|
(11) | EP 0 556 716 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
|
|
|
|
|||||||||||||||||||||||||||
| (54) | Color developer for silver halide color photographic light-sensitive material |
| (57) Disclosed is a color developer for a silver halide color photographic light-sensitive
material comprising at least one compound represented by Formula 1, and a color developing
agent in an amount not less than 0.02 mol/I, and a compound selected from the group
consisting of an aromatic sulfonic acid and an aromatic compound having a -O-S03-R group in an amount not less than 2.5 mol per mol of a color developing agent: wherein
R represents a hydrogen atom, a sodium atom, a potassium atom, an ammonium group or
an lithium atom:
wherein A and B each represent a linear or branched alkylene group, n and m each represent an integer of 0 to 100, provided that both A and B are not 0, and A or B is a linear or branched alkylene group having 3 or more carbon atoms when n + m = 1. The color developer improves the maintenance efficiency of an automatic processor. |
FIELD OF THE INVENTION
[0001] The present invention relates to a color developer for silver halide color photographic light-sensitive materials. More specifically, the present invention relates to a color developer for silver halide color photographic light-sensitive materials, which forms no deposits in a color developing replenisher even when a color developing agent is dissolved therein at a high concentration, has a capability of performing rapid and stable processing at a replenishing amount smaller than that of a conventional color developer, and improves the maintenance efficiency of an automatic processor to a large extent.
BACKGROUND OF THE INVENTION
[0002] The processing of a light-sensitive material basically comprises two processes of color development and desilverization, and desilverization comprises a bleaching process and a fixing process, or a bleach-fixing process. Besides them, a rinsing treatment and a stabilizing treatment are performed as supplementary processes.
[0003] In color developing, exposed silver halides are reduced to silver and, at the same time, an oxidized aromatic primary amine developing agent reacts with a coupler to form a dye. In this process, halogen ions generated by reduction of silver halides are dissolved and accumulated in a developer. In addition, components contained in a silver halide photographic light-sensitive material, such as a developing inhibitor, are also dissolved and accumulated in the developer.
[0004] Further, in the desilverizing process, the silver generated by developing is bleached by an oxidizing agent and, then, all silver salts are removed from the light-sensitive material as soluble silver salts by use of a fixing agent. And the monobath bleach-fixing method is also practiced, in which bleaching and fixing are carried out concurrently.
[0005] In a color developer, a development inhibiting material is accumulated as described above, while processing of photographic light-sensitive materials is carried on; on the other hand, a color developing agent and benzyl alcohol are consumed, or accumulated in light-sensitive materials and brought out of the color developer, and thereby concentrations of these components are lowered there. Accordingly, when a large amount of light-sensitive materials are continuously processed in an automatic processor, an appropriate measure must be taken to keep the concentration of the components of a color developer within a prescribed range, in order to avoid a fluctuation in finishing behavior of development due to change in component concentration.
[0006] As such a measure, it is usual to supply a replenisher for making up for the deficiency of components and diluting the unnecessary increase of components. The supply of a replenisher, however, inevitably yields a large amount of overflown liquid to be eventually discarded and, thereby, raises serious economical and environmental problems. Therefore, in order to reduce the amount of overflown liquid discarded, there are proposed and practiced in recent years various methods such as regeneration of a developer by use of ion exchange resins or electrodialysis, replenishment of a concentrated developer in a small volume, and addition of a regenerator to an overflown liquid to reuse it as a replenisher.
[0007] The generation of a developer is achieved by removing bromides, accumulated unnecessary components, and making up for deficient components. But the regeneration using ion exchange resins or electrodialysis has a problem that the developability of a light-sensitive material is impaired unless the amount of each developer component is kept constant by means of quantitative chemical analysis; therefore, it needs complicated procedures, making it difficult to introduce the method in small-sized processing laboratories and mini-laboratories lacking in technical skills. In addition, the method requires a large sum of initial investment.
[0008] The addition of a regenerator to an overflown liquid to reuse it as a replenisher requires no particular skill, but it needs additional installations such as stock tanks and, moreover, has a disadvantage of requiring a procedure which is difficult to carry out in processing laboratories. Accordingly, this method can be hardly introduced to mini-laboratories, either. On the contrary, the low replenishment at high concentration does not particularly need addition of new apparatus and handling is easy; therefore, this method is very suitable for small-sized processing laboratories including mini-laboratories.
