JPH0561135A - Silver halide photographic sensitive material - Google Patents

Abstract

PURPOSE:To provide the silver halide photographic sensitive material resisting to both of sensitizing pressure and desensitizing as the pressure resistance of the photosensitive material without deteriorating a covering power. CONSTITUTION:The photographic sensitive material is coated with silver halide emulsion layers on both sides of a support and at least one of the emulsion layers is characterized by containing silver halide grains comprising those having an aspect ratio of <=5 and a grain thickness of >=0.25mum an amount of >=50% of the projection area of the total silver halide grains, and containing not more silver iodide in the layer located on the outside of the layers containing the 70mol% of the total silver halide grains than any of the inside layers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silver halide photographic light-sensitive material, and more particularly to a silver halide photographic light-sensitive material having improved pressure resistance without lowering sensitivity and covering power.

[0002]

BACKGROUND OF THE INVENTION In general, a photosensitive material is easily subjected to mechanical stress such as pulling or bending when it is loaded into a cassette, a camera or the like, including cutting and processing.

In particular, since sheet-shaped light-sensitive materials such as X-ray films and printing films are often handled directly by hand, there are many opportunities for pressure on the films.

When mechanical stress is applied to silver halide grains, pressure fog (also referred to as sensitized pressure due to a phenomenon in which a portion to which pressure is applied is blackened) or pressure desensitization (also referred to as desensitized pressure) may occur. Is well known.

Since such an unfavorable phenomenon also causes a misdiagnosis in the case of an X-ray film, prevention thereof is considered to be extremely important.

Conventionally, many techniques have been proposed as a method for preventing the sensitivity of a photographic light-sensitive material to external pressure. For example, JP-A-61-255337, which uses a binder component such as latex polymer, US Pat. U.S. Pat.No. 2,759,821 using a means for physically relaxing the external pressure applied to the silver halide grains, such as Japanese Patent No. 5,015,566, or using a compound such as an inhibitor or a photosensitive dye as an adsorbing compound for the silver halide grains. Japanese Patent Publication Nos. 51-95836 and 61-13583 are disclosed.

As an improved method from the side of silver halide grains, the core / shell type silver iodobromide grains having an aspect ratio of 5 or less have an average iodide content of 40 mol% or less,
Further, JP-A-60-147727 discloses that stress fog is prevented by chemically sensitizing the grains.

However, these prior arts cannot prevent both the above-mentioned sensitizing pressure and desensitizing pressure at the same time, and the sensitivity is greatly lowered, so that it cannot be improved to a practical level. The development of technology was strongly desired.

[0009]

SUMMARY OF THE INVENTION It is, therefore, a first object of the present invention to provide a silver halide photographic light-sensitive material which has improved pressure resistance of the light-sensitive material, and in which both sensitizing pressure and desensitizing pressure are prevented. .. Further, a second object of the present invention is to provide a silver halide photographic light-sensitive material capable of improving the covering power without lowering the sensitivity and simultaneously achieving the first object. Other objects will be apparent from the following specification.

[0010]

SUMMARY OF THE INVENTION These objects of the present invention have been achieved by the following finding. That is,
In a photographic light-sensitive material having at least one light-sensitive silver halide emulsion layer on each side of a support, at least one light-sensitive silver halide emulsion layer has at least 50% of the projected area of all silver halide grains. % Or more, the aspect ratio is less than 5, and the grain thickness is 0.25 μm or more.
It is achieved by a silver halide photographic light-sensitive material characterized in that a layer containing a silver iodide content higher than the silver iodide content of any layer outside 70% is not contained inside 70% of the silver amount of the whole grain. It

The present invention will be described in detail below. The silver halide photographic light-sensitive material of the present invention is characterized in that at least 50% or more of the projected area of all silver halide grains has an aspect ratio (ratio of grain size / grain thickness) of less than 5 and grain thickness of 0.25 μm or more. The aspect ratio is preferably 5 or less, more preferably 3 or less, and the particle thickness is 0.25 μm or more, more preferably 0.25 μm or more and 0.6 μm.
The following silver halide grains can be preferably used.

