US3713835A

US3713835A - Light-sensitive supersensitized silver halide photographic material

Info

Publication number: US3713835A
Application number: US00079941A
Authority: US
Inventors: S Saito; K Sakazume; S Sato; E Sakamoto; T Kaneko
Original assignee: Konica Minolta Inc
Current assignee: Konica Minolta Inc
Priority date: 1969-10-13
Filing date: 1970-10-12
Publication date: 1973-01-30
Anticipated expiration: 1990-01-30
Also published as: GB1297655A; DE2049967B2; JPS4828293B1; DE2049967A1; DE2049967C3

Abstract

Light-sensitive silver halide photographic material characterized by containing in the silver halide photographic emulsion layer thereof a combination of sensitizing dyes comprising at least one compound represented by the general formula (I),

wherein R1 and R2 are individually a lower alkyl group which may be in etherated form; R3 and R4 are individually a lower alkyl group, a hydroxyalkyl group or a sulfoalkyl group; Y1 and Y2 are individually a lower alkyl group which may be in etherated form, or an aryl group; X( ) is an anion (that is an acid anion); and n is an integer of 1 or 2, with at least one compound represented by the general formula (II),

wherein R5 is a lower alkyl group; and A is an alkylene group, or a combination of said compounds with at least one compound represented by the general formula (III),

wherein R6 is a lower alkyl group; R2 is a lower alkyl group, a hydroxyalkyl group, a carboxyalkyl group or a sulfoalkyl group; Y3 is a hydrogen atom, a lower alkyl group or a lower alkoxy group; Z is S or Se: X is a negative group; and n is an integer of 1 or 2.

Description

United States Patent no Sato et a1.

[451' Jan. 30, 1973 [54] LIGHT-SENSITIVE SUPERSENSITIZED SILVER HALIDE PHOTOGRAPHIC MATERIAL [75] Inventors: S l3ui Sato, Tokyo; Eiich i Sakamoto, 7

Hanna; Shizuo Sai'to, Kaiichiro Sakazume, both of Tokyo; Tokuzo Kaneko, Tokyo, all of J apan [73] Assignee: Konishiroku Photo Industry Co., Ltd., Tokyo, Japan [22] Filed: Oct. 12, 1970 [211 App]. No.1 79,941

[30] Foreign Application Priority Data Oct. 13,1969 Japan ..44/8ll51 [52] U.S.CI. ..96/124,96/l32,96/137, 96/139 [51] Int. Cl. ..G03c 1/14 [58] Field of Search ..96/124, 125,126

[56] References Cited UNITED STATES PATENTS 2,688,545 9/1954 Carroll et al. ..96/124 2,751,298 6/1956 Jones 96/124 3,348,949 10/1967 Bannert et a1 ....96/124 3,397,060 8/1968 Schwan et a1. ..96/l24 Primary Examiner-J. Travis Brown AttorneyWaters, Roditi, Schwartz & Nissen [57] ABSTRACT Light-sensitive silver halide photographic material ac e z b sent i jaflle si r. h l M1929: graphic emulsion layer thereof a combination of sensitizing dyes comprising at least one compound (X na-1 wherein R, and R are individually a lower alkyl group which may be in etherated form; R and R are individually a lower alkyl group, a hydroxyalkyl group or a sulfoalkyl group; Y, and Y are individually a lower alkyl group which may be in'etherated form, or

an aryl group; X is an anion (that is an acid anion); and n is an integer of 1 or 2, with at least one compound represented by the general formula (11),

wherein R is a lower alkyl group; and A is an alkylene group, or a combination of said compounds with at least one compound represented by the general formula (111),

- i1 (K nn-1 (111) wherein R is a lower alkyl group; R is a lower alkyl group, a hydroxyalkyl group, a carboxyalkyl group or a sulfoalkyl group; Y is a hydrogen atom, a lower alkyl group or a lower alkoxy group; Z is S or Se: X is a negative group; and n is an integer of l or 2.

