EP0243168B1

EP0243168B1 - Method for processing silver halide photo-sensitive material

Info

Publication number: EP0243168B1
Application number: EP19870303532
Authority: EP
Inventors: Kazuhiro Murai; Keiji Ohbayashi; Kaoru Onodera
Original assignee: Konica Minolta Inc
Current assignee: Konica Minolta Inc
Priority date: 1986-04-22
Filing date: 1987-04-22
Publication date: 1991-10-16
Anticipated expiration: 2007-04-22
Also published as: EP0243168A2; JP2591616B2; EP0243168A3; DE3773730D1; JPS6346454A; CA1306895C

Description

The present invention relates to a method for processing silver halide photo-sensitive materials, in particular to a method for fast and stably processing silver halide photo-sensitive materials which is capable of preventing fog from increasing.
In general, a silver halide color photo-sensitive material is provided with three kinds of silver halide color emulsion layer each selectively and spectrometrically sensitized so as to be sensitive to blue light, green light and red light, respectively, applied on a support member. For example, a color negative photo-sensitive material is generally provided with a blue light-sensitive emulsion layer, a green lightsensitive emulsion layer and a red light-sensitive layer applied in this order from the side exposed. A bleachable yellow filter layer is disposed between the blue light-sensitive emulsion layer and the green light-sensitive emulsion layer to absorb blue light passing through the blue light-sensitive emulsion layer. In addition, each emulsion layer is provided with other intermediate layers and a protective layer as the outermost layer for various purposes. For example a color printing paper photo-sensitive material is generally provided with a red light-sensitive emulsion layer, a green light-sensitive emulsion layer and a blue light-sensitive emulsion layer applied in this order from the side exposed. In addition, the color printing paper photo-sensitive material is provided with an intermediate layer, a protective layer and the like in addition to an ultraviolet ray-absorption layer, in the same manner as in the color negative photo-sensitive material. It has been known that these emulsion layers can be arranged in a manner other than that described. It has been known also that a sensitive emulsion layer consisting of two layers having a sensitivity in substantially the same wave length range to light of each color is used as the emulsion layer. For these silver halide photo-sensitive materials for example an aromatic primary amine color developing agent is used as color developing agent. Silver halide particles exposed are developed and a reaction between an oxidized product of the color developing agent and a dye forming coupler leads to the formation of a dye image. In this method, in general, in order to form a cyan, magenta or yellow dye image, a cyan, magenta or yellow dye-forming coupler is used, respectively.
Recently, a silver halide color photo-sensitive material (hereinafter referred to as a color sensitive material), which can be fast and stably processed, giving a high image quality, without being expensive, has been desired. In particular, a fast processable silver halide color photo-sensitive material has been desired.
That is to say, a silver halide photo-sensitive material is sujected to a continuous process in an automatic developing machine in a developing shop but there has been a need to develop and provide the finished material to the user within the same day so as to improve the service for the user. Recently, it is being required even to provide the finished material to the user within a few hours of receipt. Thus, the rapid development of an increasingly fast processable silver halide color photo-sensitive material is desired.
Although in general the formation of such a dye image comprises a color developing process, a bleaching process, a fixing process (or a bleach fixing process) and a washing process of an exposed color sensitive material, it is very important in respect of technique and practical use for there to be a color printing paper requiring particularly fast processability to shorten the time required for the color developing process.
In order to speedily carry out the color developing process, measures, such as raising the developing temperature, a reduction in the concentration of bromide ion, which is the main ingredient of a development inhibitor, a rise in the concentration of the color developing agent and a rise in pH, have been most usually been taken.
The speed-up of the color developing process can be achieved also by processing a silver halide photo-sensitive material containing silver halide particles substantially comprising silver chloride in the presence of a bromide ion in a color developer.
However, in the event that the speed-up of the color developing process is carried out by the above described various measures, a problem occurs in that a slight change of conditions (temperature, pH, time and the like), a slight change of composition (concentration of bromide ion and concentration of a color developing agent) or contamination of a minute amount of bleach fixing solution are apt to cause fogging.
Recently there has been a strong desire to remove benzyl alcohol as a dye formation-improving agent from a color developer in view of pollution control. If benzyl alcohol is removed from the color developer, the dye formation speed is reduced. That is to say, the color developing agent develops exposed silver halide particles, such that the reacting capacity between the resulting oxidized product of the color developing agent and the coupler is suddenly reduced so that it is difficult to obtain high color.
It has been found that such a problem (the reduction of color concentration) occurring in the event that benzyl alcohol is removed is particularly due to hydroxyl amine salt used in the color developer as a preservative.
