Silver halide photographic light-sensitive materials

A silver halide photographic light-sensitive material is disclosed. The material is comprised of a support having provided thereon at least one silver halide emulsion layer which is coated with a surface protective layer. The silver halide emulsion layer includes an inside fogged silver halide emulsion and a light-sensitive silver halide emulsion containing silver halide grains which are tabular silver halide grains having a grain diameter which is 5 times or more the grain thickness. The material is highly sensitive and forms images which have high contrast and a high maximum density. The material can be developed in a relatively short developing time at a low temperature treatment without using additives.

FIELD OF THE INVENTION 
The present invention relates to silver halide photographic light-sensitive 
materials and, in greater detail, to silver halide photographic 
light-sensitive materials which have high sensitivity and which form 
images having a high contrast and a high maximum density. 
BACKGROUND OF THE INVENTION 
With respect to photographic images composed of silver, the ratio of 
optical density of images to the amount of silver composing the images per 
unit area is generally called covering power, which is a measure for 
valuation of optical efficiency of silver composing the images. The 
covering power of the silver halide photographic light-sensitive layer 
increases generally with reduction of the grain size of silver halide 
grains and decreases as the grain size increases. On the other hand, since 
the sensitivity of the silver halide emulsion layer generally becomes high 
with the increase of the grain size of silver halide grains, silver halide 
emulsions having a large grain size are used for producing photographic 
light-sensitive materials having a high sensitivity. Accordingly, the 
photographic light-sensitive materials having a high sensitivity require a 
large amount of silver per unit area in order to obtain a certain image 
density. In other words, it is needed for the material to contain a larger 
amount of silver salts per unit area of the photographic light-sensitive 
material in order to obtain both the high sensitivity and the required 
maximum image density. This is the actual state that the prior 
photographic light-sensitive materials having a high sensitivity are 
encountered. 
One attempt at improving the covering power while maintaining high 
sensitivity involves adding various polymers to a high-speed coarse silver 
halide emulsion. Such techniques have been described in British Pat. Nos. 
1,048,057 and 1,039,471 and U.S. Pat. Nos. 3,043,697 and 3,446,618. They 
are all insufficient, because though the covering power is improved more 
or less, the strength of the coating film deteriorates. Particularly, in 
an automatic developing machine which is now conventionally used, when a 
photographic material having a coating film of poor strength is used, part 
of the gelatin in the film dissolves in a developing solution or a fixing 
solution and adheres to conveying rolls in the automatic developing 
machine. Accordingly, pollution of photographic images is caused by 
transferring to the light-sensitive material. 
On the other hand, U.S. Pat. Nos. 2,996,382 and 3,178,282 have disclosed 
that photographic images having a high contrast and a high covering power 
are obtained at high sensitivity using silver halide photographic 
light-sensitive materials wherein surface latent image type coarse silver 
halide grains and fine silver halide grains having fog nuclei in the 
inside thereof are contained in the same layer or in adjacent layers. 
However, this method is not desirable because development requires a long 
period of time in conventional low temperature treatment in order to 
obtain a sufficiently high density and a high contrast at high 
sensitivity, and the desired effect cannot be obtained with conventional 
high temperature rapid treatment. 
Attempts at eliminating these disadvantages involve introducing various 
additives such as rhodan, imidazoles, thioethers, etc. into 
light-sensitive materials or processing solutions. (For example, U.S. Pat. 
No. 2,996,382 and Japanese Patent Application (OPI) Nos. 78535/82 and 
89749/82. The term "OPI" as used herein refers to a "published unexamined 
Japanese patent application".) However, it is obvious that any means for 
improving the above described disadvantages without adding the additives 
is more preferred. 
SUMMARY OF THE INVENTION 
Accordingly, an object of the present invention is to provide silver halide 
photographic light-sensitive materials which have a high sensitivity and 
which form images having a high contrast and a high maximum density. 
Another object of the present invention is to shorten the developing time 
in the low temperature treatment without using additives and to give a 
property capable of carrying out the high temperature rapid treatment. 
As a result of earnest studies in order to attain the above described 
objects, the present inventors have found that they can be attained by 
providing the following photographic light-sensitive materials. 
Namely, it has been found that they can be attained by providing silver 
halide photographic light-sensitive materials comprising a support having 
provided thereon at least one silver halide emulsion layer and a surface 
protective layer covering the silver halide emulsion layer, wherein the 
silver halide photographic light-sensitive materials contain a 
light-sensitive silver halide emulsion and an inside fogged silver halide 
emulsion, and silver halide grains contained in the light-sensitive silver 
halide emulsion are tabular silver halide grains having a diameter of 5 
times or more of the thickness thereof. 
DETAILED DESCRIPTION OF THE INVENTION 
The term "light-sensitive" in the present invention means that the 
sensitivity of the light-sensitive silver halide emulsion is higher than 
that of the inside fogged silver halide emulsion. In greater detail, it 
means that the light-sensitive silver halide emulsion has a sensitivity of 
10 or more times higher, preferably 100 or more times higher, than the 
sensitivity of the inside fogged silver halide emulsion. 
Sensitivity used here is defined similarly to the sensitivity as described 
later. 
As the light-sensitive silver halide emulsions, conventional silver halide 
emulsions such as a surface latent image type emulsions, etc. are used. 
The surface latent image type silver halide emulsion used here means an 
emulsion wherein the sensitivity obtained by surface development (A) is 
larger than the sensitivity obtained by internal development (B) and, 
preferably, the sensitivity of the former is two or more times higher than 
that of the latter, when the emulsion is developed by the surface 
development (A) and the internal development (B) after exposed to light 
for 1 to 1/100 second. The sensitivity used here is defined as follows: 
EQU S=100/Eh 
wherein S represents sensitivity, and Eh represents exposed amount 
necessary to obtain the middle density of maximum density (Dmax) and 
minimum density (Dmin): 1/2(Dmax+Dmin). 
[Surface development (A)] 
Development is carried out in a developing solution having the following 
formulation at 20.degree. C. for 10 minutes. 
______________________________________ 
N--Methyl-p-aminophenol (hemisulfate) 
2.5 g 
Ascorbic acid 10 g 
Sodium metaborate tetrahydrate 
35 g 
Potassium bromide 1 g 
Water to make 1 l 
______________________________________ 
[Internal development (B)] 
After the light-sensitive material is treated in a bleaching solution 
containing potassium ferricyanide 3 g/l and phenosafranine 0.0126 g/l at 
about 20.degree. C. for 10 minutes and washed with water for 10 minutes, 
it is developed in a developing solution having the following formulation 
at 20.degree. C. for 10 minutes. 