[0009] However, this method also has a couple of disadvantages. For example, the usual color developing agent employed in development of a color photographic light-sensitive material is not necessarily sufficient in solubility in a pH range necessary to form dyes; accordingly, the developing agent is deposited when added in excess of a specific concentration.
[0010] When such deposition occurs in a replenisher, a strainer of a replenishing pump is clogged up; therefore, pumping action is hindered and, eventually, the pump itself is damaged.
[0011] Further, the mini-laboratory market is growing in recent years with the expansion of the photographic industry. But the processing amount in such laboratories is very small when compared with that in conventional large laboratories.
[0012] When processing is run intermittently over a long time, in such mini-laboratories, using a processing solution containing a color developing agent at a high concentration, deposition occurs at times on a rack or rollers of the color developing tank due to evaporation of a processing solution or spattering of the solution taken out by a light-sensitive material. And this causes coloring in white portions of a color print, lowering in optical density, and deterioration in sensitivity; as a result, the commercial value of a light-sensitive material is heavily reduced.
[0013] Japanese Pat. O.P.I. Pub. Nos.42154/1987 and 42155/1987 propose addition of a specific water-soluble surfactant to a color developer as a preventive measure against deposition on a rack and rollers in a color developing tank of an automatic processor. But this is not a very effective method.
[0014] In practice, such deposits are removed by washing a color developing tank before the start of processing or by sending cleaning paper into the tank. These procedures, however, require not only day- by-day maintenance work but a person to manage the job; this is a large impediment to further expansion of the mini-laboratory market.
[0015] British Pat. No.669,505 discloses a method for dissolving a p-phenylenediamine type color developing agent in an alkaline water at a high concentration, with the aid of a benzenesulfonic acid derivative. But the concentration of the color developing agent obtained by this method is not high enough to achieve a small-volume and high-concentration replenishment and a rapid processing which are intended by the present invention; in addition, this method cannot effectively prevent a color developing agent from being deposited in an automatic processor.
[0016] Taking notice of the foregoing matters, the present inventors have made a study in particulars and found that the combination according to the present invention can protect a color developer from deterioration even when stored for a long time in an automatic processor run with a very small processing amount, prevent developer components from depositing or caking on automatic processor's members, and markedly simplify maintenance of an automatic processor. This is, indeed, an unexpected outcome for the present inventors.
OBJECT OF THE INVENTION
[0017] Accordingly, the object of the present invention is firstly to provide a color developer for silver halide color photographic light-sensitive materials which can stably maintain photographic properties even when used in rapid processing or processing with low replenishment over a long period of time, and secondly to provide a color developer for silver halide color photographic light-sensitive materials which eases maintenance of an automatic processor and is free from caking of deposits and damages of automatic processor's members caused thereby.
CONSTITUENTS OF THE INVENTION
[0018] The color developer for silver halide color photographic light-sensitive materials according to the invention contains at least one of compounds represented by formula [1], a color developing agent in an amount not less than 0.02 mol/I, and an aromatic sulfonic acid or an aromatic compound having a -O-S03-R group in an amount not less than 2.5 mol per mol of color developing agent, wherein R represents a hydrogen atom, a sodium atom, a potassium atom, an ammonium group or an lithium atom.
[0019] In the formula, A and B each represent a linear or branched alkylene group; n and m each represent an integer of 0 to 100, provided that both A and B are not 0 concurrently, and A or B is a linear or branched alkylene group having 3 or more carbon atoms when n + m = 1.
[0020] To produce the intended effect of the invention as much as possible, it is preferable that the aromatic sulfonic acid or the aromatic compound having a -O-S03-R group contained in the color developer be a compound represented by the following formula [2] or [3].
[0021] In the formula, at least one of A to F is a sulfonic acid group or -O-S03-R group, and each of the rest represents a hydrogen or halogen atom or a saturated or unsaturated alkyl group, wherein R represents a hydrogen atom, a sodium atom, a potassium atom, an ammonium group or an lithium atom.
[0022] In the formula, at least one of G to N is a sulfonic acid group or -O-S03-R group, and each of the rest represents a hydrogen or halogen atom or a saturated or unsaturated alkyl group, wherein R represents a hydrogen atom, a sodium atom, a potassium atom, an ammonium group or an lithium atom.
[0023] In the invention, the amount of the compound represented by formula [1] contained in the color developer is preferably 2.0 to 100 g/I, especially 5.0 to 50 g/I.
