containing trimethylmethanoacrylate particles (diameter:
about 1.5.mu.) was coated.
A gelatin hardener, H-1, and a surfactant were added to each of the
above-described layers in addition to the above-described formulations.
The thus prepared sample was referred to as sample 101.
Compounds used for preparing sample 101:
Sensitizing dye I:
anhydro-5,5'-dichloro-3,3'-di-(.gamma.-sulfopropyl)-9-ethyl-thiacarbocyani
ne hydroxide pyridinium salt
Sensitizing dye II;
anhydro-9-ethyl-3,3'-di-(.gamma.-sulfopropyl)-4,5,4',5'-dibenzothiacarbocy
anine hydroxide triethylamine salt
Sensitizing dye III:
anhydro-9-ethyl-5,5'-dichloro-3,3'-di(.gamma.-sulfopropyl)oxacarbocyanine
sodium salt
Sensitizing dye IV:
anhydro-5,6,5',6'-tetrachloro-1,1'-diethyl-3,3'-di-{.beta.-[.beta.(.gamma.
-sulfopropyl)ethoxy]ethylimidazolocarbocyanine hydroxide sodium salt
##STR1##
A primitive silver iodobromide emulsion (AgI: 2 mol%) of 0.25 .mu.m in
average grain size was prepared according to a double jet process in which
pAg was controlled upon addition. Sample 102 in which a light-insensitive
layer (NS) containing 0.75 g/m.sup.2 of the above-described emulsion was
provided between the 8th layer and the 9th layer of sample 101, and sample
103 in which the NS layer was provided between the 9th layer and the 10th
layer were prepared.
Sample 104 was prepared in the same manner as with sample 101 except for
providing a 9'th layer of the following formulation in place of the 9th
layer and the 10th layer.
Sample 105 in which the foregoing light-insensitive emulsion was provided
between the 8th layer and the 9'th layer of sample 104 was prepared.
9'th layer: blue-sensitive emulsion layer
Silver iodobromide emulsion (AgI: 6 mol%; average grain size: 0.7.mu.) . .
. coated in a silver amount of 2.6 g/m.sup.2
The emulsion used herein had a grain size distribution controlled so that
it possesses the same sensitivity gradation as that of the blue-sensitive
emulsion layers of sample 101.
Sample 106 was prepared in the same manner as with sample 103 except for
providing a light-insensitive layer (NS') between the 9th layer and the
10th layer of sample 103 in place of the light-insensitive layer of sample
103.
NS' layer:
Primitive silver iodobromide emulsion used in NS layer . . . 0.75 g/m.sup.2
Coupler EX-9 . . . 2.0.times.10.sup.-4 mol/m.sup.2
Each of the thus prepared samples 101 to 106 was exposed through a filter
having stepwise changing densities, then subjected to the following
development processing. The following processing was conducted at
38.degree. C.
______________________________________
1. Color development 3 min. & 15 sec.
2. Bleaching 6 min. & 30 sec.
3. Washing with water
3 min. & 15 sec.
4. Fixing 6 min. & 30 sec.
5. Washing with water
3 min. & 15 sec.
6. Stabilizing 3 min. & 15 sec.
______________________________________
Formulations of the processing solutions used in the above-described steps
are as follows.
______________________________________
Color developing solution
Sodium nitrilotriacetate 1.0 g
Sodium sulfite 4.0 g
Sodium carbonate 30.0 g
Potassium bromide 1.4 g
Hydroxylamine sulfate 2.4 g
4-(N--Ethyl-N--.beta.-hydroxyethylamino)-
4.5 g
2-methylaniline sulfate
Water to make 1 liter
Bleaching solution
Ammonium bromide 160.0 g
Aqueous ammonia (28%) 25.0 ml
Sodium iron ethylenediaminetetraacetate
130.0 g
Glacial acetic acid 14.0 ml
Water to make 1 liter
Fixing solution
Sodium tetrapolyphosphate
2.0 g
Sodium sulfite 4.0 g
Ammonium thiosulfate (70%)
175.0 ml
Sodium bisulfite 4.6 g
Water to make 1 liter
Fixing solution
Formalin 8.0 ml
Water to make 1 liter
______________________________________
Sensitivities and graininesses of the yellow images of the samples thus
formed were measured. Graininess was measured according to conventional
RMS method. The aperture for the measurement was 48.mu..
______________________________________
Sensitivity
Graininess (RMS Values
Sample No. (Relative)
At A Density of 2.0)
______________________________________
101 (*) 100 0.030
102 (*) 150 0.044
103 (**) 180 0.022
104 (*) 100 0.045
105 (*) 150 0.056
106 (**) 130 0.038
______________________________________
(*) comparative example
(**) present invention
As is clear from the above table, sample 103 in which a light-insensitive
emulsion layer was provided between a more sensitive emulsion layer and a
less sensitive emulsion layer showed rather improved graininess despite
the fact that the sensitivity was almost doubled. In comparison with
sample 102 in which a light-insensitive layer was provided under a less
sensitive emulsion layer, sample 103 provides excellent results in that
its sensitivity and graininess are simultaneously improved. In addition,
in comparison with the sample which had one blue-sensitive layer, the
layer structure of the present invention proved to show specific effects
with respect to sensitivity and graininess.