______________________________________ 
N--Methyl-p-aminophenol (hemisulfate) 
2.5 g 
Ascorbic acid 10 g 
Sodium metaborate tetrahydrate 
35 g 
Potassium bromide 1 g 
Sodium thiosulfate 3 g 
Water to make 1 l 
______________________________________ 
As the light-sensitive silver halide emulsion in the present invention, 
silver halide emulsions containing tabular silver halide grains are used. 
As silver halide grains contained in the light-sensitive emulsion, tabular 
silver halide grains are used, but the ratio of the tabular silver halide 
grains used is preferred to be 10% by weight or more, preferably 
50.degree. C. by weight or more, based on the weight of all the silver 
halide grains. 
In the following, the tabular silver halide grains used in the present 
invention is described. 
The tabular silver halide grains in the present invention have a 
diameter/thickness ratio of 5 or more, preferably 5 to 100, more 
preferably 5 to 50, and particularly 7 to 20. 
The diameter of the tabular silver halide grains used here means the 
diameter of a circle having the same area as the projected area of the 
grain. In the present invention, the diameter of the tabular silver halide 
grains is preferred to be in a range of 0.5 to 10 .mu.m, more preferably 
0.5 to 5.0 .mu.m, and particularly preferably 1.0 to 4.0 .mu.m. 
Generally, the tabular silver halide grains are plates having two parallel 
faces. Accordingly, the term "thickness" in the present invention means 
the distance between two parallel faces composing the tabular silver 
halide grain. 
The tabular silver halide grains are preferred to have a halogen 
composition of silver bromide or silver iodobromide, and preferably silver 
iodobromide having a silver iodide content of 0 to 10% by mol. 
In the following, the process for producing the tabular silver halide 
grains is described. 
The tabular silver halide grains can be produced by suitably combining 
methods known in this field. 
For example, they are obtained by a process which comprises forming seed 
crystals in which tabular grains are present in an amount of 40% by weight 
or more, in an atmosphere of pBr 1.3 or less and a comparatively high pAg 
value, and adding a silver salt solution and a halide solution at the same 
time with keeping the pBr value at the above described value to grow the 
seed crystals. 
It is preferred to add the silver salt solution and the halide solution so 
as not to generate fresh crystal nuclei in the process of growing grains. 
The size of the tabular silver halide grains can be controlled by control 
of temperature, selection of the solvent or amount thereof, and control of 
rates of adding silver salts and halides used for growing grains. 
In production of the tabular silver halide grains of the present invention, 
if desired, a silver halide solvent can be used, by which it is possible 
to control grain size, shape of grains (ratio of diameter/thickness, 
etc.), distribution of grain size and rate of growth of grains. The 
solvent is preferred to be used in an amount of 10.sup.-3 to 1.0% by 
weight, more preferably 10.sup.-2 to 10.sup.-1 % by weight, based on the 
reaction solution. 
For example, the distribution of grain size becomes a state of 
monodispersed system and the rate of growth can be increased with increase 
of the amount of the solvent. On the other hand, the thickness of grains 
tends to increase with the increase of the amount of the solvent. 
Examples of silver halide solvents which are frequently used include 
ammonia, thioethers and thioureas. Concerning thioethers, U.S. Pat. Nos. 
3,271,157, 3,790,387 and 3,574,628, etc. can be referred to. 
In production of the tabular silver halide grains of the present invention, 
in order to accelerate growth of grains, methods of increasing the rates 
of adding a silver salt solution (for example, an aqueous solution of 
AgNO.sub.3) and a halide solution (for example, an aqueous solution of 
KBr), the amounts of them and the concentrations of them are suitably 
used. 
Concerning these methods, for example, British Pat. No. 1,335,925, U.S. 
Pat. Nos. 3,672,900, 3,650,757 and 4,242,445, and Japanese Patent 
Application (OPI) Nos. 142329/80 and 158124/80 can be referred to. 
The surface latent image type silver halide emulsions may contain grains 
having a regular crystal form such as a cube or octahedron, grains having 
an irregular crystal form such as a sphere, or grains having a composite 
crystal form of them, besides the above described tabular silver halide 
grains. These silver halide grains are preferred to have an average grain 
size larger than that of silver halide emulsions having fog nuclei in the 
inside. They preferably have an average grain size of 0.6 .mu.m or more. 
The distribution of grain size may be broad or narrow. 
Further, as silver halide, it is possible to use silver chloroiodide, 
silver iodobromide, silver chloride, silver chlorobromide, silver bromide 
and silver chloroiodobromide. Further, as the silver halide, those having 
a silver iodide content of 0 to 10% by mol, such as silver iodobromide, 
are particularly preferred. 
Photographic emulsions containing these grains can be prepared by processes 
as described in P. Glafkides, Chimie et Physique Photographique, published 
by Paul Montel Co., (1967), G. F. Duffin, Photographic Emulsion Chemistry, 
published by The Focal Press, (1966), and V. L. Zelikman et al, Making and 
Coating Photographic Emulsion, published by The Focal Press, (1964), etc. 
Namely, any of an acidic process, a neutral process and an ammonia process 
may be used. Further, as a type of reacting soluble silver salts with 
soluble halides, any of a one-side mixing process, a simultaneous mixing 
process and a combination of them may be used. 
It is possible to use a process of forming grains in the presence of excess 
silver ions (the so-called back mixing process). As a type of the 
simultaneous mixing process, it is possible to use a process of keeping 
pAg in the liquid phase where silver halide is formed at a constant value, 
namely, the so-called controlled double-jet process, too. 
According to this process, silver halide emulsions having a regular crystal 
form and a nearly uniform grain size are obtained. 
Two or more silver halide emulsions prepared respectively may be used as a 
mixture. 
Formation of silver halide grains such as tabular silver halide grains used 
in the present invention or physical ageing of them may be carried out in 
the presence of cadmiun salts, zinc salts, lead salts, thallium salts, 
iridium salts or complex salts thereof, rhodium salts or complex salts 
thereof, or iron salts or iron complex salts, etc. 
Soluble salts are generally removed from the light-sensitive silver halide 
emulsions used in the present invention after formation of precipitates or 
after physical ageing. As means for removal, it is possible to use a 
noodle water wash process well-known hitherto in which gelatin is 
gelatinized, or a flocculation process utilizing inorganic salts composed 
of polyvalent anions such as sodium sulfate, anionic surface active 
agents, anionic polymers (for example, polystyrenesulfonic acid) or 
gelatin derivatives (for example, aliphatic acylated gelatin, aromatic 
acylated gelatin, or aromatic carbamoyl gelatin, etc.). The process of 
removal of soluble salts may be omitted. 