[0025] The color developer for silver halide color photographic light-sensitive materials according to the invention contains at least one of compounds represented by formula [1], a color developing agent in an amount not less than 0.02 mol/I, and an aromatic sulfonic acid or an aromatic -O-S03-R group in an amount not less than 2.5 mol per mol of color developing agent and, thereby it can prevent a developing agent in color developer from depositing, maintain stable photographic properties over a long period even when used in rapid processing or small-volume replenishment processing, and markedly simplifies maintenance of an automatic processor because of its capability of preventing deposition or caking of solid matters on members of an automatic processor.
[0029] The compounds represented by formula [1] are added in the color developer within the range of preferably 2.0 to 100 g/I, especially 5.0 to 50 g/I.
[0030] The aromatic sulfonic acid or the aromatic compound having a -O-S03-R group, used in the invention is a compound in which a salt of sulfonic acid or a -O-S03-R group is linked directly with an unsaturated, conjugated ring having aromaticity. There may be one or more sulfonic acid groups or -O-S03-R groups, wherein R represents a hydrogen atom, a sodium atom, a potassium atom, an ammonium group or an lithium atom. The ring having aromaticity may contain a heteroatom or may have any substituent. Such a compound may contain a plurality of rings with aromaticity or may be a polymer. Salts thereof include salts of alkali metals, such as lithium, sodium, potassium, and ammonium salts.
[0031] Preferred aromatic sulfonic acids and the aromatic compound having a -O-S03-R group are those represented by the above formula [2] or [3].
[0032] In formula [2] or [3], the saturated or unsaturated alkyl group represented by A to F or G to N is preferably one having 1 to 10 carbon atoms, and it may be either a linear one or a branched one.
[0033] The following are typical examples of the compounds represented by formula [2] or [3], but usable ones are not limited to them. Though these exemplified compounds are shown as sodium salts for convenience' sake, part or all of the sulfonic acid groups or R of -O-S03-R groups contained in them may be other types of salts.
[0034] The addition amount of the aromatic sulfonic acid or the aromatic compound having a -O-S03-R group is necessarily not less than 2.5 mol, preferably not less than 3 mol per mol of color developing agent.
[0035] The content of sulfurous acid (or sulfite) in the color developer of the invention is not more than 2.0x 1 0-3 mol/I or less; the effect of the invention can be best produced when the content is zero. In processing a silver chloride rich light-sensitive material, a substantially zero sulfite content is preferred in view of developing properties; but, in order to prevent oxidation of a color developing agent used in a processing solution kit, a sulfite may be contained within the range not more than 2.0 x 10-3 mol per liter of color developer.
[0036] In the embodiment of the invention, it is preferable that a p-phenylenediamine-based compound having a hydrophilic group be used as a color developing agent, for its capabilities of producing the effect of the invention and preventing fogs.
[0037] The p-phenylenediamine-based compound having a hydrophilic group is advantageous over a p-phenylenediamine compound having no hydrophilic group, such as N,N-diethyl-p-phenylenediamine, in that it forms no stain on a light-sensitive material, sparingly produces eruptions on the skin and has a capability of achieving the objects of the invention effectively when incorporated in the color developer of the invention.
[0038] The foregoing hydrophilic group includes those substituted, by a number of at least one, on the amino group or the benzene ring of a p-phenylenediamine compound; preferred examples thereof are
(m and n each are an integer of 1 or more)
[0039] Typical examples of such color developing agents include compounds (C-1) to (C-16) illustrated on pages 26-31 of Japanese Pat. Appl. No.203169/1990, compounds (1) to (8) on pages 29-31 of Japanese Pat. O.P.I. Pub. No.289350/1986, and compounds (1) to (62) on pages 5-9 of Japanese Pat. O.P.I. Pub. No.246543/1991; particularly preferred are compounds (C-1) and (C-3) illustrated in Japanese Pat. Appl. No.203169/1990, compound (2) in Japanese Pat. O.P.I. Pub. No.289350/1986, and compound (1) in Japanese Pat. O.P.I. Pub. No.246543/1991.The above color developing agents are usually used in the form a hydrochliride, a sulfate salt, a nitrate salt, phosphate salt, or other salts.
[0040] To produce the intended effect of the invention, the amount of a color developing agent must be not less than 2.0x10-2 mol per liter; preferably, it is not less than 2.2x10-2 mol per liter.
