Silver halide light sensitive photographic material

A silver halide light sensitive photographic material is disclosed, comprising a support having thereon a silver halide emulsion layer containing tabular grains having an aspect ratio of not less than 5 and an even number of parallel twin planes, the tabular grains further satisfying the following requirements: PA1 (A) a coefficient of variation of grain size being 20% or less, PA1 (B) 0.7.ltoreq.y/x.ltoreq.2.0, where x represent a coefficient of variation of twin plane spacing and y represents a coefficient of variation of grain thickness, and (C) the grains having, in the interior of the grain, an internal layer having an iodide content higher than that of the grain surface, and the iodide content of the grain surface being higher than an average overall iodide content of the grains.

FIELD OF THE INVENTION 
The present invention relates to a silver halide light sensitive 
photographic material and in particular to a silver halide light sensitive 
photographic material with high sensitivity and superior graininess, and 
improved in pressure resistance and high intensity reciprocity failure 
characteristics. 
BACKGROUND OF THE INVENTION 
Recently, with the spread of compact cameras, autofocus single-lens reflex 
cameras and film-incorporated cameras, there has been a strong demand for 
a silver halide color photographic material with high sensitivity and 
superior image quality. Consequently, need for improvement of photographic 
performance of silver halide emulsions has also become severe, and further 
higher level requirements for photographic performance including high 
speed, superior graininess and sharpness have also been made. 
In response to these demands, U.S. Pat. Nos. 4,434,226; 4,439,520; 
4,414,310; 4,433,048; 4,414,306 and 4,459,353 disclose techniques of using 
tabular silver halide grains, which is known to bring about advantages 
such as enhancement of sensitivity including enhanced spectral 
sensitization efficiency with a sensitizing dye, improved 
sensitivity/graininess, improved sharpness and covering power due to 
specific optical property of the tabular silver halide grains. 
JP-A 7-191425 (herein, the term "JP-A" is referred to as unexamined, 
published Japanese Patent Application) describes tabular silver halide 
grains with an aspect ratio of less than 5 and being internally 
reduction-sensitized, in which a variation coefficient of twin plane 
spacing (x) and a variation coefficient of grain thickness(y) meet the 
relationship, 0.7.ltoreq.y/x.ltoreq.2.0. These tabular grains, however, 
were found to provide insufficient response to recent high level 
requirements, and still further enhanced photographic performance is 
desired. 
Relating to this trend of higher speed and higher image quality, the demand 
for improvement in pressure characteristics of silver halide light 
sensitive photographic materials continuously increases. There have been 
attempts for improving pressure characteristics by various means, in which 
techniques of enhancing resistance to stress of silver halide grains is 
generally thought to be preferable and valid in practice, rather than 
techniques of incorporating additives such as a plasticizer. In response 
to this demand, there have been extensively studied photographic emulsions 
comprised of core/shell type silver halide grains having a high iodide 
silver iodobromide stratum. In particular, there is paid attention on a 
silver iodobromide emulsion comprised of core/shell type grains internally 
having a high iodide phase containing 10 mol % or more iodide. 
Techniques of improving pressure characteristics of core/shell type grains 
are disclosed in JP-A 59-99433, 60-35726, and 60-147727. JP-A 63-220238 
and 1-201649 also disclose techniques of improving graininess, pressure 
characteristics and exposure intensity dependence as well as sensitivity 
by introducing dislocation lines within the grain. Further, JP-A 6-235988 
discloses multilayered structure type, monodisperse tabular silver halide 
grains having a high iodide intermediate layer. These techniques, however, 
are still insufficient to meet recent high level requirements as a silver 
halide emulsion with high sensitivity, superior graininess and improved 
pressure characteristics. 
As a technique of controlling the charge carrier within the silver halide 
grain, such as a free electron and positive hole, is known a metal-doping 
technique. For example, Leubner reported that doping of an iridium complex 
into the silver halide exhibited an electron-trap property The Journal of 
Photographic Science Vol.31, 93 (1983)!. JP-A 3-15040 discloses an iridium 
ion-containing silver halide emulsion, in which iridium ions are not 
present on the surface of silver halide grains and also a preparation 
method thereof. JP-A 6-175251 discloses a technique of improving both 
sensitivity and reciprocity law failure characteristics at 1/100 sec. 
exposure with in-plane epitaxial grains, in which an iridium compound is 
incorporated during the course of preparing the grains. JP-A 8-160559 
discloses a technique of improving high intensity reciprocity failure 
characteristics with tabular silver halide grains in which less than 1/20 
of the total content of a polyvalent metal compound (mol/mol of AgX) is 
contained in the outermost surface layer. However, any of these techniques 
is still insufficient in providing a photographic material with the 
sensitivity, image quality and high intensity reciprocity failure 
characteristics required in the market. 
SUMMARY OF THE INVENTION 
In view of the foregoing circumstances, it is an object of the present 
invention to provide a silver halide light sensitive photographic material 
and in particular a silver halide light sensitive photographic material 
with high sensitivity and superior graininess, and improved pressure 
resistance and high intensity reciprocity failure characteristics. 
The above object of the invention can be accomplished by the following 
constituent. 
A silver halide light sensitive photographic material comprising a support 
having thereon a silver halide emulsion layer containing silver halide 
grains, wherein at least 50% of the total projected area of silver halide 
grains contained in the emulsion layer is accounted for by tabular grains 
having an aspect ratio of 5 or more and an even number of twin planes 
parallel to the major face, the tabular grains meeting the following 
requirements: 
(A) a variation coefficient of grain size of 20% or less, 
(B) 0.7.ltoreq.y/x.ltoreq.2.0, where x represent a coefficient of variation 
of spacing between at least two twin planes, and y represents a 
coefficient of variation of grain thickness, and 
(C) the grains having an internal layer having a silver iodide content 
higher than that of the grain surface, and the silver iodide content of 
the grain surface being higher than the average silver iodide content of 
the grains; 
the tabular silver halide grains preferably having 5 or more dislocation 
lines; more preferably, the tabular grains containing a polyvalent metal 
compound and the surface of the grains containing the polyvalent metal 
compound of 1/20 or more of the average content of the grains (mol/mol of 
AgX). 
DETAILED EXPLANATION OF THE INVENTION 
A silver halide light sensitive photographic material according to the 
invention, comprises a support having thereon a silver halide emulsion 
layer containing silver halide grains, wherein at least 50% of the total 
projected area of silver halide grains contained in the emulsion layer is 
accounted for by tabular grains having an aspect ratio of 5 or more and an 
even number of twin planes parallel to the major face, the tabular grains 
meeting the following requirements (A), (B) and (C). 
The requirements (A), (B) and (C) will now be further explained. 
(A) The coefficient of variation of the size of the tabular grains 
according to the invention is to be 20% or less. The tabular grains are 
classified crystallographically as twin crystal grains. The twin crystal 
refers to silver halide crystal having one or more twin planes. 
Classification of forms of twin crystal grains is detailed in Klein & 
Moisar, Photographishe Korrespondenz, vol. 99, p 100 and ibid vol. 100 p 
57. 
The grain size of the tabular grains according to the invention is 
represented in terms of a circle equivalent diameter of the projected area 
of the grain (i.e., diameter of a circle having an area identical to the 
projected area of the silver halide grain). The grain size is preferably 
between 0.1 and 5.0 .mu.m and more preferably 0.2 to 2.0 .mu.m. The grain 
size of the tabular grains can be determined by magnifying the grains 
10,000 to 70,000 times in an electron microscope, taking a photograph 
thereof and measuring the grain diameter or grain projected area on the 
print. The number of measured grains is at random 1,000 or more. Herein, 
the average grain diameter is defined as diameter (ri) at the time when 
ni.multidot.ri.sup.3 becomes maximum, where ni is the frequency of grains 
with a diameter ri. (significant figure is three digits with the least 
digit being rounded off). 