It is known that in the usual color developer the hydroxyl amine salt serves as a superior preservative for preventing the color developing agent from being oxidized with air, particularly in the event that it is used together with sulfite salts. Moreover, in the event that a color sensitive material is processed with a color developer containing benzyl alcohol at pH of about 10, its influence upon the coloring capacity is remarkably small.
However, since hydroxyl amine peculiarly reduces the color concentration in the event that the developing process is carried out with a color developer without containing benzyl alcohol, a method of fast color development capable of reducing an adverse effect upon the maximum density and the gradation by using other preservatives in place of hydroxyl amine is necessary.
Some preservatives for the color developer have been proposed in place of hydroxyl amine. Among them hydroxyl amine derivatives having at least one substituent on the nitrogen atom are useful as compounds having a sufficient preservative capacity without significantly reducing the coloring capacity even in the event that the concentration of color developer is sufficiently high and benzyl alcohol is not present.
However, on the other hand, if such a hydroxyl amine derivative is used in place of hydroxyl amine as a preservative in the event that the process is carried out with a color developer without containing benzyl alcohol, the dye image of a silver halide photo-sensitive material can reach the maximum density quickly but a disadvantage occurs in that the fog is apt to be generated when the dye image of the silver halide photo-sensitive material has reached the maximum density.
It has been known that mercapto compounds are preferably used as fog inhibitors. Although mercapto compounds are effective as fog inhibitors, they exhibit an insufficient effect such that fog is apt to be generated in the event that the color developing process is speeded up in the above described manner.
It is an object of the present invention to provide a method for processing a silver halide photo-sensitive material in which the pollution load is reduced by removing benzyl alcohol from the color developer and a dye image can be fast formed by carrying out a color developing process in the presence of a specific hydroxyl amine derivative, thereby restraining fog, with a reduced sensitivity or gradation fluctuation due to a change in pH.
Thus the present invention provides a method of processing a light-sensitive silver halide color photographic material which comprises processing an image-wise exposed light-sensitive silver halide color photographic material comprising a support and, provided thereon, at least one silver halide emulsion layer containing silver halide grains which are sensitized with a sensitizing dye represented by general formula 111;
(wherein, Z₁ and Z₂ are independently represent a group of atoms necessary to complete a heterocyclic ring which is a thiazole, a benzothiazole, a selenazole, a benzoselenazole, a naphthoselenazole, a benzimidazole, a naphthoimidazole, a pyridine or a quinoline ring, wherein said heterocyclic ring may have a substituent; R₁ and R₂ are independently an optionally substituted alkyl, alkenyl or aryl group; R₃ is a hydrogen atom, a methyl group or an ethyl group; X₁ is an anion and is I, or 0 if at least one of R₁ and R₂ contains an anion; with a color developer solution containing an aromatic primary amine color developing agent for at most 90 seconds in the presence of at least one hydroxylamine derivative represented by general formula [II] or a water soluble acid salt thereof;
(wherein, R₂₁ and R₂₂ are independently a hydrogen atom and an unsubstituted or substituted alkyl group having 1 to 4 carbon atoms, especially the latter, more especially an ethyl .group, provided that R₂₁ and R₂₂ may be combined with each other to complete a nitrogen-containing ring); and at least one nitrogen-containing heterocyclic mercapto-compound.
US-A-4252892 and Research Disclosure 16480121 page 61 disclose the antioxidant preservative properties of various hydroxylamine derivatives. FR-A-1080483 and FR-A-1210904 disclose that certain nitrogen containing heterocyclic mercapto compounds have antifoggant properties. US-A-3752670 discloses the use of such heterocyclic mercapto compounds to improve the photographic recordal of objects submerged in water.
Heterocyclic rings expressed by Z₁ and 2₂ in said general formula [I] preferably include a thiazole, a benzothiazole, a naphthothiazole ring, a selenazole, a benzoselenazo and a naphthoselenazo ring more preferably a thiazole, a bensothiazole, a selenazole, a benzoselenazole or a naphthoselenazole ring, and most preferably a benzothiazole ring.
These rings may be substituted by various substituents, preferably one or more halogen atoms, hydroxyl groups, cyano groups, aryl groups, alkyl groups, alkoxy groups or alkoxycarbonyl groups, more preferably halogen atoms, cyano groups, aryl groups, C, to C₆ alkyl groups or C, to C₆ alkoxy groups, and most preferably halogen atoms, cyano groups, methyl groups, ethyl groups, methoxy groups and ethoxy groups.
R₁ and R₂ are alkyl groups, alkenyl groups or aryl groups. However, alkyl groups expressed by R₁ and R₂ are preferably C₁ to C₆ alkyl groups, and most preferably an ethyl group, a propyl group or a butyl group. These alkyl groups may be substituted by various kinds of substituent, preferably a carboxylic group and a sulfonic group i.e. R₁ and R₂ are carboxyalkyl or sulfoalkyl. In this case, salts may be formed e.g. with alkaline metal ions and an ammonium ion. At least one of R₁ and R₂ is preferably an alkyl group substituted by a sulfonic group. The alkenyl groups include an allyl group while the aryl groups include a phenyl group.
R₃ is a hydrogen atom, a methyl group or an ethyl group, preferably a hydrogen atom.
X is an anion, preferably a chloride ion, a bromide ion, an iodide ion or a p-toluene sulfonic acid ion.
l is an integer of 1. In addition, l is 0 in the event that at least one of R₁ and R₂ is a group having a minus electric charge itself such as a carboxylic group and a sulfonic group.