[0041] In the color developer of the invention, there are preferably employed, in place of hydroxylamine which has been conventionally used as a preservative, organic preservatives such as the hydroxylamine derivatives described in Japanese Pat. O.P.I. Pub. Nos.146043/1988, 146042/1988, 146041/1988, 146040/1988, 135938/1988, 118748/1988; and the hydroxamic acids, hydrazines, hydrazides, phenols, a-hydroxyketones, a-aminoketones, sugars, monoamines, diamines, quaternary ammonium salts, nitroxy radicals, alcohols, oximes, diamide compounds and condensed-ring amines described in Japanese Pat. O.P.I. Pub. No.62639/1989.
[0042] In one preferred embodiment of the invention, compounds represented by the following formula [A] or [B] are contained in the color developer, because these are suitable for rapid processing and useful in preventing bluing and, in addition, effectively prevent deposition of solid on the surface of a color developing bath.
[0043] The particulars of the compound represented by formula [A] are the same as those of the compound of formula [A] described on pages 50, 54 and 55 of Japanese Pat. Appl. No.17833/1990. Preferred examples of such compounds are shown below.
[0044] Exemplified compounds of formula [A]:
A-1 to A-15: the same as compounds A-1 to A-15 on pages 51-53 of Japanese Pat. Appl. No.178833/1990.
A-16 to A-25: Exemplified compounds listed below
A-26 to A-49: the same as compounds A-16 to A-39 on pages 51-53 of Japanese Pat. Appl. No.178833/1990.
[0045] In formula [B], the particulars of R1 to R5 are the same as those of R11 to R1 of the formula [I'] described from the 1st to 16th lines on page 15 of Japanese Pat. Appl. No.127444/1990. The following are examples of the compound represented by formula [B], but suitable ones are not limited to them.
[0046] These compounds represented by formula [A] or [B] are generally used in the form of free amines, hydrochlorides, sulfates, oxalates, phosphates or acetates.
[0047] The concentration of the compound of formula [A] or [B] in the color developer is usually 0.2 g/I to 50 g/I, preferably 0.5 g/I to 30 g/I, and especially 1 g/I to 15 g/I.
[0048] Though hydroxylamine and the conventional organic preservatives may be used in combination with the compounds of formula [A] or [B], it is preferable that hydroxylamine be not used for better developing properties.
[0049] Besides the foregoing components, the color developer of the invention may contain the following developer components.
[0050] As alkali agents, sodium hydroxide, potassium hydroxide, silicates, sodium metaborate, potassium metaborate, trisodium phosphate, tripotassium phosphate and borax, for example, are used singly or in combination within a range to maintain enough pH stabilizing function without forming any precipitate. Further, for preparation reasons or for a higher ionic strength, there may be used salts such as disodium hydrogen phosphate, dipotassium hydrogen#phosphate, sodium hydrogen#carbonate, potassium hydrogen#carbonate and borates.
[0052] In formula [SI], A is a monovalent organic group, for example, an alkyl group having 6 to 50, preferably 6 to 35, carbon atoms (e.g.,hexyl, heptyl, octyl, nonyl, decyl, undecyl or dodecyl) or an aryl group substituted by an alkyl group having 3 to 35 carbon atoms or by an alkenyl group having 2 to 35 carbon atoms. Preferred examples of the group substituted on the aryl group include alkyl groups of 1 to 18 carbon atoms (for example, unsubstituted alkyl groups such as a methyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl and dodecyl group); substituted alkyl groups such as a benzyl and phenethyl group; and alkenyl groups of 2 to 20 carbon atoms (for example, unsubstituted alkenyl groups such as an oleyl, cetyl and allyl group).
[0053] Examples of the aryl group include phenyl, biphenyl and naphthyl; preferred is a phenyl group. The substitution may occur at any of the ortho-, para- and meta-position on the aryl group, and plural groups may be substituted. B and C, which may be the same or different, each represent:
(where a, b and c are each 0, 1, 2 or 3, d is 0 or 1 and Y is a hydrogen atom or a hydroxyl group).
m and n each represent an integer of 1 to 100.
X is a hydrogen atom or an alkyl, aralkyl or aryl group; examples thereof include those described with respect to A.