The tabular grains relating to the invention are preferably monodispersed. 
A monodispersed silver halide grain emulsion is one in which the weight of 
silver halide grains included within the range of the grain diameter of 
.+-.20% of the average grain diameter is preferably not less than 60% of 
the total weight of grains, more preferably not less than 70%, and still 
more preferably not less than 89%. 
Alternatively, the monodispersed grains are those in which the distribution 
width of the grain size (coefficient of variation of grain size), as 
defined below, is preferably not less than 20%, more preferably not less 
than 15% and still more preferably not less than 12%: 
Coefficient of variation of grain size (%)=(Standard deviation/average 
grain size).times.100 where the average grain size and the standard 
deviation are determined based on the ri defined above. 
(B) A coefficient of variation of the spacing between twin planes (x) of 
tabular grains and a coefficient of variation of the thickness (y) satisfy 
the following requirement: 
EQU 0.7.ltoreq.y/x.ltoreq.2.0 
Tabular grains according to the invention have an even number of twin 
planes parallel to the major faces, and the twin planes can be observed 
with a transmission electron microscope. More concretely, a sample is 
prepared by coating a silver halide emulsion on a support so as to allow 
the major faces of silver halide grains to be oriented parallel to the 
support. The sample is sliced to a thickness of ca. 0.1 .mu.m by using a 
diamond cutter. The slice is observed with a transmission electron 
microscope to confirm the presence of twin planes. In the invention, the 
spacing between twin planes (i.e., twin plane spacing) is defined as a 
shortest distance selected from the distances between adjacent 
even-numbered twin planes in the tabular grain. A mean twin plane spacing 
of tabular grains can be obtained by arbitrarily selecting 1,000 or more 
grains exhibiting a section vertical to the major face and arithmetically 
averaging the twin plane spacings of the grains. In the invention, 
"coefficient of variation of a twin plane spacing (x)" indicates the 
extent of fluctuation in the twin plane spacings of the grains and is 
defined as the standard deviation of the twin plane spacing divided by the 
mean twin plane spacing, expressed in terms of percentage. The mean twin 
plane spacing, according to the invention, is preferably 0.01 to 0.05 
.mu.m and more preferably 0.013 to 0.03 .mu.m. 
The thickness of the tabular grains can be determined by observing the 
grains with an transmission electron microscope. The mean grain thickness 
can be obtained by averaging the thickness of each grain. The mean grain 
thickness of the tabular grains is preferably 0.05 to 1.5 .mu.m and more 
preferably 0.15 to 1.0 m. In the invention, a coefficient of variation of 
grain thickness represents an extent of variation (or fluctuation) of the 
thickness of the tabular grains, and defined as the standard deviation of 
grain thickness divided by the mean grain thickness, expresssed as a 
percentage. 
The tabular grains used in the invention satisfy the following relationship 
between the coefficient of variation of twin plane spacing (x) and the 
coefficient of variation of grain thickness (y), 
0.7.ltoreq.y/x.ltoreq.2.0, more preferably 0.8.ltoreq.y/x.ltoreq.1.6 and 
furthermore preferably 0.9.ltoreq.y/x.ltoreq.1.3. When y/x is less than 
0.7, variation of the twin plane spacing is too large, sufficient 
sensitivity and graininess can not be obtained. When y/x is more than 2.0, 
the variation of the grain thickness is too large, whereby sufficient 
sensitivity and graininess can not be achieved. 
According to the invention, the twin plane spacing can be controlled by 
optimally selecting parameters affecting supersaturation at the time of 
nucleation, such as gelatin concentration, gelatin type, temperature, 
iodide concentration, pBr, pH, ion-supplying rate and stirring rate. In 
general, the twin plane spacing can be shorted by performing nucleation 
under highly supersatuarated conditions. Details regarding the parameters 
of super-saturation are referred to JP-A 3-92924 and 1-213637. 
In the invention, to bring the value of y/x into the range of the 
invention, the following embodiment is preferred. 
(1) A low molecular weight gelatin having an average molecular weight of 
60,000 or less (preferably 20,000 or less) is employed at the stage of the 
nucleation, and a polyalkyleneoxide block copolymer is concurrently 
present. 
(2) In the nucleation process, in general, non-twinned crystal grains or 
non-parallel multi-twinned crystal grains other than fine tabular nucleus 
grains are likely to be produced. To allow fine grains, other than the 
tabular nucleus grains, to prevent from forming as much as possible, it is 
preferred to perform ripening by raising the temperature by 20 to 
60.degree. C. (preferably, 25 to 40.degree. C.) from the nucleating 
temperature, after completion of the nucleation. Further, to enhance 
monodispersibility of the grains, the temperature-raising time is 
preferably shortened, more preferably not more than 2.5 min./.degree.C. 
and still more preferably, not more than 1.5 min./.degree.C. 
(C) The tabular grains used in the invention have a layer in the interior 
of the grain which has an iodide content higher than that of the grain 
surface, and the iodide content of the grain surface is higher than the 
average overall content of the grains. 
In the invention, the grain surface of the tabular grains is referred to as 
an outermost layer including the outermost surface, having a depth 50 
.ANG. from the outermost surface. Halide composition of the surface of the 
tabular grains can be determined by the XPS method (X-ray Photoelectron 
Spectroscopy). 
A sample was cooled to -115.degree. C. or lower under a super-high vacuum 
of 1.times.10.sup.-8 torr or less, exposed to X-ray of Mg-K.alpha. line 
generated at an X-ray source voltage of 15 kV and an X-ray source current 
of 40 mA and measured with respect to Ag3d5/2, Br3d and I3d3/2 electrons. 
From the integrated intensity of a measured peak which has been corrected 
with a sensitivity factor, the halide composition of the surface can be 
determined. The XPS method is known as a technique of measuring the iodide 
content of the surface of silver halide grains, as disclosed in JP-A 
2-24188. When measured at room temperature, however, X-ray irradiation 
destroys a sample so that the iodide content of the outermost surface 
could not be accurately determined. The inventors of the present invention 
succeeded in accurate determination of the iodide content of the surface 
by cooling the sample to a temperature at which no destruction of the 
sample occurred. As a result, it is proved that, in core/shell grains 
which have a different composition between the interior and the surface, 
and grains in which a high iodide (or low iodide) layer is localized in 
the surface region, a value measured at room temperature is quite 
different from the true composition, due to decomposition of silver halide 
and diffusion of the halide (particularly, iodide). 
Procedure of the XPS method employed in the invention is as follows. To an 
emulsion is added a 0.05% by weight proteinase aqueous solution and 
stirred at 45.degree. C. for 30 min. to degrade the gelatin. After 
centrifuging and sedimenting the emulsion grains, the supernatant is 
removed. Then, distilled water is added thereto and the grains are 
redispersed. The resulting solution is coated on the mirror-finished 
surface of a silicon wafer to prepare a sample. Using the thus prepared 
sample, measurement of the surface iodide was conducte by the XPS method. 
In order to prevent sample destruction due to X-ray irradiation, the 
sample was cooled to -110 to -120.degree. C. in a measuring chamber, 
exposed to X-ray of Mg-K.alpha. line generated at an X-ray source voltage 
of 15 kV and an X-ray source current of 40 mA and measured with respect to 
Ag3d5/2, Br3d and I3d3/2 electrons. From the integrated intensity of a 
measured peak which has been corrected with a sensitivity factor, the 
halide composition of the surface can be determined. In the invention, the 
interior of the grain is referred to as an internal region within the 
grain in a depth of 50 .ANG. or more from the outermost surface. 