Samples having couplers in the light-insensitive layer showed less
sensitivity and less graininess than those having no couplers. Therefore,
it is seen that the use of a coupler-free, light-insensitive emulsion
layer is advantageous because it provides great effects of the present
invention.
EXAMPLE 2
Primitive silver bromide emulsions of 0.05, 0.14, 0.23, 0.45, 0.72, and
0.97 .mu.m in average grain size were prepared as follows.
A silver nitrate aqueous solution and a potassium bromide aqueous solution
were simultaneously added to a gelatin aqueous solution kept at a definite
temperature, during which the pAg in the reactor tank was kept at 7.9, to
prepare a cubic silver bromide grains emulsion. By changing the adding
time of the silver nitrate aqueous solution and the potassium bromide
aqueous solution and changing the temperature of the reaction tank, six
emulsions having grain sizes of 0.05 .mu.m, 0.14 .mu.m, 0.24 .mu.m, 0.45
.mu.m, 0.72 .mu.m, and 0.97 .mu.m, respectively, were prepared.
Samples 202 to 207 were prepared in the same manner as with sample 101
except for providing a light-insensitive emulsion layer containing 0.26
g/m.sup.2 of each of these emulsions between the 9th layer and the 10th
layer of Example 1.
These samples 202 to 207 and sample 101 were exposed and developed in the
same manner as in Example 1. Sensitivities and graininesses of formed
yellow images of the samples were measured in the same manner as in
Example 1.
Results thus obtained are tabulated in Table 2.
TABLE 2
______________________________________
Grain Size
of Light-
insensitive Relative
Sample No.
Emulsion Layer
Sensitivity
Graininess
______________________________________
101 (control)
-- 100 0.030
202 (*) 0.05 115 0.030
203 (*) 0.14 125 0.028
204 (*) 0.23 130 0.026
205 (*) 0.45 118 0.025
206 (**) 0.72 100 0.025
207 (**) 0.97 95 0.025
______________________________________
(*) present invention
(**) comparative example
As is clear from Table 2, samples 202, 203, 204, and 205 in accordance with
the present invention having grain sizes of 0.05, 0.14, 0.23, and 0.45
.mu.m, respectively, showed increased sensitivities and tended to show
improved graininesses. However, samples 206 and 207 did not show an
increase in sensitivity. Thus, application of the present invention proved
to be effective.
EXAMPLE 3
Sample 301 was prepared in the same manner as with sample 101 in Example 1
except for providing a first blue-sensitive emulsion layer having slower
sensitivity (which refers to a 9S layer) and a first blue-sensitive
emulsion layer having faster sensitivity (which refers to a 9F layer)
according to the following formulations in place of a first blue-sensitive
emulsion layer (i.e., a 9th layer).
9S layer: first blue-sensitive emulsion layer having slower sensitivity
Silver iodobromide emulsion (Ag I: 4 mol%) . . . coated in a silver amount
of 0.5 g/m.sup.2
Coupler EX-9 . . . 0.30 mol/mol Ag
Coupler EX-6 . . . 0.025 mol/mol Ag
9F layer: first blue-sensitive emulsion layer having faster sensitivity
Silver iodobromide emulsion (AgI: 6 mol%) . . . coated in a silver amount
of 0.25 g/m.sup.2
Coupler EX-9 . . . 0.17 mol/mol Ag
Coupler EX-6 . . . 0.010 mol/mol Ag
A primitive silver iodobromide emulsion of 0.15 .mu.m in average grain size
was prepared according to the following process. A silver nitrate aqueous
solution and an aqueous solution containing a mixture of 98 mol% of
potassium bromide and 2 mol% of potassium iodide based on mol of silver
halides were simultaneously added to a gelatin aqueous solution in reactor
tank, while keeping the pAg of mixture in reactor tank at 7.9 and the
temperature of mixture at 50.degree. C. consequently to obtain emulsion
containing cubic silver iodobromide particles. The average grain size was
0.15 .mu.m. Sample 302 in which a light-sensitive layer containing 0.30
g/m.sup.2 of the above-described emulsion was provided between the 8th
layer and the 9S layer, sample 303 in which the light-insensitive layer
was provided between the 9S layer and the 9F layer and sample 304 in which
the light-insensitive layer was provided between the 9F layer and the 10th
layer were prepared.
These samples 301 to 304 were exposed and developed in the same manner as
in Example 1. Sensitivities and graininess of formed yellow images of the
samples were measured in the same manner as in Example 1.
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