Silver halide photographic material and image forming method using the same

A silver halide photographic material and an image forming method using such material are described, said material comprising a surface latent image forming silver halide emulsion layer unit on a support, and containing a hydrazine compound in at least one of said emulsion layer unit and other constituent layers, said emulsion layer unit being composed of at least two layers, with the silver halide emulsion present in a fine-grained low-sensitivity emulsion layer having a minimum average grain size being not more than 80% of the average grain size of a coarse-grained high-sensitivity silver halide emulsion having the maximum average grain size, and said silver halide photographic material attains a contrast of 10 or more in terms of gamma value when a developer containing at least 0.15 mol/liter of sulfite ions and having a pH of from 9.5 to 12.3 is used.

FIELD OF THE INVENTION 
The present invention relates to a silver halide photographic material that 
is suitable for use in the field of photomechanical processes and which is 
capable of rapid formation of a super-high contrast image with a highly 
stable processing solution. 
BACKGROUND OF THE INVENTION 
It is known that a very high-contrast photographic image can be formed 
using a certain kind of silver halide, and various methods for forming 
such a photographic image are employed in the field of photo mechanical 
processes. 
According to one method, a lith-type silver halide light-sensitive material 
comprising silver chlorobromide (at least 50 mol % of which is silver 
chloride) is processed with a hydroquinone developer having a very low 
effective concentration of sulfite ions (usually not more than 0.1 
mol/liter) so as to obtain a halftone image or line original having high 
contrast and optical density wherein image areas are clearly distinguished 
from nonimage areas. However, the development achieved by this method is 
extremely liable to aerial oxidation because of the low sulfite 
concentration in the developer, and various efforts and approaches have 
been necessitated to stabilize the activity of the developer. 
Under the situation described above, it has been desired to devise an 
image-forming system that eliminates the instability in image formation by 
the aforementioned developing method (lith development system) and which 
provides super high contrast photographic characteristics by development 
with a processing solution having improved stability during storage. In 
response to this need, systems capable of forming super high contrast 
negative images (.gamma.&gt;10) have been described in U.S. Pat. Nos. 
4,166,742, 4,168,977, 4,221,857, 4,224,401, 4,243,739, 4,272,606, and 
4,311,781; according to the described methods, surface latent-image type 
silver halide photographic materials to which specified acylhydrazine 
compounds have been added are processed at a pH between 11.0 and 12.3 with 
developers that contain at least 0.15 mol/liter of a preservative 
sulfurous acid and which exhibit good stability during storage. The new 
image-forming systems permit the use of silver iodobromide or silver 
chloroiodobromide, which is a definite advantage over the previously 
described methods for forming super high contrast images which can be 
implemented solely by the use of silver chlorobromide with high silver 
chloride content. 
With the commonly employed silver halide photographic materials, the 
optical density of an image obtainable per unit amount of developed silver 
increases in inverse proportion to the size of silver halide grains but, 
on the other hand, the sensitivity of a silver halide generally increases 
in the size of silver halide grains. Therefore, in order to obtain a 
light-sensitive material that provides both high sensitivity and high 
optical density, it is necessary that a silver halide emulsion having a 
large grain size be incorporated in an increased amount per unit area. 
However, light-sensitive material containing a larger amount of silver 
halide emulsion is not adaptive to rapid processing, since it takes a 
prolonged time to fix, wash, and dry the developed material. In addition, 
silver is a precious metal whose world production and reserves are 
limited, so that it is economically advisable to produce light-sensitive 
materials with minimum use of silver. 
Under these circumstances, studies have been conducted for many years in 
order to realize the production of silver halide light-sensitive materials 
having high image density and sensitivity while using silver in a reduced 
amount. 
The new image-forming systems described above which are capable of forming 
extremely high contrast images in high speed have a serious disadvantage 
in that they sometimes cause the formation of "black pepper" due to 
infectious development, and this presents a problem in photomechanical 
processes. 
"Black pepper" refers to the formation of tiny black spots of developed 
silver that occur in the areas which would otherwise be unexposed nonimage 
areas. Black pepper tends to occur more frequently if the pH of the 
processing solution increases, for reasons such as fatigue with time. 
While extensive efforts have been made in order to prevent the occurrence 
of black pepper, success in reducing the formation of black pepper is 
often accompanied by a decrease in sensitivity or image contrast. 
Therefore, it has been desired to devise a system that maintains 
high-sensitivity and super high contrast photographic characteristics but 
yet is capable of satisfactory prevention of black pepper. 
SUMMARY OF THE INVENTION 
One object, therefore, of the present invention is to provide a silver 
halide photographic material that undergoes minimal formation of black 
pepper but yet is capable of achieving a high-speed and high-contrast 
image with an increased optical density. 
Another object of the present invention is to provide an image-forming 
method using said silver halide photographic material. 
The first object of the present invention can be attained by a silver 
halide photographic material comprising a surface latent-image type silver 
halide emulsion layer unit on a support, and containing a hydrazine 
compound in at least one of said emulsion layer unit and other constituent 
layers, said emulsion layer unit being composed of at least two layers, 
with the silver halide emulsion present in a fine-grained low-sensitivity 
emulsion layer having a minimum average grain size being not more than 80% 
of the average grain size of a coarse-grained high-sensitivity silver 
halide emulsion having the maximum average grain size, and said silver 
halide photographic material attains a contrast of 10 or more in terms of 
gamma value when a developer containing at least 0.15 mol/liter of sulfite 
ions and having a pH of from 9.5 to 12.3 is used. 
The second object of the present invention can be attained by an 
image-forming method wherein the aforementioned silver halide photographic 
material is subjected to an imagewise exposure and subsequently developed 
with a developer that contains at least 0.15 mol/liter of sulfite ions and 
which has a pH of from 9.5 to 12.3, so as to provide a gamma value of 10 
or more.

