CA1115584A - Light-sensitive silver halide photographic material containing a tetrazolium compound and a sensitizing dye - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE:
A light-sensitive silver halide photographic material to be treated with a hydroquinones-containing developing solution. This material comprises a support and at least one hydrophilic colloidal layer coated thereon which contains silver halide grains having an average grain size of 0.05 to 1.5 µ, a tetrazolium compound and a sensitizing dye.

Description

The present invention relates to a novel light-sensitive silver halide photographic material and the processing method therefor. Particularly, it relates to a novel lith type ligh-t-sensitive silver halide photographic material for obtaining a photographic image with an especially high contrast, high sharpness and high resolving power, and to the processlng method therefor.
More particularly, it relates to a novel light-sensitive silver halide photographic material which is applicable advantageously to a light-sensitive silver halide photographic ``
material with a high contrast suitable for forming a dot- or line-image on a lith (printing) light-sensitive silver halide material or a copying light-sensitive material, as well as to the processing method therefor.
It has been known to form a photographic image with an extremely high contrast by using some kind of a light-sensitive silver halide photographic material.
It has been known, for example, to obtain a high contrast image, e.g. a line- or do-t-image by treating, with an alkaline hydroquinones developing solution containing sulfite ions in a very low concentration, a light-sensitive-material which comprises a silver halide emulsion containing silver chlo-ride in a high content (at least more than 50 mole %) and further containing silver iodide less than 5 mole ~, the grains of which emulsion being minute ~average grain size; ca. 0.3 ~), uniform in size and shape, and the grain size distribution thereof being narrow. The above-mentioned kind of light-sensitive silver halide material is known as the lith type light-sensitive material.
In printing, there is usually required such a process as to convert a con~inuous gradation original to a dot image;

- 2 -that is a process to convert the densities of the continuous gradation to a predetermined numbered assembly of dots respec-tively having areas o~ the same densities but proportional in size to the densities of the continuous gradation. In order to carry out this, the lith type light-sensitive material is subjected to development, after photographing the original image through a cross- or contact-screen, to form the dot image on the light-sensitive material.
For this purpose there has been employed a light-sensitive silver halide photographic material containing a silver halide emulsion, the grains of which being minute and being uni-form in size and shape. Even when this kind of a light-sensitive silver halide photographic material is employed, the intermediate density region (undesirable continuous gradation parts) is reproduced, beside the maximum density region and the minimum one (fog), when the material is processed with a standard black and white developing solution. The intermediate densit~v reyion or the so-called flinge, undesirable for producing a printing plate and makes the dot qualit~ worse.
There has heretofore been employed the lith type light-sensitive material also for the reproduction of a line image.
For the same reason, however, there have been obtained images having at best the ~-value of 5 - 6 of the characteristic curve, which value is lower than 7 - 9 required for forming the desirable line-image, if the standard black and white developincJ solution is employed. In order to avoid this, there has been employed, as mentioned above, a specific developing solution called " infec-tious developing solution." It is indispensablel however, to maintain the sulfite concentration in the infectious developing solution as low as possible to obtain a high con-trast image, but such the developing solution is very poor in storability because of the low concentration o~ the sul~ite so that this have caused a big trouble in printing business. Every effort has been made, however, to improve the storability. Nevertheless, such efforts have not been so successful. As a result, an ordinary developing solution for a continuous gradation, such as Metol/hydroquinone or phenidone/hydroquinone developing solution which is excellent in the storability, is recommended for processing the light-sensitive materials. However there has been known no method capable of obtaining a dot image with a good dot quality, by using such the developing solution.
It is, therefore, the primary object of the invention to provide a novel light-sensitive silver halide photographic material and the processing method thereof to obtain a high contrast silver image.
It is another object of the invention to provide a lith type light-sensitive silver halide material ~eing dye-sensitized and having a great development stability containing a tetrazolium compound suitable for obtaining a dot- or line-image.
It is still another object of the invention to provide a novel processing method of the above-mentioned lith type light-sensitive silver halide material to obtain a high contrast black and silver image, especially a dot- or line-image.
The inventors have found, after extensive studies to attain the above-mentioned objects, that the object can be attained by processing a lith type light-sensitive silver halide photo-graphic material containing, in a hydrophilic colloidal layer silver halide grains having a narrow grain size distribution, a tetrazolium compound and a sensitizing dye, after exposure, with a developing solution containing a hydro~uinones developing agent as a maln developing agent.
In accordance with the invention, there can be formed a superior line- or dot-image~ without employing the infectious development, by processing a light-sensitive silver halide photographic material having (coated on a support, at least one hydrophilic colloidal layer which comprises light-sensitive silver halide grains having an average grain size of 0.05 - 1.5 and at least 75~ of the total grains being within a range of 0.6 - 1.4 times iarger than the average grain size) a tetrazolium compound and a sensitizing dye, after the image exposure, with a hydroquinones-containing developing solution.
According to a preferred embodiment of the invention, there is obtained a high contrast silver image with a development stability and a superior reproducibility of the line image by processing a light-sensitive silver halide pho-tographic material containing silver halide grains having the above-mentioned grain size and the distribution thereof (hereinafter referred to as the silver halide of the invention), a diffusible tetrazolium compound and a sensitizing dye, after the image exposure, with a hydro-quinones-containing developing solution.
According to another preferred embodiment of the invention, there is obtained a dot-image ~half tone image) with a superior development stability and a superior dot quality by developing a light-sensitive silver halide photographic material containing the silver halide of the invention and a non-diffusible tetrazolium compound and a sensitizing dye, after the image exposure through a contact screen, with the Metol/hydroquinone developing solution (hereinafter referred to as the MQ developing solution) or with the phenidone-hydroquinone developing solution (hereinafter referred to as the PQ developing solution) which are .. i .

famous and polular for the black and white developing solution.
It can not be expected fxom heretofore known techniques that the high contrast line- or dot-image could be obtained without employing -the infectious developing solution.
As explained above, the tetrazolium compounds include non-diffusible and diffusi~le ones. The term "non-diffusible tetrazolium compound" means a compound which does not dissolve from the light-sensitive material to the developing solution during the development. In other words, the compound does not dissolve in a concentration of several ~, preferably not more than 2%, when a yelatin layer containing the compound is dipped for 10 minutes in an aqueous solution at 20 - 40C having the same ion strength and pH-value as those of the developing solution.
The representative tetrazolium compounds employed in the invention include the following compounds repres~nted by the general formulae:

R~ N R3 ( )n-l N~ c~N (I) _ R2 _ R4- ~ - N - D I 1l 5 2 (~) n-l N~C~ ~C~ (II) R8_ ~ _ I Rg R10-NI 1l Rll 2 (~) n-l C~ ~C/ (III) E t In the above formulae, Rl, R3, R4, R5, 8' 9 10 and Rll each represent a group selected from an aryl group such as a phenyl group (e.g. phenyl, tolyl, hydroxyphenyl, carboxyphenyl, aminophenyl or mercaptophenyl, carboxyethyl, nitrophenyl, ethoxyphenyl, iodophenyl, methoxyphenyl, cyano-phenyl, acetoamidophenyl, etc.), a naphtyl group (e.g. an ~-naphtyl, ~-naphtyl, hydroxynaphthyl, carboxynaphthyl or amino-naphthyl, etc.); and a heterocyclic group (e.g. a thiadiazolyl, benzothiadiazolyl, oxazolyl, pyrimidinyl or pyridyl group, 2,5-dimethyl thiazolyl, etc.); the groups can advantageously containan electron sharing group capable of forming a metal chelate or a complex such as primary, secondary, tertiary amino, oxime, thioether, keto, thioketo, hydroxyl, mercapto, carboxyl, sulfo, phospho, and al~oxyl; R2, R6 and R7 represent each a group selected from an aryl group such as a phenyl group and a naphthyl group, a heterocyclic group, an alkyl group (e.g. methyl, ethyl, propyl, butyl, mercaptomethyl or mercaptoethyl and a carboxyalkyl group such as methoxycarbonyl or ethoxycarbonyl), hydroxyl, carboxyl or the salt thereof, an amino group (e.g. amino, e`thyl-amino or anilino), mercapto, nitro and hydrogeni D represents adivalent aromatic group; E represents a group sele~te~ from an alkylene group, an arylene group and an aralkylene group; X is anion; and n is 1 or 2, provided that the compound forms an intra-molecular salt when n is 1.
In the above formula, the divalent aromatic group for E
is preferably an arylene group (e.g. phenylene, alkoxy-substituted phenylene such as methoxy-substituted phenylene, naphtylene diphenylene, etc.) or a divalent aromatic heterocyclic group. ;~
The following are typical examples oE the cationic moieties of the tetra~olium compounds represented by the formula but not intended to limit the tetrazolium compound thereof.
(1) 2-(Benzothiazol-2-yl)-3-phenyl-5-dodecyl-2H-tetrazolium (2) 2,3-Diphenyl-5-(4-t-octyl~xyphenyl)-2H-tetrazolium