The difference in the iodide content between the surface and an internal 
high iodide layer of the tabular grains is preferably not less than 2 mol 
% and more preferably not less than 4 mol %. The iodide content of the 
surface of the tabular grains is preferably 2.6 to 16 mol % and more 
preferably 3 to 10 mol %. The tabular grains according to the invention 
have an internal layer having a higher iodide content than that of the 
grain surface, however, the position thereof is not specifically limited. 
The volume of the internal high iodide containing layer is preferably 1 to 
50% and more preferably 5 to 20%, based on silver of the total grains. 
The tabular grains used in the invention meet the requirement that the 
iodide content of the grain surface is higher than the average iodide 
content of the grains. The ratio of the surface iodide content to the 
average iodide content is preferably 1.3 to 30, and more preferably 1.5 to 
15. The tabular grains used in the invention are mainly comprised of 
silver iodobromide, and may have other silver halide composition, such as 
silver chloride, within a range which has no impairing effects of the 
invention. 
In the invention, at least 50% of the projected area of the total grains 
contained in at least one emulsion layer is accounted for by tabular 
grains having even-numbered twin planes and an aspect ratio of 5 or more. 
The tabular grains each have preferably 5 or more dislocation lines, more 
preferably 10 or more dislocation lines and furthermore preferably 20 to 
100 dislocation lines. The dislocation line according to the invention 
means an edge-form lattice defect, in which a boundary between a slipped 
region and non-slipped region is formed on the slip plane of the crystal. 
The dislocation lines in tabular grains can be directly observed by means 
of transmission electron microscopy at a low temperature, for example, in 
accordance with methods described in J. F. Hamilton, Phot. Sci. Eng. 11 
(1967) 57 and T. Shiozawa, Journal of the Society of Photographic Science 
and Technology of Japan, 35 (1972) 213. Silver halide tabular grains are 
taken out from an emulsion while making sure not to exert any pressure 
that causes dislocation in the grains, and they are placed on a mesh for 
electron microscopy. The sample is observed in transmission electron 
microscopy, while cooled to prevent the grain from being damaged (e.g., 
printing-out) by electron beam. Since electron beam penetration is 
hampered as the grain thickness increases, sharper observation is obtained 
when using an electron microscope of high voltage type (over 200 KV for 
0.25 .mu.m thick grains). From the thus-obtained electron micrograph, the 
position and number of the dislocation lines in each grain can be 
determined, when viewed perpendicularly to the major face. 
The tabular grains relating to the invention preferably have 5 or more 
dislocation lines within the grain. It is preferable that at least 50% of 
the total projected area of the tabular grains contained in the emulsion 
layer is accounted for by grains having 5 or more dislocation lines. Thus, 
when transmission electronmicrographs of silver halide grains contained in 
the emulsion layer are taken and therefrom, at random at least 500 tabular 
grains are extracted, in which the presence of the dislocation line(s) can 
be observed, the sum of the projected area of the grains having not less 
than 5 dislocation lines, which exceeds the sum of the projected area of 
the grains having less than 5 dislocation lines. 
With respect to the position of the dislocation lines in the tabular grains 
relating to the present invention, it is preferable that the dislocation 
lines exist in the fringe portions of the major face. The term, "fringe 
portion" refers to the peripheral portion of the major face of the tabular 
grain. More specifically, when a straight line is drawn outwardly from the 
center of gravity of the projection area projected from the major 
face-side, the dislocation lines exist in a region beyond 50% of the 
distance (L) between the intersection of a straight line with the 
periphery and the center, preferably, 70% or outer and more preferably 80% 
or outer. (In other words, the dislocation lines are located in the region 
between 0.5 L and L outwardly from the center of each grain, preferably 
between 0.7 L and L, more preferably between 0.8 L and L.) 
The method for introducing the dislocation lines into the silver halide 
grain is optional. The dislocation lines can be introduced by various 
methods, in which, at a desired time of introducing the dislocation lines 
during the course of forming silver halide grains, an iodide (e.g., 
potassium iodide) aqueous solution is added, along with a silver salt 
(e.g., silver nitrate) solution and without addition of a halide other 
than iodide by a double jet technique, silver iodide fine grains are 
added, only an iodide solution is added, or a compound capable of 
releasing an iodide ion disclosed in JP-A 6-11781 (1994) is employed. 
Among these, it is preferable to add iodide and silver salt solutions by a 
double jet technique, or to add silver iodide fine grains or an iodide ion 
releasing compound, as an iodide source. It is more preferable to add 
silver iodide fine grains. In this case, the number of the dislocation 
lines can be controlled by varying the addition amount of the potassium 
iodide aqueous solution, iodide ion-releasing compound or silver iodide 
fine grains, taking account of the size or aspect ratio of silver halide 
grains, the composition of silver halide grains at the time of addition 
and the pBr within the reaction vessel. More concretely, the addition 
amount is preferably 0.2 to 10 mol % and more preferably 0.5 to 5 mol %, 
based on silver of the total grains. It is also possible to control the 
position of the dislocation lines to be introduced by optimally selecting 
the method for introducing the dislocation lines, the composition of the 
surface of the tabular grains or the pBr within the reaction vessel, or 
alternatively by using a material capable of being adsorbed onto the 
tabular grains, such as a crystal habit-controlling agent. It is 
preferable to introduce the dislocation lines at a time after 50% 
(preferably 60%) of the total silver salt is added and before 95% 
(preferably 80%) of the total silver salt is added, during the course of 
forming silver halide grains used in the invention. 
The tabular grains used in the invention preferably contain a polyvalent 
metal compound (preferably, in the interior of the grain). The polyvalent 
metal compound is contained in the surface of the tabular grains, 
preferably in an amount of not less than 1/20(more preferable, not less 
than 1/10) of the total content of the metal compound (mol/mol of AgX). 
A polyvalent metal is selected from the group consisting of Mg, Al, Ca, Sc, 
Ti, V, Cr, Mn, Fe, Co, Cu, Zn, Ga, Ge, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, 
Cd, Sn, Ba, Ce, Eu, W, Re, Os, Tr, Pt, Hg, Tl, Pb, Bi and In. The 
polyvalent metal compound is preferably selected from mono-salts or metal 
complexes. The metal complex may be a 6-coordinated, 5-coordinated 
4-coordinated or 2-coordinated complex and more preferably octahedral 
6-coordinated complex or planar 4-coordinated complex. The metal complex 
may be a mononucleus complex or polynucleus complex. Examples of ligands 
constituting the complex include CN.sup.-, CO, NO.sub.2.sup.-, 
1,10-phenanthroline, 2,2'-bipyridine, SO.sub.3.sup.-, ethylenediamine, 
NH.sub.3, pyridine, H.sub.2 O, NCS.sup.-, NCO.sup.-, N.sub.3.sup.-, 
SO.sub.4.sup.-, OH.sup.-, N.sub.3.sup.-, S.sub.2.sup.-, F.sup.-, Cl.sup.-, 
Br.sup.- and I.sup.-. Of the polyvalent metal compounds preferred are 
K.sub.4 Fe(CN).sub.6, K.sub.3 Fe(CN).sub.6, Pb(NO.sub.3).sub.2, K.sub.2 
IrCl.sub.6, K.sub.3 IrCl.sub.6, K.sub.2 TrBr.sub.6, InCL.sub.3. 
The polyvalent metal compound is contained preferably in an amount of 
10.sup.-9 to 10.sup.-4 and more preferably 10.sup.-9 to 10.sup.-5 mol per 
mol of silver halide. Distribution of the polyvalent metal compound within 
the tabular grain can be determined, for example, by fractionally 
dissolving the grain from the surface and measuring the content of each 
fraction according to the following manner. 
