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Description  |
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FIELD OF THE INVENTION
The present invention relates to a method for processing a silver halide
color photographic material (hereinafter referred to simply as a color
light-sensitive material), and more particularly, to a method for color
development processing of a color light-sensitive material containing
silver iodide using a low level of replenishment which provides stable
photographic properties and excellent image quality.
BACKGROUND OF THE INVENTION
In recent years, a method for processing a silver halide color
light-sensitive material using a reduced amount of replenishment for the
development processing step has been highly desired from the standpoint of
simplification of the processing method and prevention of environmental
pollution.
The amount of replenishment for continuous color development processing
varies depending on the type of color light-sensitive material, and is
generally from 700 to 1300 ml per square meter of a color light-sensitive
material for photographing being processed.
When the amount of replenishment is reduced, problems generally arise in
that photographic performance varies due to the relative increase in the
amount of components (for example, halide ions formed upon decomposition
of silver halide) contained in the color developing solution which are
released from the color light-sensitive material, solution, and in that
staining is generated after processing and the photographic performance is
changed by deterioration of the color developing solution which is caused
by the increase in the retention time of the solution in the processing
tank.
In order to solve the former problems of variation in photographic
performance such as sensitivity and gradation and particularly the
deterioration of granularity at a low exposed area, upon the continuous
processing, a method has been proposed for preventing the decrease in
sensitivity, stabilizing gradation and minimum density by increasing the
processing temperature or pH. However, the attempt to compensate the
variation in photographic performance due to halide ion by adjusting the
processing temperature or pH generally results in degradation of color
balance and an increase in staining.
With respect to the latter problem of deterioration of the color developing
solution upon oxidation, the use of hydroxylamine derivatives substituted
with an alkyl group have been proposed as disclosed, for example, in U.S.
Pat. No. 4,810,516, JP-A-63-4234 and JP-A-63-106655 (the term "JP-A" as
used herein means an "unexamined published Japanese patent application"),
in order to increase the stability of the color developing solution. Some
of these compounds exhibit a certain degree of preservability in a low
level replenishment system for a color developing solution, and do not
adversely affect photographic performance and do not stain high silver
chloride content type color light-sensitive materials. However, it has
been found that the above noted compounds are not effective when
processing color light-sensitive materials comprising a silver halide
containing silver iodide. Furthermore, other problems occur in that the
variation of photographic properties such as minimum density (D.sub.min),
sensitivity, granularity and gradation and staining in the uncolored
portions is increased. These problems are particularly pronounced in a low
level replenishment system.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a method for continuously
processing a color light-sensitive material containing silver iodide in a
color developing solution having improved stability and which provides
stable photographic performance.
A second object of the present invention is to provide a method for
processing a color light-sensitive material in which the above described
object is still attained even when the amount of replenishment for the
color developing solution is reduced.
Other objects of the present invention will become apparent from the
following description and examples.
The above objects of the present invention are accomplished with a method
for processing a silver halide color photographic material which comprises
processing an imagewise exposed silver halide color photographic material
comprising a support having thereon at least one silver halide emulsion
layer containing silver halide having a silver iodide content of at least
2 mol % with a color developing solution, wherein said color developing
solution contains at least one compound represented by formula (I),
bromide ion in an amount of from 1.0.times.10.sup.-2 to
5.0.times.10.sup.-1 mol per liter and iodide ion in an amount of not more
than 1.0.times.10.sup.-4 mol per liter:
##STR2##
wherein L represents an alkylene group; A represents a carboxy group, a
sulfo group, a phosphono group, a phosphinic acid residual group, a
hydroxy group, an unsubstituted amino group or an amino group which is
substituted with an alkyl group, an unsubstituted ammonio group or an
ammonio group which is substituted with an alkyl group, an unsubstituted
carbamoyl group or a carbamoyl group which is substituted with an alkyl
group, an unsubstituted sulfamoyl group or a sulfamoyl group which is
substituted with an alkyl group, or an alkylsulfonyl group; and R
represents a hydrogen atom or an alkyl group.
DETAILED DESCRIPTION OF THE INVENTION
The compound represented by formula (I) is described in detail below.
