FIELD OF THE INVENTION
[0001] The present invention relates to a light-sensitive silver halide photographic material
capable of fast processing and which also has a high speed and high image quality.
The present invention can be utilized as a lightsensitive material that is resistant
to roller marks and hence can obtain an image of high quality even when, for example,
the material is subjected to fast processing in an automatic processor.
BACKGROUND OF THE INVENTION
[0002] Light-sensitive silver halide photographic materials are demanded to be of high speed
and high image quality, and on the other hand required to be processed in a short
time. Particularly in recent years, it is strongly required for them to be rapidly
processed in a short time, with an increase in the consumption of light-sensitive
silver halide photographic materials. For example in the field of X-ray photographic
materials as exemplified by X-ray films for medical use there is an increase in the
number of X-ray photographs taken because of a rapid increase in the number of times
for diagnosis or an increase in test items, and on the other hand it is necessary
to notify as soon as possible the outcome of the diagnosis to those who have been
diagnosed. Particularly in angiography, mid-operation photography etc., it is fundamentally
necessary to view photographs in a time as short as possible.
[0003] With this background, various rapid processing techniques have been attempted. For
example, in image-formation processing, it has been attempted to carry out development
processing at a high pH and a high temperature (30 to 40°C) to accelerate the processing.
However, such a high pH and high temperature condition has brought about a deterioration
of the photographic images obtained. In particular, in instances in which the processing
is carried out with an automatic processor, it has sometimes occurred that the pressure
resistance of light-sensitive materials is deteriorated to make so-called roller marks
owing to the pressure of carrying rollers, thus causing a deterioration of image quality.
[0004] To solve this problem, various techniques have been proposed, but none of them have
been sufficient.
[0005] On the other hand, it is effective to reduce the amount of binders (usually gelatin)
for light-sensitive materials in order to achieve rapid processing, but the reduction
of the amount of binders tends to more deteriorate the pressure resistance, to readily
make the above roller marks or the like.
[0006] Such deterioration of images is not desirable and may possibly cause misdiagnosis
in the case of X-ray light-sensitive materials.
SUMMARY OF THE INVENTION
[0007] The present invention was made on account of the above circumstances, and an object
of the present invention is to provide a light-sensitive silver halide photographic
material that can be free of any deterioration of images as exemplified by the deterioration
of images owing to roller marks, can obtain an image of high quality and also can
be of high speed, even when rapid fast processing is carried out.
[0008] The above object of the present invention was achieved by a light-sensitive silver
halide photographic material comprising a support and, provided on at least one side
thereof, a light-sensitive silver halide emulsion layer, containing a silver halide
emulsion obtained by a method comprising the steps of
adding an aqueous solution of a water-soluble silver salt and an aqueous solution
of a water-soluble halide into an aqueous solution containing a protective colloid
to precipitate silver halide grains, and
coagulating said silver halide grains together with said protective colloid by the
use of a polymer coagulant, and removing a supernatant liquid containing dissolved
matters.
[0009] Namely, in the present invention, incorporation of the above specific emulsion made
it possible to obtain a light-sensitive material that can be satisfactory in every
respect of the rapid processing performance, speed and image quality.
[0010] Because of the superior rapid processing performance of the light-sensitive material
of the present invention, the speed or image quality may not be deteriorated even
when it is subjected to fast processing carried out in the total processing time of
not less than 20 seconds and not more than 3 minutes 30 seconds, and the image quality
deterioration due to roller marks may be substantially avoided even when it is processed
with an automatic processor having rollers.
[0011] Thus, the present invention is suited to the fast processing carried out in the total
processing time of not less than 20 seconds and not more than 3 minutes 30 seconds,
but can also be more preferably used in the rapid processing carried out in the total
processing time of not less than 20 seconds and not more than 90 seconds, and can
be further preferably used in the ultra-rapid processing carried out in not less than
20 seconds and nor more than 60 seconds. For example, even when processing with an
automatic processor is carried out in not less than 20 seconds and not more than 60
seconds, an excellent image can be obtained because of an improvement in the roller-mark-free
performance.
DETAILED DESCRIPTION OF THE INVENTION
[0012] The total processing time mentioned here is meant to be the total time taken after
the tip of a film is inserted to an automatic processor and before the tip of the
film comes out of a drying section, passing through a developing tank, a carrying
path, a fixing tank, a carrying path, a washing tank, a carrying path and the drying
section [in other words, the quotient (sec.) obtained by dividing the whole length
(m) of a processing line by the line conveyance velocity (m/sec). The reason why the
time for passing the carrying paths is included here is, as well known in the present
industrial field, that a solution for the processing swells gelatin films also on
the carrying paths and hence the processing steps can be deemed to substantially proceed
there.
[0013] The light-sensitive material of the present invention comprises a support having
on one side thereof at least one light-sensitive silver halide emulsion layer.
[0014] More specifically, in the present invention, at least one light-sensitive silver
halide emulsion layer may be provided on both sides of a support to give a both-sided
light-sensitive material, or may be provided on one side thereof to give a one-sided
light-sensitive material.
