US3843369A

US3843369A - Multi-layer color photographic light-sensitive materials

Info

Publication number: US3843369A
Application number: US00259109A
Authority: US
Inventors: A Kumai; T Usami
Original assignee: Fuji Photo Film Co Ltd
Current assignee: Fujifilm Holdings Corp
Priority date: 1969-04-17
Filing date: 1972-06-02
Publication date: 1974-10-22
Anticipated expiration: 1991-10-22

Abstract

1. IN A GELATINO-SILVER HALIDE COLOR PHOTOGRAPHIC MULTILAYER LIGHT-SENSITIVE MATERIAL COMPRISING A SUPPORT HAVING THEREON A RED-SENSITIVE ELEMENT, A GREEN-SENSITIVE ELEMENT AND A BLUE-SENSITIVE ELEMENT, EACH OF SAID ELEMENTS CONTAINING A NONDIFFUSING COUPLER, THE IMPROVEMENT CHARACTERIZED IN THAT AT LAST ONE OF SAID ELEMENTS IS COMPOSED OF THREE ADJACENT GELATINO SILVER HALIDE EMULSION LAYERS AND FURTHER CHARACTERIZED IN THAT (A) THE SENSITIVITY OF SAID UPPERMOST EMUSLION LAYER BEING THE HIGHEST AND THAT OF THE LOWERMOST EMULSION LAYER BEING THE LOWEST, (B) THE MAXIMUM OPTICAL DENSITY OF SAID UPPERMOST EMULSION LAYER AND THE MAXIMUM DENSITY OF SAID INTERMEDIATE EMULSION LAYER BEING AT MOST 0.60, RESPECTIVELY, (C) SAID UPPERMOST EMULSION LAYER, SAID INTERMEDIATE EMULSION LAYER, AND SAID LOWERMOST EMULSION LAYER BEING SENSITIVE TO THE SAME SPECTRAL REGION OF VISIBLE LIGHT, AND (D) THE SENSITIVITY DIFFERENCE BETWEEN SAID UPPERMOST EMULSION LLAYER AND SAID INTERMEDIATE EMULSION LAYER AND THE SENSITIVITY DIFFERENCE BETWEEN SAID INTERMEDIATE EMULSION LAYER AND SAID LOWERMOST EMULSION LAYER EACH RANGING FROM ABOUT 0.15 TO ABOUT 0.6 SAID SENSITIVITY OF EACH OF SAID EMULSION LAYERS BEING INDICATED BY THE LOGARITHM OF THE INERTIA POINT THEREOF.

Description

United States Patent 3,843,369 MULTI-LAYER COLOR PHOTOGRAPHIC LliGHT- SENSITIVE MATERIALS Akira Kumai and Toshimasa Usami, Minami-ashigara,

Japan, assignors to Fuji Photo Film (10., Ltd, Minamiashigara-shi, Kanagawa, Japan No Drawing. Continuation-in-part of abandoned application Ser. No. 29,666, Apr. 17, 1970. This application June 2, 1972, Ser. No. 259,109

Claims priority, application Japan, Apr. 17, 1969, 44/ 29,835 Int. Cl. G03c 7/00 U.S. CI. 96-74 Claim;

ABSTRACT OF THE DISCLOSURE A gelatino-silver halide color photographic multilayer light-sensitive material comprising a support having thereon a red-sensitive element, a green-sensitive element and a blue-sensitive element, each of said elements containing a nonditfusing coupler, the improvement characterized in that at least one of said elements is composed of three adjacent gelatino-silver halide emulsion layers having improved granularity is disclosed.

Cross Reference to Related Applications This is a continuation-in-part application of Ser. No. 29,666 filed Apr. 17, 1970, now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the invention The present invention relates to a multilayer color photographic light-sensitive material and more particularly to a multilayer color photographic light-sensitive material having light-sensitive emulsion layers each containing silver halide grains and a nondifiusing color coupler as the main components and capable of providing color images having improved granularity on developing in a color developer containing an aromatic primary amino developing agent.

2. Prior art A color photographic light-sensitive material containing couplers in the light-sensitive emulsion layers thereof generally is composed of a support having thereon a redsensitive silver halide emulsion layer containing a cyanforming coupler, a green-sensitive silver halide emulsion layer containing a magenta-forming coupler, and a bluesensitive silver halide emulsion layer containing a yellowformin-g coupler.

In general, a color camera film is prepared by applying to a support, such as a cellulose ester film, a polyester film and the like, a subbing layer, a red-sensitive layer, a greensensitive layer, a yellow filter layer, and a blue-sensitive layer in this order. Furthermore, a gelatin protective layer is generally applied as the uppermost layer.