In both of FIGS. 1 and 2, the abscissa shows the logarithm of the exposure 
amount (log E), and the ordinate shows the optical density after 
processing of the development (Density). 
DETAILED DESCRIPTION OF THE INVENTION 
The terminology "average grain size" as used herein refers to the average 
size of all of the silver halide grains present in a particular silver 
halide emulsion layer. Furthermore, the average grain size refers to the 
diameter of the grains when the silver halide grains are spherical or 
similar to spherical grains, or indicates a calculated diameter value 
based on projected areas of the grains in the case of nonspherical type 
grains (e.g., such as cubic grains). 
The processes for determining the average grain size are described in 
detail in C. E. Mees & T. H. James, The Theory of the Photographic 
Process, 3rd Ed., pp. 36-43, MacMillan (1966). 
If a hydrazine derivative is incorporated in emulsion layers, it may be 
present in at least one of such emulsion layers. Alternatively, the 
hydrazine derivative may be contained in more than one emulsion layer or 
even in all of the emulsion layers used. 
The high sensitivity and high optical density (D.sub.max) desired in the 
present invention are attainable only with a light-sensitive material that 
provides a super high contrast characteristic having a gamma value of 10 
or more, and which contains a hydrazine derivative. 
In the present invention, at least two surface latent-image type silver 
halide emulsions having different average grain sizes are used, and in 
particular, two surface latent-image type silver halide emulsions are 
preferably used. The following description assumes the use of two such 
silver halide emulsions. The emulsion having the large average grain size 
is more sensitive than the other emulsion having the smaller average size 
but has the disadvantage of a smaller optical density D per unit amount of 
silver M (D/M =covering power). When the two emulsions having different 
grain sizes are applied to form a double-layered emulsion coat, the 
sensitivity attained is much lower than that of the coarse-grained 
emulsion and approaches that of the fine-grained emulsion as shown in FIG. 
2 if the gamma value is smaller than 10 in the absence of any hydrazine 
derivative. On the other hand, as shown in FIG. 1, the system of the 
present invention which incorporates a hydrazine derivative displays the 
advantage of an increased D.sub.max while substantially retaining the 
sensitivity of the coarse grains Characteristic curves 1 to 3 in FIG. 1 
and curves 4 to 6 in FIG. 2 assume the case of using the same amount of 
silver coated, provided that in a double-layered structure, the coarse- 
and fine-grained emulsions are used in weight ratios of 25 wt % and 75 wt 
% , respectively, and the amount of silver coated is the same as in the 
case of using either the coarse-grained or fine-grained emulsion alone. 
The above-described advantage of the present invention results from 
infectious development that proceeds with the hydrazine derivative being 
used as an active species. The hydrazine derivative active species that is 
generated as result of development of the exposed coarse grain is thought 
to render the surrounding unexposed grains (fine grains) developable in an 
image-related manner so as to attain a high contrast characteristic. 
The advantages attained by the system of the present invention are 
remarkable in that the formation of black pepper is reduced, and yet an 
increased D.sub.max is obtained with a negligible decrease in sensitivity. 
Such advantages are absent from processing with a lith developer (i.e., 
the prior art system of providing a super high contrast characteristic by 
infectious development using an extremely low level of sulfite ions but 
without using any hydrazine derivative) and have been entirely unexpected 
from the prior art technology. In the system of the present invention, 
infectious development by the active species provided by the hydrazine 
derivative is important and a gamma value of 10 or more is obtained if 
such infectious development progresses actively. Therefore, particularly 
good results are attained by the present invention under conditions that 
provide a gamma value of 10 or more. 
The light-sensitive material of the present invention uses two or three or 
more emulsion layers (preferably two emulsion layers) and is hereinafter 
described with respect to the case where two emulsion layers are used. 
There is no particular limitation on the silver halide grains used in a 
two-layered emulsion coat consisting of an 0-layer (the layer remote from 
the support) and a U-layer (the one closer to the support) but the average 
grain size is preferably large, and, from a sensitivity viewpoint, it is 
advantageous that the higher-sensitivity emulsion is present in the 
0-layer. The fine-grained emulsion may be unsensitized chemically but more 
preferably it is chemically sensitized. Methods that can be used to 
chemically sensitize the fine-grained emulsion are described later in this 
speicification and include such known techniques as sulfur sensitization, 
reduction sensitization and gold sensitization. The coarse-grained 
emulsion may or may not be chemically sensitized. The difference in 
sensitivity between the coarse-grained high-sensitivity emulsion and the 
fine-grained low-sensitivity emulsion that are preferably used in the 
present invention is not limited to any particular value, but preferably 
the difference is from 0.1 to 1.0, and more preferably from 0.2 to 0.7, in 
terms of .DELTA. log E. The silver halide emulsions have an average grain 
size which preferably ranges from 0.02 to 1.0 .mu. m, and more preferably 
from 0.1 to 0.5 .mu. m. It is preferable that the average grain sizes of 
the coarse and fine grains are included within these ranges. 
The fine-grained emulsion having a minimum average grain size is preferably 
applied such that the amount of silver coated is from 40 to 90 wt % of the 
total silver content, with from 50 to 80 wt % being more preferable, of 
the emulsion layer unit. 
The halide composition of the silver halide emusions used in the present 
invention is in no way limited and they may composed of any silver halide 
such as silver chloride, silver bromide, silver chlorobromide, silver 
iodobromide, silver iodochloride, or silver iodochlorobromide. If two 
emulsions are used, their halide compositions may be the same or 
different. 