9 Claims, 5 Drawing Figures LIGHT-SENSITIVE SUPERSENSITIZEI) SILVER IIALIDE PHOTOGRAPIIIC MATERIAL This invention relates to a light-sensitive silver halide photographic material incorporated with a combination of sensitizing dyes. More particularly, the invention pertains to a light-sensitive silver halide photographic material characterized by containing in the silver halide photographic emulsion layer thereof a combination of at least one compound represented by the general formula (I),

wherein R is a lower alkyl group; and A is an alkylene group, or a combination of said compounds with at least one compound represented by the general formula (III),

wherein R is a lower alkyl group; R, is a lower alkyl group, a hydroxyalkyl group, a carboxyalkyl group or a sulfoalkyl group; Y is a hydrogen atom, a lower alkyl group or a lower alkoxy group; Z is S or Se; X is a negative group; and n is an integer of l or 2.

As is well known, the light-sensitive wavelength region inherent to a silver halide emulsion is ordinarily limited to the wavelength region of such a short wave as ultraviolet light or blue light. It is well known that as a means for the spectral sensitization of such a silver halide emulsion, the use of a certain cya nine dye is quite effective. It is also well known that a combination of said sensitizing dye with a certain other sensitizing dye or with an organic compound is incorporated into a silver halide emulsion to impart to the emulsion a light sensitivity which is greater than thetotal sum of the light-sensitivities of the individual compounds. Such effect is called super-sensitization, and many such combinations have already been reported.

In applying such supersensitization process to a silver halide emulsion, it is desirable that the combination of compounds used can not only increase color sensitization effects but also satisfy the following conditions:

l. The combination should be proper in spectral sensitization area.

2. The combination should have no detrimental interaction with other photographic additives and should provide stable photographic properties even when emulsions incorporated with the combination are allowed to stand or films or printing papers containing the combination are stored for a long period of time.

3. The combination should not .leave any color stain or fog in films or printing papers after development treatment.

The above-mentioned conditions become more important in the case where the supersensitization process is applied to green-sensitive emulsions for light-sensitive color photographic materials. Further, the combination is required to satisfy the condition that even when used together with a magenta color image-forming agent, i.e. a magenta coupler, which couples with the oxidation product of a color developing agent containing p-phenylenediamine or the like in order to obtain a color image, the combination should not bring about a decrease of color sensitivity due to interaction with said magenta coupler. However, none of the known combinations of sensitizing dyes can satisfy the above-mentioned conditions. I

An object of the present invention is to provide a light-sensitive silver halide photographic material which has been subjected to supersensitization using a combination of sensitizing dyes capable of satisfying all the above-mentioned conditions. According to the present invention, the spectral maximum values of individual sensitizing dyes can be brought, by combination use of the sensitizing dyes, to a unified and collective spectral maximum value, and the optimum green sensitivity can be obtained.

Another object of the invention is to provide a lightsensitive silver halide photographic material having a high green light sensitivity which does not form any optical fog even when treated under a safety light having a wavelength of more than 600 mp We have now found that not only a marked increase of color sensitizing effect can be attained but also all the aforesaid conditions can be satisfied by adding to a silver halide emulsion a combination of at least one compound represented by the general formula (I) with at least one compound represented by the general formula (II) or a combination of said compounds with at least one compound represented by the general formula (III).

All the sensitizing dyes represented by the abovementioned formulas are ortho-type sensitizing, dyes. Among these, the sensitizing dye of the general formula (I) is a green-sensitive dye which, when used singly,

shows a color sensitization maximum in a long wavelength region (wavelength 570 mp. 580 mp) whereas the sensitizing dye represented by the general formula (ll) or (III) is a green-sensitive sensitizing dye which shows a color sensitization maximum in a short wavelength region (wavelength 550 mp. 560 my).