As the light-sensitive silver halide emulsions, the so-called primitive 
emulsions which are not chemically sensitized can be used, but they are 
generally chemically sensitized. In order to carry out chemical 
sensitization, it is possible to use processes as described in the above 
described literature written by Glafkides or Zelikman et al, and Die 
Grundlagen der Photographischen Prozesse mit Silberhalogeniden, edited by 
H. Frieser (Akademische Verlagsgesellshaft, 1968). 
Namely, a sulfur sensitization process using a sulfur containing compound 
capable of reacting with silver ion, a reduction sensitization process 
using a reducing substance and a noble metal sensitization process using a 
gold or other noble metal compound can be used alone or as a combination 
of them. As sulfur sensitizers, thiosulfates, thioureas, thiazoles, 
rhodamines and other compounds can be used, examples of which have been 
described in U.S. Pat. Nos. 1,574,944, 2,410,689, 2,278,947, 2,728,668, 
3,656,955, 4,032,928 and 4,067,740. As reducing sensitizers, stannous 
salts, amines, hydrazine derivatives, formamidine sulfinic acid, silane 
compounds, etc. can be used. Examples of them have been described in U.S. 
Pat. Nos. 2,487,850, 2,419,974, 2,518,698, 2,983,609, 2,983,610, 
2,694,637, 3,930,867 and 4,054,458. In order to carry out noble metal 
sensitization, not only gold complex salts but also complex salts of 
metals of group VIII in the periodic table such as platinum, iridium or 
palladium, etc. can be used. Examples of them have been described in U.S. 
Pat. Nos. 2,399,083 and 2,448,060 and British Pat. No. 618,061, etc. 
In the photographic light-sensitive materials of the present invention, 
various kinds of hydrophilic colloids can be used as a binder. 
As colloids used for such a purpose, there are hydrophilic colloids 
conventionally used in the photographic field, for example, gelatin, 
colloidal albumin, polysaccharide, cellulose derivatives and synthetic 
resins such as polyvinyl compounds including polyvinyl alcohol 
derivatives, or acrylamide polymers, etc. Hydrophobic colloids, for 
example, dispersed polymerized vinyl compounds and, particularly, those 
which increase dimensional stability of photographic materials, may be 
contained together with the hydrophilic colloids. Suitable examples of 
such compounds include water insoluble polymers produced by polymerizing 
vinyl monomers such as alkyl acrylates, alkyl methacrylates, acrylic acid, 
sulfoalkyl acrylates, or sulfoalkyl methacrylates, etc. 
In order to prevent deterioration of sensitivity in the process of 
producing the sensitive materials, during preservation or during treatment 
of the sensitive materials, various compounds can be added to the above 
described photographic emulsions. Examples of such compounds include 
heterocyclic compounds including 
4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene, 3-methyl-benzothiazole and 
1-phenyl-5-mercaptotetrazole, mercury containing compounds, mercapto 
compounds and metal salts, etc. Those compounds have been known hitherto. 
Examples of some useful compounds include those as described in K. Mees, 
The Theory of the Photographic Process (3rd edition, 1966) with citing 
original literatures, and in U.S. Pat. Nos. 1,758,576, 2,110,178, 
2,131,038, 2,173,628, 2,697,040, 2,304,962, 2,324,123, 2,394,198, 
2,444,605 to 2,444,608, 2,566,245, 2,694,716, 2,697,099, 2,708,162, 
2,728,663 to 2,728,665, 2,476,536, 2,824,001, 2,843,491, 2,886,437, 
3,052,544, 3,137,577, 3,220,839, 3,226,231, 3,236,652, 3,251,691, 
3,252,799, 3,287,135, 3,326,681, 3,420,668, and 3,622,339, and British 
Pat. Nos. 893,428, 403,789, 1,173,609 and 1,200,188, etc. 
Further, as the silver halide emulsions having fog nuclei in the inside 
thereof used for producing the light-sensitive materials of the present 
invention, there are emulsions which give a transmission fog density 
(excluding the density of the support itself) of 0.5 or less when a test 
sample prepared by applying the emulsion to a transparent support so as to 
be 2 g/m.sup.2 calculated as silver is developed with D-19 (a developing 
solution designated by Eastman Kodak Co.) at 35.degree. C. for 2 minutes 
without exposing to light and gives a transmission fog density (excluding 
the density of the support itself) of 1.0 or more when the same test 
sample is developed with a developing solution prepared by adding 0.5 g/l 
of potassium iodide to D-19 at 35.degree. C. for 2 minutes without 
exposing to light. 
The silver halide emulsions having fog nuclei in the inside thereof can be 
prepared by various known processes. Processes for fogging include a 
process which comprises irradiating to light or X-rays, a process which 
comprises forming chemically fogged nuclei with a reducing agent, a gold 
compound or a sulfur containing compound, etc., and a process which 
comprises producing the emulsion under a condition of low pAg and high pH. 
In order to form fog nuclei in only the inside, there is a process which 
comprises bleaching fog nuclei on the surface of silver halide grains with 
a solution of potassium ferricyanide after both the inside and the surface 
of the grains are fogged by the above described processes, but it is 
preferred to use a process which comprises preparing a core emulsion 
having fog nuclei under a condition of low pAg and high pH or by 
chemically fogging, and thereafter covering the core emulsion with a shell 
emulsion. This process for preparing a core-shell emulsion is known and a 
description is present in, for example, U.S. Pat. No. 3,206,313. 
Further, control of the depth of inside fog nuclei from the surface can be 
easily carried out by changing the conditions (for example, time, 
temperature and concentration of the solution, etc.) of bleaching the 
surface fog nuclei with a solution of potassium ferricyanide. Further, in 
the core-shell emulsions, the position of inside fog nuclei can be easily 
controlled by controlling the amount of the shell emulsion (namely, 
thickness). 
Further, the inside fog nuclei of the inside fogged grains is preferred to 
be present in an average depth of 0.02 .mu.m or more from the surface of 
the grains to prevent fogging and stains forming during fixation. 
The silver halide emulsions having fog nuclei in the inside have an average 
grain size smaller than that of the surface latent image type silver 
halide emulsions, and they are preferred to have an average grain size of 
0.05 to 1.0 .mu.m, more preferably 0.1 to 0.6 .mu.m, and particularly 
preferably 0.1 to 0.5 .mu.m. 
The grain size of silver halide grains which are not tabular or plate-like 
means the diameter of the grain in case that the grain is spherical or 
nearly spherical or the diameter of a grain having the same volume in case 
that the grain has another form (for example, cube or octahedron, etc.). 
