Silver Halide Photographic Light-Sensitive Material

The present invention relates to a silver halide photographic light-sensitive material, especially relates to a silver halide photographic light-sensitive material for photo display use comprising an excellent balance between sensitivity and sharpness.

In recent years, there have been increasing displays by color photographic in department stores, platforms of subways, restaurants, lobbies of hotels, and so on.

A display method by such photo display includes a method in which an image formed on a support is displayed by light irradiated from an image side, and a method in which an image is displayed by light transmitted from a backside of the image. It is self explanatory that in such specific conditions as in a dark room or outdoor at night, the latter method can give a clearer image.

However, the transmission method displaying an image by transmitted light requires a light-sensitive material capable of providing an image with higher density than that of conventional one. Therefore, the amounts of silver and a coupler contained in the light-sensitive material used in this method increases inevitably to a large extent.

Further, a light-sensitive material for display, which is usually displayed in a large size, requires higher sharpness.

However, the increased amounts of silver and a coupler for obtaining a higher image density result in a thicker layer, which in turn causes such problems as deterioration of sharpness, insufficient drying, and sweating. A light-sensitive material for display is usually displayed by light transmitted from a backside of an image, so that a transparent support is normally used to get sharper image. However, the transparent support requires much more quantity of silver than a semitransparent support, which makes it difficult to keep sharpness in a satisfactory level.

It is conventionally known to use an anti-irradiation dye for improving sharpness. However, there is liable to be desensitized remarkably a light-sensitive material having a transparent support provided thereon with a dye enough to provide satisfactory sharpness for a photo display.

It is also a known method for improving sharpness to provide an antihalation layer on a side of a silver halide emulsion layer or on a backside thereof.

However, the antihalation layer provided on a side of a silver halide emulsion layer side results in lowered sensitivity due to reflection in exposure. Therefore, it is preferable to provide the antihalation layer on the backside. Even thereby, however, shapness is still not improved to a satisfactory level.

An object of the present invention is to provide a silver halide light-sensitive material used for a photo display in a transmission system and capable of forming an image comprising a sufficient image density and excellent sharpness.

The above object of the invention can be accomplished by a silver halide light-sensitive material having a support, provided there on at least one silver halide emulsion layer, and a backing layer provided on a reverse side of the silver halide emulsion layer, wherein the support is transparent, and the transmittances of the support, the support plus the backing layer, and the silver halide light-sensitive material in 450 nm, 550 nm and 700 nm satisfy the following equations;

wherein T.sub.0700, T.sub.0550 and T.sub.0450 represent the transmittances of the support in 700 nm, 550 nm and 450 nm, respectively; T.sub.A700, T.sub.A550 and T.sub.A450 represent the transmittances of the support plus the backing layer in 700 nm, 550 nm and 450 nm, respectively; T.sub.B700, T.sub.B550 and T.sub.B450 represent the transmittances of the silver halide light-sensitive material in 700 nm, 550 nm and 450 nm, respectively .

In the present invention, the transmittances of the support T.sub.0700, T.sub.0550 and T.sub.0450 are usually 85-99%, 85-99% and 80-99%, and preferably 90-99%, 90-99% and 90-99%, respectively.

In the invention, the transmittances are the average transmittances in five sites of a sample in 700, 550 and 450 nm, which are measured with a dual-wavelength automatic spectrophotometer Type 556 manufactured by Hitachi Co., Ltd.

In .alpha..sub.700 to .beta..sub.450, preferably .alpha..sub.700 is 0.25 to 0.45, .beta..sub.700 is 0.05 to 0.20, .alpha..sub.550 is 0.20 to 0.40, .beta..sub.550 is 0.15 to 0.40, .alpha..sub.450 is 0.20 to 0.40, and .beta..sub.450 is 0.20 to 0.35; more preferably .alpha..sub.700 is 0.28 to 0.38, .beta..sub.700 is 0.08 to 0.15, .alpha..sub.550 is 0.23 to 0.33, .beta..sub.550 is 0.17 to 0.30, .alpha..sub.450 is 0.25 to 0.35, and .beta..sub.450 is 0.23 to 0.33.