Accordingly, even when these sensitizing dyes are used r singly, it is impossible to obtain a green-sensitive silver halide emulsion having a sufficiently broad wavelength region of color sensitization. We have found that when there is used a combination of sensitizing dyes represented by the general formulas (l) and (II) or a combination of said sensitizing dyes with a sensitizing dye represented by the general formula (Ill), a marked green sensitization can be attained due to the synergistic effect of said sensitizing dyes. That is, we have found that by use of such combination as mentioned above, the long and short wavelength portions in the green sensitive area are supersensitized to obtain a green color sensitivity of a high degree as well as to attain green sensitization having a new color sensitization maximum which cannot be attained when the sensitizing dyes are used singly.

The combination used in the present invention is an excellent supersensitizing agent which has no detrimental interaction with other additives to be added to photographic emulsions and which leaves no color stain in films after development treatment.

Typical examples of the compounds represented by the aforesaid general formulas (I), (II) and (III) are enumerated below, but compounds usable in the present invention are not limited only to these.

Typical examples of the compounds represented by the aforesaid general formula (I) are:

92 (CHmOH I (-1 (s) 01E; 01E! M m m =CHCH=YCH- mcQ-ooccoo-@011; N (Q1? $zHn I CzHs =CHCH=GH H5CzOHzCH2COOC N COQCHzCHzOCzH: I onmsoan (cameos- Typical examples of the compounds represented by the aforesaid general formula (II) are:

my' i 20 g i N CH JZHE H2O OOH I Light-sensitive photographic materials, which have been supersensitized according to the present invention by use of such compounds as mentioned above, have excellent characteristics as mentioned previously and can impart an ideal green sensitivity to silver halide emulsions. Thus, the compounds used in the present invention show markedly excellent efficiencies as color sensitizers not only for green sensitive emulsions for high speed light-sensitive black-white photographic materials but also for green sensitive emulsions for light-sensitive color photographic materials.

The distribution of color sensitization maxima of silver halide-emulsions according to the present invention may vary depending on the kind and proportions of the sensitizing dyes represented by the aforesaid general formulas. These sensitizing dyes may be added to a silver halide photographic emulsion after dissolving the dyes in a water-miscible organic solvent such as methanol or ethanol. Alternatively, the sensitizing dyes may be added individually after dissolving each of the Anhydrous sodium sulfite dyes in such anorganic solvent as mentioned above.

Further, the sensitizing dyes may be added to a silver halide photographic emulsion at any stage. Generally,

however, 'the dyes are preferably added immediately after completion of the second ripening. The amounts of the sensitizing dyes vary depending on the kind of the silver halide emulsion used. Ordinarily, however, the total amount of the compounds of the general formulas (I), (ll) and (III) is in the range of 1 mg. to 100 mg. per kg. of the silver halide emulsion, wherein the weight ratio of the compound of the general formula emulsions, which may have been sensitized by means of noble metal sensitizers, sulfur sensitizers, reduction sensitizers or polyalkylene oxide type sensitizers. Further, the emulsions may be incorporated according to a known procedure with such additives as stabilizers, surface active agents and hardeners.

The present invention is illustrated in further detail below with reference to examples.

EXAMPLE 1 A silver iodobromide emulsion containing 3 mol percent of silver iodide which has been added with a gelatine coagulant was subjected to second ripening according to gold and sulfur sensitization to prepare a high speed negative photographic emulsion. This emulsion was divided into several portions, which were then incorporated with one or more of methanol solutions of such sensitizing .dyes' as shown in Table 1. Each of the thus treated emulsions was allowed to stand at about 40C. for minutes and then coated on a film base, followedby drying, to prepare a green-sensitive lightsensitive photographic material.

Using a sensitometer of Model KS-l (manufactured by Konishiroku Photo Industry Co., Ltd.), the thus preparedsamples were exposed to a 160 lux daylight lamp -(5,400K)' with a green filter having a transmission maximum at 525 my, and then developed at 20C. for 5 minutes with a developer of the following composition:

Metol (N-methyl-p-aminophenol. sulfate) g. g. Hydroquinone Sodium carbonate Potassium bromide Water to make g. 29. g. g.

The results obtained were as shown in Table 1. In-

Table 1, the relative speed is a value calculated by assuming as 100 the green sensitization of the sample prepared by using the exemplified dye (3) singly.