[0015] The light-sensitive silver halide photographic material of the present invention
contains a silver halide emulsion obtained by bringing silver halide grains formed
by adding an aqueous solution of a water-soluble silver salt and an aqueous solution
of a water-soluble halide in an aqueous solution containing a protective colloid,
into coagulation together with the protective colloid by use of a polymer coagulant
followed by removal of dissolved matters (hereinafter referred to as "emulsion according
to the present invention" or so).
[0016] The emulsion according to the present invention may be contained in at least one
of any emulsion layers of the light-sensitive material of the present invention, but
the emulsion according to the present invention may preferably be contained in many
of the emulsion layers, and more preferably in all of the emulsion layers.
[0017] The emulsion according to the present invention is prepared by adding an aqueous
solution of a water-soluble silver salt and an aqueous solution of a water-soluble
halide in an aqueous solution containing a protective colloid, and obtained by bringing
silver halide grains formed thereafter, into coagulation together with the protective
colloid from the state of a suspension by use of a polymer coagulant, followed by
removal of dissolved matters in the suspension.
[0018] Here, the aqueous solution containing a protective colloid refers to an aqueous solution
in which protective colloid is formed by gelatin or other materials capable of constituting
a hydrophilic colloid (e.g. materials capable of serving as a binder), and may preferably
refer to an aqueous solution containing colloidal protective gelatin.
[0019] In instances in which gelatin is used as the above protective colloid in working
the present invention, the gelatin may be either subjected to lime treatment or treated
with use of an acid. Details of the preparation method for the gelatin are described
in Arther Vice, The Macromolecular Chemistry of Gelatin, Academic Press, published
1964.
[0020] Hydrophilic colloids other than the gelatin that can be used as protective colloids
include a variety of synthetic hydrophilic polymer materials as exemplified by proteins
such as gelatin derivatives, graft polymers of gelatin with other polymers, albumin,
and casein; sugar derivatives such as cellulose derivatives including hydroxyethyl
cellulose, carboxymethyl cellulose and cellulose sulfates, sodium alginate, and starch
derivatives: homopolymers or copolymers such as polyvinyl alcohol, polyvinyl alcohol
partial acetal, poly-N-vinyl pyrrolidone, polyacrylate, polymethacrylate, polyacrylamide,
polyvinyl imidazole, and polyvinyl pyrazole.
[0021] In the case of gelatin, the one having a jelly strength of 200 or more when measured
by the PAGI method may preferably be used.
[0022] In the light-sensitive material of the present invention, it is advantageous to use
gelatin as the hydrophilic colloid that can be used in photographic component layers
such as protective layers, backing layers and intermediate layers that are optionally
formed, but it is also possible to use the above hydrophilic colloids other than that
alone or together with the gelatin.
[0023] The aqueous solution of a water-soluble silver salt and aqueous solution of a water-soluble
halide refer to what are reacted to obtain a desired silver halide, and they are appropriately
selected and combined depending on the desired composition of silver halides.
[0024] The polymer coagulant refers to a polymeric material capable of bringing silver halide
grains into coagulation together with the protective colloid. Using such a polymer
coagulant, the gelatin or the like, which is the protective colloid, is coagulated
and formed into a gel, and then the step of removing dissolved matters such as soluble
salts in the solution is carried out (the so-called desalting step).
[0025] In the present invention, various types of agents can be used as the polymer coagulant,
but preferred ones may include a polymeric compound represented by Formula (I), comprising
Chain A and Chain B as shown below. Formula (I)

wherein R₁ and R₂ each represent an aliphatic group which may be the same with or
different from each other; R₃ represents a hydrogen atom, an aliphatic group, an aryl
group or an aralkyl group: X represents -O- or NH- ; M⁺ represents a cation; and n
is an integer of from 10 to 10⁴; provided that either one of two bonding arms in Chain
B may be connected with the R₁ and R₂- bonded tertiary carbon atom in Chain A, and
when X represents -NH- it may form a nitrogen-containing heterocyclic ring together
with R₃.
[0026] Also preferably used is a modified gelatin in which 50 % or more of amino groups
in gelatin molecules has been substituted (hereinafter referred to as an "coagulating
gelatin agent). Examples of the substituents for the amino groups of gelatin are described
in U.S. patents No. 2,91,582, No. 2,164,928 and No. 2,525,753.
[0027] Useful substituents may include;
(1) acyl groups such as alkylacyl, arylacyl, acetyl and substituted or unsubstituted
benzoyl;
(2) carbamoyl groups such as alkylcarbamoyl and arylcarbamoyl;
(3) sulfonyl groups such as alkylsulfonyl and arylsuifonyl;
(4) thiocarbamoyl groups such as alkylthiocarbamoyl and arylthiocarbamoyl;
(5) straight-chain or branched alkyl groups having 1 to 18 carbon atoms; and
(6) aryl groups such as substituted or unsubstituted phenyl or naphthyl and aromatic
heterocyclic group such as pyridyl and furyl.
[0028] Among these preferred modified gelatin (coagulating gelatin agent) include those
substituted with an acyl group (-COR¹) or a carbamoyl group

[0029] The above R¹ represents a substituted or unsubstituted aliphatic group as exemplified
by an alkyl group having1 to 18 carbon atoms and an allyl group, or an aryl group
or aralkyl group as exemplified by a phenethyl group, and R² represents a hydrogen
atom, an aliphatic group, an aryl group or an aralkyl group.
