US3649288A - Supersensitized silver halide photographic emulsion - Google Patents

Abstract

A supersensitized silver halide emulsion comprising a sensitizing dye of the general formula (I)

wherein R, R1, R2 and R3, which may be same or different, each represents a group of the alkyl series, i.e., an alkyl, a substituted alkyl, or an allyl aralkyl group; L represents a monomethyne group or aliphatic hydrocarbon chain which may combine with the N-atom in the heterocyclic ring containing Z1 to form a ring; R4 represents a hydrogen atom or an alkyl or an aryl group m, n and p each represents 1 or 2 and d represents 0, 1 or 2; X represents an anion and forms an intramolecular salt when p is 1; and Z and Z1, which may be same or different, each represents the nonmetallic atomic groups necessary to complete a 5- or 6-membered heterocyclic nucleus and a polycyclic aromatic sulfo compound of the general formula (II)DSO3M (II) wherein M represents a hydrogen atom or a cation forming a water-soluble salt of a compound represented by said formula (II), and D represents a polycyclic aromatic radical, is disclosed.

Description

United States Patent Shiha et al.

[45] Mar. 14, 1972 [54] SUPERSENSITIZED SILVER HALIDE PHOTOGRAPHIC EMULSION [72] Inventors: Keisuke Shiba; Masanao Hinata; Akira Sato; Hiroshi Misu, all of Kanagawa,

Japan [73] Assignee: Fuji Photo Film Co., Ltd., Kanagawa,

Japan [22] Filed: July21,1970

[2 1] Appl. No.: 56,959

[30] Foreign Application Priority Data July 21, 1969 Japan ..44/57545 [52] US. CL ..96/122, 96/114, 96/123 [51] Int. Cl. ..'.G03c 1/22, G03c 1/28 [58] Field ofSearch 1.96/122,l14,123

[56] References Cited UNITED STATES PATENTS 3,416,927 12/1968 Kalenda ..96/l22 Primary Examiner-Norman G. Torchin Assistant Examiner-Alfonso T. Suro Pico Attomey-Sughrue, Rothwell, Mion, Zinn and MacPeak [57] ABSTRACT A supersensitized silver halide emulsion comprising a sensitizing dye of the general formula [l] O 1J3 Il1 --Zi atom or an alkyl or an aryl group m, n and p each represents 7 1 or 2 and d represents 0, 1 or 2; X- represents an anion and forms an intramolecular salt when p is 1; and Z and Z which may be same or different, each represents the nonmetallic atomic groups necessary to complete a 5- or 6- membered heterocyclic nucleus and a polycyclic aromatic sulfo compound of the general formula [II] Ds a [In wherein M represents a hydrogen atom or a cation forming o uurm.ofi ..o oa water-soluble salt of a compound represented by said formula [II], and D represents a polycyclic aromatic radical, is disclosed.

SUPERSENSITIZED SILVER HALIDE PHOTOGRAPHIC wherein R, R,, R and R which may be same or different,