In formula (I), L preferably represents a straight chain or branched chain
alkylene group having from 1 to 10 carbon atoms, more preferably from 1 to
5 carbon atoms, which may be substituted. Preferred examples of the
alkylene group represented by L include methylene, ethylene, trimethylene,
and propylene. Useful substituents for L include a carboxy group, a sulfo
group, a phosphono group, a phosphinic acid residual group, a hydroxy
group, and an unsubstituted ammonio group or an ammonio group which is
substituted with an alkyl group. Among them, a carboxy group, a sulfo
group, a phosphono group and a hydroxy group are preferred as the
substituents.
In formula (I), A represents a carboxy group, a sulfo group, a phosphono
group, a phosphinic acid group, a hydroxy group, an unsubstituted amino
group or an amino group which is substituted with an alkyl group, an
unsubstituted ammonio group or an ammonio group which is substituted with
an alkyl group, an unsubstituted carbamoyl group or a carbamoyl group
which is substituted with an alkyl group, an unsubstituted sulfamoyl group
or a sulfamoyl group which is substituted with an alkyl group, or an
alkylsulfonyl group which may be substituted with substituents for L, and
preferably represents a carboxy group, a sulfo group, a hydroxy group, a
phosphono group, an unsubstituted carbamoyl group or a carbamoyl group
which is substituted with an alkyl group.
Preferred examples of -L-A include carboxymethyl, carboxyethyl,
carboxypropyl, sulfoethyl, sulfopropyl, sulfobutyl, phosphonomethyl,
phosphonoethyl, and hydroxyethyl. Among them, carboxymethyl, carboxyethyl,
sulfoethyl, sulfopropyl, phosphonomethyl, and phosphonoethyl are
particularly preferred.
In formula (I), R preferably represents a hydrogen atom or a straight chain
or branched chain alkyl group having from 1 to 10 carbon atoms, more
preferably from 1 to 5 carbon atoms, which may be substituted. Useful
substituents include a carboxy group, a sulfo group, a phosphono group, a
phosphinic acid residual group, a hydroxy group, an unsubstituted amino
group or an amino group which is substituted with an alkyl group, an
unsubstituted ammonio group or an ammonio group which is substituted with
an alkyl group, an unsubstituted carbamoyl group or a carbamoyl group
which is substituted with an alkyl group, an unsubstituted sulfamoyl group
or a sulfamoyl group which is substituted with an alkyl group, or an
alkylsulfonyl group which may be substituted with substituents for L, an
acylamino group, an alkylsulfonylamino group, an arylsulfonylamino group,
an alkoxycarbonyl group, an arylsulfonyl group, a nitro group, a cyano
group, and a halogen atom. The group R may have two or more substituents.
Preferred examples of R include hydrogen, carboxymethyl, carboxyethyl,
carboxypropyl, sulfoethyl, sulfopropyl, sulfobutyl, phosphonomethyl,
phosphonoethyl, and hydroxyethyl. Among them, hydrogen, carboxymethyl,
carboxyethyl, sulfoethyl, sulfopropyl, phosphonomethyl, and phosphonoethyl
are particularly preferred.
In formula (I), A or the substituents for R may be a salt of alkali metals
such as sodium and potassium. L and R may combine together to form a ring.
Specific examples of the compounds represented by formula (I) are set forth
below, but the present invention is not to be construed as being limited
thereto.
##STR3##
The compounds represented by formula (I) can be synthesized by alkylation
(nucleophilic replacement reaction, addition reaction or Mannich reaction)
of a commercially available hydroxylamine. Particularly, the compounds
represented by formula (I) can be synthesized according to synthesis
methods as described, for example, in West German Patent 1,159,634 and
Inorganica Chimica Acta, Vol. 93, pages 101 to 108 (1984). Specific
examples of synthesis of the compound represented by formula (I) are
provided below.
SYNTHESIS EXAMPLE 1
Synthesis of Compound (7)
To 200 ml of an aqueous solution containing 20 g of hydroxylamine
hydrochloride were added 11.5 g of sodium hydroxide and 96 g of sodium
chloroethanesulfonate. The mixture was maintained at 60.degree. C., and 40
ml of an aqueous solution containing 23 g of sodium hydroxide was
gradually added thereto over a period of 1 hour, followed by reaction at
60.degree. C. for 3 hours. The reaction solution was concentrated under
reduced pressure, and to the resulting residue was added 200 ml of
concentrated hydrochloric acid, followed by heating at 50.degree. C. After
removing the insoluble components by filtration, to the filtrate was added
500 ml of methanol to obtain 41 g (yield: 53%) of the Compound (7) as a
monosodium salt.
