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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 and more particularly, to a method for
processing a silver halide color photographic material with extremely
improved silver removal, in which the leuco formation of dyes is fully
prevented despite rapid processing. Further it relates to a method for
processing a silver halide color photographic material in which the
formation of color stain is prevented as well.
BACKGROUND OF THE INVENTION
Color developing solutions containing an aromatic primary amine color
developing agent have been employed for the purpose of forming color
images and, at present, are basic to image formation in color photography.
However, as is well known, the above described color developing solution
has the problem that it tends to be easily oxidized by the air or metals,
and in the case of using the oxidized color developing solution in order
to form color images, increase in fog, changes in sensitivity and
gradation occur and desired photographic properties cannot be obtained.
In particular, with the recent trend of shortening time for processing, the
change in photographic properties tends to increase during continuous
processing and a severe problem of color stain formation may occur in some
cases. Particularly, such a problem is apt to occur when a desilvering
step and a water washing step are shortened.
Various reasons for the change in photographic properties and the
occurrence of color stain in continuous processing are considered likely.
For example,
A: a color developing solution is degraded with the lapse of time, as a
result, the photographic properties change and the oxidation product of a
developing agent adheres to photographic light-sensitive materials,
resulting in the formation of color stain;
B: a color developing agent is carried over into a bleaching solution or a
bleach-fixing solution and oxidized to form fog and stain,
C: a substance dissolved out from photographic light-sensitive materials is
accumulated in a color developing solution and adheres to the photographic
light-sensitive materials to form color stain,
D: due to insufficient washing out of dyes or sensitizing dyes incorporated
in photographic light-sensitive materials the photographic light-sensitive
materials are colored; or
E: a bleach-fixing solution or a subsequent rinse solution is degraded with
the lapse of time and color stain occurs.
Particularly, in order to solve problems A and B, it is an indispensable
condition to improve the stability of a color developing solution. A
sulfite ion has been well known as a preservative for the purpose of
increasing stability of a color developing solution. It is also known that
incorporation of various sulfites into a color developing solution is
effective to prevention from color stain. On the other hand, such a
sulfite ion has undesirable effects on photographic properties, in that it
deteriorates color forming properties and dissolves silver halide.
In recent years, it has been strongly desired to accelerate processing,
that is, to shorten the time necessary for processing. In color
development processing, there is a strong need to shorten the time for the
desilvering step which occupies nearly one half of the total processing
time.
In general, ferricyanides, dichromates, ferric chloride,
aminopolycarboxylic acid ferric complex salts, and persulfates are known
as bleaching agents.
However, both ferricyanides and dichromates have the problem of
environmental pollution with respect to cyanide compounds and hexa-valent
chromium compounds. Thus, their use requires special treatment equipment.
Ferric chloride also has various practical problems of the formation of
iron hydroxide and the occurrence of stain during a water washing step
provided thereafter. With respect to persulfates, there is a problem that
their bleaching function is very weak and thus a substantially long
bleaching time is required.
On the other hand, aminopolycarboxylic acid ferric complex salts
(particularly, ethylenediaminetetraacetic acid ferric complex salt) are
bleaching agents most widely employed at present, in view of reduced
problems of environment pollution and no problem of storage. In order to
render the desilvering step rapid, there have been known a bleach-fixing
solution, which contains an aminopolycarboxylic acid ferric complex salt
and a thiosulfate in a single solution, as described in German Patent No.
866,605. However, the bleaching power of the solution is very weak, since
an aminopolycarboxylic acid ferric complex salt which is weak in oxidizing
power (bleaching power) and a thiosulfate which has a reducing power
coexist in a single solution. Therefore, it is very difficult for the
bleach-fixing solution to sufficiently achieve desilvering of color
photographic light-sensitive materials and consequently it can not be
employed for practical use.
Therefore, for the purpose of increasing the bleaching power there has been
proposed a method wherein various bleach accelerating agents are added to
a bleaching bath, a bleach fixing bath or a prebath thereof. Examples of
such bleach accelerating agents include ammonium bromide as described in
JP-A-Nos. 51-87036 (the term "JP-A" as used herein means an "unexamined
published Japanese patent application"), a water-soluble iodide salt as
described in British Patent No. 926,569, and a halide salt as described in
JP-B-Nos. 53-11854 (the term "JP-B" as used herein means an "examined
Japanese patent publication").
