US3907568A

US3907568A - Process for regenerating blixing solution for color photographic processing

Info

Publication number: US3907568A
Application number: US298712A
Authority: US
Inventors: Kazuo Shirasu; Sachio Matsushita; Tadao Hatano; Haruhiko Iwano
Original assignee: Fuji Photo Film Co Ltd
Current assignee: Fujifilm Holdings Corp
Priority date: 1971-10-22
Filing date: 1972-10-18
Publication date: 1975-09-23
Anticipated expiration: 1992-09-23
Also published as: JPS5633697B2; FR2156874B1; FR2156874A1; CA991468A; DE2251908A1; JPS4849437A; IT966430B; BE790374A

Abstract

A process of regenerating a blixing solution used in color photographic processings by suppressing the silver ion concentration in the solution to a low level, make up components being added to the blixing solution after processing as necessary.

Description

United States Patent [1 1 Shirasu et al.

[451 Sept. 23, 1975 PROCESS FOR REGENERATING BLIXING SOLUTION FOR COLOR PHOTOGRAPHIC PROCESSING Inventors: Kazuo Shirasu; Sachio Matsushita;

Tadao Hatano; Haruhiko lwano, all of Kanagawa, Japan Assignee: Fuji Photo Film Co., Ltd., Minamiashigara, Japan Filed: Oct. 18, 1972 Appl. No.: 298,712

Foreign Application Priority Data Oct. 22, 1971 Japan 46-83790 us. Cl 96/60 BF; 96/22; 96/50 A;

V 96/55 m. cm G03C 1/32; 603C 5/26 Field of Search 96/50 A, 60, 61 M, 60 BF, 96/61 R, 66.1. 66 R. 48 QP. 55; 210/190, 59.

[56] References Cited UNITED STATES PATENTS 3.241966 3/1966 Heilmawn et a1. 96/60 BF 3.620.725 11/1971 Kosta 96/22 3.634.088 10/1972 Cooley 96/60 BF 3.706.561 12/1972 Mowrey ct a1v 96/60 BF Primary Examinen-Norman G. Torchin Assistant E.\'aminerAlfonso T. Suro Pico Attorney, Agent, or Firm-Sughrue, Rothwell. Mion. Zinn & Macpeak 14 Claims, No Drawings PROCESS FOR REGENERATING BLIXINO SOLUTION FOR COLOR PHOTOGRAPHIC PROCESSING BACKGROUND OF THE INVENTION 1. Field of The Invention:

The present invention relates generally to processing photographic materials. in particular. blixing color photographic light-sensitive materials. More particularly. the invention relates to regenerating a used blixing solution for reuse in color photographic processing.

2. Description of The Prior Art:

The combination of bleaching and fixing in photographic processing has been known for a long time. that is. where both bleaching and fixing are conducted simultaneously in processing a silver halide photographic material.

The necessary components for a blixing solution are one or more bleaching agents which oxidize the metallic silver of a silver image and one or more fixing agents which dissolve both undeveloped silver halide and the silver halide formed by the oxidation of the developed silver by the bleaching agent. Various formulations for blixing solutions have been known in the field of photography. but a blixing solution using a combination of a ferric salt of an aminopolycarboxylic acid as the blcachingagent and a thiosulfate as the fixing agent is most used because of its stability. high reaction rate and ease of handling. However. a blixing composition comprising a thiosulfate and a ferric salt of an aminopolycarboxylic acid is comparatively expensive and further it must be discarded after use since no acceptable regeneration method therefor exists. disadvantages to the industrial utilization ofblixing solutions of this type.

Although it has been known to regenerate used bleaching solutions or fixing solutions for reusee. known regneration processes are inapplicable to the regeneration of the aforesaid blixing solution. For instance. a ferricyanide-containing bleaching solution may be regenerated by treatment with bromine as dcscribed in the specification of 15.5. Pat. No. 2.515.930; by treating with a bromine releasing reagent in an aqueous solution as described in the specification of U.S. Pat. No. 2.61 1.699 and the specification of U.S. Pat. No. 2.6] 1.700; or by treating with a water-soluble persulfate as described in the specification of U.S. Pat. No. 2.944.895. A used fixing solution can be reused by re moving all or a part ofthe silver from the fixing solution and adding components to the fixing solution necessary to provide the original formulation. Such a process is disclosed in the specifications of U.S. Pat. Nos. 1.446.405. 1.527.942. and 3.082.079.

However. it is undesirable to regenerate a blixing solution of the type indicated above with bromine or a persulfate because while such reagents accomplish the desirable oxidation of ferrous ions in solution. they at the same time oxidize thiosulfate ions into sulfate ions or other oxidation product ions. whereby the fixing faculty of the solution is degraded. Accordingly. when such a blixing solution is used in a conventional system. the blixing solution must be discarded after only one use. which results in an economic loss as well as causing water pollution problems.

To overcome these difficulties. a bleaching solution regeneration process has been proposed in Japanese patent application laid open to public inspection No.

781/71. The regeneration process is fora used blixing solution containing a ferric salt of aminopolycarboxylic acid as a bleaching agent and a thiosulfate as a fixing agent together with silver complex ions and ferrous ions in the blixing process. At least a part of the silver ions is removed from the blixing solution and oxygen is introduced into the blixing solution in an amount sufficient to convert the ferrous ions into ferric ions. whereby the oxidation potential of the blixing solution is recovered without losing the thiosulfate. and thus the blixing solution is brought into a reusable state.