[0030] Particularly preferred ones include instances in which R¹ is an aryl group and R²
is a hydrogen atom.
[0031] Examples of the coagulating gelatin agent used as the polymer coagulant in the present
invention are shown below as substituents for the amino group, but the present invention
is by no means limited by these.
Exemplary coagulating gelatin agents (substituents for the amino group):

[0032] In instances in which the coagulating gelatin agent is used in the step of removing
dissolved matters (desalting), there is no particular limitation on the amount of
the agent to be added, but it is appropriate for it to be added in an amount of from
0.3 to 10 times (by weight) that of the material (preferably gelatin) contained as
a protective colloid at the time of the removing, and particularly preferably 1 to
5 times (by weight).
[0033] In the present invention, silver halide grains are brought into coagulation together
with the protective colloid by use of the polymer coagulant, and, when the coagulating
gelatin agent is used as the polymer coagulant, the pH may be adjusted after the addition
of the coagulating gelatin agent to effect coagulation of a silver halide emulsion.
The pH at which the coagulation is effected may preferably be 5.5 or less, and particularly
preferably 4.5 to 2. There are no particular limitations on the acid used in the adjustment
of the pH, but preferably used are organic acids such as acetic acid, citric acid
and salicylic acid, and inorganic acids such as hydrochloric acid, nitric acid, sulfuric
acid and phosphoric acid. For use in combination with the coagulating gelatin agent,
heavy metal ions may be added as exemplified by magnesium ions, cadmium ions, lead
ions and zirconium ions.
[0034] The removal of the dissolved matters (i.e., desalting) may be carried out once or
may be repeated several times. In instances in which it is repeated several times,
the coagulating gelatin agent may be added every time when the removal is carried
out, but the coagulating gelatin agent may be added only at the beginning.
[0035] Next, description will be made on the instance where the polymeric compound represented
by the above Formula (I) is used in the present invention as the polymer coagulant.
This polymeric compound may preferably have a molecular weight of from 10³ to 10⁶
and more preferably from 3 x 10³ to 2 x 10⁵, and may be added in an amount of from
1/50 to 1/4, and more preferably from 1/40 to 1/10, in weight ratio, based on the
protective colloid (preferably gelatin) contained in the emulsion. The method to use
it may follow what has been described for the coagulating gelatin agent.
[0037] The emulsion according to the present invention may be obtained by preparing an emulsion
containing seed crystals and allowing grains to grow from the seed crystals. In the
instance where the seed crystals are used and the emulsion itself containing the seed
crystals is the emulsion according to the present invention in which the polymer coagulant
is used, all the emulsions obtainable therefrom fall under the emulsion according
to the present invention. However, a seed crystal emulsion for obtaining the emulsion
according to the present invention may not necessarily be the emulsion according to
the present invention. It is preferred that a seed crystal emulsion falling under
the emulsion according to the present invention is used as the seed crystals and at
the same time the emulsion according to the present invention, obtained by using the
polymer coagulant in the present invention, is used also when the grains are made
to grow therefrom.
[0038] The silver halides in the emulsion according to the present invention may be of any
composition, and usable silver halides include any silver halides as exemplified by
silver chloride, silver bromide, silver iodide, silver chlorobromide, silver iodobromide,
silver chloroiodide, silver chloroiodobromide and a mixture of any of these, but silver
iodobromide is particularly preferably used. In the instance where the silver iodobromide
is used, there is no particular limitation on the content of the silver iodide. However,
an average silver iodide content in the whole silver halide grains may preferably
be not more than 10 mol %, more preferably not more than 6 mol %, and still more preferably
from 0.2 to 6 mol %.
[0039] In this instance, the silver iodide may desirably be concentrated in the inside.
[0040] Preferable silver halide grains contained in the emulsion according to the present
invention may include silver halide grains having a multi-layer structure and plate-like
grains.
[0041] The plate-like grains can be obtained by adding a certain type of agent as exemplified
by thioethers in the course of the growth of grains. The plate-like grains are disclosed
in, for example, Japanese Patent Publications Open to Public Inspection (hereinafter
referred to as Japanese Patent O.P.I. Publications) No. 113927/1983, No. 113928/1983,
No. 105636/1984 (pages 252 to 253), and No. 147727/1985.
[0042] Here, the grains having a multi-layer structure refer to those provided on the outside
of a core with a shell having any desired halogen composition, and the so-called
core/shell grains can be used. The shell may comprise only one layer, or comprise
layers laminated in two or more layers, e.g., three or four layers, and preferably
not more than five layers.
[0043] Silver bromide, silver iodobromide or silver iodide may preferably be used as the
silver halide in the core and shell, but a mixture with a small amount of silver chloride
(specifically speaking, the one containing preferably about 10 mol % or less of silver
chloride, and more preferably about 5 mol % or less, of silver chloride) may also
be used.
[0044] It is preferred to use silver iodobromide grains in which the layer has been formed
by making different the silver iodide content.
[0045] It is also preferred that the outermost layer substantially consists of silver bromide
or substantially consists of silver iodobromide (10 % or less of silver iodide content),
and it may also contain a small amount (less than several %) of chlorine atoms.