(3) 2,3,5-Triphenyl-2EI-tetrazolium

(4) 2,3,5-Tri(p-carboxyethylphenyl)-2II--tetrazolium t5) 2-(Benzothiazol-2-yl)-3-phenyl-5-(o-chlorophenyl)-2H-tetrazolium (6) 2,3-Diphenyl-2H-tetrazolium (7) 2,3-Diphenyl-5-methyl-2H-tetrazolium :
(8) 3-(p-Hydroxyphenyl)-5-methyl-2-phenyl-2H-tetrazolium (9) 2,3-Diphenyl-5-ethyl-2H-tetrazolium (10) 2,3-Diphenyl-5-n-hexyl-2H-tetrazolium (11) 5-Cyano-2,3-diphenyl-2H-tetrazolium (12) 2-(genzothiazol-2-yl)-5-phenyl-3-(4-tolyl)-2H-tetrazolium (13) 2-(Benzothiazol-2-yl)-5-(4-chlorophenyl)-3-(4-nitrophenyl) 2H-tetrazolium (14) 5-Ethoxycarbonyl-2,3-di(3-nitrophenyl)-2H-tetrazolium (15) 5-Acetyl-2,3-di(p-ethoxyphenyl)-2H-tetrazolium (16) 2,5-Diphenyl-3-(p-tolyl)-2H-tetrazolium (17) 2,5-Diphenyl-3-(p-iodophenyl)-2H-tetrazolium (18) 2,3-Diphenyl-5-(p-diphenyl)-2H-tetrazolium~
(19) 5-(p-Bromophenyl)-2-phenyl-3-(2,4,6-trichlorophenyl)-2H-tetrazolium (20) 3-(p-Hydroxyphenyl)-5-(p-nitrophenyl)-2-phenyl-21I-tetrazolium (21) 5-(3,4-Dimethoxyphenyl)-3-(2-ethoxyphenyl)-2-(4-methoxy-phenyl)-2H-tetrazolium (22) 5-(4-Cyanophenyl)-2,3-diphenyl-2H-tetrazolium ~23) 3-(p-Acetamidophenyl)-2,5-diphenyl-2H-tetrazolium t24) 5-~cetyl-2,3-diphenyl-2H-tetrazolium (25) 5-(Fur-2-yl)-2,3-diphenyl-2EI-tetrazolium ~26) 5-(Thien-2-yl)-2,3-diphenyl-2H-tetrazolium t27) 2,3-Diphenyl-5-(pyrid-4-yl)-2H-tetrazolium (28) 2,3-Diphenyl-5-(quinol-2-yl)-2EI-tetrazolium (29) 2,3-Diphenyl-5-(benzoxazol-2-yl)-2I~-tetrazollum (30) 2,3-Diphenyl-5-nitro-2H-tetrazolium ~31) 2,2',3,3'-Tetraphenyl-5,5'-1,4-butylene-d.i-(2H-tetrazolium) (32) 2,2',3,3'-Tetraphenyl-5,5'-p-phenylene-di-(2~-tetrazolium) (33) 2-(~,5-Dimethylthiazol-2-yl)-3,5-diphenyl-2EI-tetrazolium (34) 3,5-Diphenyl-2-(triazin-2-yl)-2H-tetrazolium ~35) 2-(Benzothiazol-2-yl)-3-(4-methoxyphenyl)-5-phenyl-2H-tetrazolium (36) 2,5-Diphenyl-3-~-naphthyl-2H-tetrazolium (37) 3,3'-(3,3'-Dimethoxy-4,~'-diphenylene)-2,2',5,5'-tetraphenyl-di-(2H-tetrazolium) As the anion moiety, there can be mentioned, e.g. a : halogen ion, a thiosulfate anion, a su.lfate anion, a thiocyanate anion, an alkylsulfate anion, a nitrate anion, an acetate anion, a lower alkyl benzenesulfonate anion for the diffusible tetra~
zolium compound and higher alkylbenzene-sulEonate anion such as p-dodecylbenzenesulfonate anion, a higher alkylsulfate anion such as laurylsulfate anion, a dialkylsulfosuccinate anion such as di~2-ethylhexylsulfosuccinate anion, a polyether alcohol sulfate anion such as cetylpolyethenoxysulfate anion, a higher fatty acid anion such as stearic acid anion, and a polymer having :
acid radicals such as polyacrylate anion for the non-diffusible tetraozlium compound.
Most typical examples of the compounds of the invention are as follow:

._ g _ ~5~ ~

1] Diffusible tetrazolium compound (1) 2,3,5-Triphenyl-2H-tetrazolium chloride (2) 2,3,5-Tri(p-carboxyethylph~nyl)-2II-tetrazoliu~ iodide (3) 2-(Benzothiazol-2-yl)-3-phenyl-S-(o-chlorophenyl)-211-tetrazolium bromide (4) 2,3-Diphenyl-2H-tetrazolium thiosulfate

(5) 2,3-Diphenyl-5-methyl-2H-tetrazolium chloride

(6) 3~(p-Hydroxyphenyl)-5-methyl-2-phenyl-2H--tetrazolium sulfate 10 (7) 2,3-Diphenyl-5-ethyl-2~ tetrazolium chloride ~8) 2,3-Diphenyl-S n-hexyl-2EI-tetrazolium chloride (9) 5-Cyano-2,3-diphenyl-2H-tetrazolium thiocyanate (10) 2-(Benzothiazol-2-yl)-5-phenyl-3-(4-tolyl)-2~1-tetrazolium chloride (11) 2-(Benzothiazol-2-yl)-5-(4-chlorophenyl)-3-(4-nitrophenyl)-2H-tetrazolium chloride (12) 5-Ethoxycarbonyl-2,3-di(3-nitrophenyl)-2EI-tetrazolium bromide (13) 5-Acetyl-2,3-di(p-ethoxyphenyl)-2H-tetrazolium chloride 20 (14) 2,5-Diphenyl-3-(p-tolyl)-2H-tetrazolium methylsulfate (15) 2,5-Diphenyl-3-(p-iodophenyl)-2EI-tetrazolium chlorlde (16) 2,3-Diphenyl-5-(p-diphenyl)-2H-tetrazolium chloride (17) 5-(p-Bromophenyl)-2-phenyl-3-(2,~,6-trichlorophenyl)-2H-te-trazolium chloride (18) 3-(p-Hydroxyphenyl)-5-methyl-2-phenyl-2H-tetrazolium chloride (19) 5-(3,4-Dimethoxyphenyl)-3-(2-ethoxyphenyl)-2-(4-methoxy-phenyl)-2H-tetrazolium chloride (20) 5-(4~Cyanophenyl)-2,3-diphenyl-2I-I-tetrazolium chloride 30 (21) 3-(p-Acetamidophenyl)-2,5-diphenyl-2H--tetrazolium chloride 5~