The support of the invention may be any one so far as it is transparent. The examples thereof include cellulose triacetate film, polyethylene terephthalate film, polycarbonate film, polystyrene film, and polypropylene film. Among them, polyethylene terephthalate film is preferable.

The thickness of the support is normally 150 to 250 .mu.m, and preferably 160 to 200 .mu.m.

In the light-sensitive material of the invention, an antihalation layer containing a light-absorbing substance (an antihalation agent) is provided on an opposite side of a light-sensitive emulsion layer.

This agent has an effect to prevent halation caused by the support by absorbing light transmitted through the emulsion layer.

The above antihalation agent includes various inorganic substances and organic substances (dyes) each having the above effect.

The inorganic substances include a colloidal metal. The organic substances include such dye as fixed to a polymer for stabilization (a kind of a mordant dye) so that it does not elute into a color developer. When the antihalation dye fixed to a polymer mordant is used, it is difficult not only to coat it uniformly but also to eliminate it after color developing, so that bleaching may be necessary.

The inorganic substances used in the invention are preferably colloidal silver and colloidal manganese, and more preferably colloidal silver. The above substances are preferably applied to a color photographic light-sensitive material because of decoloration property thereof. Colloidal silver is prepared in the following manner; silver nitrate dissolved in a gelatin solution is reduced in an alkaline condition in the presence of a reducing agent such as hydroquinone, phenidon, ascorbic acid, pyrogallol or dextrin; then, it is neutralized, cooled, and precipitated together with gelatin to remove the reducing agent and unnecessary salts by a noodle washing method. Colloidal silver dispersion comprising uniform grains can be prepared by forming colloidal silver grains in the presence of azaindene and mercaptan compounds in an alkaline reduction.

The antihalation dye used in the invention is requested to satisfy various conditions; it is to have good spectral absorption property by application; it is to be bleached perfectly without eluting easily from an emulsion layer and causing stain by remained dye after developing; it is to exert no bad actions such as fogging and desensitization to a light-sensitive emulsion; it is to have an excellent aging stability in a solution and a light-sensitive material without causing discoloration and fading.

So far, a lot of efforts have been concentrated on discovering the antihalation dyes which meet the above conditions, and many dyes have been proposed; an oxonol dye is described in U.S. Pat. Nos. 506,385, 3,247,127., Japan Patent Patent Publication Nos. 22069/1964 and 13168/1968; a styryl dye is described in U.S. Pat. No. 1,845,404; a merocyanine dye is described in U.S. Pat. Nos. 2,493,747, 3,148,187 and 3,282,699; a cyanine dye is described in U.S. Pat. No. 2,843,486; an anthraquinone dye is described in U.S. Pat. No. 2,865,752. In the invention, preferable is a high decomposable dye described in Japanese Patent O.P.I. Publication No. 327694/1987.

Among the above inorganic substances and dyes, most preferable is colloidal silver.

An addition amount of colloidal silver is usually 0.5 to 5.0 mg/dm.sup.2, and preferably 1.0 to 2.0 mg/dm.sup.2.

The light-sensitive material of the invention can be used either for a monochrome photographic light-sensitive material or for a color photographic light-sensitive material. Where it is used for the color photographic light-sensitive material, a yellow coupler, a magenta coupler and a cyan coupler normally used in the art can be used in a conventional manner. There may be used a colored coupler which has an effect of color adjustment, or a DIR coupler which releases a development inhibitor in developing. If necessary, more than two kinds of the above couplers may be used for one layer in combination, and one coupler may be used for more than two different layers.