Typical examples of a sensitizing dye expressed by the general formula [I] are given below.
The sensitizing dye expressed by said general formula [I] according to the present invention can be easily synthesized in accordance with methods disclosed in for example British patent 660,408 and USP 3,149,105.
In order to add the sensitizing dye expressed by said general formula [I] to a silver halide emulsion, the sensitizing dye is preferably dissolved in an organic solvent, such as methanol and ethanol, which can be optionally blended with water.
The sensitizing dye may be added at any step in the process of manufacturing an emulsion, preferably in the chemical ageing step. In addition, the quantity of the sensitizing dye to be added is dependant upon the nature of the sensitizing dye and the nature of the silver halide emulsion but the sensitizing dye is preferably added in an amount of 0.01 to 0.5 g per mol of silver halide.
Although the hydroxyl amine derivatives used in the present invention are preferably added to the color developer solution, a system, in which the hydroxyl amine derivative is previously incorporated in the sensitive material and the hydroxyl amine derivative of the present invention is supplied in the color developer by continuously processing the sensitive material, is also possible.
The hydroxyl amine derivative represented by general formula [II] includes, as preferable examples, those compounds listed below:
The hydroxylamine derivative can be used in the form of an acid salt such as a hydrochloride, sulfate, p-toluenesulfate, oxalate, phosphate or acetate.
Preferred hydroxylamine derivatives include N,N-dimethylhydroxylamine, N,N-diethylhydroxylamine, N,N-dipropylhydroxylamine and N,N-dibutylhydroxylamine, and water soluble acid salts thereof.
The hydroxyl amine derivative or acid salt thereof is typically used in an amount of 0.5 to 50 g, preferably 1 to 20 g, based on one liter of the color developer. In addition, although the above described hydroxylamine derivative can be used together with hydroxylamine salts as far as the effects of the present invention are not spoiled, the latter is typically added in an amount of 1 g or less, preferably 0.5 g or less, based on 1 liter of the color developer (calculated as NH₂0H.1/2H₂SOo).
In addition, when the hydroxylamine derivative is incorporated in the photo-sensitive material and the color developer is supplied with it by continuously processing the photo-sensitive material, the hydroxylamine is generally used in an amount of 0.05 to 5 g, preferably 0.1 to 2 g, per 1 _M ² of the photo-sensitive material.
Next, the nitrogen-containing heterocyclic mercapto compounds will be described.
Heterocyclic rings in the nitrogen-containing heterocyclic mercapto compounds used in the present invention are preferably selected from an imidazoline ring, an imidazole ring, an imidazolone ring, a pyrazoline ring, a pyrazole ring, a pyrazolone ring, an oxazoline ring, an oxazole ring, an oxazolone ring, a thiazoline ring, a thiazole ring, a thiazolone ring, a selenazoline ring, a selenazole ring, a selenazolone ring, an oxadiazole ring, a thiadiazole ring, a triazole ring, a tetrazole ring, a benzimidazole ring, a benztriazole ring, an indazole ring, a benzoxaxole ring, a benzthiazole ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, a triazine ring, an oxazine ring, a thiazine ring, a tetrazine ring, a chinazoline ring, a phthalazine ring or a polyazaindene ring (for example a triazaindene ring, a tetrazaindene ring or a pentazaindene ring).
Of the above described nitrogen-containing heterocyclic mercapto compounds, mercapto oxadiazole, mercapto thiadiazole, mercapto triazole expressed by the following general formula [III] and mercapto tetrazole are preferably used:
wherein X is a hydrogen atom, an amino group, a hydroxyl group, a hydrazino group, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, a -NHCOR₃₁ group, a -NHSO₂R₃₁ group or a -R₃₂S group; Y is a hydrogen atom, an amino group, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, a -CONHR₃₃ group, a -COR₃₄ group, a -NHCOR₃₅ group or a -NHSOzRs group; Z is a nitrogen atom, sulfur atom or oxygen atom; n is 1 when Z is a nitrogen atom and 0 when Z is an oxygen atom or a sulfur atom; and R₃₁, R₃₂, R₃₃, R₃₄. and R₃s are independently an alkyl group, an alkenyl group, a cycloalkyl group or an aryl group.
In more detail describing the general formula [III], the alkyl group expressed by X and Y is preferably one containing 1 to 18 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, an octyl group or a benzyl group. The cycloalkyl group is preferably a cyclohexyl group or a cyclopentyl group. In addition, the alkenyl group is preferably one containing 2 to 18 atoms such as an allyl group or an octenyl group. The aryl group is, for example, a phenyl group or a naphthyl group.
Furthermore, the alkyl group expressed by R₃₁, R₃₂, R₃₃, R₃₄ and R₃₅ is preferably a linear or branched alkyl group containing 1 to 18 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group and a hexyl group. The cycloalkyl group is preferably a cyclopentyl group or a cyclohexyl group. The alkenyl group is preferably one containing 2 to 18 carbon atoms such as an allyl group, an octenyl group and an octadecenyl group. The aryl group is preferably a phenyl group or a naphthyl group.
The alkyl groups, cycloalkyl groups, alkenyl groups and aryl groups expressed by said X, Y, R₃₁, R₃₂, R₃₃, R₃₄ and R₃₅ may have a substituent. Such a substituent may be, for example, an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, a halogen atom, nitro group, cyano group, mercapto group, an amino group, a carboxyl group or a hydroxyl group.
The compounds expressed by the general formula [III] show the following isomerization. The present invention includes also these isomers.
Specific examples of the compounds expressed by the general formula (III] are given below.