Incidentally, the so-called "2" in which the silver halide composition of the inner nucleus of the silver halide grain and its coating layer has been conventionally changed.
Silver halide grains having a multilayer structure of more than one layer are widely known.

For example, in a core / shell type silver iodobromide grain consisting of two layers (internal core and coating layer) having a uniform iodide distribution, the developability can be improved by making the average iodide contents of the two layers different. Technology such as increasing the sensitivity and measuring the sensitivity
-13162, JP-A-53-22408 or J. Photo.sci. 24, 198 (1
976) etc.

The silver halide grain in the present invention is a grain having a grain thickness of 0.25 μm or more and an aspect ratio of less than 5, as described above, and the silver halide grain is 70% of the total silver amount of the grain, preferably Is characterized in that no layer containing a silver iodide content higher than the silver iodide content of any layer outside 50%, more preferably 30%, is contained within 70% of the silver amount of the whole grain. is there.

The silver halide of the silver halide photographic light-sensitive material of the present invention may be silver iodobromide or silver iodochlorobromide containing a small amount of silver chloride. The silver halide grain may be of any crystal type as long as it has the constitution of the present invention, for example, it may be a single crystal grain such as an octahedron, a cube or a tetrahedron, and exhibits various shapes. It may be polytwinned grains.

The core / shell type silver halide grain of the present invention may be provided with a coating layer having an arbitrary halogen composition as a shell layer from 1 to 5 layers. The iodide content of the shell layer is 1 to
It is 40 mol% and preferably 1 to 20 mol%. The halogen composition of the core, which is the core of the grain, is 0-10
It has a difference in iodine content up to mol%, more preferably 0 to
That is, it has a difference of 5 mol%. The halogen composition of the inner core preferably has an iodine content of 0 to 5.0 mol%.
Silver iodobromide or silver bromide grains described above.

When the silver halide grain of the present invention comprises, for example, two or more layers, it is preferable that the outermost surface layer has a higher silver iodide composition than the inner nucleus.
In the case of more than one layer, the total iodide content of all layers of the coating layer reaching the innermost core from the outermost surface layer should be larger than the inner nuclei.

The average iodide content of the whole silver halide grains of the present invention may be 10 mol% or less, preferably 6 mol% or less. It is more preferably 3 mol% or less.

The silver halide grain size of the present invention is 0.2 to 1
0 μm, preferably 0.3-5 μm, more preferably
0.4 to 2.0 μm. However, the particle size referred to here is represented by the length of the side when converted to a cube of the same volume with the particle size obtained by the centrifugal sedimentation method. Further, the silver halide grains of the present invention are preferably so-called monodisperse with a narrow grain size distribution. The definition of monodispersity is described in JP-A-60-162244, and a preferable coefficient of variation of particle size is 5%.
~ 25%.

A method for producing a silver halide grain having a multilayer structure of two or more layers in which the silver halide composition of the inner nucleus of the silver halide grain and its coating layer is changed as in the present invention is widely known. U.S. Patents 2,592,250 and 3,505,068
No. 4,210,450, No. 4,444,877, JP-A-60-143331
No. and J.Phot.Sci. Can be referred to the method described in such as 24.198 (1976).

The emulsion used in the silver halide photographic light-sensitive material of the present invention can be produced by a known method. For example, Research Disclosure (RD) No.17643 (December 1978)
Mon) ・ Pages 22-23 1. Emulsion Preparati
on and types) and the same (RD) No.18716 (November 1979) ・
It can be prepared by the method described on page 648.

