The use of a polyvalent cation-organic phosphonic acid complex as a bleaching agent
United States Patent 3928040
In a method of developing, bleaching and fixing an exposed silver halide photographic material, the improvement comprising bleaching the silver halide photographic material with a bleaching solution containing a polyvalent cation-organic phosphonic acid complex as the bleaching agent.
US Patent References:
PHOTOGRAPHIC BLIXES AND BLIXING
Stephen et al. - October 1971 - 3615508
/3706561.html
Mowrey et al. - December 1972 - 3706561
PHOTOGRAPHIC BLIXES AND BLIXING
Stephen et al. - October 1971 - 3615508
/3706561.html
Mowrey et al. - December 1972 - 3706561
Inventors:
Shimamura, Isao (Minami Ashigara, JA)
Iwano, Haruhiko (Minami Ashigara, JA)
Iwano, Haruhiko (Minami Ashigara, JA)
Application Number:
05/486737
Publication Date:
12/23/1975
Filing Date:
07/08/1974
View Patent Images:
Export Citation:
Assignee:
Fuji Photo Film Co., Ltd. (Minami Ashigara, JA)
Primary Class:
Other Classes:
430/393, 430/407, 430/460, 430/400
International Classes:
G03C5/44; G03C5/40; G03C5/32
Field of Search:
96/60,6BF
Primary Examiner:
Klein, David
Assistant Examiner:
Hightower, Judson R.
Attorney, Agent or Firm:
Sughrue, Rothwell, Mion, Zinn & Macpeak
Claims:
What is claimed is
1. In a method for developing, bleaching and fixing an image-wise exposed silver halide photographic material, bleaching and fixing comprising separate steps in said method, the improvement comprising bleaching the silver halide photographic material with a bleaching solution containing a polyvalent cation-organic phosphonic acid complex as the bleaching agent and a re-halogenating agent selected from the group consisting of an alkali metal halide and an ammonium halide.
2. The method as claimed in claim 1, wherein said polyvalent cation is Fe(III), Co, Ni or Cu(II).
3. The method as claimed in claim 1, wherein said organic phosphonic acid is an aminopolymethylene phosphonic acid or a water-soluble salt thereof.
4. The method as claimed in claim 3, wherein said aminopolymethylene phosphonic acid is represented by the following general formula (I)
5. The method as claimed in claim 4, wherein M is an alkali metal, ammonium or water-soluble substituted ammonium ion; wherein the alkyl group for R1 is a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group; wherein said aryl group for R1 is a phenyl group, an o-tolyl group, a m-tolyl group, a p-tolyl group, a p-carboxyphenyl group, or a water-soluble salt of a p-carboxyphenyl group; wherein said aralkyl group for R1 is a benzyl group, an α-phenyl group or an o-acetamidobenzyl group; wherein said alicyclic group for R1 is a cyclohexyl group or a cyclopentyl group; and wherein said heterocyclic group for R1 is a pyrrolidylmethyl group, a pyrrolidylbutyl group, a benzothiazolymethyl group or a tetrahydroquinolylmethyl group.
6. The method as claimed in claim 4, wherein R1 is an alkyl group substituted with a hydroxyl group, an alkoxyl group, a halogen atom, --PO3 M2, --CH2 PO3 M2 or --N(CH2 PO3 N2)2, wherein M represents a hydrogen atom or a cation which imparts water-solubility.
7. The method as claimed in claim 1, wherein said organic phosphonic acid is a compound respresentably the general formula (II)
8. The method as claimed in claim 7, wherein M is an alkali metal, ammonium or water-soluble substituted ammonium ion; wherein the alkyl group for R2 is a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group.
9. The method as claimed in claim 7, wherein the alkyl group for R2 is an alkyl group substituted with a hydroxyl group, an alkoxyl group, a halogen atom, --PO3 M2, --CH2 --PO3 M2 or --N(CH2 PO3 N2)2, wherein M is a hydrogen atom or a cation which imparts water-solubility.
10. The method as claimed in claim 4 wherein M is an alkali metal, ammonium or water-soluble substituted ammonium ion.
11. The method as claimed in claim 6 wherein M is an alkali metal, ammonium or water-soluble substituted ammonium ion.
12. The method as claimed in claim 7 wherein M is an alkali metal, ammonium or water-soluble substituted ammonium ion.
13. The method as claimed in claim 9 wherein M is an alkali metal, ammonium or water-soluble substituted ammonium ion.
14. The method as claimed in claim 1, wherein said aminopolymethylene phosphonic acid is selected from those represented by the following general formulae (I) or (II)
15. The method as claimed in claim 14 wherein said polyvalent cation is Fe(III), Co, Ni or Cu(II).
16. The method as claimed in claim 15 wherein M is an alkali metal, ammonium or water-soluble substituted ammonium ion.
17. The method as claimed in claim 1 wherein from about 20 to 200 g. of said polyvalent cation-organic phosphonic acid complex is present per one liter of the bleaching solution.
18. The method as claimed in claim 1 wherein said bleaching solution has a pH of about 3 to 8.
1. In a method for developing, bleaching and fixing an image-wise exposed silver halide photographic material, bleaching and fixing comprising separate steps in said method, the improvement comprising bleaching the silver halide photographic material with a bleaching solution containing a polyvalent cation-organic phosphonic acid complex as the bleaching agent and a re-halogenating agent selected from the group consisting of an alkali metal halide and an ammonium halide.
2. The method as claimed in claim 1, wherein said polyvalent cation is Fe(III), Co, Ni or Cu(II).
3. The method as claimed in claim 1, wherein said organic phosphonic acid is an aminopolymethylene phosphonic acid or a water-soluble salt thereof.
4. The method as claimed in claim 3, wherein said aminopolymethylene phosphonic acid is represented by the following general formula (I)
5. The method as claimed in claim 4, wherein M is an alkali metal, ammonium or water-soluble substituted ammonium ion; wherein the alkyl group for R1 is a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group; wherein said aryl group for R1 is a phenyl group, an o-tolyl group, a m-tolyl group, a p-tolyl group, a p-carboxyphenyl group, or a water-soluble salt of a p-carboxyphenyl group; wherein said aralkyl group for R1 is a benzyl group, an α-phenyl group or an o-acetamidobenzyl group; wherein said alicyclic group for R1 is a cyclohexyl group or a cyclopentyl group; and wherein said heterocyclic group for R1 is a pyrrolidylmethyl group, a pyrrolidylbutyl group, a benzothiazolymethyl group or a tetrahydroquinolylmethyl group.
6. The method as claimed in claim 4, wherein R1 is an alkyl group substituted with a hydroxyl group, an alkoxyl group, a halogen atom, --PO3 M2, --CH2 PO3 M2 or --N(CH2 PO3 N2)2, wherein M represents a hydrogen atom or a cation which imparts water-solubility.
7. The method as claimed in claim 1, wherein said organic phosphonic acid is a compound respresentably the general formula (II)
8. The method as claimed in claim 7, wherein M is an alkali metal, ammonium or water-soluble substituted ammonium ion; wherein the alkyl group for R2 is a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group.
9. The method as claimed in claim 7, wherein the alkyl group for R2 is an alkyl group substituted with a hydroxyl group, an alkoxyl group, a halogen atom, --PO3 M2, --CH2 --PO3 M2 or --N(CH2 PO3 N2)2, wherein M is a hydrogen atom or a cation which imparts water-solubility.
10. The method as claimed in claim 4 wherein M is an alkali metal, ammonium or water-soluble substituted ammonium ion.
11. The method as claimed in claim 6 wherein M is an alkali metal, ammonium or water-soluble substituted ammonium ion.
12. The method as claimed in claim 7 wherein M is an alkali metal, ammonium or water-soluble substituted ammonium ion.
13. The method as claimed in claim 9 wherein M is an alkali metal, ammonium or water-soluble substituted ammonium ion.
14. The method as claimed in claim 1, wherein said aminopolymethylene phosphonic acid is selected from those represented by the following general formulae (I) or (II)
15. The method as claimed in claim 14 wherein said polyvalent cation is Fe(III), Co, Ni or Cu(II).
16. The method as claimed in claim 15 wherein M is an alkali metal, ammonium or water-soluble substituted ammonium ion.
17. The method as claimed in claim 1 wherein from about 20 to 200 g. of said polyvalent cation-organic phosphonic acid complex is present per one liter of the bleaching solution.
18. The method as claimed in claim 1 wherein said bleaching solution has a pH of about 3 to 8.
Description:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method for processing photographic materials, and more precisely, to a method for bleaching of a developed silver halide photographic emulsion layer.
2. Description of the Prior Art
In the processing of some kinds of silver halide photographic materials a step for removal of developed silver from the silver halide emulsion layer (the so-called bleaching step) is included. For example, in the processing of color photographic materials such as color negative films, color reversal films and color papers, a step for the removal of silver images formed in color development is carried out in order to retain only color images formed in the color development; and analogously, in the processing of black-white reversal photographic materials a step for the removal of silver images formed in an initial exposure and development is carried out for the purpose of formation of positive images.
Ferricyanides and iron-aminopolycarboxylic acid complexes, for example, are known as bleaching agents used in these steps. These conventional bleaching agents, however, are not completely satisfactory with respect to both non-toxicity and bleaching ability, and therefore, recently, discovery of other practical photographic bleaching agents as well as photographic bleaching methods have been desired.
SUMMARY OF THE INVENTION
An object of this invention is to provide a photographic bleaching method where a less toxic bleaching agent of a high bleaching rate is used.
Another object of this invention is to provide a method of formation of color photographic images at a much reduced bleaching time.
Still another object of this invention is to provide a method for processing color photographic materials which does not give rise to pollution problems.
These objects of this invention are achieved by the use of a bleaching solution containing a polyvalent cation-organic phosphonic acid complex as the bleaching agent. More precisely, the method of this invention comprises processing an exposed and developed silver halide emulsion layer with a bleaching solution containing a polyvalent cation-organic phosphonic acid complex as the bleaching agent.
DETAILED DESCRIPTION OF THE INVENTION
As described above, a method for processing photographic materials where a polyvalent cation-aminopolycarboxylic acid complex is used as a bleaching component is already known. The method of this invention is different from this conventional method in the use of an organic phosphonic acid in place of the aminopolycarboxylic acid, which is an important factor. Accordingly, the polyvalent cations in the present invention can be interpreted as having the same meanings as those of known polyvalent cations. Various kinds of polyvalent cations which can form complexes are known in the chemical field, and one skilled in the art can easily select these cations. Of the polyvalent cations Fe(III), Co, Ni and Cu(II) are particularly useful in the method of this invention.