Prior to determination of the content of the polyvalent compound, a silver 
halide tabular grain emulsion is subjected to the following pre-treatment. 
To about 30 ml of the emulsion is added 50 ml of a 0.2% actinase aqueous 
solution and stirred continuously at 40.degree. C. for 30 min. to perform 
degradation of the gelatin. This procedure is repeated five times. After 
centrifuging, washing is repeated five times with 50 ml of methanol, two 
times with 50 ml of 1N nitric acid solution and five times with ultra-pure 
water, and after centrifuging, only tabular grains are separated. A 
surface portion of the resulting tabular grains is dissolved with aqueous 
ammonia or pH-adjusted ammonia (in which the concentration of ammonia or 
the pH is varied according to the kind of silver halide and the 
dissolution amount). Of the tabular grains, for example, the outermost 
surface portion of silver bromide grains can be dissolved to an extent of 
about 3% from the surface, using 20 ml of 10% aqueous ammonia per 2 g of 
silver bromide grains. The amount of dissolved silver bromide can be 
determined in the following manner. After dissolving, the solution is 
subjected to centrifuging to separate any remaining silver bromide grains 
and the amount of silver contained in the resulting supernatant can be 
determined with a high frequency induction plasma mass spectrometer 
(ICP-MS), a high frequency induction plasma emission spectral analyzer 
(ICP-AES) or an atomic absorption spectrometer. From the difference in the 
content of the polyvalent metal compound between the surface-dissolved 
silver bromide grains and the undissolved silver bromide grains, the 
amount of the polyvalent metal compound present in about the grain surface 
of 3% (i.e., it means that silver halide corresponding to about 3% of the 
total silver amount is dissolved from the surface). 
To determine the content of the polyvalent metal compound, after dissolving 
in an aqueous ammonium thiosulfate solution, aqueous sodium thiosulfate 
solution or aqueous potassium cyanide solution and the resulting solution, 
quantitative analysis is performed by an ICP-MS method, an ICP-AES method 
or an atomic absorption method. In the case when using potassium cyanide 
as a solvent and ICP-MS (FISON produced by Elemental Analysis Corp.) as an 
analyzer, for example, about 40 mg of tabular silver halide grains is 
dissolved in 5 ml of an aqueous 0.2N potassium cyanide solution, a 
solution of an internal standard element Cs is added thereto in an amount 
10 ppb and a measuring sample is prepared further by adding ultra-pure 
water to make a total volume 100 ml. Using a calibration curve with 
respect to a polyvalent metal compound which has been prepared by the use 
of tabular silver halide grains free from the polyvalent metal compound, 
the content of the polyvalent metal compound contained in a sample is 
determined by the ICP-MS method. In this case, a measuring sample is 
diluted by 100 times with ultra-pure water and the silver content thereof 
is measured with the ICP-AES method or atomic absorption method. After 
dissolving the grain surface, the tabular grains is washed with ultra-pure 
water and the content of the polyvalent metal compound in the internal 
direction of the grain can be determined by repeating the dissolution of 
the grain surface in the same manner as described above. 
The surface of the tabular grains in the invention (i.e. grain surface) is 
referred to as the portion corresponding to not less than 10% of the total 
silver amount of the grains, as the dissolved silver amount when the 
tabular grains is subjected to the surface dissolution treatment in such a 
manner as above-described. 
The method for adding the polyvalent metal compound used in the invention 
is not specifically limited. Thus, the metal compound is dissolved in 
water of an organic solvent such as methanol or acetone and added in the 
form of a solution, or is directly added in the form of a solid fine 
particle dispersion. 
Tabular silver halide grains used in the invention are prepared preferably 
by growing seed grains. Concretely, to a reaction vessel having an aqueous 
solution containing a protective colloid and seed grains are supplied 
silver ions, halide ions and optionally silver halide fine grains to grow 
the seed grains. The seed grains can be prepared by any method known in 
the photographic art, such as a single-jet addition or double-jet 
addition. The halide composition of the seed grains is optional and any of 
silver bromide, silver chloride, silver iodobromide, silver iodochloride, 
silver chlorobromide and silver iodochlorobromide can be employed. Of 
these, silver bromide and silver iodobromide are preferable and silver 
iodobromide is more preferable. Silver iodobromide contains preferably 1 
to 10 mol % iodide. 
In cases where the tabular grains are prepared by growing seed grains, the 
central portion of the grain may have a different halide composition from 
that of the core. The seed grains preferably account for not more than 
50%, and more preferably not more than 10% of the total silver halide, 
based on silver. 
Tabular silver halide grains used in the invention are each comprised of a 
core and a shell which covers the core. The shell may be comprised of one 
or more layers. The halide composition of the core and shell is optional. 
The proportion of the core is preferably 1 to 60% and more preferably 4 to 
40%, based on silver of the grain. In cases where the core is different in 
the iodide content from the shell, it is preferable to have a sharp 
boundary between the core and the shell with respect to the iodide 
content. It is also preferable that an intermediate layer be present 
between the core and the shell. The proportion of the intermediate layer 
is preferably 0.1 to 20% and more preferably 0.5 to 10%, based on silver, 
of the grain. The iodide content of the intermediate layer preferably is 
higher, by 2 mol % or more, than that of the shell. 
Distribution of the iodide within core/shell type silver halide grains can 
be determined by a variety of physical measuring methods, such as 
measurement of luminescence at low temperature and X-ray diffractometry as 
described in Abstracts of Annual Meeting of the Society of Photographic 
Science and Technology of Japan (1981). 
Tabular silver halide grains used in the invention can be prepared by a 
variety of methods known in the art, such as single-jet addition, 
controlled double-jet addition and controlled triple-jet addition. To 
prepare highly monodispersed grains, it is important to control the pAg of 
the liquid phase in which silver halide grains are formed, in proportion 
to the growing rate of silver halide grains. The pAg is to be within the 
range of 7.0 to 11.0, preferably 7.5 to 10.5 and more preferably 8.0 to 
10.0. The flow rate is referred to techniques described in JP-A 54-48521 
and 58-49938. 
The tabular grains used in the invention can be prepared in the presence of 
known silver halide solvents, such as ammonia, thioethers and thioureas. 
The tabular grains may be surface latent image forming grains or internal 
latent image forming grains. 
The tabular grains can be prepared in the presence of a dispersing medium, 
i.e. in a solution containing a dispersing medium. The solution containing 
a dispersing medium is referred to as an aqueous solution in which a 
protective colloid is formed with a material such as gelatins or other 
hydrophilic colloids (material usable as a binder), and is preferably an 
aqueous solution containing gelatin as a protective colloid. As gelatin 
usable in the invention, any type of gelatin can be employed, including 
lime-processed gelatin and acid-processed gelatin. Details of the 
preparation method of gelatin are referred to A. Veis, "The Macromolecular 
Chemistry of Gelatin" (Academic Press, 1964). Examples of hydrophilic 
colloids usable as a protective colloid, other than gelatin, include 
gelatin derivatives, a graft polymer of gelatin and another polymer, 
proteins such as albumin and casein, cellulose derivatives such as 
hydroxyethyl cellulose, carboxymethyl cellulose and cellulose sulfuric 
acid ester, sodium alginic acid, saccharine derivatives such as starch 
derivatives, and synthetic hydrophilic polymer materials such as polyvinyl 
alcohol, partial acetal of polyvinyl alcohol, poly-N-vinyl pyrrolidone, 
polyacrylic acid, polymethacrylic acid, polyacrylamide, polyvinyl 
imidazole, polyvinyl pyrazole, and their respective copolymer. In the case 
of gelatin, there is preferably employed gelatin having a jelly strength 
of 200 or more, as defined in PAGI method. 