The emulsion of the silver halide photographic light-sensitive material according to the present invention is described, for example, in "The theory of the phot" by TH James.
"graphic process" 4th edition, published by Macmillan (1977) 3
The method described on pages 8 to 104, "Photographic Emulsion Chemistry" by GF Daufin, Focal pres
Published by P. Glafkides, “Physics and Chemistry of Photography“ Chimie et physique photographique ”Paul Montel
Published in 1967, VL Zelikman et al. "Making and Coating photographic Emulsio"
It is prepared by the method described in n ”Focal press (1964).

That is, the solution conditions such as the neutral method, the acidic method, the ammonia method, etc., the forward mixing method, the reverse mixing method, the double jet method, the controlled double jet method, etc., the conversion method, and the core / shell method. It can be produced using the particle preparation conditions such as and combinations of these.

The silver halide emulsion used in the present invention is
It is a tabular grain having an aspect ratio of less than 5.

The advantage of such tabular grains is that, for example, the spectral sensitization efficiency can be improved and the graininess and sharpness of images can be improved. For example, British Patent 2,112,157 and US Pat.
No. 20, 4,433,048, 4,414,310, 4,434,226
No. 58-113927, No. 58-127921, No. 63-138342
No. 63-284272, No. 63-305343, etc., and the emulsions can be prepared by the methods described in these publications. In these emulsions, a cadmium salt, a lead salt, a zinc salt, a thallium salt, an iridium salt or a complex salt thereof, a rhodium salt or a complex salt thereof, an iron salt or a complex salt thereof, or the like may be used in the stage of physical ripening or grain preparation. The emulsion may be subjected to a water washing method such as a Noudel water washing method or a flocculation sedimentation method in order to remove soluble salts. As a preferred washing method, for example, a method using an aromatic hydrocarbon aldehyde resin containing a sulfo group described in JP-B No. 35-16086, or G3, G8, etc., as an aggregation polymer agent described in JP-A No. 63-158644 is used. The method used is mentioned as a particularly preferable desalting method.

The emulsion according to the present invention can use various photographic additives in the steps before and after physical ripening or chemical ripening. Known additives include, for example, Research
Disclosure No.17643 (December 1978), No.187
16 (November, 1979) and No. 308119 (December, 1989). These three research
The following table shows the types of compounds and the locations where they are described in the disclosure.

Additive RD-17643 RD-18716 RD-308119 Page Classification Page Classification Page Classification Chemical sensitizer 23 III 648 Upper right 996 III Sensitizing dye 23 IV 648-649 996-8 IV Desensitizing dye 23 IV 998 B Dye 25-26 VIII 649-650 1003 VIII Development accelerator 29 XXI 648 Upper right fog inhibitor / stabilizer 24 IV 649 Upper right 1006-7 VI Whitening agent 24 V 998 V Hardener 26 X 651 Left 1004-5 X Surfactant Agent 26-7 XI 650 Right 1005-6 XI Antistatic agent 27 XII 650 Right 1006-7 XIII Plasticizer 27 XII 650 Right 1006 XII Sliding agent 27 XII Matting agent 28 XVI 650 Right 1008-9 XVI Binder 26 XXII 1003-4 IV support 28 XVII 1009 XVII Examples of the support that can be used in the light-sensitive material of the present invention include the above-mentioned RD-17643, page 28 and RD-308119, 100.
Examples include those described on page 9.

A suitable support is a plastic film or the like, and the surface of these supports may be subjected to undercoating, corona discharge, ultraviolet irradiation or the like in order to improve the adhesion of the coating layer.

[0029]

The present invention will be further described below with reference to examples, but the present invention is not limited to the examples described below.

Example 1 Highly monodisperse seed emulsions T-1, T-2 and T- were prepared by the following method.
3 was prepared.

(Preparation of T-1) A ₁ ossein gelatin 150 g Potassium bromide 60 g Water 1000 ml B ₁ Silver nitrate 1.5 kg Water 2000 ml C ₁ ossein gelatin 40 g Potassium bromide 1050 g Water 2000 ml D ₁ Ammonia water ( 28%) 710 ml To the A ₁ solution which was vigorously stirred at 40 ° C., the B ₁ solution and the C ₁ solution were added by the double jet method to generate nuclei. After the addition, the temperature of the mixed solution is lowered to 20 ° C., the potential is adjusted to 40 mv, and then D ₁
Was added in 20 seconds and aged for 5 minutes.