The silver halide emulsions frequently used for such multilayer type color photographic light-sensitive elements are the socalled mixed emulsions, that is, emulsions comprising a combination of a more sensitive emulsion, containing coarse silver halide grains, and a less sensitive emulsion, containing fine silver halide grains, whereby a desired gradation can be obtained.

As couplers to be incorporated in each of the silver halide emulsions, there can be employed colorless couplers as well as a combination of colorless and colored couplers, or a combination of colorless couplers and compounds capable of forming colorless compounds by the reaction with an oxidized developing agent.

Hitherto, it has been well-known that the granularity of a dye image depends almost entirely upon the size of the silver halide grains employed and sometwhat upon the type of the couplers used. However, since the size of silver halide grains is generally proportional to the sensitivity of the silver halide grains, that is, the sensitivity of silver halide grains is reduced as the size of the silver halide grains becomes finer, attempts toward improving the granularity of dye image of a color photographic lightsensitive element by reducing the size of the silver halide grains incorporated in the emulsion layer while maintaining the high sensitivity of the emulsion layer inevitably encounters a limit.

While a method of improving the granularity of the dye image by selecting certain couplers has been proposed, such an attempt is usually accompanied with various difliculties due to the requirements concerning the color hue of the dye image and other properties of couplers.

For example, the examples of German Pat. No. 1,121,470 or British Pat. No. 923,045, describe that the sensitivity of a multi-layer color photographic light-sensitive material can be increased without coarsening the granularity of the dye image in those parts of the H-D curve, which is important for the image. This is accomplished by applying separately the more sensitive emulsion layer and the less sensitive emulsion layer, sensitive to the same region of the visible spectrum and each containing couplers resistant to dilfusion and providing a substantially identical color hue upon color development, with the maximum color density of the more sensitive emulsion layer being adjusted to be lower than that of the less sensitive emulsion layer, in particular, to from 0.20 to 0.60. The maximum color density of the more sensitive emulsion layer can be adjusted to from 0.20 to 0.60 without loss of sensitivity by (l) lowering the concentration of the coupler in the more sensitive: emulsion layer (in this case, it is believed that the oxidation product of an aromatic primary amino developing agent formed during development of silver halide grains must cover a large distance to find a coupler with which it can couple, and provides a dye image having indefinite structure, whereby the granularity is improved), (2) using together a material forming a colorless compound on coupling, or (3) using a coupler which produces a final color density lower than that produced from the coupler incorporated in the less sensitive emulsion layer.

The inventors have confirmed that the aforesaid method (1) is excellent in various points in the case of adjusting the maximum coupling density of high-sensitive emulsion layer.

The granularity of the less sensitive emulsion layer can also be improved by lowering the concentration of coupler but this method is not always effective in obtaining a desired maximum density and/or gradation. However, when the above-mentioned two-layer system is employed, the oxidation product of an aromatic primary amino color photographic developing agent formed by developing ex-- posed coarse silver halide grains in the more sensitive emulsion layer difiuses into an adjacent less sensitive emulsion layer having a higher coupler concentration than that of the more sensitive emulsion layer to form therein coarse dye aggregates.

Consequently, the granularity of the parts of the H-D curve for the image is influenced by the more sensitive coarse silver halide grains and the granularity of the image is degraded.

Moreover, recently higher sensitivity has been required in camera color films and the silver halide grains of the aforesaid less sensitive emulsion layer become inevitably coarser. Therefore, even if the aforesaid two-layer system is employed, the degrading tendency of the granularity cannot be avoided.

3 SUMMARY OF THE INVENTION It has been discovered that one or both of the afore said difficulties can be overcome by dividing a light-sensitive silver halide emulsion layer into at least three emulsion layers sensitive to the same spectral region of visible light. The result is that the granularity of the color image obtained can be improved.