EMULSION each represents a group of the alkyl series, i.e., an alkyl, a substituted alkyl, or an allyl aralkyl group; L represents a BACKGROUND OF THE INVENTION monomethyne group or aliphatic hydrocarbon chain which Field Ofthe Invention 5 may combine with the N-atom in the heterocyclic ring con- This invention relates to a silver halide photographic emultammg 21 to form 3 R4 represents a hydrogen atom or an sion. More particularly, this invention relates to a so-called alkyl or an aryl group; n and P each rePresems l or 2 d supersensitized" silver halide photographic emulsion. represents 1 or 2; X Presents an amen and ffjrms an Description Ofthe Prior An tramolecular salt when p is l; and Z and 2,, which may be It is well known in the art ofthe manufacture ofsilver halide same or dlfferenn each represents the nonmetalhc atomlc photographic emulsions that the sensitive range of the spec- EYOUPS necessary to complete a or 'membered hetero trum of silver halide emulsion can be expanded, that is, the cycl'c nucleus" emulsion is spectrally sensitized by addition thereto of a sen- R and R3 m the general formula [I] a group m the sitizing dye or a Spectral Sensitizen alkyl series, for example, methyl, ethyl, propyl, B-hydrox- If a silver halide emulsion is more intensively sensitized, in yethyl' flacetoxyethyl Sulfoethyl( C2H4sO4 Carbox at least a portion of the spectral range sensitized by a senymethylifi'carboxyethyly'carboxypropylp'sulfoethyly'sul' sitizer, by the addition of the sensitizer in combination with fopmpyl, ssulfobutyl auyl benzyl' phenethyl pcarbox' another dye or organic compound the sensitization obtained ybenzyl and p'sulfophenethyl' by the addition of the sensitizer alone at the same combined R4 m the f formula [I] for example methyl ethyl concentration of the sensitizer and the other dye or organic phenyl or the pigment, then the silver halide emulsion is regarded as being a X general formula for example a chlonne.lon a supersensitized silver halide emulsion. The supersensitizabromme a Wrchlorate a p'Foluenesulfonate a tion Ofien causes a Shift in the Sensitization maximum. beneneksulfonate ion, an ethylsulfate ion, a methylsulfate ion ort e i e. SUMMARY OF E NVENTION The heterocyclic nucleus completed by the Z or Z in the general formula [I], for example, can be of the thiazole series, We have found that supersensitization is obtained by the ad such as thiazole itself and thiazoles having a substituent on its dition to a silver halide photographic emulsion ofa sensitizing ring such as methyl or phenyl; of the benzothiazole series, dye represented by the following general formula [l] such as benzothiazole itself and benzothiazoles having ring wherein R, R,, R and R which may be same or different, substituents such as, for example, a halogen atom, an alkyl, an each represents a group of the alkyl series, i.e., an alkyl, a subalkoxyl or a phenyl group; of the naphthothiazole series, such stituted alkyl, or an allyl aralkyl group; L represents a as a-naphthothiazole, B-naphthothiazole, monomethyne group or aliphatic hydrocarbon chain which tetrahydronaphthothiazoles and naphthothiazoles having on may combine with the N-atom in the heterocyclic ring coneither benzene ring substituents such as, for example, an altaining Z, to form a ring; R represents a hydrogen atom or an koxyl group; of the oxazole series such as substituted oxazoles alkyl or an aryl group; m, n andp each represents 1 or 2 and d having ring substituents such as, for example, an alkyl or a represents 0, l or 2; X represents an anion and forms an inphenyl group; of the benzoxazole series, such as benzoxazole tramolecular salt when p is l; and Z and 2,, which may be itself and benzoxazoles having ring substituents such as, for same or different, each represents the nonmetallic atomic 5 example, a halogen, a methyl, an ethyl, an ethoxy, a hydroxyl groups necessary to complete a 5- or 6-membered heteroor a phenyl group; of the naphthoxazole series such as acyclic nucleus, in combination with a polycyclic aromatic naphthoxazole and B-naphthoxazole; of the selenazole series, compound having at least one sulfo group in the molecule such as 4-methylselenazole and 4-phenylselenazole; of the represented by the following general formula [ll] benzoselenazole series, such as benzoselenazole itself, 5- DSO M [ll] chlorobenzoselenazole, S-methylbenzoselenazole, S-methoxwherein M represents a hydrogen atom or a cation forming a ybenzoselenazole and 5-hydroxybenzoselenazole; of the water-soluble salt of a compound represented by said formula naphthoselenazole series, such as a-naphthoselenazole and B- [ll], and D represents a polycyclic aromatic radical. The comna hthoselenazole; of the thiazoline series, such as thiazoline bination of the sensitizing dye of the general formula [I] and itself and 4-methylthiazoline; of the 2-quinoline series, such as the sulfo-group-containing polycyclic aromatic compound of quinoline itself and quinolines having on either benzene ring the general formula [II] results in a supersensitization when substituents such as, for example, a halogen, -a methyl, a tested in a conventional emulsion. methoxy or a hydroxyl (except for the 2-position) group; of the 4-quinoline series such as quinoline itself and 4-quinolines DETAXLED DESCRIPTION OF THE INVENTION having on either benzene ring substituents such as, for exam- 5 ple, methyl or methoxy (except for the 4-position) group; of As indicated above the sensitizing dye is one represented by the benzimidazole series, such as l,3-dimethylbenzimidazole, the following general formula [I] l,3-diethylbenzimidazole, l,3-cliethyl-5-chlorobenzimidazole,