(22) 5-Acetyl-2,3-diphenyl-2H-tetrazolium chloride (23) 5-(Fur 2-yl)-2,3-diphenyl-2H-tetrazolium chloride (24) 5-(Thien-2-yl)-2J3-diphenyl-2H-tetrazolium chloride (25) 2,3-Diphenyl-5-(pyrid-~-yl)-2~I-tetrazolium nitrate (26) 2,3-Diphenyl-5-(quinol-2-yl)-2H-tetrazolium chloride (27) 2,3-Diphenyl-5 (benzoxazol-2-yl)-2H-tetrazolium chloride (28) 2,3-Diphenyl-5-nitro-2H-tetrazolium methylsulfate (29) 2,2',3,3'-Tetraphenyl-5,5'-1,4-butylene-di-(2H-tetrazolium chloride) ~ :-(30) 2,2',3,3'-~etraphenyl-5,5'-p-phenylene di-(2H-tetrazolium ;
chloride) (31) 2-(4,5-Dimethylthiazol-2-yl)-3,5-diphenyl-2H-tetrazolium chloride (32) 3,5-Diphenyl-2-(triazin-2-yl)-2H-tetrazolium sulfate (33) 2-(Benzothiazol-2-yl)-3-(4-methoxyphenyl)-5-phenyl-2H-tetrazolium chloride (34) 2,5-Diphenyl-3-~-napthyl-2H-tetrazolium chloride (35) 3,3'-(3,3'-Dimethoxy-4,4'-diphenylene)-2,2',5,5'- ;~
tetraphenyl-di-(2H-tetrazolium chloride) (36) 5-(3-Methoxyphenyl)-3-(3-trif1.uoromethylphenyl)-2-phenyl-2~-tetrazolium acetate --[2] Non diffusible tetrazolium compound (37) 2-(Benzothiazol-2-yl)-3-phenyl-5-dodecyl-2H-tetrazolium bromide (38) 2,3-Diphenyl-5-(4-t-octyloxyphenyl)-2H-tetrazolium chloride (39) 2,3,5-Triphenyl-2H-tetrazolium diethylhexylsuccinate sulfonate (40) 2,3,5-Tri(p-carboxyethylphenyl)-2H-tetrazolium p-dodecyl-benzenesulEonate $

(413 2-(Benzothiazol-2-yl)-3-phenyl-5-(o-chlorophenyl)-2H-tetrazolium diethylhexylsuccinate sulfonate (42) 2,3-Diphenyl-2H-tetrazolium p-octylbenzenesulfonate (43) 2,3-Diphenyl-5-methyl-211-tetrazolium l`aurylsulfate (44) 3-(p-Hydroxyphenyl)-5-methyl-2-phenyl-2H-tetrazolium isopropylnaphthalenesulfonate (45) 2,3-Diphenyl-5-ethyl-2H-tetrazolium diethylhexylsulfo-succinate (46) 2,3-Diphenyl-5-n-hexyl-2H-tetrazolium cetylpolyethenoxy-sulfate (47) 5-Cyano-2,3-diphenyl-2H-tetrazolium polyacrylate (48) 2-(Benzothiazol-2-yl)-5-phenyl-3-(4-tolyl)-2H-tetrazolium diethylhexylsuccinate sulfonate (49) 2-(Benzothiazol-2-yl)-5-(4-chlorophenyl)-3-(~-nitrophenyl)-2H-tetrazolium diethylhexylsuccinate sulfonate (50) 5-Ethoxycarbonyl-2,3-di(3-nitrophenyl)-2H-tetrazolium diethylhexylsuccinate sulfonate (51) 5-Acetyl-2,3-di(p-ethoxyphenyl)-2H-tetrazolium die~hyl-hexylsuccinate sulfonate (52) 2,5-Diphenyl-3-(p-tolyl)-2H-tetrazolium p-octylbenzene sulfonate --(533 2,5-Diphenyl-3-(p-iodophenyl)-2H-tetrazolium p-octyl-benzenesulfonate `
(54) 2,3-Diphenyl-5-(p-diphenyl)-2~1-tetrazolium p-octyl-benzenesulfonate (55) 5-(p-Bromophenyl)-2-phenyl-3-(2,4,6-trichlorophenyl)-2H-tetrazolium isopropylnaphthalenesulfonate (56) 3-(p-Hydxoxyphenyl)-5-(p-nitrophenyl)-2-phenyl-2H-tetrazolium diethylhexylsuccinate sulfonate (57) 5-(3,4-Dimethoxyphenyl)-3-(2 ethoxyphenyl)-2-(4-methoxy-phenyl)-2H-tetrazolium diethylhexylsuccinate sulfonate (58) 5-(4-Cyanophenyl)-2,3-diphenyl-2H-tetrazolium diethyl-hexylsuccinate sulfonate (S9) 3-(p-Acetamidophenyl)-2,5-diphenyl-2H-tetrazolium laurylsulfate (60) 5-Acetyl-2,3-diphenyl-2H-tetrazolium diethylhexyl- -succinate sulfonate (61) 5-(Fur-2-yl)-2,3-diphenyl-2H-tetrazolium diethylhexyl-succinate sulfonate :
(62) 5-(Thien-2-yl)-2,3-diphenyl-2H-tetrazolium diethylhexyl-succinate sulfonate (63) 2,3-Diphenyl-5-(pyrid-4-yl)-2H-tetrazolium diethylhexyl succinate sulfonate (64) 2,3-Diphenyl-5-(quinol-2-yl)-2H-tetrazolium diethylhexylsuccinate sulfonate (65) 2,3-Diphenyl-5-(benzoxazol-2-yl)-2H-tetrazolium diethylhexylsuccinate sulfonate (66) 2,4-Diphenyl-S-nitro-2H-tetrazolium polyacrylate (67) 2,2',3,3'-Tetraphenyl-5,5'~1,4-butylene-di-(2H-tetrazolium) laurylsulfate .
(68) 2,2',3,3'-Tetraphenyl-5,5'-p-phenylene-di-(2H-tetrazolium) cetylpolyethenoxysulfate (69) 2-(4,5-Dimethylthiazol-2-yl)-3,5-diphenyl-2H-tetrazolium polyacrylate (70) 3,5-Diphenyl-2-(triazin-2-yl)-2H-tetrazolium stearate (71) 2-(Benzothiazol-2-yl)-3~(4-methoxyphenyl)-5-phenyl-2H-tetrazolium di-ethylhexylsulfosuccinate (72) 2,5-Diphenyl-3-~-naphtyl-2H-tetrazolium dodecylsulfate (73) 3,3'-(3,3'-Dimethoxy-4t4'-diphenylene)-2,2'5,5'-tetraphenyl~di-(2'-tetrazolium polyacrylate) (74) 5-(3-Methyloxyphenyl)-3-(3-trifluoromethylphenyl)-2-phenyl-te-trazolium isopropylnaphthalenesulfonate (75) 2,3,5-Triphenyl-2H-tetrazolium isopropylnaphthalene-sulfonate The non-diffusible or diffusible tetrazolium compounds according to the invention are thus synthesized by an optional selection of the anionic and cationic moieties. The non-diffusible compounds, e.g. 2,3,5-triphenyl-2H-tetrazolium dioctyl-succinate-sulfonate may dispersed into a gelatin solution by mixing the respective soluble tetrazolium salt and the gelatin first to disperse them in the gelatin solution and then by that optimum anion is admixed thereto thereby to obtain the gelatin solution dispersed with the non-diffusible, tetrazolium compound as specifically mentioned in working Examples set forth lates.
Alternatively, crystals of the non-diffusible tetra-zolium compound purely synthesized may be dissolved in a suitable solvent such as dimethylsulfoxide and then dispersed in the gelatin solution.
When the dispersion is not sufficiently homogeneous, good results may be obtained by exposing the emulslon dispersion to an ultrasonic wave or by use of a suitable homogenizer such as Manton-Gaulin homogenizer.
As mentionea above, the tetrazolium compounds of this invention may be used both in diffusible and non-diffusible orms, when the silver halide of this invention is employed. However, the higher contrast image may be obtained by employing the non-diffusible tetrazolium compounds. Accordingly, it is advantageous to employ the non-diffusible tetrazolium compound when an especially superior dot quality is required.
On the other hand, the use of too much high contrast light-sensitive material sometimes brings about not sufficient reproduction o~ the line-image, particularly those of fine letters and lines. In this case, an image with more superior quality may be obtained by the use of the diffusible tetrazolium compounds.
According to a preferred embodiment of the invention, the tetrazolium compound of the invention is incorporated into a silver halide emulsion layer.
According to another preferred embodiment oE the invention, the compound is incorporated in a layer adjacent -directly (or a layer adjacent to said adjacent layer) to the layer containing the silver halide emulsion.
The above-mentioned compounds of the invention may preferably be employed in an amount of 0.0001 - 10 mole, more preferably 0.001 - 1 mole, per mole of the silver halide contained in the light-sensitive silver halide photographic material of the inven-tion.
The sensitizing dyes used in this invention mean those which can extend a sensitive wave length range of the silver halide outside of its inherent sensitive wave length. Sensitiz ing dyes used ~or this invention cover those such as cyanines, merocyanines, hemicyanines, oxonols, hemioxonols or mixed mero-cyanines. Such dyes are described in e.g. "The cyanine dye and related compounds" by F. M. ~lamer and "The Theory of Photographic Process", Third edition by C. E. Kenneth Mees and T. ~1. James.
The sensitizing dyes of this invention may be concretely expressed by the general formulae LIV~XJ;

^l- - 15 , ,:

~IV,~: " - Z 1 R~ N~=ClI-CH )ml C Ll~L2_L3~--C~CH-CH~j~N-R2 (X~
fvl: z Q- l Rl-N ( CH=CHt~j~~ C~' 0~ :~
~VI~: ", Z1 N ~ CH CH ) m C ~Ll-L2 ~ C

R -~)N~CH-CH~ C~L1 2~;~

(~) Q-1 Q~1 /C L1 ( L2 L3 ) n1 C~ Q2 O I H
,.
2 0 fIX,~: ,~' ", ~/~\~
Q~l ~,C Ll+L2=L3~;~

~o ~X7: " Z
R1-N~CH=CH~C~L1-L2~ IC \F L1~ 2 3 ~- 2 "
--C=~=CH-CH~ R2 ( ) Q-l r-~ ~ 16 ~ .