Detailed Description of the Invention For example, in dividing a light-sensitive emulsion layer into three light-sensitive emulsion layers sensitive to the same spectral region of visible light, the light-sensitive emulsion layers are so arranged that the uppermost emulsion layer has the highest sensitivity, the intermediate emulsion layer has an intermediate sensitivity, and the lowermost emulsion layer has the lowest sensitivity. The sensitivity of each emulsion layer is indicated by the log exposure of the inertia point as described in CBK Mees, The Theory of the Photographic Process, 3rd Ed., pp. 72-73. Macmillian Co., New York. As was described hereinabove, the light-sensitive emulsion layer of this invention is divided into at least three layers of varying sensitivity to the same spectral region. To obtain the objects of this invention the sensitivity relationships between the sensitivity of the layer of highest sensitivity and the sensitivity of the layer of intermediate sensitivity is a sensitivity difference ranging from about 0.15 to about 0.6, preferably difference ranging from about 0.2 to about 0.45. Similarly the sensitivity difference between the layer of intermediate sensitivity and the layer of lowest sensitivity ranges from about 0.15 to about 0.6, preferably a difference ranging from about 0.2 to about 0.45. By employing these layers of differing sensitivities and the sensitivity relationships set forth above the advantages of this invention can be obtained. Each emulsion layer has sensitivity in the same spectral region of visible light. By reducing the coupler content in the uppermost emulsion layer and the intermediate emulsion layer (by increasing the stoichio-metrical molar ratio of the silver halide to the coupler up to about from 20 to 120), keeping the maximum color density of each emulsion layer less than 0.60, and also keeping the sum of the two maximum color densities less than 1.00, only dye aggregates having indefinite structure are formed due to the low concentration of coupler in the intermediate emulsion layer, even if the oxidation product of a color developing agent formed by the development of the exposed coarse silver halide grains in the uppermost layer diffuses into the intermediate emulsion layer. Moreover, the oxidation product of a color developing agent formed by development of the silver halide grains in the intermediate emulsion layer forms dye aggregates having indefinite structure and hence the granularity of the image is not degraded due to the low concentration of coupler in the intermediate layer. Because of the presence of the emulsion layer having the intermediate sensitivity, a desired H-D curve can easily be obtained by incorporating only fine silver halide grains in the lowermost emulsion layer.

In particular, if it is desired to overcome only the aforesaid first difiiculty, this can be achieved only by reducing the concentration of coupler in the intermediate emulsion layer less than a certain value. Hence, in an extreme case, the emulsion layer can be a silver halide emulsion layer containing no coupler or even can be a simple gelatin layer containing neither coupler nor silver halide grains. ,1

In the case of applying the present invention, other well-known means of improving the granularity of dye image, such as using a silver halide emulsion having a finer grain size, using a coupler capable of providing finer dye aggregates, and the like, be applied, together making the effect of the present invention more advantag us- The aforesaid system of the present invention is applied effectively to a cyan-forming emulsion layer, a magentaforming emulsion layer, and a yellow-forming emulsion layer. When a multi-layer color photographic light-sensitive material is prepared using cyan-, magenta and yellowforming emulsion layers, each layer being divided into at least three emulsion layers according to the present invention, the granularity of the dye image formed in each of the emulsion layers is improved and also, the granularity of the resulting overall dye image becomes markedly improved. E

In the above-mentioned explanation of this invention, the silver halide emulsion layer, sensitive to the same spectral region of visible light, is composed of three emulsion layers but it will be understood that the emulsion layer can be composed of four or more emulsion layers. For preparing the multi-layer type color photographic light-sensitive materials of the present invention, the multi-layer coating system disclosed in the specification of US. Pat. No. 2,761,791 is suitable.

It is of course possible to improve the granularity of the dye image of one-specific emulsion layer or layers of cyan-, magenta-, and yellow-forming emulsion layers by the application of this invention. The present invention can also be effectively applied to a single layer light-sensitive element, for example, the invention can be utilized for improving the granularity of the dye image of printing magenta contact screen.

.jOn comparing the color photographic light-sensitive element employing the present invention, with a conventional color photographic light-sensitive element, assuming the granularity of the dye images is the same in both cases, an emulsion containing coarser silver halide grains can be used in this invention when compared with the conventional case, and in general, a color photographic light-sensitive element having high sensitivity can be obtained according to the present invention.

The nondiffusing couplers used in the present invention are all incorporated in the silver halide emulsion layer of the light-sensitive element and as the nondiffusing couplers, there can be employed various compounds as described in, for example, W. Pelz, Mitteilung aus Agfa Aktien Gesellschaft, Leverkusen, 3, 111-174 (1961).

The color developing agents used for developing the color photographic light-sensitive element of the present invention are aromatic primary amine derivatives and various compounds as described in T. H. James, The Theory of the Photographic Process, pp. 294295, Macmillan Co., New York, can be used.

The following examples are merely illustrative and are not to be considered as limiting the invention.

Example 1 I I CH CHz OH CI'IgCH: OH

20 parts by weight of a 1% aqueous solution of 5-methyl- 7-hydroxy-2,3,4-triazaindolizine, and 250 parts by weight of a 5% aqueous solution of compound (II) havin the following formula SO Na I SOsNa The thus prepared silver halide emulsion is called Emulsion LA-l.

(b) To 1000 parts by weight of an intermediately sensitive intermediategrain silver iodobromide Emulsion A-2, containing 4.5 g. of silver iodobromide (containing 4.0 mole percent silver iodide) and 16 g. of gelatin per 100 g. of the emulsion, were added successively 80 parts by weight of a 0.1% methanol solution of the compound (I) shown above, parts by weight of a 1% aqueous solution of 5-methyl-7-hydroxy-2,3,4-triazaindolizine, and 120 parts by weight of a 5% aqueous solution of the compound (II) shown above with stirring at 40 C. The emulsion thus prepared is called Emulsion LA-Z".