[0046] The emulsion according to the present invention is prepared by forming silver halide
grains by adding an aqueous solution of a water-soluble silver salt and an aqueous
solution of a water-soluble halide in an aqueous solution containing a protective
colloid, and as a means for forming the silver halide grains here a variety of techniques
can be used.
[0047] For example, there can be used a simultaneous mixing method; a double jet method;
a method which is one form of the simultaneous mixing method, in which the pAg in
the liquid phase where silver halides are produced is kept constant, i.e., the so-called
controlled double jet method; and also a triple jet method as another form of the
double jet method, in which soluble halogen salts each having different composition
are independently added (as exemplified by soluble silver salts, soluble bromine salts
and soluble iodine salts).
[0048] It is also possible to use a regular mixing method, and still also possible to use
a method in which the grains are formed by use of excess silver ions (the so-called
reverse mixing method).
[0049] According to the controlled double jet method, it is possible to obtain a silver
halide emulsion comprising grains having a regular crystal form and an almost uniform
grain size.
[0050] To obtain the regular silver halide grains like this, reaction conditions may be
controlled when silver halide grains are made to grow by use of the simultaneous mixing
method, but, in such a simultaneous mixing method, it is possible to use a means of
preparing silver halide grains by adding an aqueous solution of a soluble silver salt
as exemplified by silver nitrate and an aqueous solution of a halide in substantially
equal amounts in an aqueous solution of a protective colloid with, in general, vigorous
stirring.
[0051] There are no particular limitations on the grain size of the silver halide grains,
but preferred grains are those having an average grain size of from 0.1 to 3 µm. More
preferred are those of from 0.3 to 2 µm.
[0052] The emulsion according to he present invention may be either a monodisperse emulsion
or a polydisperse emulsion, both of which can effectively exhibit the effect of the
present invention.
[0053] The emulsion according to the present invention can be chemically sensitized.
[0054] Besides, additives can be appropriately contained in the emulsion according to the
present invention or other emulsions optionally used to constitute the light-sensitive
material of the present invention.
[0055] More specifically, the light-sensitive material that embodies the present invention
may contain any desired additives, which are described in Research Disclosures Vol.
176, No. 17643 (December, 1978) and Vol. 187, No. 18716 (November, 1976). Corresponding
passages thereof are summarized in the following table.
[0056] Photographic additives that can be used in preparing the emulsion in working the
present invention described above are also described in the above two Research Disclosures.
The following table shows where they are described.

[0057] The amount of the gelatin used to constitute the light-sensitive silver halide photographic
material of the present invention may be arbitrarily selected, but the amount of gelatin
may more desirably be as small as possible in view of the rapid processing. For example,
the amount of gelatin per one side on the side having a light-sensitive emulsion layer
of an undeveloped light-sensitive material (in the case of the both-sided light-sensitive
material, the amount of gelatin when only one side is noted) may be controlled in
the range of from 2.0 to 3.5 g/m² to preferably work the invention.
[0058] The present invention, which can remarkably exhibit the effect particularly when
the amount of gelatin has been reduced so as to be adapted to rapid processing, can
be said to be feasible for the rapid processing.
[0059] The support for the light-sensitive material may be made of any desired materials.
[0060] In the developing solution used in the processing of the light-sensitive material,
a developing agent such as dihydroxybenzene as exemplified by hydroquinone, 3-pyrazolidones
as exemplified by 1-phenyl-3-pyrazolidone, aminophenols as exemplified by N-methyl-p-aminophenol
can be used alone or in combination.
[0061] Details thereof are described in L.F.A. Mason, Photographic Processing Chemistry,
Forcal Press, 1975 and Research Disclosures Vol. 188, No. 18873 (December, 1979) and
Vol. 204, No. 20405 (April, 1981).
EXAMPLES
[0062] Examples of the present invention will be described below in detail. As a matter
of course, the present invention is by no means limited by the following Examples.
Example 1
[0063] In the present Example, two types of seed crystals T-1 and T-2 were prepared in
the manner as shown below, and also prepared were Emulsion 1-1 (a comparative emulsion)
and Emulsion 1-2 (an emulsion according to the present invention), obtained by effecting
crystal growth from Seed Crystal T-1 (this seed crystal emulsion T-1 corresponds to
a comparative emulsion), and Emulsion 1-3 (an emulsion according to the present invention)
and Emulsion 1-4 (an emulsion according to the present invention), obtained by effecting
crystal growth from Seed Crystal T-2 (this seed crystal emulsion T-2 correspond to
an emulsion according to the present invention). Emulsion 1-5 (a comparative emulsion)
and Emulsion 1-6 (an emulsion according to the present invention), which are monodisperse
and do not use any seed crystals, were further obtained. Emulsion 1-7 (an emulsion
according to the present invention) and Emulsion 1-8 (a comparative emulsion), which
are polydisperse, were also obtained, and Emulsion 1-9 (a comparative emulsion) and
Emulsion 1-10 (an emulsion according to the present invention), containing plate-like
grains, were further obtained.
[0064] In describing below the present Example, descriptions are made by dividing them into
(i) preparation of emulsions (preparation of the above emulsions 1-1 to 1-10) and
(ii) preparation of and evaluation on samples (preparation of samples by use of the
above emulsions 1-1 to 1-10, and evaluation thereon based on the processing of the
samples and the results from various measurements).