Further, in the inside fogged silver halide emulsion, any of silver 
bromide, silver iodobromide, silver iodochlorobromide, silver 
chlorobromide and silver chloride may be used. 
The ratio of the light-sensitive silver halide to the inside fogged silver 
halide in the silver halide photographic light-sensitive materials of the 
present invention can be varied according to the kind of emulsions used 
(for example, compositions of halides), the kind of utility of the 
light-sensitive material used, or the contrast of the emulsions used, 
etc., but it is preferred to be in a range of 100:1 to 1:100 and 
particularly preferably, 10:1 to 1:10. Further, the amount of silver 
coated is preferred to be in a range of 0.5 to 8 g per m.sup.2. 
With respect to layer construction of the photographic materials according 
to the present invention, there are several embodiments. Typical 
embodiments are described in the following. There are (1) a construction 
which is prepared by applying a mixed emulsion composed of tabular silver 
halide grains of the present invention and inside fogged silver halide 
grains to a support and applying a protective layer to the resulting 
layer, (2) a construction which is prepared by applying first an emulsion 
containing inside fogged silver halide grains to a support applying an 
emulsion containing tabular silver halide grains of the present invention 
to the resulting layer and applying a protective layer to the resulting 
layer, (3) a construction which is prepared by applying first a mixed 
emulsion composed of tabular silver halide grains of the present invention 
and inside fogged silver halide grains to a support, applying an emulsion 
containing tabular silver halide grains of the present invention to the 
resulting layer, and applying a protective layer to the resulting layer, 
(4) a construction which is prepared by applying a mixed emulsion of 
tabular silver halide grains of the present invention, conventional 
light-sensitive silver halide grains and inside fogged silver halide 
grains of the present invention to a support, and applying a protective 
layer to the resulting layer, (5) a construction which is prepared by 
applying first a mixed emulsion composed of tabular silver halide grains 
of the present invention and inside fogged silver halide grains to a 
support, applying a conventional light-sensitive silver halide emulsion to 
the resulting layer, and applying a protective layer to the resulting 
layer, and (6) a construction which is prepared by applying first an 
emulsion containing inside fogged silver halide grains to a support, 
applying an emulsion containing tabular silver halide grains of the 
present invention to the resulting layer, applying an emulsion containing 
the conventional light-sensitive silver halide grains to the resulting 
layer, and applying a protective layer to the resulting layer. 
However, the present invention is not limited to them, and the above 
described constructions may be provided on both sides of the support, and 
the silver halide emulsion layer may be separated into three or more 
emulsion layers each having a different distribution of spectral 
sensitivity. 
When the light-sensitive materials of the present invention are developed 
in the presence of one or more selected from tetrazaindenes having at 
least one mercapto group, purines having at least one mercapto group, 
triazaindenes having at least one mercapto group and pentazaindenes having 
at least one mercapto group, prevention of fogs and prevention of 
irregular stains, etc. are effectively carried out. Examples, of these 
compounds include the following. 
##STR1## 
The amount of them to be added is preferred to be in a range of 
1.times.10.sup.-5 to 1.times.10.sup.-1 mols/mol-silver halide and, 
preferably, 1.times.10.sup.-4 to 1.times.10.sup.-2 mols/mol-silver halide. 
Further, development acceleration of the light-sensitive materials of the 
present invention can be carried out by adding a compound represented by 
the following general formula (I) to any of elements provided on the 
support: 
EQU A--S--S--B (I) 
wherein A and B, which may be identical or different, each represents an 
alkyl group, an aralkyl group, an aryl group, a heterocyclic group, or 
##STR2## 
in which R represents an alkyl group, an aryl group, an aralkyl group, a 
heterocyclic group or an amino group. Examples of these compounds include: 
##STR3## 
A protective layer of the silver halide photographic light-sensitive 
material of the present invention is a layer composed of a hydrophilic 
colloid. Those exemplified above can be used as the hydrophilic colloid 
used herein. The protective layer may be of single layer or multilayer 
structure. 
To the emulsion layer or the protective layer of the silver halide 
photographic light-sensitive material of the present invention, and 
preferably to the protective layer, matting agents and/or smoothing agents 
may be added. Examples of the matting agents include organic compounds 
such as water dispersive vinyl polymers having a suitable grain size 
(those having a grain size of 0.3 to 5 .mu.m or those having a grain size 
of two times or more, preferably four times or more, of the thickness of 
the protective layer are preferred to use) such as polymethyl 
methacrylate, etc. and inorganic compounds such as silver halides or 
strontium barium sulfate, etc. The smoothing agents not only serve for 
preventing troubles caused by adhesion, likewise the matting agents, but 
also are effective for improving friction characteristics which have 
relation to camera adaptability in case of photographing or projecting 
movie films. Examples of them include liquid paraffins, waxes such as 
higher fatty acid esters, etc., polyfluorinated hydrocarbons and 
derivatives thereof, and silicones such as polyalkyl polysiloxanes, 
polyaryl polysiloxanes, polyalkylaryl polysiloxanes or alkylene oxide 
addition derivatives of them, etc. 
In the silver halide photographic light-sensitive material of the present 
invention, an antihalation layer, an intermediate layer and a filter 
layer, etc. may be provided as occasion demands. 
In the light-sensitive material of the present invention, the photographic 
silver halide emulsion layers and other hydrophilic colloid layers can be 
hardened with suitable hardening agents. Examples of these hardening 
agents include vinyl sulfonyl compounds, hardening agents having an active 
halogen, dioxane derivatives and oxypolysaccharides such as oxystarch, 
etc., as described in Japanese Patent Application (OPI) Nos. 76025/78, 
76026/78 and 77619/78. 
To the photographic silver halide emulsion layers, it is possible to add 
other additives. Particularly useful additives for the photographic 
emulsions include lubricants, sensitizers, light absorbing dyes and 
plasticizers, etc. 
Further, in the present invention, compounds which release iodine ion (for 
example, potassium iodide, etc.) may be contained in the silver halide 
emulsion, and desired images may be obtained with a developing solution 
containing iodine ions. 
In the light-sensitive material of the present invention, the hydrophilic 
colloid layers may contain water soluble dyes as filter dyes or for the 
purpose of preventing irradiation, preventing halation or for other 
various purposes. Examples of such dyes include oxonol dyes, hemioxonol 
dyes, styryl dyes, merocyanine dyes, cyanine dyes and azo dyes. 
Particularly, oxonol dyes, hemioxonol dyes and merocyanine dyes are 
useful. 