5~8~

In which Rl, R2 and R3 each represent an alkyl group ~e.g. methyl, ethyl, propyl, butyl and substituted alkyl such as chloroethyl, hydroxyethyl, methoxyethyl, acetoxy-ethyl, carhoxymethyl, carboxyethyl, ethoxycarbonylme-thyl, sulfoethyl, sulfopropyl, sulfobutyl, ~-hydroxy-~-sulfo-propyl, sulfatepropyl, allyl, benzyl, etc.) or an aryl group (e.g. phenyl, carboxyphenyl, sulfophenyl, etc.);
Ll, L2 and L3 each represent a methynyl group including substituted methynyl (e.g. -CH=, -C(C~I3)=, -C(C2H5)=, -c(cll2cooH)=r -C(CH2~ )=, -c (C6H5)=, -C(C6N4COOH)=~
etc.); Zl' Z2 and Z3 each represent an atom or atom groups necessary Eor forming a 5 to 6 membered heterocyclic ring (e.g. thiazoline, oxazoline, selenazoline, thiazole, selenazole, oxazole, benzothiazole, benzooxazole, benzo-quinazole, benzoimidazole, 3,3-dialkyl-indolenine, naphtho-thiazole, naphthooxazole, naphthoselenazole, thienothiazole, 2-pyridine, 4-pyridine, 2-quinoline, 4-quinoline nucleus etc.); P and Q each represent cyano, -COOR4, -COR4 or -SO2R~
in which R4 represents an alkyl group; ~urther Ql and Q2 each represent an atomic group necessary for forming a thiooxazolone ring, a pyrazolone ring, an oxyindole ring, a barbituric acid, a 2 thiobarbituric acid, a 2,4-oxazoli- ;
dinedione ring, a 2,4-thiazolidinedione ring, a 2,4-imida-zolidinedione ring, a 2-thio-2,4-oxazolidinedione ring, a 2-thio-2,4-thiazolidinedione ring, a 2-thio-2,4-selena-zolidinedione ring, a 2-thio-2,5-thiazolidinedione ring, a 2-thiohydantoine ring, a 4-oxazolinone ring, a 4-thia- ;~
zolinone ring or a 4-imidazoline ring, etc., the groups or rings including the substituted; Y represents hydrogen, amino, alkylamino preferably having 1 to 4 carbon atoms ~s~

(e.g. ethylamino, etc.), dialkylamino preferably having 2 to 8 carbon atoms (e.g. dimethylamino, etc.), halogen (e g. chlorine or bromine atom, etc.) or an alkyl group preferably having 1 to 4 carbon atoms (e.g. methyl, etc.);
ml and m2 each represent zero or 1; nl and n2 each represent 0 or 2; X represents an acid anion (e.g. CQ~ , Br~ , ~ , CQ04~ , CH3 ~ S03~ -, C~13S04 ~ C2~15S4 etc.); Q represents 1 or 2 and an intramolecular salt is formed when Q represents 1.

Typical sensitizing dyes having the above general formulae according to this invention will be exemplified below but this is not intended to limit these dyes:

CH = <

(CH2)3S03 C2 5 ~ ~ ~ CH = <

(CII2)3S03 (Cll2)3s '~ < ~D

`

5~

4 ~ S e ~D

CH3 (CII2)3SO~

5. CH3 ~ ~ CH=C - CH= < N --3 CH

6. 12 5 ~ ~-/~ \ N '~ n / c ~
cQ (1H2~2COO (CH2)2COOH

~ ~ -C~l=C - CH=<
(CH2)3SO3 (CH2)3SO3H N

8. C~I3 N ~ CH=C - CI-I=<

(CH2)3SO3 (C 2)3 3 _ 19 ~

Q ~ ~ CH=C-- CH= < ,~

~CH2) 4S0(~) (CE12) 4S03Na 10 .

~ S 1 2.H5 5 ~

I~J (1 2) 3 3 (1H2) 3S03H N (C2 5 3 11. C2H5 --~ CH=CH-CH= / --N N /~ (~
C H ( CH 2 ) 3 S0(~

12 .

J~ CII= -- CH=<

(C 2) 3 3 (CH2) 3S03H-N~3 ,~CN=C ----CH= ~ ~--C

(C~12) 3SO3 (C112) 3S03H N~ ~
C~ ::

14. C2H5 f2H5 C~ ~ N N ~ ~C~Q
~ I ~CH=CH-CH= ~ li C,2 J~J~ ~?, N--~ 1 ` C_~
f~ (CH2) 2CHS03Na (CH2) 2CHs3C113 15. CH3 CH3 CH= [~lC~=< _ 2 5 I(~)C2H5 2 0 16 . Cn CH=CH-6~ oe ¦~ ~J~

17 .

~X > -"~ >=S
O
c2~5 C2~15 CH3-N ~ ~ ~ 5 1 9 . ~ :

CH-CH ~ ~ S

10 20. CH~CH20H

CH-CH ~ > S

1 2 3 ~ :
503Na ;~1.

~ CH-CH=CH-CH~ S

: 20 C2H5 CH2CooH
`:
22. :~

CH=CH ~ -N < 3 C2~5 ~ :
CH-3 ~ SO~
~: :
~ ' - -- 22 - ~

:` ~ : , ` :` i: ,: .

5~

23 .

>CCH-CHcCH-CH lS ~, 24. ;

C2H5-N~=CU C =~ >=CH~

O H C2H5 CH3~;~SO (3 25 .
~-S

CH 2--CH=CH 2 20 26. - -¢~ )=CH-C-- CH~ ~r(3 , C2H5 C2H5 27 .

~LCH~

.

28.
U CH=CH ~ ~r~

29.

~CH-CH~

C2~5 ~ '~
CH2-CH=CH2 These compounds of this invention can readily be synthesized by the methods described in e.g. U. S. Patents 2,213,995, 3,711,288, 2,503,776, 3,576,641, 2,945,763, 3,625,6.98, etc..
These sensitizing dyes according to this invention may be incorporated into a hydrophilic colloid containing the silver halide of this invention and a tetrazolium compound by dissolving them in water or an organic solvent such as methanol and ethanol, which is miscible with water in any ratio and they can be used in single or in combination of two or more.
The incorporation of the sensitizing dyes into said hydrophilic colloid may be any time during the preparation of the silver halide emulsion, but is preferred to be generally after the completion of the second ripening.
The sensitizing dye can be used in an amount of 10 mg to 1 g~ preferably 30 to 300 mg, per one mole of silver halide.
The iight-sensitive silver halide photographic material of this invention, in which the sensitizing dye is incorporated, can shown not only an excellent stability during development but ~$~