[0054] In formula [SII], M represents an alkali metal (e.g., Na, K, Li), a hydrogen atom or an ammonium or alkanolamine salt; n is an integer of 1 to 100; A represents a monovalent organic group, for example, an alkyl group having 6 to 20, preferably 6 to 12, carbon atoms such as a hexyl, heptyl, octyl, nonyl, decyl, undecyl or decyl group, or an aryl group substituted by an alkyl group of 3 to 20 carbon atoms: preferred substituents include an alkyl group of 3-12 carbon atoms such as a propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl or dodecyl group; examples of the aryl group includes a phenyl, tolyl, xynyl, biphenyl, and naphthyl group; preferred are a phenyl and tolyl group.
[0056] The following are examples of the compounds represented by formula [SI] or [SII], but suitable ones are not limited to them.
(Compounds represented by formula [SI])
[0057] Compounds SI-1 to SI-22: the same as compounds I-1 to 1-22 on pages 18-19 of Japanese Pat. Appl. No.178833/1990 Compounds SI-23
[0058]
Compounds SI-24 to SI-27: the same as compounds 1-24 to 1-27 on page 20 of Japanese Pat. Appl. No.178833/1990. Compounds SI-28
[0059]
Compounds SI-29 to SI-30: the same as compounds 1-29 to 1-30 on page 20 of japanese Pat. Appl. No.178833/1990. Compounds SI-31
[0063]
Compound SI-35: the same as compound 1-35 on page 21 of Japanese Pat. Appl. No.178833/1990 Compounds SI-36
[0065]
Compounds SI-38 to SI-46: the same as compounds 1-38 to 1-46 on pages 20-23 of Japanese Pat. Appl. No.178833/1990 Compounds SI-47
[0067] Compounds SI-48 to SI-78: the same as compounds 1-48 to 1-78 on pages 23-27 of Japanese Pat. Appl. No.178833/1990 (Compounds represented by formula [SII])
[0068] Compounds SII-1 to SII-7: the same as compounds V-1 to V-7 on pages 31-33 of Japanese Pat. Appl. No.178833/1990 Compounds SII-8
[0071] Among the above exemplified compounds, preferred are compounds SI-23, SI-28, SI-31, SI-32, SI-33, SI-34, SI-36, SI-37, SI-47, SII-8 and SII-9.
[0072] The compounds represented by formula [SI] or [SII] are used preferably in amount of 0.01 g/I to 2.0 g/I.
[0073] In a preferred embodiment of the invention, an optical whitening agent is contained in the color developer. Addition of an optical whitening agent not only improves the whiteness of unexposed portions of a light-sensitive material but also produces a good effect of preventing crystals from depositing.
[0074] Triazinylstilbene-type optical whitening agents are preferred in the invention; particularly preferred are those represented by the following formula [F].
[0075] The particulars of the compound represented by formula [F] are the same as those of the compound of formula [E] given on pages 73-75 of Japanese Pat. Appl. No.178833/1990.
[0076] Examples of the compounds represented by formula [F] Compounds F-1 to F-45: the same as compounds E-1 to E-45 on pages 76-82 of Japanese Pat. Appl. No.178833/1990.
[0077] These triazinylstilbene-type optical whitening agents can be synthesized according to the usual method described, for example, on page 8 of "Optical Whitening Agents" edited by KASEIHIN KOGYOKAI (issued in August, 1976).
[0078] Among the foregoing examples, compounds F-4, F-24, F-34, F-35, F-36, F-37 and F-41 are especially preferred.
[0079] The addition amount of the triazinylstilbene-type optical whitening agent is preferably 0.2 to 10 g, especially 0.4 to 5 g per liter of color developer.
[0080] Further, an auxiliary developing agent may also be used together with the developing agent. Such known auxiliary developing agents include N-methyl-p-aminophenol sulfate (Metol), phenidone, N,N'-diethyl- p-aminophenol hydrochloride, N,N,N',N'-tetramethyl-p-phenylenediamine hydrochloride; usually, these are employed in an amount of 0.01 to 1.0 g per liter.
[0081] In addition, there may also be used various additives such as antistain agents, sludge inhibitors and developing accelerators.
[0082] Moreover, it is preferable that a chelating agent represented by the following formula [K] be added to the color developer of the invention in order to attain the object of the invention effectively.
[0083] The particulars of the compound represented by formula [K] are the same as those of the compound of formula [K] described on pages 84-85 of Japanese Pat. Appl. No.178833/1990.
[0084] Examples of the compound represented by formula [K] Compounds K-1 to K-22: the same as compounds K-1 to K-22 on pages 85-89 of Japanese Pat. Appl. No.178833/1990.