However, it has been found that when these halide salts are added to a
bleach-fixing solution, the desilvering property is not sufficiently
improved and they are almost in effective to prevent color stain which may
occur in the case of rapid processing or continuous processing of color
photographic light-sensitive materials.
Further, when bleach-fixing processing is conducted using a bleach-fixing
solution containing an aminopolycarboxylic acid metallic complex salt such
as EDTA ferric complex salt, just after a step with a reducing agent is
carried over to the bleach-fixing bath with the photographic material and
the aminopolycarboxylic acid metallic complex salt is reduced with the
reducing agent ptesent in the bleach-fixing solution. The resulting
reduction product of aminopolycarboxylic acid metallic complex salt may
reduce a colored dye formed, particularly a cyan dye, to form a leuco dye,
and as a result, insufficient color restration occurs.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a method for processing a
silver halide color photographic material which provides extremely
improved desilvering even in rapid processing.
Another object of the present invention is to provide a method for
processing a silver halide color photographic material which provides
improved color restoration.
A further object of the present invention is to provide a method for
processing a silver halide color photographic material in which color
stain is prevented.
Other objects of the present invention will become apparent from the
following description and examples.
It has been found that these and other objects of the present invention are
effectively accomplished by a method for processing a silver halide color
photographic material comprising the steps of (a) developing an imagewise
exposed silver halide color photographic material with a color developing
solution substantially free from sulfite ions; and
(b) immediately contacting the developed silver halide color photographic
material with a bleach-fixing solution containing at least one of (i) from
1.times.10.sup.-2 mol to 2 mol of bromide ions and (ii) from
5.times.10.sup.-4 mol to 5.times.10.sup.-2 mol of iodide ions per liter of
the bleach-fixing solution.
DETAILED DESCRIPTION OF THE INVENTION
As described above, it has been known that desilvering is improved by means
of incorporation of a halide ion into a bleach-fixing solution. However,
it is unexpected that desilvering is remarkably improved by employing a
color developing solution which does not substantially contain a sulfite
ion as a bath preceding the bleach-fixing solution, since the possibility
of improvement in desilvering by eliminating a sulfite ion from a color
developing solution has not been completely known.
On the other hand, it is expected in the art that the problem of color
stain will become serious by substantially eliminating a sulfite ion from
a color developing solution. However, it surprisingly has now been found
that an equivalent or better level of color stain prevention compared to
using a sulfite ion in a color developing solution can be obtained by
incorporating the specific amount of a halide ion as described above into
a bleach-fixing solution without adding a sulfite ion to the color
developing solution. Furthermore, it is also effective to improve the
color restoration.
The bromide ion and iodide ion which can be used in the present invention
are preferably added to the bleach-fixing solution in the form of a
water-soluble bromide salt or iodide salt. Specific examples of these
compounds include an alkali metal salt, an ammonium salt and an alkaline
earth metal salt of the bromide ion or iodide ion, for example, ammonium
bromide, sodium bromide, potassium bromide, ammonium iodide, sodium
iodide, and potassium iodide.
While preferred effects are obtained by the bromide ion concentration of
from 1.times.10.sup.-2 mol to 2 mol per liter and the iodide ion
concentration of from 5.times.10.sup.-4 mol to 5.times.10.sup.-2 mol per
liter, respectively, the bromide ion concentration is particularly
preferably from 1.times.10.sup.-2 mol to 5.times.10.sup.-1 mol per liter
and the iodide concentration is particularly preferably from
5.times.10.sup.-4 mol to 1.times.10.sup.-2 mol per liter.
When the bromide ion concentration is less than 1.times.10.sup.-2 mol per
liter of the bleach-fixing solution, the bleach-fixing accelerating effect
may not be exhibited and thus it is not preferred in view of the decrease
in the remaining amount of silver which is the object of the present
invention. On the other hand, when the concentration exceeds 2 mol per
liter, insufficient fixing may occur and it is not preferred in view of
insufficient desilveration.