The silver halide emusions used in the present invention may be prepared by 
any of the methods known in the art of silver halide photographic 
materials, such as those described in P. Glafkides, Chimie et Physique 
Photographique, Paul Montel Co., Paris (1967); G. F. Duffin, Photographic 
Emulsion Chemistry, The Focal Press, London (1966); and V. L. Zelikman et 
al., Making and Coating Photographic Emulsions, The Focal Press, London 
(1964). Furthermore, the silver halide emulsions and the process for 
preparing the same are described in detail in Research Disclosure, Vol. 
176, No. 17643, pages 22-23 (December 1978). The water-soluble silver salt 
(an aqueous solution of silver nitrate) may be reacted with a 
water-soluble halide salt by either the single-jet method, the double-jet 
method or a combination thereof. One application of the double-jet method 
is what is called the "controlled double jet method" wherein the pAg is 
held constant in a liquid phase where silver halide is being formed. 
Silver halide grains may also be formed by using a "silver halide solvent" 
such as ammonia, thioether, or tetra-substituted thiourea. 
Grain formation by the controlled double-jet method using a silver halide 
solvent allows for easy preparation of a silver halide emulsion having a 
regular crystal shape and a narrow grain-size distribution, and hence is 
an effective means for obtaining an emulsion that is suitable for use in 
the present invention. 
The silver halide grains in the photographic emulsion may have a regular 
crystal shape such as cubic or octahedral, or they may have an irregular 
crystal shape, such as spherical or plate-like. 
The grain size distribution is preferably narrow and it is preferable that 
at least 90%, and more preferably at least 95%, of the total number of 
silver halide grains lies within the range of grain sizes which are 
.+-.40% of the average grain size (such an emulsion is generally called a 
monodisperse emulsion). 
The silver halide grains may be homogeneous throughout the interior 
thereof, or, alternatively, they may be composed of a core and shell which 
have different phases. 
During the formation or physical ripening of the silver halide grains to be 
incorporated in the silver halide emulsion used in the present invention, 
cadmium salts, zinc salts, lead salts, thallium salts, iridium salts or 
complexes thereof, rhodium salts or complexes thereof may also be present. 
The silver halide emulsion used in the present invention may or may not be 
chemically sensitized. Methods for chemical sensitization which can be 
used include known techniques such as sulfur sensitization, reduction 
sensitization and gold sensitization, which may be employed either 
independently or in combination. 
Gold sensitization is a typical method of noble metal sensitization and is 
implemented with a gold compound which is typically a gold complex salt. 
Complex salts of other noble metals such as platinum, palladium and 
iridium may also be used. Specific examples of such complex salts are 
described in U.S. Pat. No. 2,448,060 and British Patent Ser. No. 618,061. 
Sulfur sensitizing agents which may be used include not only the sulfur 
compounds present in gelatin but also a variety of other sulfur compounds 
such as thiosulfates, thioureas, thiazoles and rhodanines. Specific 
examples of the sulfur sensitizing agents are shown in U.S. Pat. Nos. 
1,574,944, 2,278,947, 2,410,689, 2,728,668, 3,501,313, and 3,656,955. 
Usable reduction sensitizers include stannous salts, amines, formamidine 
sulfinic acid, and silane compounds, and specific examples are described 
in U.S. Pat. Nos. 2,487,850, 2,518,698, 2,983,609, 2,983,610, and 
2,694,637. 
The silver halide emulsions used in the present invention may be optically 
sensitized with a view to attaining increased sensitivity and providing a 
light sensitivity in a desired wavelength range. Sensitizing dyes such as 
cyanine and merocyanine dyes may be used either independently or in 
combination to achieve spectral sensitization or supersensitization. 
Details of such sensitization techniques are described in U.S. Pat. No. 
2,688,545, 2,912,329, 3,397,060, 3,615,635, and 3,628,964; Japanese Patent 
Publication Nos. 4936/68 and 14030/69; and Japanese Patent Application 
(OPI) No. 52050/80 (the term "OPI" as used herein means a "published 
unexamined Japanese Patent application"). 
Preferable examples of hydrazine derivatives which may be used in the 
present invention are the arylhydrazides of the type described in U.S. 
Pat. No. 4,478,928 wherein the sulfinic acid residue is bonded to the 
hydrazo portion, and compounds represented by formula (I) 
EQU R.sub.1 --NHNH--G--R.sub.2 (I) 
wherein R.sub.1 represents an aliphatic group or an aromatic group; R.sub.2 
represents a hydrogen atom, a substituted or unsubstituted alkyl group, a 
substituted or unsubstituted aryl group, a substituted or unsubstituted 
alkoxy group, or a substituted or unsubstituted aryloxy group; and G 
represents a carbonyl group, a sulfonyl group, a sulfoxy group, a 
phosphoryl group, or an N-substituted or unsubstituted iminomethylene 
group. 
The aliphatic group denoted by R.sub.1 in formula (I) preferably has 1 to 
30 carbon atoms, with a straight-chained, branched or cyclic alkyl group 
having from 1 to 20 carbon atoms being particularly preferable. The 
branched alkyl group may be cyclized in such a manner that a saturated 
hetero ring containing one or more hetero atoms may be formed. The alkyl 
group may have a substituent such as an aryl, alkoxy, sulfoxy, sufonamido 
or carbonamido group. 
The aromatic group denoted by R.sub.1 is a monocyclic or bicyclic aryl 
group or an unsaturated hetero cyclic group, the latter being optionally 
condensed with a mono- or bicyclic aryl group to form a heteroaryl group. 
Illustrative aromatic groups include a benzene ring, a naphthalene ring, a 
pyridine ring, a pyrimidine ring, an imidazole ring, a pyrazole ring, a 
quinoline ring, an isoquinoline ring, a benzimidazole ring, a thiazole 
ring, and a benzothiazole ring, and those which contain a benzene ring are 
particularly preferable. 