On the other hand, organic phosphonic acids are also well known, and aminopolymethylene phosphonic acids (or water-soluble salts thereof) are especially advantageous. Aminopolymethylene phosphonic acids can be represented by the following general formula (I):
where M represents a hydrogen atom or a cation which imparts water-solubility (e.g., an alkali metal such as sodium or potassium; ammonium, pyridinium, triethanolammonium or triethylammonium ion); R 1 represents an alkyl group having 1 to 4 carbon atoms (e.g., a methyl, ethyl, propyl, isopropyl or butyl group), an aryl group (e.g., a phenyl, o-tolyl, m-tolyl, p-tolyl or p-carboxyphenyl group or a water-soluble salt of a p-carboxyphenyl group such as the sodium or potassium salt), an aralkyl group (e.g., benzyl, β-phenethyl or o-acetamidobenzyl group, especially an aralkyl group having 7 to 9 carbon atoms), an alicyclic group (e.g., a cyclohexyl or cyclopentyl group), or a heterocyclic group (e.g., a pyrrolidylmethyl, pyrrolidylbutyl, benzothiazoylmethyl or tetrahydroquinolylmethyl group), and R 1 (especially when representing an alkyl group) can be substituted with a hydroxyl group, an alkoxy group (e.g., a methoxy or ethoxy group), a halogen atom (e.g., a chlorine atom), --PO 3 M 2 , --CH 2 PO 3 M 2 or --N(CH 2 PO 3 M 2 ) 2 , where M has the same meaning as described above.
Representative examples of these phosphonic acids of the general formula (I) are given below.
Ethylenediamine-N,N,N',N'-tetramethylene phosphonic acid
Nitrilo-N,N,N-trimethylene phosphonic acid
1,2-Cyclohexanediamine-N,N,N',N'-tetramethylene phosphonic acid
o-Carboxyaniline-N,N-dimethylene phosphonic acid
Propylamine-N,N-dimethylene phosphonic acid
4-(N-Pyrrolidino)butylamine-N,N-bis(methylene phosphonic acid)
1,3-Diaminopropanol-N,N,N',N'-tetramethylene phosphonic acid 1,3-Propanediamine-N,N,N',N'-tetramethylene phosphonic acid
1,6-Hexanediamine-N,N,N',N'-tetramethylene phosphonic acid
o-Acetamidobenzylamine-N,N-dimethylene phosphonic acid
o-Toluidine-N,N-dimethylene phosphonic acid
2-Pyridylamine-N,N-dimethylene phosphonic acid
Other examples of organic phosphonic acids are compounds represented by the following general formula (II):
where R 2 represents a hydrogen atom, or an alkyl, aralkyl, alicyclic or heterocyclic group which is defined above, or --PO 3 M 2 ; and R 3 represents a hydrogen atom, a hydroxyl group or an alkyl group, or the above defined substituted alkyl group or --PO 3 M 2 , where M has the same meaning as described above. Representative examples of compounds of the above general formula (II) are given below.
1-Hydroxyethylidene-1,1-diphosphonic acid
Ethylidine-1,1,1-triphosphonic acid
1-Hydroxy-2-phenylethylidene-1,1-diphosphonic acid
These organic phosphonic acids are described in U.S. Pat. No. 3,617,282.
The bleaching solution used in the present invention contains as a bleaching agent the above specified polyvalent cation-organic phosphonic acid complex. The amount of this complex is generally about 20 to 200 g, preferably 50 to 150 g, per 1 liter of the bleaching solution. The lower limit of the amount of complex depends upon the bleaching ability thereof, and the upper limit thereof mainly depends upon factors such as solubility and economics. Accordingly, the upper limit of the amount of the complex can be extended further by the use of an appropriate dissolution aid, and so, the upper limit thereof is not limited to within the above mentioned scope. In the present invention it is only important that the bleaching solution contain the above described complex, and therefore, the method of addition thereof can be broadly. In general, a convenient method comprises adding a complex which was previously prepared to an aqueous solution, but apart from this, it also is possible to form the complex in an aqueous solution by adding a salt of poly-valent cation and an organic phosphonic acid to the aqueous solution. In the latter case, the amount of both compounds added are so determined that the above-described amount of complex is formed.
The bleaching solution can contain various kinds of photographic additives, and in particular, the solution preferably contains a re-halogenating agent. Examples of re-halogenating agents include an alkali metal halide (especially an alkali metal bromide) and an ammonium halide (especially ammonium bromide), and representative examples of these halides are, for example, potassium bromide, sodium bromide, sodium chloride and ammonium bromide. The content of the re-halogenating agent generally used is about 20 to 300 g, preferably 50 to 200 g, per 1 liter of the bleaching solution.
In addition, the bleaching solution of this invention can further contain other additives known in this technical field as being capable of being added to a bleaching solution or a bleaching-fixation solution. Such additives include nitrates such as sodium nitrate, sulfites such as sodium sulfite, mercapto compounds such as mercaptotriazole, pH buffers such as borates, oxalates, acetates, carbonates, phosphates, stain-inhibitors such as formamidinosulfinic acid, polyamine compounds as described, for example, in U.S. Pat. No. 3,578,454, alkylamine compounds as described, for example, in U.S. Pat. No. 3,578,453, polyethyleneoxides as described, for example, in German Pat. No. 966,410, and nitrogen containing heterocyclic compounds as described, for example, in German Pat. No. 1,290,812.
A suitable pH for the bleaching solution of this invention is a pH of about 3 to 8, preferably 5 to 7.
The method of this invention comprises the individual steps of development, bleaching and fixation. The development is generally color development, but development also means black-white development or black-white development and color development. the above-described three steps need not be necessarily carried out without interruption, and other additional steps can be carried out before and after each of these steps. Such additional steps include subjecting the photographic material to a fixation bath, an image stabilization bath, a hardening bath, a neutralization bath, a water-washing (including rinsing), etc., and, as the case may be, the bleaching and fixation step can further be included.
The color developer used in the present invention is an alkaline aqueous solution of a known aromatic primary amine color developing agent, and preferably contains 1 g/liter or more, or as the case may be, less than 1 g/liter, of benzyl alcohol. Representative examples of color developing agents are phenylenediamine derivatives such as N,N-diethyl-p-phenylenediamine sulfate, 4-amino-N-ethyl-N-β-hydroxyethylaniline sulfate, 3-methyl-4-amino-N-ethyl-β-methanesulfoamidoethylaniline-se squisulfat emonohydrate, 3-methyl-4-amino-N-ethyl-N-β-hydroxyethylaniline sulfate, 3-methyl-4-amino-N,N-diethylaniline chloride, etc. In addition, the color developer can contain known developer additives such as alkali metal sulfites, carbonates, bisulfites, bromides, iodides as well as anti-fogging agents, development accelerating agents and solvents such as diethylene glycol.
When color photographic material which do not contain a color coupler are developed, the color developer contains a color coupler (for example, as described in U.S. Pat. Nos. 2,252,718; 2,592,243 and 2,590,970).
On the other hand, when the method of this invention is applied to black-white development, an alkaline aqueous solution is used as a developer, containing developing agents such as the dihydroxybenzenes (e.g., hydroquinone, chlorohydroquinone, bromohydroquinone, isopropylhydroquinone, toluhydroquinone, methylhydroquinone, 2,3-dichloro-hydroquinone, 2,5-dimethyl-hydroquinone), the 3-pyrazolidones (e.g., 1-phenyl-3-pyrazolidone, 1-phenyl-4,4-dimethyl-3-pyrazolidone, 1-phenyl-4-ethyl-3-pyrazolidone, 1-phenyl-5-methyl-3-pyrazolidone), the aminophenols (e.g., o-aminophenol, p-aminophenol, N-methyl-o-aminophenol, N-methyl-p-aminophenol, 2,4-diaminophenol), pyrogallol, ascorbic acid, the 1-aryl-aminopyrazolines (e.g., 1-(p-hydroxyphenyl)-3-aminopyrazoline, 1-(p-methylaminophenyl)-3-aminopyrazoline, 1-(p-aminophenyl)-3-aminopyrazoline, 1-(p-amino-m-methylphenyl)-3-aminopyrazoline) or a mixture thereof. The pH of each of these black-white developers and color developers is about 9 to 13, preferably 10 to 12.5.
In the fixation step carried out after the bleaching step, each and every conventional fixing solution can be used. A suitable description thereof appears in U.S. Pat. No. 3,582,322. More precisely, about 50 to 200 g/liter or so of ammonium, sodium or potassium thiosulfate can be used as a fixing agent, and additionally, a stabilizer such as sulfite or metabisulfite, a hardening agent such as potassium alum, and a pH buffer such as acetate or borate can also be contained in the fixing solution. The fixing solution has a pH value of about 3 to 10.
Photographic materials to which the method of this invention can be applied contain at least one silver halide emulsion layer. The silver halide emulsion is prepared by dispersing a silver halide such as silver chloride, silver iodide, silver bromide, silver bromochloride, silver bromoiodide, or silver bromoiodochloride, in a hydrophilic colloid (binder).
Representative examples of hydrophilic colloids are, for example, galatin, colloidal albumin, casein, cellulose derivatives such as carboxymethyl cellulose and hydroxyethyl cellulose, saccharide derivatives such as agar, sodium alginate and starch derivatives, and synthetic hydrophilic colloids such as polyvinyl alcohol, poly-N-vinyl pyrrolidone, polyacrylic acid copolymers, polyacrylamide and derivatives thereof. If desired, a compatible mixture of two or more of these colloids can be used. Of these colloids the most common one is gelatin, and a part or all of the gelatin can be replaced by synthetic high molecular weight substances. In addition, the gelatin can also be substituted by the so-called gelatin derivatives (that is, those prepared by treating the functional groups contained in the molecule such as amino groups, imino groups, hydroxy groups or carboxyl groups, with an agent having one group capable of reacting with these functional groups) or by gelatin graft-polymers grafted with molecular chains of other high molecular weight substances. Representative examples of agents for preparing gelatin derivatives are, for example, the isocyanates, acid chlorides and acid anhydrides as described in U.S. Pat. No. 2,614,928; the acid anhydrides described in U.S. Pat. No. 3,118,766; the bromoacetic acids described in Japanese Pat. Publication No. 5514/64; the phenylglycidylethers described in Japanese Pat. Publication No. 26845/67; the vinylsulfone compounds described in U.S. Pat. No. 3,132,945; the N-allylvinyl-sulfonamides described in British Pat. No. 861,414; the maleinimide compounds described in U.S. Pat. No. 3,186,846; the acrylonitriles described in U.S. Pat. No. 2,594,293; the polyalkyleneoxides described in U.S. Pat. No. 3,312,553; the epoxy compounds described in Japanese Pat. Publication No. 26845/67; the acid esters described in U.S. Pat. No. 2,763,639; and the alkanesultones described in British Pat. No. 1,033,189. Regarding the high molecular weight substances (i.e., the branch component) which can be grafted on gelatin, a number of substances are disclosed, for example, in U.S. Pat. No. 2,763,625, No. 2,831,767 and No. 2,956,884, and Polymer Letters 5, 594 (1967), Phot. Sci. Eng., 9, 148 (1965), and J. of Polymer Sci. A-1, 9, 3199 (1971), and in addition, a broad range of polymers or copolymers of the so-called vinyl monomers such as acrylic acid and methacrylic acid or esters, amides and nitriles thereof as well as styrene can also be used as such a substance. In particular, hydrophilic vinyl polymers which are compatible with gelatin to some degree, such as the polymers or copolymers of acrylic acid, acrylamide, methacrylamide, hydroxyalkyl acrylate or hydroxyalkyl methacrylate, are especially preferred.