(General formulae 111-1 to III-60)

Said compounds have been generally known and disclosed in ,for example, Japanese Patent Unexamined Publication No. 107129/ 1976, Japanese Patent Unexamined Publication No. 102621/1973, Japanese Patent Unexamined Publication No. 59463/1980, Japanese Patent Unexamined Publication No. 124333/1984 and BP 1,204,623.
The following heterocyclic mercapto compounds of formula (IV) can also be mentioned as preferable examples.
The above-mentioned exemplified compounds of formula (IV) can be synthesized in the light of, for example, J. Chem. Soc. [49], 1748 (1927); J. Org. Chem. [39], 2469(1965); Japanese Patent Unexamined Publication Nos. 89034/1975, 79436/1980, 102639/1976, 594635/1980; Ann. Chem. 44-3, 1954; Japanese Patent Publication No. 28496/1965; Chem. Ber. [20], 231(1887); USP 3,259,976; Chemical and Pharmaceutical Bulletin (Tokyo) [26], 314(1978); Berichte der Deutschen Chemischen Gesellschaft [82], 121(1948); USP 2,843,491; USP 3,017,270; British Patent 940,169 and Journal of American Chemical Society [44], 1502-1510.
It is specially noted that the use of the above-mentioned heterocyclic mercapto compound in a photo-sensitive material comprising a photo-sensitive silver halide emulsion containing silver halide grains which consist essentially of silver chloride in combination with the sensitizing dye of formula [I] has the advantage that occurrence of fog can be restrained effectively even in the case where the possibility of contamination of the bleach-fixing solution with a color developer solution carried in from a previous step is increased and the pH value thereof tends to increase when a photo-sensitive material undergoes a bleach-fixing process immediately after a color development process.
Among those exemplified hereinabove, the use of mercapto terazole compounds such as (IV-14) thru (IV-21) is especially preferable.
These nitrogen-containing heterocyclic mercapto compounds may be added to either the color developer or the sensitive material but it is preferable to add them to the sensitive material. In the event that they are added to the color developer, they are suitably added at a ratio of 10-⁶ to 10-4- mol based on 1 liter of the color developer.
The nitrogen-containing heterocyclic mercapto compounds can be added to a sensitive silver halide emulsion layer or a non-sensitive constituent layer but it is preferable to add the nitrogen-containing heterocyclic compound to a sensitive silver halide emulsion layer.
Two or more such nitrogen-containing heterocyclic mercapto compounds may be added and they may be added to two or more different layers. These nitrogen-containing heterocyclic mercapto compounds are suitably used at a ratio of 10-⁸ to 10-4- mol/m², preferably 10-⁷ to 10-⁵ mol/m².
Furthermore, the nitrogen-containing heterocyclic mercapto compounds may be added in the form of alkali metal salts such as a sodium salt, a potassium salt or a lithium salt.
The fog-preventing effect by the combination of said sensitizing dye expressed by the general formula [I] with said nitrogen-containing heterocyclic mercapto compounds in a method of forming a dye image according to the present invention can reduce not only fog of a silver halide emulsion layer containing silver halide particles spectrally sensitized with said sensitizing dye but also that of other silver halide emulsion layers. This cannot be easily anticipated from the prior art.
The silver halide particles used in the present invention may be formed of, for example, silver chloride, silver bromide, silver iodide, silver chloro-bromide, silver iodo-bromide or silver chloro-iodide, preferably silver chloro-bromide, and particularly preferably silver chloro-bromide containing silver chloride at a ratio of 10 or more mol%.
The average particle diameter of said single dispersive silver halide particles is not especially limited but it should generally be 1.0 _Ilm or less, preferably 0.8 u.m or less.
The silver halide particles used in the present invention may have regular shapes, such as cubic shape and octahedral shape, and irregular shapes such as sharp shapes.
The silver halide emulsion of the sensitive silver halide emulsion layer may be doped with platinum, palladium, iridium, rhodium, ruthenium, bismuth, cadmium or copper, for example.
Furthermore, this silver halide emulsion can be chemically sensitized. Specifically, it can be sensitized by sulfur sensitizing agents, such as allylthiocarbamides, N, N-diphenyl thiourea, sodium thiosulfate and cystine, noble metal sensitizing agents, such as gold compounds, palladium compounds, platinum compounds, ruthenium compounds, rhodium compounds and iridium compounds, or combinations thereof. Also, it can be sensitized by reducing agents such as stannous chloride.
The binder used in the constituent layer of the silver halide photo-sensitive material is most generally formed of gelatine such as alkali-treated gelatine or acid-treated gelatine. Also, a part of this gelatine can be used together with, say, gelatine derivatives, such as phthalized gelatine and phenylcarbamoylgelatine, albumin, agar-agar, Arabian rubber, alginic acid, partially hydrolyzed cellulose derivatives, partially hydrolyzed polyvinyl acetate, polyacrylamide, polyvinylalcohol, polyvinylpyrolidone and copolymers of these vinyl compounds.
The silver halide photo-sensitive material is subjected to the color developing process after the imagewise exposure to form the dye image. Particularly useful color developing agents used in the color developer include N, N-diethyl-p-phenylene diamine hydrochloride, N-methyl-p-phenylene diamine hydrochloride, N, N-dimethyl-o-phenylene diamine hydrochloride, 2-amino-5-(N-ethyl-N-dodecylamino)-toluene, N-ethyl-N-β-methane sulfonamide ethyl-3-methyl-4-aminoanilin sulfate, N-ethyl-N-0-hydrox- ylethylaminoanilin sulfate, 4-amino-3-methyl-N, N-diethylaniline hydrochloride, N-ethyl-N-,e-hydroxylethyl-3-methyl-4-aminoaniline sulfate and N-ethyl-N-methoxyethyl-3-methyl-4-aniline-p-toluene sulfonate.
These color developing agents can be used singly or in the form of mixtures of two or more. The concentration of the color developing agents is suitably selected within the range of 0.01 to 0.05 mol based on 1 liter of the color developer.
The color developer can comprise various kinds of additive in addition to said color developing agent and said hydroxylamine derivative as the preservative. For example, alkali agents such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium meta-borate and tertiary potassium phosphate, pH-buffer agents such as sodium hydrogen phosphate, potassium bihydrogen phosphate, bisodium hydrogen phosphate and potassium bicarbonate, organic solvents such as methanol and ethylene glycol triethanol amine and can be used. It is preferable that benzyl alcohol as the coloring capacity-improving agent is not present in the color developer according to the present invention. However, it can be present in a slight amount.
Benzyl alcohol may be present in the color developer in an amount of, say, 0 to 5 ml, preferably 0 to 3 ml, per liter of the color developer.
It is particularly preferable for increasing the preservative capacity of the color developer that the color developer comprises a small amount of sulfite, such as sodium sulfite or potassium sulfite, in combination with said hydroxylamine derivative. The sulfites are typically used in an amount of 0.05 to 2 g, preferably 0.1 to 0.3 g, per I liter of the color developer.
The color developer can comprise known development-inhibitors. Such development-inhibitors include bromides, such as sodium bromide and potassium bromide, chlorides, such as potassium chloride and sodium chloride, and organic development-inhibitors, such as benztriazole and benzimidazole.
The effects of the present invention are particularly remarkable where the concentration of the color developer according to the present invention is about 0.005 mol or more. In particular, in the case where the concentration of the color developer is 0.01 mol or more, the effect of the present invention, that is to say the effect of inhibiting the generation of fog due to speedy processing in the event that hydroxylamine derivative is used, is remarkably increased. Here, by "speedy processing" is meant processing in which the color development processing time is 90 seconds or less. The temperature of the color developer is generally set at 20 to 50 C, preferably 30 to 40 C.
In the speedy processing method according to the present invention it is necessary to remove undeveloped silver halide and developed image silver by a bleach-fixing process after the formation of the colored image by the color development.
The bleach-fixing time is typically set at 90 seconds or less, preferably 60 seconds or less.
The bleach used in the bleach-fixing solution includes metal complexes of organic acids in which metallic ions, such as iron ions, cobalt ions and copper ions, are coordinated with organic acids such as polycarboxylic acids, polyaminocarboxylic acids, oxalic acid and citric acid. The most preferable organic acids are polycarboxylic acids and polyaminocarboxylic acids. These polycarboxylic acids may be used also in the form of an alkali metal salt, ammonium salt or water soluble amine salt, for example. Concrete examples of these include the following compounds:

(1) ethylene diamine tetraacetic acid
(2) diethylene triamine pentaacetic acid
(3) ethylenediamine-N-(,B-oxyethyl)-N, N', N'-triacetic acid
(4) propylene diamine tetraacetic acid
(5) nitrilotriacetic acid
(6) cyclohexane diamine tetraacetic acid
(7) iminodiacetic acid
(8) dihydroxyethylglycin citric acid (or tartaric acid)
(9) ethyletherdiamine tetraacetic acid
(10) glycoletherdiamine tetraacetic acid
(11) ethylene diamine tetrapropionic acid
(12) phenylene diamine tetraacetic acid
(13) ethylene diamine tetraacetic acid disodium salt
(14) ethylene diamine tetraacetic acid tetra (trimethylammonium) salt
(15) ethylene diamine tetraacetic acid tetrasodium salt
(16) diethylene triamine pentaacetic acid pentasodium salt
(17) ethyienediamine-N-(j8-oxyethyi)-N, N', N'-triacetic acid sodium salt
(18) propylene diamine tetraacetic acid sodium salt
(19) nitriloacetic acid sodium salt
(20) cyclohexane diamine tetraacetic acid sodium salt

These bleaches are suitably used in an amount of 5 to 450 g/liter, preferably 20 to 250 g/liter.
The bleach-fixing solution may comprise sulfites as preservatives in addition to said bleaches if necessary. In addition, the bleach-fixing solution may comprise an ethylene diamine tetraacetic acid iron (III) complex salt bleach and halides such as ammonium bromide.
Said halides include hydrochloric acid, hydrobromic acid, lithium bromide, sodium bromide, potassium bromide, sodium iodide, potassium iodide and ammonium iodide in addition to ammonium bromide.
The silver halide-fixing agents used in the bleach-fixing solution include compounds which react with silver halide to form water soluble complex salts, used in the usual fixing process, typically thiosulfates, such as potassium thiosulfate, sodium thiosulfate and ammonium thiosulfate, thiocyanates, such as potassium thiocyanate, sodium thiocyanate and ammonium thiocyanate, thiourea and thioether. These fixing agents are typically used in an amount of 5 g/liter or more but in a quantity at which they can be dissolved, in general in an amount of 25 to 250 g/liter.
In addition, the bleach-fixing solution can comprise various kinds of pH-buffer agent, such as boric acid, borax, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, acetic acid, sodium acetate and ammonium hydroxide, singly or in combination. Furthermore, the bleach-fixing solution can comprise various kinds of fluorescent whitening agent, anti-foamant or surfactant. The bleach-fixing solution can comprise bisulfite-addition products of hydroxylamine, hydrazine and aldehyde compounds, preservatives such as N, N-dialkyl-hydroxylamine, organic chelating agents such as polyaminocarboxylic acids, stabilizers such as nitroalcohol and nitrates, organic solvents such as methanol, dimethylsulfonamide and dimethylsulfoxide according to circumstance.
The bleach-fixing solution can comprise various kinds of bleach-accelerator such as disclosed in Japanese Patent Unexamined Publication No. 280/1971, Japanese Patent Examined Publication No. 8506/1970, Japanese Patent Examined Publication No. 556/1971, Belgian Patent 770,910, Japanese Patent Examined Publication No. 8836/1970, Japanese Patent Examined Publication No. 9854/1978, Japanese Patent Unexamined Publication No. 71634/1979 and Japanese Patent Unexamined Publication No. 42349/1974.
The pH of the bleach-fixing solution is typically at 5.0 to 9.0, preferably 5.5 to 8.5.
Various kinds of process, such as color development and bleach-fixing (or bleaching and fixation), and furthermore washing, stabilization and drying carried out in case of need, of the silver halide color photo-sensitive material can be carried out at temperatures of, say, 25 ^*C or more, preferably 30°C or more, in order to speed-up the process.
The silver halide photo-sensitive material may be subjected to washing-substitute stabilizing treatments disclosed in e.g. Japanese Patent Unexamined Publication No. 14834/1983, Japanese Patent Unexamined Publication No. 105145/1983, Japanese Patent Unexamined Publication No. 134634/1983, Japanese Patent Unexamined Publication No. 18631/1983, Japanese Patent Application No. 2709/1983 and Japanese Patent Application No. 89288/1984.
Preferred embodiments of the present invention are described below.