Also, when the iodide ion concentration is less than 5.times.10.sup.-4 mol
per liter of the bleach-fixing solution, it is not preferred in view of
the decrease in the remaining amount of silver, just as when the bromide
ion concentration is less than 1.times.10.sup.-2 mol per liter. On the
other hand, the iodide ion concentration exceeds 5.times.10.sup.-2 mol per
liter, it is not preferred in view of insufficient desilveration, just as
when the bromide ion concentration exceeds 2 mol per liter.
Further, when the bromide ion and iodide ion are used together, in the
bleach-fixing solution the bromide ion can be incorporated in a range from
1.times.10.sup.-2 mol to 2 mol, preferably from 1.times.10.sup.-2 to 1
mol, per liter of the solution, and the iodide ion can be incorporated in
a range from 5.times.10.sup.-4 mol to 5.times.10.sup.-2 mol, preferably
from 5.times.10.sup.-4 mol to 1.times.10.sup.-2 mol, per liter of the
solution.
The objects of the present invention can be achieved by using any of the
bromide ion and iodide ion, and the selection thereof to be used can be
appropriately determined depending on the conditions of use.
In order to control the bromide ion and/or iodide ion concentration in the
above described range, the compound can be directly added to the
bleach-fixing solution, or may be added together with a replenisher.
Further, it may partially carried over from the preceding bath (i.e. color
developing solution).
The terminology "color developing solution substantially free from a
sulfite ions" as used in the present invention means a color developing
solution containing no sulfite ion or containing a sulfite ion in an
amount that does not effect photographic properties. More specifically,
the amount of sulfite ion present in the color developing solution is in a
range from 0 mol/l to 0.005 mol/l, preferably from 0 mol/l to 0.002 mol/l.
Further, it is preferred that the color developing solution used in the
present invention is substantially free from benzyl alcohol in view of
further improvement in desilvering and prevention of the formation of fog
and the increase in stain after processing. The term "color developing
solution substantially free from benzyl alcohol" as used herein means a
color developing solution containing benzyl alcohol in an amount of not
more than 5.0 ml per liter, preferably not more than 2 ml per liter of the
solution. More preferably, the color developing solution does not contain
benzyl alcohol at all.
In the present invention, it is preferred to incorporate an organic
preservative into the color developing solution in order to effectively
prevent the occurrence of color stain.
The organic preservatives which can be used in the present invention
include all organic compounds which can retard the degradation rate of the
aromatic primary amine color developing agent when they are added to a
processing solution for the color photographic light-sensitive materials.
More specifically, organic compounds which prevent the oxidation of the
color developing agent by the air, etc., are exemplified. Among them,
hydroxylamines, hydroxamic acids, hydrazines, hydrazides, phenols,
.alpha.-hydroxyketones, .alpha.-aminoketones, saccharides, monoamines,
diamines, polyamines, quaternary ammonium salts, nitroxy radicals,
alcohols, oximes, diamide compounds, and condensed ring amines, are
particularly effective organic preservatives.
These compounds are described, for example, in Japanese Patent Application
Nos. 61-197760 and 61-198987, JP-A-Nos. 63-58346, JP-A-Nos. 63-4235,
JP-A-Nos. 63-21647, JP-A-Nos. 63-30845, JP-A-Nos. 63-43138, JP-A-Nos.
63-43140, JP-A-Nos. 63-44655, JP-A-Nos. 63-44656 and JP-A-Nos. 63-44657,
EP-A No. 254280, U.S. Pat. Nos. 3,615,503 and 2,494,903, JP-A-Nos.
52-143020, and JP-B-Nos. 48-30496.
General formulae and examples of specific compounds of preferred organic
preservatives used are illustrated below, but the present invention is not
to be construed as being limited thereto.
The amount of the compound described below to be incorporated into the
color developing solution is in a range from 0.005 mol/l to 0.5 mol/l,
preferably from 0.03 mol/l to 0.1 mol/l.
Of the hydroxylamines, those represented by the following general formula
(I) are preferred.
##STR1##
wherein R.sup.11 and R.sup.12, which may be the same or different, each
represents hydrogen, an unsubstituted or substituted alkyl group, an
unsubstituted or substituted alkenyl group, an unsubstituted or
substituted aryl group or an unsubstituted or substituted heteroaromatic
group, provided that at least one of R.sup.11 and R.sup.12 is a group
other than hydrogen, and R.sup.11 and R.sup.12 may be linked to form a
heterocyclic ring together with the nitrogen atom.