(c) To 1000 parts by weight of mixed emulsion of 600 parts by weight of the Emulsion A1 and 400 parts by weight of the Emulsion A-2 were added successively at 40 C. with stirring 90 parts by weight of a 0.1% methanolic solution of the compound (I) shown above, 20 parts by weight of a 1% aqueous solution of 5-methyl-7-hydroxy-2,3,4-triazaindolizine, and 250 parts by weight of a 5% aqueous solution of the compound (II) shown above. The emulsion thus prepared above is called Emulsion LA-3.

(d) To 1000 parts by weight of a high-sensitive coarsegrain silver iodobromide Emulsion A-4, containing 4.5 g. of silver iodobromide (containing 6.0 mole percent iodide) and 16 g. of gelatin per 100 g. of the emulsion, were added successively with stirring at 40 C., 70 parts by weight of a 0.1% aqueous solution of 5-methyl-7-hydroxy-2,3,4-triazainclolizine, and 90 parts by weight of a 5% aqueous solution of the compound (II). The emulsion thus prepared is called Emulsion LA-4.

By using these four silver halide emulsions prepared above, color photographic light-sensitive films having the following arrangements were prepared.

Film 1: Silver halide Emulsion LA-l was applied onto a cellulose acetate film having an ordinary subbing layer at a dry thickness of 4.5 microns.

Film 2: Silver halide Emulsion LA-3 was applied to a cellulose acetate film having an ordinary subbing layer at a dry thickness of 3.8 microns and then silver halide Emulsion LA-4 was further applied onto the emulsion layer at a dry thickness of 1.3 microns. The sensitivity difference between emulsion layer prepared from LA-3 and emulsion layer prepared from LA-4 was 0.3.

Film 3: Silver halide Emulsion LA-l was applied onto a cellulose acetate film having an ordinary subbing layer at a thickness of 3.3 microns and the silver halide Emulsions LA-2 and LA-4 were further applied onto the emulsion layer LA1 in this order at a dry thickness of 0.8 microns and 1.3 microns respectively. The sensitivity difference between emulsion layer prepared from LA-1 and emulsion layer prepared from LA-2 was 0.25 and the sensitivity difference between emulsion layer prepared from LA-2 and emulsion layer prepared from LA-4 was 0.25.

Each of the light-sensitive films thus prepared was exposed to red light through a gray step wedge having a density rise of 0.15 and then subjected to the following processings:

1. Color Development (8 minutes, 20 C.)

Composition of the Color Developer 7 G. p-Diethyl-phenylene Diamine Sulfate 2.75 Hydroxylamine Sulfate 1.2 Anhydrous Sodium Sulfite 2 Potassium Bromide 2 Sodium Carbonate 75 Water to make ml.

2. Hardening (8 minutes, 20 C.)

Composition of the Hardening Solution G. Glaubers Salt 100 Water to make 1000 ml.

3. First Fixing (5 minutes, 20 C.)

Composition of the Fixing Solution G. Hypo Water to make 1000 ml.

4. Water Washing (5 minutes, 20 C.) 5. Bleaching (5 minutes, 20 C.)

Composition of the Bleaching Solution G. Potassium Ferricyanide 100 Water to make 1000 ml.

6. Water Washing (5 minutes, 20 C.) 7. Second Fixing (5 minutes, 20 C.)

Same composition as that of the first fixing 8. Water Washing (20 minutes, 20 C.)

The optical density of the color wedge image thus obtained was measured through a red filter.

The results showed that Film 2 had substantially the same sensitivity and gradation as Film 3, Film 1 had the same gamma value as the gamma value of Film 3, and Film 1 had a sensitivity lower than the sensitivities of Film 2 and 3 by 0.50 in logarithmic units.

The granularity of the dye images of the films having an optical density of 0.6 was estimated by Selwyns G value (see Phot. 1., 79, 513 (1939)). The results are shown in the following table.

In order to increase the sensitivity by 0.50 in logarithmic units and to obtain a smooth H-D curve in the ordinary two-layer type Film 2, it was necessary to use a mixed emulsion containing relatively coarse grains for the less sensitive undercoat emulsion layer thereof, and further, since in this conventional two-layer type light-sensitive film, the less sensitive silver halide layer containing a high coupler concentration was adjacent to the more sensitive coarse grain silver halide emulsion layer, coarse dye aggregates having a high density were formed in the less sensitive layer and hence the granularity of total dye image was degraded. On the other hand, in Film 3 of the present invention, the sentitivity of the film was increased by 0.50 without degrading the granularity of the dye lmage.