As aryl group is particularly preferable as R.sub.1. The aryl group or 
unsaturated hetero cyclic group as R.sub.1 may have a substituent and 
typical substituents include a straight-chained, branched, or cyclic alkyl 
group (preferably having from 1 to 20 carbon atoms), an aralkyl group 
(which is preferably a mono- or bicyclic aralkyl group wherein the alkyl 
moiety has 1 to 3 carbon atoms), an alkoxy group (preferably having from 1 
to 20 carbon atoms), a substituted amino group (preferably one which is 
substituted by an alkyl group with from 1 to 20 carbon atoms), an 
acylamino group (preferably having from 2 to 30 carbon atoms), a 
sulfonamido group (preferably having from 1 to 30 carbon atoms), and a 
ureido group (preferably having from 1 to 30 carbon atoms). 
The alkyl group denoted by R.sub.2 is preferably one having from 1 to 4 
carbon atoms and may have a substituent such as a halogen atom, a cyano 
group, a carboxy group, a sulfo group, an alkoxy group or a phenyl group. 
The optionally substituted aryl group denoted by R.sub.2 is a mono- or 
bicyclic aryl group which may contain a benzene ring. This aryl group may 
be substituted by, for example, a halogen atom, an alkyl group, a cyano 
group, a carboxyl group, or a sulfo group. 
The optionally substituted alkoxy group denoted by R.sub.2 is one having 
from 1 to 8 carbon atoms and may be substituted, for example, by a halogen 
atom or an aryl group. 
The optionally substituted aryloxy group denoted by R.sub.2 is preferably 
monocyclic and may have a substituent such as a halogen atom. 
Preferable examples of the group denoted by R.sub.2 are listed below: when 
G is a carbonyl group, they are hydrogen atom, a methyl group, a methoxy 
group, an ethoxy group, a substituted or unsubstituted phenyl group, with 
the hydrogen atom being particularly preferable; when G is a sulfonyl 
group, preferable examples of R.sub.2 are a methyl group, an ethyl group, 
a phenyl group, or a 4-methylphenyl group, with the methyl group being 
particularly preferable; when G is a phosphoryl group, preferable examples 
of R.sub.2 are a methoxy group, an ethoxy group, a butoxy group, a phenoxy 
group, and a phenyl group, with the phenoxy group being particularly 
preferable; when G is a sulfoxy group, preferable examples of R.sub.2 are 
a cyanobenzyl group and a methylthiobenzyl group; and when G is an 
N-substituted or unsubstituted iminomethylene group, preferable examples 
of R.sub.2 are a methyl group, an ethyl group, and a substituted or 
unsubstituted phenyl group. 
A ballast group which is commonly employed in couplers and of the immobile 
photographic additives may be incorporated in R.sub.1 or R.sub.2. The 
ballast group is one having at least 8 carbon atoms which is comparatively 
inert to photographic properties; a suitable ballast group may be selected 
from among alkyl, alkoxyl, phenyl, alkylphenyl, phenoxyl and alkylphenoxy 
groups. 
A group which provides enhanced adsorpotion to the surface of silver halide 
grains may also be incorporated in R.sub.1 or R.sub.2. Illustrative 
adsorptive groups include a thiourea group, a heterocyclic thioamido 
group, a mercapto heterocyclic group and a triazole group, and such are 
described in U.S. Pat. No. 4,385,108. 
A carbonyl group is most preferable as G in the formula (I). 
Specific examples of the compounds represented by formula (I) are listed 
below, but it should be noted that these examples of compound (I) do not 
limit the scope of the present invention. 
##STR1## 
The compounds represented by formula (I) are preferably incorporated in 
amounts of from 1.times.10.sup.-6 to 5.times.10.sup.-2 moles per mole of 
silver halide, with the range of from 1.times.10.sup.-5 to 
2.times.10.sup.-2 moles being particularly preferable. 
The compounds of formula (I) may be incorporated in a photographic material 
in the following manner: if they are water-soluble, aqueous solutions 
thereof are added to a solution of silver halide emulsion (e.g., 
coarse-grained emulsion, or fine-grained emulsion) or a hydrophilic 
colloid solution; if the compounds are water-insoluble, they are added in 
the form of a solution in a water-miscible organic solvent such as an 
alcohol (e.g., methanol or ethanol), an ester (e.g., ethyl acetate) or a 
ketone (e.g., acetone) to a solution of silver halide emulsion (e.g., 
course-grained emulsion, or fine-grained emulsion) or a hydrophilic 
colloid solution. 
If the compounds of formula (I) are to be added to a solution of silver 
halide emulsion, the addition may be conducted at any point of time during 
the time interval from the start of chemical ripening to the application 
of the coating solution. Addition after completion of the chemical 
ripening is preferable, and it is particularly preferable to add the 
compounds to a coating solution prepared for application of the emulsion. 
The photographic emulsion used in the present invention may contain various 
compounds for the purpose of preventing the occurrence of fogging during 
the manufacture, storage or photographic processing of the light-sensitive 
material or for stabilizing its photographic performance. Many compounds 
that are known in the art as anti-foggants or stabilizers may be used for 
these purposes and they include: azoles such as benzothiazolium salts, 
nitroindazoles, nitrobenzimidazoles, chlorobenzimidazoles, 
bromobenzimidazoles, mercaptothiazoles, mercaptobenzpyothiazoles, 
mercaptobenzimidazoles, mercaptothiadiazoles, amino-triazoles, 
benzotriazoles, nitrobenzotriazoles, and mercaptotetrazoles (e.g., 
1-phenyl-5-mercaptotetrazole); mercaptopyrimidines; mercaptotriazines; 
thioketo compounds such as oxadolinethione; azaindenes such as 
triazaindenes, tetrazaindenes (e.g., 4-hydroxy-substituted (1,3,3a,7) 
tetrazaindenes) and pentazaindenes; benzenethiosulfonic acid, 
benzenesulfinic acid and benzenesulfonic acid amide. 