The yellow coupler used in the invention includes a conventional open-chained ketomethylene type coupler, a benzoyl type coupler, an acetanilide type coupler, and a pivaloyl acetanilide type coupler. The examples thereof are described in U.S. Pat. Nos. 2,875,057, 3,265,506, 3,277,155, 3,408,194, 3,415,652, 3,447,928, and 3,664,841; Japanese Patent Publication No. 13574/1974, Japanese Patent O.P.I. Publication Nos. 29432/1973, 66834/1973, 10736/1974, 122335/1974, 28834/1975, and 132926/1975.

Among these yellow couplers, preferable is the pivaloyl acetanilide type coupler, and especially preferable is a diequivalent pivaloyl acetanilide coupler from the view-point of coloring.

An addition amount thereof is preferably 1.times.10.sup.-3 to 2 mol per mol of silver in a silver halide emulsion layer, and more preferably 1.times.10.sup.-2 to 8.times.10.sup.-1 mol per mol of silver.

The magenta coupler used in the invention includes a conventional 5-pyrazolone type coupler, a pyrazolobenzimidazole type coupler, a pyrazolotriazole type coupler, and an open-chained acylacetonitrile type coupler. The examples of these magenta couplers are described in Japanese Patent Publication Nos. 6031/1965, 6035/1965, 40757/1970, 27411/1972, and 37854/1974; Japanese Patent O.P.I. Publication Nos. 13041/1975, 26541/1976, 37646/1976, 105820/1976, 42121/1977, 123129/1978, 125835/1978, 129035/1978, 48540/1979, 29236/1981, 75648/1981, 17950/1982, 35858/1982, 146251/1982, and 99437/1984; British Pat. No. 1,252,418; U.S. Pat. Nos. 2,600,788, 3,005,712, 3,062,653, 3,127,269, 3,214,437, 3,253,924, 3,311,476, 3,419,391, 3,519,429, 3,588,319, 3,582,322, 3,615,506, 3,658,544, 3,705,896, 3,725,067, 3,758,309, 3,823,156, 3,834,908, 3,891,445, 3,907,571, 3,926,631, 3,928,044, 3,935,015, 3,960,571, 4,076,533, 4,133,686, 4,237,217, 4,241,168, 4,264,723, 4,301,235, and 4,310,623.

Among them, preferable are an anilinopyrazolone type coupler and a pyrazolotriazole type coupler.

An addition amount thereof is normally 1.times.10.sup.-3 to 2 mol per mol of silver in a silver halide emulsion layer, and preferably 1.times.10.sup.-2 to 8.times.10.sup.-1 mol per mol of silver. The cyan coupler used in the invention includes the derivatives of phenol and naphtol.

The examples of these cyan couplers are described in U.S. Pat. Nos. 2,423,730, 2,474,293, 2,801,171, 2,895,826, 3,476,563, 3,737,316, 3,758,308, and 3,839,044; Japan Patent O.P.I. Publication Nos. 37425/1972, 10135/1975, 25228/1975, 112038/1975, 117422/1975, 130441/1975, 109630/1978, 16353/1980, 29235/1981, 55945/1981, 65134/1981, 80045/1981, 99341/1981, 116030/1981, 104333/1981, 31953/1984, 124341/1984, and 209735/1985.

Among the above cyan couplers, preferable is a phenol type cyan coupler. An addition amount thereof is normally 1.times.10.sup.-3 to 2 mol per mol of silver in a silver halide emulsion layer, and preferably 1.times.10.sup.-2 to 8.times.10.sup.-1 mol per mol of silver.

An image stabilizer for preventing deterioration of a dye image may be incorporated into a light-sensitive material of the invention.