After that, the pH was adjusted to 6.0, and then desalting was performed using a formaldehyde resin of sodium naphthalenesulfonate and an aqueous magnesium sulfate solution. When this seed emulsion was observed with an electron microscope, it was a monodisperse silver bromide emulsion having an average grain size of 0.28 μm and a distribution of 30%. This emulsion was designated as seed emulsion T-1.

(Preparation of T-2) Seed emulsion T-2 was prepared in exactly the same manner as in the preparation of T-1, except that the following C ₂ solution was added in place of C ₁ solution in the preparation of T-1. Got

C ₂ ossein gelatin 40 g Potassium bromide 1000 g Potassium iodide 60 g Water 2000 ml This seed emulsion was observed with an electron microscope to find that the average grain size was
It was a monodisperse silver iodobromide emulsion having a silver iodide content of 0.28 μm and a distribution of 30% and a silver iodide content of 4 mol%.

(Preparation of T-3) Seed emulsion T-3 was prepared in exactly the same manner as in the preparation of T-1, except that the following C ₃ solution was added instead of C ₁ solution in the preparation of T-1. Got

C ₃ ossein gelatin 40 g Potassium bromide 950 g Potassium iodide 90 g Water 2000 ml This seed emulsion was observed with an electron microscope to find that the average grain size was
It was a monodisperse silver iodobromide emulsion having a silver iodide content of 8 mol% and a distribution of 30%.

Preparation of Tabular Grain Emulsion Using the seed emulsions (T-1, 2 and 3) described above and the following solutions, a silver halide emulsion (Em-
1, 2 and 3) were prepared.

E ₁ Hydrogen peroxide-treated ossein gelatin 37 g Polypropyleneoxy-polyethyleneoxy-di-succinate-disodium salt (10% methanol solution) 10 ml Equivalent to 1.14 mol of the above seed emulsion (T-1, 2 or 3) 4000 ml F ₁ hydrogen peroxide treated ossein gelatin 26 g potassium bromide 151 g potassium iodide 23 g water 1103 ml G ₁ hydrogen peroxide treated ossein gelatin 96.5 g potassium bromide 624 g water 4096 ml H ₁ silver nitrate 1132 g water the 6248Ml 75 above E ₁ solution was stirred vigorously at ° C., was added F ₁ solution and H ₁ solution by a double jet method. During this time, the pH was kept at 9.0 throughout.

After completion of the addition, the pH was adjusted to 6.0 and then 5,5'-di-chloro-9-ethyl-3,3'-di- (3
-Sulfopropyl) oxacarbocyanine sodium salt anhydride [sensitizing dye (A)] was added in an amount of 3 per mol of silver halide.
After adding 00 mg to allow sufficient adsorption, desalting was carried out in the same manner as in the above seed emulsion. The emulsion had a pAg of 8.5 and a pH at 40 ° C of 5.85. When the obtained emulsion was observed by an electron microscope, it was tabular silver halide grains having an average grain size of 0.85 μm and a distribution width of 20%, an aspect ratio of 2.4 and an average grain thickness of 0.35 μm.

Thus, Em-1 was prepared using the seed emulsion T-1, and E was prepared using the seed emulsion T-2.
Em-3 was prepared using m-2 and seed emulsion T-3.

Further, when grains are grown in the same manner as described above using seed emulsion T-1, they can be grown in the same manner as above except that the iodine content is increased to 4 mol% up to 50% of the finished grains. The obtained emulsion was designated as Em-4.