SYNTHESIS EXAMPLE 2
Synthesis of Compound (11)
To an aqueous hydrochloric acid solution containing 7.2 g of hydroxylamine
hydrochloride and 18.0 g of phosphorous acid was added 32.6 g of formalin,
and the mixture was refluxed by heating for 2 hours. The crystals thus
formed were recrystallized from water and methanol to obtain 9.2 g (yield:
42%) of Compound (11).
The color developing solution contains a compound represented by formula
(I) in an amount of preferably from 0.1 to 50 g, more preferably from 0.2
to 20 g, per liter of the color developing solution.
The compound of formula (I) may be added to the color light-sensitive
material and released to (i.e., eluted into) the color developing solution
upon processing in the amount described above.
The compound of formula (I) effectively act as a preservative for the color
developing agent when employed in the amount described above. Furthermore,
the compound of formula (I) can also be present in a bleaching solution, a
bleach-fixing solution, washing water or a stabilizing solution to be used
instead of washing water. In the latter case, the compound of formula (I)
is effective with respect to the color developing agent or oxidation
product thereof carried over from the color developing solution present in
each the above processing solution, to provide good results.
Two or more compounds of formula (I) may be used in combination, and the
mixing ratio thereof is appropriately selected.
Furthermore, the compound represented by formula (I) can be used together
with a known preservative, for example, a sulfite, a bisulfite, a
hydroxamic acid, a hydrazine, a hydrazide, a phenol, an
.alpha.-hydroxyketone, .alpha.-aminoketone, a saccharide, a monoamine, a
diamine, a polyamine, a quaternary ammonium salt, a nitroxy radical, an
alcohol, an oxime, a diamide compound, and a condensed cyclic amine.
The color developing solution of the present invention, preferably also
contains, a compound represented by formula (II) in order to enhance the
effects of the present invention:
##STR4##
wherein R.sub.11 represents a hydroxyalkyl group having from 2 to 6 carbon
atoms, and R.sub.12 and R.sub.13 each represents a hydrogen atom, an
unsubstituted alkyl group having from 1 to 6 carbon atoms, a hydroxyalkyl
group having from 2 to 6 carbon atoms, a benzyl group or the group
##STR5##
(wherein n represents an integer of from 1 to 6; X and X' each represents
a hydrogen atom, an unsubstituted alkyl group having from 1 to 6 carbon
atoms or a hydroxyalkyl group having from 2 to 6 carbon atoms).
Preferred examples of the compound represented by formula (II) are set
forth below, but the present invention is not to be construed as being
limited thereto.
(II-1) Ethanolamine
(II-2) Diethanolamine
(II-3) Triethanolamine
(II-4) Diisopropanolamine
(II-5) 2-Methylaminoethanol
(II-6) 2-Ethylaminoethanol
(II-7) 2-Dimethylaminoethanol
(II-8) 2-Diethylaminoethanol
(II-9) 1-Diethylamino-2-propanol
(II-10) 3-Diethylamino-1-propanol
(II-11) 3-Dimethylamino-1-Propanol
(II-12) Isopropylaminoethanol
(II-13) 3-Amino-1-propanol
(II-14) 2-Amino-2-methyl-1,3-propanediol
(II-15) Ethylenediaminetetraisopropanol
(II-16) Benzylethanolamine
(II-17) 2-Amino-2-(hydroxymethyl)-1,3-propanediol
(II-18) 1,3-Diaminopropanol
(II-19) 1,3-Bis(2-hydroxyethylmethylamino)propanol
Of the above described compounds, (II-1), (II-2), and (II-3) are most
preferred.
The color developing solution contains a compound represented by formula
(II) in an amount of preferably from 3 to 100 g, more preferably from 6 to
50 g per liter of the color developing solution of the present invention.