In general formula (I), R.sup.11 and R.sup.12 each preferably represents an
alkyl group or an alkenyl group. The number of carbon atoms included
therein is preferably from 1 to 10, and particularly preferably from 1 to
5.
Suitable examples of the nitrogen-containing heterocyclic group which is
formed by linking R.sup.11 and R.sup.12 include a piperidyl group, a
pyrrolidyl group, an N-alkylpiperazyl group, a morpholyl group, an
indolinyl group and a benzotriazolyl group.
Preferred examples of the substituents for the group represented by
R.sup.11 or R.sup.12 include a hydroxyl group, an alkoxy group, an alkyl-
or aryl-sulfonyl group, an amido group, a carboxyl group, a cyano group, a
sulfo group, a nitro group and an amino group.
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.
##STR2##
Of the hydroxamic acids, those represented by the following general formula
(II) are preferred.
##STR3##
wherein A.sup.21 represents hydrogen, a substituted or unsubstituted alkyl
group, a substituted or unsubstituted aryl group, a substituted or
unsubstituted amino group, a substituted or unsubstituted heterocyclic
group, a substituted or unsubstituted alkoxy group, a substituted or
unsubstituted aryloxy group, a substituted or unsubstituted carbamoyl
group, a substituted or unsubstituted sulfamoyl group, an acyl group, a
carboxyl group, a hydroxyamino group, or a hydroxyaminocarbonyl group;
X.sup.21 represents
##STR4##
--SO.sub.2 -- or --SO--; R.sup.21 represents hydrogen, a substituted or
unsubstituted alkyl group or a substituted or unsubstituted aryl group;
A.sup.21 and R.sup.21 may be linked to form a ring; and Y.sup.21
represents hydrogen or a group capable of forming hydrogen by hydrolysis.
Suitable examples of the substituents for the group represented by A.sup.21
include a halogen atom, an aryl group, an alkyl group, and an alkoxy
group.
A.sup.21 preferably represents a substituted or unsubstituted alkyl, aryl,
amino, alkoxy or aryloxy group. Particularly preferred groups for A.sup.21
include a substituted or unsubstituted amino, alkyl or aryloxy group. The
number of carbon atoms included therein is preferably from 1 to 10.
X.sup.21 preferably represents
##STR5##
Suitable examples of the substituents for the group represented by R.sup.21
include those as described for A.sup.21. R.sup.21 is preferably a hydrogen
atom.
Specific examples of the compounds represented by the general formula (II)
are set forth below, but the present invention is not to be construed as
being limited thereto:
##STR6##
Of the hydrazines and hydrazides, those represented by the following
general formula (III) are preferred.
##STR7##
wherein R.sup.31, R.sup.32 and R.sup.33, which may be the same or
different, each represents hydrogen, a substituted or unsubstituted alkyl,
aryl or heterocyclic group; R.sup.34 represents a hydroxyl group, a
hydroxylamino group, a substituted or unsubstituted alkyl, aryl,
heterocyclic, alkoxy, aryloxy, carbamoyl or amino group; X.sup.31
represents a divalent group selected from --CO--, --SO.sub.2 -- or
##STR8##
n is 0 or 1, and when n is 0, R.sup.34 represents a substituted or
unsubstituted alkyl, aryl or heterocyclic group; and R.sup.33 and R.sup.34
may be linked to form a hetero ring.
In the general formula (III), R.sup.31, R.sup.32 and R.sup.33 each
preferably represents hydrogen or an alkyl group. Particularly, it is
preferred that R.sup.31 and R.sup.32 both are hydrogen.
In the general formula (III), R.sup.34 preferably represents an alkyl
group, an aryl group, an alkoxy group, a carbamoyl group or an amino
group.
In the general formula (III), X.sup.31 preferably represents --CO-- or
--SO.sub.2 --, and particularly preferably represents --CO--.
Specific examples of the compounds represented by the general formula (III)
are set forth below, but the present invention is not to be construed as
being limited thereto.
##STR9##
Of the phenols, those represented by the following general formula (IV) are
preferred.