EXAMPLE 1

The following layers were coated in turn on a titanium dioxide-containing polyethylene side of a support member obtained by laminating polyethylene on one side of a paper support member of 170 g/m² and laminating polyethylene containing anatase type titanium dioxide in an amount of 11% by weight on the other side of the paper support member to form silver halide color photo-sensitive materials No. 1 to 25.
The addition quantity is expressed as a quantity per 1 m² in so far as it is not specially mentioned otherwise.
The layer 1 - - - comprising 1.9 g of gelatin, 0.39 g of (based on silver) blue light-sensitive silver chloro- bromide emulsion (Note-1), 1.2 x 10 mol of a yellow coupler Y-1, the following photo-stabilizer STB-1 (0.3 g), 0.05 g of the following color contamination-inhibitor (HQ-1), 0.50 g of di-(2-ethylhexyl) phthalate (hereinafter referred to as DOP) and mercapto compounds as shown in Table 1 (0.08 g/m²).
The layer 2 - - - an intermediate layer comprising 0.7 g of gelatine, 15 mg of an irradiation-inhibiting dye (AI-1) and 0.05 g of DOP, in which 10 mg of (AI-2) and 0.05 g of said color contamination-inhibitor HQ-1 are dissolved.
The layer 3 - - - comprising 1.25 g of gelatine, 0.22 g of green light-sensitive silver chloro-bromide emulsion (containing silver chloride in an amount of 70% by mol), 0.30 g of DOP, in which 0.45 g of the following magenta coupler (M-1) is dissolved, and 0.02 g of HQ-1.
The layer 4 - - - comprising 1.2 g of gelatine, 0.08 g of HQ-11 and 0.35 g of DOP, in which 0.5 of ultraviolet absorbent (UV-1) is dissolved.
The layer 5 - - - comprising 1.4 g of gelatine, 0.20 g of red light-sensitive silver chloride emulsion, 0.20 g of DOP, in which 0.45 g of the following cyan coupler (C-1) is dissolved, and 0.02 g of HQ-1.
The layer 6 - - - comprising 1.0 g of gelatine and 0.20 g of DOP, in which 0.30 g of UV-1 is dissolved.
The layer 7 - - - comprising 0.5 g of gelatine.
In addition, 0.4 g of 2, 4-dichloro-6-hydroxy-s-triazine sodium as film-setting agent was added to said layer 4 and said layer 7, respectively, immediately before the application thereof.
(Note 1) Blue light-sensitive silver chloro-bromide emulsion.
Silver chloro-bromide emulsion containing silver chloride in an amount of 90% by mol was chemically ripened until the optimum sensitivity point to sodium thiosulfate and then spectrally sensitized by the use of sensitizing dyes as shown in Table 1 (at a ratio of 5 x 10-³ mol per 1 mol of silver halide).

Formulae (Y-1) to UV-1

Each of said sensitive materials No. 1 to No. 25 was exposed to a white light through an optical wedge and then subjected to the following processes:
The compositions of the color developer and the bleach-fixing solution are as follows:
[Composition of the color developer]
After adding pure water to 1 liter the pH is adjusted to 7.0 with diluted sulfuric acid.
The reflective concentration of a blue monochromatic light was measured for each of the resulting samples. The sensitivity was measured from the characteristic curve [B] corresponding to the yellow dye image. The gradation and fog were measured. Fog was also measured by the use of green monochromatic light.
The obtained results are shown in Table 1.
The sensitivity is expressed as a relative sensitivity with the sensitivity obtained in the event that the sensitive material 1 was processed in accordance with the process [A] as 100. In addition, the gradation is expressed as an inclination of the characteristic curve having a reflective density of 0.5 to 1.5.
It is found from the results shown in Table 1 that with the color developer [B] using hydroxylamine as the preservative, the color density is reduced, the sensitivity being reduced and the gradation being softened regardless of the kind of sensitizing dyes and the existence of heterocyclic mercapto compounds; on the contrary, with the color developer [C] using N, N-diethylhydroxylamine as the preservative, the sensitivity is reduced and the softening of the gradation is not observed but the fog is increased.
It is found that both samples which do not contain a sensitizing dye (No. 1 to No. 5) and the samples containing the emulsion sensitized by the comparative sensitizing dye-1 (No. 6 to No. 10) exhibit an only slight effect of preventing fog by the heterocyclic mercapto compounds while the samples (No. 11 to No. 25) containing the emulsion sensitized by the sensitizing dyes [1]-7, [i]-11 and [1]-26, in particular containing the heterocyclic mercapto compounds [111]-24, [III]-40 and [III]-46 exhibit a remarkable effect of preventing fog, and furthermore, effectively prevent not only the yellow fog generated in the blue light-sensitive layer but also the magenta fog generated in the green light-sensitive layer.

EXAMPLE-2

The processes were carried out in the same manner as in EXAMPLE 1 except that the spectral sensitizing dyes used for the blue light-sensitive silver chloro-bromide emulsion used in the layer 1 were changed as shown in Table 2 (5 x 10-³ mol per 1 mol of silver halide and mercapto compounds were added to the layer 1 and the layer 3 as shown in Table 2.
The obtained samples No. 26 to No. 38 were processed in the same manner as in EXAMPLE 1 with the results as shown in Table 2.
Table 2 shows the results obtained in the cases where the samples obtained by adding the mercapto compound [III]-24, which exhibited the best effect of preventing fog in EXAMPLE 1, to the layers containing the blue light-sensitive silver chloro-bromide emulsion sensitized by the comparative sensitizing dye and the sensitizing dyes [I]-3, [1]-7 and [1]-21 and the samples obtained by adding said mercapto compound [111]-19 to the layers containing the green light-sensitive emulsion were processed with the color developers [A], [B] and [C] used in EXAMPLE 1. It is found from Table 2 that the former samples exhibit a great effect of preventing fog by using the sensitizing dye [I] together with the heterocyclic mercapto compounds [III] when processed with the color developer [C] in the same manner as in EXAMPLE 1 and furthermore a remarkable effect of preventing yellow fog in the case where the heterocyclic mercapto compounds are added to the layer 3 which is the green light-sensitive emulsion layer.
In addition, it is found that the samples obtained by adding the heterocyclic mercapto compounds partly to the layer 1 and partly to the layer 3 (the blue light-sensitive layer and the green light-sensitive layer) exhibit a great effect of preventing yellow fog and magenta fog when processed with the color developer [C].