An emulsion prepared in the same manner as Em-2 except that seed grains T-2 was grown in the same manner as described above except that the iodide content was 6 mol%. Five
And

Preparation of Normal Crystal Grain Emulsion Iodobromide containing 2 mol% of silver iodide having an average grain size of 0.3 μm by the double jet method while maintaining the conditions of the reaction vessel at 60 ° C., pAg = 8, and pH = 2. A silver monodisperse cubic emulsion was obtained. According to the electron microscope observation, the generation rate of twins was other than 1% in number. This emulsion was used as a seed crystal and further grown as follows.

The gelatin aqueous solution was kept at 40 ° C. in the reaction vessel to disperse the seed crystals, and ammonia water and acetic acid were further added to adjust the pH =
Adjusted to 9.5.

After adjusting the pAg to 7.3 with an ammoniacal silver ion solution, a solution containing ammoniacal silver ions, potassium iodide and potassium bromide was added by the double jet method while keeping the pH and pAg constant, and the iodide was added. A silver iodobromide layer containing 30 mol% of silver was formed.

The pH was adjusted to 9 and pAg = 9.0 using acetic acid and silver bromide, and then an ammoniacal silver ion solution and potassium bromide were added at the same time, and grown to 90% of the grain size after growth. At this time, the pH was gradually lowered from 9.0 to 8.20.

After adding potassium bromide solution to pAg = 11, ammoniacal silver ion solution and potassium bromide were further added to grow while gradually lowering pH to an average particle size of 1.23 μm.
A silver iodobromide emulsion containing m and 2 mol% of silver iodide was obtained.

When the emulsion is prepared, the sensitizing dye (A) is used.
200 mg per mol of silver was added to the emulsion to obtain an emulsion.

Next, as shown below, a desalting step for removing excess salt was performed.

The silver halide emulsion solution was kept at 40 ° C., a formalin condensate of sodium naphthalenesulfonate was added to precipitate silver halide grains, and the supernatant was discharged, and then pure water at 40 ° C. was added. Then, magnesium sulfate is added to again settle the silver halide grains, and the supernatant is taken. Do this again, add gelatin, pH 6.0, pAg 8.
An emulsion of 5 was obtained. This emulsion was designated as Em-A.

Further, the amount of seed emulsion was adjusted to obtain Em-B having an average particle size of 0.4 μm by the same method as for Em-A.

The emulsions Em-1, 2, 3, 4, 5 and A, B of the resulting emulsion were each used as a spectral sensitizing dye immediately before the addition of the chemical sensitizer consisting of hypo and chloroauric acid. 150 mg of (A)
And 5,5'-Di- (butoxycarbonyl) -1,1'-diethyl-3,3'-di- (4-sulfobutyl) benzimidazolocarbocyanine sodium salt anhydride [sensitizing dye (B)]. Is chemically ripened by adding 15 mg per mol of silver halide, and then potassium iodide is added by 300 mg per mol of silver halide,
Stopped chemical ripening. Further, 2.5 g of 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene was added as a stabilizer per mol of silver halide.

The emulsions that had been chemically ripened were mixed as shown in Table 1 below, and then the following various additives were added to prepare coating solutions.

[0054]

[Table 1]

To the above emulsions 1 to 5, as an additive, per mol of silver halide, t-butyl-catechol 400 mg styrene maleic anhydride copolymer 2.5 g nitrophenyl-triphenylphosphonium chloride 50 mg 1,3 -Ammonium dihydroxybenzene-4-sulfonate
4 g nC ₄ H ₉ OCH ₂ CH (OH) CH ₂ N (CH ₂ COOH) ₂
1g 1,1-dimethylol-1-bromo-1-nitromethane 20mg

[0056]

[Chemical 1]

The ingredients described above were added to prepare an emulsion coating solution.

Further, as a protective layer liquid, the following amounts of additives were added per 1 g of gelatin to prepare a protective layer coating liquid.