also can be sensitized in any preferred spectrum range. In addition, a super sensitization can be expected by use of a combination of two or more sensitizing dyes in general.
~s the silver halide employed for the light-sensitive silver halide photographic material of the invention, there can be included silver halide used for the conventional silver halide photographic materials, e.g. silver bromide, silver chlorobromide, silver iodobromide, silver chloroiodobromide or silver chloride and the like. The average grain size of the silver halide in the inven-tion is 0.05 - 1.5 ~, preferably 0.1 -0.8 ~, and at least 75% grains of the total grains are within a range of 0.6 - 1.4, preferably 0.7 - 1.3 times larger than the average grain size. Furthermore, the silver halide comprises ;
silver chlorobromide or chloroiodobromide containing at least 50 mole % silver chloride. The silver halide of the invention hav-ing the above-mentioned average grain size and the distribution thereof may be prepared by any known method described, e.g. in , U.S. Patents 2,592,250, 3,276,877, 3,317,322, 2,222,264, 3,320,069 and 3,206,313 and in Journal of Photographic Science 12(5), 242-251 (1964). Silver halides prepared by other methods may also be employed in mixture.
According to the most preferred concrete embodiment of the invention, the silver halide of the invention is silver chloroiodobromide or chlorobromide having an average grain size of 0.1 - 0.5 ~ and at least 80~ grains of the total grains being within a range of 0.7 - 1.3 times larger than the average grain size.
The silver halide emulsion of the invention may be sensitized with various kinds of chemical sensitizers. ~s the sensitizer, there can be mentioned, for example, activated -gelatin, sulfur sensitizers (e.g. sodium thiosulfate, aryl thiocarbamide, thiourea or aryl isocyanate, etc.), selenium -sensitizers (e.g. N,N-dimethylserenourea or selenourea, etc.), reducing sensitizers (e.g. triethylenetetramine or stannic chloride, etc.) and various noble metal sensitizers represen-ted by potassium chloroaurite, potassium auriothiocyanate, potassium chloroaurate, 2-aurosulfobenzothiazole methylchloride, ammonium chloropalladate, potassium chloroplatinate and sodium chloro-palladite. The sensitizer may be employed alone, or mixed together. Ammonium thiocyanate may be auxiliarily employed when a gold sensitizer is employed.
The silver halide emulsion of the invention may preferably be stabilized with 5,6-trimethylene-7-hydroxy-s-triazolo(l,5-a3pyrimidine, 5,6-tetramethylene-7-hydroxy- 9-triazolo(l,5 a)pyrimidine, 5-methyl-7-hydroxy-s-triazolo-(1,5-a)pyrimidine, 7-hydroxy-s-triazolo(1,5-a)pyrimidine, 5-methyl-6-bromo-7 hydroxy-s-triazolo(1,5-a)pyrimidine, esters or salts of gallic acid (e.g. isoamyl gallate, dodecyl gallate, propyl gallate or sodium gallate), mercaptans (e.g. 1-phenyl-5-mercaptotetrazole or 2-mercaptobenzothiazole), benzotriazoles (e.g. 5-bromobenzotriazole or 4-methylbenzotriazole) and benzimidazoles ~e.g. 6-nitrobenzimidazole). Such stabilizers are described in, e.g. U.S. Patents 2,444,607, 2,716,062, 3,512,982, 3,34~,596l 3,726,686 and 3,717,465, British Patent 1,363,921. Furthermore, the silver halide emulsion of the invention may contain a latent image stabilizer such as a sulfur-containing amino acid, or a gradation-adjusting agent such as a cadmium or rhodium salt, described in, e.g. British Patent 1,343,904 and U.S. Patent 3,821,295 ~ ~ 55~3~

It has been known in, e.g. British Patent 775,197 and U.S. Patent 3,488~709, to employ a rhodium or cadmium salt to increase the contrast of silver halide emulsion. However, problems still remain when the rhodium salt is employedO For example, the use of rhodium salt kends to cause an unevenness of the product due to the minute amount of addition and the narrow allowable range thereo~ of the salt, and thus makes it difficult to produce stable photographic material. In case of the cadmium salt, it has to be added as little as possible from an ecological viewpoint, for it is washed out by film-processing and comes finally in~o the environment. The cadmium salts are ~`
known to prevent the metabolism and to be harmful to living tissues. Cadmium may be detected not only in air but also in the body of sea animals. As a result of interest in public health and in the maintenance of normal ecological balance in view of the toxicity o~ rare metals, including cadmium mentioned above, the inventors have reached the invention relating to a novel method to obtain a light-sensitive material with su~fi~ -ciently high contrast, even in no use of such harmful metals when the above-mentioned silver halide, tetrazolium compound and sensitizing dye of the invention are incorporated into the hydrophilic colloidal layer.
The hydrophilic colloid advantageously employed in the invention is gelatin. As other hydrophilic colloids than gelatin, are mentioned, e.g. colloidal albumin, agar, gum arabic arginic acid, hydrolyzed cellulose acetate,acrylamide, imidated polyamide, polyvinyl alcohol, hydrolized polyvinyl acetate, water-soluble polymer described in, e.g~ British Patent 523,661, U.S. Patents 3,847,620, 3,655,389 and 3,341f332, gelatin derivatives such as phenylcarbamyI-, acylated- or phthalated-gelatin described in, e.g. U.S. Patents 2,614,928 and 2,525,753, or graft-polymerized monomers on gelatin having the ethylene group and being capable of polym~rization, such as acrylic acid and the ester thereof, styrene, a methacrylic acid and -the ester thereof, described in, e.g. U.S. Patents 2,548,520 and 2,831,767.
Such hydrophilic colloids may also be applied to a layer contain-~ing no silver halide, e.g. an antihalation layer, a protective layer or a intermediate layer.
The light-sensitive silver halide material of the invention may be prepared by coating the above-mentioned layer containing the silver halide, the sensitizing dye and the tetra-zolium compound of the invention on a suitable photographic support. As the representative supports employed in the invention are mentioned, e.g. a baryta paper, a polyethylene-coated paper, a synthetic polypropylene paper, a glass plate, a cellulose acetate or cellulose nitrate film, a polyester film such as a polyethylene terephthalate film, a polyamide film, a polypropylene film, a polycarbonate film, a polystyrene film and the li]ce. The supports are`optionally selected depending on the purpose for which the light-sensitive photographic material is used.
As mentioned above, the light-sensitive silver-halide photographic material of the invention comprise at least one hydrophilic colloidal layer, coated on a support, containing a silver halide o the invention and a sensitizing dye and a tetrazolium compound.
It is preferable in the light-sensitive material of the invention that a protective layer having a suitable thickness is coated. The protective layer is advantageously a gelatin layer, the thickness of which is preferably 0.1 - 10 ~, more preferably 0.8 2.0 ~.

~.

~9i ~ ?~

The presence of the protective layer may act effec-tively on the stability of the image quality and of the developing process in this invention. This is presumed because, the protective layer may have a function to control adequately the iniltration rate of the hydroquinone/Metol or phenidone from the processing solution into the light-sensitive material, or the diffusion rate of the tetrazolium compound within the light-sensitive material or therefrom to the process-ing solution. This efect is remarkable when the tetrazolium compound of the invention is employed. The effect is not so remarka~lewhenother oxidizing agents than the tetrazolium com-pound, aescribed in, e.g. German Patent Application D.O.S.
2634666 published on February 7, 1977, are employed.
Various kinds of photographic additives may optionally be added to the above-mentioned hydrophilic colloid of the invention, as far as they do not impair the effect of the invention. As the additives, there can be used, e.g. a gelatin plasticizer, a hardening agent, a surface active agent, a image stabilizer, an ultraviolet absorber, an anthistaining agent, a pH adjuster, an antioxidant, an antistatic agent, a viscosity-increasing agent, a granularity improving agentl a dye, a mordant, a brightening agent, a development regulator, a matting agent, and the like.
Among the additives mentioned above, the following may particularly and prefPrably be employed: viscosity-increasing agents and plasticizers, described in U.S. Patents 2,960,404 and 3,767,410, 3,659,~56 and 3,692,753, e.g. a styrene/sodium maleate copolymer and dextran sulfate~ etc.; hardening agents of an aldehyde, epoxy, ethyleneimine, active halogen, vinylsulfone, isocyanate, sulfonic acid ester, carbodiimide, mucochloric acid ~ 29 -.