EXAMPLE 3

The samples No. 26, No. 27, No. 35 and No. 36 used in EXAMPLE 2 were subjected to the imagewise exposure and then processed in the same manner as in the processes [B], [C].
However, in this EXAMPLE the pH of the color developers [B], [C] used in the processes [B], [C] was changed to 9.7, 10.1 and 10.5, respectively. The gradation (the inclination at a reflective concentration of 0.5 to 1.5) was determined from the characteristic curves obtianed by the measurement of the reflective concentration of the obtained samples by the use of a blue monochromatic light. The results are shown in Table 3.
It can be seen from the results shown in Table 3 that the samples sensitized by the comparative sensitizing dye exhibit considerable changes in the gradation with the change of the color developer pH due to the addition of the heterocyclic mercapto compounds. The fluctuating range of the gradation has a tendency to increase in the case [C] where N, N-diethylhydroxylamine is used as the preservative of the color developer. On the contrary, the sample No. 36 according to the present invention exhibits a slight fluctuation in the gradation with a change of pH.

EXAMPLE 4

On the reflective support used in EXAMPLE 1 the following layers were provided in order from the support to prepare silver halide color photo-sensitive materials No. 39 to 62.

Layer 1 - - - A layer comprising 1.4g of gelatin, 0.3g of blue light-sensitive silver chloro-bromide emulsion (Note 2), 1.1 x 10-³ mol of yellow coupler (Y-2), 0.3g of STB-1, 0.05g of HQ-1 and 0.5g of dinonylphthalate in which 0.1 g of N,N-diethyl-(2,5-di-t-amylphenoxy) acetamide is dissolved.
Layer 2 - - - Same as Layer 2 of EXAMPLE 1.
Layer 3 - - - A layer comprising 1.25g of gelatin, 0.3g of green light-sensitive silver chloro-bromide emulsion (Note 3), 0.4g of magenta coupler (M-1) dissolved in 0.3g of DOP, 0.2g of STB-2, 0.1 g of STB-3, and 0.02g of HQ-1.
Layer 4 - - - Same as Layer 4 of EXAMPLE 1.
Layer 5 - - - A layer comprising 1.4g of gelatin, 0.20g of red light-sensitive silver chloro-bromide emulsion (Note 4), 0.45g of cyan coupler(C-1) dissolved in 0.2g of DOP, 0.10g of STB-1 and 0.025g of HQ-1 and 0.5g of dinonylphthalate in which 0.1 g of N,N-diethyl-(2,5-di-t-amylphenoxy) acetamide is dissolved.
Layer 6 - - - Same as Layer 6 of EXAMPLE 1
Layer 7 - - - Same as Layer 7 of EXAMPLE 1

(Note-2) Blue light-sensitive silver chlorobromide emulsion:

Silver chlorobromide emulsion containing cubic silver chlorobromide crystals, said silver chlorobromide containing silver chloride (99.5 % by mol) and having an average grain size of 0.70um, was chemically ripened by the use of sodium thiosulfate and potassium choloroaurate to an optimum sensitivity point. Thereafter, 5 x 10-³ mol per 1 mol of silver halide of a sensitizing dye given in Table 4 and 2 x 10^-4 mol per 1 mol of silver halide of the mercapto compound given in Table 4 were added to the emulsion.

[Note-3) Green light-sensitive silver chlorobromide emulsion:

Silver chlorobromide emulsion containing cubic silver chlorobromide crystals, said silver chlorobromide containing silver chloride (99.1 % by mol) and having an average grain size of 0.40µm, was chemically ripened by the use of sodium thiosulfate and potassium choloroaurate to an optimum sensitivity point. Thereafter, 3 x 10-³ mol per 1 mol of silver halide of a sensitising dye (GSD-1) given hereinbelow and 2.5 x 10^-4 mol per 1 mol of silver halide of the mercapto compound given in Table 4 were added to the emulsion.

(Note-4) Red light-sensitive silver chlorobromide emulsion:

Silver chlorobromide emulsion containing cubic silver chlorobromide crystals, said silver chlorobromide containing silver chloride at a ratio of 99.6 % by mol and having an average grain size of 0.42µ, m, was chemically ripened by the use of sodium thiosulfate and potassium choloroaurate to an optimum sensitivity point. Thereafter, 0.8 x 10-⁴ mol per 1 mol of silver halide of a sensitizing dye (RSD-1) given hereinbelow and 2.5 x 10-⁴ mol per 1 mol of silver halide of the mercapto compound given in Table 4 were added to the emulsion.
The photo-sensitive materials thus obtained were subjected to white exposure through an optical wedge and, thereafter, to the following processes:
The compositions used of the color developer with respect to the processes are as follows:
Add water to make a total volume of 1 liter and adjust pH to 10.0.
As bleach-fixing solution the following were used with reference to the respective processes: [D] and [F]
The same bleach-fixing solution as used in Example 1 was used except that this solution did not contain color developer and the pH was adjusted to 6.2. [E]
The bleach-fixing solution used for process [D] and the color developer used for [E] were mixed at a ratio of 1:1 and pH thereof was adjusted to 7.0. [G]
The bleach-fixing solution used for process [D] and the color developer used for [F] were mixed at a ratio of 1:1 and the pH thereof was adjusted to 7.0.
The reflective density measurement of the respective samples were carried out and sensitivity, gradation and fog of the respective samples were obtained from the characteristic curves thereof.
The results are shown in Table 4. In the table sensitivity is expessed in terms of a relative sensitivity when the sensitivity of Comparative Sample 39 with the process [F] is made 100.
It is apparent from the results shown in Table 4 that fog can be restrained effectively in the samples in which exemplified mercapto compounds III-24, IV-14 and IV-20 in combination with a blue dye sensitizer of the present invention are employed (Samples Nos. 48, 49, 50, 54, 55, 56, 60, 61 and 62), in respective cases when they are processed with either [D],[E], [F] or [G]. In comparison thereto, with respect to those samples in which either one of sensitizing dye or mercapto compound outside the scope of the invention is used (Samples Nos. 39, 40, 41, 45, 46, 47, 51, 52, 53, 57, 58 and 59], although occurrence of fog is relatively low when these samples were processed with [D], increase in fog was observed when N,N-diethylhydroxylamine was employed as the preservative (in process [F]) and this tendency was further amplified in process [G] due to contamination by color developer.
In accordance with the present invention, occurrence of fog can be effectively restrained even in the process [G] and this effect was found to be particularly good when a mercapto tetrazole compound such as IV-14 or IV-20 is employed.