The color developing solution of the present invention further preferably
contains a compound represented by formula (B-I) or (B-II) in order to
enhance the effects of the present invention:
##STR6##
wherein R.sub.14, R.sub.15, R.sub.16 and R.sub.17 each represents a
hydrogen atom, a halogen atom, a sulfonic acid group, an alkyl group
having from 1 to 7 carbon atoms, --OR.sub.18, --COOR.sub.19,
##STR7##
or a phenyl group; and R.sub.18, R.sub.19, R.sub.20 and R.sub.21 ; each
represents a hydrogen atom or an alkyl group having from 1 to 18 carbon
atoms, provided that when R.sub.15 represents --OH or a hydrogen atom,
R.sub.14 represents a halogen atom, a sulfonic acid group, an alkyl group
having from 1 to 7 alkyl group, --OR.sup.18 --COOR.sup.19,
##STR8##
or a phenyl group.
The alkyl group represented by R.sub.14, R.sub.15, R.sub.16 or R.sub.17
includes an alkyl group which may be substituted with substituents for L.
Useful examples of the alkyl group include methyl, ethyl, isopropyl,
n-propyl, tert-butyl, n-butyl, hydroxymethyl, hydroxyethyl, carboxymethyl,
and benzyl The alkyl group represented by R.sub.18, R.sub.19, R.sub.20 or
R.sub.21 has the same meaning as above and further includes octyl. Useful
examples of the phenyl group represented by R.sub.14, R.sub.15, R.sub.16
and R.sub.17 include phenyl, 2-hydroxyphenyl, and 4-aminophenyl.
Representative examples of the chelating agent represented by formulae
(B-I) and (B-II) are provided below, but the present invention is not to
be construed as being limited thereto.
(B-I-1) 4-Isopropyl-1,2-dihydroxybenzene
(B-I-2) 1,2-Dihydroxybenzene-3,5-disulfonic acid
(B-I-3) 1,2,3-Trihydroxybenzene-5-carboxylic acid
(B-I-4) 1,2,3-Trihydroxybenzene-5-carboxymethyl ester
(B-I-5) 1,2,3-Trihydroxybenzene-5-carboxy-n-butyl ester
(B-I-6) 5-tert-Butyl-1,2,3-trihydroxybenzene
(B-I-7) 1,2-Dihydroxybenzene-3,4,6-trisulfonic acid
(B-II-1) 2,3-Dihydroxynaphthalene-6-sulfonic acid
(B-II-2) 2,3,8-Trihydroxynaphthalene-6-sulfonic acid
(B-II-3) 2,3-Dihydroxynaphthalene-6-carboxylic acid
(B-II-4) 2,3-Dihydroxy-8-isopropylnaphthalene
(B-II-5) 2,3-Dihydroxy-8-chloronaphthalene-6-sulfonic acid
Of the above described compounds, 1,2-dihydroxybenzene-3,5-disulfonic acid
(B-I-2) is particularly preferably employed in the present invention. This
compound is also employed as an alkali metal salt such as a sodium salt or
a potassium salt.
The compound represented by formula (B-I) or (B-II) described above is
employed generally in an amount of from 5 mg to 15 g, preferably from 15
mg to 10 g, and more preferably from 25 mg to 7 g, per liter of the color
developing solution of the present invention.
The color developing solution of the present invention contains bromide ion
in an amount of from 1.0.times.10.sup.-2 to 5.0.times.10.sup.-1 mol per
liter and iodide ion in an amount of not more than 1.0.times.10.sup.-4 mol
per liter as halide ion.
The present inventors have discovered that the variation of photographic
performance such as D.sub.min, the increase in staining after processing
and particularly, granularity at a low exposed area are remarkably
improved when a color light-sensitive material containing silver iodide is
processed with the color developing solution of the present invention
having the above noted bromide ion concentration and iodide ion
concentration, and containing the compound represented by formula (I).
These results are unexpected.
The photographic performance of a color light-sensitive material generally
changes with a change in the bromide ion concentration and iodide ion
concentration in the color developing solution. As the halide ion
concentration in the color developing solution is increased, development
is generally restrained, and D.sub.min as well as maximum density
(D.sub.max) decrease, resulting in soft gradation and decreasing
sensitivity. On the other hand, as the halide ion concentration is
decreased, D.sub.max reaches the maximum density corresponding to
characteristics of coupler used, D.sub.min greatly increases, and
gradation and sensitivity vary as D.sub.min changes. Of the halide ions,
the iodide ion concentration imparts particularly large effects.