Silver halide emulsions can be prepared using conventional techniques which are generally well known in this technical field (e.g., the single-jet process, the double-jet process, the control-jet process) where a water-soluble silver salt (e.g., silver nitrate) and a water-soluble halide are admixed in the presence of water and the hydrophilic colloid and the mixture is subjected to physical ripening and chemical ripening such as gold sensitization and/or sulfur sensitization. To the silver halide emulsion, spectral sensitizer (e.g. cyanine dyes, merocyanine dyes or mixtures thereof, for example, as disclosed in U.S. Pat. Nos. 2,493,748; 2,519,001; 2,977,229; 3,480,434; 3,672,897; 3,703,377; 2,688,545; 2,912,329; 3,397,060; 3,615,635; 3,628,964; 3,522,052; 3,527,641; 3,615,613; 3,515,632; 3,617,295; 3,635,721; 3,694,217; etc.), stabilizers (e.g., 4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene), sensitizers (e.g., the compounds described in U.S. Pat. No. 3,619,198), anti-fogging agents (e.g., benzotriazole, 5-nitrobenzimidazole, polyethyleneoxide), hardening agents (e.g., aldehyde compounds such as formaldehyde and glyoxal, nonaldehyde compounds such as mucochloric acid and 2-hydroxy-4,6-dichloro-s-triazine, for example, as described in U.S. Pat. Nos. 3,288,775; 2,732,303; 3,635,718; 3,232,763; 2,732,316; 2,586,168; 3,103,437; 3,017,280; 2,983,611; 2,725,294; 2,725,295; 3,100,704; 3,091,537; 3,321,313; 3,543,292; etc.) and coating auxiliaries (e.g., saponin, sodium lauryl sulfate, dodecylphenolpolyethyleneoxide ether, hexadecyltrimethylammonium bromide) can be added during the preparation thereof or immediately before the application thereof. The silver halides in the emulsion thus obtained preferably have an average particle size of about 0.2 to 1.5 μ.
When the method of this invention is applied to a system where a color coupler is contained in a photographic material (as disclosed in U.S. Pat. Nos. 2,376,679, 2,322,027 and 2,801,171), at least one silver halide emulsion layer can contain a color coupler (i.e., a compound forming a dye after reaction with an oxidation product of a color developing agent). In general, each of a cyan, magenta and yellow color coupler is used in color photography. Suitable examples of color couplers are described as follows: cyan couplers;
U.S. Pat. Nos. 2,474,293; 2,698,794; 3,034,892; 3,214,437; 3,253,924; 3,311,476; 3,458,315; 3,582,322; 3,591,383; etc.
magenta couplers;
U.S. Pat. Nos. 2,600,788; 2,983,608; 3,006,759; 3,062,653; 3,214,437; 3,253,924; 3,311,476; 3,337,344; 3,419,391; 3,419,808; 3,476,560; 3,582,322; etc.
yellow couplers;
U.S. Pat. Nos. 3,277,157; 3,415,652; 3,447,928; 3,311,476; 3,408,194; 2,875,057; 3,265,506; 3,409,439; 3,551,157; 3,551,156; 3,582,322; etc.
More precisely, a color coupler which has a naphthol or phenol skeleton and can form an indoaniline dye by coupling is used as a cyan coupler; a color coupler which has active methylene groups and a 5-pyrazolone ring structure sleketon is used as a magenta coupler; and a color coupler of a benzoylacetanilide, pivalylacetanilide or acrylacetanilide structure with or without a substituent in the coupling position, is used as a yellow coupler. This is because the bleaching solution of this invention has a sufficient oxidizability to increase the color density.
Representative of pyrazolone color couplers are those represented by the general formula (III) ##EQU1## wherein, R 4 represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, and R 5 represents an alkyl group, a carbamyl group, an amino group or an amido group. Examples of compounds represented by the above formula are as follows:
1-p-sec-Amylphenyl-3-n-amyl-5-pyrazolone
2-Cyanoacetyl-5-(p-sec-amylbenzoylamino)coumarone
2-Cyanoacetylcoumaron-5-(N-n-amyl-p-t-amylsulfoanilide)
2-Cyanoacetylcoumaron-5-sulfon-N-n-butylanilide
1-p-Laurylphenyl-3-methyl-5-pyrazolone
1-β-Naphthyl-3-amyl-5-pyrazolone
1-p-Nitrophenyl-3-n-amyl-5-pyrazolone
1-Phenyl-3-acetylamino-5-pyrazolone
1-Phenyl-3-n-valerylamino-5-pyrazolone
1-Phenyl-3-chloroacetylamino-5-pyrazolone
1-Phenyl-3-(m-aminobenzoyl)amino-5-pyrazolone
1-p-Phenoxyphenyl-3-(p-t-amyloxybenzoyl)amino-5-pyrazolo ne
1-(2',4',6'-Trichlorophenyl)-3-benzamido-5-pyrazolone
1-(2',4'-Dichlorophenyl)-3-[3"-(2'",4'"-di-t-amylphenoxy acetamido)benzamido ]-5-pyrazolone
1-(2,4-Dimethyl-6-chlorophenyl)-3-[3'-(2'",4'"-di-t-amyl phenoxyacetamido)be nzamido]-5-pyrazolone
In addition, the following couplers can also be used:
1-(2',4',6'-Trichlorophenyl)-3-(2"-chloro-5"-tetradecane amidoanilino)-5-pyr azolone
1-(2',4',6'-Trichlorophenyl)-3-{2"'-chloro-5"-[N-3'"-(2' ",5'"-di-t-pentylph enoxy)propyl]sulfamoylanilino}-5-pyrazolone
1-(2',4',6'-Trichlorophenyl)-3-(2"-chloro-4"-tetradecylo xy-carbonylanilino) -5-pyrazolone
1-(2',6'-Dichloro-4'-tetradecyloxycarbonylphenyl)-3-(2,4 -dichloroanilino)-5 -pyrazolone
1-(2',4',6'-Trichlorophenyl)-3-{2"-chloro-5"-[2'"-(3'"-t -butyl-4'"-hydroxyp henoxy)tetradecaneamido]anilino}-5-pyrazolone
1-(2',4',6'-Trichlorophenyl)-3-(2"-chloro-5"-tetradecane amidoanilino)-5-pyr azolone
1-(2',4',6'-Trichlorophenyl)-3-{3"-[α-2'",4'"-di-t-pent ylphenoxy)acet amido]benzamido}-5-pyrazolon-4-yl-benzyl carbonate
1-(2',4',6'-Trichlorophenyl)-3-{3"-[α-(3'"-pentadecylph enoxy)butylami do]benzamido}-5-pyrazolon-4-yl-ethyl carbonate
1-(2',4',6'-Trichlorophenyl)-3-{2"-chloro-5"-[γ-(2'", 4'"-di-t-pentylphenoxy)propylsulfamoyl]anilino}-5-pyrazolon- 4-yl-benzyl carbonate
In addition, other color couplers as described in British Pat. No. 1,142,553 and U.S. Pat. Nos. 3,337,344 and 3,582,322 can also be used.
Examples of four-equivalent couplers which form yellow dyes (yellow couplers), such as benzoylacetanilide or pivaloylacetanilide couplers, are described in British Pat. No. 1,113,038 and U.S. Pat. Nos. 3,337,344 and 3,582,322, and in addition, the following couplers can also be used as the yellow coupler:
α-{3-[α-m-Pentadecylphenoxy)butyramido]benzoyl}-2-chlo roacetani lide
α-{3-[α-2,4-Di-t-amylphenoxy)butyramido]benzoyl}-2-met hoxyaceta nilide
α-{3-[α-2,4-Di-t-amylphenoxy)acetamido]benzoyl}-2-chlo roacetani lide
2-Chloro-3'-[4-(2,4-di-t-amylphenoxy)butyramido]benzoyla cetanilide
α-{3-[α-(2,4-Di-t-amylphenoxy)acetamido]benxoyl}benzoy lacetanil ide
α-Pivalyl-2,5-dichloro-4-[N'-(n-octadecyl)-N'-methylsul famyl]acetanil ide
The above described compounds are examples of four-equivalent type yellow couplers which can be incorporated in photographic materials which can be treated according to this invention, and it is a matter of course that this invention is not limited to only the above-described couplers. These couplers often do not sufficiently color in a bleaching-fixation solution since a relatively stable leuco type structure occurs therebetween when a dye is formed by coupling, being different from other two-equivalent couplers. According to the steps of the method of this invention, however, even such couplers can fully be used for coloration, and in addition, the difficult problem of discharge of harmful substances is extremely improved.
It is a matter of course that photographic materials containing conventional two-equivalent couplers can be treated according to the method of this invention. Examples of such couplers are those as described in U.S. Pat. No. 3,582,322 and as described below. ##SPC1## ##SPC2## ##SPC3## ##SPC4## ##SPC5## ##SPC6## ##SPC7## ##SPC8## ##SPC9## ##SPC10## ##SPC11## ##SPC12## ##SPC13##
Other examples of yellow couplers are given below. (X represents a group to be removed by coupling.) ##SPC14## ##SPC15##
Other groups, X, to be removed by coupling are given below. ##SPC16## ##SPC17## ##SPC18## ##SPC19## ##SPC20##
These couplers can be synthesized by conventional methods as described, for example, In U.S. Pat. Nos. 3,277,155 and 3,408,194; German Pat. (OLS) No. 2,057,941; U.S. Pat. Nos. 2,350,138, 2,359,332, 2,407,210, 2,875,057, 3,265,506, 3,341,331, 3,409,439, 3,551,155, 3,551,156, and 3,649,279; British Pat. No. 1,261,156 and U.S. Pat. No. 1,296,411.
Suitable examples of magenta dye forming couplers are disclosed in the hereinbefore described U.S. Patents.
Examples of cyan dye forming couplers are disclosed in the hereinbefore cited U.S. Patents and include the following specific examples.