The image stabilizer includes a hydroquinone derivative, a gallic acid derivative, a phenol derivative and a bis compound thereof, hydroxycoumarone and a spiro compound thereof, a hydroxycumaran and a spiro compound thereof, a piperidine derivative, an aromatic amine compound, a benzodioxane derivative, a benzoxole derivative, a silicone compound, and a thioether compound. The examples thereof are described in British Pat. No. 1,410846; Japanese Patent O.P.I. Publication Nos. 134326/1974, 35633/1977, 147434/1977, 150630/1977, 145530/1979, 6321/1980, 21004/1980, 124141/1980, 3432/1984, 5246/1984, and 10539/1984; Japanese Patent Publication Nos. 31625/1973, 20973/1974, 20974/1974, 23813/1975, and 27534/1977; U.S. Pat. Nos. 2,360,290, 2,418,613, 2,675,314, 2,701,197, 2,704,713, 2,710,801, 2,728,659, 2,732,300, 2,735,765, 2,816,028, 3,069,262, 3,336,135, 3,432,300, 3,457,079, 3,573,050, 3,574,627, 3,698,909, 3,700,455, 3,764,337, 3,935,016, 3,982,944, 4,013,701, 4,113,495, 4,120,723, 4,155,765, 4,159,910, 4,254,216, 4,268,593, 4,279,990, 4,332,886, 4,360,589, 4,430,425, and 4,452,884.

The above image stabilizers are especially effective for a magenta dye image. A hindered phenol derivative, a hindered amine derivative and a benzotriazole derivative are effective for the cyan and yellow dye images, which are described in Japan Patent O.P.I. Publication Nos. 222853/1985 and 222854/1985.

Such hydrophobic compounds as the above couplers can be dispersed by conventional methods such as a solid dispersion method, a latex dispersion method, and an oil-in-water emulsification method.

The oil-in-water emulsification can be carried out by the following conventional method; couplers are dissolved independently or in a mixture in a high boiling organic solvent including phthalate such as dibutyl phthalate and dioctylphthalate, phosphate such as tricresyl phosphate, triphenyl phosphate and trioctyl phosphate, and N,N-dialkyl amide such as N,N-diethyllauryl amide, and in a low boiling organic solvent such as ethyl acetate, butyl acetate and butyl propionate, or if necessary in a mixture thereof; the above solution is mixed with a gelatin solution containing an anionic, nonionic or cationic surfactant, and then it is dispersed to an emulsion with a high speed rotation mixer, a colloid mill or a supersonic disperser.

A gelatin used in the invention includes a gelatin derivative such as acylated gelatin, guanidinated gelatin, carbaminated gelatin, cyanohydroxyethylated gelatin, and esterified gelatin.

In the present invention, there is no limit to a layer constitution of a light-sensitive material. Preferably, however, a cyan dye image-forming layer of the silver halide emulsion layers is provided furthest from a support; more preferably, there are provided on the support, a magenta dye image-forming layer, an intermidiate layer, a yellow dye image-forming layer, a UV-absorbing layer, a cyan dye image-forming layer, a UV-absorbing layer, and a protective layer in this order from the support; or a yellow dye image-forming layer, an intermidiate layer, a magenta dye image-forming layer, a UV-absorbing layer, a cyan dye image-forming layer, a UV-absorbing layer, and a protective layer in this order from the support. Especially preferable is the latter.

In the present invention, conventional silver halide such as silver bromide, silver bromoiodide, silver chloroiodide, silver bromochloride and silver chloride is contained in an emulsion.

Silver halide grains may be formed by any of an acid method, a neutral method and an ammonium method. The grains may be grown either as they are or via seed grains. The methods for preparing the seed grains and growing them may be the same or different.

A silver halide emulsion may be prepared either by adding simultaneously a halide ion and a silver ion or by adding one of the above ions to a solution containing the other. Further, in view of a critical growth rate of a silver halide crystal, it may be grown by adding the halide and silver ions under control of pH and pAg in a reactor. A composition of silver halide grains may be varied by a conversion method after completion of growth.

There may be controlled a grain size, a grain form, a distribution of a grain size, a growing speed of a grain by adding a silver halide solvent in preparing a silver halide emulsion, if necessary.