According to the above process the desirable oxidation of ferrous ions into ferric ions to some extent can be conducted. thus the solution becomes reusable. the contamination problem can be solved. and further the processing cost can be reduced. However. such a conventional process is accompanied by various faults and thus is hardly an excellent process. That is to say. according to the aforesaid process at least a part of the silver ions is removed in some manner before the ferrous ions are oxidized by oxygen into ferric ions. but the removal of silver ions encounters. in general. technical and practical difficulties. For instance. in the case of removing silver ions by the addition of sodium sulfide. it is necessary to critically control the amount of sodium sulfide added to prevent the formation of sulfide stains. and further it is difficult to maintain the pH value constant. Accordingly. such a process will not be practically employed in many color laboratories.

Furthermore. in the case of recovering silver ions from the used blixing solution by electrolysis. the cost of equipment is large due to the low current efficiency. and it is also difficult to maintain the electrolysis conditions constant. Accordingly. such a process will also not be practically employed in many color laboratories.

Therefore. the only practical process of this type is the process wherein. as clearly stated in the abovemcntioncd patent application. silver ions are removed by bringing the deteriorated blixing solution into contact with metallic iron to cause a replacement reaction. However. this process is not satisfactory in every case since although silver ions may be removed by the contact of the blixing solution with metallic iron. the ferric salt is at the same time reduced into the ferrous salt. and thus a strong oxidation becomes necessary in order to oxidize all of the ferrous salt for recovering the activity of the blixing solution as a bleaching solution. Therefore. it is necessary to use a particularly effective oxygen mixing means or oxidation must be conducted for a long period of time.

A further fault in such a process is that since metallic iron is oxidized and dissolved in the solution. the concentration of iron ions varies during the repeated practice of the regeneration of the blixing solution and thus it is very troublesome to control at stable concentra tions iron ions in the blixing solution.

It is also inevitable in conventional processes that some part of the expensive blixing solution will be lost during preventing the increase in iron salt concentration since it is difficult to completely regenerate the blixing solution.

SUMMARY oF THE INVENTION One object of this invention is. therefor. to provide a process for the regeneration ofa usedblixing solution which can be practiced in an economical. simple. and stable manner without being "accompanied by the aforesaid disadvantages of the prior art. 5

Another object of this invention is to provide a color photographic processing systemin which an expensive blixing solution can be repeatedly used in a simple manner.

Yet another object of this invention is to provide a color photographic processing system which gives no or less water contamination or pollution. problems caused by the used blixing solution.

According to the present invention. there is provided a process in which a used blixing solution'can be regenerated by keeping the silver ion concentration in' the blixing solution at processing to a low level, which does not lead to difficulties such as a decrease in' bleaching rate. wherein a small amount of make up (deficient) components are added to the blixing solution to recover the original composition of the blixing solution without the necessity of removing silver ions and thus withoutthe necessity of intentionally oxidizing the ferrous ions by oxygen. I

' DETAILED EXPLANATION OF THE INVENTION The silver ion concentration in a blixing solution may be kept below a certain level by employing a fixing bath prior to the blixing process. whereby the greater part of the soluble silver salt is dissolved in the fixing bath to prevent a large accumulation of the silver salt or silver ion in the blixing bath during the subsequent blixing step. or alternatively by reducing the amount of silver salts incorporated in the photographic light-sensitive material. whereby the accumulation of an undesirable level of silver ions in the blixing bath at processing is prevented. Ordinarily, when the amount of silver used in a silver halide photographic material is less than 2 g/m, the accumulation of silver ions to an extent which has a harmful influence on blixing can be prevented without fixing. More preferably, the amount is less than L6 glm and most preferably it is in the range of l.() l.5 g/m to insure long term operation.

Ifthe accumulation of silver ions to an extent that has a bad influence on blixing can thus bc, prevented. the procedure of bringing the used blixing solution into contact with metallic iron to remove silver in the solution becomes unnecessary. Furthermore because the concentration of the ferrous ions in the blixing solution converted from the ferric ions during the oxidation of the developed silver is minor as compared with the total amount of the ferric ions. the introduction'of oxygen into the used blixing solution toregenerate the same becomes unnecessary. In the process disclosed Japanese patent application laid open to public inspection No. 781/71, ferrous ions are oxidized into ferric ions by intentionally introducing oxygen into the used blixing solution to convert the ferrous ions into ferric ions at the same time that the blixing solution is brought into contact with metallic iron to remove silver ions.

It can generally be said that acceptable results are obtained so long as the amount of silver ions present in the blix bath is maintained below about l() g/ I. more preferably below 5 g/ 1. Maximum efficiency of blixing is obtainetf'when the amount of silver is maintained below 3 g/ l.

The coated amount of silver halide for normal silver halide photographic elements is 2.0 to about l0 g/m For example: i l

Color paper 2.0 25 g/m" (.olor positive film 3.0 3.5 g/m' (for movies) ('olor negative film 4.0 It] glm Accordingly. when treating the above silverhalide elements by the method of the present invention. a fixing step must be carried out before blixing.

The blixing solution to which the .process of this invention is applied is a solution containing a fixing agent diaminotetraacetic acid. ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, ethyleneglycol bis(aminoethylether)tetraacetic acid. diaminopropanol tetraacetic' acid. N-( Z-hydroxyethyl )ethylenediamine triacetic acid, cthyliminodopropionic acid, and the like. Other bleaching agents useful in the present invention are disclosed in US. Pat. No. 3,582,322.

The ferric salt of an amino'poly carboxylic acid used in this invention may be a ferric salt wherein all of the cations are ferric ions or it may be a ferric salt where at least one carboxyl group is bonded to a cation other than an iron ion, such as ammonia or an alkali metal ion. A prefered example of such a ferric salt is sodium ferric ethylene'diamine tetraacetic acid.