A tabular grain emulsion used in the invention, after completing growth of 
the tabular grains, can be desalted to remove soluble salts. Desalting can 
be performed any time during the course of growing the grains, as 
described in JP-A 60-138538. Desalting is conducted based on the method 
described in Research Disclosure (hereinafter, denoted as "RD") 17643, 
section II. More concretely, to remove soluble salts from an emulsion 
after completion of grain formation or physical ripening, there may be 
employed a noodle washing method in which gelatin is gelled, and 
flocculation method in which inorganic salts, anionic surfactants, anionic 
polymers (e.g. polystyrene sulfonic acid), gelatin derivatives (e.g. 
acylated gelatin, carbamoyl gelatin) are employed. 
The iodide content of each of silver halide grains (including tabular 
grains), and the average iodide content can be determined by the EPMA 
method (Electron Probe Micro Analyzer method). Thus, a sample can be 
prepared, in which silver halide grains are dispersed so as not to be in 
contact with each other, and an electron beam is irradiated onto each 
grain. Elemental analysis of a minute portion can be made through analysis 
of X-rays produced by electron beam excitation. According to this method, 
the halide composition of each grain can be determined by measuring 
characteristic X-ray strengths of silver and iodide, radiating from each 
grain. The average iodide content can be determined by obtaining iodide 
contents of at least 50 grains through the EPMA method. In the tabular 
grains used in the invention, it is preferred that the iodide distribution 
among grains be uniform. When the iodide distribution among the grains is 
measured by the EPMA method, the relative standard deviation is preferably 
not more than 30%, and more preferably not more than 20%. 
Tabular grains used in the invention can be chemically sensitized by any of 
the several conventional methods. Thus, sulfur sensitization, selenium 
sensitization or noble metal sensitization with gold or other noble metals 
may be employed singly or in combination thereof. 
The tabular grains can also be optically sensitized to a desired wavelength 
region using a sensitizing dye known in the photographic art. The 
sensitizing dye can be employed singly or in combination thereof. There 
may be incorporated, with the sensitizing dye, a dye having no spectral 
sensitizing ability or a supersensitizer which does not substantially 
absorb visible light and enhances sensitization of the dye. 
An antifoggant and stabilizer can be added into the tabular grain emulsion. 
Gelatin is advantageously employed as a binder. An emulsion layer or other 
hydrophilic colloid layers can be hardened with hardeners. A plasticizer 
or a dispersion of a water-soluble or water-insoluble polymer (so-called 
latex) can be incorporated. 
In a silver halide emulsion layer of a photographic material, a coupler can 
be employed. There can also be employed a competing coupler having an 
effect of color correction and a compound which, upon coupling reaction 
with an oxidation product of a developing agent, is capable of releasing a 
photographically useful fragment, such as a developing accelerator, a 
developing agent, a silver halide solvent, a toning agent, hardener, a 
fogging agent, a chemical sensitizer, a spectral sensitizer and a 
desensitizer. 
A filter layer, anti-halation layer or anti-irradiation layer can be 
provided in the photographic material relating to the invention. In these 
layers and/or an emulsion layer, a dye which is leachable from a processed 
photographic material or bleachable during processing, can be 
incorporated. Furthermore, a matting agent, lubricant, image stabilizer, 
formalin scavenger, UV absorbent, brightening agent, surfactant, 
development accelerator or development retarder is also incorporated into 
the photographic material. Employed may be, as a support, 
polyethylene-laminated paper, polyethylene terephthalate film, baryta 
paper or cellulose triacetate film.

EXAMPLES 
Embodiments of the present invention will be further explained, based on 
examples but the invention is not limited to these examples. 
Example 1 
Preparation of seed grain emulsion T-1 
According to the following procedure, there was prepared a seed grain 
emulsion comprised of twin crystal grains having two parallel twin planes. 
______________________________________ 
Solution A 
Ossein gelatin 24.2 g 
Potassium bromide 10.75 g 
Nitric acid (1.2N) 118.6 ml 
HO(CH.sub.2 CH.sub.2 O).sub.m (CH(CH.sub.3)HCH.sub.2 O).sub.19.8 (CH.sub.2 
CH.sub.2 O).sub.n H 6.78 ml 
(m + n = 9.77) 10 wt. % methanol solution 
Distilled water to make 9686 ml 
Solution B 
Silver nitrate 1200 g 
Distilled water to make 2826 ml 
Solution C 
Potassium bromide 823.8 g 
Potassium iodide 23.46 g 
Distilled water to make 2826 ml 
Solution D 
Ossein gelatin 120.9 g 
Distilled water to make 2130 ml 
Solution E 
Potassium bromide 76.48 g 
Distilled water to make 376 ml 
Solution F 
Potassium hydroxide 10.06 g 
Distilled water to make 340 ml 
______________________________________ 
To solution A at 35.degree. C. with vigorously stirring were added 464 ml 
of solution B and 464 ml of solution C by the double jet method over a 
period of 2 min. to form nucleus grains, while the pAg was maintained at 
10.02 by using solution E. Then, the temperature was raised to 60.degree. 
C. taking 66 min. At the time when the temperature reached 55.degree. C., 
solution D was added taking 7 min. At the time when the temperature 
reached 60.degree. C., solution F was added taking 1 min. and 
subsequently, 2362 ml of solution B and 2362 ml of solution C wee added 
over a period of 43 min. The pAg was maintained at 9.17 immediately after 
raising the temperature. After completing addition of solutions B and C, 
the emulsion was desalted according to the conventional manner. To the 
desalted emulsion was added an aqueous 10 wt. % gelatin solution, stirring 
was further continued at 55k C. for 30 min. and distilled water was added 
to prepare an emulsion of 5,360 g. Electron microscopic observation 
revealed that the resulting emulsion was comprised of tabular grains 
having two parallel twin planes. It was also proved that the resulting 
seed grains had an average grain diameter of 0.445 .mu.m and an aspect 
ratio of 6.0 at the time of 50% of the projected area, and grains having 
two parallel twin planes accounted for 75% of the total grain projected 
area. 
Preparation of seed grain emulsion T-2 
A twin crystal seed grain emulsion T-2 was prepared in the same manner as 
emulsion T-1, except that ossein gelatin used in solution A was replaced 
by a low molecular weight gelatin having a molecular weight of 15,000. It 
was proved that the resulting seed grains had an average grain diameter of 
0.445 .mu.m and an aspect ratio of 6.0 at the time of 50% of the projected 
area, and grains having two parallel twin planes accounted for 80% of the 
total grain projected area. 
Preparation of seed grain emulsion T-3 
A twin crystal seed grain emulsion T-3 was prepared in the same manner as 
emulsion T-2, except that the time for raising the temperature to 
60.degree. C. after nucleation was changed to 30 min. It was proved that 
the resulting seed grains had an average grain diameter of 0.445 .mu.m and 
an aspect ratio of 6.0 at the time of 50% of the projected area, and 
grains having two parallel twin planes accounted for 90% of the total 
grain projected area. 
Preparation of emulsion EM-1 
Using the following six kinds of solutions, emulsion EM-1 was prepared. 