Further, the decrease in activity of the color developing solution due to
the low replenishment rate processing easily influences the granularity of
images and particularly the granularity at the low exposed area is easily
deteriorated.
On the other hand, it is quite surprising that the above described
exceptional effects of the present invention are obtained by the combined
use of bromide ion in a concentration of from 1.0.times.10.sup.-2 to
5.0.times.10.sup.-1 mol per liter and an iodide ion in a concentration of
not more than 1.0.times.10.sup.-4 mol per liter and the compound
represented by formula (I) in the color developing solution in accordance
with the method of the present invention.
In order to maintain the halide ion concentration in the above described
range, halide ion can be directly added to the color developing solution
or may be released from (i.e., eluted from) the light-sensitive material
during processing. In the case of directly adding halide ion to the color
developing solution, any inorganic compound or organic compound which
releases halide ion can be used, but an inorganic compound is generally
employed.
Useful examples of compounds which supply bromide ion include an alkali
metal bromide (e.g., sodium bromide, potassium bromide, and lithium
bromide), an alkaline earth metal bromide (e.g., magnesium bromide and
calcium bromide), a transition metal bromide (e.g., manganese bromide,
nickel bromide, and cobalt bromide), and ammonium bromide. Of these
compounds, potassium bromide and sodium bromide are preferred.
Useful examples of the compounds which supply iodide ion include potassium
iodide, and ammonium iodide.
When the halide ion is supplied and released from the light-sensitive
material during processing, the halide ion may be derived from a silver
halide emulsion or from other additives contained in the light-sensitive
material.
In the present invention, the bromide ion concentration is preferably from
1.5.times.10.sup.-2 to 2.times.10.sup.-1 mol per liter, more preferably
from 2.5.times.10.sup.-2 to 1.times.10.sup.-1 mol per liter, and the
iodide ion concentration is preferably from 1.times.10.sup.-7 to
1.0.times.10.sup.-2 mol per liter, more preferably from
5.0.times.10.sup.-7 to 5.0.times.10.sup.-5 mol per liter, most preferably
from 5.0.times.10.sup.-7 to 1.0.times.10.sup.-5 mol per liter of the color
developing solution.
In accordance with the method of the present invention, the amount of
replenishment for the color developing solution is preferably not more
than 700 ml more preferably from 100 to 600 ml, and particularly
preferably from 200 to 500 ml, per square meter of the color
light-sensitive material being processed.
The color developing solution for use in the present invention contains a
known aromatic primary amine color developing agent. Preferred examples
thereof are p-phenylenediamine derivatives. Useful examples of the
p-phenylenediamine derivative are set forth below, but the present
invention is not to be construed as being limited thereto.
D-1: N,N-Diethyl-p-phenylenediamine
D-2: 2-Amino-5-diethylaminotoluene
D-3: 2-Amino-5-(N-ethyl-N-laurylamino)toluene
D-4: 4-[N-Ethyl-N-(8-hydroxyethyl)amino]aniline
D-5: 2-Methyl-4-[N-ethyl-N-(8-hydroxyethyl)amino]aniline
D-6: 4-Amino-3-methyl-N-ethyl-N-[8-(methanesulfonamido)ethyl]aniline
D-7: N-(2-Amino-5-diethylaminophenylethyl)methanesulfonamide
D-8: N,N-Dimethyl-p-phenylenediamine
D-9: 4-Amino-3-methyl-N-ethyl-N-methoxyethylaniline
D-10: 4-Amino-3-methyl-N-ethyl-N-.beta.-ethoxyethylaniline
D-11 4-Amino-3-methyl-N-ethyl-N-.beta.-butoxyethylaniline
Of these p-phenylenediamine derivatives described above,
2-methyl-4-[N-ethyl-N-(.beta.-hydroxyethyl)amino]aniline (D-5) and
4-amino-3-methyl-N-ethyl-N-[.beta.-(methanesulfonamido)ethyl]aniline (D-6)
are particularly preferred.