5~

or acryloyls, etc.; image stabilizers, e.g. 6,6'-butylidene-bis(2~t-butyl-4-methylphenol) and 4,4'-methylene-bis(2,6-di-t-butylphenol), etc.; ultraviolet absorbers, described in, e.g.
U.S. Patent 3,253,921, British Patent 1,309,349, U.S~ Patents 3,533,794 and 3,707,375 and British Patent 1,287,770, particu larly 2-(2-hydroxy-5-t-butylphenyl)benzotriazole, 2-(2-hydroxy-3,5-di-t-butylphenyl~benzotriazole, 2-(2-hydroxy-3-t-butyl-5-butylphenyl)-5-chlorobenzotriazole and 2-(2-hydroxy-3,5-di-t-butylphenyl)-5-chlorobenzotriazole; surface active agents or coating aids, emulsifiers, infiltration-improving agents for processing solution, defoamers, or agents for controlling various physical proper~ies of the light-sensitive material, described in, e.g. U.S. Patents 3,026,202 and 3,514,293, British Patents 548,532 and 1,216,389, U.S. Patent 3,726,683, including anionic,cationic, nonionic and amphoteric compounds; mordants described in, e.g.
U.S. Patents 2,113,381 and 2,548,564; antistaining agents described in, e.g. U.S. Patents 2,360,210, 2,728,659, 2,732,300 and 3,700,453, particularly 2-methyl-5-hexadecylhydroquinone, 2-methyl-5-sec-octadecylhydroquinone and 2,5-di-t-octylhydro-quinone, etc.; antistatic agents described in, e.g. U.S. Patents2,882,157, 2j972,535 and 3,573,093 and British Patent 1j378,584 and U.S. Patents 3,549,369, 3,704,128 and 3,663,230; matting agents described in, e.g. U.S. Patents ~,992,101 and 2,956,884, British Patent 1,221,980 and British Patent 1,307,373,particu-larly silica gel having a grain size of 0.5 - 20 ~ and poly-- methylmethacrylate having a grain size of 0.5 - ~0 ~; developing promotors, e.g. benzyl alcohol and a polyoxyethylene series compoùnd which may be added in the processing bath.
In accordance with the process of the invention, there is obtained a high contrast silver image. The lnvention is ~ - 30 -there~ore applicable to various fields wherein a high contrast black and white recording is required. The light-sensitive material of the invention is, for example, applied preferably to a printing- or micro- sensitive material. The process of the invention for forming a lith type photographic image has superior characteristics which no conventional processes have reached yet. It is not necessarily elucidated why the high contrast silver image may be obtained according to the process of the invention. It is presumed that the semiquinone produced by oxidation of hydroquinone in the developing solution by the tetrazolium compound may be accumulated in an abnormally high concentration near the developed silver. It is said, in general, that the so-called "infectious phenomenon" does not take place due to instantaneous removal of the semiquinone or quinones by sulfonation when the sulfite ions are in a high concentration in the developing solution. Whereas, in the present process, it is presumed as if the infectious development takes place at the position of the exposed silver halide in the gelatin layer due to predominant supply of the semiquinone.
It is accordingly essential in the process of the invention to treat with a developing solution containing a hydroquinones developing agent. The lith type developing solution (infectious developing solution), however, is not essentially required as far as the solution is oE hydroquinones by which high contrast lith type silver image may sufficiently be obtained even in the presence o~ sulfite ion in a high concentration. The process of the invention differs apparently from the conventional processes in that no conventional lith type developing solution which contains hydroquinone, alkali, alkali metal bromide, sulfite ion in low concentration, and as a preserver a condensation product of formaldehyde/sodium bisulfite or carbonylbissulfite amine is neededr although the use of such components may of course be possible.
As the hydroquinone type developing agents employed in the invention are mentioned, e.g. hydroquinone, chloro-hydxoquinone, bromohydroquinone, isopropylhydroquinone, tolu-hydroquinone, methylhydroquinone, 2,3-dichlorohydroquinone, 2,5-dimethylhydroquinone, 2,3-dibromohydroquinone, 2,5-dihydroxyacetophenone, 2,5-diethylhydroquinone, 2,5-di~p-phenethylhydroquinone, 2,5-dibenzoylaminohydroquinone, and the like.
The developing solution containing the hydroquinones developing agent employed in the invention includes not only the so-called lith type developing agent but also the gradient MQ
and PQ developing solution, the latters of which are advantage-ously employed in the invention because of the easiness of preparation and superior preservability. Among these developing solutions, those which show the superadditivity are preferred.
For example, the developing agents and the additives therefor described in "The Theory of Photographic Process", Third Edition, pp 374-378 (1966) are advantageously employed. A preserver like sulfite salts such as sodium sulfite, potassium sulfite or ammonium sulfite may jointly be employed in the developing solution used in the invention without impairing the effect of the invention; and this is another characteristic of the invention.
The adjustment of pH and giving a bufer function with an alkali hydroxide, alkali carbonate or amine, or addition of inorganic development retarder such as potassium bromide or of organic development retarder such as benzotriazole may optionally be carried out as in the standard black and white developing solution.

;i5~

In the invention the phrase "treat with a developing solution containing hydroquinones developing agent" means to -carry out development of the exposed material of the invention with the developing solution which satisfies the above-mentioned conditions, and various modes may be included therein. For example, the temperature at which development is carried out is preferably below 50C, more preferably around 30C, and the time required for devèlopment is generally within 30 minutes, more preferably within 5 minutes, by which good results are obtained, in general.
Ater the development, the subsequent processes such as washing, stopping, stabilizing and fixing are carried out.
If necessary, processes like prehardening and neutralization and the like may be adopted, but they may optionally be omitted.
The processes may be carried out either by the so-called manual treatment like a bath- or tray-development or by the mechanical treatment like a roller- or hanger-development. ~ccording to a preferred embodiment of the invention, the processing solution in the bath development was more than 20 times more stabler over long period than the conventional lith type developing solution.
Especially, when the known particular developing sol~tion containing-sulfite ion in an extremely low concentration is employed in order to improve the dot quality of the lith type light-sensitive material, it became of no use for several hours.
While, according to a preferred method of the invention, the processing solution could be stably employed after one month has passed, and the dot quality using the solution was then comparable to that using a newly prepared solution.
Furthermore, addition of a contrast agent often used for the conventional high contrast developing solution to _ 33 _ .

the developing solution employed in the invention gives no undesirable in1uence on the photographic quality.
As can be clearly understood by the explanations given above, the invention relates to a novel light-sensitive silver halide photographic material and the processing method thereof which may obtain a superior stable line- or dot image by processing the light-sensitive silver halide photographic material comprising a sensitizing dye, a tetrazolium salt and a silver halide having a narrow grain size distribution, with a developing solution containing hydroquinone, using no infectio~s developing solution.
According to the process of the invention, there is obtained a stable high con~rast silver image even when the diffusible tetrazolium compound is employed. There may also be obtained a stable dot image which is superior to that obtained by the method described in German Patent Application D.O.S. 2634666 published on ~ebruary 7, 1977, when the non-diffusible tetrazolium compound is employed.
The invention is further concretely explained by the following Examples, which by no means restrict the scope of the invention and various many modified embodiments may be possible: .
Example l A silver chlorobromide-gelation emulsion in fine grain size state containing silver halide of 90 mole ~ of silver chlo-ride, 9 mole % of silver bromide and 1 mole % of silver iodide was chemically sensitized with a sulfur and gold sensitizing agent. This emulsion had an average grain size of 0.25 ~ and 75% of the whole grains were within a range of 0.19 to 0.31 in grain size. To this emulsion 8 g o 2,3,5-triphenyltetrazolium ~ ~ 3~ ~

chloride per one mole of silver and the equimolar amount of diethylhexylsuccinate sulfonate (hereintoafter, referred to as DES) were added. This emulsion was coated on a polyethylene telephthalate support so as to contain 53 mg of silver/100 cm2 ~nd 50 mg of gelatin/100 cm . Next, this pho-tographic element was wedge-exposed through a gray contact screen of intermediate tone with a tungsten lamp and processed by the following treat-ments at 30C.
Development 1.5 minutes Water washing 1 "
Fixing 2 "
Water washing 5 "
Drying.
The following composition were employed in the processing bath:
[Developing solution~ ~, Metol 3.5 g ~nhydrous sodium sulfite 60 g Hydroquinone 9.0 g Sodium carbonate 54 g Potassium bromide 2.5 g --5-Nitrobenzimidazole 0.5 g l-Phenyl-5-mercapto-tetrazole 10 mg Water to make 1 litre (pH=10 D 25) [Fixing solution]

Ammonium thiosulfate decahydrate 150 mg - Anhydrous sodium sulfite 10 g Sodium acetate trihydrate . 15 g ~5~'~'$

Glacial acetic acid 15 mQ
Water to make 1 liter (pH=6.80) "Dot quality" here in the examples of this invention means an estimated value of reproduced halftone dot images.
Halftone images obtained rom the exposed and then developed lith type light-sensitive photographic material are composed of the part called generally "shadow dot" and the part known as "highlight part". There is an intermediate part of various areas in size between both the ends. "Dot quality" here means an evaluated value of the dot in the part having 50 ~ dot in which a half of a definite area is clear and the rest of it is a developed image and the dot quality is expressed in progressive scale. That is~ 11411 means excellence and "1" extremely badness.
The dot quality below 3 can not be generally permitted.
To this emulsion was incorporated ~xemplified sensitizing dye No. 14 dissolved in methanol in an amount of 200 mg per one mole of silver (Sample 2).
The results obtained are shown in Table 1.