In forming and/or growing grains, a metal ion may be doped therein and/or thereon by adding a cadmium salt, a zinc salt, a lead salt, a thallium salt, an iridium salt or a complex thereof, a rhodium salt or a complex thereof, and an iron salt or a complex thereof; further reduction sensitizing nucleus may be provided therein and/or thereon by letting it stand in a reduction condition.

Soluble waste salts may be removed from a silver halide emulsion after finishing growth of grains, or may be contained therein as they are. They can be removed by a method described in Research Disclosure 17643.

Silver halide grains may be either of uniform or different compositions in a core and an outer shell.

A latent image may be formed mainly on a surface of a silver halide grain or therein.

A silver halide grain may be of an isotropic crystal or of an anisotropic crystal such as cube and plate, in which a ratio of (100) face to (111) face may be arbitrary. It may be of a complex crystal or a mixture of various crystals.

Further, there may be mixed more than two kinds of silver halide emulsions which are prepared independently. A silver halide emulsion is chemically sensitized by a conventional method such as a sulfur sensitizing method, a selenium sensitizing method, a reduction sensitizing method, and a noble metal method, singly or combinedly.

A silver halide emulsion is spectrally sensitized to a desired wavelength range by a sensitizing dye. The sensitizing dye may be used singly or in combination of more than two. The other dyes or a supersensitizing dye may be incorporated into a silver halide emulsion.

An antifoggant and a stabilizer may be added to the emulsion.

In a light-sensitive material of the invention, a coated amount of silver is preferably not more than 30 mg/dm.sup.2, and more preferably 15 to 23 mg/dm.sup.2.

Gelatin is preferably used as a binder or a protective colloid for a silver halide emulsion. Besides above, there may be used a gelatin derivative, a graft polymer of gelatin with other polymers, protein, a sugar derivative, a cellulose derivative, and a hydrophilic colloid such as a homo- and copolymerized synthetic hydrophilic high-molecular compound.

A hydrophilic colloid layer is hardened with a hardener in order to crosslink binder molecules for reinforcing layer strength. The hardener may be incorporated either into a coating solution or a developing solution.

A light-sensitive material of the invention may incorporate a plasticizer for increasing flexibility, a synthetic polymer latex for improving size stability, an antistain agent for preventing color stain and deterioration of sharpness, and a UV absorber for preventing deterioration of image caused by ultra-violet light.

Subsidiary layers such as a filter layer, an antihalation layer and an anti-irradiation layer may be provided on a light-sensitive material of the invention. There may be incorporated into these layers and/or the light-sensitive layers a dye which elutes from the light-sensitive materials or is bleached in developing.

Further, the light-sensitive material of the invention may incorporate a surfactant, a matting agent, a lubricant and an antistatic agent. The antistatic agent may be provided on a side or a backside of an emulsion layer.

A subbing layer may be provided.

In the invention, a thickener may be used for improving efficiency of coating. There are applied preferably an extrusion coating method and a curtain coating method by which more than two layers are coated simultaneously.

The light-sensitive material of the invention may be exposed with a conventional light source such as natural light, a tungsten lump, a fluorescent lump, and a mercury lamp.

A primary aromatic amine color developing agent used in the invention includes a conventional color developing agent such as aminophenol and p-phenylenediamine derivatives. Usually, these compounds are used in a concentration of about 0.1 to 30 g per liter, preferably about 1 g to 15 g per liter of a color developer.

The aminophenol type developing agent includes o-aminophenol, 5-amino-2-oxytoluene, and 2-oxy-3-amino-1,4-dimethylbenzene.

The primary aromatic amine type color developing agent includes N-methyl-p-phenylenediamine hydrochloride salt, N,N-dimethyl-p-phenylenediamine hydrochloride salt, 2-amino-5-(N-ethyl-N-dodecylamino) toluene, N-ethyl-N-.beta.-methanesulfonamide ethyl-3-methyl-4-aminoaniline sulfate, N-ethyl-N-.beta.-hydroxyethylaminoaniline, 4-amino-3-methyl-N, N-diethylaniline, and 4-amino-N-(2-metoxyethyl)-N-ethyl-3-methylaniline-p-toluene sulfonate.