##STR10##
wherein R.sup.41 represents hydrogen, a halogen atom, an alkyl group, an
aryl group, an alkoxy group, an aryloxy group, a carboxyl group, a sulfo
group, a carbamoyl group, a sulfamoyl group, an amido group, a sulfonamido
group, a ureido group, an alkylthio group, an arylthio group, a nitro
group, a cyano group, an amino group, a formyl group, an acyl group, a
sulfonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an
alkoxysulfonyl group or an aryloxysulfonyl group; plural R.sup.41 groups
may be the same or different; and two adjacent R.sup.41 groups may be
linked to form a ring; R.sup.42 represents hydrogen or a group capable of
forming hydrogen by hydrolysis; and m and n each is an integer of from 1
to 5 (where m+n.ltoreq.6).
In the general formula (IV), the group represented by R.sup.41 may be
further substituted. Suitable examples of the substituents include a
halogen atom, an alkyl group, an aryl group, a hydroxy group, and an
alkoxy group. The ring formed by two adjacent R.sup.41 groups may be a
5-membered or 6-membered ring, may be saturated or unsaturated, and may be
composed of a carbon atom, a hydrogen atom, a halogen atom, an oxygen
atom, a nitrogen atom and a sulfur atom.
In the general formula (IV), R.sup.41 preferably represents an alkyl group,
a halogen atom, an alkoxy group, an alkylthio group, a carboxy group, a
sulfo group, a carbamoyl group, a sulfamoyl group, an amino group, an
amido group, a sulfonamido group, a nitro group, or a cyano group. Of
these groups, an alkoxy group, an alkylthio group, an amino group and a
nitro group are particularly preferred, and it is more preferred that such
a group is present at the ortho position or the para position to the group
OR.sup.42. Further, the number of carbon atoms contained in R.sup.41 is
preferably from 1 to 10, and particularly preferably from 1 to 6.
In the general formula (IV), R.sup.42 preferably represents hydrogen or a
group capable of forming hydrogen by hydrolysis having from 1 to 5 carbon
atoms. Further, when two or more OR.sup.42 's are present, it is preferred
that they are positioned with respect to each other at ortho or para
positions.
Specific examples of the compounds represented by the general formula (IV)
are set forth below, but the present invention is not to be construed as
being limited thereto.
##STR11##
Of the .alpha.-hydroxyketones and .alpha.-aminoketones, those represented
by the following general formula (V) are preferred.
##STR12##
wherein R.sup.51 represents hydrogen, or a substituted or unsubstituted
alkyl, aryl, alkoxy, aryloxy or amino group; R.sup.52 represents hydrogen,
or a substituted or unsubstituted alkyl or aryl group; R.sup.51 and
R.sup.52 may be linked to form a carbocyclic ring or a heterocyclic ring;
and X.sup.51 represents a hydroxyl group or a substituted or unsubstituted
amino group.
In the general formula (V), R.sup.51 preferably represents hydrogen, an
alkyl group, an aryl group or an alkoxy group, and R.sup.52 preferably
represents hydrogen or an alkyl group.
Specific examples of the compounds represented by the general formula (V)
are set forth below, but the present invention is not to be construed as
being limited thereto.
##STR13##
Saccharides are also preferred organic preservatives. Saccharides (also
usually called "carbohydrates") are classified into monosaccharides and
polysaccharides, and most of them are represented by the general formula
C.sub.n H.sub.2m O.sub.m. Monosacharides generally include aldehydes and
ketones of polyvalent alcohols (called aldoses and ketoses, respectively),
and also derivatives thereof such as reduction derivatives thereof,
oxidation derivatives thereof, dehydration derivatives thereof, amino
sugar, and thio sugar. Polysaccharides are products which is formed by
dehydration condensation of two or more of the monosaccharides described
above.
Of these saccharides, those more preferred are aldoses having a reducing
aldehyde group and derivatives thereof, and monosaccharides thereof are
particularly preferred.
Specific examples of the saccharides are set forth below, but the present
invention is not to be construed as being limited thereto.
##STR14##
Of the monoamines, those represented by the general formula (VII) are
preferred.
##STR15##
wherein R.sup.71, R.sup.72 and R.sup.73, which may be the same or
different, each represents hydrogen, an alkyl group, an alkenyl group, an
aryl group, an aralkyl group or a heterocyclic group; and R.sup.71 and
R.sup.72, R.sup.71 and R.sup.73 or R.sup.72 and R.sup.73 may be linked to
form a nitrogen-containing heterocyclic ring.