Example 2 Four kinds of green-sensitive emulsions were prepared as follows:

(a) To 1000 parts by weight of a low-sensitive finegrain silver iodobromide Emulsion B-1, containing 8 g.

of silver iodobromide (containing 6.0 mole percent of silver iodide) and 12 g. of gelatin, were added successively at 40 C., 150 parts by weight of a 0.1% methanol solution of compound (III) having the following formula 0211. heat-.. (52115 N (III) 20 parts of a 1% aqueous solution of 5-methyl-7-hydroxy- 2,3,4-triazaindolizine, and 450 parts by weight of a magenta-forming coupler dispersion having the following composition Magenta Coupler (IV) The mixture was emulsified for 15 minutes by means of an ultrasonic mixer. The silver halide emulsion thus prepared was called Emulsion LB-l.

(b) To 1000 parts by weight of an intermediate-sensitive intermediate-grain silver iodobromide Emulsion B-2, containing 8 g. of silver iodobromide (containing 3.3 mole percent silver iodide) and 12 g. of gelatin per 100 g. of the emulsion, were added successively at 40 C., 100 parts by weight of a 0.1% methanol solution of the compound (III), 20 parts by weight of a 1% aqueous solu tion of 5-methyl-7-hydroxy-2,3,4-triazaindolizine and 120 parts by weight of the magenta-forming coupler dispersion having the aforesaid composition. The emulsion thus prepared was called Emulsion LB-2.

(c) To 1000 parts by weight of a mixed emulsion consisting of 600 parts by weight of the Emulsion B-l mentioned above and 400 parts by weight of the Emulsion B-Z mentioned above were added successively at 40 C. with stirring 130 parts by weight of a 0.1% methanol solution of the compound (III) shown above, 20 parts by weight of a 1% aqueous solution of 5-methyl-7-hydroxy- 2,3,4-triazaindolizine, and 450 parts by weight of the magenta-forming coupler dispersion having the aforesaid composition. The silver halide emulsion thus prepared was called Emulsion LB-3.

' (d) To 1000 parts by weight of a high-sensitive coarsegrain silver iodobromide emulsion, containing 8 g. of

silver iodobromide (containing 3.3 mole percent silver iodide) and 12 g. of gelatin per 100 g. of the emulsion, were added successively at 40 C. with stirring, 80 parts by weight of a 0.1% methanol solution of the compound (III), 15 parts by weight of a 1% aqueous solution of 5- methyl-7-hylroxy-2,3,4-triazaindolizine, and 120 parts by weight of a magenta-forming coupler dispersion having the aforesaid composition. The silver halide emulsion thus prepared was called Emulsion LB-4.

By using the four silver halide emulsions prepared 'above, the following three color photographic light-sensitive films were prepared.

Film 4: *Emulsion IB-1 was applied onto a cellulose acetate film having an ordinary subbing layer at a dry thickness of 4.5 microns.

Film 5: Emulsion LB-3 prepared above was applied onto a cellulose acetate film having an ordinary subbing layer at a dry thickness of 4.0 1 and then silver halide emulsion LB4 was further applied onto the emulsion layer at a dry thickness of 1.5 microns. The sensitivity difference between emulsion layer prepared with LB-3 and LB-4 was 0.3.

Film 6: Emulsion LB-l was applied onto a cellulose acetate film having an ordinary subbing layer at a thickness of 3.6 microns and thereafter Emulsion LB-1 and Emulsion LB-2 were applied onto the emulsion layer at dry thickness of 0.8 micron and 1.5 microns, respectively. The sensitivity difference between emulsion layer prepared with LB-l and LB-2 was 0.25 and between emulsion layer prepared with LB-2 and LB4 was 0.25.

Each of the light-sensitive films thus prepared was exposed to green light through a gray step wedge having a density rise of 0.15 and subjected to the same processing as in Example 1.

The optical density of the color wedge image thus obtained was measured through a green filter.

The results showed that Films 4 to 6 had substantially the same gamma value, the conventional two-layer type of Film 5 had the same sensitivity as that of the three layer type Film 6 of the present invention, and the sensitivity of the Film 4 was lower than the sensitivities of Films 5 and 6 by 0.50 in logarithmic unit.

Then the granularity of the color image of each film was measured at an optical density of 0.6, the results of which are shown in the following table:

Thus, in order to increase the sensitivity by 0.50 in logarithmic units and to obtain a smooth gradation curve in the conventional two-layer type light-sensitive Film 5, it was necessary to employ a mixed emulsion containing relatively coarse grains for the less sensitive silver halide emulsion layer thereof. Furthermore in the conventional two-layer type Film 5, the less sensitive emulsion layer having a high coupler concentration was adjacent to the more sensitive emulsion layer with coarse grains, resulting in the formation of coarse dye aggregates having a high density and degrading the granularity of the dye image. On the other hand, the three-layer type Film 6 of this invention has a sensitivity higher by 0.50 without degrading the granularity of the color image as compared with Film 4, having the same gamma value as that of the Film 6.