(i) Preparation of emulsions:
(A) Preparation of Seed Crystals T-1 and T-2:
[0065] Monodisperse cubic grains of silver iodobromide containing 2 mol % of silver iodide
and having an average grain size of 0.3 µm were prepared according to a double jet
method while controlling the conditions to 60°C, pAg = 8 and pH = 2.0. A reaction
mixture containing the resulting grains was divided into two portions, which were
respectively subjected to the desalting as shown below to obtain two types of seed
crystals (T-1 and T-2).
Desalting for T-1:
[0066] While keeping the temperature at 40°C, added to the reaction mixture obtained after
the mixing was completed were 15 g/mol·AgX of a condensate (Compound I) of sodium
naphthalenesulfonate with formalin and 60 g/mol·AgX of magnesium sulfate MgSO₄, and
the resulting mixture was stirred for 3 minutes. The mixture was left to stand thereafter
to remove excess salts by decantation. Thereafter, 2.1 ℓ/mol·AgX of pure water of
40°C was added thereto to effect dispersion, followed by addition of 30 g/mol·AgX
of MgSO₄ and stirring for 3 minutes, and then the reaction mixture was left to stand
to carry out decantation. Thereafter, so called post gelatin was added, and the mixture
was kept to 55°C, stirred for 20 minutes and re-dispersed to obtain T-1.
Desalting of T-2 (corresponding to the means for removing dissolved matters to obtain
the emulsion according to the present invention):
[0067] While keeping the temperature at 40°C, added to the reaction mixture obtained after
the mixing was completed was 38 g of a modified gelatin of which 90 % of the amino
groups has been substituted by the exemplary group G-8 shown above, and the resulting
mixture was stirred for 3 minutes. Thereafter, 0.13 g/mol·AgX of potassium hydroxide
KOH was added thereto to control the pH to 4.0, and the mixture was left to stand
to carry out decantation. Thereafter, 2.1 ℓ/mol·AgX of pure water of 40°C was added
thereto, followed by addition of 0.25 g/mol·AgX of KOH to control the pH to 5.8, and
then stirring for 5 minutes. Thereafter, 1.5 cc/mol·AgX of nitric acid HNO₃ (1.7 N)
was added thereto to control the pH to 4.3, and the mixture was left to stand to carry
out decantation. Thereafter, post gelatin and 0.2 g/mol·AgX of KOH were added, and,
with the pH controlled to 5.8, the mixture was re-dispersed to obtain T-2.
[0068] This seed crystal emulsion T-2 is an emulsion according to the present invention,
and hence the emulsion obtained therefrom is the emulsion according to the present
invention.
(B) Growth from seed crystals:
[0069] Using the above Seed Crystals T-1 and T-2, the grains were made to grow in the following
manner: First, Seed Crystal T-1 was dissolved in 8.5 ℓ of an aqueous solution containing
a protective colloid and optionally ammonia (corresponding to the aqueous solution
containing a protective colloid), kept to 40°C, and the pH was adjusted by using acetic
acid. Using the resulting solution as a mother solution, an aqueous solution of 3.2
N ammoniacal silver ions as the aqueous solution of water-soluble silver salt was
added thereto according to a double jet method. Here, the pH and pAg were varied on
occasion depending on the silver iodide content and crystal habit. More specifically,
the pAg was controlled to 7.3, and the pH, to 9.7, thus forming a layer having a silver
iodide content of 35 mol %. Next, the pH was varied to between 8 and 9 and the pAg
was kept to 9.0 to make grains grow to the extent of about 95 % of the final grain
size. Thereafter, an aqueous potassium bromide solution as the aqueous solution of
a water-soluble halide was added over a period of 8 minutes through a nozzle, the
pAg was dropped to 11.0, and the mixing was completed 3 minutes after the addition
of the potassium bromide was completed. Next, the pH was dropped to 6.0 using acetic
acid. The resulting emulsion was comprised of monodisperse grains having an average
grain size of 0.53 µm and also having a silver iodide content of about 2 mol % in
the whole grains. Subsequently, the resulting reaction mixture is divided into two
portions, which were respectively subjected to removal of excess soluble salts (corresponding
to the removal of dissolved matters) according to the two types of methods for the
desalting methods (a) and (b) as shown below.
Desalting method (a):
[0070]
1. While keeping the temperature to 40°C, added to the reaction mixture obtained after
the mixing is completed are 5.5 g/mol·AgX of the previously mentioned Compound I (corresponding
to a comparative compound with respect to the polymer coagulant used in the present
invention) and 8.5 g/mol·AgX of MgSO₄, and the resulting mixture is stirred for 3
minutes, and then left to stand to carry out decantation.
2. After 1.8 ℓ/mol·AgX of pure water of 40°C is added to effect dispersion, 20 g/mol·AgX
of MgSO₄ is added, and thereafter the mixture is stirred for 3 minutes and then left
to stand to carry out decantation.
3. The step of the above 2. is repeated once more.
4. After 15 g/mol·AgX of post gelatin and water are added to make up the mixture to
450 cc/mol·AgX, the mixture is stirred at 55°C for 20 minutes to effect dispersion.