In the general formula (VII), the group represented by R.sup.71, R.sup.72
or R.sup.73 may be substituted. Suitable examples of the substituents for
the group represented by R.sup.71, R.sup.72 or R.sup.73 include those
described for R.sup.11 and R.sup.12 in general formula (I) above. In the
general formula (VII), R.sup.71, R.sup.72 and R.sup.73 each preferably
represents hydrogen or an alkyl group.
Specific examples of the compounds represented by the general formula (VII)
are set forth below, but the present invention is not to be construed as
being limited thereto.
##STR16##
Of the diamines, those represented by the following general formula (VIII)
are preferred.
##STR17##
wherein R.sup.81, R.sup.82, R.sup.83 and R.sup.84, which may be the same
or different, each represents hydrogen, an alkyl group, an alkenyl group,
an aryl group, an aralkyl group or a heterocyclic group; and R.sup.85
represents a divalent organic group.
The divalent organic group represented by R.sup.85 includes an alkylene
group, an arylene group, an aralkylene group, an alkenylene group and a
heterocyclic group.
In the general formula (VIII), R.sup.81, R.sup.82, R.sup.83 and R.sup.84
each preferably represents hydrogen or an alkyl group, and R.sup.85
preferably represents an alkylene group.
Specific examples of the compounds represented by the general formula
(VIII) are set forth below, but the present invention is not to be
construed as being limited thereto.
##STR18##
Of the polyamines, those represented by the following general formula (IX)
are preferred.
##STR19##
wherein R.sup.91, R.sup.92, R.sup.93 and R.sup.94, which may be the same
or different, each represents hydrogen, an alkyl group, an alkenyl group,
an aryl group, an aralkyl group or a heterocyclic group; R.sup.95,
R.sup.96 and R.sup.97 each represents a divalent organic group; X.sup.91
and X.sup.92 each represents
##STR20##
--O--, --S--, --CO--, --SO.sub.2 --, --SO--, or a combination thereof;
R.sup.98 has the same meaning as R.sup.91 ; and m represents 0 or an
integer of at least 1.
The divalent organic group represented by R.sup.95, R.sup.96 or R.sup.97
includes those described for R.sup.85 in general formula (VIII) above. The
upper limit of m is not particularly restricted, and high molecular weight
compounds may be employed as far as they are water-soluble. However, it is
usually preferred that m is in a range of from 1 to 3.
Specific examples of the compounds represented by the general formula (IX)
are set forth below, but the present invention is not to be construed as
being limited thereto.
##STR21##
Of the quaternary ammonium salts, those represented by the following
general formula (X) are preferred.
##STR22##
wherein R.sup.101 represents a n-valent organic group; R.sup.102,
R.sup.103 and R.sup.104, which may be the same or different, each
represents an organic group, and at least two of R.sup.102, R.sup.103 and
R.sup.104 may be linked to form a heterocyclic group containing the
quaternary ammonium atom; n represents an integer of at least 1; and
X.sup..crclbar. represents a counter anion.
In general formula (X), R.sup.102, R.sup.103 and R.sup.104 each preferably
represents a substituted or unsubstituted alkyl group. Further, it is most
preferred that at least one of R.sup.102, R.sup.103 and R.sup.104 is a
hydroxyalkyl group, an alkoxyalkyl group or a carboxyalkyl group. n is
preferably an integer of from 1 to 3, and more preferably 1 or 2.
Specific examples of the compounds represented by the general formula (X)
are set forth below, but the present invention 13 not to be construed as
being limited thereto.
##STR23##
Of the nitroxy radicals, those represented by the following general formula
(XI) are preferred.
##STR24##
wherein R.sup.111 and R.sup.112, which may be the same or different, each
represents hydrogen an alkyl group, an aryl group or a heterocyclic group.
The alkyl group, aryl group or heterocyclic group represented by R.sup.111
or R.sup.112 may have one or more substituents. Suitable examples of the
substituents include a hydroxyl group, an oxo group, a carbamoyl group, an
alkoxy group, a sulfamoyl group, a carboxy group, and a sulfo group.
Suitable examples of the heterocyclic group include a pyridyl group, and a
piperidyl group.
In the general formula (XI), R.sup.111 and R.sup.112 each preferably
represents a substituted or unsubstituted aryl group or a tertiary alkyl
group (for example, tert-butyl).