1 Compound (3) 6 mg. 0.04

2 liters 2 Compound(l3) 6 mg. no 0.04 555 3 Compound (3) 4 mg.

Compound (13) 2 mg. 160 0.03 575 4 Compound (3) 4 mg.

Compound (13) 3 mg. 170 0.03 575 s (8)6 mg. 0.04 580 6 Compound (15) 6 mg. 0.03 550 7 Compound (8) 4 mg.

Compound (15) 3 mg. 0.03 575 8 Compound (8) 3 mg.

Compound (15) 3 mg. 0.03 575 9 Compound (l8) 6 mg. 80 0.04 575 10 Compound (3) 2 mg.

+ Compound (l3) 2 mg. 0.04 575 Compound (18) 2 mg.

ll Compound (16) 6 mg. 85 0.04 550 12 Compound (3) 2 mg.

+ Compound 13) 2 mg. 0.03 575 Compound (l6) 2 mg.

As is clear from Table l and the accompanying drawings, it is understood that the samples (3), (4), (7), (8), (l0) and (12) according to the present invention are more excellent in green light sensitivity than the samples prepared by using the individual compounds singly.

In the accompanying drawings, FIGS. 1, 2 and 3 are spectral sensitivity curves of the samples (1), (2) and (11), and FIGS. 4 and 5 are spectral sensitivity curves of the present samples (4) and 12), respectively.

EXAMPLE 2 The same emulsions as in Example 1 were individually incorporated with each of such combinations of dyes as shown in Table 2. After sufficiently stabilizing the color sensitization thereof, the emulsions were individually added with a suitable amount of 4-hydroxy--methyl-l,3,3a,7-tetrazaindene and then coated on a film base, followed by drying, to prepare green-sensitive light-sensitive materials.

For comparison, a control sample was prepared in the same manner as above, except that there was used a combination of such sensitizing dyes as shown below which are-disclosed in U.S. Pat. No. 2,688,545. Control dye (A):

The thus prepared samples were individually subjected to incubation test at a high temperature and a high, humidity to obtain such results as shown in Table 2. In this example, the exposure and the development were effected in the same manner as in Example 1. 1n the table, the relative speed is a value calculated by assuming as 100 the relative speed of the control sample developed immediately after preparation, and the residual color is the .optical density measured by a sensitometer of the sample which has been freed from fog.

TABLE 2 Developed alterincubation for Developed im- 3 days at mediately alter prep- 50 C.,

aration 80% RH Amount of compound Rela- Resid- Rela- Sam le incorporated per kg. tive uel tive num er of emulsion speed Fog color speed Fog 13. Control dye (A) 3 100 0.04 0.04 90 0.05

mg. plus Control dye ('B) 3 mg. 14 Compound (1) 3mg. 160 0.03 0.02 150 0.03

plus Compound (11 3mg. Compound (3) 3 mg. 150 0.03 0.02 150 0.03

plus Compound I (12) 3 mg. 16 Compound (3) 3mg. 170 0.03 0.02 170 0.04

plus Compound (13) 3 mg.

Table 2 clearly shows that even when stored under severe conditions, the light-sensitive materials (14), (15) and (16) according to the present invention have excellent sensitivity without formation of fog and are less in residual color (color stain).

EXAMPLE 3 A high speed color negative silver iodobromide emulsion containing 5 mol percent of silver iodide was spectrally sensitized by addition of 50 mg. per kg. of the emulsion of anhydro-S ,5 '-dichloro-9-ethyl-3,3 '-disulfopropyl thiacarbocyanine as a red-sensitive sensitizing dye. e