Example 3 Four kinds of blue-sensitive emulsions were prepared in the following manner.

(a) To 1000 parts by weight of the silver iodobromide Emulsion Al as shown in Example 1 were added at 40 C. with stirring 20 parts by weight of a 1% aqueous solution of 5-methyl-7-hydroxy-2,3,4-triazaindolizine and 500 parts of a 5% aqueous sodium hydroxide solution of compound (V) shown below and thereafter, the pH of the emulsion was adjusted to 6.5 with a 2% aqueous solution of citric acid.

CnHaaCONH-COCHzCONH-Q fIOOH (V) The emulsion thus prepared was called Emulsion LC-l.

(b) To 1000 parts by weight of the silver iodobromide Emulsion A-2 in Example 1 were added at 40 C. with stirring 20 parts of a 1% aqueous solution of -methyl- 7-hydroxy-2,3,4-triazaindolizine and 150 parts by weight of a 5% aqueous sodium hydroxide solution of compound (V), shown above and then the pH of the emulsion was adjusted to 6.5 with a 2% citric acid solution. The silver halide emulsion thus prepared was called Emulsion LC-Z.

(c) To 1000 parts by weight of a mixed emulsion consisting of 700 parts by weight of the silver iodobromide Emulsion A-l shown in Example 1 and 300 parts by weight of the Emulsion A-2 were added at 40 C. with stirring, parts by weight of a 1% aqueous solution of 5-methyl-7-hydroxy-2,3,4-triazaindolizine and 500 parts by weight of a 5% aqueous sodium hydroxide solution containing compound (V) shown above and then the pH of the emulsion was adjusted to 6.5 with a 2% aqueous citric acid solution. The silver halide emulsion thus prepared was called Emulsion LC3.

(d) To 1000 parts by weight of the silver iodobromide Emulsion A-4 shown in Example 1 were added at C. with stirring 20 parts by weight of a 1% aqueous solution of 5-methyl-7-hydroxy-2,3,4-triazaindolizir1e and 120 parts of a 5% aqueous sodium hydroxide solution containing compound (V) shown above then the pH of the emulsion was adjusted to 6.5 with a 2% aqueous citric acid solution. The silver halide emulsion thus prepared was called Emulsion LC-4.

. By using these four silver halide emulsions prepared above, three light-sensitive films were prepared in the following manner.

Film 7: Silver halide Emulsion LC-l prepared above was applied onto a cellulose acetate film having an ordinary subbing layer at a dry thickness of 5.0 microns.

Film 8: Silver halide Emulsion LC-3 prepared above was applied onto a cellulose acetate film having an ordinary subbing layer at a dry thickness of 4.2 microns and thereafter the silver halide Emulsion LC-4 was further applied to the emulsion layer at a dry thickness of 1.5 microns.

Film 9: Silver halide Emulsion LC-l was applied onto a cellulose acetate film having an ordinary subbing layer at a dry thickness of 3.8 microns and then silver halide Emulsion LC-l and Emulsion LC-2 were applied in this order onto the emulsion layer at a dry thickness of 0.8 micron and 1.5 microns, respectively.

Each of the light-sensitive films was exposed to blue- .light through a gray step wedge having an optical denvsity rise of 0.15 and then subjected to the processing as shown in Example 1.

The optical density of the color wedge image thus prepared was measured through a blue filter.

Film- 7 8 9 t The maximum densi- The maximum density of LC-2 ty of LC-4 was 0.30. was 0.20. The maximum density of L04 was 0.30. G-yalue" 0.34 0.45 0.35.

In order to increase the sensitivityby 0.50 in logarithmic units and, obtain a smooth gradation curve in the con- .ventional two-layer type light-sensitive Film 8, it was necessary to use the mixed emulsion, containing relatively coarse grains for the less sensitive emulsion layer and furthermore, in such a conventional film, the sensitive emulsion layer having a high coupler concentration was adjacent to the more sensitive emulsion layer having coarse grains, resulting in the formation of coarse dye aggregates having a high density and degrading the granularity of the color image. On the other hand, in the threelayer type light-sensitive Film 9 of the present invention, the sensitivity thereof was increased as compared with the ordinary light-sensitive Film 7 having the ame gamma value as that of Film 9 without degrading the granularity of color image.

Example 4 An antihalation layer mainly consisting of colloidal silver dispersed in aqueous gelatin was applied onto a cellulose acetate base having an ordinary subbing layer. To the antihalation layer were applied the emulsions shown below in multiple layers. By this procedure, three multi-layer color photographic fiilms were prepared as follows:

Film 10: On the aforesaid antihalation layer were coated the following emulsion layers in the following order:

(a) A layer of the red-sensitive Emulsion LB-l shown in Example 1 at a dry thickness of 4.5 microns.