l,3-diethyl-5,fi-dichlorobenzimidazole; of the 3,3'-dialkylindolene series, such as 3,3'-dimethylindolene, 3,3',5-trimethylindolene and 3,3',7-trimethylindolene; of the Z-pyridine series such as pyridine itself and pyridines having substituents such as, for example, a methyl group in other than the 2-position; and of the 4-pyridine series such as pyridine itself.

M in the general formula [I] is, for example, a sodium ion, a potassium ion, an ammonium ion, a triethanolammonium ion aNd a pyridinium ion.

The polycyclic aromatic compound having at least one sulfo group in the molecule used in combination with the sensitizing dye having the general formula [I] is of the general formula DSO;,M 111 wherein M represents a hydrogen atom or a cation forming a water-soluble salt of a compound represented by said formula [II], and D represents a polycyclic aromatic radical.

The term polycyclic aromatic radical as used in the general formula lll] is intended to encompass a residue of a compound containing at least one condensed aromatic nucleus, such as, for example, a naphthalene or a purene nucleus or a residue of at least two benzene nuclei or other aromatic nuclei, such as, of a triazine, or a purimidine nucleus which are combined directly with each other such as, for example, diphenyl, terphenyl or quaterphenyl or through an aliphatic chain, an atom or an atomic group with each other". Hereinafter, in this specification, the sulfo-group-containing polycyclic aromatic compound of the general formula [II] will be hereinafter designated as sulfo compound" for convenience.

Separate portions of the emulsion are sensitized with the spectral sensitizer represented by the general formula [I] (hereinafter dye) in a series of concentrations of the sensitizer, and to each is added the "sulfo compound" at various concentrations, for instance, concentrations of l, 5, l and 20 times the concentration of the dye. The so sensitized emulsions are separately applied to supports and dried. The photographic elements thus obtained are subjected to sensitometer testing for determination of the range and degree of spectral sensitivity of the emulsions.

If the sensitivity brought about by the combination of the dye and the sulfo compound exceeds, even if in a least a portion of the range of photosensitization, the sensitivity brought about by the dye alone at the same concentration of the combined concentration of the dye and the sulfo compound in the combination, this is the evidence for a supersensitization effect.

Especially useful sulfo compounds having the general formula [II] are those represented by the following general forwherein Y represents =CH or =N; R R R and R which may' be the same or different, each represents a hydrogen atom, a hydroxyl group, an alkoxyl group, a group of the aryloxyl series, for example, an aryloxyl group and a substituted aryloxyl group (for example, a phenoxy, an o-tolyloxy or a p-sulfophenoxy group), a halogen atom (for example, a chlorine or a bromine atom), a heterocyclic nuclear group (for example, a morphonyl or piperidyl group), an alkylthio group (for example, a methylthio or an ethylthio group), a heterocyclic thio group (for example, benzothiazylthio group), an arylthio group (for example, a phenylthio or a tolylthio group), an amino group, a group of the alkyl amino series, for example, an alkylamino and a substituted alkylamino group (for example, a methylamino, a dimethylamino, an ethylamino, a propylamino, a diethylamino, a dodecylamino, a cyclohexylamino, a B- hydroxyethylamino, a di-B-hydroxyethylamino or a B-sulfoethylamino group), a group of the aryl amino series, for example, an arylamino and a substituted arylarnino group (for example, an anilino, an o-sulfoanilino, a m-sulfoanilino, a psulfoanilino, an o-anisylamino, a p-anisylamino, a m- 5 anisylamino, an o-toluidino, a m-toluidino, a p-toluidino, an ocarboxyanilino, a m-carboxyanilino, a p-carboxyanilino, a hydroxyanilino, a naphthylamino or a sulfonaphthyl amino group), a heterocyclic amino group (for example, a 2- benzothiazolamino, a 2-pyridylamino group) and an aryl group (for example, a phenyl group); wherein A represents a bivalent radical selected from the group consisting of A,and --A wherein A, represents groups having the following formulas 5 03M S 03M and wherein A represents groups having the following formuwherein R and R which may be the same or different, each represents a group of the acylamino series (for example, an acetamido, a sulfobenzamido, a 4-methoxy-3-sulfobenzamido, a Z-ethoxybenzamido, a 2,4-diethoxybenzamido, a ptoluylamino, a 4-methyl-2-methoxybenzamido, a naphthoylamino, a Z-naphthoylamino, a 2,4-dimethoxybenzamido or a Z-thienylbenzamido group) or a sulfo group; and wherein R represents a hydrogen atom or a sulfo group, with at least one of the groups of R to R being a sulfo group.