In the blixing solution used in this invention. bleaching agents other than those listed may be used above. such a polyanimine cobalt complex salt such as tetramminecarbonate cobalttlll) nitrate, quinones. or a simple water-soluble iron salt, e.g., ferric chloride. Moreover, besides the aforesaid ferric salts, a nonchelated salt of an aminopolycarboxylic acid such as a tetrasodium salt of cthylenediamine tetraacetic acid may also be used. e

The fixing agent and the bleaching agent indicated above are the necessary components for the blixing solution to be used in the process of this invention. However. the blixing solution of this invention may further contain other additives generally known in this area of the art as additives for ordinary blixing solutions e.g.. the blixing solution may contain a water-soluble thiocyanate such as ammonium thiocyanate. sodium thiocyanate. or potassium thiocyanate. or a silver halide solvent such as ammonium bromide. an alkali metal bro mide, an amine, a sulfite. and mercaptazoles such as 2.5-dimercapto-thiadiazole and mercaptotriazole.

The concentration ofthe thiosulfate in the blixing solution is generally about 5 to about 200 g/liter and the concentration of the ferric salt of the aminopolycarboxylic acid is generally about 5 to about 200 g/liter.

Typical examples of such a blixing solution are disclosed in German Pat. No. 866,605; British Pat. No.-

l M14396; and German Pat. No. 966.410. Other examples of the blixing solution are illustrated in the color developing processings designated by main photographic cotnpanies in Europe as described on pages 122-] 23 and l'lo of The British Journal of Photography". i960.

During the use of the blixing solution. silver ions are formed. and if the silver ions are accumulated in the blixing solution in a high concentration. the blixing rate is reduced. For instance. the blixing rate of the com pletely blackened portion of a silver halide color photographic material (the blackened portion consisting of mixed crystals of about 0.5% silver iodide and 995% silver bromide) changes with a change in the silver ion concentration in the blixing solution as shown below:

Silver ion Blixing time ()xidation-retluction concentration potential (g/lilur) (mv vs SCE) O 4 min. sec. 8 2 min. '15 sec. (it) 5 8 min. sec. 92 X l'. min. ll] secv I33 (The composition of the blixing solution used in the above test was same as the composition described in 'Example I As will be understood from the above table. when reuse ofthe blixing solution by adding deficient compo- Therefore. if fixing of the silver halide photographic material is conducted prior to blixing. the amount of silver carried in the blixing solution is about At to about U) of the total amount of silver. and thus even in the case of processing a light-sensitive material containing a large amount of silver e.g.. about l0 g/m such as a color photographic negative film. the average silver ion Iconcentration'in the blixing solution at processing is at ,amost about 4 g/liter. which amount will not have a harmful influence on blixing processing.

. The absolute amount of silver thus entering the fix both (and then the blix bath) is thus seen to be about 2.0 g/m of material processed.

When color photographic light-sensitive materials :having a silver content of 1.5 g/m" are exposed. developed and blixed without fixing between development and blixing. the average silver ion concentration of the .sensitive materials. Since a color photographic paper usually has only a small amount of silver coated thereon. the latter process is convenient.

The silver ions carried in washing water after blixing or the silver ions formed in the fixing bath employed prior to blixing can be easily recovered by known processes. cg. electrolysis.

During the use of the blixing solution. the solution is diluted with water carried by the photographic materials being processed. and necessary chemicals are consumed and by-products are formed as a result of reac tion in the processing. Accordingly. chemicals are added to the blixing solution to compensate for deficient components. According to the process of this invention it is unnecessary to forcibly introduce oxygen into the blixing solution and thus the occurence of ex cessive oxidation is less. Therefore. the oxidation of sulfite as well as the accumulation of sulfate are lssened. which makes the control and maintenance of the concentration of the blixing solution easy. Further more. due to the lowered accumulation of by-products. it becomes unnecessary to dispose ofa part of the overflow solution in the regeneration step. and thus the blix ing solution can be regenerated completely or the total amount of the blixing solution can be regenerated and reused.

The amount of the deficient components to be added to the blixing solution depends upon the kind of photographic lightsensitive material. the kind of developing machine. and the developing conditions. but a stable processing is possible under each condition.

As mentioned above. the feature of the process of this invention is in the point of reducing the amount of silver to be blixed in the blixing operation but modifications of this invention to adopt the same to other processings and other photographic light-sensitive materi als than those described above will easily be made by persons skilled in the art. Therefore. the following discussion should not be taken as restrictive of the process of this invention.

The color developing solution used in combination with the process of this invention can generally be se lected from any of those used in. color photographic processings known to the prior art. and is generally an aqueous alkaline solution of an aromatic primary amine color developing agent containing. preferably. benzyl alcohol. Examples of such color developing agents are phenylenediamine derivative such as N.N- diethyl-p-phenylenediamine sulfate and other known aromatic primary amine color developing agents such as 4-amino-N-ethyl-N-Bhydroxycthylaniline sulfate. 3-methyl-4-amino-N-ethyl-B- methanesulfoamideethylaniline sesquisulfate monohydrate. 3-methyl-4-amino-Nethyl-N-B- hydroxyethylaniline sulfate. 3-methyl-4-amino-N.N- diethylaniline hydrochloride. and the like. The color developing solution can further contain a sulfite. an alkali metal carbonate. a bisulflte. a bromide. an iodide. an antifoggant. a developing accelerator. and a solvent such as diethylene glycol.

During the practice of the process of this invention. blixing is conducted after color development. and the techniques for reducing the silver amount to be blixed are applied. After blixing in this invention, the color photographic material thus processed may be processed. if necessary, in an image stabilization bath. Of course. in addition to the above fundamental steps conventional subsidiary baths such as a washing bath. a stopping bath. a hardening bath. a post-processing bath. an aldehyde neutralizing bath. etc.. may be added. if desired. between the aforesaid fundamental steps according to the nature of the color photographic materials to be processed. Furthermore. in the ease of applying the process of this invention to a reversal color development. a black and white development as a matter of course. conducted prior to color development.