Of these compounds, benzotriazoles (e.g., 5-methylbenzotriazole) and 
nitroindazoles (e.g., 5-nitroindazole) are particularly preferable. These 
compounds may be incorporated in a processing solution. 
The photographic material of the present invention may contain inorganic or 
organic hardening agents in photographic emulsion layers or other 
hydrophilic colloidal layers. Suitable hardening agents, which may be used 
either independently or in combination, include: chromium salts (e.g., 
chrome alum and chromium acetate), aldehydes (e.g., formaldehyde, glyoxal 
and glutaraldehyde), N-methylol compounds (e.g., dimethylolurea and 
methyloldimethylhydantoin), dioxane derivatives (e.g., 
2,3-dihydroxydioxane), active vinyl compounds (e.g., 
1,3,5-triacryloylhexahydro-s-triazine and 1,3-vinylsulfonyl-2-propanol), 
active halogen compounds (e.g., 2,4-dichloro-6-hydroxy-s-triazine), and 
mucohalogenic acids (e.g., mucochloric acid and mucophenoxychloric acid). 
The photographic emulsion layers and other hydrophilic colloidal layers in 
the light-sensitive material that is prepared in accordance with the 
present invention may contain various surface active agents for attaining 
various purposes such as, for example, assisting in coating operations, 
improving anti static properties, providing improved sliding properties, 
achieving emulsification or dispersion, preventing adhesion and providing 
improved photographic characteristics (e.g., accelerating the rate of 
development, increasing contrast, or providing sensitization). Suitable 
surface active agents are listed below: nonionic surfactants such as 
saponin (steroid type), alkylene oxide derivatives (e.g., polyethylene 
glycol, polyethylene glycol/polypropylene glycol condensation products, 
polyethylene glycol alkyl ethers, polyethylene glycol alkylaryl ethers, 
polyethylene glycol esters, polyethylene glycol sorbitan esters, 
polyalkylene glycol alkylamines or amides, and polyethylene oxide adducts 
of silicone), glycidol derivatives (e.g., alkenyl-succinic acid 
polyglycerides and alkylphend polyglycerides), aliphatic acid esters of 
polyhydric alcohols, and alkyl esters of saccharides; anionic surfactants 
containing acidic groups such as a carboxyl group, a sulfo group, a 
phospho group, a sulfate group, or a phosphate group, such as 
alkylcarboxylic acid salts, alkylsulfonic acid salts, alkylbenzenesulfonic 
acid salts, alkylnaphthalenesulfonic acid salts, alkylsulfuric acid 
esters, alkylphosphoric acid esters, N-acyl-N-alkyltaurines, sulfosuccinic 
acid esters, sulfoalkylpolyoxyethylene alkylphenyl ethers, and 
polyoxyethylene alkyl phosphoric acid esters; amphoteric surfactants such 
as amino acids, aminoalkylsulfonic acids, aminoalkylsulfate or phosphate 
esters, alkylbetaines, and amine oxides; and catinonic surfactants such as 
alkylamine salts, aliphatic or aromatic quaternary ammomium salts, 
heterocyclic quaternary ammonium salts (e.g., pyridinium and imidazolium 
salts), and aliphatic or heterocyclic phosphonium or sulfonium salts. 
Surface active agents which are preferably used in the present invention 
are the polyalkylene oxides described in U.S. Pat. No. 4,221,857 which 
have molecular weights of 600 or more. 
The photographic material of the present invention may also contain 
dispersions of water-insoluble or sparingly water-soluble synthetic 
polymers in photographic emulsion layers or other hydrophilic colloidal 
layers for the purpose of improving the dimensional stability thereof. 
Illustrative polymers are those of monomers such as alkyl (meth)acrylates, 
alkoxyalkyl (meth)acrylates. glycidyl (meth)acrylates, (meth)acrylamides, 
vinyl esters (e.g., vinyl acetate), acrylonitrile, olefins and styrene, 
which may be used either individually or in combination, or polymers of 
these monomers combined with other monomeric components such as acrylic 
acid, methacrylic acid, .alpha., .beta.-unsaturated dicarboxylic acids, 
hydroxyalkyl (meth)acrylates, sulfoalkyl (meth)acrylates, and 
styrenesulfonic acid. 
With a view to reducing black pepper, the pH of the emulsion coat may be 
reduced by using inorganic acids, organic acids, or acidic polymers as 
described in U.S. Patent Application Serial Nos. 845,298 (filed on March 
28, 1986) and 846,679 (filed on Apr. 1, 1986). 
Photographic processing of the silver halide photographic material of the 
present invention does not require the use of the conventional lith 
developer which has an extremely low level of the effective concentration 
of sulfite ions or the highly alkaline (pH about 13) developer shown in 
U.S. Pat. No. 2,419,975. A super high contrast negative image may be 
formed by processing the photographic material of the present invention 
with a developer of the type described below. 
The developing agent that can be incorporated in the developer suitable for 
use in the present invention is not limited to any particular compound, 
but in view of that good dot quality is liable to be obtained, the 
developer preferably contains a dihydroxybenzene, which may be combined 
with a 1-phenyl-3-pyrazolidone or p-aminophenol. 
Illustrative dihydroxybenzene compounds suitable for use as developing 
agents include hydroquinone, chlorohydroquinone, bromohydroquinone, 
isopropyl hydroquinone, methyl hydroquinone, 2,3-dichlorohydroquinone, 
2,5-dichlorohydroquinone, 2,3-dibromohydroquinone, and 2,5-dimethyl 
hydroquinone, with hydroquinoe being particularly preferable. 