[0085] In the invention, the color developer can be used within any reasonable pH range. But, in view of rapid processing, it is used preferably within a pH range of 9.5 to 13.0, especially within a pH range of 9.8 to 12.0. The processing temperature is generally not lower than 30 °C, preferably not lower than 33 ° C and especially 35 ° C to 65 ° C. The processing time is usually not less than 90 sec, preferably 3 sec to 60 sec and especially 3 sec to 45 sec.
[0086] In embodying the invention, the intended effect of the invention is brought out much better as the replenishing rate decreases; accordingly, the replenishing rate of the color developer is not more than 120 ml/m2, preferable not more than 110 ml/m2 and especially not more than 100 ml/m2.
[0088] The color developer of the invention can be applied to any light-sensitive material as long as those light-sensitive materials are for the so-called coupler-in-emulsion process which contain couplers in themselves; examples thereof are color paper, color negative films, color positive films, color reversal films for slides, color reversal films for movies, color reversal films for TVs and color reversal paper; but silver chloride rich color paper is particularly preferred.
EXAMPLES
[0089] The present invention is hereinafter described in detail with examples, but the embodiment of the invention is not limited to them.
Example 1
[Color Developer (1)]
[0092] Water was added to 1 liter, and the pH was adjusted to 10.60 with potassium hydroxide or sulfuric acid.
(Experiment 1)
[0094] A multilayer color light-sensitive material was prepared by forming the layers respectively having the following compositions on a paper support laminated with polyethylene on one side and with a titanium- oxide-containing polyethylene on the other side to bear the above layers. The coating solutions used were prepared as follows:
Coating Solution for 1 st Layer
[0095] There were dissolved 26.7 g of yellow coupler (Y-1), 10.0 g of dye image stabilizer (ST-1), 6.67 g of dye image stabilizer (ST-2) and 0.67 g of additive (HQ-1) in 6.67 g of high boiling solvent and 60 ml of ethyl acetate. Then, the solution was emulsified and dispersed with a supersonic homogenizer in 220 ml of 10% aqueous solution of gelatin containing 7 ml of 20% aqueous solution of surfactant (SU-1) to obtain a yellow coupler dispersion.
[0096] The dispersion was mixed with a blue-sensitive silver halide emulsion (containing 10 g of silver), so that a coating solution for the 1 st layer was prepared.
[0098] As hardeners, hardener (H-1) was added to the 2nd and 4th layer, and hardener (H-2) to the 7th layer. Further, surfactants (SU-2) and (SU-3) were added as coating aids to adjust the surface tension.
[0100] DOP: Dioctyl phthalate, DNP: Dinonyl phthalate DIDP: Diisodecyl phthalate, PVP: Polyvinylpyrrolidone
(Preparation of Blue-sensitive Silver Halide Emulsion)
[0101] The following solutions (A) and (B) were simultaneously added over a period of 30 minutes to 1000 ml of 2% aqueous solution of gelatin kept at 40 °C, while controlling the pAg at 6.5 and the pH at 3.0. Subsequently, the following solutions (C) and (D) were simultaneously added thereto over a period of 180 minutes, with the pAg and pH controlled at 7.3 and 5.5, respectively.
[0102] The control of the pAg was carried out according to the method described in Japanese Pat. O.P.I. Pub. No. 45437/1984, and that of the pH was made by use of sulfuric acid and an aqueous solution of sodium hydroxide.
[0103] After the addition, the resultant silver halide was subjected to desalting using 5% aqueous solution of Demol N (product of Kao Atlas Inc.) and 20% aqueous solution of magnesium sulfate and then mixed with an aqueous solution of gelatin. Emulsion EPM-1 thus obtained comprised monodispersed cubic grains having an average size of 0.85 am, a coefficient of variation (a/r) of 0.07 and a silver chloride content of 99.5 mol%.
[0104] Emulsion EMP-1 was chemically ripened at 50 °C for 90 minutes using the following compounds to obtain a blue-sensitive silver halide emulsion, Em-B.
(Preparation of Green-sensitive Silver Halide Emulsion)
[0105] Emulsion EMP-2 was prepared in the same manner as EMP-1 except that the addition time of solutions (A) and (B) as well as that of solutions (C) and (D) were changed. The emulsion comprised monodispersed cubic grains having an average size of 0.43 µm, a coefficient of variation (a/r) of 0.08 and a silver chloride content of 99.5 mol%.