5-(p-Amylphenoxybenzenesulfoamido)-1-naphthol
5-(N-Benzyl-N-naphthalenesulfoamino)-1-naphthol
5-(N-Benzyl-N-n-valerylamino)-1-naphthol
5-Caproylamino-1 -naphthol
2-Chloro-5-(p-nitrobenzoyl-β-o-hydroxyethylamino)-1-nap hthol
2-Chloro-5-palmytylamino-1-naphthol
2,2'-Dihydroxy-5,5'-dibromostylbene
5-Diphenylethersulfoamido-1-naphthol
1-Hydroxy-2-(N-sec-amylphenyl)naphthamide
5-Phenoxyacetamino-1-naphthol
Monochloro-5-(N-γ-phenylpropyl-N-p-sec-amylbenzoylamino )-1-naphthol
2-Acetylamino-5-methylphenol
2-Benzoylamino-3,5-dimethylphenol
1-Hydroxy-2-[α-(2,4-di-t-amylphenoxy-n-butyl]naphthamid e
2-(4"-t-Amyl-3'-phenoxybenzoylamino)phenol
In addition, the compounds as described in U.S. Pat. No. 3,582,322 can also be utilized.
Silver halide emulsions thus prepared are applied and dried on a support such as glass, baryta paper, resin coated paper, cellulose acetate film or polyethylene terephthalate film using a dip method, an air-knife method, a bead method, an extrusion doctor method or a both surfaces coating method.
When the thus coated silver halide photographic materials are color photographic materials, the emulsion layer preferably comprises the three layers of a blue-sensitive emulsion layer, a green-sensitive emulsion layer and a red-sensitive emulsion layer, and as the case may be, at least one of these layers can comprise a number of layer. For example, the green-sensitive emulsion layer can comprise two layers, e.g., a highly sensitive layer and low sensitive layer. It is a matter of course that conventional auxiliary layers which are generally well known in this field such as a protective layer, an intermediate layer, a filter layer, an anti-halation layer and a backing layer can optionally be added.
The method of this invention can be applied to the processing of any and all conventional silver halide photographic materials where removal of silver is necessary, such as color negative films, color papers, color positive films, color reversal films for slides, color reversal films for television use and black-white reversal films. Suitable temperatures at which the bleaching method of this invention can be employed in the processing of silver halide photographic materials can range from about 10° to 60°C, preferably 20° to 50°C, with a bleaching processing time of about 30 seconds to 20 minutes, preferably 1 minute to 10 minutes.
According to the method of this invention, the toxicity of the bleaching agent used is low and the bleaching rate thereof is relatively high, and therefore, it is possible to carry out the bleaching step in a more stable manner as compared with other conventional bleaching agents. Accordingly, the time necessary for photographic processing is reduced and there is no danger of environmental pollution resulting from the discharged solution. It is a matter of course that color images finally obtained by the present method are free from any color fog and stain.
Another advantage attainable by the present method is that recovery and use of the fatigued bleaching solution are simplified. This is because bleaching agents of the kinds of the present invention can be recovered simply by blowing air or oxygen thereinto when fatigued, and therefore, recovery of silver is also easy. In view of the fact that such an advantage cannot be attained when conventional bleaching-fixation solutions are used, this advantage is considered an important additional merit of this invention.
When the bleaching solution of this invention is used, the bleaching ability thereof does not decrease even if the content of the silver halide or the silver iodide of the photographic material treated is increased. On the contrary, when a conventional non-toxic photographic bleaching agent such as a Fe(III)-aminopolycarboxylic acid complex is used, the bleaching ability thereof decreases if the content of silver halide or silver iodide is increased. In such case, although the content of silver halide or silver iodide is not critical, the standard content thereof is in general about 40 mg/100 cm 2 of silver halide and about 3 wt% of silver iodide. According to this standard, the method of this invention is suitable for treatment of photographic materials containing 40 mg/100 cm 2 or more of silver halide or 3 wt% or more of silver iodide.
The invention is further explained in greater detail by reference to the following examples. Unless otherwise indicated, all parts, percents, ratios and the like are by weight.
EXAMPLE 1
1-Hydroxy-4-chloro-2-m-dodecylnaphthamide as a cyan coupler was emulsified and mixed in a red-sensitive silver bromoiodide emulsion (AgI 7 mole%), and analogously, 1-(2',4',6'-trichlorophenyl)-3-[3"-(2"',4"'-di-t-amylphenoxy acetamido)benz amido]-5-pyrazolone as a magenta coupler in a green-sensitive silver bromoiodide emulsion (AgI 6 mole%) and α-pyvalyl-α-[4-(4-benzyloxysulfonyl)phenoxy]-2-chloro-5-[. gamm a.-(2,4-di-t-amylphenoxy)-butylamido]acetanilide as a yellow coupler in a blue-sensitive silver bromoiodide (AgI 6 mole%), and these were applied on a triacetate film base to form a color negative photographic material, which was used in the following experiment.
In the emulsification of each coupler dibutyl phthalate and tricresyl phosphate were used as coupler solvents, sorbitan monolaurate and dodecylbenzene sodium sulfonate were used as emulsifiers, and in addition, 1-(p-nonylphenoxy-trioxyethylene)-butane-4-sodium sulfonate and sucrose laurate were added as coating aids. After the film was exposed, the following Processing (I) was carried out.
Processing (I) ______________________________________ Color Development 24°C 12 min. Stopping Solution Bath " 4 min. Hardening Bath " 4 min. Water Washing " 4 min. Bleaching Bath " 6 min. Water Washing " 4 min. Fixation Bath " 8 min. Water Washing " 8 min. Drying " 10 min. Color Developer Composition Benzyl Alcohol 5 ml Sodium Hydroxide 0.5 g Diethyleneglycol 3 ml Sodium Hexametaphosphate 2 g Sodium Sulfite 2 g Potassium Bromide 2 g 4-Amino-3-methyl-N-ethyl-β-hydroxy- 5 g ethylaniline-sesquisulfate-monohydrate Metaboric Acid 0.5 g Sodium Metaborate 77 g Water to make 1 liter Stopping Solution Sodium Acetate 30 g Glacial Acetic Acid 8 ml Water to make 1 liter Hardening Bath Sodium Hexametaphosphate 1 g Borax (5H 2 O) 20 g Formalin (37%) 10 ml Water to make 1 liter Bleaching Solution I Ferric Chloride (6H 2 O) 30 g Tetrasodium Ethylenediaminetetraacetate 40 g Potassium Bromide 60 g Water to make 1 liter ______________________________________
The pH was adjusted to 6.00 with acetic acid or aqueous ammonia.
Bleaching Solution II ______________________________________ Ferric Chloride (6H 2 O) 30 g Ethylenediamine-N,N,N',N'-tetramethylene 50 g Phosphonic Acid Potassium Bromide 60 g Water to make 1 liter ______________________________________
The pH value was adjusted to 6.00 with acetic acid or aqueous ammonia.
Fixation Solution ______________________________________ Sodium Thiosulfate 150 g Sodium Sulfite 15 g Borax 12 g Glacial Acetic Acid 15 ml Potassium Alum 20 g Water to make 1 liter ______________________________________
The results were as follows: With both Bleaching Solution I and Bleaching Solution II, color images free from any color fog and stain where silver was completely removed were obtained. However, after the same treatment was repeated, the color image obtained using Bleaching Solution I somewhat contained stain due to a decrease in the bleaching ability therof. On the other hand, such a drawback was not observed at all with Bleaching Solution II. In addition, ethylenediaminetetraacetic acid in Bleaching Solution I caused environmental pollution, but there was no such danger with Bleaching Solution II.
EXAMPLE 2
On a baryta paper were applied a silver bromide emulsion containing a yellow coupler emulsified dispersion, a silver bromochloride emulsion (silver chloride 70 mole %) containing a magenta coupler emulsified dispersion, a silver bromochloride emulsion (silver chloride 70 mole %) containing a cyan coupler emulsified dispersion, and a gelatin layer containing an ultraviolet absorbing agent, to prepare a color paper. Each coupler emulsion used in the preparation of this color paper was prepared as follows: Each coupler was dissolved in a mixture of dibutyl phthalate and tricresyl phosphate, and the resulting solution was dispersed in a gelatin solution in the form of an o/w dispersion using sorbitan monolaurate, Turkey red oil and dodecylbenzene sodium sulfonate as dispersing and emulsifying agents. As the couplers, 1-(2',4',6'-trichlorophenyl)-3-[3"-(2"',4"'-di-t-amylphenoxy acetamido)benz amido]-5-pyrazolone, 1-(hydroxy)-4-chloro-2-n-dodecylnaphthamide and α-(2-methylbenzoyl)-α-chloroaceto-(2'-chloro-5'-dodecoxyca rbon yl)anilide were used. As the ultraviolet absorbing agent the compound described in U.S. Pat. No. 3,512,984 was used. In the emulsions was used 2,4-dichloro-6-hydroxy-1,3,5-triazine sodium salt as a hardener. The thus prepared color paper sample was exposed using a color printer, and then the following color development processing was carried out.
Processing (II) ______________________________________ Processing Steps Temperature Time ______________________________________ Color Development 30°C 6 min. Stopping " 2 min. Water Washing " 2 min. Bleaching " 2 min. Water Washing " 2 min. Fixation " 2 min. Water Washing " 2 min. Stabilization Bath " 2 min. Drying " 2 min. ______________________________________
The treating solutions used had the following compositions:
COLOR DEVELOPER COMPOSITION
Benzyl Alcohol 12 ml Diethyleneglycol 3.5 g Sodium Hydroxide 20 g Sodium Sulfite 20 g Potassium Bromide 0.4 g Sodium Chloride 1.0 g Borax 4.0 g Hydroxylamine Sulfate 20 g Ethylenediaminetetraacetic Acid 20 g 4-Amino-3-methyl-N-ethyl-N-(β-sulfonamido- 50 g ethyl)aniline-sesquisulfate-monohydrate Water to make 1 liter Stopping Solution Sodium Thiosulfate 10 g Ammonium Thiosulfate (70%) 30 cc Sodium Acetate 5 g Acetic Acid 30 cc Potassium Alum 15 g Water to make 1 liter Bleaching Solution Ferric Chloride (6H 2 O) 30 g 1-Hydroxyethylidene-1,1-diphosphonic 25 g Acid Aqueous Ammonia (28%) 30 ml Ammonium Bromide 60 g Water to make 1 liter
The pH was adjusted to 6.2 with acetic acid or aqueous ammonia.
______________________________________ Fixation Solution Sodium Thiosulfate 150 g Sodium Sulfite 15 g Borax 12 g Glacial Acetic Acid 15 ml Potassium Alum 20 g Water to make 1 liter Stabilization Solution Boric Acid 5 g Sodium Citrate 5 g Sodium Metaborate 3 g Potassium Alum 15 g Water to make 1 liter ______________________________________
After the above described processing a color image was obtained free from any color fog and stain where silver was completely removed. With bleaching solution of this example, there is no danger of environmental pollution, and the solution can be easily recovered, when fatigued, by blowing air thereinto. Thus, the bleaching solution is stable for a long period of time.
