JPS61116346A - Silver halide photosensitive material - Google Patents

Abstract

PURPOSE:To enbroaden an exposure latitude of the titled material at a low temp. and a high concentration by incorporating at least one of compds. shown by the specific formulas to at least one of emulsion layers provided on a substrate. CONSTITUTION:The prescribed specific compd. comprises the compds. shown by formula I wherein R1, R2 and R3 are an alkyl or an alkenyl group, X<->1 is an anion, Z1 and Z2 are a nonmetallic element necessary to form a benzene ring, the compd. shown by formula II wherein R4 and R5 are each an alkyl group, R6 is a hydrogen atom or a lower alkyl group, X<->2 is an anion, Z1 and Z2 are each a nonmetallic atom, and the compd. shown in formula III wherein R7 and R9 are each an alkyl group, R8 and R10 are each a lower alkyl group, X<->3 is an anion, Z1 and Z2 are each a nonmetallic atom necessary to form a benzene ring.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a silver halide photographic material for X-rays. This type of photosensitive material is used for various diagnostic purposes in the medical field, as part of X-ray deep wound technology in the industrial field, and for tracing radioactive isotopes in fields such as bioengineering. It is widely used.

[Conventional technology]

X-ray silver halide photographic light-sensitive materials (some have a photosensitive emulsion layer on both sides of the support and others have a photosensitive emulsion layer on only one side; hereinafter, both types will be referred to simply as "X-ray sensitive"). ) is required to have high sharpness, large amount of information, good graininess, resistance to pressure desensitization (desensitization due to tab pressure), and little deterioration of image quality. Ru.

For example, regarding medical X-ray sensitive materials, they have high sharpness,
The better the granularity, the easier it is to diagnose, and the greater the amount of information, the higher the diagnostic ability, which is advantageous6).In addition, there is less pressure desensitization, information is reliably visualized, and the image quality does not deteriorate and storage stability is improved. Good things are desired.

In this way, when taking X-ray photographs of various parts of the body in the medical field, in order to detect lesions early and prevent misdiagnosis,
It is required that the image quality be sharp, that is, 6, that there is a large amount of information, and that the diagnostic ability is high, but conventional X-ray sensitive materials are still not always satisfactory.

That is, in the characteristic curve of FIG. 1, the conventional direct X-ray sensitive material has a high gamma type indicated by (&), a low gamma type indicated by Φ),
It is broadly classified into the moderate type shown in (C). However, high gamma type (
&) has a high sharpness because the characteristic curve rises steeply as shown in the figure, but the amount of information in the low exposure portion is poor. On the other hand, the low gamma type (b) can be conveniently used in the form of (b') in which the dose is f: il1 and the curve is moved in parallel to the left side of the figure, and in this case, the photographic density in the low exposure area can be increased. Therefore, the amount of information in the low exposure area is rich, but the slope of the characteristic curve is gentle and the sharpness is low, making diagnosis difficult. Furthermore, the medium type (e) has only a medium sharpness and a medium amount of information in low density areas.

“For each type of direct X-ray sensitive material, the gamma at each density is typically as shown in Table 1 below. Each gamma shown in the table is based on the optical density (b) and In a characteristic curve on a rectangular coordinate system with the same unit length of the coordinate axes of exposure (log E), the optical density is the same as 0.050 point.
．． Let the gamma created by the 30 points be Gan 11 (it), and the gamma created by the optical density 0.500 point and the same 1.500 point be Ga/
72 (r2), and the gamma between the optical density of 2.00 and 3.00 is defined as gamma-f3 (γ5).

Table 1 However, in actual examples of X-ray photography using these conventional type direct X-ray sensitive materials, the following major problems occur. In other words, the body parts most commonly photographed using XLS in Japan are the chest, stomach, and bones of the limbs, but with the conventional X-ray sensitive materials mentioned above, it is not always possible to obtain satisfactory images for all of these parts. has not been achieved.

First of all, regarding the chest, the important parts when interpreting a chest photograph are the blood vessels in the lung area and the coronary arteries behind the heart.

The lung field is in the moderate concentration region (O = t, a ~ 1.5),
High sharpness is required to interpret the blood vessels inside.
At the same time, the coronary artery is a low concentration area (D = 0.05-0.30)
A wide latitude is required. Finally, it is required that the exposure latitude is wide and sufficient information can be obtained as an image. However, with conventional high-gamma X-ray sensitive materials, although the lung field has high sharpness, the coronary arteries are depicted only at very low density, and cannot substantially contribute to diagnosis. Conversely, when a low gamma type X-ray sensitive material was used, the coronary arteries were depicted, but the sharpness of the lung field was low.