The sensitizing dyes of the general formula [I] for use in accordance with the present invention are disclosed by F.M. Hamer in C yam'n Dyes and Related Compounds, Chapter 15, p. 671, Interscience Publishers 1964).

Some of the sulfo compounds of the general formula [III] for use in the present invention are disclosed in, for instance, U.S. Pat. No. 2,171,427; 2,660,587; 2,473,475 and 2,595,030.

The sensitizing dye of the general formula [I] for use in the present invention is a dye containing at least four heterocyclic rings in which two ketomethylene nuclei are directly bonded to each other. The sensitizing dye of the general formula [I] differs from dyes containing one ketomethylene nucleus in the center of the molecule and the two basic nuclei and from trinuclear dyes containing two ketomethylene nuclei, not only in chemical structure but also in the following characteristics.

1. The trinuclear dyes containing two ketomethylene nuclei in general have low solubilities in methanol, while the sensitizing dye represented by the general formula [I] has a high solubility in methanol or similar solvents.

2. The sensitizing dye represented by the general formula [I] incorporated in a silver halide photographic emulsion imparts thereto a sensitivity which is reduced only slightly by the addition of conventional additives for photographic emulsions such as, for example, color couplers, antifogging agents and irradiation inhibiting dyes.

3. The sensitizing dye represented by the general formula [I], when used alone, however, is generally inferior in sensitizing power to dyes. having one ketomethylene nucleus in the center of the molecule and two basic nuclei and needs another sensitizing technique to provide a highly sensitive emulsion. This additional sensitization is attained by the combination of the sensitizing dye represented by the general formula [I] with the sulfo compound.

The incorporation of the sulfo compound represented by the general formula [II] in combination with the sensitizer represented by the general formula [I] in a silver halide emulsion results in supersensitization, and, according to the circumstances, a marked reduction of fog in comparison with the incorporation of the sensitizer alone. Although some of the sensitizing dyes represented by the general formula [I] have disadvantages in that they cause a reduction of the sensitivity of emulsion during storage when incorporated in photosensitive materials, the reduction in sensitivity during storage can be minimized by incorporating into the emulsion the sensitizer in combination with a certain one of the sulfo compounds represented by the general formula [il].

The combination of the sensitizer of the general formula [I] and the sulfo compound of the general formula [II] has a super sensitization effect over a wide range of amounts added to a silver halide emulsion. The optimum amount of the sensitizer and of the sulfo compound to give the desired supersen sitization can be determined by conventional methods used in photographic emulsion techniques. The extent of the supersensitization can be determined by measuring the sensitivity using a spectral sensitometer.