(b) An intermediate gelatin layer at a dry thickness of 1.0 micron.

(c) A layer of the green-sensitive Emulsion LB-l shown in Example 2 at a dry thickness of 4.5 microns.

(d) A yellow filter layer consisting of yellow colloidal silver dispersed in gelatin at a dry thickness of 1.2 microns.

(e) A layer of the blue-sensitive Emulsion LC-l shown in Example 3 at a dry thickness of 5.0 microns.

(f) A protective layer of gelatin at a dry thickness of 1.2 microns.

Film 11: To the antihalation layer as mentioned above were applied the following photographic emulsion layers in the following order:

(a) A layer of the red-sensitive Emulsion LA-3 shown in Example 1 at a dry thickness of 3.8 microns and further a layer of the red-sensitive Emulsion LA4 at a dry thickness of 1.3 microns.

(b) An intermediate layer of gelatin at a dry thickness of 1.0 microns.

(c) A layer of the green-sensitive Emulsion LB-3 shown in Example 2 at a dry thickness of 4.0 microns and further a layer of the green-sensitive Emulsion LB-4 at a dry thickness of 1.5 microns.

(d) A yellow filter layer comprising yellow colloidal silver dispersed in gelatin at a dry thickness of 1.2 microns.

(e) A layer of the blue-sensitive Emulsion LC-3 shown in Example 3 at a dry thickness of 4.2 microns and further a layer of the blue-sensitive Emulsion LC-4 at a dry thickness of 1.5 microns.

(f) A protective layer of gelatin at a dry thickness of 1.2 microns.

Film 12: On the antihalation layer as described above were coated the following photographic emulsion layers in the following order:

(a) A layer of the red-sensitive Emulsion LA-l shown in Example 1 at a dry thickness of 3.3 microns, a layer of the red-sensitive Emulsion LA-2 at a dry thickness of 0.8 micron, and further a layer of the red-sensitive Emulsion LA-4 at a dry thickness of 1.3 microns.

(b) An intermediate layer of gelatin at a dry thickness of 1.0 micron.

(c) A layer of the green-sensitive Emulsion LB-l shown in Example 2 at a dry thickness of 3.6 microns, a layer of the green-sensitive Emulsion LB-2 at a dry thickness of 0.8 micron, and further a layer of the green-sensitive Emulsion LB-4 at a dry thickness of 1.5 microns.

(e) A layer of the blue-sensitive Emulsion LC-l shown in Example 3 at a dry thickness of 3.8 microns, a layer of the blue-sensitive Emulsion LC-2, dry thickness of 0.8 micron, and further a layer of the blue-sensitive Emulsion LC-4 at a dry thicknesss of 1.5 microns.

(f) A protective layer of gelatin at a dry thickness of 1.2 microns.

Each of the color photographic light-sensitive films thus prepared was exposed to red light, green light, blue light, and white light and then subjected to the processing as in Example 1. On each exposure, Film 11 had substantially the same sensitivity and gradation as that of Film 12 and the gamma value of Film 10 was the same as that of Film 11 and Film 12 but the sensitivity of Film 10 was lower than that of Films 11 and 12 by about 0.5 in logarithmic units.

Similar results to those of Examples 1 to 3 were obtained by measuring the granularities of the dye images of the above-mentioned Films 11 to 12.

Thus, in order to increase the sensitivity by 0.50 in logarithmic units compared with Film 10 and also to obtain smooth H-D curves using the conventional two-layer type light-sensitive color photographic film required the use of mixed emulsion containing relatively coarse grains for the less sensitive emulsion layers.

Furthermore, since the less sensitive emulion layer having a high coupler concentration was adjacent to the more sensitive emulsion layer having coarse grains, coarse dye aggregates having a high optical density were formed inevitably, degrading the granularity of the dye image. On the other hand, in the three-layer type color photographic Film 12 of the present invention, the granularity was not degraded.

Example 5 The following Emulsions (silver iodobromide) were prepared.

Iodide content,

Average grain mole percent size, ,u Emulsion number:

FPPPQFF oooooco ri t-. 995 un conomic: ocoaaooszco Emulsion Dry thickness, n D M13 Film 13 LO-1 s. o

14 LC-l 3. s

LC-2 0. s 0. 20 LC-4 1. 0. 30

LC-2 O. 8 0. 2O LC-4 1. 5 0. 30

16 LC-G 3 8 LC-Z 0. 8 O. 20 L04 1.5 0.

'17 LC-l a. s

LC7 0. 8 0. 20 LC-4 1. 5 0. 3O

LC-8 0. 8 0. 20 LC-4 1. 5 0. 30

*The maximum density was determined in accordance with the pro oedure of Example 1.