In the light-sensitive material of the present invention, in case that dyes 
and ultraviolet ray absorbers, etc. are contained in the hydrophilic 
colloid layers, they may be mordanted with cationic polymers. For example, 
it is possible to use polymers as described in British Pat. No. 685,475, 
U.S. Pat. Nos. 2,675,316, 2,839,401, 2,882,156, 3,048,487, 3,184,309 and 
3,445,231, German Offenlegungsschrift No. 1,914,362 and Japanese Patent 
Application (OPI) Nos. 47624/75 and 71332/75. 
The light-sensitive material of the present invention may contain surface 
active agents for various purposes. Any of nonionic, ionic and ampholytic 
surface active agents can be used depending on the purpose. For example, 
there are polyoxyalkylene derivatives and amphoteric amino acids 
(including sulfobetaines), etc. Such surface active agents have been 
described in U.S. Pat. Nos. 2,600,831, 2,271,622, 2,271,623, 2,275,727, 
2,787,604, 2,816,920 and 2,739,891 and Belgium Pat. No. 652,862. 
In the light-sensitive material of the present invention, the photographic 
emulsions may be spectrally sensitized with sensitizing dyes so as to be 
sensitive to blue light having comparatively long wave lengths, green 
light, red light or infrared light. As the sensitizing dyes, it is 
possible to use cyanine dyes, merocyanine dyes, complex cyanine dyes, 
complex merocyanine dyes, holopolar cyanine dyes, styryl dyes, hemicyanine 
dyes, oxonol dyes and hemioxonol dyes, etc. 
Useful sensitizing dyes used in the present invention have been described 
in, for example, U.S. Pat. Nos. 3,522,052, 3,619,197, 3,713,828, 
3,615,643, 3,615,632, 3,617,293, 3,628,964, 3,703,377, 3,666,480, 
3,667,960, 3,679,428, 3,672,897, 3,769,026, 3,556,800, 3,615,613, 
3,615,638, 3,615,635, 3,705,809, 3,632,349, 3,677,765, 3,770,449, 
3,770,440, 3,769,025, 3,745,014, 3,713,828, 3,567,458, 3,625,698, 
2,526,632 and 2,503,776, Japanese Patent Application (OPI) No. 76525/73 
and Belgium Pat. No. 691,807, etc. 
The sensitizing dyes in the present invention are used in the same 
concentration as conventional negative type silver halide emulsions. It is 
particularly advantageous to use them in a dye concentration so as not to 
substantially deteriorate inherent sensitivity of the silver halide 
emulsions. It is preferred to use the sensitizing dyes in a range of about 
1.0.times.10.sup.-5 to 5.times.10.sup.-4 mols per mol of silver halide 
and, more preferably, about 4.times.10.sup.-5 to 2.times.10.sup.-4 mols 
per mol of silver halide. 
In the photographic light-sensitive material of the present invention, the 
photographic emulsion layers and other layers are provided on one side or 
both sides of an elastic support conventionally used for photographic 
light-sensitive materials. Examples of useful elastic supports include 
films composed of synthetic polymers such as cellulose acetate, cellulose 
acetate butyrate or polyethylene terephthalate, and papers coated or 
laminated with a barita layer or a .alpha.-olefin polymer (for example, 
polyethylene, etc.). 
In the photographic light-sensitive material of the present invention, the 
photographic emulsion layers and other hydrophilic colloid layers can be 
applied to the support or other layer by various known coating methods. 
Application can be carried out using a dip coating method, a roll coating 
method, a curtain coating method or an extrusion coating method, etc. 
Methods as described in U.S. Pat. Nos. 2,681,294, 2,761,791 and 3,526,528 
are advantageous to use. 
The present invention can be applied to any photographic light-sensitive 
material, if it requires a high sensitivity or a high contrast. For 
example, the present invention can be used for X-ray photographic 
light-sensitive materials, litho-type photographic light-sensitive 
materials, black-white negative photographic light-sensitive materials, 
color negative light-sensitive materials and color paper light-sensitive 
materials, etc. 
Further, it is possible to use for diffusion transfer light-sensitive 
materials which form positive images by dissolving an unexposed silver 
halide to precipitate it on an image receiving layer adjacent to the 
silver halide emulsion layer, and color diffusion transfer light-sensitive 
materials, etc. 
Photographic processing of the light-sensitive materials of the present 
invention can be carried out by known methods using known processing 
solutions as described in, for example, Research Disclosure, No. 176, 
pages 28-30 (RD-17643). This photographic processing may be any of 
photographic processing for forming silver images (black-white 
photographic processing) and photographic processing for forming dye 
images (color photographic processing) according to the purpose. The 
processing temperature is generally selected from a range of 18.degree. C. 
to 50.degree. C., but it may be lower than 18.degree. C. or higher than 
50.degree. C. 
For example, developing solution used in case of carrying out black-white 
photographic processing may contain known developing agents. As the 
developing agents, dihydroxybenzenes (for example, hydroquinone), 
3-pyrazolidones (for example, 1-phenyl-3-pyrazolidone) and aminophenols 
(for example, N-methyl-p-aminophenol), etc. can be used alone or as a 
combination of them. The light-sensitive material of the present invention 
can be processed with a developing solution containing imidazoles as a 
silver halide solvent as described in Japanese Patent Application (OPI) 
No. 78535/82. Further, they can be processed with a developing solution 
containing a silver halide solvent and additives such as indazoles or 
triazoles, etc. as described in Japanese Patent Application (OPI) No. 
37643/82. The developing solutions usually further contain known 
preservatives, alkali agents, pH buffer agents, and antifogging agents. If 
necessary, they may still further contain dissolution assistants, toning 
agents, development accelerators, surface active agents, defoaming agents, 
water softeners, hardening agents and thickeners, etc. 
The photographic emulsions of the present invention can be subjected to the 
so-called "litho-type" development processing. "Litho-type" development 
processing means the development processing in which the development is 
infectiously carried out under a low sulfurous acid ion concentration 
using dihydroxybenzenes as a developing agent in order to obtain 
photographic reproduction of line drawings or photographic reproduction of 
halftone images with dots (as described in detail in Mason, Photographic 
Processing Chemistry, pages 163-165 (1966)). 
As a specific type of development processing, it is possible to use a 
process which comprises developing a light-sensitive material containing a 
developing agent in, for example, an emulsion layer with an aqueous 
solution of alkali. Of the developing agents, hydrophobic developing 
agents can be introduced into the emulsion layers by various methods as 
described in Research Disclosure, No. 169 (RD-16928), U.S. Pat. No. 
2,739,890, British Pat. No. 813,253 and German Pat. No. 1,547,763, etc. 