.5~

Table 1 _ Sensitiæing Development Relative F Dot Sample dyetime(s) sensitivity og quality No addition 60 60 0.01 3.0 of the dye 80 100 0.02 3.7 1 (outside of .
this 100 120 0.03 3.3 . invention) 120 130 0.04 3.0 _ _ 0.01 3.3 Compound No. 14 _ 0.02 3.7 2 (within this _ 100 100 0.02 3.7 . invention) . _ 120 110 0.02 3.3 _ Table 1 shows that the light-sensitive material according to this invention does not vary in specific sensitivity and fog with the development time compared with other materials than this invention and the variation of dot quality is also small.
Example 2 A silver halide emulsion was prepared which comprises a silver chlorobromide emulsion containing silver halide of 60 :
mole % of silver chloride and 40 mole % of silver bromide and of which the average grain size is 0.3 ~ and 75% of the whole grains is within a range of 0.24 to 0.37 ~.
To this emulsion hexaamminecobalt (III) trichloride was added in amount of 4.0 g per one mole of silver. After the sensitizing dye No. 10 was added in an amount of 200 mg per one mole of silver, the emulsion was coated on a polyethylene terephthalate support so as to contain 55 mg of silver per 100 cm2 and 30 mg of gelatin per 100 cm2 and dried.

~ 37 - :

.

(Sample 3) Next, a similar sample was prepared as above except that 3.0 g of 2.5-diphenyl-3-~~napthtyltetrazolium chloride (35) was added instead of hexaamminecobalt (III) -trichloxide ~Sample 4) These samples were treated in the same way as in Example 1 together with Sample 5 containing no oxidant.
The results are shown in Table 2.
Table 2 ` :~
Development Relative Fo Dot Sample time(s) sensitivity g quality _ _ Sample 3 60 30 _ 2.0 0.01 2.3 (outside of this 100 80 0.01 2.5 invention) 120 150 0.02 2.0 . 60 80 0.01 2.7 Sample 4 .
100 0.01 3.5 . _ . ~within this 100 110 0.01 3.3 ~:
invention) _ :~
120 130 0.01 3.0 sa~ple 5 60 130 0.03 bad . 80 180 0.07 ." ~"~
(outslde of . _ ._ this ` 100 220 0.10 : :
invention) 120 280 0.20 _ Table 2 shows that Sample 4 of this invention has an excellent dot quality compared with Samples 3 and 5.
Example 3 A silver halide emulsion which comprises a silver bromide emulsion, in which the average grain size is 0.25 ~ and about 75% of the whole grains is within a range of 0.19 to 0O31 ~, was chemically sensitized with a gold sensitizer. Into this emulsion was added 4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene in an amount of 500 mg per one mole of silver. This emulsion was coated on a polyethylene tereph-thalate film supp~rt in an amount of 50 mg of silver per 100 cm2 and dried. In this case, the following compounds were added after chemical ripening to obtain the following samples.
Sample 6: Hexaamminecobalt (III) isopropylnaphthalenesulfonate was added to this emulsion in an amount of 5.0 g per one mole of silver.
Sample 7: Compound No. 12 of the sensitizing dye was added to Sample 6 in an amount of 220 mg per one mole of silver.
Sample 8: This sample was prepared in the same way as in Sample 7 except that 2,3,5-triphenyl-2H-tetrazolium isopropyl-naphthalenesulfonate (tetrazolium Compound (75)) was added in the same mole amount instead of hexaamminecobalt ~III) isopropyl-naphthalenesulfonate.
Sample 9: Tartrazine{4,5-dihydro-5-oxo~ sulfonyl)-4-1(4-sulfonyl)azo~-lH-pyrazole-3-carboxylic acid trisodium salt~
was added to Sample 8 in an amount of 100 mg per one mole of silver.
These samples were treated in the same way as in Example 1 except that they were developed by the following developing solution at 30C for 60, 80, 100, 120 and 140 seconds.
Composition of the developing solution l-~henyl-3-pyrazolidone0.8 g Anhydrous sodium sulfite 45 g Potassium hydroxide10 g Hydroquinone 20 g Anhydrous sodium carbonate - 20 g 6-Nitroindazole 0.1 g Pure water to make 1 Q
The results ohtained are shown in Table 3.
Table 3 Development Relative Dot Sampletime(s) sensitivity og quality ., _ .
0.01 2.0 0.01 3.0 _ Sample 6100 100 0.02 3.2 . _ 120 140 0.03 3.0 ~ :
. 140 170 0.04 2.5 _ 0.01 2.5 _ _ _ .
0.01 3.0 _ Sample 7100 95 0.01 3.5 120 107 0.02 3.7 140 120 0.03 3.0 . .
0.00 3.0 _ 0.01 3.5 Sample 8100 100 0.01 3.8 _ 120 100 0.01 3.8 _ 14-0 103 0.01 - 3.5 _ 0.00 3.0 . _ ..
OoOl3.5 .
Sample 9 100 97 0.01 4.0 _ _ _ ~

120 102 0.01 4.0 _ 140 107 0.01 3.5 _ __ Table 3 shows the following facts: even in the case of using non-diffusible oxidants except the tetrazolium salt, some effects could be expected but the use of the tetrazolium salt .. -- ~0 --, :

produced remarkable effects. The use of an irradiation prohibiting dye such as Tartrazine except the sensitizing dye has some effects for raising the dot quality but has no e~fect for processing stably the development and giving skable characteristics as in this invention.
Example 4 In this example the same emulsion as in Example 3 was used and the following compounds were added after the emulsion was chemically sensitized.
Sample 10: 3-(p-~ydroxyphenyl)-5-methyl-2-phenyl-2H-tetrazolium chloride (tetrazolium Compound (18)) was added in an amount of !
3.0 g per one mole of silver.
Sample 11: To sample 10 was further added Compound No. 23 of the sensitizing dye in amount of 150 mg per one mole of silver.
These sample were treated with the same development process as in Example 1 except that they were developed for 80, 100, 120 and 140 seconds.
The results obtained are shown in Table 4.
Table 4 Sample time(s) sensitivity Fog _ quality 0.004.0 2.0 . , 100 87 0.018.0 2.7 ~ , Sample 10 120 1~0 0.0310.0 3.0 140 135 0.059 3 2.7 _80 0.017.0 2.5 100 100 0.0110.0 3.0 Sample 11 _ _ 120_ 107 ~.0210.0 3.0 _ ~40112 0.039 5 3.0 , .

Table 4 shows that the sample, in which the sensiti~ing dye was added, has a higher stabili~y during the development process than that having no addition.
Example 5 This sample was p~epared in the same way as in Example 4 using the dye compound No. 23 so as to have an average grain size of 0.25 ~ by mixing single diffraction emulsions hav-ing 0.015 ~ and 0.035 ~ at peaks. :
The results obtained are shown in Table 5.
Table 5 _ _ .
Sensitizing Development Relative Fo Dot dye time(s) sensitivity g quality 0.011.5 100 0.022.0 No addition 100 130 0.032.5 ~ :
_ .
120 ` 150 0.04_1.5 _ 0.011.5 :
. 200 mg of Compound .
110 0.022.0 23 was added per one mole of 100 137 0.032.7 silver ~
120 155 0.032.0 ~:
' 2Q Table 5 shows that sufficient effects can not obtained whenthe grain size distribution is wider than the scope of that of this invention. ~:

.

, .. ..