Relative sensitivity of each layer are shown below:

Film 1 6-5 I i t 9 I r l o. 5 I l l I 9 I l I l l I I 5' I I I Film 14 i I I i l 1: LC-l ]O LC-l2 re;

I l I l l I l I I l l l I i I I I Film 15 7 Q I I I l j I i i I i I I l l I j j 1 l I I I I I I I Film 16 I I I l 6 otc-z etc-4 j I I LC-i I l l I j I l I I I I I i 7 I j 1 Film 17 l l l (I 7OLC-4 l l j i l I I I I I 1 I I i I I Film 18 o Lc 5 a I I j 0M4 The granularity of the dye image of films (optical density=0.6) and the shape of H-D curve was evaluated. The results obtained are summarized below.

loose or gentle).

From the above results, it is known demonstrated that only Film 14 which is in the scope of the invention shows good straight line of the H-D curve as well as low G-value. Thus, it will be understood that the relative sensitivity of each layer must be determined to be in the range set forth for the invention.

What is claimed is:

1. In a gelatino-silver halide color photographic multilayer light-sensitive material comprising a support having thereon a red-sensitive element, a green-sensitive element and a blue-sensitive element, each of said elements containing a nonditrusing coupler, the improvement characterized in that at least one of said elements is composed of three adjacent gelatino silver halide emulsion layers and further characterized in that (a) the sensitivity of said uppermost emuslion layer being the highest and that of the lowermost emulsion layer being the lowest,

(b) the maximum optical density of said uppermost emulsion layer and the maximum density of said intermediate emulsion layer being at most 0.60, respectively,

(c) said uppermost emulsion layer, said intermediate emulsion layer, and said lowermost emulsion layer being sensitive to the same spectral region of visible light, and

(d) the sensitivity difference between said uppermost emulsion layer and said intermediate emulsion layer and the sensitivity difference between said intermediate emulsion layer and said lowermost emulsion layer each ranging from about 0.15 to about 0.6 said sensitivity of each of said emulsion layers being indicated by the logarithm of the inertia point thereof.

2. A gelatino-silver halide color photographic'multilayer light-sensitive material as claimed in Claim 1, wherein the three adjacent gelatino silver halide emulsion layers are the red-sensitive element and comprise (a) a low sensitive fine grain gelatino silver halide emulsion layer,

(b) an intermediately-sensitive intermediate-grain gelatino silver halide emulsion layer, and

(c) a high-sensitive coarse-grain gelatino silver halide emulsion layer, wherein each of layers (a), (b) and (0) contain (1) a compound having theformula CHzCHzOH: i KdHiCmOH' I (I) 2 S-methyI- I-hydroXy-Z,3,4-triazaindolizine, and (3) acornpoundhaving the formula OHI.C./N\ U SOaNB SOQNB said layer (c') being nearest to the support in said red sensitive element.

3. A gelatino-silver halide color photographic multilayer light-sensitive material as claimed in Claim 1, wherein the three adjacent gelatino silver halide emulsion layers are the green s'ensitive element and comprise (a) a low sensitive fine grain gelatino silver halide emulsion layer,

(b) an interimediately-sensitive intermediate-grain gelatino silverihalide emulsion layer, and I (c) a high sensitive coarse-grain gelatino silver halide emulsion j layer, wherein each of layers (a), (b) and (c) contagn (1) a compound having the formula (III) (2) -methyl-7-hydroxy-2,3,4-triazaindolizine, and (3) a compound having the formula cnam-Q-o CHz-C ONE-Q said layer (c) being nearest to the support in said greensensitive element.

4. A gelatino-silver halide color photographic multilayer light-sensitive material as claimed in Claim 1, wherein the three adjacent gelatino silver halide emulsion layers are the blue-sensitive element and comprise (a) a low sensitive fine grain gelatino silver halide emulsion layer,

(c) a high-sensitive coarse-grain gelatino silver halide emulsion layer, wherein each of layers (a), (b) and (c) contain '(l) a compound hai ng the formula t I (IJOO H c,,H,5o0NH--cocn,ooNH@ OOH v (2) 5-methyl-7-hydroxy-2,3,4-triazaindolizine, and (3) a compound having the formula I SOaNa n (d) a gelatin layer,

(e) a green-sensitive emulsion layer comprising a low sensitive fine grain gelatino silver halide emulsion layer containing (1) a compound having the formula Leann O lrHa N zHs (III) 2) 5-methyl-7-hydroxy-2,3,4-triazaindolizine, and (3) a compound having the formula hin-Q-Q cu -o ONE-Q 5H1! 23 0 NH([) CH;

(f) a layer of yellow colloidal silver dispersed in gelatin,