[0071] Emulsion 1-1 was obtained in this way.
Desalting method (b):
[0072]
1. While keeping the temperature to 40°C, added to the reaction mixture obtained after
the mixing is completed is 50 g/mol·AgX of a modified gelatin of which amino groups
have been substituted by the exemplary group G-8 shown above, followed by addition
of 110 cc/ of 56 wt.% acetic acid HAC to drop the pH to 5.0, and the resulting mixture
is left to stand to carry out decantation.
2. After 1.8 ℓ/mol·AgX of pure water of 40°C is added, 6.8 g/mol·AgX of KOH is added
to control the pH to 6.0, and dispersion is effected. After the dispersion was sufficiently
effected, 70 cc/mol·AgX of 56 wt.% HAC is added to control the pH to 4.5, and the
mixture is left to stand to carry out decantation.
3. The step of the above 2. is repeated once more.
4. Thereafter, 15 g/mol·AgX of post gelatin, 1 g/mol·AgX of KOH and water are added
to make up the mixture to 450 cc/mol·AgX.
[0073] Emulsion 1-2 was obtained in this way. The above desalting method (b) corresponds
to the means for removing dissolving matters to obtain the emulsion according to the
present invention.
[0074] In the same manner as above, grains were made to grow using Seed Crystal T-2, and
Emulsions 1-3 and 1-4 were obtained according to the above two types of desalting
methods.
(C) Preparation of Emulsions 1-5 and 1-6 by preparing monodisperse grains without
using any seed crystals:
[0075] In the same procedures as those for the seed crystals, i.e., under conditions of
60°C, pAg = 8 and pH = 2.0, an aqueous halogen salt solution and an aqueous silver
salt solution were added according to the controlled double jet method to obtain grains
having an average grain size of 0.53 µm and an average silver iodide content of 2
mol %. Emulsions containing such grains were desalted by the two types of methods
in the same manner as for the seed, thus obtaining Emulsion 1-5 (a comparative emulsion)
and Emulsion 1-6 (an emulsion according to the present invention).
(D) Preparation of polydisperse emulsions:
[0076] These were prepared using the following four types of solutions according to a regular
mixing method.
Solution A |
Silver nitrate |
100 g |
Ammonia water (28%) |
78 cc |
By adding water, made up to |
240 cc |
Solution B: |
Ossein gelatin |
8 g |
Potassium bromide KBr |
80 g |
Potassium iodide KI |
1.3 g |
By adding water, made up to |
550 cc |
Solution C: |
Ammonia water |
6 cc |
Glacial acetic acid |
10 cc |
Water |
34 cc |
Solution D: |
Glacial acetic acid |
226 cc |
By adding water, made up to |
400 cc |
[0077] Solution B and Solution C were poured into a reaction vessel for use in preparing
emulsions, which were stirred with a propeller type stirrer rotating at 300 rpm/min,
while keeping the reaction temperature at 55°C.
[0078] Next, Solution A was divided in the proportion of 1 part by volume : 2 parts by volume,
and 80 mℓ, corresponding to 1 part by volume among them, of the solution was poured
into the vessel taking a period of 1 minute. After stirring was continued for 10 minutes,
160 mℓ of the solution, corresponding to the remaining 2 parts by volume of Solution
A, was poured into the vessel taking a period of 10 minutes. Stirring was further
continued for 30 minutes. Then, Solution D was added and the pH of the solution in
the reaction vessel was controlled to 6.0, where the reaction was stopped.
[0079] Thereafter, desalting was carried out using the two types of desalting methods (a)
and (b), thus obtaining Emulsion 1-7 (a comparative emulsion and Emulsion 1-8 (an
emulsion according to the present invention), respectively.
(E) Preparation of plate-like grains:
[0080] In 1 ℓ of water, 10 cc of an aqueous 0.5 wt.% solution of thioether [HO(CH₂)₂S(CH₂)₂S(CH₂)₂S(CH₂)₂OH]
and 30 g of gelatin were added and dissolved, and the resulting solution was kept
to 70°C. In the solution, 30 mℓ of an aqueous 0.88 mol/ℓ solution of silver nitrate
and 30 mℓ of an aqueous 0.88 mol/ℓ solution of potassium iodide and potassium bromide
(in molar ratio of 3.5:96.5) were added with stirring according to a double jet method.
After addition of this mixed solution, the temperature was dropped to 40°C. Thereafter,
the solution was divided into two portions, to one of which 24.6 g/mol·AgX each of
Compound (I) and MgSO₄ was added, and the pH was dropped to 34.0 to carry out desalting,
followed by addition of 15 g/mol·AgX of post gelatin, thus preparing Emulsion 1-9
(a comparative emulsion). The other portion was also subjected to desalting according
to Steps 1 and 4 of the desalting method (b), thus obtaining Emulsion 1-10 (an emulsion
according to the present invention).
[0081] Emulsions 1-1 to 1-10 were obtained as in the above, where, in respect of the grains
in (A) to (E), the grains subjected to desalting by the means for obtaining the emulsion
according to the present invention showed better re-dispersibility in all instances.
(ii) Preparation of samples and evaluation thereon:
(ii-1) Preparation of samples:
[0082] The ten types of emulsions obtained in the above (i) were chemically sensitized.