It is preferred to use the sensitizer at a concentration of from 0.002 to 0.2 g./g.-mol of silver halide and the sulfo compound at a concentration of from 0.01 to l0.0 g./g.-rnol of silver halide in the silver halide emulsion. The preferred ratio of the concentration of the sensitizer to the concentration of the sulfo compound ranges from 1:1 to 1:200. Addition of the sensitizer to an emulsion can be performed in the conventional manner well known in the art. The sulfo compound can be added as a solution in water or in 21 methanol, ethanol or like organic solvent to a silver halide emulsion. It is convenient to add the sensitizer and the sulfo compound to the emulsion before application to a substrate. The sensitizer and the sulfo compound can be added to the emulsion in the order of the sensitizer and then the sulfo compound or, alternately, the sulfo compound and then the sensitizer or they can be added in admixture to the emulsion. The incorporation of the sensitizer and the sulfo compound can also be attained during ageing of the photosensitive element after washing with water.

In the preparation of the silver halide emulsion of the present invention, there can be used, in place of gelatin in a gelatin-silver halide emulsion, resinous materials and derivatives having no adverse effects on photosensitive materials.

In the preparation of the emulsions for use in the practice of the present invention silver chloride, silver bromide, silver iodobromide, silver chloroiodide, silver chloroiodobromide and similar silver halides can be used.

Chemical sensitizers, antifogging agents, stabilizers, hardeners, coating assistants, plasticizers, developing promoters, toners, fluorescent whitening agents, anti-airfogging agents, couplers and other conventional additives can be incorporated in the emulsion of the present invention. Dyes used in the silver-dye bleaching process as disclosed in Japanese Pat. specification No. 35/ 13093 can also be incorporated in the emulsion. The emulsion can be applied conventionally to a suitable support such as, for example, sheet glass, cellulose derivative films, synthetic resin films or baryta papers.

The sensitizer of the general formula [I] for use in the present invention is exemplified by the following specific examples but is not limited thereto.

The sulfo compounds of the general formula [II] for use in 11-4 the present invention are exemplified by the following com- N pounds but are not limited thereto. -l W 11-1 1 N N o Na Gyms C) The present invention is illustrated in greater detail by reference to the following examples but is not limited thereby.

EXAMPLES To separate portions of a silver halide emulsion from the same batch were added (1) a sensitizer represented by the general formula [I] or (2) a combination of a sensitizer represented by the general formula [I] and a sulfo compound represented by the general formula [ll]. Each of the separate emulsion portions thus sensitized was applied to an acetyl-cellulose base. The coated film was, after drying, exposed through a Fuji filter No. 7 (Trademark, transmitting light of wavelengths of 590 millimicrons or longer) or a Fuji filter No. 3 (Trademark, transmitting light of wavelengths of 480 millimicrons or longer) and subjected to development.

The value of the sensitivity is the relative value of the amount of exposure needed to give an optical density (including fog) of 0.l and was calculated by basing the relative sensitivity of an emulsion containing the sensitizer alone as 100.

The values obtained with emulsions containing a sulfo compound alone are not shown because little or no sensitization effect was obtained. Although within runs of the same example an emulsion of the same batch was used, in separate examples there were used the same or different emulsions. The results are summarized in Table l. In Examples 1 to 4 a silver chlorobromide emulsion of the same batch was used and in Examples 5 to 15 a silver iodobromide emulsion of the same batch was used. The specimens in Example 13 only were exposed through a Fuji filter No. 3. The specimens of Examples 1 to 4 were developed at 20 C. for 2 minutes with a developing solution as indicated in Table 2 and the specimens of Examples 5 to [5 were developed at 20 C. for 4 minutes in a developing solution as indicated in Table 3.

TABLE 2 8 1 100 0.11 11. 14 951 ll-4(968) 155 0.0a N-Methyl-p-aminophenol Sulfate 3.1 g Sodium S ulfite 45 g. 9 O' [4,861] 10 008 Hyimqmmne p. 1-5(s11.1 ll-4(968) 100 0.0a Sod1um Carbonate (anhydrous) 67.5 g 5 Potassium Bromide l.9 g. q. l-6(70.3) 100 0.08 Diluted with water to l l. r. l-6( 70.3) ll-4(968) 132 0.08

11 5'. l-7(87.3) 100 00s 10 1'. l-7(87.3) ll-4(968) 110 0.0a TABLE-3 12 11'. 141 1315 100 7 0. 12 v. l-8(8l.5) ll-4(968) 204 0.09

13 w. 1 3 74.0 100 0.0a N-Methyl-p-ammophenol Sulfate 2.2 g. X| I 9(74.0) 4(968) 145 008 Sodium Sulfile 96 g. Hydroquinone 8.8 g Sodium Carbonate 48 g. l4 y l-l0(84.6) I00 0.10 Potassium Bromide 5 g. z l-l0(84.6) 11-4 968) 170 0.09 Diluted with water 10 l l.