Separately, 4-chlorol -hydroxy-2-(n)-octyl naphthamide as a cyan coupler was dissolved at an elevated temperature in a mixture of di-(n)-butyl phthalate and ethyl acetate, and the resulting solution was dispersed in a gelatine solution by use of sodium alkylbenzenesulfonate to prepare a dispersion. A definite amount of the thus prepared dispersion was added to the above-mentioned emulsion. This emulsion was adjusted to pH 6.3 and then coated on a film base so as to form a layer of 5 microns in thickness, and then gelatine was thinly coated on the said layer. Thereafter, the same high speed silver iodobromide emulsion as in Example 2 was divided into portions of 1 kg. in weight, and each of the divided emulsions was combined with one or more of methanol solutions of such sensitizing dyes as shown in Table 3. In this emulsion, l-(2,4,6-trichlorophenyl)-3- [3-(2,4-di-tert-amyl phenoxyacetamide) benzamide]- S-pyrazolbne as a magenta coupler was dispersed in the same manner as in the case of the cyan coupler. Subsequently, the emulsion was adjusted to pH 6.8 and then coated on the aforesaid gelatine layer so as to form a layer of 6 microns in thickness, and a yellow filter layer was further applied onto the thus formed la er.

Thereafter, 2-dodecyloxybenzoyl acetanilide as a yellow coupler was dispersed in the same manner as in the case of the aforesaid cyan coupler in a silver iodobromide negative emulsion, which had been sensitized according to gold and sulfur sensitization. This emulsion was adjusted to pH 6.8 and then coated on the above-mentioned yellow filter layer so as to form a layer of 5 microns in thickness.

The thus obtained multi-layered light-sensitive color photographic materials were exposed in the same manneras in Example 1, developed at 22C. for l0 minutes with a color developer having such a composition as shown below, and then subjected to bleaching, fixing and color sensitometry according to ordinary procedures.

N-Ethyl-N lfl-methanesulfonamide-ethyl- 3-methylaminoaniline sulfate 2.5 g. Anhydrous sodium sulfite 2.0 g. Benzyl alcohol 3.8 cc. Sodium hexametaphosphate 2.0 g. Sodium carbonate (monohydrate) 50.0 g. Potassium bromide 1.0 g. Sodium hydroxide 0.6 g. Water to make 1 liter The results obtained were as shown in Table 3. The relative speed shown in the table is a value calculated by assuming as the relative speed of the sample prepared by using the exemplified dye (4) singly.

+Compound (l4) 3 mg.

Table 3 clearly shows that the light-sensitive silver halide photographic materials according to the present invention (the samples l8, l9 and 20) are high in green sensitivity and less in fog and gamma, even when used as multi-layered color photographic materials containing magenta couplers.

EXAMPLE 4 A reversal color photographic silver iodobromide emulsion containing 3 mol percent of silver iodide which had been treated with a gelatine coagulant was subjected to second ripening according to gold and sulfur sensitization. After completion of the ripening, the emulsion was divided into portions of 1 kg. in weight, and the divided emulsions were individually incorporated witheach of such combinations of sensitizing -dyes as shown in Table 4. Each emulsion was allowed to stand with stirring at about 40C. for 20 minutes to sufficiently stabilize the color sensitization thereof, and then l-(3-carb0xyphenyl)-3-(4-stearoylaminophenyl)- S-pyrazolone as a magenta coupler was dispersed in the emulsion, which was then adjusted to pH 6.8 to prepare a green-sensitive reversal color photographic emulsion. This emulsion was coated on a film base and then dried to obtain a sample. The sample was exposed in the same manner as in Example I and then developed at 20C. for 10 minutes with a first developer of. the following composition:

Metol 2 g. Anhydrous sodium sulfite 60 g. Hydroquinone 5 g. Sodium carbonate (monohydrate) 50 g. Potassium bromide 8 g. Potassium thiocyanate 1.5 g.

, 1 liter Water to make After ordinary stopping, hardening and water-washing, the sample was subjected to second exposure by use of a white light and then developed at 20C. for 12 minutes with a color developer of the following composition:

N,N-Diethyl-p-phenyldiamine sulfate g. Anhydrous sodium sulfite 2 g. Sodium carbonate (monohydrate) 82 g. Potassium bromide I g. Water to make 7 l liter Subsequently, the color-developed sample-was subjected to ordinary stopping, fixing, water-washing and bleaching, washed with running water for 20 minutes and then dried.