In the invention, the conventional compounds may be added to the color developer as well as the color developing agents.

pH of the color developer is normally not lower than 7, and preferably 10 to 13. A temperature thereof is normally not lower than 15.degree. C., and preferably 20.degree. C. to 50.degree. C. In rapid processing, it is preferably not lower than 30.degree. C. Developing time is preferably not longer than two and a half minutes, and more preferably 30 seconds to 2 minutes.

In the invention, bleaching and fixing may be carried out independently or simultaneously after developing. A metal complex of organic acid is used as a bleaching agent.

The examples thereof are shown as follows;

(1) Ethylenediamine tetraacetic acid

(2) Nitrilotriacetic acid

(3) Iminodiacetic acid

(4) Disodium ethylenediamine tetraacetate

(5) Tetra(trimethyl ammonium) ethylenediamine tetraacetate

(6) Tetrasodium ethylenediamine tetracetate

(7) Sodium nitrilotriacetate

A bleaching solution may contain conventional additives as well as the above metalic complex of organic acid.

Hereunder, the examples are shown to explain the invention in more detail. However, it is to be understood that the scope of the invention is not limited thereto

A silver halide emulsion is coated on a transparent polyethylene telephtalate film with thickness of 180 .mu.m, as shown in Table 1.

In the table, an addition amount is indicated by g/m.sup.2, and those of silver halide emulsion and colloidal silver are indicated by an amount converted to silver.

The amounts of a sign * are controlled so that .alpha..sub.700, .beta..sub.700, .alpha..sub.550, .beta..sub.550, .alpha..sub.450, and .beta..sub.450 become the values shown in Table 2.

The following dyes are used as a spectral sensitizer for each emulsion layer. ##STR1##

A sample was exposed by a conventional method, and processed in the following processes;

Water was added to make total quantity 1 liter. pH was adjusted to 10.0 with sodium hydroxide.

Water was added to 1 lit., and the pH was adjusted to 7.0 with aqueous ammonia.

Each sample was evaluated as follows;

(1) Sensitometry

The exposed and processed sample was subjected to sensimetory measurement with a sensitometer PDA-65 manufactured by Konica to obtain sensitivity and maximum density (Dmax).

(2) Sharpness

Each sample was exposed to blue light, green light and red light via a resolution test chart, and was processed in Process A. Then, each density of a yellow dye image, a magenta dye image and a cyan dye image on the processed sample was measured with a microphotometer, and sharpness was calculated by the following equation; ##EQU1##

The larger the value, the more excellent the sharpness is.

(3) Practicability

The processed sample was visually observed via reflected and transmitted light, and classified to five grades.

5: Very excellent

4: Excellent

3: Ordinary

2: Poor

1: No precticability

The evaluation results are summarized in Table 2.

As is apparent from Table 2, Samples 5 to 14 of which transmittances are within the scope of the invention comprise better balance between sharpness, sensitivity and Dmax, and higher practicabilities than Comparative Samples.

Samples were prepared and evaluated in the same manner as in Example 1, except that colloidal silver contained in the first and second backing layers of Sample 7 was replaced or used in combination with dyes AI-1, 2 and 3.

The result is shown in Table 3. The addition amounts of dyes are controlled so that the ratios of transmittances in each wavelength become the values shown in Table 3. ##STR2##

As is apparent from Table 3, the samples comprising AI dyes in place of colloidal silver exhibit the same results as in Example 1, as far as the transmittances in 450, 550 and 700 nm are within the scope of the invention.