Illustrative 1-phenyl-3-pyrazolidone and derivatives thereof which are 
suitable for use as developing agents include 1-phenyl-3-pyrazolidone, 
1-phenyl-4,4-dimethyl-3-pyrazolidone, 
1-phenyl-4-methyl-4-hydroxymethyl-3-pyrazolidone, 
1-phenyl-4,4-dihydroxy-methyl-3-pyrazolidone, 
1-phenyl-5-methyl-3-pyrazolidone, 
1-p-aminophenyl-4,4-dimethyl-3-pyrazolidone, and 1-p 
tolyl-4,4-dimethyl-3-pyrazolidone. 
Illustrative p-aminophenolic compounds which are suitable for use as 
developing agents include N-methyl-p-aminophenol, p-aminophenol, 
N-(.beta.-hydroxyethyl)-p-aminophenol, N-(4-hydroxyphenyl)glycine, 
2-methyl-p-aminophenol and p-benzylaminophenol, with 
N-methyl-p-aminophenol being particularly preferable. 
The developing agents shown above are preferably used in amounts which 
generally range from 0.05 to 0.8 moles per liter. If dihydroxybenzenes are 
used in combination with 1-phenyl-3-pyrazolidones or p-aminophenols, the 
former is preferably used in an amount of from 0.05 to 0.5 moles per 
liter, while the latter is preferably used in an amount not exceeding 0.06 
moles per liter. 
Illustrative sulfites which is used as preservatives in the developer used 
in the present invention include sodium sulfite, potassium sulfite, 
lithium sulfite, ammonium sulfite, sodium bisulfite, potassium 
metabisulfite, and formaldehyde sodium bisulfite. Among of these, sodium 
sulfite and potassium sulfite are preferably used. These sulfites are 
preferably present in concentrations of 0.15 moles or more per liter, with 
concentrations of at least 0.4 moles per liter being more preferable. The 
upper limit of the sulfite content is preferably 2.5 moles per liter. 
In the present invention, alkaline agents may be used to achieve pH 
adjustment and pH adjusters or buffers such as sodium hydroxide, potassium 
hydroxide, sodium carbonate, potassium carbonate, tertiary sodium 
phosphate and terriary potassium phosphate may be used as alkaline agents. 
Other additives that may be incorporated in the silver halide photographic 
material of the present invention include development restrainers such as 
boric acid, borax, sodium bromide, potassium bromide and potassium iodide; 
organic solvents such as ethylene glycol, diethylene glycol, triethylene 
glycol, dimethylformamide, methyl cellosolve, hexylene glycol, ethanol and 
methanol; and anti-foggants or black pepper preventing agents such as 
mercapto compounds (e.g., 1-phenyl-5-mercaptotetrazole and 
2-mercaptobenzimidazole-5-sulfonic acid sodium salt), indazole compounds 
(e.g., 5-nitroindazole), and benzotriazole compounds (e.g., 
5-methyl-benzotriazole). If desired, the silver halide photographic 
material of the present invention may further contain other additives such 
as toning agents, surface active agents, defoaming agents, hard water 
softeners, hardening agents, and amino compounds as described in Japanese 
Patent Application (OPI) No. 106244/81. 
In accordance with the image-forming method of the present invention, 
negative images having super high contrast characteristics (.gamma.&gt;10) 
may be attained by rapid-access processing (development time ranging from 
15 to 60 seconds) with the stable developer described above. The 
temperature for processing in accordance with the method of the present 
invention is typically selected from the range of 18 to 50.degree. C. 
Fixing solutions having commonly employed formulations may be used in the 
present invention. Suitable fixing agents include are thiosulfates, 
thiocyanates, and any of the organic sulfur compounds that are known to be 
effective as fixing agents. The fixing solution may contain a 
water-soluble aluminum salt as a hardening agent. 
The photographic material of the present invention is preferably processed 
in an automatic developing machine, and, in this case, negative images 
having satisfactorily super high contrastcontrasty characteristics can be 
attained even if the total processing time during which the 
light-sensitive material fed is passed through the steps of development, 
fixing, washing, and drying, and is subsequently recovered in as short as 
90-120 seconds. 
The following examples are given for the purpose of further illustrating 
the present invention, but should in no sense be taken as limiting the 
invention. 
EXAMPLE 1 
An aqueous solution of silver nitrate and an aqueous solution of potassium 
bromide/potassium iodide were mixed by the double-jet method in the 
presence of ammonia while the pAg was kept at 7.9, so as to produce a 
monodisperse cubic silver iodobromide emulsion A (2 mol % AgI and 98 mol % 
AgBr) having an average grain size of 0.3 .mu.m. 
In a separate step, an aqueous solution of silver nitrate and an aqueous 
solution of potassium bromide were mixed by the double-jet method in the 
presence of ammonia while the pAg was held at 7.9, so as to produce a 
monodisperse cubic silver bromide emulsion B having an average grain size 
of 0.23 .mu.m. 
Silver bromide grains were prepared by the same method as used to prepare 
an emulsion B, and were subsequently sulfur-sensitized with sodium 
thiosulfate to produce a silver bromide emulsion C. 
An aqueous solution of silver nitrate and an aqueous solution of potassium 
bromide were mixed by the double-jet method in the presence of ammonia 
while the pAg was held at 7.9, so as to produce a monodisperse cubic 
silverbromide emulsion having an average grain size of 0.18 .mu.m. This 
emulsion was sulfur-sensitized with sodium thiosulfate to prepare an 
emulsion D. 
Each of the emulsions A, B, C and D was spectrally sensitized with 
6.times.10.sup.-4 moles, per mole of silver, of a sensitizing dye 
(5,5'-dichloro-3,3'-di(3-sulfopropyl)-9-ethyl-oxacarbocyanine sodium 
salt). To the sensitized emulsion, 
4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene was added as a stabilizer. 
To the emulsion samples identified by Nos. (1) to (16) in Table 1, an 
alkylbenzenesulfonate (surfactant) and a vinylsulfonic acid compound 
(hardening agent) were added, and the pH of each emulsion was subsequently 
adjusted to 5.8. 