15 a". 141 51.9 100 0.10 b". 141 51.9 11-4 9ss 145 0.09

Additives (mg) l/ Milligrams ofadditive er gram mole ofsilvcr halide.

Exam H What is claimed is: No. Sensltlzmg Dye Sulfo Sensmvny Fog Compound 1. photograph1c s1lver hahde emuls1on sens1t1zed with a comb1r1at1on of l 8' 14,9 100 M7 1. at least one sens1t1z1ng dye havmg the followmg general formula 0 Ilia (H) I'M l Z R; N CN z, i l l l l 1 1 1+ RN(-CH=CH)ur-C =CHC d=C\ )m-1= 1( ')p-1 s s [I] 4(95 l) 195 M7 wherein R, R,, R and R;,, which may be the same or different, c. 141951) ll-Zt968) 186 0.07 each is selected from the group consisting of a group of the 3' figs- 13112323; :88 8-3; alkyl series; R is selected from the group consisting of a Mwi'l) I hydrogen atom, an alkyl group and an aryl group; wherein Z 1-4 95.1 ll-6(968) 155 0.05 and 2,, whlch ma be the same or d1fferent, each 15 the nong Y 14(951) 145 metall1c atom1c groups necessary to complete a heterocyclic 0 nucleus selected from the group consisting of the thiazole se- 3 ries, benzothiazole series, naphthothiazole series, oxazole sel-l(46.0) ll-8t968) 152 0.07 b 1 h h l l l Hugo) "8068) m r1 es, enzoxazo e senes, nap t oxazo e ser1es, se enazo ese- 1. l-l(46.0) Ill0(968) 126 0.07 r1es, benzoselenazole series, naphthoselenazole serles, Hi4) (968) thiazoline series, 2-quinoline series, 4-quinoline series, n. l-l(46.0) ll-l2(968) 141 0.07 0 o) W06) 35 o 07 benz1m1dazole series, 3,3 -d1alkyl1ndolene1ne ser1es, 2- p. l-l(46.0) 11-14(968) 135 0.07. pyridine series, 4-pyridine series; wherein L is selected from the group consisting of a monomethine group and an ahphatic 3 q 1-2 4s.3 carbon chain which may combine with the N-atoms in said r -2 11-151484) 0.07 50 heterocyclic nucleus contaming 2 to form a ring; wherem m, s l2(48.3) ll-l6(484) 120 0.07

and wherem d is 0 l or 2 and wherem 1 l-2(48.3) 11-17 s4s I26 007 n andpeach 1 F u 1-2 4s 3 ll-l8(484) 132 0.07 X represents an anion, and v l-2(48.3) "-191484) 0.07 2. at least one sulfo compound havmg the following general w l2(43.3) ii-ZO(484) I32 0.07 formula x l-2(48.3) 11-21mm) 152 0.007 D SO3M wherein D is a polycyclic aromatic radical, said radical being 4 32231; 1 "42968) :22 8'3: selected from the group consisting of the residue of a com- HMO], "43968, 209 0,07 pound containing at least one condensed aromatic nucleus, at 15'. 14 40.7) Il-25(968) 186 0.0a least two benzene nuclei, and more than two aromat1c nuclel; "46663) O and M is selected from the group consisting of a hydrogen (40], lmows) I66 t d t' f wat r soluble salt of said sulfo e. 1-s 40.7 ll35(968) 120 0.09 a om a ca ormmg a e r: 1 3 40.7 11-36(968) 120 0.09 P