The color photographic light-sensitive materials to be procesed by the process of this invention contain in the silver halide emulsion layers at least one type of a four equivalent coupler or a two equivalent coupler. Exemplary of four equivalent couplers as may be used in the present invention are those represented by the formula wherein R represents a substituted or unsubstituted alkyl group. a substituted or unsubstited aryl group. or a substituted or unsubstituted heterocyclic group and R' represents an alkyl group. a carbamyl group. at amino group, or an amide group. 1

Specific examples of such four equivalent couplers are shown below:

l-p-sec-amylphenyl-3-n-amyl-5-pyrazolone.

2-cyanoacetyl-5-(p-sec-amylbenzoylamino)cou marone. 2-cyan oacetyleoumaron'e-5-( N-n-amyl-p-- amylsulfoanilide). 2-cyanoacetylcoumarone-S-sulfone-N-nbutylanilide. l-p-laurylphenyl-3-methyl-5-pyrazolone. l-,8-naphthyl-3-amyl-5-pyrazolone. l-p-nitrophenol-3-n-amyl-5-pyrazolone. l-phenyl-3-acetylamino-5-pyrazolone. l-phe nyl-3-n-valeramino-S-pyrazolone. l-phenyl 3Z-chloroaceatylamino-S-pyrazolone, l-phenyl-3-(m-aminobenzyl )-amino-5-pyrazolonc. lp-phen0xyphenyl- 3-(p-t-amyloxybenzoyl )amino-S- pyrazolone, l-(2,4'.6-trichlorophenyl)-3-benzamido-5- pyrazolone. l-(2,4-dichlorophenyl)-3-[3"(2,4-di-tamylphenoxyacetamido)benzamido1-5- pyrazolone. and l-(2.4-dimethyl-6-chlorophenyl )-3-[3"-( 2", 4"-di'- t-amylphenoxyacetamido)benzamido1-5- pyrazolone.

In addition, the four equivalent couplers described in the specifications of British Pat. No. 1.142.553 and US. Pat. No. 3,337,344 are representative of couplers as may be used in the color photographic materials processed by the process of this invention.

Examples of four equivalent couplers giving yellow dyes such as benzoylaeetoanilide typc dyes and pivaloylacetoanilide type dyes are the yellow couplers disclosed in the specifications of British Pat. No. L] l3.()38 and U.S.Pat. No. 3.337.344. Furthermore, the following yellow couplers may also be employed for the above purpose:

a-{3-[a-(m-pcntadecylphenoxy)butylamidolbenzoyl}-2-chloroacetoanilide.

methoxyacetoanilide.

a- {3-[a-( 2.4-di-t-amylphenoxy )butylamida lbenzoyll'-2-chloroacetoanilide. 2-chloro-3-[2.4-di-t-amylphenoxy)butylamido1benzoylacetoanilide. a-{3-[oz-(2.4-di-t-amylphenoxy)acetamidolbenzoyl} benzoylacettmnilide. and a-pivalyl-Z.5-dichloro-4-I N'-( n-octadecyl )-N- methylsulfamyl]-acetoanilide.

The above couplers are only exemplary of the four equivalent couplers which maybe incorporated in the silver halide emulsion layers of color photographic materials to be processed by the process of this invention. and the invention is not to be construed as limited thereto.

Examples of two equivalent couplers as can be used in the color photographic materials processed by the process of this invention are shown in the specification of U.S. Pat. No. 3.582.322. along with additional useful four equivalent couplers and developing agents.

The process of this invention can be applied to processing silver salt color photographic materials in general. such as color negative films. color papers, color positive films. color reversal cinne films, and color reversal TV films.

Therefore. the types of silver halide and protective colloids used in the color photographic light-sensitive materials to be processed in the process of this inven- EXAMPLE 1 A commercially available color paper*, was processed according to the process of this invention using a small automatic developing machine.

*(LP 8905-Type color paper. made by Fuji Photo Film Co.. Ltd.

The developing steps employed in this example were as follows:

Color development 24C. 6 min. Stop l'ixing 2 min. Water washing 2 min. lilixing 2 min. Water washing 2 min, Oxidation 2 min. Water washing 2 min. Stabilization 2 min. Drying The compositions of the processing baths used in the above steps were as follows:

Color developing solution: Benzyl alcohol Dicthylene glycol Sodium hydroxide Sodium sull'ite Potassium bromide Sodium chloride Borax Hydroxylamine sulfate lithylenediamine tetraacetic acid 4-/ \mino-3-methyl-N-ethyl-N-(B- re oo rn riuarrrnmo:

Continued sull'oneamidoetliyl )anilinc sesqui sulfate monohydrate 5.0 g Water added to make 1 liter. Stop l'i\int solution:

Sodium tliiosullate 70 g Ammonium tliiosulfate I700 30 cc Sodium acetate g Acetic acid 30 cc Potassium alum )5 g Water added to make I liter. lllising solution:

Sodium l'erric eth \'lenediamine tetraacetic acid monohydrate 33 g Z-Sodium ethylenediamine tetraacetate dihydrate 2 g Sodium carbonate monoh \'drate l7 g Sodium sullite 5 g 70'/: Aqueous aounonium thiosull'ate solution Boric acid The pH of the solution was adjusted to 5.5. and then water was added thereto to make the total volume one liter.