Specific examples of the compounds represented by the general formula (XI)
are set forth below, but the present invention is not to be construed as
being limited thereto.
##STR25##
Of the alcohols, those represented by the following general formula (XII)
are preferred.
##STR26##
wherein R.sup.121 represents a hydroxyl-substituted alkyl group; R.sup.122
represents an unsubstituted alkyl group or a hydroxyl-substituted alkyl
group; R.sup.123 represents hydrogen, an unsubstituted alkyl group or a
hydroxyl-substituted alkyl group; and X.sup.121 represents a hydroxyl
group, a carboxyl group, a sulfo group, a nitro group, an unsubstituted
alkyl group, a hydroxyl-substituted alkyl group, an unsubstituted or
substituted amino group or an unsubstituted or substituted sulfonamido
group.
In the general formula (XII), X.sup.121 preferably represents a hydroxyl
group, a carboxyl group or a hydroxyl-substituted alkyl group.
Specific examples of the compounds represented by the general formula (XII)
are set forth below, but the present invention is not to be construed as
being limited thereto.
##STR27##
Of the alcohols, those represented by the following general formula (XIII)
are also preferred.
##STR28##
wherein R.sup.131 and R.sup.133, which may be the same or different, each
represents hydrogen or a substituted or unsubstituted alkyl group;
R.sup.132 represents hydrogen, a substituted or unsubstituted alkyl group,
a hydroxy group or a substituted or unsubstituted alkoxy group; and n is a
positive integer up to 500.
In the general formula (XIII), the alkyl group represented by R.sup.131,
R.sup.132 or R.sup.133 has preferably not more than 5 carbon atoms, and
more preferably not more than 2 carbon atoms. R.sup.131, R.sup.132 and
R.sup.133 particularly preferably each represents hydrogen or a methyl
group and most preferably each represents hydrogen. n preferably is a
positive integer from 3 to 100, and more preferably is a positive integer
from 3 to 30.
Specific examples of the compounds represented by the general formula
(XIII) are set forth below, but the present invention is not to be
construed as being limited thereto.
##STR29##
Of the oximes, those represented by the following general formula (XIV) are
preferred.
##STR30##
wherein R.sup.141 and R.sup.142, which may be the same or different, each
represents hydrogen, a substituted or unsubstituted alkyl group or a
substituted or unsubstituted aryl group, and R.sup.141 and R.sup.142 may
be linked to form a ring.
In the general formula (XIV), R.sup.141 and R.sup.142 each preferably
represents an unsubstituted alkyl group or an alkyl group substituted with
one or more substituents selected from a halogen atom, a hydroxyl group,
an alkoxy group, an amino group, a carboxyl group, a sulfo group, a
phosphonic acid group and a nitro group. Further, the total number of
carbon atoms included in the compound represented by the general formula
(XIV) is preferably not more than 30, more preferably not more than 20.
Specific examples of the compounds represented by the general formula (XIV)
are set forth below, but the present invention is not to be construed as
being limited thereto.
##STR31##
Of the diamide or disulfonamide compounds, those represented by the
following general formula (XV) are preferred.
##STR32##
wherein X.sup.151 and X.sup.152, which may be the same or different, each
represents --CO-- or --SO.sub.2 --; R.sup.151, R.sup.152, R.sup.153,
R.sup.154, R.sup.155 and R.sup.156, which may be the same or different,
each represents hydrogen or an unsubstituted or substituted alkyl group;
R.sup.157 represents an unsubstituted or substituted alkylene group, an
unsubstituted or substituted arylene group or an unsubstituted or
substituted aralkylene group; and m.sub.1, m.sub.2 and n, which may be the
same or different, each is 0 or 1.
Specific examples of the compounds represented by the general formula (XV)
are set forth below, but the present invention is not to be construed as
being
##STR33##
Of the condensed ring amines, those represented by the general formula
(XVI) are preferred.
##STR34##
wherein X.sup.161 represents a trivalent atomic group necessary to
complete a condensed ring; and R.sup.161 and R.sup.162, which may be the
same or different, each represents a substituted or unsubstituted alkylene
group, a substituted or unsubstituted arylene group, a substituted or
unsubstituted alkenylene group or a substituted or unsubstituted
aralkylene group.