______________________________________ 
Solution A 
Ossein gelatin 163.4 g 
HO(CH.sub.2 CH.sub.2 O).sub.m (CH(CH.sub.3)HCH.sub.2 O).sub.19.8 (CH.sub.2 
CH.sub.2 O).sub.n H 2.50 ml 
(m + n = 9.77) 10 wt. % methanol solution 
Seed grain emulsion T-3 674.5 g 
Potassium bromide 3.0 g 
Distilled water to make 3500 ml 
Solution B 
Silver nitrate 2581.7 g 
Distilled water to make 4342 ml 
Solution C 
Potassium bromide 1828.3 g 
Distilled water to make 4390 ml 
Solution D 
Potassium bromide aqueous solution (1.75N) 
Solution E 
Acetic acid aqueous solution (56 wt. %) 
Solution F 
Fine grain emulsion comprised of 3 wt. % gelatin 
2793 g 
and silver iodide (av. size, 0.05 .mu.m) 
______________________________________ 
The above fine grain emulsion was prepared in the following manner. To 5000 
ml of a 6.0 wt. % gelatin solution containing 0.06 mol of potassium 
iodide, an aqueous solution containing 7.06 mol of silver nitrate and an 
aqueous solution containing 7.06 mol of potassium iodide, 2000 ml of each 
were added over a period of 10 min., while the pH was maintained at 2.0 
using nitric acid and the temperature was maintained at 40.degree. C. 
After completion of grain formation, the pH was adjusted to 6.0 using a 
sodium carbonate aqueous solution. The finished weight of the emulsion was 
12.53 kg. 
To solution A maintained at 75.degree. C. with stirring were added 
solutions B, C and F by triple-jet addition or single-jet addition 
according to the conditions as shown in Table 1 to grow seed crystal 
grains to obtain a silver halide tabular grain emulsion. Flow rates of 
solutions B, C and F at the triple-jet addition and a flow rate of 
solution F at the single-jet addition were each acceleratedly varied so as 
to meet the critical growth rate to prevent production of new nucleus 
grain and widening of grain size distribution due to Ostwald ripening. The 
pAg and pH were each controlled using solutions D and E, during the course 
of growing grains. After completing grain growth, the emulsion was 
desalted according to the method described in JP-A 5-72658. Then, gelatin 
was further added thereto to redisperse the emulsion and the pH and pAg 
were adjusted to 5.80 and 8.06, respectively. 
TABLE 1 
______________________________________ 
Mixing 
time Flow rate (ml/min) Temperature 
(min) B C F pH pAg (.degree. C.) 
______________________________________ 
0.00 7.8 7.5 3.8 4.0 8.6 75 
23.2 9.9 9.5 4.8 4.0 8.6 75 
45.5 12.3 11.8 6.0 4.0 8.6 75 
85.7 15.1 14.5 7.4 4.0 8.6 75 
102.1 16.1 15.5 7.9 4.0 8.6 75 
120.5 17.2 16.5 8.4 4.0 8.6 75 
141.2 18.4 17.6 9.0 4.0 8.6 75 
164.3 19.6 18.7 9.6 4.0 8.6 75 
190.2 22.8 32.7 10.2 4.0 8.6 75 
190.3 0.0 0.0 266.0 4.0 8.6 75 
192.3 0.0 0.0 266.0 4.0 9.6 75 
192.4 9.6 12.0 3.8 4.0 9.6 75 
202.7 76.7 82.1 30.2 4.0 9.6 75 
204.7 83.0 89.0 31.7 4.0 9.6 75 
204.8 83.4 89.2 13.6 4.0 9.6 75 
213.0 87.1 93.2 14.2 4.0 9.6 75 
______________________________________ 
From electron micrographs of the resulting emulsion grains, 79.2% of the 
resulting emulsion was accounted for by tabular grains having an average 
grain diameter of 1.348 .mu.m (mean value of circle-equivalent diameters), 
an aspect ratio of 5.0 or more, and a variation coefficient (V.C.) of 
grain size of 12.0%. It was further proved that the tabular grains 
exhibited characteristic values with respect of variation coefficients of 
the spacing and the grain thickness, and the iodide content, as shown in 
Table 2. Furthermore, transmission electron microscopic observation 
revealed that at least 80% of the total grain projected area was accounted 
for by grains each having 10 or more dislocation lines in the fringe 
portion. 
Preparation of emulsion EM-2 
An emulsion EM-2 was prepared in the same manner as EM-1, except that the 
seed grain emulsion (T-3) was replaced by T-1. 
Preparation of emulsion EM-3 
An emulsion EM-3 was prepared in the same manner as EM-1, except that after 
the mixing time of 192.3 min., the pAg was changed to 10.5 and the flow 
rate of each solution was acceleratedly varied so as to meet the growing 
rate of silver halide grains. 
Preparation of emulsion EM-4 
An emulsion EM-4 was prepared in the same manner as EM-1, except that 
single-jet addition of solution of solution F was interrupted over a 
period of 2 min. after the mixing time of 190.3 min. As a result of 
observation of the resulting emulsion grains by a transmission electron 
microscope, there was found no grains having dislocation line. 
Preparation of emulsion EM-5 
An emulsion EM-5 was prepared in the same manner as EM-4, except that the 
pAg at the time of forming a core portion and the pAg at the time of 
forming a shell portion were changed to 7.9 and 9.1, respectively, and the 
flow rate of each solution was acceleratedly varied so as to meet the 
growing rate of silver halide grains. 
Preparation of emulsion EM-6 
An emulsion EM-6 was prepared in the same manner as EM-4, except that the 
seed grain emulsion was replaced by T-2. 
Preparation of emulsion EM-7 
An emulsion EM-7 was prepared in the same manner as EM-4, except that the 
flow rate of each solution was proportionally lowered and the mixing time 
was extended to 1.5 times. 
Preparation of emulsion EM-8 
An emulsion EM-8 was prepared in the same manner as EM-4, except that the 
flow rate of each solution was varied. 
Preparation of emulsion EM-9 
An emulsion EM-9 was prepared in the same manner as EM-4, except that when 
an average diameter of growing grains reached 1.281 .mu.m, solution G 
described below was instantaneously added, while addition of solutions B, 
C and F was continued. 
______________________________________ 
Solution G 
______________________________________ 
K.sub.2 IrCl.sub.6 0.829 mg 
Nitric acid (specific gravity of 1.38) 
0.50 ml 
25 wt. % NaCl aqueous solution to make 
50 ml 
______________________________________ 
Preparation of emulsion EM-10 
An emulsion EM-10 was prepared in the same manner as EM-9, except that when 
an average diameter of growing grains reached 1.069 .mu.m, solution G was 
added. 
Preparation of emulsion EM-11 
An emulsion EM-11 was prepared in the same manner as EM-9, except that the 
seed grain emulsion was replaced by T-1. 
Preparation of emulsion EM-12 
An emulsion EM-12 was prepared in the same manner as EM-1, except that 
solution G was instantaneously added, while addition of solutions B, C and 
F was continued. 
Characteristics of prepared emulsions are shown in Table 2. 
TABLE 2 
__________________________________________________________________________ 
V.C. Iodide content 
of (mol %) 
Seed 
Tabular 
grain Inter- 
Grain Dislo- 
Ir content Ag 
Emul- 
emul- 
grains 
size 
x y nal 
sur- 
Over- 
cation 
(mol/mol Agx) 
con- 
Re- 
sion sion 
(%) (%) 
(%) (%) 
y/x layer 
face 
all 
line Overall 
Surface 
tent 
mark 
__________________________________________________________________________ 
EM-1 T-3 
79.2 12.0 
16.8 
19.3 
1.15 
35.5 
15.43 
9.06 
Yes -- -- -- Inv. 
EM-2 T-1 
64.1 22.1 
8.9 
28.9 
3.25 
35.5 
13.29 
9.06 
Yes -- -- -- Comp. 
EM-3 T-3 
93.6 14.3 
12.2 
15.1 
1.24 
35.5 
15.98 
9.06 
Yes -- -- -- Inv. 