The p-phenylenediamine derivatives may be in the form of salt such as a
sulfate, hydrochloride, sulfite, or p-toluenesulfonate.
The aromatic primary amine developing agent is used preferably in an amount
of from about 0.1 to about 20 g, more preferably from about 0.5 to about
15 g per liter of the developing solution.
The color developing solution for use in the present invention preferably
has a pH of from 9 to 12 and more preferably from 9 to 11.0. The color
developing solution may also contain compounds that are known additives of
a developing solution.
In order to maintain the pH of the color developing solution in the
above-described range, various buffers are preferably employed. Specific
examples of these buffers include sodium carbonate, potassium carbonate,
sodium bicarbonate, potassium bicarbonate, trisodium phosphate,
tripotassium phosphate, disodium phosphate, dipotassium phosphate, sodium
borate, potassium borate, sodium tetraborate (borax), potassium
tetraborate, sodium o-hydroxybenzoate (sodium salicylate), potassium
o-hydroxybenzoate, sodium 5-sulfo-2-hydroxybenzoate (sodium
5-sulfosalicylate), and potassium 5-sulfo-2-hydroxybenzoate (potassium
5-sulfosalicylate). The amount of the buffer added to the color developing
solution is preferably 0.1 mol or more and particularly preferably from
0.1 to 0.4 mol per liter of the color developing solution.
In addition, various chelating agents can be added to the color developing
solution in accordance with the present invention for the purpose of
preventing calcium or magnesium precipitation, or for improving the
stability of the color developing solution.
Specific examples of the chelating agents for use in the color developing
solution of the present invention are set forth below, but the present
invention is not to be construed as being limited thereto.
Nitrilotriacetic acid
Diethyleneaminopentaacetic acid
Ethylenediaminetetraacetic acid
Triethylenetetraminehexaacetic acid
Nitrilo-N,N,N-trismethylenephosphonic acid
Ethylenediamine-N,N,N',N'-tetrakismethylenephosphonoic acid
1,3-Diamino-2-propanoltetraacetic acid
Trans-cyclohexanediaminetetraacetic acid
Nitrilotripropionic acid
1,2-Diaminopropanetetraacetic acid
Hydroxyethyliminodiacetic acid
Glycol ether diaminetetraacetic acid
Hydroxyethylenediaminetriacetic acid
Ethylenediamine-o-hydroxyphenylacetic acid
2-Phosphonobutane-1,2,4-tricarboxylic acid
1-Hydroxyethylidene-1,1-diphosphonic acid
N,N'-Bis(2-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid
Catechol-3,4,6-trisulfonic acid
Catechol-3,5-disulfonic acid
5-Sulfosalicylic acid
4-Sulfosalicylic acid
Of these chelating agents, ethylenediaminetetraacetic acid,
ethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid,
1,3-diaminopropanoltetraacetic acid,
ethylenediamine-N,N,N',N'-tetrakismethyleneposphonic acid, and
hydroxyethyliminodiacetic acid are preferred.
Two or more chelating agents may be employed together, if desired.
The chelating agent is added to the color developing solution in an amount
sufficient to mask metal ions contained therein. For example, the
chelating agent is added to the color developing solution in an amount of
from about 0.1 to about 10 g per liter.
The color developing solution of the present invention may contain a
development accelerator, if desired.
Examples of useful development accelerators include thioether type
compounds as described in JP-B-37-16088, JP-B-37-5987, JP-B-38-7826,
JP-B-44-12380, JP-B-45-9019 and U.S. Pat. No. 3,813,247;
p-phenylenediamine type compounds as described in JP-A-52-49829 and
JP-A-50-15554; quaternary ammonium salts as described in JP-A-50-137726,
JP-B-44-30074, JP-A-56-156826 and JP-A-52-43429; amine type compounds as
described in U.S. Pat. Nos. 2,494,903, 3,128,182, 4,230,796, 3,253,919,
2,482,546, 2,596,926, and 3,582,346 and JP-B-41-11431; polyalkylene oxides
as described in JP-B-37-16088, JP-B-42-25201, JP-B-41-11431,
JP-B-42-23883 and U.S. Pat. Nos. 3,128,183 and 3,532,501;
1-phenyl-3-pyrazolidones; and imidazoles.