2. The photographic silver halide emulsion of claim 1, sen- 5 921 100 sitized with a combination of at least one sensitizing dye havh. 1-1 2.l) ll-4(968) 15 0. 65 ing the general formula 1 Pi --z R4 N C---N "z. 1 1 b t i a I -GH=CH).. 1-C =CH-C .1: =Lc =oHCH m ,=NR, x),, 1

- r s s [I] s i. I-2(96.7) 100 0.10

j. l-2(96.7) ll-4(968) 132 0.09

wherem R, R R R R,, Z, Z,, L, X, m, r1, d and p are as 7 H070) 100 M0 described in claim 1 and at least one compound having the fol- 1'. 14 97.0 ll-4(968) 112 0.08 75 lowing general formula wherein Y is selected from the group consisting of CH- and N-; wherein R R R,- and R which may be the 10 8 03M soar OgM S 03M (DH-@NHCO r s 03M and said A2 being selected from the group consisting of and wherein when A- is A,, at least one of R R R and R, has a substituent containing an -S0 M group;

3. The photographic silver halide emulsion of claim 1, sensitized with a combination of at least one sensitizing dye hav ing the general formula wherein R, R R R R Z, Z L, X, m, n, d and p are as described in claim 1 and at least one compound having the general formula wherein R and R which may be the same or different, each is selected from the group consisting of a group of acylamino series and a sulfo group; wherein R is selected from the group consisting of a hydrogen atom and a sulfo group, wherein at least one of R R and R is a sulfo group.

4. The photographic silver halide emulsion as claimed in claim 1, wherein the group of the alkyl series is selected from the group consisting of an alkyl group, a hydroxy alkyl group, an acetoxy alkyl group, a sulfatoalkyl group, a carboxy alkyl group, a sulfoalkyl group, an ally] group, a benzyl group, a phenethyl group, a carboxybenzyl group, and a sulfophenethyl group.

5. The photographic silver halide emulsion as claimed in claim 2, wherein said substituted aryloxyl group is selected from the group consisting of phenoxy, tolyloxy, and sulfophenoxy; wherein said group of the alkyl amino series is selected from the group consisting of an alkyl amino, hydroxyalkyl amino and a sulfoalkyl amino group; wherein the group of the arylamino series is selected from the group consisting of an anilino group, a sulfoanilino group, an anisylamino group, a toluidino group, a carboxyanilino group, a hydroxy anilino group, a naphthylamino group and a sulfonaphthylamino group, wherein the heterocyclic nuclear group is selected from the group consisting of a morphonyl and a piperidyl group; wherein the heterocyclic thio group is a benzothiazylthio group; wherein the heterocyclic amino group is selected from the group consisting of a benzothiazolamino group and a pyridylamino group.

6. The photographic silver halide emulsion as claimed in claim 3 wherein the group of the acylamino series is selected from the group consisting of an acetamido group, a sulfobenzamido group, an alkoxysulfobenzamido group, an alkoxybenzamido group, a toluylamino group, an alkylalkoxybenzamido group, a dialkoxybenzamido group, a naphthoylamino group and a thienylbenzamido group.

7. A photographic silver halide emulsion sensitized with a combination of and 8. A photographic silver halide emulsion sensitized with a 10. A photographic silver halide emulsion sensitized with a combination of 9. A photographic silver halide emulsion sensitized with a combination of l :0H 0 l 7 s s g CzHs I HQCHZOH and A N @M NH/ l N N $03M SO Na N N 11. A photographic silver halide mulsion n itiz d i h a 13. The photographic silver halide emulsion as claimed in combination of claim 1, wherein the sulfo compound is present at a level ranging from 0.01 to 10.0 grams per gram mol of silver halide.

02115 O 02115 S l l l l S --N N l l l l C=CHCH=C\ /O:C\ /C=CHC N I 6 115 C fif'l'he photographic silver halide emulsion as claimed in claim 12, wherein the weight ratio of said sensitizing dye to the sulfo compound in the emulsion ranges from 1:1 to 1:200.