More specifically, gold-sulfur sensitization was carried out by adding ammonium thiocyanate,
chloroauric acid and hypo.
[0083] After this chemical sensitization was completed, 4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene
was added. Thereafter, 150 mg/mol·AgX of potassium iodide, and 300 mg/mol·AgX and
15 mg/mol·AgX of spectral sensitizing dyes (1) and (2), respectively, were added to
carry out spectral sensitization.

[0084] The coating solutions and protective layer coating solutions thus obtained were coated
in layers on both sides of a polyester-film support having been subjected to subbing
treatment, in such a way that two layers are simultaneously coated in the order of
a silver halide emulsion layer and a protective layer from the support side, which
were thereafter dried to prepare silver halide photographic films.
[0085] To the above emulsion layers, the following additives were added per mol of silver
halide.

[0086] To the protective layers, the following compounds were added per 1 g of gelatin.

[0087] The following was used as a subbing solution.
(Subbing solution)
[0088] A copolymer comprising three types of monomers, comprising 50 wt.% of glycidyl methacrylate,
10 wt.% of methyl methacrylate and 40 wt.% of butyl methacrylate was diluted to give
its concentration of 10 wt.%, to obtain an aqueous copolymer dispersion, which was
used as a subbing solution.
[0089] The amount of gelatin of an undeveloped film used here was 3.10 g/m² per one side.
Samples 2-1 to 2-10 were thus obtained, corresponding to Emulsions 1-1 to 1-10 (See
Table 1).
(ii-2) Evaluation of samples (Processing and measurement of samples):
[0091] The following measurement and evaluation were made on the samples.
Sensitometry measurement:
[0092] Using as a light source the standard light B as described on page 39 of "SHINPEN
SHOMEI-NO-DETABUKKU (Data Book of Lighting, New Version)", edited by SHADANHOJIN SHOMEI
GAKKAI (Lighting Society Corporation), 1st Edition, 2nd Issue, all the samples 2-1
to 1-10 as shown in Table 1 were subjected to the so-called white exposure, wherein
non-filter exposure is carried out in an exposure time of 0.1 second and at 3.2 CMS
(candle meter second). Here, this exposure was made from both side of a film so as
to give the same amount of light on both sides of the film. The above samples were
processed with a development processing solution XD-90 (a product of Konica Corporation),
at 35°C for 90 seconds, using an automatic processor KX-800 manufactured by Konica
Corporation, to determine the speed of each sample.
[0093] The speed was obtained by finding a reciprocal of the amount of light which is necessary
for the blackening density to increase by 1.0 owing to the exposure. Provided that,
in Table 1, the speed is indicated as relative speed assuming the speed of Sample
2-1 as 100.
Evaluation on roller marks:
[0094] The pressure resistance in development processing (resistance to pressure marks,
i.e. roller marks, made by rollers of the automatic processor) was evaluated in the
following way: Samples, which were not exposed to light, were processed using an X-ray
automatic processor that comprises strongly uneven particular rollers comprising opposing
rollers and is capable of changing processing time in such a way that the processing
can be carried out in the processing time as shown below. Here, the processing was
carried out in three processing times: 3 minutes 30 seconds, 90 seconds, and 45 seconds.
As to the processing temperature, it was 32°C for the processing in 3 minutes 30 seconds,
35°C for the processing in 90 minutes, and 37°C for the processing in 45 minutes.
Results obtained are shown in Table 1.
[0095] Roller marks made at that time were evaluated by grouping into 5 ranks depending
on their degree.
5 No roller mark was made.
4 Roller marks were very slightly made.
3 They were slightly made (tolerable to practical use.
2 Many roller marks were made (intolerable to practical use).
1 Very many roller marks were made.
[0096] The developing solution and fixing solution used in the processing each had the composition
as shown below.
Developing solution :
[0097]

[0098] Made up to an aqueous 1 ℓ solution, and made to have the pH of 10.40 using potassium
hydroxide.
Fixing solution :
[0099]

[0100] Made up to an aqueous 1 ℓ solution, and made to have the pH of 4.3 using sulfuric
acid (50 wt.%)
Table 1
Sample NO. |
Emulsion NO. |
Speed |
Roller Marks |
The present invention or not |
|
|
|
Processed for |
|
|
|
|
3′30˝ |
90˝ |
45˝ |
|
2-1 |
1-1 |
100 |
1 |
1 |
2 |
No |
2-2 |
1-2 |
95 |
4 |
4 |
5 |
Yes |
2-3 |
1-3 |
100 |
3 |
4 |
4 |
Yes |
2-4 |
1-4 |
95 |
5 |
5 |
5 |
Yes |
2-5 |
1-5 |
90 |
1 |
1 |
2 |
No |
2-6 |
1-6 |
80 |
3 |
4 |
4 |
Yes |
2-7 |
1-7 |
80 |
1 |
1 |
2 |
No |
2-8 |
1-8 |
80 |
3 |
4 |
4 |
Yes |
2-9 |
1-9 |
100 |
2 |
2 |
2 |
No |
2-10 |
1-10 |
95 |
4 |
4 |
4 |
Yes |
[0101] As will be evident from Table 1, Samples Nos. 2-2 to 2-4, 2-6, 2-8 and 2-10, which
are the samples according to the present invention, all can be said to have good speed
and also good roller mark resistance, and have been improved in roller mark resistance
when they were subjected to rapid processing. The effect of the present invention
is also evident when samples containing grains of the same type are compared with
each other, namely, when Comparative Sample 2-1 and Samples 2-2 to 2-4 according to
the present invention are compared, and similarly when Sample 2-5 and Sample 2-6,
Sample 2-7 and Sample 2-8, and Sample 2-9 and Sample 2-10 are compared, respectively.