EM-4 T-3 
80.5 10.4 
14.2 
16.5 
1.16 
13.0 
9.66 
8.71 
No -- -- -- Inv. 
EM-5 T-3 
37.4 8.6 
22.3 
27.4 
1.23 
13.0 
8.84 
8.71 
No -- -- -- Comp. 
EM-6 T-2 
66.9 21.7 
10.5 
33.7 
3.21 
13.0 
8.82 
8.71 
No -- -- -- Comp. 
EM-7 T-3 
64.7 28.2 
13.1 
24.5 
1.87 
13.0 
8.79 
8.71 
No -- -- -- Comp. 
EM-8 T-3 
79.6 11.9 
15.2 
17.0 
1.12 
7.0 
7.45 
7.93 
No -- -- -- Comp. 
EM-9 T-3 
82.3 11.5 
15.7 
17.9 
1.14 
13.0 
10.08 
8.71 
No 4.85 .times. 10.sup.-8 
8.97 .times. 10.sup.-9 
3.3 
Inv. 
EM-10 
T-3 
80.2 11.6 
16.0 
18.2 
1.14 
13.0 
9.92 
8.71 
No 5.01 .times. 10.sup.-8 
1.26 .times. 10.sup.-9 
3.1 
Inv. 
EM-11 
T-1 
71.5 24.4 
10.6 
34.9 
3.29 
13.0 
9.86 
8.71 
No 4.83 .times. 10.sup.-8 
6.44 .times. 10.sup.-9 
3.2 
Comp. 
EM-12 
T-3 
83.1 12.1 
13.1 
14.3 
1.09 
35.5 
14.73 
9.06 
Yes 4.96 .times. 10.sup.-8 
7.15 .times. 10.sup.-9 
3.4 
Inv. 
__________________________________________________________________________ 
In the Table, the percentage of tabular grains indicates those having an 
aspect ratio of 5 or more, based on the grain projected area; x represent 
a variation coefficient of a spacing between at least two twin planes; and 
y represents a variation coefficient of grain thickness. The spacing 
between twin planes and grain thickness were determined in transmission 
electron microscopy at a acceleration voltage of 200 kV and a temperature 
of -120.degree. C. (JEM-2000FX, produced by Nihon Denshi Co.) 
The amount of iridium contained in the surface portion was determined in 
the following manner. The overall iridium content of grains (X) and the 
iridium content of the grains which have been subjected to surface 
dissolving treatment afore-mentioned (Y) were each measured. Difference of 
X-Y was defined as an iridium content in the surface portion. The silver 
content (%) of the surface portion is also shown in the Table. 
Example 2 
Preparation of photographic material 
Emulsions EM-1 through EM-12 were each subjected to gold-sulfur 
sensitization and using these emulsions, the following layers having the 
composition described below were coated on a cellulose triacetate film 
support in this order from the support to prepare a multi-layered color 
photographic material. 
A color photographic material 101 was as shown below, wherein the addition 
amount was expressed in g per m.sup.2, unless otherwise noted. The coating 
amount of silver halide or colloidal silver was converted to silver. With 
respect to a sensitizing dye, it was expressed in mol per mol of silver 
halide contained in the same layer. 
______________________________________ 
1st layer; Antihalation layer 
Black colloidal silver 0.16 
UV absorbent (UV-1) 0.20 
High boiling solvent (OIL-1) 
0.16 
Gelatin 1.60 
2nd layer; Interlayer 
Compound (SC-1) 0.14 
High boiling solvent (OIL-2) 
0.17 
Gelatin 0.80 
3rd layer; Low speed red-sensitive layer 
Silver iodobromide emulsion A 
0.15 
Silver iodobromide emulsion B 
0.35 
Sensitizing dye (SD-1) 2.0 .times. 10.sup.-4 
Sensitizing dye (SD-2) 1.4 .times. 10.sup.-4 
Sensitizing dye (SD-3) 1.4 .times. 10.sup.-5 
Sensitizing dye (SD-4) 0.7 .times. 10.sup.-4 
Cyan coupler (C-1) 0.53 
Colored cyan coupler (CC-1) 
0.04 
DIR compound (D-1) 0.025 
High boiling solvent (OIL-3) 
0.48 
Gelatin 1.09 
4th layer; Medium speed red-sensitive layer 
Silver iodobromide emulsion B 
0.30 
Silver iodobromide emulsion C 
0.34 
Sensitizing dye (SD-1) 1.7 .times. 10.sup.-4 
Sensitizing dye (SD-2) 0.86 .times. 10.sup.-4 
Sensitizing dye (SD-3) 1.15 .times. 10.sup.-5 
Sensitizing dye (SD-4) 0.86 .times. 10.sup.-4 
Cyan coupler (C-1) 0.33 
Colored cyan coupler (CC-1) 
0.013 
DIR compound (D-1) 0.02 
High boiling solvent (OIL-1) 
0.16 
Gelatin 0.79 
5th layer; High speed red-sensitive layer 
Silver iodobromide emulsion EM-1 
0.95 
Sensitizing dye (SD-1) 1.0 .times. 10.sup.-4 
Sensitizing dye (SD-2) 1.0 .times. 10.sup.-4 
Sensitizing dye (SD-3) 1.2 .times. 10.sup.-5 
Cyan coupler (C-2) 0.14 
Colored cyan coupler (CC-1) 
0.016 
High boiling solvent (OIL-1) 
0.16 
Gelatin 0.79 
6th layer; Interlayer 
Compound (SC-1) 0.09 
High boiling solvent (OIL-2) 
0.11 
Gelatin 0.80 
7th layer; Low speed green-sensitive layer 
Silver iodobromide emulsion A 
0.12 
Silver iodobromide emulsion B 
0.38 
Sensitizing dye (SD-4) 4.6 .times. 10.sup.-5 
Sensitizing dye (SD-5) 4.1 .times. 10.sup.-4 
Magenta coupler (M-1) 0.14 
Magenta coupler (M-2) 0.14 
Colored magenta coupler (CM-1) 
0.06 
High boiling solvent (OIL-4) 
0.34 
Gelatin 0.70 
8th layer; Interlayer 
Gelatin 0.41 
9th layer; Medium speed green-sensitive layer 
Silver iodobromide emulsion B 
0.30 
Silver iodobromide emulsion C 
0.34 
Sensitizing dye (SD-6) 1.2 .times. 10.sup.-4 
Sensitizing dye (SD-7) 1.2 .times. 10.sup.-4 
Sensitizing dye (SD-8) 1.2 .times. 10.sup.-4 
Magenta coupler (M-1) 0.04 
Magenta coupler (M-2) 0.04 
Colored magenta coupler (CM-1) 
0.017 
DIR compound (D-2) 0.025 
DIR compound (D-3) 0.002 
High boiling solvent (OIL-5) 
0.12 
Gelatin 0.50 
10th layer; High speed green-sensitive layer 
Silver iodobromide emulsion D 
0.95 
Sensitizing dye (SD-6) 7.1 .times. 10.sup.-5 
Sensitizing dye (SD-7) 7.1 .times. 10.sup.-5 
Sensitizing dye (SD-8) 7.1 .times. 10.sup.-5 
Magenta coupler (M-1) 0.09 
Colored magenta coupler (CM-2) 
0.011 
High boiling solvent (OIL-4) 
0.11 
Gelatin 0.79 
11th layer; Yellow filter layer 
Yellow colloidal silver 0.08 
Compound (SC-1) 0.15 
High boiling solvent (OIL-2) 
0.19 
Gelatin 1.10 
12th layer; Low speed blue-sensitive layer 
Silver iodobromide emulsion A 
0.12 
Silver iodobromide emulsion B 
0.24 
Silver iodobromide emulsion C 
0.12 
Sensitizing dye (SD-9) 6.3 .times. 10.sup.-5 
Sensitizing dye (SD-10) 1.0 .times. 10.sup.-5 
Yellow coupler (Y-1) 0.50 
Yellow coupler (Y-2) 0.50 
DIR compound (D-4) 0.04 
DIR compound (D-5) 0.02 
High boiling solvent (OIL-2) 
0.42 
Gelatin 1.40 
13th layer; High speed blue-sensitive layer 
Silver iodobromide emulsion C 
0.15 
Silver iodobromide emulsion E 
0.80 
Sensitizing dye (SD-9) 8.0 .times. 10.sup.-5 
Sensitizing dye (SD-11) 3.1 .times. 10.sup.-5 
Yellow coupler (Y-1) 0.12 
DIR compound (D-6) 0.02 
High boiling solvent (OIL-2) 
0.05 
Gelatin 0.79 
14th layer; First protective layer 
Silver iodobromide emulsion (Av. grain 
0.40 
size of 0.08 .mu.m, 1 mol % iodide) 
UV absorbent (UV-1) 0.065 
High boiling solvent (OIL-1) 
0.07 
High boiling solvent (OIL-3) 
0.07 
Gelatin 0.65 
15th layer; Second protective layer 
Alkali-soluble matting agent (PM-1, Av. 2 .mu.m) 
0.15 
Polymethylmethacrylate (Av. 3 .mu.m) 
0.04 
Slipping agent (WAX-1) 0.04 
Gelatin 0.55 
______________________________________ 
In addition to the above composition were added coating aids (SU-1 and 2), 
viscosity-adjusting agent (V-1), Hardener (H-1 and 2), stabilizer (ST-1), 
fog restrainer (AF-1), dye (AI-1 and 2), AF-2 comprising two kinds of 
weight-averaged molecular weights of 10,000 and 1.100,000 and antimold 
(DI-1). 