Such development processing may be combined with silver salt stabilization 
treatment using thiocyanates. 
As fixing solutions, those having a conventionally used composition can be 
used. As fixing agents, not only thiosulfates and thiocyanates but also 
organic sulfur compounds which are known to have an effect as the fixing 
agent can be used. The fixing solutions may contain water soluble aluminum 
salts as a hardening agent.

EXAMPLE 1 
(1) Preparation of spherical light-sensitive silver halide emulsion for 
comparison 
A spherical silver iodobromide emulsion (AgI: 2% by mol) having an average 
grain size of 1.3 .mu.m was prepared from silver nitrate, potassium 
bromide and potassium iodide by a conventional ammonia process. The 
emulsion was desalted by a conventional precipitation process and 
chemically sensitized by a gold sulfur sensitization method using 
chloroaurate and sodium thiosulfate, and 
4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene as a stabilizer was added 
thereto to obtain a spherical light-sensitive silver iodobromide emulsion 
A for comparison. 
(2) Preparation of tabular light-sensitive silver halide emulsion for 
comparison 
A tabular silver iodobromide emulsion (AgI: 2% by mol) having an average 
diameter of 1.3 .mu.m and an average diameter/thickness ratio of 3.7 was 
prepared from silver nitrate, potassium bromide and potassium iodide using 
thioether (HO(CH.sub.2).sub.2 S(CH.sub.2).sub.2 S(CH.sub.2).sub.2 OH) with 
reference to U.S. Pat. Nos. 3,271,157, 3,790,387 and 3,574,628. The 
emulsion was desalted and chemically sensitized by the same manner as in 
(1) above, and 4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene as a stabilizer 
was added thereto to obtain a tabular light-sensitive silver iodobromide 
emulsion B for comparison. 
(3) Preparation of tabular light-sensitive halide emulsion of the present 
invention 
A tabular silver iodobromide emulsion (AgI: 2% by mol) having an average 
diameter of 1.63 .mu.m and an average diameter/thickness ratio of 11.6 was 
prepared from silver nitrate, potassium bromide and potassium iodide by 
the same manner as in (2) above except that the amount of thioether 
(HO(CH.sub.2).sub.2 S(CH.sub.2).sub.2 S(CH.sub.2).sub.2 OH) was varied. 
The emulsion was desalted and chemically sensitized by the same manner as 
in (2) above, and 4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene as a 
stabilizer was added thereto to obtain a tabular light-sensitive silver 
iodobromide emulsion C of the present invention. 
(4) Preparation of inside fogged emulsion 
An aqueous solution of potassium bromide and an aqueous solution of silver 
nitrate were added at the same time to a 2 wt% aqueous solution of gelatin 
kept at 55.degree. C. to prepare silver bromide core grains having an 
average grain size of 0.326 .mu.m. Subsequently, the temperature was 
raised to 75.degree. C., and silver nitrate and sodium hydroxide were 
added thereto to carry out ageing for 15 minutes, whereby the surface of 
core grains was chemically fogged. The pH and pAg were then returned to 
the original values, and the temperature was reduced to 55.degree. C. 
Subsequently, an aqueous solution of silver bromide and an aqueous 
solution of silver nitrate were added at the same time over such a period 
of time that the average grain size became 0.370 .mu.m to deposit a shell 
on the fogged core grains. The resulting emulsion was desalted by a 
conventional precipitation process and dispersed again in a solution of 
gelatin to obtain an inside fogged emulsion D. 
(5) Production of comparative samples 1 to 5 
An emulsion layer composed of each of the light-sensitive silver halide 
emulsions A, B and C prepared in (1), (2) and (3) above and a protective 
layer composed of an aqueous solution of gelatin were uniformly applied in 
turn to a polyester support which had been subjected to undercoating 
treatment, to produce comparative samples 1, 3 and 5. In these cases, the 
coating silver amount of the light-sensitive silver halide emulsion was 
1.7 g/m.sup.2, the coating amount of gelatin in the protective layer was 
1.3 g/m.sup.2, and the coating amount of gelatin in the emulsion layer was 
2.2 g/m.sup.2. 
Each of the light-sensitive silver halide emulsions A and B was then 
blended with the inside fogged emulsion D. A layer composed of the 
resulting mixed solution and a protective layer composed of an aqueous 
solution of gelatin were uniformly applied in turn to the same support to 
produce comparative samples 2 and 4. In these cases, the coating silver 
amount of the light-sensitive silver halide emulsions A and B was 1.7 
g/m.sup.2, the coating silver amount of the inside fogged emulsion D was 
1.7 g/m.sup.2, the coating amount of gelatin in the protective layer was 
1.3 g/m.sup.2, and the coating amount of gelatin in the emulsion layer was 
2.2 g/m.sup.2. 
(6) Production of sample 6 of the present invention 
An emulsion layer composed of a mixture of the light-sensitive silver 
halide emulsion C prepared in (3) above and the inside fogged emulsion D 
prepared in (4) above and a protective layer composed of an aqueous 
solution of gelatin were uniformly applied in turn to a polyester support 
which had been subjected to undercoating treatment to produce a sample 6 
of the present invention. In this case, the coating silver amount of the 
light-sensitive silver halide emulsion C was 1.7 g/m.sup.2, the coating 
silver amount of the inside fogged emulsion D was 1.7 g/m.sup.2, the 
coating amount of gelatin in the protective layer was 1.3 g/m.sup.2, and 
the coating amount of gelatin in the emulsion layer was 2.2 g/m.sup.2. 
(7) 
After the comparative samples 1 to 5 and the sample 6 of the present 
invention as prepared above were exposed to light wedge, they were 
developed with a developing solution A having the following formulation at 
20.degree. C. for 4 minutes, followed by fixing, washing with water and 
drying. They were then subjected to sensitometry. 
______________________________________ 
Formulation of developing solution A 
______________________________________ 
1-Phenyl-3-pyrazolidone 0.5 g 
Hydroquinone 20.0 g 
Disodium ethylenediaminetetraacetate 
2.0 g 
Potassium sulfite 60.0 g 
Boric acid 4.0 g 
Potassium carbonate 20.0 g 
Sodium bromide 20.0 g 
Diethylene glycol 30.0 g 
Water to make 1 l 
NaOH to make pH 1.0 
______________________________________ 
The results are shown in Table 1. 