The fresh blixing complementary solution, the use of which will later be described. had the following composition:

Sodium ferric eth \'lenedi-.imine tetraacctic acid monohydrate 40.5 g l Sodium etltylenediaminc tetraacetate dihydratc i g Sodium carbonate monoh \'drate 24 g Sodium sullite X g 70'.) Aqueous ammonium thiosull'atc solution I50 ml ltorie acid It) g The pH of the fress blixing complementary solution was adjusted to 5.4. and water was added to make the total volume one liter.

The processing treatments described above were continuously carried out using the compositions de scribed above while complementary make up solutions were added to the tanks of the machines as necessary in accordance with prior art techniques except for the blixing solution, which was specially treated as described below. i

In the blixing step. a complementary blixing solution was continuously replenished to the blixing solution tank at rate of900 ml for every I m'-' of color paper processed. As the starting complementary solution, liters ofthe fresh blixing complementary solution shown described above was employed. By the replenishments.

blixing solution in the same amount as the replenished solution added continuously overflowed from the tank.

The overflowed solution was stored in a collection ation. which was then replenished at the same rate as above.

The composition of the first complementary solution was then the same as the fresh complementary solution as shown in the following table.

Additive for Amount per Amount of the first regeneration liter of overeomplementanv solution flow solution for regeneration (analyzed values) Sodium ferric (g) eth \'lenediamine )0 40.5 g!) tetraacetate monohydrate Disodium ethylenediamine tetraacetate [.0 3.0 g/l dihydrate Sodium carbonate hydrate 8.0 24 g/l Sodium ammonium 36 I50 ml/liter as a lltiosttllltte aqueous solution olammonium thiosullate Boric acid 3 l0.0 g/l pH 5.40

The same operations of storing the overflow solution. adding the additives for regeneration and then replenishing the complementary solution for regeneration were constantly repeated during the processing. During the operation. when the total atnount of the replenished solution was the same as the volume of the tank (in other words. when one round was terminated). the blixing solution in the tank was sampled and analyzed. The results obtained are as follows:

Concentration of Components in Solutions Sampled Round no. Analyzed Components A I! D F.

(all) (g/l) (ml/I) (g/l) (all) I 35.0 0.08 0.03 (H4 2 34.) 0.68 HH 0.26 L20 3 3(1.) l.2l 101 0.47 2.12 4 37.2 L68 I02 0.64 2.91 S 38.0 209 I02 0.79 3.62 h 38.8 2.45 I03 0.93 4.24 7 38.5 2.75 I03 [.05 4.72 It 40.) 3.02 I03 l.l5 5.24 9 40.6 3.26 I04 1.24 5.64 l() 4L0 3.48 104 1.32 5.99 I) 4L4 3.64 I05 1.39 6.37 12 4L8 3.80 I05 1.45 6.58 13 42d 3.90 [05 1.50 \Ll'il l4 42.4 3.95 1.54 7.0) I5 4211 4.00 105 1.58 7.20 20 43.4 4.05 I06 [.70 7.80

A: The total iron salts of ethylenediamine tetra-acetic acid (as sodium t'errii: cthylcncdiamine \ctracetic acid monoliydratc).

I): Sodium l'crrous etliylenediamine tetraacetic acid.

(z Thiosullates tas 70'; ammonium salt solution).

I). Silver salts (as Ag).

Ii: Sulfate radicals (as NtuSOJ As shown in the above table. the composition of the solution gradually approached steady state as the number of rounds the solution was used increased. and no significant changes in composition occurred at the 20th round. At this round. the accumulated amount of by products was slight with respect to sulfate radicals. ferric ethylencdiamine tetraacetate. and silver salt. and further the reduction in blixing rate was so slight (e.g.. the period of time required for finishing blixing was about 85-90 seconds when the solution in the tank at the 20th round was used. while the period of time in the ease of using a fresh complementary solution was 75 seconds) that the accumulated solution in the tank could be used repeatedly in blixing for the blixing period of I20 seconds defined for the developing machine.

The necessary components of the blix bath and the replenishing solution are the bleaching agent and the fixing agent. Other components are optional. l

The amounts of the bleaching agent and the fixing agent in the blixing bath have been heretofore de scribed (about 5 to about 200 g/liter for each). The amount of these components in the replenishing solution is usually about 1.0 to about 1.6 times by weight the amount in the blixing bath. Obviously. it is preferred to at least return the blix bath to its original strength.

The volume of the replenishing solution added is generally from about 200 to about 1250 cc/m" of material processed. preferably 500 800 cc/m It will be clear to one skilled in the art, however. that values outside of the above ranges can be used if one is willing to suffer. some inefficiencies in the blixing or regeneration.

It has been confirmed that by conducting such a regeneration process: (1) the amount of chemicals used in the process is reduced to A; to of that in the case of not conducting the regeneration;(2) the water contamination due to waste solution disposal from the developing machine is reduced (that is to say. the BOD and COD as well as the heavy metals content are reduced); and (3) the process is advantageous as compared the process described in Japanese patent application open to public inspection No. 781/71 as shown below.

For purposes of comparison the process was conducted using the same king of color paper as was used in the above process while omitting the stop-fixing step.

The overflow solution of the blixing solution was introduced into a cartridge filled with metallic iron wool.

Two such cartridges were connected in series. The solution from the cartridges contained ferrous ions formed from the complete reduction of ferric ions. The solution was introduced into an aeration tank equipped with an air sparger and air was blown into the solution for about one hour. By the aeration the ferrous ions were converted into ferric ions. the solution changing dark red. At the same time it was confirmed that the oxidation reduction potential of the solution had been recovered. Deficient components (make up components needed to regenerate the solution) such as disodium ethylenediamine tetraacetate dihydrate. sodium ammonium thiosulfate. sodium sulfite. sodium carbonate. and boric acid were added to the solution to provide a complementary solution. which was reused.