##STR1## 
Emulsions A, B, C, D and E are summarized in Table 3. Each emulsion was 
subjected to gold-sulfur sensitization. In the Table, diameter/thickness 
represents the ratio of the grain diameter to the grain thickness of each 
emulsion. 
TABLE 3 
______________________________________ 
Av. iodide 
Av. grain 
content diameter Crystal 
diameter/ 
Emulsion (mol %) (.mu.m) habit thickness 
______________________________________ 
A 4.0 0.41 Regular 
1 
B 6.0 0.57 Regular 
1 
C 6.0 0.75 Regular 
1 
D 6.0 1.16 Tabular 
4 
E 6.0 1.30 Tabular 
4 
______________________________________ 
Photographic material samples 102 to 112 were prepared in the same manner 
as photographic material 101, except that emulsion EM-1 was replaced by 
EM-2 to EM-12, respectively. Samples were each subjected to wedge-exposure 
(1/100") and color processing. 
Processing steps are as follows: 
______________________________________ 
1. Color developing 
3 min. 15 sec. 
38.0 .+-. 0.1.degree. C. 
2. Bleach 6 min. 30 sec. 
38.0 .+-. 3.0.degree. C. 
3. Washing 3 min. 15 sec. 
24-41.degree. C. 
4. Fixing 6 min. 30 sec. 
38.0 .+-. 3.0.degree. C. 
5. Washing 3 min. 15 sec. 
24-41.degree. C. 
6. Stabilizing 3 min. 15 sec. 
38.0 .+-. 3.0.degree. C. 
7. Drying 50.degree. C. or less 
______________________________________ 
Composition of a processing solution used in each step is as follows. 
______________________________________ 
Color developing solution 
4-Amino-3-methyl-N-ethyl-N-(.beta.-hydroxy 
4.75 g 
ethyl)aniline sulfate 
Sodium sulfite anhydride 4.25 g 
Hydroxylamine 1/2 sulfate 2.0 g 
Potassium carbonate anhydride 
37.5 g 
Sodium bromide 1.3 g 
Trisodium nitrilotriacetate (monohydrate) 
2.5 g 
Potassium hydroxide 1.0 g 
Water to make 1 liter 
The pH was adjusted to 10.1. 
Bleaching solution 
Ammonium ferric ethylenediaminetetraacetate 
100.0 g 
Diammonium ethylenediaminetetraacetate 
10.0 g 
Ammonium bromide 150.0 g 
Glacial acetic acid 10.0 g 
Water to make 1 liter 
The pH was adjusted to 6.0 using ammonia water. 
Fixing solution 
Ammonium thiosulfate 175.0 g 
Sodium sulfite anhydride 8.5 g 
Sodium metasulfite 2.3 g 
Water to make 1 liter 
The pH was adjusted to 6.0 with acetic acid. 
Stabilizing solution 
Formalin (37% aqueous solution) 
1.5 ml 
Koniducks (product by Konica Corp.) 
7.5 ml 
Water to make 1 liter 
______________________________________ 
Processed photographic materials were evaluated with respect to 
photographic characteristics of the red-sensitive layer. 
Sensitivity 
Sensitivity was shown as a relative value of reciprocal of exposure giving 
a magenta density of Dmin (minimum density)+0.15, based on that of Sample 
101 being 100. The highere the value, the higher the sensitivity. 
Graininess 
Graininess was shown as a relative value of a standard deviation of density 
variation (RMS value) at a density of Dmin+0.50 which was measured with a 
microdensitometer, based on that of Sample 101 being 100. The lower the 
RMS value, the better the graininess. 
Pressure characteristics 
After contacting with a needle having a 0.025 mm curvature radius of the 
point, loaded with a load of 5 g and moving at a constant speed using a 
scratch tester (produced by Shinto Kagaku) at 23.degree. C and 55% RH, 
photographic material samples were each exposed and processed. The density 
variation, at a density of Dmin+0.40, of the loaded portion (.DELTA.D) was 
measured. .DELTA.D, which indicates a measure of pressure resistance, is 
represented as a relative value, based on that of Sample 101 being 100. 
The lower the value of .DELTA.D, the better the pressure resistance. 
High intensity reciprocity failure characteristics (HIRF) 
After being subjected to exposure at 1/10000 sec., photographic material 
samples were processed within 1 min of the exposure. The sensitivity of 
high intensity exposure was shown as a relative value, based on the 
above-described relative sensitivity of Sample 101 being 100. The lower 
the difference between the relative sensitivity and the high intensity 
exposure sensitivity , the more improved the high intensity reciprocity 
failure. 
Results thereof are shown in Table 4. 
TABLE 4 
______________________________________ 
Pressure 
Sample 
Emulsion Sensitivity 
Graininess 
(.DELTA.D) 
HIRF Remark 
______________________________________ 
101 EM-1 100 100 100 98 Inv. 
102 EM-2 81 123 119 63 Comp. 
103 EM-3 109 98 101 104 Inv. 
104 EM-4 95 102 105 90 Inv. 
105 EM-5 52 96 106 54 Comp. 
106 EM-6 68 134 115 51 Comp. 
107 EM-7 71 137 120 62 Comp. 
108 EM-8 74 125 131 67 Comp. 
109 EM-9 103 103 104 103 Inv. 
110 EM-10 102 100 101 98 Inv. 
111 EM-11 82 121 123 67 Comp. 
112 EM-12 118 96 97 118 Inv. 
______________________________________ 
As can be seen from Table 4, it is proved that inventive samples exhibited 
higher sensitivity, superior graininess, and improved pressure resistance 
and high intensity reciprocity failure characteristics. Specifically, 
Sample 112, which was one of the best mode of the invention, exhibited 
excellent photographic performance.