Claims (12)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows :

1. A light-sensitive silver halide photographic material saidmaterial comprising support and at least one hydrophilic colloidal layer coated on said support, said layer containing :
a) silver halide grains having an average grain size of from 0.05 to 1.4 µ at least 75% of said grains being within a range of 0.6 to 1.4 times the average grain size, b) a tetrazolium compound, said tetrazolium compound being selected from the group consisting of the compounds of formula (I), (II) and (III) :

(I) (II) (III ) where r1, r3, R4, R5, R8, R9, Rl0 and Rll each represents an aryl group or a heterocyclic group ; R2, R6 and R7 each repre-sents an aryl group, a heterocyclic group, an alkyl group, hydroxyl, carboxyl or the salt thereof, an amino group, mercapto, nitro or hydrogen; D represents a divalent aromatic group; E
represents an alkylene group, an arylene group or an aralkylene group; X is an anion, said heterocyclic group being selected from the group consisting of a thiadiazolyl, benzothiadiazolyl, oxazolyl, pyrimidinyl, pyridyl and 2,5-dimethyl-thiadiazolyl group; and n is 1 or 2, provided that the tetrazolium compound forms an intramolecular salt when n is l; and c) a sensitizing dye, said sensitizing dye being present in said hydrophilic colloidal layer and being selected from the group consisting of the compounds of general formulae (IV) through (X) : .
(IV):

(V) : (VI):
(VII):
(VIII ):

(IX):

(X): ' wherein Rl, R2 and R3 each represents an alkyl group or an aryl group~ Ll, L2 and L3 each represents a methynyl group, Zl' Z2 and Z3 each represents an atom or atomic group necessary for forming a 5 to 6-membered heterocyclic ring, P and Q each represents cyano, -COOR~, -COR4 or -S02R4 in which R4 represents an alkyl group, Ql and Q2 each represents an atomic group necessary for forming a thiooxazolone ring, a pyrazolone ring, an oxyindole ring, a barbituric acid, a 2-thiobarbituric acid, a 2,4-oxazolidinedione ring, a 2,4-thiaxolidinedlone ring, a 2,4-imidazolidinedione ring, a 2-thio-2,4-oxazolidinedione ring, a 2-thio-2,4-thiazolidinedione ring, 2-thio-2,4-selenazolidinedione ring, a 2-thio-2, 5-thiazolidinedione ring, a 2-thio-hydantoine ring, a 4-oxazolinone ring, a 4-thiazolinone ring or a 4-imida-zoline ring; Y represents hydrogen, amino, alkylamino, dial-kylamino, halogen, an alkoxy group or an alkyl group; ml and m2 each represents 0 or 1; nl and n2 each represents 0 or 2;
X represents an acid anion group; and ? represents 1 or 2 provided that the sensitizing dye compound forms an intramolecular salt when Q is 1.

2. A light-sensitive silver halide photographic material according to Claim 1 wherein the tetrazolium compound is non-diffusible.

3. A light-sensitive silver halide photographic material according to Claim 1 wherein the tetrazolium compound is diffusible.

4. A light-sensitive silver halide photographic material according to Claim 1 wherein the hydrophilic colloidal layer is a gelatin layer.

5. A light-sensitive silver halide photographic ma-terial according to Claim 1, wherein the silver halide is silver chlorobromide or silver chloroiodobromide containing at least 50 mole % silver chloride and having an average grain size of from 0.1 to 0.5 µ, at least 80% of said grains being within a range 0.7 to 1.3 times the average grain size.

6. A light-sensitive silver halide photographic material according to Claim 1 wherein the light-sensitive silver halide photographic material further comprises an outermost gelatin protective layer having a thickness of from 0.1 to 10 on the hydrophilic colloidal layer.

7. A light-sensitive silver halide photographic material according to Claim 1 wherein the hydrophilic colloidal layer contains the tetrazolium compound.

8. A light-sensitive silver halide photographic material according to Claim 7 wherein the hydrophilic colloidal layer further contains the sensitizing dye.

9. A light-sensitive silver halide photographic material according to Claim 1 wherein the photographic material further comprises a gelatin layer adjacent to the hydrophilic colloidal layer, the gelatin layer containing the tetrazolium compound while the hydrophilic colloidal layer contains the sensitizing dye.

10. A light-sensitive silver halide photographic material according to Claim 1, wherein said sensitizing dye is selected from the group consisting of :

2.

3.
4. 5. 6. 7. 8.

10 .

11 .

12 .

13. 14. 15. 16. 17. 18 .

19 .

20 .

21 .

22 .

23 .

24 .

25 .

26 .

27 .

28 .

and 29 .

11. A light-sensitive silver halide photographic material according to Claim l, wherein said tetrazolium compound is selected from the group consisting of :
(1) 2-(Benzothiazol-2-yl)-3-phenyl-5-dodecyl-2H-tetrazolium (2) 2,3-Diphenyl-5-(4-troctyloxyphenyl)-2H-tetrazoliumm (3) 2,3,5-Triphenyl-2H-tetrazolium (4) 2,3,5-Tri-(p-carboxyethylphenyl)-2H-tetrazolium (5) 2-(Benzothiazol-2-yl)-3-phenyl-5-(o-chlorophenyl)--2H-tetrazolium (6) 2,3-Diphenyl-2H-tetrazolium (7) 2,3-Diphenyl-5-methyl-2H-tetrazolium (8) 3-(p-Hydroxyphenyl)-5-methyl-2-phenyl-2H-tetrazoliium (9) 2,3-Diphenyl-5-ethyl-2H-tetrazolium (10) 2,3-Diphenyl-5-n-hexyl-2H-tetrazolium (11) 5-Cyano-2,3-diphenyl-2H-tetrazolium (12) 2-(Benzothiazol-2-yl)-5-phenyl-3-(4-tolyl)-2H-tetrazolium (13) 2-(Benzothiazol-2-yl)-5-(4-chlorophenyl)-3-(4-nitrophenyl)-2H-tetrazolium (14) 5-Ethoxycarbonyl-2,3-di(3-nitrophenyl)-2H-tetrazolium (15) 5-Acetyl-2,3-di(prethoxyphenyl)-2H-tetrazolium (16) 2,5-Diphenyl-3-(p-tolyl)-2H-tetrazolium (17) 2,5-Diphenyl-3-(priodophenyl)-2H-tetrazolium (18) 2,3-Diphenyl-5-(p-diphenyl) 2H-tetrazolium (19) 5-(p-Bromophenyl)-2-phenyl-3-(2,4,6-trichlorophenyl)-2H-tetrazolium (20) 3-(p-Hydroxyphenyl)-5-(p-nitrophenyl)-2-phenyl-2H
tetrazolium (21) 5-(3,4-Dimethoxyphenyl)-3-(2-ethoxyphenyl)-2-(4-methoxy-phenyl)-2H-tetrazolium (22) 5-(4-Cyanophenyl)-2,3-diphenyl-2H-tetrazolium (23) 3-(p-Acetamidophenyl)-2,5 diphenyl-2H-tetrazolium (24) 5-Acetyl-2,3-diphenyl-2H-tetrazolium (25) 5-(Fur-2-yl)-2,3-diphenyl-2H-tetrazolium (26) 5-(Thien-2-yl)-2,3-diphenyl-2H-tetrazolium (27) 2,3-Diphenyl-5-(pyrid-4-yl)-2H-tetrazolium (28) 2,3-Diphenyl-5-(quinol-2-yl)-2H-tetrazolium (29) 2,3-Diphenyl-5-(benzoxazol-2-yl)-2H-tetrazolium (30) 2,3-Diphenyl-5-nitro-2H-tetrazolium (31) 2,2',3,3'-Tetraphenyl-5,5'-1,4-butylene-di-(2H-tetrazolium) (32) 2,2',3,3'-Tetraphenyl 5,5'-p-phenylene-di-(2H-tetrazolium) (33) 2-(4,5-Dimethylthiazol-2-yl)-3,5-diphenyl-2H-tetrazolium (34) 3,5-Diphenyl-2-(triazin 2-yl)-2H-tetrazolium (35) 2-(Benzothiazol-2-yl)-3-(4-methoxyphenyl)-5-phenyl-2H-tetrazolium (36) 2,5-Diphenyl-3-.alpha.-naphthyl-2H-tetrazolium, and (37) 3,3'-(3,3'-Dimethoxy-4,4'-diphenylene)-2,2',5,5'-tetraphenyl-di-(2H-tetrazolium).

12. A method of processing a light-sensitive silver halide photographic material, as defined in Claim 1, after imagewise exposure to light, comprising the step of treating said material with a developing solution containing a hydro-quinone and Metol or phenidone.