TABLE 1 
______________________________________ 
Photographic Properties 
Emulsion Maxi- 
Sample (coating silver 
Relative mum Gam- 
No. amount: g/m.sup.2) 
Sensitivity 
Density 
ma Fog 
______________________________________ 
1 Emulsion A 100 0.7 0.4 0.05 
(Compar- 
(1.7) 
ison) 
2 Emulsion A + 
100* 0.9 0.4 0.05 
(Compar- 
Emulsion D 
ison) (1.7 + 1.7) 
3 Emulsion B 100 0.8 0.5 0.05 
(Compar- 
(1.7) 
ison) 
4 Emulsion B + 
100** 1.0 0.5 0.05 
(Compar- 
Emulsion D 
ison) (1.7 + 1.7) 
5 Emulsion C 100 1.0 0.8 0.05 
(Compar- 
ison) 
6 Emulsion C + 
160*** 2.1 2.1 0.05 
(Inven- 
Emulsion D 
tion) (1.7 + 1.7) 
______________________________________ 
*based on the sensitivity of Sample 1 being 100 
**based on the sensitivity of Sample 3 being 100 
***based on the sensitivity of Sample 5 being 100 
Table 1 clearly shows that with comparative samples 2 and 4 the maximum 
density only slightly increased with the conventional low temperature 
treatment as compared with comparative samples 1 and 3, and the effect of 
improving relative sensitivity and gamma cannot be observed. On the 
contrary, in sample 6 of the present invention, the relative sensitivity, 
the maximum density and the gamma were remarkably improved as compared 
with comparative sample 5. Namely, when tabular silver halide grains 
having a diameter of 5 times or more of the thickness are used as the 
light-sensitive silver halide emulsion, images which were excellent in 
sensitivity, maximum density and gamma can be obtained by the conventional 
low temperature treatment. This fact means that the development time can 
be shortened, because the desired effect can be obtained by development 
for a definite time. 
EXAMPLE 2 
After the comparative samples 1 to 5 and the sample 6 of the present 
invention prepared in Example 1 were exposed to light wedge, they were 
developed with a developing solution B having the following formulation at 
35.degree. C. for 25 seconds, followed by fixing, washing with water and 
drying. They were then subjected to sensitometry. 
______________________________________ 
Formulation of developing solution B 
______________________________________ 
Potassium hydroxide 29.14 g 
Glacial acetic acid 10.96 g 
Potassium sulfite 44.20 g 
Sodium bicarbonate 7.50 g 
Boric acid 1.00 g 
Diethylene glycol 28.96 g 
Ethylenediaminetetraacetic acid 
1.67 g 
5-Methylbenzotriazole 0.06 g 
5-Nitroindazole 0.25 g 
Hydroquinone 30.00 g 
Potassium bromide 14.00 g 
1-Phenyl-3-pyrazolidone 1.50 g 
Glutaraldehyde 4.93 g 
Sodium metabisulfite 12.60 g 
Water to make 1 l 
______________________________________ 
The pH was adjusted to 10.25. 
The results are shown in Table 2. 
TABLE 2 
______________________________________ 
Photographic Properties 
Emulsion Maxi- 
Sample (coating silver 
Relative mum Gam- 
No. amount: g/m.sup.2) 
Sensitivity 
Density 
ma Fog 
______________________________________ 
1 Emulsion A 100 0.8 0.4 0.05 
(Compar- 
(1.7) 
ison) 
2 Emulsion A + 
105* 1.4 0.7 0.05 
(Compar- 
Emulsion D 
ison) (1.7 + 1.7) 
3 Emulsion B 100 1.0 0.6 0.05 
(Compar- 
(1.7) 
ison) 
4 Emulsion B + 
105** 1.6 1.1 0.05 
(Compar- 
Emulsion D 
ison) (1.7 + 1.7) 
5 Emulsion C 100 1.3 1.0 0.05 
(Compar- 
ison) 
6 Emulsion C + 
150*** 2.8 2.3 0.05 
(Inven- 
Emulsion D 
tion) (1.7 + 1.7) 
______________________________________ 
*based on the sensitivity of Sample 1 being 100 
**based on the sensitivity of Sample 3 being 100 
***based on the sensitivity of Sample 5 being 100 
Table 2 clearly shows that the sensitivity, the maximum density and the 
gamma in the comparative samples 2 and 4 were not sufficiently improved in 
the conventional high temperature rapid treatment, in comparison with the 
comparative samples 1 and 3. On the contrary, sample 6 of the present 
invention showed a sufficiently high sensitivity, a sufficiently high 
maximum density and a sufficiently high gamma as compared with the 
comparative sample 5. Thus the effect of the present invention is 
remarkable. 
EXAMPLE 3 
(1) Preparation of inside fogged emulsion containing mercaptotetrazaindene 
An aqueous solution of potassium bromide and an aqueous solution of silver 
nitrate were added at the same time to a 2 wt% aqueous solution of gelatin 
kept at 55.degree. C. to prepare silver bromide core grains having an 
average grain size of 0.290 .mu.m. The temperature was raised to 
75.degree. C., and silver nitrate and sodium hydroxide were added thereto 
to carry out ageing for 15 minutes, whereby the surface of core grains was 
chemically fogged. Then, the pH and pAg were returned to the original 
values by adding acetic acid and potassium bromide, and the temperature 
was reduced at 55.degree. C. Subsequently, an aqueous solution of silver 
bromide and an aqueous solution of silver nitrate were added at the same 
time over such a period of time that the average grain size became 0.370 
.mu.m to deposit a shell on the fogged core grains. The resulting emulsion 
was desalted by a conventional precipitation process and dispersed again 
in an aqueous solution of gelatin. Then, mercaptotetrazaindene compound A 
having the following formula was added in an amount of 1.7.times.10.sup.-3 
mols per mol of silver halide to obtain an inside fogged emulsion E. 
##STR4## 
(2) Production of comparative sample 7 
An emulsion layer composed of the tabular light-sensitive silver halide 
emulsion C prepared in Example 1-(3) and a protective layer composed of an 
aqueous solution of gelatin were applied uniformly in turn to a polyester 
support which had been subjected to undercoating treatment to produce a 
comparative sample 7. 
In this case, the coating silver amount of the emulsion C was 3.4 
g/m.sup.2, the coating amount of gelatin in the protective layer was 1.3 
g/m.sup.2, and the coating amount of gelatin in the emulsion layer was 2.2 
g/m.sup.2. 
(3) Production of sample 8 of the present invention 
An emulsion layer composed of a mixture of the tabular silver halide 
emulsion C prepared in Example 1-(3) and the inside fogged emulsion E 
prepared in (1) above and a protective layer composed of an aqueous 
solution of gelatin were uniformly applied to the same support in turn to 
produce a sample 8 of the present invention. 