[0106] Then, emulsion EMP-2 was chemically ripened at 55 °C for 120 minutes using the following compounds to obtain a green-sensitive silver halide emulsion, Em-G.
(Preparation of Red-sensitive Silver Halide Emulsion)
[0107] Emulsion EMP-3 was prepared in the same manner as EMP-1 except that the addition time of solutions (A) and (B) as well as that of solutions (C) and (D) were changed. The emulsion comprised monodispersed cubic grains having an average size of 0.50 µm, a coefficient of variation (a/r) of 0.08 and a silver chloride content of 99.5 mol%.
[0108] Then, emulsion EMP-3 was chemically ripened at 60 °C for 90 minutes using the following compounds to obtain a red-sensitive silver halide emulsion, Em-R.
[0109] The color paper sample was exposed in the usual manner and then processed by use of the following processes and processing solutions.
(Color Developing Tank Solution)
[0111] Water was added to 1 liter, and the pH was adjusted to 10.60 with potassium hydroxide or sulfuric acid.
(Color Developing Replenisher)
(Bleach-fixing Tank Solution and Replenisher)
[0114] The pH was adjusted to 6.5 with an aqueous ammonia or glacial acetic acid, and water was added to 1 liter.
(Stabilizing Tank Solution and Replenisher)
[0116] The pH was adjusted to 7.8 with an aqueous ammonia or sulfuric acid, and water was added to 1 liter.
[0117] Continuous processing was run using the color paper and the processing solutions prepared as above.
[0118] After filling an automatic processor with the above color developing tank solution, bleach-fixing tank solution and stabilizing tank solution, the color paper was continuously processed, with the above auxiliary color developer, bleach-fixing replenisher and stabilizing replenisher fed through metering pumps at intervals of 3 minutes.
[0119] The continuous processing was carried on, at a rate of 0.03 R per day, till the volume of the color developer replenished in the color developing tank reached three times the capacity of the tank. Here, 1 R means the auxiliary color developer is replenished up to a volume equal to the capacity of the color developing tank.
[0120] After the continuous processing, fluctuations in color forming property and fogging were examined.
[0121] The color forming property was examined by measuring a maximum yellow density (Y-Dmax), and the fogging was examined by measuring a reflective yellow density (Y-Dmin) of unexposed portion.
[0122] Further, the gear and rack in the color developing tank were inspected for deposition using the following criteria:
A: absolutely no deposition.
B: slight depositions on the wall.
C: many caked depositions on the rack.
D: many caked depositions on the rack and gear.
(Experiment 2)
[0123] Color developer (1) was put into the replenishing tank of the automatic processor and stored for 2 months at 0 ° C. During storing, the replenishing pump was run intermittently for 10 minutes every day to discharge 1% of the total replenisher volume. After 2 months, the residual amount of color developing agent in the replenisher left on the bottom of the tank was determined and, at the same time, the degree of deposition in the replenishing pump was evaluated according to the following criteria:
A: absolutely no deposition.
B: trace amounts of floating matters.
C: small amounts of black depositions.
D: large amounts of black, caked depositions.
[0125] As is seen in Table 2, it is confirmed that a stable maintenance of color forming property, an excellent whiteness in a color print, and an effective prevention of depositions in a tank and replenishing pump can be achieved, even in processing with low replenishment, only when the combination specified by the invention is used.
Example 2
[0126] The same experiment as color developer No.17 of Example 1 was made, except that the addition amount of compound 1-17 was varied as shown in Table 3.
[0127] It can be understood from Table 3 that the addition amount of additive (1) is preferably 2.0 to 100 g/I, especially 5.0 to 50 g/I.
Example 3
[0128] An experiment was conducted using compounds 2-2, 2-4, 2-25 and 2-29 by turns instead of additive 1-17 in color developer No.17 of Example 1, in varied amounts shown in Example 2. Though a few percent reduction was observed in the residual amount of color developing agent, the intended effect of invention was clearly brought out.
Example 4
[0129] The same procedure as Example 1 was repeated except that the following processes were used in place of the processes employed in Example 1. The results were much the same as those in Example 1.
[0130] In color developer No.17 of Example 1, both Uvitex MST and Tinopal SFP were replaced with compounds F-36 and F-36, optical whitening agents represented by formula [F]. Then, continuous processing was run as Experiment 1 of Example 1 at a daily processing rate of 0.02 R; and Experiment 2 was also conducted as in Example 1, except that the storing period was changed to 3 months. The results are shown in Table 4.