To a polyethylene terephthalate support having a thickness of 100 .mu.m, 
one of the thus prepared emulsions was applied such that the total silver 
coated in O- and U-layers was 3.2 g/m.sup.2 and the applied emulsion 
layers was overlaid with a protective layer for a gelatin coated of 1 
g/m.sup.2. By repeating the same procedures, samples (1) to (16) having 
the data shown in Table 1 were prepared. The O-layer signifies an 
overlying layer which is the closer to the protective layer of the two 
emulsion layers, and the U-layer signifies an underlying layer which is 
the closer to the support. Both O- and U-layers contained the same amount 
of a hydrazine compound, I-12, per mole of silver. 
TABLE 1 
______________________________________ 
O-layer formulation 
U-layer formulation 
Compound Compound 
Sam- Silver I-12 Silver 
I-12 
ple Emul- coated (10.sup.-3 mol/ 
Emul- coated 
(10.sup.-3 mol/ 
No. sion (g/m.sup.2) 
mol Ag) sion (g/m.sup.2) 
mol Ag) 
______________________________________ 
1 A 3.2 0.5 -- -- -- 
2 B 3.2 0.5 -- -- -- 
3 C 3.2 0.5 -- -- -- 
4 D 3.2 0.5 -- -- -- 
5 A 1.6 3.0 B 1.6 3.0 
6 A 1.6 5.0 B 1.6 5.0 
7 A 0.8 3.0 B 2.4 3.0 
8 A 0.8 5.0 B 2.4 5.0 
9 A 1.6 3.0 C 1.6 3.0 
10 A 1.6 5.0 C 1.6 5.0 
11 A 0.8 3.0 C 2.4 3.0 
12 A 0.8 5.0 C 2.4 5.0 
13 A 1.6 3.0 D 1.6 3.0 
14 A 1.6 5.0 D 1.6 5.0 
15 A 0.8 3.0 D 2.4 3.0 
16 A 0.8 5.0 D 2.4 5.0 
______________________________________ 
Each of the thus prepared samples was exposed for 5 seconds under a 
tungsten lamp (3200.degree. K.) through a sensitometric optical wedge, and 
was subsequently developed at 38.degree. C. for 30 seconds with a 
developer having the formulation shown below. The developed sample was 
then fixed, washed with water, and dried. Development and subsequent 
processing were performed with an automatic developer, FG-660F, of Fuji 
Photo Film Co., Ltd. 
______________________________________ 
Developer formulation 
______________________________________ 
Hydroquinone 35.0 g 
N-methyl-p-aminophenol hemisulfate 
0.8 g 
Sodium hydroxide 9.0 g 
Tertiary potassium phosphate 
74.0 g 
Potassium sulfite 90.0 g 
Ethylenediaminetetraacetic acid 
1.0 g 
disodium salt 
Potassium bromide 3.0 g 
5-Methyl benzotriazole 0.6 g 
3-Diethylamino-1-propanol 
15.0 g 
Water to make 1000 ml 
(pH = 11.6) 
______________________________________ 
The photographic characteristics of the processed samples are shown in 
Table 2. 
The relative sensitivity data were represented in terms of the reciprocal 
of the amount of exposure necessary to provide a density of 1.5, with the 
value for sample (1) being taken as 100. The contrast (.gamma.) data were 
indicated in terms of the average gradation over the density range of from 
0.3 to 3.0. Evaluation of the occurrence of black peppers was conducted in 
the following manner: the number of black pepper spots that occurred in 
unexposed areas of a sample was counted under examination with a 
magnifying glass (.times.25) and rating was made on a five-score basis, 
with 5 being assigned to the samples which were substantially free from 
the occurrence of black pepper and 1 being assigned to those which were 
affected most severely. Scores of 3 and upward were taken to indicate 
levels acceptable for practical use. 
TABLE 2 
______________________________________ 
Relative 
Sample Sensiti- Contrast Black 
No. vity (.gamma.) 
D.sub.max 
pepper Remarks 
______________________________________ 
1 100 15.0 4.1 5 Comparison 
2 33 6.5 4.6 5 Comparison 
3 48 17.5 5.3 3 Comparison 
4 31 14.0 5.8 4 Comparison 
5 52 7.4 3.6 5 Comparison 
6 60 8.1 4.3 5 Comparison 
7 47 6.9 3.7 5 Comparison 
8 56 7.5 4.4 5 Comparison 
9 91 12.0 4.6 5 Invention 
10 98 16.5 4.8 5 Invention 
11 89 12.5 4.9 4 Invention 
12 95 17.0 5.1 4 Invention 
13 87 11.5 4.9 5 Invention 
14 93 13.5 5.1 5 Invention 
15 89 12.0 5.2 5 Invention 
16 95 14.5 5.6 4 Invention 
______________________________________ 
As is clear from Table 2, Sample Nos. 1 to 4, each having a single emulsion 
layer, exhibited a lower sensitivity (except for Sample No. 1) and 
D.sub.max than Sample Nos. 9 to 16, each having a double-layered emulsion 
coat. Sample Nos. 5 to 8, using emulsion B, which had a gamma value of 
less than 10, experienced a drop in sensitivity, and their final gamma 
values were also 10 or less. 
The data for Sample Nos. 12 and 16 show the following: by employing a dual 
structure wherein emulsion A and emulsion C or D were coated in two 
layers, a sensitivity that was substantially equal to that of the more 
sensitive emulsion A was attained, and a D.sub.max that was close to the 
higher-density emulsion C or D was attained; these effects became more 
pronounced as the ratio of C/A or D/A increased. 