In this case, the coating silver amount of the emulsion C was 1.7 
g/m.sup.2, the coating silver amount of the emulsion E was 1.7 g/m.sup.2, 
the coating amount of gelatin in the protective layer was 1.3 g/m.sup.2 m 
and the coating amount of gelatin in the emulsion layer was 2.2 g/m.sup.2. 
(4) 
After the comparative sample 7 and the sample 8 of the present invention 
were exposed to light wedge, they were developed with the developing 
solution A as described in Example 1 at 20.degree. C. for 4 minutes, 
followed by fixing, washing with water and drying. They were then 
subjected to sensitometry. 
The results are shown in Table 3. 
TABLE 3 
______________________________________ 
Photographic Properties 
Emulsion Maxi- 
Sample (coating silver 
Relative mum Gam- 
No. amount: g/m.sup.2) 
Sensitivity 
Density 
ma Fog 
______________________________________ 
7 Emulsion C 100 1.9 1.8 0.08 
(Compar- 
(3.4) 
ison) 
8 Emulsion C + 
170 2.2 2.3 0.03 
(Inven- 
Emulsion E 
tion) (1.7 + 1.7) 
______________________________________ 
Table 3 clearly shows that the present invention is also effective when 
used in combination with compound A. 
Example 4 
(1) Production of comparative sample 9 
An emulsion layer composed of a mixture of the spherical light-sensitive 
silver halide emulsion prepared in Example 1-(1) and the tabular 
light-sensitive silver halide emulsion C prepared in Example 1-(3) and a 
protective layer composed of an aqueous solution of gelatin were uniformly 
applied in turn to a polyester support which had been subjected to 
undercoating treatment to produce a comparative sample 9. In this case, 
the coating silver amount of the emulsion A was 0.85 g/m.sup.2, the 
coating silver amount of the emulsion C was 0.85 g/m.sup.2, the coating 
amount of gelatin in the protective layer was 1.3 g/m.sup.2, and the 
coating amount of gelatin in the emulsion layer was 2.2 g/m.sup.2. 
(2) Production of samples 10, 11 and 12 of the present invention 
An emulsion layer composed on only the inside fogged emulsion D prepared in 
Example 1-(4), an emulsion layer composed of only the tabular 
light-sensitive silver halide emulsion C prepared in Example 1-(3) and a 
protective layer composed of an aqueous solution of gelatin were uniformly 
applied in turn to a polyester support which had been subjected to 
undercoating treatment to produce a sample 10 having three layers of the 
present invention. In this case, the coating silver amount of the emulsion 
D in the lower emulsion layer was 1.7 g/m.sup.2, the coating silver amount 
of the emulsion C in the upper emulsion layer was 1.7 g/m.sup.2, the 
coating amount of gelatin in the protective layer was 1.3 g/m.sup.2, the 
coating amount of gelatin in the upper emulsion layer was 1.1 g/m.sup.2, 
and the coating amount of gelatin in the lower emulsion layer was 1.1 
g/m.sup.2. 
Then, an emulsion layer composed of a mixture of the tabular 
light-sensitive silver halide emulsion C prepared in Example 1-(3) and the 
inside fogged emulsion D prepared in Example 1-(4), an emulsion layer 
composed of only the tabular light-sensitive silver halide emulsion C 
prepared in Example 1-(3) and a protective layer composed of an aqueous 
solution of gelatin were uniformly applied to the same support in turn to 
produce a sample 11 of the present invention. In this case, the coating 
silver amount of the emulsion C in the lower emulsion layer was 0.85 
g/m.sup.2, the coating silver amount of the emulsion D in the lower 
emulsion layer was 1.7 g/m.sup.2, the coating silver amount of the 
emulsion C in the upper emulsion layer was 0.85 g/m.sup.2, the coating 
amount of gelatin in the protective layer was 1.3 g/m.sup.2, the coating 
amount of gelatin in the upper emulsion layer was 0.55 g/m.sup.2, and the 
coating amount of gelatin in the lower emulsion layer was 1.65 g/m.sup.2. 
Further, an emulsion layer composed of a mixture of the spherical 
light-sensitive silver halide emulsion A prepared in Example 1-(1), the 
spherical light-sensitive silver halide emulsion C prepared in Example 
1-(3) and the inside fogged emulsion D prepared in Example 1-(4) and a 
protective layer composed of an aqueous solution of gelatin were uniformly 
applied to the same support in turn to produce a sample 12 of the present 
invention. In this case, the coating silver amount of the emulsion A was 
0.85 g/m.sup.2, the coating silver amount of the emulsion C was 0.85 
g/m.sup.2, the coating silver amount of the emulsion D was 1.7 g/m.sup.2, 
the coating amount of gelatin in the protective layer was 1.3 g/m.sup.2, 
and the coating amount of the gelatin in the emulsion layer was 2.2 
g/m.sup.2. 
(3) 
After the comparative sample 5 prepared in Example 1, the above described 
comparative sample 9 and the samples 10 to 12 of the present invention 
were exposed to light wedge, they were developed with the developing 
solution A as described in Example 1 at 20.degree. C. for 4 minutes, 
followed by fixing, washing with water and drying. Then, they were 
subjected to sensitometry. 
The results are shown in Table 4. 
TABLE 4 
______________________________________ 
Photographic Properties 
Emulsion Maxi- 
Sample (coating silver 
Relative mum Gam- 
No. amount: g/m.sup.2) 
Sensitivity 
Density 
ma Fog 
______________________________________ 
5 Emulsion C 100 1.0 0.8 0.05 
(Compar- 
(1.7) 
ison) 
10 Upper layer: 
160* 2.1 2.0 0.05 
(Inven- 
Emulsion C 
tion) (1.7) 
Lower layer: 
Emulsion D 
(1.7) 
11 Upper layer: 
160* 2.1 2.1 0.05 
(Inven- 
Emulsion C 
tion) (0.85) 
Lower layer: 
Emulsion C + 
Emulsion D 
(0.85 + 1.7) 
9 Emulsion A + 
100 0.85 0.6 0.05 
(Compar- 
Emulsion C 
ison) (0.85 + 0.85) 
12 Emulsion A + 
150** 1.9 1.9 0.05 
(Inven- 
Emulsion C + 
tion) Emulsion D 
(0.85 + 0.85 + 
1.7) 
______________________________________ 
*based on the sensitivity of Sample 5 being 100 
**based on the sensitivity of Sample 9 being 100 
Table 4 clearly shows that the present invention is effective even if the 
emulsion layer has a multilayer construction. Further, it is understood 
that the present invention is effective even if tabular silver halide 
grains are used together with spherical silver halide grains. 
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.