The color developing solution of the present invention preferably does not
substantially contain benzyl alcohol. The term "substantially not contain
benzyl alcohol" means that the color developing solution contains benzyl
alcohol in an amount not more than 2.0 ml per liter of the solution, and
preferably contains no benzyl alcohol. The color developing solution of
the present invention which substantially does not contain benzyl alcohol
provides preferred results with respect to the variation of photographic
performance, and particularly, the increase in staining is reduced as the
continuous processing proceeds.
The color developing solution of the present invention may contain
antifoggants, if desired, in addition to iodide ion and bromide ion. An
organic antifoggant may be employed. Representative examples of useful
organic antifoggants include nitrogen-containing heterocyclic compounds
such as benzotriaxole, 6-nitrobenzimidazole, 5-nitroisoindazole,
5-methylbenzotriazole, 5-nitrobenzotriazole, 5-chlorobenzotriazole,
2-thiazolylbenzimidazole, 2-thiazolylmethylbenzimidazole, indazole,
hydroxyazaindolizine, and adenine.
The color developing solution of the present invention may contain a
sulfite such as sodium sulfite, potassium sulfite, sodium bisulfite,
potassium bisulfite, sodium metabisulfite and potassium metabisulfite, and
an adduct of carbonyl sulfinic acid. An amount of these compounds added is
preferably from 0.5 to 10 g, more preferably from 1 to 5 g, per liter of
the color developing solution.
The color developing solution of the present invention can contain a
compound represented by formula (I). The compound represented by formula
(I) is a compound directly preserving a color developing agent. In the
present invention, it is preferable that hydroxyamine and derivatives
thereof having no "A" of formula (I) are not substantially used is
combination. The term "not substantially used" as used herein means the
amount of the used hydroxyamine and derivatives thereof is 0.01 mol/l or
less and preferably 0 mol/l.
The color developing solution of the present invention may contain a
fluorescent brightening agent. As a fluorescent brightening agent,
4,4'-diamino-2,2'-disulfostilbene type compounds are preferred. The
addition amount of the fluorescent brightening agent is generally from 0
to 5 g and preferably from 0.1 to 4 g per liter of the color developing
solution.
Furthermore, the color developing solution of the present invention may
contain various surface active agents such as alkylsulfonic acids,
arylphosphonic acids, aliphatic carboxylic acids, and aromatic carboxylic
acids, if desired.
The color developing processing time in accordance with the present
invention is generally from 30 to 300 seconds, and preferably from 45 to
200 seconds in view of the remarkable effects of the present invention.
Furthermore, the processing temperature is generally from 30 to 45.degree.
C., preferably from 35 to 40.degree. C. in view of the remarkable effects
of the present invention.
Moreover, the "opening rate" as defined below of a processing tank for the
color developing solution in accordance with the present invention is
preferably from 0 to 0.1 cm.sup.-1 in view of stability of the color
developing solution of the present invention.
##EQU1##
In continuous processing, the opening rate is preferably from 0.001 to 0.05
cm.sup.-1, and more preferably from 0.002 to 0.03 cm.sup.-1 in practical
use.
It is well known that when a hydroxylamine is used as a preservative,
decomposition of color developing agent generally occurs upon heating or
in the presence of a small amount of a metal, even if an opening rate of
the tank for the color developing solution is minimized. On the other
hand, with the color developing solution of the present invention, the
above described decomposition is remarkably reduced, and the color
developing solution has good preservability and is practically used in
continuous processing with replenishment over a long time period. In view
of the above, the opening rate is preferably as small as possible, and is
most preferably from 0 to 0.002 cm.sup.-1.
On the other hand, the processing solution may be discarded after a
predetermined amount of the light-sensitive material is processed using a
large opening rate. In such a case, the excellent properties of the
present invention are also obtained.
The effects of the present invention are further enhanced by using means
for reducing the opening rate, for example, use of a floating cover, a
seal with a liquid having a higher boiling point and a lower specific
gravity as compared to the developing solution, or a tank having a narrow
slit opening as described in JP-A-63-131138.