By repeating the above operation. the process was conducted for 50 days. However. on comparing this process with the process of our invention. we confirmed that. the process of our invention is superior to the above process in the following points:

1. In the process of this invention silver removal and air blowing are unnecessary and it is only necessary to add deficient components for regeneration. That is to say. the process ofour invention is quite simple and can be easily conducted. On the other hand. the comparison process as shown above requires a long period of time for regeneration. as well as cartridges and an aeration tank. which makes the conventional process disadvantageous as compared with the process of our invention. I

2. In the comparison process the blixing rate is greatly reduced if the aeration is insufficient due, perhaps. to the presence of a large amount of ferrous ions.

On the other hand. aeration is unncessary in the process of our invention and thus the process of our invention is not accompanied by the aforementioned problems.

3. If. on the other hand. aeration is conducted sufficiently in the comparison process. in addition to the oxidation of ferrous ions. significant oxidation of sulfite oxxurs as a side reaction. and thus a large amount of sulfite is required as an additive for regeneration. The process of our invention is not accompanied. by such problems based on the oxidation of sulfite.

4. In the comparison process. iron was dissolved in the solution from the steel wool in the cartridge. and when the regeneration process was repeatedly conducted the concentration of iron salt increased rapidly. and could not be maintained constant. In this case problems such as the precipitation of iron salt and the formation of brown stains on the color paper oceured. In order to solve those problems. it was necessary to increase the amount of ethylene diamine tetraacetate added for regeneration and to discard about 20% of the overflow solution during each regeneration operation. Accordingly. in the comparison process. the amount of chemical consumed becomes layer. which makes the process disadvantageous as compared with the process of this invention. The comparison process is also disadvantageous from the point of causing contamination, and further it is difficult to control the amount of the overflow solution discharged.

5. When the comparison process was conducted without discharging overflow solution. the process became inoperable in only three rounds.

6. Because the dissolution rate of thesteel wool was high. the amount of overflow solution which could be processed using 1 kg of steel wool in the comparison process was only 200 liters. Although iron is an expensive metal. such a high rate of iron consumption is disadvantageous.

As mentioned above. while the comparison process illustrated above includes various faults. the process of the present invention is a simple, convenient and stable process which is not accompanied by such faults.

The process of the present invent-ion requires a stopfixing step in one embodiment, but the addition of such a step is a very slight disadvantage as compared to the above-mentioned various advantages of this invention. Furthermore. in the process of this invention. silver can be recovered in the stop fixing process and during water washing. andthus the'efficiency of silver salt recovery can be maintained at a high level.

EXAMPLE 2 A color negative film comprising a sensitive silver halide emulsion layer containing gelatin and silver iodobromide on a cellulose acetate film (coated silver amount of 9.2 g/m) was processed in a small automatic developing machine according to the process of this invention. The processes employed in this example were as follows: v v

Processing step:

Color development 14C l2 min. Stopping 4 min. Hardening fixing 4 min. Water washing 4 min. Blixing 6 min. Water washing 4 min. Post processing 8 min.

-Continued Water washing X min.

Drying The compositions of the processing baths used in the above processing steps were as follows: It

('olor developing solution: Bemyl alcohol cc I Sodium hydroxide [1.5 g Diethylene glycol 3 cc ll) Sodium hexametaphosphate 2 g Sodium sullite 2 g Potassium brotnide 2 g 4'Amino-Z-methyl-N-ethy|-B hydroxyethylaniline sesquisulfate monohydrale 5 g Metaboric acid ()5 g Navox (Sodium metaborate) 77 g Water to make to one liter. Stopping solution: Sodium acetate 30 g Glacial acetic acid 8 ml Water to make one liter. Hardening fixing bath: Sodium hexametaphosphate l g Sodium sulfite 5 g Sodium thiosulfate I50 g Sodium acetate 20 g Acetic acid ti ml Potassium alum [5 g 7 Water to make one liter. Blixing bath: Sodium ferric ethylenediaminc tetraaeetic acid monohydratc 33 g Z-Sodium etliylenediamine tetraacctic dihydrate 2 g BUItIXlOH O 5 g Boric acid H) g Sodium sulfite 5 g 70% Aqueous ammonium thiosulfatc lfitl ml soln. 'l'hiourca 5 g pH adjusted to 6.0 Water to make one liter.

The amount of each component in the complementary solution for blixing was l.5 times the amount of each component in the flixing solution.

As in Example 1. the fresh complementary solution 40 was used in only the first round. and thereafter a complementary solution prepared by adding the additives necessary for regeneration to the overflow solution was used. The volume of the complementary solution per round was 20 liters. 4g

the accumulated by-products was far below a level which would have a harmful influence when regeneration is repeated.

For the sake of comparison. the above experiment was followed while replacing the blixing bath in the above process by a hardening bath consisting of an alkaline aqueous solution of formalin. thereby yielding another process outside the process of this invention. In this comparison experiment, silver salt rapidly accumulated in the blixing bath with an increase in the number of regeneration rounds. that is to say. the amount of accumulated silver salt reached 7.5 g/liter at the second round. l4 g/liter at the third round. and 18 g/liter at the fourth round. Further. the content of ferrous ions was large. the blixing rate was low. and the removal of silver from the processed sample was imperfect.

As another comparison experiment. the above comparison experiment was followed except the overflow solution of the blixing solution was further passed through cartridges filled with steel wool and then aer ated in an aeration tank by blowing air into the solution therein. In this experiment. the sample processed had good image qualities. but various disadvantages as shown in the comparison experiment in Example I were observed from the point of maintaining constant bath compositions.