Matting agent composed of polymethylmethacrylate having an average particle size of 7 μm 40 mg Colloidal silica having an average particle size of 0.013 μm 70 mg Glyoxal 25 m
g

[0060]

[Chemical 2]

The above coating solution was uniformly coated on both surfaces of a blue-colored polyethylene terephthalate film base as an undercoating agent having a thickness of 180 μm and dried to give Samples 1 to 5 as shown in Table 2. Created. That is, the emulsion layer had a single-sided gelatin amount of 3.2 g / m ² so that the single-sided silver amount was 3.2 g / m ^2.
The protective layers were simultaneously coated on both sides so as to have 0.98 / m ² .

(Evaluation of Sensitivity) The obtained sample was sandwiched with an intensifying screen for X-ray photography, KO-250, and X-rayed through a penetrometer B type.
After irradiation with X-ray, it was processed with XD-SR development processing solution for 45 seconds at 35 ° C using the SRX-501 automatic developing machine (both Konica Corporation).
Made).

The sensitivity of each sample developed as described above was evaluated. The sensitivity was shown as a relative value with the reciprocal of the amount of bombardment energy required for Sample 1 to give a density of fog +1.0 as 100.

(Evaluation of Durability) The obtained sample was heated at a temperature of 25.
It was kept at a constant temperature and humidity of 50 ° C. and RH of 50%, and under this condition, it was bent at a radius of curvature of 2 cm by about 280 °.

After 3 minutes from bending, uniform exposure was performed so that the density became about 1.0, and then development was performed in the same manner as in the sensitivity evaluation.

The ratio D '/ D between the density D'of the desensitized portion caused by bending after development and the density D'of the portion not bent is calculated, and the smaller the value, the desensitizing pressure (pressure desensitization resistance). ) Indicates that it is bad.

The results obtained are shown in Table 2 below. As can be seen from the table, the samples of the present invention have improved desensitizing pressure.

This desensitizing pressure is a very unfavorable phenomenon in the case of a medical film because it is difficult to distinguish it from a lesion in terms of diagnosis, and a level of 0.95 or less is usually a problematic value in the market.

[0069]

[Table 2]

Example 2 When preparing Em-1 in Example 1, Em-1 of Example 1 was prepared except that the potential and flow rate of the reaction vessel when growing grains from the seed emulsion T-1 were adjusted. The particles having the particle thickness and the aspect ratio shown in Table 3 below were prepared in exactly the same manner.

The obtained emulsion was chemically ripened in the same manner as Em-1 and coated similarly to prepare a sample. CP (covering power) in the table is shown as a relative value in which the blackening density / silvering black amount is represented by setting the sample No. 1 of Example 1 as 100.

The sensitizing pressure indicated the blackening density value of the bent portion according to the method of Example 1. Practically, this density is a failure on the film due to a fold or the like when the film is handled, and if the density value is 0.5 or more at the level evaluated this time, it is a problem in the market and is not preferable.

The results obtained are shown in Table 3 below.

[0074]

[Table 3]

As is clear from Table 3, the sample having a high aspect ratio and a small particle thickness has a slightly increased CP, but the pressure resistance (sensitizing pressure) is greatly deteriorated and is not suitable for practical use. In the sample according to the invention, both CP and sensitizing pressure are improved.

[0076]

According to the present invention, a silver halide photographic light-sensitive material having improved pressure resistance against both sensitizing pressure and desensitizing pressure can be obtained without deteriorating the covering power.

Claims (1)

[Claims] 1. At least one on each side of the support.
In a photographic light-sensitive material having two layers of light-sensitive silver halide emulsion layers, at least one of the light-sensitive silver halide emulsion layers has an aspect ratio of less than 5 at least 50% or more of the projected area of all silver halide grains. , A layer having a grain thickness of 0.25 μm or more, and the silver halide grain is a layer containing a silver iodide content greater than the silver iodide content of any layer outside 70% of the total silver content of the grain. A silver halide photographic light-sensitive material characterized by containing no more than 70% of the total amount of silver in the grain.