EXAMPLE 3
1-Hydroxy-4-chloro-2-n-dodecylnaphthamide as a cyan coupler was emulsified and mixed in a red-sensitive silver bromoiodide emulsion (AgI 7 mole %), and analogously, 1-(2',4',6'-trichlorophenyl)-3-[3",4"-di-t-amylphenoxyacetam ido)-benzamido ]-5-pyrazolone as a magenta coupler in a green-sensitive silver bromoiodide (AgI 6 mole %), and α-[2-methylbenzoyl]-aceto-(2'-chloro-5'-dodecoxycarbonyl)-a nilide as a yellow coupler in a blue-sensitive silver bromoiodide emulsion (AgI 6 mole %), and these were applied on a polyethylene terephthalate film to prepare a color reversal photographic material, which was then exposed using a sensitometer and processed according to the following Processing (III).
Processing (III) ______________________________________ Processing Steps Temperature Time ______________________________________ Pre-hardening 37°C 2 min. and 30 sec. Neutralization " 30 sec. First Development " 3 min. First Stopping " 30 sec. Water Washing " 1 min. Color Development " 3 min. and 30 sec. Second Stopping " 30 sec. Water Washing " 1 min. Bleaching " 3 min. Fixation " 1 min. Water Washing " 1 min. Each processing solution has the following composition: Pre-hardening Solution Formalin (37% aqueous solution) 20 cc Pyruvic Aldehyde (40%) 20 cc Sulfuric Acid 2 cc Sodium Sulfate 100 g Potassium Bromide 2 g Borax 5 g Water to make 1 liter Neutralization Solution Potassium Bromide 20 g Glacial Acetic Acid 10 cc Sodium Sulfate 50 g Sodium Hydroxide 6 g Glycine 10 g Water to make 1 liter First Developer Sodium Hexametaphosphate 1.0 g 1-Phenyl-3-pyrazolidone 0.3 g Sodium Sulfite 50.0 g Hydroquinone 6.0 g Sodium Carbonate (H 2 O) 35.0 g Potassium Bromide 2.0 g Potassium Thiocyanate 1.0 g Potassium Iodide (0.1% aqueous solution) 10 cc Water to make 1 liter First Stopping Solution and Second Stopping Solution Acetic Acid 25 cc Hydroxylamine Sulfate 10 g Sodium Acetate 3 g Water to make 1 liter Color Developer Sodium Hexametaphosphate 1.0 g Benzyl Alcohol 6.0 cc Sodium Sulfite 5.0 g Sodium Tertiary Phosphate 40.0 g Potassium Bromide 0.2 g Potassium Iodide (0.1% aqueous solution) 10.0 g Sodium Hydroxide 6.5 g 4-Amino-3-methyl-N-ethyl-N-methane- 10.0 g sulfonamidoethylaniline sulfate Ethylenediamine 8.0 cc Water to make 1 liter Bleaching Solution I Potassium Ferricyanide 100 g Potassium Bromide 30.0 g Water to make 1 liter Bleaching Solution II Ferric Chloride (6H 2 O) 54 g Nitrilo-N,N,N-trimethylene Phosphonic 70 g Acid Aqueous Ammonia 30 ml Ammonium Bromide 100 g Water to make 1 liter ______________________________________
The pH was adjusted to 5.8 with acetic acid or aqueous ammonia.
Fixation Solution ______________________________________ Sodium Thiosulfate 150 g Sodium Sulfite 10 g Water to make 1 liter ______________________________________
After the above processing color images were obtained free from any color fog and stain where silver is completely removed, with both Bleaching Solution I and Bleaching Solution II. When these bleaching solutions were fatigued, however, Bleaching Solution II was easily regenerated simply by blowing air thereinto and the regenerated solution could be used analogously to a fresh solution, but Bleaching Solution I cannot be regenerated by such simple treatment. In addition, the potassium ferricyanide used in the preparation of Bleaching Solution I gives rise to extreme environmental pollution if the solution thereof is discharged, but there is no such danger with Bleaching Solution II.
EXAMPLE 4
The following bleaching solution was used and otherwise the same process as in Example 2 was carried out.
Bleaching Solution Composition ______________________________________ Cobalt Acetate 24 g Ethylenediamine-N,N,N',N'-tetramethylene 40 g Phosphonic Acid Aqueous Ammonia 30 ml Ammonium Bromide 60 g Water to make 1 liter ______________________________________
The pH was adjusted to 6.2 with acetic acid or aqueous ammonia.
Analogously to Example 2, an excellent color image free from color fog and stain was obtained where the silver was completely removed.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.
1. Field of the Invention
This invention relates to a method for processing photographic materials, and more precisely, to a method for bleaching of a developed silver halide photographic emulsion layer.
2. Description of the Prior Art
In the processing of some kinds of silver halide photographic materials a step for removal of developed silver from the silver halide emulsion layer (the so-called bleaching step) is included. For example, in the processing of color photographic materials such as color negative films, color reversal films and color papers, a step for the removal of silver images formed in color development is carried out in order to retain only color images formed in the color development; and analogously, in the processing of black-white reversal photographic materials a step for the removal of silver images formed in an initial exposure and development is carried out for the purpose of formation of positive images.
Ferricyanides and iron-aminopolycarboxylic acid complexes, for example, are known as bleaching agents used in these steps. These conventional bleaching agents, however, are not completely satisfactory with respect to both non-toxicity and bleaching ability, and therefore, recently, discovery of other practical photographic bleaching agents as well as photographic bleaching methods have been desired.
SUMMARY OF THE INVENTION
An object of this invention is to provide a photographic bleaching method where a less toxic bleaching agent of a high bleaching rate is used.
Another object of this invention is to provide a method of formation of color photographic images at a much reduced bleaching time.
Still another object of this invention is to provide a method for processing color photographic materials which does not give rise to pollution problems.
These objects of this invention are achieved by the use of a bleaching solution containing a polyvalent cation-organic phosphonic acid complex as the bleaching agent. More precisely, the method of this invention comprises processing an exposed and developed silver halide emulsion layer with a bleaching solution containing a polyvalent cation-organic phosphonic acid complex as the bleaching agent.
DETAILED DESCRIPTION OF THE INVENTION
As described above, a method for processing photographic materials where a polyvalent cation-aminopolycarboxylic acid complex is used as a bleaching component is already known. The method of this invention is different from this conventional method in the use of an organic phosphonic acid in place of the aminopolycarboxylic acid, which is an important factor. Accordingly, the polyvalent cations in the present invention can be interpreted as having the same meanings as those of known polyvalent cations. Various kinds of polyvalent cations which can form complexes are known in the chemical field, and one skilled in the art can easily select these cations. Of the polyvalent cations Fe(III), Co, Ni and Cu(II) are particularly useful in the method of this invention.
On the other hand, organic phosphonic acids are also well known, and aminopolymethylene phosphonic acids (or water-soluble salts thereof) are especially advantageous. Aminopolymethylene phosphonic acids can be represented by the following general formula (I):
where M represents a hydrogen atom or a cation which imparts water-solubility (e.g., an alkali metal such as sodium or potassium; ammonium, pyridinium, triethanolammonium or triethylammonium ion); R 1 represents an alkyl group having 1 to 4 carbon atoms (e.g., a methyl, ethyl, propyl, isopropyl or butyl group), an aryl group (e.g., a phenyl, o-tolyl, m-tolyl, p-tolyl or p-carboxyphenyl group or a water-soluble salt of a p-carboxyphenyl group such as the sodium or potassium salt), an aralkyl group (e.g., benzyl, β-phenethyl or o-acetamidobenzyl group, especially an aralkyl group having 7 to 9 carbon atoms), an alicyclic group (e.g., a cyclohexyl or cyclopentyl group), or a heterocyclic group (e.g., a pyrrolidylmethyl, pyrrolidylbutyl, benzothiazoylmethyl or tetrahydroquinolylmethyl group), and R 1 (especially when representing an alkyl group) can be substituted with a hydroxyl group, an alkoxy group (e.g., a methoxy or ethoxy group), a halogen atom (e.g., a chlorine atom), --PO 3 M 2 , --CH 2 PO 3 M 2 or --N(CH 2 PO 3 M 2 ) 2 , where M has the same meaning as described above.
Representative examples of these phosphonic acids of the general formula (I) are given below.
Ethylenediamine-N,N,N',N'-tetramethylene phosphonic acid
Nitrilo-N,N,N-trimethylene phosphonic acid
1,2-Cyclohexanediamine-N,N,N',N'-tetramethylene phosphonic acid
o-Carboxyaniline-N,N-dimethylene phosphonic acid
Propylamine-N,N-dimethylene phosphonic acid
4-(N-Pyrrolidino)butylamine-N,N-bis(methylene phosphonic acid)
1,3-Diaminopropanol-N,N,N',N'-tetramethylene phosphonic acid 1,3-Propanediamine-N,N,N',N'-tetramethylene phosphonic acid
1,6-Hexanediamine-N,N,N',N'-tetramethylene phosphonic acid
o-Acetamidobenzylamine-N,N-dimethylene phosphonic acid
o-Toluidine-N,N-dimethylene phosphonic acid
2-Pyridylamine-N,N-dimethylene phosphonic acid
Other examples of organic phosphonic acids are compounds represented by the following general formula (II):
where R 2 represents a hydrogen atom, or an alkyl, aralkyl, alicyclic or heterocyclic group which is defined above, or --PO 3 M 2 ; and R 3 represents a hydrogen atom, a hydroxyl group or an alkyl group, or the above defined substituted alkyl group or --PO 3 M 2 , where M has the same meaning as described above. Representative examples of compounds of the above general formula (II) are given below.
1-Hydroxyethylidene-1,1-diphosphonic acid
Ethylidine-1,1,1-triphosphonic acid
1-Hydroxy-2-phenylethylidene-1,1-diphosphonic acid
These organic phosphonic acids are described in U.S. Pat. No. 3,617,282.
The bleaching solution used in the present invention contains as a bleaching agent the above specified polyvalent cation-organic phosphonic acid complex. The amount of this complex is generally about 20 to 200 g, preferably 50 to 150 g, per 1 liter of the bleaching solution. The lower limit of the amount of complex depends upon the bleaching ability thereof, and the upper limit thereof mainly depends upon factors such as solubility and economics. Accordingly, the upper limit of the amount of the complex can be extended further by the use of an appropriate dissolution aid, and so, the upper limit thereof is not limited to within the above mentioned scope. In the present invention it is only important that the bleaching solution contain the above described complex, and therefore, the method of addition thereof can be broadly. In general, a convenient method comprises adding a complex which was previously prepared to an aqueous solution, but apart from this, it also is possible to form the complex in an aqueous solution by adding a salt of poly-valent cation and an organic phosphonic acid to the aqueous solution. In the latter case, the amount of both compounds added are so determined that the above-described amount of complex is formed.
The bleaching solution can contain various kinds of photographic additives, and in particular, the solution preferably contains a re-halogenating agent. Examples of re-halogenating agents include an alkali metal halide (especially an alkali metal bromide) and an ammonium halide (especially ammonium bromide), and representative examples of these halides are, for example, potassium bromide, sodium bromide, sodium chloride and ammonium bromide. The content of the re-halogenating agent generally used is about 20 to 300 g, preferably 50 to 200 g, per 1 liter of the bleaching solution.