[0102] When the samples according to the present invention are compared with each other,
Sample 2-4 in which the means for obtaining the emulsion according to the present
invention has been employed in both the formation of seed crystals and the subsequent
grain growth shows slightly better roller mark resistance than Sample 2-3 in which
the same means has been employed only in respect of seed crystals. Other samples according
to the present invention are seen to be all good as a whole and be able to obtain
good results in any embodiments.
[0103] As described above, the present invention can provide a light-sensitive silver halide
photographic material that can be free of any deterioration of images as exemplified
by the deterioration of images owing to roller marks, can obtain an image of high
quality and also can be of high speed, even when fast processing is carried out.
1. A light-sensitive silver halide photographic material comprising a support and,
provided on at least one side thereof, a light-sensitive silver halide emulsion layer
containing a silver halide emulsion obtained by a method comprising the steps of
adding an aqueous solution of water-soluble silver salt and an aqueous solution of
a water soluble halide into an aqueous solution containing a protective colloid to
precipitate silver halide grains, and
coagulating said silver halide grains together with said protective colloid by the
use of a polymer coagulant, and removing a supernatant liquid containing dissolved
materials.
2. The light-sensitive silver halide photographic material of claim 1, wherein said
polymer coagulant is selected from the compounds represented by formula [I];

wherein R₁ and R₂ each represent an aliphatic group which may be the the same as
or different from each other; R₃ represents a hydrogen atom, an aliphatic group, an
aryl group or an aralkyl group; X represents - O - or - NH -; M⁺ represents a cation;
and n is an integer of 10 to 10⁴ ; provided that either one of two bonding arms in
chain B may be connected with the R₁- and R₂-bonded tertiary carbon atom in chain
A, and when X is - NH -, it may form a nitrogen-containing ring together with R₃.
3. The light-sensitive silver halide photographic material of claim 1, wherein said
polymer coagulant is a modified gelatin.
4. The light-sensitive silver halide photographic material of claim 3, wherein said
polymer coagulant is a gelatin of which amino groups have been substituted by a group
selected from an acyl group, a carbamoyl group, a sulfonyl group, a thiocarbamoyl
group, an alkyl group having 1 to 18 carbon atoms, and an aryl group.
5. The light-sensitive silver halide photographic material of claim 3, wherein said
polymer coagulant is a gelatin of which not less than 50 % of total amino groups contained
therein has been substituted.
6. The light-sensitive silver halide photographic material of claim 5, wherein said
polymer coagulant is a gelatin of which amino groups have been substituted by a group
selected from an acyl group represented by - COR¹ or a carbamoyl group represented
by by

wherein R¹ represents an aliphatic group, an aryl group or an aralkyl group, and
R² represents a hydrogen atom, an aliphatic group, an aryl group or an aralkyl group.
7. The light-sensitive silver halide photographic material of claim 6, wherein said
R¹ is an aryl group and R² is a hydrogen atom.
8. The light-sensitive silver halide photographic material of claim 5, wherein said
polymer coagulant is a gelatin of which amino groups have been substituted by a group
selected from the group consisting of G-1 to G-12;
9. The light-sensitive silver halide photographic material of claim 1, wherein said
protective colloid is either a gelatin or another hydrophilic protective colloid.
10. The light-sensitive silver halide photographic material of claim 3, wherein said
method further comprises a step of adjusting the pH of the solution after addition
of the modified gelatin.
11. The light-sensitive silver halide photographic material of claim 10, wherein said
pH is not more than 5.5.
12. The light-sensitive silver halide photographic material of claim 11, wherein said
pH is between 2 and 4.5.
13. The light-sensitive silver halide photographic material of claim 1, wherein said
silver halide grains essentially consist of a silver iodobromide containing silver
iodide at a proportion of not more than 10 mol %.
14. The light-sensitive silver halide photographic material of claim 13, wherein said
silver halide grain has higher silver iodide content in the inner portion thereof
than the outer portion.
15. The light-sensitive silver halide photographic material of claim 1, wherein said
water soluble silver salt is silver nitrate.
16. The light-sensitive silver halide photographic material of claim 1, wherein said
material is to be processed after imagewise exposure in an automatic depeloping processor
for a period of time ranging from 20 seconds to 3 minutes 30 seconds.
17. The light-sensitive silver halide photographic material of claim 16, wherein said
period is from 20 seconds to 90 seconds.
18. The light-sensitive silver halide photographic material of claim 17, wherein said
period is from 20 seconds to 60 seconds.
19. The light-sensitive silver halide photographic material of claim 1, wherein said
material comprises said light-sensitive silver halide emulsion layer on both sides
of the support.