EXAMPLE 3 This example shows that the process of this invention can be applied directly, without conducting pre-fixing, to a light-sensitive material having a reduced amount of Amount per liter of over llow solution Additive for regeneration First complementary solution for regene ration (analytical When the process of this invention was continuously conducted using the afore-indicated baths. the reaction was finished in a definite period of time without any unusual influence on the qualities of the processed products and at a sufliciently high blixing rate. The compositions at the l()th and l5th rounds of the operation were as shown below. illustrating that the amount of silver coated thereon. That is to say. developing processings the same as in Example l were conducted using color papers having coated silver amounts of L56 g/m and 3.12 glm respectively. in this case. however. fixing before blixing was omitted.

The concentration of each component changed during continuously repeating the regeneration process in the same manner as in Example 1. except the concentration of silver salt. The changes in the concentration of silver salt are shown in the following table:

Concentration of silver salt lg/l 1n the blixing step. the initial blixing time was 75 seconds for the color paper having silver coated in an amount of 1.56 g/m which was increased about to 105 seconds at the th round. However. blixing was finished in a definite period of time and good results were obtained. On the other hand. in case of using color papers having silver coated in an amount of 3.12 g/m the initial time required for finishing blixing was 90- 100 seconds, and further the blixing time increased rapidly while repeating the processing cycle, whereby blixing became insufficient. In other words, when the amount of silver in the color papers was reduced, the blixing rate for the color papers was high and the accumulation of silver salt in the blixing solution repeated regenerations was low, which makes the application of the process of this invention possible.

EXAMPLE 4 The same continuous regeneration process as in Example l was followed using a Noritsu-type Four-File Paper Automatic Developing Machine (made by Noritsu Koki K. K.) and commercially available CLP 8905-Type color paper (made by Fuji Photo Film Co.) for 2 months. The developing machine was equipped with an air sparger in the blixing tank to assist the agita tion of the solution in the tank. and one second air bursts were made at a rate of once every 10 seconds.

The results of the development were good. the change in composition of the blixing solution showing almost the same tendency as in Example 1. but the amount of accumulated ferrous salt in the tank was about /2 of the amount in the case of Example l. Thus. it will be understood that the combined use of an air sparger and the process of this invention is one prefered embodiment of this invention.

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 modification can be made therein without departing from the spirit and scope thereof.

What is claimed is:

l. In the blixing ofcolor photographic materials using a blixing solution. an improved process of regenerating used blixing solution which comprises:

maintaining the silver salt concentration. expressed in terms of the amou nt ft if silver ions. at level less than about LOg/Iiter iri' the blixing solution and thereafter adding components to the used blixing solution to make up for those in the blixing processing without removing silver salt from the used blixing solution. thereby providing a composition at least equivalent to that of the blixing solution prior to use for blixing additional color photographic materials. wherein said maintaining is accomplished by subjecting the color photographic materials. after color development. to fixing prior to blixing to preliminarily remove a substantial portion of soluble silver salt from the color photographic materials or wherein said maintaining of the amount ofsilver salt is obtained by reducing the amount of coated silver in the initial color photographic materials to below 2.0g/m'-'.

2. The process as set forth in claim 1 in which said blixing solution contains (a) at least one member from the group consisting of a ferric complex salt of an aminopolycarboxylic acid. a cobalt (lll) complex salt of a polyammine. a cobalt (lll) complex salt of nitrous acid. and a water-soluble ferric salt as a bleaching agent; and (b) a thiosulfate as at fixing agent.

3. The process as set forth in claim 1 in which the color photographic materials are. after color development. subjected to fixing prior to blixing to preliminarily remove a substantial portion of soluble silver salt from the color photographic materials.

4. The process of claim 1 in which the maintaining is conducted by reducing the amount of coated silver in the initial color photographic materials to below 2.0g/m

5. The process of claim 2 wherein the blixing solution comprises a bleaching agent and at fixing agent each present in an amount of from about 5 to about 200 g I of blixing solution. and components are added to the spent blixing solution so as to maintain these ranges during blixing,

6. The process of claim 3 wherein fixing is conducted so as to reduced the amount of silver carried into the blixing solution to about A to about 1/6 of the total amount of silver present in the color photographic material.

7. The process of claim 1 wherein the absolute amount of silver entering the blixing solution is less than about 2 g/m of color photographic material processed.

8. The process of claim 5 wherein the components which are added to the blix solution to make up for those used in the blixing processing are added in an amount of from 1.0 to 1.6 times the amount present in the blix solution. thereby at least maintaining the con centration of the components in the blix solution.

9. The process of claim 8 wherein the components are added in an aqueous solution at a rate of from about 200 to about 1250 cc/m of color photographic material process.

10. In the process of color photographic materials. an improved process of regenerating a blixing solution which consists essentially of:

a. maintaining the amount of silver salt expressed as silver ion reacted in the blixing solution at a value less than 10 g/l of blixing solution;

b. removing spent blixing solution from the blixing treatment and regenerating the spent blixing solution by adding thereto make up components in an amount at least equal to the components of the blixing solution consumed in the blixing operation to provide a composition at least equivalent to that l7 oi the initial blixing solution composition. without removing silver salt from the blixing solution;

c. returning the regenerated blixing solution oi step (b) to the biixingtreatment for the processing oi additional color photograhpic materials.

d. repeating steps (b) to) while observing the condition recited in step (a). wherein said maintaining is accomplished by subjecting the color photographic materials after color development. to fixing prior to blixing to preliminarily remove a substantial portion oi soluble silver salt from the color photographic materials or wherein said maintaining of the amount ofsilver salt is obtained by reducing the amount of coated silver in the initial color photographic materials to below 2.()g/m 11. The process ot'elaim 10 wherein the regenerated blixing solution returned to the blixing treatment contains from about 1.0 to about l.6 times an amount of 18 bleaching agent and fixing agent present in the blising bath. on a unit volume basis. and the regenerated blixing solution is returned to the blixing treatment in an amount of from about 200 to about 1250 ce/m'- otcolor photograpi'iic material subjected to the biixing treatment.