Of the compounds represented by the general formula (XVI), those
particularly preferred are compounds represented by the following general
formula (I-a) or (I-b)
##STR35##
wherein X.sup.162 represents
##STR36##
R.sup.161 and R.sup.162 each has the same meaning as defined in general
formula (XVI); and R.sup.163 represents the group R.sup.161
##STR37##
In the general formula (I-a), X.sup.162 preferably represents
##STR38##
The number of carbon atoms included in each of R.sup.161, R.sup.162 and
R.sup.163 is preferably not more than 6, more preferably not more than 3,
and most preferably not more than 2. R.sup.161, R.sup.162 and R.sup.163
each preferably represents an alkylene group or an arylene group, and most
preferably an alkylene group.
##STR39##
wherein R.sup.161 and R.sup.162 each has the same meaning as defined in
the general formula (XVI).
In the general formula (I-b), the number of carbon atoms included in each
of R.sup.161 and R.sup.162 is preferably not more than 6. R.sup.161 and
R.sup.162 each preferably represents an alkylene group or an arylene
group, and most preferably an alkylene group.
Of the compounds represented by the general formulae (I-a) and (I-b), those
represented by the general formula (I-a) are preferred.
Specific examples of the compounds represented by the general formula (XVI)
are set forth below, but the present invention is not to be construed as
being limited thereto.
##STR40##
Many of the compounds represented by the general formula (XVI) according to
the present invention are easily available as commercial products.
It is preferred that two or more kinds of these preservatives are employed
in combination in view of their preservative function Particularly,
combinations of at least one compound selected from those represented by
the general formulae (I) to (V) and saccharides and at least one compound
selected from those represented by the general formulae (VII) to (XVI) are
preferably employed. Further, it is more particularly preferred that at
least one compound selected from those represented by the general formulae
(I) and (III) and at least one compound selected from those represented by
the general formulae (VII) and (XVI) are employed together.
These compounds represented by the general formulae (I) to (XVI) can easily
be synthesized by referring to, for example, Japanese Patent Application
Nos. 61-197760 and 61-198987, JP-A-58346, JP-A-63-4235, JP-A-63-21647,
JP-A-63-30845, JP-A-63-43138, JP-A-63-43140, JP-A-63-44655, JP-A-63-44656
and JP-A-63-44657, EP-A-No. 254280, U.S. Pat. Nos. 3,615,503 and
2,494,903, JP-A-No. 52-143020, and JP-B-No. 48-30496.
Now, the color developing solution which can be used in the present
invention is described in detail below.
The color developing solution used in the present invention contains a
known aromatic primary amine color developing agent. Preferred examples
thereof are p-phenylenediamine derivatives. Typical examples of the
p-phenylenediamine derivative used 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: 4-[N-Ethyl-N-(.beta.-hydroxyethyl)amino]aniline
D-3: 2-Methyl-4-[N-ethyl-N-(.beta.-hydroxyethyl)amino]aniline
D-4: 4-Amino-3-methyl-N-ethyl-N-[.beta.-(methanesulfonamido)ethyl]aniline
These p-phenylenediamine derivatives may be in the form of salts such as
sulfates, hydrochlorides, or p-toluenesulfonates.
The aromatic primary amine developing agent is used in an amount of from
about 0 1 g to about 20 g and preferably from about 0.5 g to about 10 g
per liter of the developing solution.
The color developing solution used in the present invention has a pH which
ranges preferably from 9 to 12 and more preferably from 9 to 11.0. The
color developing solution may also contain any of the compounds that are
known to be usable as components of developing solutions.
In order to maintain the pH in the above-described range, various kinds of
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 to be added to the color developing solution is
preferably 0.1 mol or more and more preferably from 0.1 mol to 0.4 mol per
liter thereof.
In addition, various chelating agents can be used in the color developing
solution according to the present invention for the purpose of preventing
calcium or magnesium precipitation or increasing the stability of the
color developing solution.
Specific examples of the chelating agents used are set forth below, but the
present invention is not to be construed as being limited thereto.
Nitrilotriacetic acid
Diethylenetriaminepentaacetic acid
Ethylenediaminetetraacetic acid
Triethylenetetraminehexaacetic acid
N,N,N-Trimethylene | | |