In addition, the bleaching solution of this invention can further contain other additives known in this technical field as being capable of being added to a bleaching solution or a bleaching-fixation solution. Such additives include nitrates such as sodium nitrate, sulfites such as sodium sulfite, mercapto compounds such as mercaptotriazole, pH buffers such as borates, oxalates, acetates, carbonates, phosphates, stain-inhibitors such as formamidinosulfinic acid, polyamine compounds as described, for example, in U.S. Pat. No. 3,578,454, alkylamine compounds as described, for example, in U.S. Pat. No. 3,578,453, polyethyleneoxides as described, for example, in German Pat. No. 966,410, and nitrogen containing heterocyclic compounds as described, for example, in German Pat. No. 1,290,812.
A suitable pH for the bleaching solution of this invention is a pH of about 3 to 8, preferably 5 to 7.
The method of this invention comprises the individual steps of development, bleaching and fixation. The development is generally color development, but development also means black-white development or black-white development and color development. the above-described three steps need not be necessarily carried out without interruption, and other additional steps can be carried out before and after each of these steps. Such additional steps include subjecting the photographic material to a fixation bath, an image stabilization bath, a hardening bath, a neutralization bath, a water-washing (including rinsing), etc., and, as the case may be, the bleaching and fixation step can further be included.
The color developer used in the present invention is an alkaline aqueous solution of a known aromatic primary amine color developing agent, and preferably contains 1 g/liter or more, or as the case may be, less than 1 g/liter, of benzyl alcohol. Representative examples of color developing agents are phenylenediamine derivatives such as N,N-diethyl-p-phenylenediamine sulfate, 4-amino-N-ethyl-N-β-hydroxyethylaniline sulfate, 3-methyl-4-amino-N-ethyl-β-methanesulfoamidoethylaniline-se squisulfat emonohydrate, 3-methyl-4-amino-N-ethyl-N-β-hydroxyethylaniline sulfate, 3-methyl-4-amino-N,N-diethylaniline chloride, etc. In addition, the color developer can contain known developer additives such as alkali metal sulfites, carbonates, bisulfites, bromides, iodides as well as anti-fogging agents, development accelerating agents and solvents such as diethylene glycol.
When color photographic material which do not contain a color coupler are developed, the color developer contains a color coupler (for example, as described in U.S. Pat. Nos. 2,252,718; 2,592,243 and 2,590,970).
On the other hand, when the method of this invention is applied to black-white development, an alkaline aqueous solution is used as a developer, containing developing agents such as the dihydroxybenzenes (e.g., hydroquinone, chlorohydroquinone, bromohydroquinone, isopropylhydroquinone, toluhydroquinone, methylhydroquinone, 2,3-dichloro-hydroquinone, 2,5-dimethyl-hydroquinone), the 3-pyrazolidones (e.g., 1-phenyl-3-pyrazolidone, 1-phenyl-4,4-dimethyl-3-pyrazolidone, 1-phenyl-4-ethyl-3-pyrazolidone, 1-phenyl-5-methyl-3-pyrazolidone), the aminophenols (e.g., o-aminophenol, p-aminophenol, N-methyl-o-aminophenol, N-methyl-p-aminophenol, 2,4-diaminophenol), pyrogallol, ascorbic acid, the 1-aryl-aminopyrazolines (e.g., 1-(p-hydroxyphenyl)-3-aminopyrazoline, 1-(p-methylaminophenyl)-3-aminopyrazoline, 1-(p-aminophenyl)-3-aminopyrazoline, 1-(p-amino-m-methylphenyl)-3-aminopyrazoline) or a mixture thereof. The pH of each of these black-white developers and color developers is about 9 to 13, preferably 10 to 12.5.
In the fixation step carried out after the bleaching step, each and every conventional fixing solution can be used. A suitable description thereof appears in U.S. Pat. No. 3,582,322. More precisely, about 50 to 200 g/liter or so of ammonium, sodium or potassium thiosulfate can be used as a fixing agent, and additionally, a stabilizer such as sulfite or metabisulfite, a hardening agent such as potassium alum, and a pH buffer such as acetate or borate can also be contained in the fixing solution. The fixing solution has a pH value of about 3 to 10.
Photographic materials to which the method of this invention can be applied contain at least one silver halide emulsion layer. The silver halide emulsion is prepared by dispersing a silver halide such as silver chloride, silver iodide, silver bromide, silver bromochloride, silver bromoiodide, or silver bromoiodochloride, in a hydrophilic colloid (binder).
Representative examples of hydrophilic colloids are, for example, galatin, colloidal albumin, casein, cellulose derivatives such as carboxymethyl cellulose and hydroxyethyl cellulose, saccharide derivatives such as agar, sodium alginate and starch derivatives, and synthetic hydrophilic colloids such as polyvinyl alcohol, poly-N-vinyl pyrrolidone, polyacrylic acid copolymers, polyacrylamide and derivatives thereof. If desired, a compatible mixture of two or more of these colloids can be used. Of these colloids the most common one is gelatin, and a part or all of the gelatin can be replaced by synthetic high molecular weight substances. In addition, the gelatin can also be substituted by the so-called gelatin derivatives (that is, those prepared by treating the functional groups contained in the molecule such as amino groups, imino groups, hydroxy groups or carboxyl groups, with an agent having one group capable of reacting with these functional groups) or by gelatin graft-polymers grafted with molecular chains of other high molecular weight substances. Representative examples of agents for preparing gelatin derivatives are, for example, the isocyanates, acid chlorides and acid anhydrides as described in U.S. Pat. No. 2,614,928; the acid anhydrides described in U.S. Pat. No. 3,118,766; the bromoacetic acids described in Japanese Pat. Publication No. 5514/64; the phenylglycidylethers described in Japanese Pat. Publication No. 26845/67; the vinylsulfone compounds described in U.S. Pat. No. 3,132,945; the N-allylvinyl-sulfonamides described in British Pat. No. 861,414; the maleinimide compounds described in U.S. Pat. No. 3,186,846; the acrylonitriles described in U.S. Pat. No. 2,594,293; the polyalkyleneoxides described in U.S. Pat. No. 3,312,553; the epoxy compounds described in Japanese Pat. Publication No. 26845/67; the acid esters described in U.S. Pat. No. 2,763,639; and the alkanesultones described in British Pat. No. 1,033,189. Regarding the high molecular weight substances (i.e., the branch component) which can be grafted on gelatin, a number of substances are disclosed, for example, in U.S. Pat. No. 2,763,625, No. 2,831,767 and No. 2,956,884, and Polymer Letters 5, 594 (1967), Phot. Sci. Eng., 9, 148 (1965), and J. of Polymer Sci. A-1, 9, 3199 (1971), and in addition, a broad range of polymers or copolymers of the so-called vinyl monomers such as acrylic acid and methacrylic acid or esters, amides and nitriles thereof as well as styrene can also be used as such a substance. In particular, hydrophilic vinyl polymers which are compatible with gelatin to some degree, such as the polymers or copolymers of acrylic acid, acrylamide, methacrylamide, hydroxyalkyl acrylate or hydroxyalkyl methacrylate, are especially preferred.
Silver halide emulsions can be prepared using conventional techniques which are generally well known in this technical field (e.g., the single-jet process, the double-jet process, the control-jet process) where a water-soluble silver salt (e.g., silver nitrate) and a water-soluble halide are admixed in the presence of water and the hydrophilic colloid and the mixture is subjected to physical ripening and chemical ripening such as gold sensitization and/or sulfur sensitization. To the silver halide emulsion, spectral sensitizer (e.g. cyanine dyes, merocyanine dyes or mixtures thereof, for example, as disclosed in U.S. Pat. Nos. 2,493,748; 2,519,001; 2,977,229; 3,480,434; 3,672,897; 3,703,377; 2,688,545; 2,912,329; 3,397,060; 3,615,635; 3,628,964; 3,522,052; 3,527,641; 3,615,613; 3,515,632; 3,617,295; 3,635,721; 3,694,217; etc.), stabilizers (e.g., 4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene), sensitizers (e.g., the compounds described in U.S. Pat. No. 3,619,198), anti-fogging agents (e.g., benzotriazole, 5-nitrobenzimidazole, polyethyleneoxide), hardening agents (e.g., aldehyde compounds such as formaldehyde and glyoxal, nonaldehyde compounds such as mucochloric acid and 2-hydroxy-4,6-dichloro-s-triazine, for example, as described in U.S. Pat. Nos. 3,288,775; 2,732,303; 3,635,718; 3,232,763; 2,732,316; 2,586,168; 3,103,437; 3,017,280; 2,983,611; 2,725,294; 2,725,295; 3,100,704; 3,091,537; 3,321,313; 3,543,292; etc.) and coating auxiliaries (e.g., saponin, sodium lauryl sulfate, dodecylphenolpolyethyleneoxide ether, hexadecyltrimethylammonium bromide) can be added during the preparation thereof or immediately before the application thereof. The silver halides in the emulsion thus obtained preferably have an average particle size of about 0.2 to 1.5 μ.
When the method of this invention is applied to a system where a color coupler is contained in a photographic material (as disclosed in U.S. Pat. Nos. 2,376,679, 2,322,027 and 2,801,171), at least one silver halide emulsion layer can contain a color coupler (i.e., a compound forming a dye after reaction with an oxidation product of a color developing agent). In general, each of a cyan, magenta and yellow color coupler is used in color photography. Suitable examples of color couplers are described as follows: cyan couplers;
U.S. Pat. Nos. 2,474,293; 2,698,794; 3,034,892; 3,214,437; 3,253,924; 3,311,476; 3,458,315; 3,582,322; 3,591,383; etc.
magenta couplers;
U.S. Pat. Nos. 2,600,788; 2,983,608; 3,006,759; 3,062,653; 3,214,437; 3,253,924; 3,311,476; 3,337,344; 3,419,391; 3,419,808; 3,476,560; 3,582,322; etc.
yellow couplers;
U.S. Pat. Nos. 3,277,157; 3,415,652; 3,447,928; 3,311,476; 3,408,194; 2,875,057; 3,265,506; 3,409,439; 3,551,157; 3,551,156; 3,582,322; etc.
More precisely, a color coupler which has a naphthol or phenol skeleton and can form an indoaniline dye by coupling is used as a cyan coupler; a color coupler which has active methylene groups and a 5-pyrazolone ring structure sleketon is used as a magenta coupler; and a color coupler of a benzoylacetanilide, pivalylacetanilide or acrylacetanilide structure with or without a substituent in the coupling position, is used as a yellow coupler. This is because the bleaching solution of this invention has a sufficient oxidizability to increase the color density.