The thus treated sample was subjected to sensitometry and measured in residual color to obtain the results as shown in Table 4. The relative speed in the table is a value calculated by assuming as 100 the relative speed in green sensitivity of the control sample used in Example 2.

TABLE 4 Rela- Fog Sample Amount of compound incorporated tive (residual No. per kg. of emulsion speed color) 21 Control dye (A) mg. I

Control dye (B) 5 mg. 100 0. l0 22 Compound (4) 7.5 mg.

Compound 7.5 mg. 130 0.07 23 Compound (2) 7.5 mg.

Compound (13) 7.5 mg. 140 0.08 24 Compound (5) 7.5 mg.

Compound (13) 7.5 mg. 120 0.07 25 Compound (4) 5 mg.

+ Compound (15) 5 mg. 140 0.08

Compound (17) 5 mg. 26 Compound 5) 3 mg.

+ Compound (13) 5 mg. 140 0.07

' Compound (16) 7 mg.

(In the table, the control dyes (A) and (B) were the same as those used in Example 2.)

As in clear from Table 4,.it is understood that the reversal color photographic green-sensitive materials of the present invention are more excellent in photographic properties than the control sample (21).

wherein R and R are individually a lower alkyl group which may be substituted by an alkoxy or hydroxyalkoxy group; R, and R are individually a lower alkyl group, a hydroxyalkyl group or a sulfoalkyl group; Y

and Y are individually a lower alkyl group which may zs u mtsqlzy, an al xy qthydxexya kex so p or an aryl group; X is an anion; and n is an integer of 1 or 2, with at least one compound represented by the general formula (II),

l oms.

-SO;H (HA-S03 (II) wherein R is a lower alkyl group; and A is an alkylene group, or a combination of said compounds with at least one compound represented by the general formula (Ill),

U1 A g -i i) {a (1-) II,

(X -m (III) ide and anhydro-S,5'-dichloro-3,3-di(sulphopropyl)- 9-ethyl-oxacarbocyanine hydroxide.

3. A light-sensitive silver halide photographic material as claimed in claim 1, wherein said combination is a supersensitizing combination consisting of anhydro- 5 ,5 '-di-(carboxy-n-butyl)-l ,l '-diethyl-3,3 I di(sulphopropyl)-benzimidazolo-carbocyanine hydroxide and anhydro-S ,5 -dichloro-3 ,3 -di(sulphobutyl)-9- methyl-oxacarbocyanine hydroxide.

4. A light-sensitive silver halide photographic material as claimed in claim 1, wherein said combination is a supersensitizing combination consisting of anhydro-3- ethyl-3 3-sulphopropyl)-l ,l -diethyl-5,5 '-di(carboxy-n-propyl)-benzimidazolo-carbocyanine hydroxide and anhydro-S ,5 -dichloro-3 ,3 -di(sulphoethyl)-9- ethyl-oxacarbocyanine hydroxide.

' 5. A light-sensitive silver halide photographic material as claimed in claim 1, wherein said combination is a supersensitizing combination consisting of anhydro- 5,5 '-di(carboxyphenyl)-1 ,l '-diethyl-3,3- di(sulphopropyl)-benzimidazolo-carbocyanine hydroxide and anhydro-S,5-dichloro-3,3'-di(sulphopropyl)- 9-ethyl-oxacarbocyanine hydroxide.

6. A light-sensitive silver halidephotographic material as claimed in claim 1, wherein said combination is a supersensitizing combination consisting of anhydro- 5 ,5 '-di(carboxy-n-butyl)-l,1'-diethyl-3 ,3 di(sulphopropyl)-benzimidazolo-carbocyanine hydroxide, anhydro-5,5-dichloro-3,3-di(sulphopropyl)-9- ethyl-oxacarbocyanine hydroxide and anhydro-3'- sulphobutyl-1'-methyl-selena-2'-cyanine hydroxide.

y-n-propyl)-benzimidazolo-carbocyanine hydroxide, anhydro-5,5'-dichloro-3,3'-di(sulphobutyl)-9-ethyloxacarbocyanine hydroxide and 3-carboxyethyl-l-ethyl- 6'-methyl-selena-2'-cyanine iodide.