As will be understood from the foregoing description, the silver halide 
photographic material of the present invention that contains a hydrazine 
derivative and which employs a multi-layered structure of two or more 
emulsions having different average grain sizes (as when a fine-grained 
emulsion and a coarse-grained emulsion are coated in two layers) exhibits 
the very useful advantage of reduced occurrence of black pepper while 
attaining a high optical density and contrast without sacrificing the high 
sensitivity. 
EXAMPLE 2 
By performing the formation of silver halide grains in the existence of 
(NH.sub.4).sub.3 RhCl.sub.6 and K.sub.3 IrCl.sub.6, an aqueous solution of 
silver nitrate and an aqueous solution of silver halide containing the 
rhodium salt of 1.times.10.sup.-6 mol/mol-Ag and the iridium salt of 
4.times.10.sup.-7 mol/mol-Ag were mixed by the double-jet method in the 
presence of ammonia while the pAg was kept at 7.9 under 45.degree. C. for 
60 minutes, so as to produce a monodisperse cubic silver chloroiodobromide 
emulsion (0.1 mol % AgI and 30 mol % AgBr) having an average grain size of 
0.25 .mu.m. 
This emulsion was washed with water to remove salts and then was 
sulfur-sensitized with sodium thiosulfate to prepare an emulsion E. 
An aqueous solution of silver nitrate and an aqueous solution of silver 
halide which are the same as the emulsion E, were mixed by the double-jet 
method in the presence of ammonia while the pAg was kept at 7.9 under 
40.degree. C. for 30 minutes, so as to produce a monodisperse cubic silver 
chloroiodobromide emulsion (0.1 mol % AgI and 30 mol % AgBr) having an 
average grain size of 0.19 .mu.m. 
This emulsion was washed with water to remove salts and then was 
gold/sulfur-sensitized to prepare an emulsion F. 
Each of the above emulsions E and F and the emulsion A used in Example 1 
was spectrally sensitized with 3.times.10.sup.-4 moles, per mole of 
silver, of 
1-(2-hydroxyethoxyethyl)-3-(pyridine-2-yl)-5-[(3-sulfobutyl-5-chloro-2-ben 
zooxsazolinidene)ethylidene]-2-thiohydantoine potassium salt as a 
sensitizing dye. 
To each of the sensitized emulsions, 1.5 g/mol-Ag of 
4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene, 2 g/mol-Ag of hydroquinone, 2 
g/mol-Ag of resolcine aldoxime, and 0.1 g/mol-Ag of 1-phenyl-5-mercapto 
tetrazole were added as a stabilizer, and further, a compound of the 
following formula: 
##STR2## 
and saponin (coating aid), a compound of the following formula: CH.sub.2 
.dbd.CHS0.sub.2 CH.sub.2 CONH(CH.sub.2).sub.n NHCOCH.sub.2 S0.sub.2 
CH.dbd.CH.sub.2 (n=2 or 3) (hardener), a polystyrenesulfonate (thickner), 
and a dispersion of polyethyl acrylate (latex polymer) were added. 
After a hydrazine compound I-12 was added thereto, 0-, M-, and U-layers and 
the protective layer which is composed of gelatin, 
dodecylbenzenesulfonate, silicone oil, colloidal silica, polyethyl 
acrylate, polymethyl methacrylate (average grain size: 2 .mu.m) and 
polystyrene sulfonic acid were coated on a support at the same time to 
prepare Sample Nos. 17 to 23 as shown in Table 3. 
The M-layer signifies an emulsion layer between O-layer and U-layer when 
three emulsion layers are applied to a support. 
TABLE 3 
__________________________________________________________________________ 
O-layer formation M-layer formation 
U-layer formation 
Compound Compound Compound 
Silver 
I-12 Silver 
I-12 Silver 
I-12 
Sample 
Emul- 
coated 
(10.sup.-3 mol/ 
Emul- 
coated 
(10.sup.-3 mol/ 
Emul- 
coated 
(10.sup.-3 mol/ 
No. sion 
(g/m.sup.2) 
mol-Ag) 
sion 
(g/m.sup.2) 
mol-Ag) 
sion 
(g/m.sup.2) 
mol-Ag) 
__________________________________________________________________________ 
17 A 3.2 5.0 -- -- -- -- -- -- 
18 E 3.2 0.8 -- -- -- -- -- -- 
19 F 3.2 0.2 -- -- -- -- -- -- 
20 A 1.6 5.0 F 1.6 0.2 -- -- -- 
21 F 1.6 0.2 A 1.6 5.0 -- -- -- 
22 A 1.0 5.0 E 1.1 0.8 F 1.1 0.2 
23 F 1.0 0.2 E 1.1 0.8 A 1.1 5.0 
__________________________________________________________________________ 
Each of the thus prepared samples was exposed, developed, fixed, washed 
with water, and dried in the same manner as described for Example 1. 
The photographic characteristics of the processed samples are shown in 
Table 4. 
TABLE 4 
______________________________________ 
Relative 
Sample Sensiti- Contrast Black 
No. vity (.gamma.) 
D.sub.max 
pepper Remarks 
______________________________________ 
17 100 16.0 3.8 5 Comparison 
18 52 15.5 4.9 3 Comparison 
19 48 17.0 5.4 2 Comparison 
20 98 16.5 5.0 5 Invention 
21 95 16.0 5.1 4 Invention 
22 95 17.0 5.1 5 Invention 
23 91 16.5 5.3 5 Invention 
______________________________________ 
As is clear from Table 4, Sample Nos. 20 to 23, each having two or three 
emulsion layers of the present invention, exhibited a higher D.sub.max 
than Sample No. 17 having a single emulsion layer and a higher sensitivity 
and a lower black pepper than Sample Nos. 18 and 19 having a single 
emulsion layer. 
While the invention has been described in detail and with reference to 
specific embodiments thereof, it will be apparent to one skilled in the 
art that various changes and modifications can be made therein without 
departing from the spirit and scope thereof.