15. The photographic silver halide emulsion as claimed in 2 claim 13, wherein the weight ratio of said sensitizing dye to the and 0 N N 0 FHN- 0H=crr NH-l Yo-fii J i N S O3Na S OaNB V V 5G3 LQ sulfo compound in the emulsion ranges from 1:1 to 1:200. 12. The photographic silver halide emulsion as claimed in 16 A photographic light-sensitive element comprising a claim 1, wherein the sensitizing dye is present at a level rangsupport having thereon at least one layer containing the ing from 0.002 to 0.02 grams per gram mol of the silver halide. photographic emulsion as claimed in claim 1.

Claims (16)

1. 2. at least one sulfo compound having the following general formula D-SO3M wherein D is a polycyclic aromatic radical, said radical being selected from the group consisting of the residue of a compound containing at least one condensed aromatic nucleus, at least two benzene nuclei, and more than two aromatic nuclei; and M is selected from the group consisting of a hydrogen atom and a cation forming a water-soluble salt of said sulfo compound.
2. 2. The photographic silver halide emulsion of claim 1, sensitized with a combination of at least one sensitizing dye having the general formula
3. 3. The photographic silver halide emulsion of claim 1, sensitized with a combination of at least one sensitizing dye having the general formula
4. 4. The photographic silver halide emulsion as claimed in claim 1, wherein the group of the alkyl series is selected from the group consisting of an alkyl group, a hydroxy alkyl group, an acetoxy alkyl group, a sulfatoalkyl group, a carboxy alkyl group, a sulfoalkyl group, an allyl group, a benzyl group, a phenethyl group, a carboxybenzyl group, and a sulfophenethyl group.
5. 5. The photographic silver halide emulsion as claimed in claim 2, wherein said substituted aryloxyl group is selected from the group consisting of phenoxy, tolyloxy, and sulfophenoxy; wherein said group of the alkyl amino series is selected from the group consisting of an alkyl amino, hydroxyalkyl amino and a sulfoalkyl amino group; wherein the group of the arylamino series is selected from the group consisting of an anilino group, a sulfoanilino group, an anisylamino group, a toluidino group, a carboxyanilino group, a hydroxy anilino group, a naphthylamino group and a sulfonaphthylamino group, wherein the heterocyclic nuclear group is selected from the group consisting of a morphonyl and a piperidyl group; wherein the heterocyclic thio group is a benzothiazylthio group; wherein the heterocyclic amino group is selected from the group consisting of a benzothiazolamino group and a pyridylamino group.
6. 6. The photographic silver halide emulsion as claimed in claim 3 wherein the group of the acylamino series is selected from the group consisting of an acetamido group, a sulfobenzamido group, an alkoxysulfobenzamido group, an alkoxybenzamido group, a toluylamino group, an alkylalkoxybenzamido group, a dialkoxybenzamido group, a naphthoylamino group and a thienylbenzamido group.
7. 7. A photographic silver halide emulsion sensitized with a combination of
8. 8. A photographic silver halide emulsion sensitized with a combination of
9. 9. A photographic silver halide emulsion sensitized with a combination of
10. 10. A photographic silver halide emulsion sensitized with a combination of
11. 11. A photographic silver halide emulsion sensitized with a combination of
12. 12. The photographic silver halide emulsion as claimed in claim 1, wherein the sensitizing dye is present at a level ranging from 0.002 to 0.02 grams per gram mol of the silver halide.
13. 13. The photographic silver halide emulsion as claimed in claim 1, wherein the sulfo compound is present at a level ranging from 0.01 to 10.0 grams per gram mol of silver halide.
14. 14. The photographic silver halide emulsion as claimed in claim 12, wherein the weight ratio of sAid sensitizing dye to the sulfo compound in the emulsion ranges from 1:1 to 1:200.
15. 15. The photographic silver halide emulsion as claimed in claim 13, wherein the weight ratio of said sensitizing dye to the sulfo compound in the emulsion ranges from 1:1 to 1:200.
16. 16. A photographic light-sensitive element comprising a support having thereon at least one layer containing the photographic emulsion as claimed in claim 1.