Representative of pyrazolone color couplers are those represented by the general formula (III) ##EQU1## wherein, R 4 represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, and R 5 represents an alkyl group, a carbamyl group, an amino group or an amido group. Examples of compounds represented by the above formula are as follows:
1-p-sec-Amylphenyl-3-n-amyl-5-pyrazolone
2-Cyanoacetyl-5-(p-sec-amylbenzoylamino)coumarone
2-Cyanoacetylcoumaron-5-(N-n-amyl-p-t-amylsulfoanilide)
2-Cyanoacetylcoumaron-5-sulfon-N-n-butylanilide
1-p-Laurylphenyl-3-methyl-5-pyrazolone
1-β-Naphthyl-3-amyl-5-pyrazolone
1-p-Nitrophenyl-3-n-amyl-5-pyrazolone
1-Phenyl-3-acetylamino-5-pyrazolone
1-Phenyl-3-n-valerylamino-5-pyrazolone
1-Phenyl-3-chloroacetylamino-5-pyrazolone
1-Phenyl-3-(m-aminobenzoyl)amino-5-pyrazolone
1-p-Phenoxyphenyl-3-(p-t-amyloxybenzoyl)amino-5-pyrazolo ne
1-(2',4',6'-Trichlorophenyl)-3-benzamido-5-pyrazolone
1-(2',4'-Dichlorophenyl)-3-[3"-(2'",4'"-di-t-amylphenoxy acetamido)benzamido ]-5-pyrazolone
1-(2,4-Dimethyl-6-chlorophenyl)-3-[3'-(2'",4'"-di-t-amyl phenoxyacetamido)be nzamido]-5-pyrazolone
In addition, the following couplers can also be used:
1-(2',4',6'-Trichlorophenyl)-3-(2"-chloro-5"-tetradecane amidoanilino)-5-pyr azolone
1-(2',4',6'-Trichlorophenyl)-3-{2"'-chloro-5"-[N-3'"-(2' ",5'"-di-t-pentylph enoxy)propyl]sulfamoylanilino}-5-pyrazolone
1-(2',4',6'-Trichlorophenyl)-3-(2"-chloro-4"-tetradecylo xy-carbonylanilino) -5-pyrazolone
1-(2',6'-Dichloro-4'-tetradecyloxycarbonylphenyl)-3-(2,4 -dichloroanilino)-5 -pyrazolone
1-(2',4',6'-Trichlorophenyl)-3-{2"-chloro-5"-[2'"-(3'"-t -butyl-4'"-hydroxyp henoxy)tetradecaneamido]anilino}-5-pyrazolone
1-(2',4',6'-Trichlorophenyl)-3-(2"-chloro-5"-tetradecane amidoanilino)-5-pyr azolone
1-(2',4',6'-Trichlorophenyl)-3-{3"-[α-2'",4'"-di-t-pent ylphenoxy)acet amido]benzamido}-5-pyrazolon-4-yl-benzyl carbonate
1-(2',4',6'-Trichlorophenyl)-3-{3"-[α-(3'"-pentadecylph enoxy)butylami do]benzamido}-5-pyrazolon-4-yl-ethyl carbonate
1-(2',4',6'-Trichlorophenyl)-3-{2"-chloro-5"-[γ-(2'", 4'"-di-t-pentylphenoxy)propylsulfamoyl]anilino}-5-pyrazolon- 4-yl-benzyl carbonate
In addition, other color couplers as described in British Pat. No. 1,142,553 and U.S. Pat. Nos. 3,337,344 and 3,582,322 can also be used.
Examples of four-equivalent couplers which form yellow dyes (yellow couplers), such as benzoylacetanilide or pivaloylacetanilide couplers, are described in British Pat. No. 1,113,038 and U.S. Pat. Nos. 3,337,344 and 3,582,322, and in addition, the following couplers can also be used as the yellow coupler:
α-{3-[α-m-Pentadecylphenoxy)butyramido]benzoyl}-2-chlo roacetani lide
α-{3-[α-2,4-Di-t-amylphenoxy)butyramido]benzoyl}-2-met hoxyaceta nilide
α-{3-[α-2,4-Di-t-amylphenoxy)acetamido]benzoyl}-2-chlo roacetani lide
2-Chloro-3'-[4-(2,4-di-t-amylphenoxy)butyramido]benzoyla cetanilide
α-{3-[α-(2,4-Di-t-amylphenoxy)acetamido]benxoyl}benzoy lacetanil ide
α-Pivalyl-2,5-dichloro-4-[N'-(n-octadecyl)-N'-methylsul famyl]acetanil ide
The above described compounds are examples of four-equivalent type yellow couplers which can be incorporated in photographic materials which can be treated according to this invention, and it is a matter of course that this invention is not limited to only the above-described couplers. These couplers often do not sufficiently color in a bleaching-fixation solution since a relatively stable leuco type structure occurs therebetween when a dye is formed by coupling, being different from other two-equivalent couplers. According to the steps of the method of this invention, however, even such couplers can fully be used for coloration, and in addition, the difficult problem of discharge of harmful substances is extremely improved.
It is a matter of course that photographic materials containing conventional two-equivalent couplers can be treated according to the method of this invention. Examples of such couplers are those as described in U.S. Pat. No. 3,582,322 and as described below. ##SPC1## ##SPC2## ##SPC3## ##SPC4## ##SPC5## ##SPC6## ##SPC7## ##SPC8## ##SPC9## ##SPC10## ##SPC11## ##SPC12## ##SPC13##
Other examples of yellow couplers are given below. (X represents a group to be removed by coupling.) ##SPC14## ##SPC15##
Other groups, X, to be removed by coupling are given below. ##SPC16## ##SPC17## ##SPC18## ##SPC19## ##SPC20##
These couplers can be synthesized by conventional methods as described, for example, In U.S. Pat. Nos. 3,277,155 and 3,408,194; German Pat. (OLS) No. 2,057,941; U.S. Pat. Nos. 2,350,138, 2,359,332, 2,407,210, 2,875,057, 3,265,506, 3,341,331, 3,409,439, 3,551,155, 3,551,156, and 3,649,279; British Pat. No. 1,261,156 and U.S. Pat. No. 1,296,411.
Suitable examples of magenta dye forming couplers are disclosed in the hereinbefore described U.S. Patents.
Examples of cyan dye forming couplers are disclosed in the hereinbefore cited U.S. Patents and include the following specific examples.
5-(p-Amylphenoxybenzenesulfoamido)-1-naphthol
5-(N-Benzyl-N-naphthalenesulfoamino)-1-naphthol
5-(N-Benzyl-N-n-valerylamino)-1-naphthol
5-Caproylamino-1 -naphthol
2-Chloro-5-(p-nitrobenzoyl-β-o-hydroxyethylamino)-1-nap hthol
2-Chloro-5-palmytylamino-1-naphthol
2,2'-Dihydroxy-5,5'-dibromostylbene
5-Diphenylethersulfoamido-1-naphthol
1-Hydroxy-2-(N-sec-amylphenyl)naphthamide
5-Phenoxyacetamino-1-naphthol
Monochloro-5-(N-γ-phenylpropyl-N-p-sec-amylbenzoylamino )-1-naphthol
2-Acetylamino-5-methylphenol
2-Benzoylamino-3,5-dimethylphenol
1-Hydroxy-2-[α-(2,4-di-t-amylphenoxy-n-butyl]naphthamid e
2-(4"-t-Amyl-3'-phenoxybenzoylamino)phenol
In addition, the compounds as described in U.S. Pat. No. 3,582,322 can also be utilized.
Silver halide emulsions thus prepared are applied and dried on a support such as glass, baryta paper, resin coated paper, cellulose acetate film or polyethylene terephthalate film using a dip method, an air-knife method, a bead method, an extrusion doctor method or a both surfaces coating method.
When the thus coated silver halide photographic materials are color photographic materials, the emulsion layer preferably comprises the three layers of a blue-sensitive emulsion layer, a green-sensitive emulsion layer and a red-sensitive emulsion layer, and as the case may be, at least one of these layers can comprise a number of layer. For example, the green-sensitive emulsion layer can comprise two layers, e.g., a highly sensitive layer and low sensitive layer. It is a matter of course that conventional auxiliary layers which are generally well known in this field such as a protective layer, an intermediate layer, a filter layer, an anti-halation layer and a backing layer can optionally be added.
The method of this invention can be applied to the processing of any and all conventional silver halide photographic materials where removal of silver is necessary, such as color negative films, color papers, color positive films, color reversal films for slides, color reversal films for television use and black-white reversal films. Suitable temperatures at which the bleaching method of this invention can be employed in the processing of silver halide photographic materials can range from about 10° to 60°C, preferably 20° to 50°C, with a bleaching processing time of about 30 seconds to 20 minutes, preferably 1 minute to 10 minutes.
According to the method of this invention, the toxicity of the bleaching agent used is low and the bleaching rate thereof is relatively high, and therefore, it is possible to carry out the bleaching step in a more stable manner as compared with other conventional bleaching agents. Accordingly, the time necessary for photographic processing is reduced and there is no danger of environmental pollution resulting from the discharged solution. It is a matter of course that color images finally obtained by the present method are free from any color fog and stain.
Another advantage attainable by the present method is that recovery and use of the fatigued bleaching solution are simplified. This is because bleaching agents of the kinds of the present invention can be recovered simply by blowing air or oxygen thereinto when fatigued, and therefore, recovery of silver is also easy. In view of the fact that such an advantage cannot be attained when conventional bleaching-fixation solutions are used, this advantage is considered an important additional merit of this invention.
When the bleaching solution of this invention is used, the bleaching ability thereof does not decrease even if the content of the silver halide or the silver iodide of the photographic material treated is increased. On the contrary, when a conventional non-toxic photographic bleaching agent such as a Fe(III)-aminopolycarboxylic acid complex is used, the bleaching ability thereof decreases if the content of silver halide or silver iodide is increased. In such case, although the content of silver halide or silver iodide is not critical, the standard content thereof is in general about 40 mg/100 cm 2 of silver halide and about 3 wt% of silver iodide. According to this standard, the method of this invention is suitable for treatment of photographic materials containing 40 mg/100 cm 2 or more of silver halide or 3 wt% or more of silver iodide.
The invention is further explained in greater detail by reference to the following examples. Unless otherwise indicated, all parts, percents, ratios and the like are by weight.
EXAMPLE 1
1-Hydroxy-4-chloro-2-m-dodecylnaphthamide as a cyan coupler was emulsified and mixed in a red-sensitive silver bromoiodide emulsion (AgI 7 mole%), and analogously, 1-(2',4',6'-trichlorophenyl)-3-[3"-(2"',4"'-di-t-amylphenoxy acetamido)benz amido]-5-pyrazolone as a magenta coupler in a green-sensitive silver bromoiodide emulsion (AgI 6 mole%) and α-pyvalyl-α-[4-(4-benzyloxysulfonyl)phenoxy]-2-chloro-5-[. gamm a.-(2,4-di-t-amylphenoxy)-butylamido]acetanilide as a yellow coupler in a blue-sensitive silver bromoiodide (AgI 6 mole%), and these were applied on a triacetate film base to form a color negative photographic material, which was used in the following experiment.