[0131] It can be seen in Table 4 that addition of triazinylstilbene-type optical whitening agents produces favorable results in the embodiment of the invention.
Example 5
[0132] Continuous processing was run as with color developer No.17 of Example 1 using preservatives shown in Table 5 in place of N,N-diethylhydroxylamine; in Experiment 1 of Example 1 , the daily processing rate was 0.02 R; in Experiment 2, the storing period was 3 months. The results are shown in Table 5.
[0133] It can be seen in Table 5 that use of the compound represented by formula [A] or [B] as a preservative brings about favorable results.
Example 6
1. A color developer for a silver halide color photographic light-sensitive material
comprising at least one compound represented by Formula 1, and a color developing
agent in an amount not less than 0.02 mol/I, and a compound selected from the group
consisting of an aromatic sulfonic acid and an aromatic compound having a -O-S03-R group in an amount not less than 2.5 mol per mol of a color developing agent:
wherein R represents a hydrogen atom, a sodium atom, a potassium atom, an ammonium
group or an lithium atom:
wherein A and B each represent a linear or branched alkylene group, n and m each represent an integer of 0 to 100, provided that both A and B are not 0, and A or B is a linear or branched alkylene group having 3 or more carbon atoms when n + m = 1.
2. The color developer of claim 1, wherein said aromatic sulfonic acid is represented
by Formula 2 or Formula 3:
wherein A to F each represent a hydrogen atom or an alkyl group, and at least one of A to F is a sulfonic acid; G to N each represent a hydrogen atom or an alkyl group, and at least one of G to N is a sulfonic acid.
wherein A to F each represent a hydrogen atom or an alkyl group, and at least one of A to F is a sulfonic acid; G to N each represent a hydrogen atom or an alkyl group, and at least one of G to N is a sulfonic acid.
3. The color developer of claim 1, wherein said aromatic compound having -O-S03-R group is represented by Formula 2 or Formula 3:
wherein A to F each represent a hydrogen atom or an alkyl group, and at least one of A to F is a -O-S03-R group; G to N each represent a hydrogen atom or an alkyl group, and at least one of G to N is a -0-S03-R group: R represents a hydrogen atom, a sodium atom, a potassium atom, an ammonium group or an lithium atom.
wherein A to F each represent a hydrogen atom or an alkyl group, and at least one of A to F is a -O-S03-R group; G to N each represent a hydrogen atom or an alkyl group, and at least one of G to N is a -0-S03-R group: R represents a hydrogen atom, a sodium atom, a potassium atom, an ammonium group or an lithium atom.
4. The color developer of claim 1, 2 or 3, wherein the amount of said compound represented
by Formula 1 is within the range of 2.0 to 100 g/I.
5. The color developer of claim 1, 2, 3 or 4, wherein said compound represented by
Formula 1 is a compound selected from the group consisting of 1-10, 1-17 and 1-26.
6. A color developer for a silver halide color photographic light-sensitive material
comprising at least one compound represented by Formula 1, and a color developing
agent in an amount not less than 0.02 mol/I, and a compound selected from the group
consisting of an aromatic sulfonic acid and an aromatic compound having a -0-S03-R group in an amount not less than 2.5 mol per mol of a color developing agent:
wherein A to F each represent a hydrogen atom or an alkyl group, and at least one of A to F is a -O-S03-R group; G to N each represent a hydrogen atom or an alkyl group, and at least one of G to N is a -O-SO3-R group.
wherein the amount of said compound represented by Formula 1 is within the range of
2.0 to 100 g/I, R represents a hydrogen atom, a sodium atom, a potassium atom, an
ammonium group or an lithium atom:
wherein A and B each represent a linear or branched alkylene group, n and m each represent an integer of 0 to 100, provided that both A and B are not 0, and A or B is a linear or branched alkylene group having 3 or more carbon atoms when n + m = 1:
said aromatic sulfonic acid is represented by Formula 2 or Formula 3:
wherein A to F each represent a hydrogen atom or an alkyl group, and at least one of A to F is a sulfonic acid; G to N each represent a hydrogen atom or an alkyl group, and at least one of G to N is a sulfonic acid:
said aromatic compound having -O-SO-R group is represented by Formula 2 or Formula 3:
wherein A to F each represent a hydrogen atom or an alkyl group, and at least one of A to F is a -O-S03-R group; G to N each represent a hydrogen atom or an alkyl group, and at least one of G to N is a -O-SO3-R group.