EXAMPLE 5

Samples 63 thru 86 were prepared respectively in the same manner as Samples 39 thru 62 in EXAMPLE 4, except that in the samples of this EXAMPLE half the amount of mercapto compound used in layer 1 of the respective samples in EXAMPLE 3 was added to layer 2.
The samples thus prepared were processed in the same manner as in EXAMPLE 4, with the proviso that, in this EXAMPLE, 10g per 1 liter of color developer of 11-25 was used in place of 11-3 as a preserver for the color developer.
The results are shown in Table 5.
It is apparent from the table that a similar effect to that obtained in EXAMPLE 4 can also be obtained in the case where 11-25 is employed as the preserver for the color developer.

Claims

1. A method of processing a light-sensitive silver halide color photographic material which comprises processing an imagewise exposed light-sensitive silver halide color photographic material comprising a support bearing at least one silver halide emulsion layer containing silver halide grains which are sensitized with a sensitizing dye of formula [I]:

wherein:

Z₁ and Z₂, which may be identical or different, are each a group which, together with the nitrogen and carbon atoms to which they are attached, form a substituted or unsubstituted heterocyclic ring which is a thiazole, a benzothiazole, a selenazole, a benzoselenazole, a naphthoselenazole, a benzimidazole, a naphthoimidazole, a pyridine or a quinoline ring;

R₁, and R₂, which may be identical or different, are each a substituted or unsubstituted alkyl, alkenyl or aryl group;

R₃ is hydrogen, a methyl group or an ethyl group;

X₁ is an anion; and

l is 1, or 0 if at least one of R₁ and R₂ contains an anion

with a colour developer solution comprising an aromatic primary amine color developing agent for at most 90 seconds in the presence of:

at least one hydroxylamine derivative of formula

wherein R₂₁ and R₂₂, which may be identical or different, are each hydrogen or an unsubstituted or substituted alkyl group having 1 to 4 carbon atoms, with the proviso that R₂₁ and R₂₂ are not simultaneously hydrogen, or R₂₁ and R₂₂, together with the nitrogen atom to which they are attached, form a nitrogen-containing ring, or a water soluble acid salt thereof; and

at least one nitrogen-containing heterocyclic mercapto compound.

2. A method according to claim 1 wherein Zi, and Z₂ which may be identical or different, are each a group, which together with the nitrogen and carbon atoms to which they are attached, form a substituted or unsubstituted thiazole, benzothiazole, selenazole, benzoselenazole or a naphthoselenazole ring.

3. A method according to claim 2 wherein Z_l and Z₂ are both groups which, together with the nitrogen and carbon atoms to which they are attached, form an unsubstituted or substituted benzothiozole ring.

4. A method according to any one of claims 1 to 3 wherein R_l and R₂, which may be identical or different, are each a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms.

5. A method according to claim 4 wherein Ri and R₂, which may be identical or different, are each an ethyl group, a propyl group or a butyl group.

6. A method according to any one of claims 1 to 4 wherein at least one of R, and R₂, which may be identical or different, is a carboxyalkyl group or a sulphoalkyl group.

7. A method according to any one of claims 1 to 6 wherein R₂₁ and R₂₂, which may be identical or different, are each an unsubstituted or substituted alkyl group having 1 to 4 carbon atoms.

8. A method according to claim 7 wherein R₂₁ and R₂₂ are both ethyl groups.

9. A method according to claim 7 wherein the hydroxylamine derivative is N,N-dimethylhydroxylamine, N,N-diethylhydroxylamine, N,N-dipropylhydroxylamine or N,N-dibutylhydroxylamine, or a water soluble acid salt thereof.

10. A method according to any one of claims 1 to 9 wherein the nitrogen-containing heterocyclic mercapto compound is a mercapto oxadiazole, a mercapto thiadiazole, a mercapto triazole or a mercapto tetrazole.

11. A method according to any one of claims 1 to 10 wherein the nitrogen-containing heterocyclic mercapto compound is a compound of formula [III]

wherein:

X is hydrogen, an amino group, a hydroxyl group, a hydrazino group, an optionally substituted alkyl, alkenyl, cycloalkyl or aryl group, a -NHCOR₃₁ group, -NHS0₂R₃₁ group, or a -R₃₂S group;

Y is hydrogen, an amino group, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, a -CONHR₃₃ group, a -COR₃₄ group, a -NHCOR₃₅ group, or a -NHS0₂R₃₅ group;

Z is nitrogen, sulfur or oxygen;

n is 1 when Z is nitrogen or 0 when Z is oxygen or sulfur; and

R₃₁, R₃₂, R₃₃, R₃₄ and R₃₅ are an optionally substituted alkyl alkenyl, cycloalkyl or aryl group.

12. A method according to any one of claims 1 to 11 wherein the nitrogen-containing heterocyclic mercapto compound is present in the light-sensitive silver halide photographic material.

13. A method according to claim 12 wherein the nitrogen-containing heterocyclic mercapto compound is present in the light-sensitive silver halide photographic material in an amount of from 10-⁷ to 10-⁵ mol per m² thereof.

14. A method according to claim 12 or 13 wherein the hydroxylamine compound is present in the color developer solution.