The samples were prepared and evaluated in the same manner as in Examples 1 and 2, except that in Samples 1 to 14 of Example 1 and Samples 15 to 26 of Example 2, Y-1 was replaced with Y-2 to Y-6; M-1 with M-2 to M-9; C-1 and C-2 with C-3 to C-9; AS-1 with AS-2 and AS-3; high boiling solvents DNP, DOP and DIDP with DBP, TOP, TCP, TINP, TEHP, DCPP, and THP; AI dyes AI-1 to AI-3 with AI-4 to AI-11; an image stabilizer ST-1 with ST-5, 6 and 9, and ST-3 with ST-7, 8, 10, 11 and 12; and a UV absorber UV-1 and 2 with UV-3 to 5.

The evaluation results were equivalent to those of Examples 1 and 2.

DBP: dibutylphthalate

TOP: trioctylphosphate

THP: trihexylphosphate

TCP: tricresylphosphate

TEHP: tri(2-ethylhexyl) phosphate

TINP: tri-isononylphosphate

DCPP: dicresyl phenylphosphate ##STR3##

The samples were prepared and evaluated in the same manner as in Examples 1 and 2, except that in Samples 1 to 14 of Example 1 and Samples 15 to 26 of Example 2, the emulsions and the layer constitution were replaced with the following emulsions and that shown in Table 4, and Process A with Process B.

To 1,000 ml of 2% gelatin solution kept at 40.degree. C., the following solution A and solution B were added simultaneously in 30 minutes controlling pH and pAg at 3.0 and 6.5, respectively, and the solutions C and D were added simultaneously in 180 minutes at pH of 5.5 and pAg of 7.3, wherein pH was controlled with an aqueous sulfuric acid or an aqueous sodium hydroxide, and pAg was controlled with the method stated in Japan Patent O.P.I. Publication No. 45437/1984.

After finishing addition, the emulsion was subjected to desalination with a 5% solution of Demol N manufactured by Kao Atlas Co., Ltd. and a 20% solution of magnesium sulfate, and then was dispersed in a gelatin solution to obtain a monodispersed emulsion EMP-1 containing cubic silver halide grains having an average size of 0.85 .mu.m, a variation coefficient (.delta./r) of 0.07, and a silver chloride content of 99.5 mol %.

The above emulsion EMP-1 was subjected to chemical ripening at 50.degree. C. in 90 minutes with the following compounds to obtain a blue-sensitive silver halide emulsion EM-A.

The above prescription for EMP-1 was repeated, except that adding time of solutions A and B and solutions C and D was changed, to obtain a monodispersed emulsion EMP-2 containing cubic silver halide grains having an average size of 0.43 .mu.m, a variation coefficient (.delta./r) of 0.08, and an AgCl content of 99.5 mol %.

EMP-2 was subjected to chemical ripening at 55.degree. C. in 120 minutes with the following compounds to obtain a green-sensitive silver halide emulsion EM-B.

The prescription for EMP-2 was repeated to obtain a monodispersed emulsion EMP-3 containing cubic silver halide grains having an average size of 0.50 .mu.m, a variation coefficient of 0.08, and an AgCl content of 99.5 mol %.

EMP-3 was subjected to chemical ripening at 60.degree. C. in 90 minutes with the following compounds to obtain a red-sensitive silver halide emulsion EM-C.

Water was added to make total quantity 1 liter. pH was adjusted to 10 10.

Water was added to make total quantity 1 liter. pH was adjusted to 5.7 with potassium carbonate or glacial acetic acid.

Water was added to make total quantity 1 liter. pH was adjusted to 7.0 with sulfuric acid or potassium hydroxide.

In the table, an addition amount is indicated by g/m.sup.2, and those of silver halide emulsion and colloidal silver are indicated by an amount converted to silver. The values of a sign * are regulated so that the values of T.sub.A700, T.sub.A550 and T.sub.A450 become the same as those of Samples 1 to 14 of Example 1 and 15 to 26 of Example 2.

The evaluation results were equivalent to those of Examples 1 and 2. ##STR5##