12. The process oiclaim ll wherein the blixing bath comprises from about 5 to about 200 g I oi bleaching agent and from about 5 to about 200 g I oi iixing agent.

13. The process oiclaim 10 wherein condition (a) is maintained by fixing prior to blixing.

14. The process of claim 13 wherein condition (a) is maintained by processing a color photographic material without fixing. which color photographic material initially contained coated silver in an amount less than 2.0 g/m.

Claims

1. IN THE BLIXING OF COLOR PHOTOGRAPHIC MATERIALS USING A BLIXING SOLUTION, AN IMPROVED PROCESS OF REGENERATING USED BLIXING SOLUTION WHICH COMPRISES: MAINTAINING THE SILVER SALT CONCENTRATION, EXPRESSED IN TERMS OF THE AMOUNT OF SILVER IONS, AT LEVEL LESS THAN ABOUT 10G/LITER IN THE BLIXING SOLUTION AND THEREAFTER ADDING COMPONENTS TO THE USED BLIXING SOLUTION TO MAKE UP FOR THOSE IN THE BLIXING PROCESSING WITHOUT REMOVING SILVER SALT FROM THE USED BLIXING SOLUTION, THEREBY PROVIDING A COMPOSITION AT LEAST EQUIVALENT TO THAT OF THE BLIXING SOLUTION PRIOR TO USE FOR BLIXING ADDITIONAL COLOR PHOTOGRAPHIC MATERIALS, WHEREIN SAID MAINTAINING IS ACCOMPLISHED BY SUBJECTING THE COLOR PHOTOGRAPHIC MATERIALS, AFTER COLOR DEVELOPMENT, TO FIXING PRIOR TO BLIXING TO PRELIMINARILY REMOVE A SUBSTANTIAL PORTION OF SOLUBLE SILVER SALT FROM THE COLOR PHOTOGRAPHIC MATERIALS OR WHEREIN SAID MAINTAINING OF THE AMOUNT OF SILVER SALT IS OBTAINED BY REDUCING THE AMOUNT OF COATED SILVER IN THE INITIAL COLOR PHOTOGRAPHIC MATERIALS TO BELOW 2.0G/M2.

2. The process as set forth in claim 1 in which said blixing solution contains (a) at least one member from the group consisting of a ferric complex salt of an aminopolycarboxylic acid, a cobalt (III) complex salt of a polyammine, a cobalt (III) complex salt of nitrous acid, and a water-soluble ferric salt as a bleaching agent; and (b) a thiosulfate as a fixing agent.

3. The process as set forth in claim 1 in which the color photographic materials are, after color development, subjected to fixing prior to blixing to preliminarily remove a substantial portion of soluble silver salt from the color photographic materials.

4. The process of claim 1 in which the maintaining is conducted by reducing the amount of coated silver in the initial color photographic materials to below 2.0g/m2.

5. The process of claim 2 wherein the blixing solution comprises a bleaching agent and a fixing agent each present in an amount of from about 5 to about 200 g / l of blixing solution, and components are added to the spent blixing solution so as to maintain these ranges during blixing.

6. The process of claim 3 wherein fixing is conducted so as to reduced the amount of silver carried into the blixing solution to about 1/4 to about 1/6 of the total amount of silver present in the color photographic material.

7. The process of claim 1 wherein the absolute amount of silver entering the blixing solution is less than about 2 g/m2 of color photographic material processed.

8. The process of claim 5 wherein the components which are added to the blix solution to make up for those used in the blixing processing are added in an amount of from 1.0 to 1.6 times the amount present in the blix solution, thereby at least maintaining the concentration of the components in the blix solution.

9. The process of claim 8 wherein the components are added in an aqueous solution at a rate of from about 200 to about 1250 cc/m2 of color photographic material process.

10. In the process of color photographic materials, an improved process of regenerating a blixing solution which consists essentially of: a. maintaining the amount of silver salt expressed as silver ion reacted in the blixing solution at a value less than 10 g/l of blixing solution; b. removing spent blixing solution from the blixing treatment and regenerating the spent blixing solution by adding thereto make up components in an amount at least equal to the components of the blixing solution consumed in the blixing operation to provide a composition at least equivalent to that of the initial blixing solution composition, without removing silver salt from the blixing solution; c. returning the regenerated blixing solution of step (b) to the blixing treatment for the processing of additional color photograhpic materials; d. repeating steps (b) - (c) while observing the condition recited in step (a), wherein said maintaining is accomplished by subjecting the color photogrAphic materials after color development, to fixing prior to blixing to preliminarily remove a substantial portion of soluble silver salt from the color photographic materials or wherein said maintaining of the amount of silver salt is obtained by reducing the amount of coated silver in the initial color photographic materials to below 2.0g/m2.

11. The process of claim 10 wherein the regenerated blixing solution returned to the blixing treatment contains from about 1.0 to about 1.6 times an amount of bleaching agent and fixing agent present in the blixing bath, on a unit volume basis, and the regenerated blixing solution is returned to the blixing treatment in an amount of from about 200 to about 1250 cc/m2 of color photographic material subjected to the blixing treatment.

12. The process of claim 11 wherein the blixing bath comprises from about 5 to about 200 g / l of bleaching agent and from about 5 to about 200 g / l of fixing agent.

13. The process of claim 10 wherein condition (a) is maintained by fixing prior to blixing.

14. The process of claim 13 wherein condition (a) is maintained by processing a color photographic material without fixing, which color photographic material initially contained coated silver in an amount less than 2.0 g/m2.