9. A light-sensitive silver halide photographic material as claimed in claim 1, wherein said combination is a supersensitizing combination consisting of anhydro- 5,5 '-di(carboxy-n-butyl)-1,1'-diethyl-3,3'-di(hydroxyethyl)-benzimidazolo carbocyanine iodide and anhydro-5,5'-dichloro-3 sulphopropyl-3'-sulphobutyl-9 ethyl-oxacarbocyaninehydroxide.

Claims

1. A light-sensitive silver halide photographic material characterized by containing in the silver halide photographic emulsion layer thereof a combination of at least one compound represented by the general formula (I),

2. A light-sensitive silver halide photographic material as claimed in claim 1, wherein said combination is a supersensitizing combination consisting of anhydro-5,5''-di-(carboxy-n-butyl)-1,1''-diethyl-3,3''-di(sulphopropyl)-benzimidazolo-carbocyanine hydroxide and anhydro-5,5''-dichloro-3, 3''-di(sulphopropyl)-9-ethyl-oxacarbocyanine hydroxide.

3. A light-sensitive silver halide photographic material as claimed in claim 1, wherein said combination is a supersensitizing combination consisting of anhydro-5,5''-di-(carboxy-n-butyl)-1,1''-diethyl-3,3''-di(sulphopropyl)-benzimidazolo-carbocyanine hydroxide and anhydro-5,5''-dichloro-3, 3''-di(sulphobutyl)-9-methyl-oxacarbocyanine hydroxide.

4. A light-sensitive silver halide photographic material as claimed in claim 1, wherein said combination is a supersensitizing combination consisting of anhydro-3-ethyl-3''-(3-sulphopropyl)-1,1''-diethyl-5,5''-di(carboxy-n-propyl)-benzimidazolo-carbocyanine hydroxide and anhydro-5,5''-dichloro-3, 3''-di(sulphoethyl)-9-ethyl-oxacarbocyanine hydroxide.

5. A light-sensitive silver halide photographic material as claimed in claim 1, wherein said combination is a supersensitizing combination consisting of anhydro-5,5''-di(carboxyphenyl)-1,1''-diethyl-3,3''-di(sulphopropyl)-benzimidazolo-carbocyanine hydroxide and anhydro-5,5''-dichloro-3, 3''-di(sulphopropyl)-9-ethyl-oxacarbocyanine hydroxide.

6. A light-sensitive silver halide photographic material as claimed in claim 1, wherein said combination is a supersensitizing combination consisting of anhydro-5,5''-di(carboxy-n-butyl)-1,1''-diethyl-3,3''-di(sulphopropyl)-benzimidazolo-carbocyanine hydroxide, anhydro-5,5''-DICHLORO-3,3''-di(sulphopropyl)-9-ethyl-oxacarbocyanine hydroxide and anhydro-3''-sulphobutyl-1''-methyl-selena-2''-cyanine hydroxide.

7. A light-sensitive silver halide photographic material as claimed in claim 1, wherein said combination is a supersensitizing combination consisting of anhydro-5,5''-di(carboxy-n-butyl)-1,1''-diethyl-3,3''-di(sulphopropyl)-benzimidazolo-carbocyanine hydroxide, anhydro-5,5''-dichloro-3,3''-di(sulphopropyl)-9-ethyl-oxacarbocyanine hydroxide and 3-carboxymethyl-1''-ethyl thia-2''-cyanine iodide.

8. A light-sensitive silver halide photographic material as claimed in claim 1, wherein said combination is a supersensitizing combination consisting of anhydro-3-ethyl-3''-(3-sulphopropyl)-1,1''-diethyl-5,5''-di(carboxy-n-propyl)-benzimidazolo-carbocyanine hydroxide, anhydro-5,5''-dichloro-3,3''-di(sulphobutyl)-9-ethyloxacarbocyanine hydroxide and 3-carboxyethyl-1''-ethyl-6''-methyl-selena-2''-cyanine iodide.