The present invention can be applied to both processing using an automatic
developing machine and manual processing, but is preferably practiced
using an automatic developing machine. When using an automatic developing
machine, one or more tanks for the color developing solution can be
employed. For the purpose of conducting a lower level of replenishment, it
is preferred to use a multistage orderly current replenishment system
comprising a plurality of tanks, and wherein the replenishment is first
introduced into the first tank and the overflow solution is introduced
into the next tank in sequential order.
Furthermore, in order to enhance the effects of the present invention, it
is preferred to supply water to the color developing solution in an amount
corresponding to the amount of evaporation in order to compensate for
concentration of the developing solution. Water added to the color
developing solution is preferably deionized water obtained by ion exchange
treatment, reverse osmosis treatment or distillation.
In the present invention, the color developing solution and the color
developing replenisher are prepared by adding the above chemicals in
sequential order into the predetermined amount of water, and the above
deionized water is preferably used as the water.
In accordance with the present invention, the silver halide color
photographic material is imagewise exposed, subjected to color development
processing as described above, and then processed with a processing
solution having a bleaching ability.
The processing solution having a bleaching ability for use in the present
invention is a processing solution which oxidizes metallic silver formed
by the development reaction and colloidal silver contained in the
photographic material to convert to a soluble silver salt such as a silver
thiocyanate complex salt or an insoluble silver salt such as silver
bromide. The processing solution having a bleaching ability includes, for
example, a bleaching solution and a bleach-fixing solution.
Bleaching agents for use in the processing solution include oxidizing
agents, for example, ferric complex salts such as fericyanide iron complex
and ferric citrate complex, persulfates, or peroxides such as hydrogen
peroxide, but aminopolycarboxylic acid ferric complex salts, i.e., complex
salts of ferric ion and aminopolycarboxylic acids or the salts thereof, is
preferably employed.
Useful examples of the aminopolycarboxylic acids and salts thereof are set
forth below.
(1) Diethylenetriaminepentaacetic acid
(2) Diethylenetriaminepentaacetic acid pentasodium salt
(3) Ethylenediamine-N-(.beta.-oxyethyl)-N,N',N'-triacetic acid
Ethylenediamine-N-(.beta.-oxyethyl)-N,N',N'-triacetic acid trisodium salt
Ethylenediamine-N0(.beta.-oxyethyl)-N,N',N'-triacetic acid triammonium salt
(6) 1,2-Diaminopropanetetraacetic acid
(7) 1,2-Diaminopropanetetraacetic acid disodium salt
(8) Nitrilotriacetic acid
(9) Nitrilotriacetic acid sodium salt
(10) Cyclohexanediaminetetraacetic acid
(11) Cyclohexanediaminetetraacetic acid disodium salt
(12) N-Methyliminodiacetic acid
(13) Iminodiacetic acid
(14) Dihydroxyethylglycine
(15) Ethyl ether diaminetetraacetic acid
(16) Glycol ether diaminetetraacetic acid
(17) Ethylenediaminetetrapropionic acid
(18) 1,3-Diaminopropanetetraacetic acid
(19) Ethylendiaminetetraacetic acid
As a matter of course, the aminopolycarboxylic acids or salts thereof are
not limited to the above compounds.
Of the above-listed compounds, Compounds (1), (2), (6), (7) , (10), (11),
(12), (16), (18) and (19) are particularly preferred.
The aminopolycarboxylic acid ferric complex salt may be used in the form of
a complex salt or may be formed in a solution using a ferric salt such as
ferric sulfate, ferric chloride, ferric nitrate, ammonium ferric sulfate,
or ferric phosphate, and an aminopolycarboxylic acid. When using a complex
salt, the complex salt may be used alone or in combination of two or more
complex salts. On the other hand, when the complex salt is formed in a
solution using a ferric salt and an aminopolycarboxylic acid, one or more
kinds of the ferric salt may be used and also one or more kind of the
aminopolycarboxylic acid may be used. Also, in any case, the
aminopolycarboxylic acid(s) may be used in excess of the amount required
for forming the ferric complex salt.
At least one of the above described ferric (Fe(III)) complex salts of the
aminopolycarboxylic acids excluding Compound (19) and an
ethylenediaminetetraacetic acid ferric complex salt may be used in
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