In the emulsification of each coupler dibutyl phthalate and tricresyl phosphate were used as coupler solvents, sorbitan monolaurate and dodecylbenzene sodium sulfonate were used as emulsifiers, and in addition, 1-(p-nonylphenoxy-trioxyethylene)-butane-4-sodium sulfonate and sucrose laurate were added as coating aids. After the film was exposed, the following Processing (I) was carried out.
Processing (I) ______________________________________ Color Development 24°C 12 min. Stopping Solution Bath " 4 min. Hardening Bath " 4 min. Water Washing " 4 min. Bleaching Bath " 6 min. Water Washing " 4 min. Fixation Bath " 8 min. Water Washing " 8 min. Drying " 10 min. Color Developer Composition Benzyl Alcohol 5 ml Sodium Hydroxide 0.5 g Diethyleneglycol 3 ml Sodium Hexametaphosphate 2 g Sodium Sulfite 2 g Potassium Bromide 2 g 4-Amino-3-methyl-N-ethyl-β-hydroxy- 5 g ethylaniline-sesquisulfate-monohydrate Metaboric Acid 0.5 g Sodium Metaborate 77 g Water to make 1 liter Stopping Solution Sodium Acetate 30 g Glacial Acetic Acid 8 ml Water to make 1 liter Hardening Bath Sodium Hexametaphosphate 1 g Borax (5H 2 O) 20 g Formalin (37%) 10 ml Water to make 1 liter Bleaching Solution I Ferric Chloride (6H 2 O) 30 g Tetrasodium Ethylenediaminetetraacetate 40 g Potassium Bromide 60 g Water to make 1 liter ______________________________________
The pH was adjusted to 6.00 with acetic acid or aqueous ammonia.
Bleaching Solution II ______________________________________ Ferric Chloride (6H 2 O) 30 g Ethylenediamine-N,N,N',N'-tetramethylene 50 g Phosphonic Acid Potassium Bromide 60 g Water to make 1 liter ______________________________________
The pH value was adjusted to 6.00 with acetic acid or aqueous ammonia.
Fixation Solution ______________________________________ Sodium Thiosulfate 150 g Sodium Sulfite 15 g Borax 12 g Glacial Acetic Acid 15 ml Potassium Alum 20 g Water to make 1 liter ______________________________________
The results were as follows: With both Bleaching Solution I and Bleaching Solution II, color images free from any color fog and stain where silver was completely removed were obtained. However, after the same treatment was repeated, the color image obtained using Bleaching Solution I somewhat contained stain due to a decrease in the bleaching ability therof. On the other hand, such a drawback was not observed at all with Bleaching Solution II. In addition, ethylenediaminetetraacetic acid in Bleaching Solution I caused environmental pollution, but there was no such danger with Bleaching Solution II.
EXAMPLE 2
On a baryta paper were applied a silver bromide emulsion containing a yellow coupler emulsified dispersion, a silver bromochloride emulsion (silver chloride 70 mole %) containing a magenta coupler emulsified dispersion, a silver bromochloride emulsion (silver chloride 70 mole %) containing a cyan coupler emulsified dispersion, and a gelatin layer containing an ultraviolet absorbing agent, to prepare a color paper. Each coupler emulsion used in the preparation of this color paper was prepared as follows: Each coupler was dissolved in a mixture of dibutyl phthalate and tricresyl phosphate, and the resulting solution was dispersed in a gelatin solution in the form of an o/w dispersion using sorbitan monolaurate, Turkey red oil and dodecylbenzene sodium sulfonate as dispersing and emulsifying agents. As the couplers, 1-(2',4',6'-trichlorophenyl)-3-[3"-(2"',4"'-di-t-amylphenoxy acetamido)benz amido]-5-pyrazolone, 1-(hydroxy)-4-chloro-2-n-dodecylnaphthamide and α-(2-methylbenzoyl)-α-chloroaceto-(2'-chloro-5'-dodecoxyca rbon yl)anilide were used. As the ultraviolet absorbing agent the compound described in U.S. Pat. No. 3,512,984 was used. In the emulsions was used 2,4-dichloro-6-hydroxy-1,3,5-triazine sodium salt as a hardener. The thus prepared color paper sample was exposed using a color printer, and then the following color development processing was carried out.
Processing (II) ______________________________________ Processing Steps Temperature Time ______________________________________ Color Development 30°C 6 min. Stopping " 2 min. Water Washing " 2 min. Bleaching " 2 min. Water Washing " 2 min. Fixation " 2 min. Water Washing " 2 min. Stabilization Bath " 2 min. Drying " 2 min. ______________________________________
The treating solutions used had the following compositions:
COLOR DEVELOPER COMPOSITION
Benzyl Alcohol 12 ml Diethyleneglycol 3.5 g Sodium Hydroxide 20 g Sodium Sulfite 20 g Potassium Bromide 0.4 g Sodium Chloride 1.0 g Borax 4.0 g Hydroxylamine Sulfate 20 g Ethylenediaminetetraacetic Acid 20 g 4-Amino-3-methyl-N-ethyl-N-(β-sulfonamido- 50 g ethyl)aniline-sesquisulfate-monohydrate Water to make 1 liter Stopping Solution Sodium Thiosulfate 10 g Ammonium Thiosulfate (70%) 30 cc Sodium Acetate 5 g Acetic Acid 30 cc Potassium Alum 15 g Water to make 1 liter Bleaching Solution Ferric Chloride (6H 2 O) 30 g 1-Hydroxyethylidene-1,1-diphosphonic 25 g Acid Aqueous Ammonia (28%) 30 ml Ammonium Bromide 60 g Water to make 1 liter
The pH was adjusted to 6.2 with acetic acid or aqueous ammonia.
______________________________________ Fixation Solution Sodium Thiosulfate 150 g Sodium Sulfite 15 g Borax 12 g Glacial Acetic Acid 15 ml Potassium Alum 20 g Water to make 1 liter Stabilization Solution Boric Acid 5 g Sodium Citrate 5 g Sodium Metaborate 3 g Potassium Alum 15 g Water to make 1 liter ______________________________________
After the above described processing a color image was obtained free from any color fog and stain where silver was completely removed. With bleaching solution of this example, there is no danger of environmental pollution, and the solution can be easily recovered, when fatigued, by blowing air thereinto. Thus, the bleaching solution is stable for a long period of time.
EXAMPLE 3
1-Hydroxy-4-chloro-2-n-dodecylnaphthamide as a cyan coupler was emulsified and mixed in a red-sensitive silver bromoiodide emulsion (AgI 7 mole %), and analogously, 1-(2',4',6'-trichlorophenyl)-3-[3",4"-di-t-amylphenoxyacetam ido)-benzamido ]-5-pyrazolone as a magenta coupler in a green-sensitive silver bromoiodide (AgI 6 mole %), and α-[2-methylbenzoyl]-aceto-(2'-chloro-5'-dodecoxycarbonyl)-a nilide as a yellow coupler in a blue-sensitive silver bromoiodide emulsion (AgI 6 mole %), and these were applied on a polyethylene terephthalate film to prepare a color reversal photographic material, which was then exposed using a sensitometer and processed according to the following Processing (III).
Processing (III) ______________________________________ Processing Steps Temperature Time ______________________________________ Pre-hardening 37°C 2 min. and 30 sec. Neutralization " 30 sec. First Development " 3 min. First Stopping " 30 sec. Water Washing " 1 min. Color Development " 3 min. and 30 sec. Second Stopping " 30 sec. Water Washing " 1 min. Bleaching " 3 min. Fixation " 1 min. Water Washing " 1 min. Each processing solution has the following composition: Pre-hardening Solution Formalin (37% aqueous solution) 20 cc Pyruvic Aldehyde (40%) 20 cc Sulfuric Acid 2 cc Sodium Sulfate 100 g Potassium Bromide 2 g Borax 5 g Water to make 1 liter Neutralization Solution Potassium Bromide 20 g Glacial Acetic Acid 10 cc Sodium Sulfate 50 g Sodium Hydroxide 6 g Glycine 10 g Water to make 1 liter First Developer Sodium Hexametaphosphate 1.0 g 1-Phenyl-3-pyrazolidone 0.3 g Sodium Sulfite 50.0 g Hydroquinone 6.0 g Sodium Carbonate (H 2 O) 35.0 g Potassium Bromide 2.0 g Potassium Thiocyanate 1.0 g Potassium Iodide (0.1% aqueous solution) 10 cc Water to make 1 liter First Stopping Solution and Second Stopping Solution Acetic Acid 25 cc Hydroxylamine Sulfate 10 g Sodium Acetate 3 g Water to make 1 liter Color Developer Sodium Hexametaphosphate 1.0 g Benzyl Alcohol 6.0 cc Sodium Sulfite 5.0 g Sodium Tertiary Phosphate 40.0 g Potassium Bromide 0.2 g Potassium Iodide (0.1% aqueous solution) 10.0 g Sodium Hydroxide 6.5 g 4-Amino-3-methyl-N-ethyl-N-methane- 10.0 g sulfonamidoethylaniline sulfate Ethylenediamine 8.0 cc Water to make 1 liter Bleaching Solution I Potassium Ferricyanide 100 g Potassium Bromide 30.0 g Water to make 1 liter Bleaching Solution II Ferric Chloride (6H 2 O) 54 g Nitrilo-N,N,N-trimethylene Phosphonic 70 g Acid Aqueous Ammonia 30 ml Ammonium Bromide 100 g Water to make 1 liter ______________________________________
The pH was adjusted to 5.8 with acetic acid or aqueous ammonia.
Fixation Solution ______________________________________ Sodium Thiosulfate 150 g Sodium Sulfite 10 g Water to make 1 liter ______________________________________
After the above processing color images were obtained free from any color fog and stain where silver is completely removed, with both Bleaching Solution I and Bleaching Solution II. When these bleaching solutions were fatigued, however, Bleaching Solution II was easily regenerated simply by blowing air thereinto and the regenerated solution could be used analogously to a fresh solution, but Bleaching Solution I cannot be regenerated by such simple treatment. In addition, the potassium ferricyanide used in the preparation of Bleaching Solution I gives rise to extreme environmental pollution if the solution thereof is discharged, but there is no such danger with Bleaching Solution II.
EXAMPLE 4
The following bleaching solution was used and otherwise the same process as in Example 2 was carried out.
Bleaching Solution Composition ______________________________________ Cobalt Acetate 24 g Ethylenediamine-N,N,N',N'-tetramethylene 40 g Phosphonic Acid Aqueous Ammonia 30 ml Ammonium Bromide 60 g Water to make 1 liter ______________________________________
The pH was adjusted to 6.2 with acetic acid or aqueous ammonia.
Analogously to Example 2, an excellent color image free from color fog and stain was obtained where the silver was completely removed.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.