Next is X-ray photography of the stomach, but since a contrast agent is used to enhance the descriptive power in this X-ray photography, conventional high-gamma type X#I photosensitive materials for direct use reduce the amount of exposure to the contrast agent area. When combined, only a completely black image was obtained after development of the area without the contrast agent, which could not contribute to diagnosis in any way. In order to avoid this phenomenon, low-gamma-type direct X-ray sensitive materials are often used; however, in the case of this X-ray sensitive material,
Since the sharpness decreases, the diagnostic ability of the gastric wall region containing the contrast agent decreases.

Next, imaging of bone tissue and soft tissue (internal or cartilage) of hands and legs, etc. In this case, conventional high-gamma X
Although the fine structure of bone scars was highly sharp with the line-sensitive material, the soft tissue was crushed to a pitch black color and could not contribute to diagnosis. Conversely, when a low gamma type X-ray sensitive material was used, soft tissue was depicted, but the sharpness of bone tissue was low.

In addition, in various photosensitive materials, pressure desensitization (desensitization observed during development due to mechanical pressure before exposure) may occur due to various mechanical pressures applied before exposure. also has this problem. In particular, medical X-ray film is large in size, so it may bend under its own weight from the supported part, or the film may bend, such as so-called claw folding, which is more likely to cause pressure desensitization. In addition, automatic exposure and developing devices using mechanical conveyance are now widely used as medical X-ray photography systems, but in these devices, mechanical force is applied to the film, especially when it is dry during the winter. However, the aforementioned pressure blackening and pressure desensitization are likely to occur. Such a phenomenon may cause serious problems in medical diagnosis.

It is well known that pressure desensitization is particularly likely to occur in photographic materials containing highly sensitive silver halide grains with large grain sizes.

US Pat. Nos. 2,628,167, 2,759,822, and 3 are aimed at improving pressure desensitization.
, No. 445,235, No. 2,296,204 and French Patent No. 2,296,204, Japanese Patent Application Laid-Open No. 1983-107
No. 129 and No. 50-116025, etc., describe methods using thallium or dyes, but the degree of improvement is insufficient, dye staining is severe, and other methods are not always suitable. It cannot be said that this material fully brings out the qualities of a silver halide photosensitive material that mainly utilizes the high sensitivity and normal surface sensitivity of the halide grains having a large average particle size.

On the other hand, various attempts have been made to improve pressure desensitization by changing the physical properties of the binder of silver halide photographic materials. For example, U.S. Patent Nos. 3,536,491 and 3,775,1
No. 28, No. 3,003,878, No. 2゜759.82
No. 1 and No. 3,772,032, as well as JP-A-53-
No. 3325, No. 50-56227, No. 50-1473
No. 24 and No. 51-141625. However, even if these techniques improve pressure desensitization, the physical properties of the binder such as stickiness, dryness, and scratches on the film surface are significantly deteriorated and cannot be fundamentally improved.

On the other hand, in recent years, with the development of photographic technology, there has been a strong desire for higher sensitivity of silver halide photographic materials, and in the field of medical X-ray photography, there has been a shift from the regular type, which had a sensitivity of 1 wavelength at 450 nm, to , further ortho-sensitized, 54
Orthotype photosensitive materials that are sensitive to a wavelength range of 0 to 550 nm have come into use. Those sensitized in this way have a wider photosensitive wavelength range and a higher sensitivity9, and therefore can reduce the amount of X-rays that they are exposed to and the effect they have on the human body.

Therefore, for example, the sensitivity can be increased by the above-mentioned sensitizing means, and good images can be obtained even for the above-mentioned areas, and the X-ray sensitivity is improved in pressure desensitization. Currently, there is a need for the development of new materials.

[Objective of the Invention] The object of the present invention is to provide high sharpness and wide exposure latitude in low-density areas and high-density areas, thereby improving diagnostic ability when used for medical purposes, and reducing graininess. Good, pressure desensitization <<, less deterioration of image quality, advantageous X
The purpose of the present invention is to provide line-sensitive materials.

[Structure and operation of the invention]

The X-ray sensitive material related to house ruins has an optical density ρ) and an exposure amount (l
In the characteristic curve on the rectangular coordinate system with the same coordinate axis unit length of og B), the gaff ff(r+) created by the point of optical density 0.05 and the point of optical density 0.30 is 0.36 to 0.65. , and the gamma (γ2) created by the points i and so, which are the same as the optical density 0.500 point, is 2.7 to 3.3, and the optical density is 2. O
Same as O 3. Gamma (γ5) between OO and OO is 1.5 to 2.
It is characterized by being 5.

By adopting this configuration, the X-ray sensitive material of the present invention can achieve the above-mentioned object. In the present invention, each of these configurations works together to achieve the above object, but roughly speaking, by setting rl in the above range, the exposure latitude in the low density area can be widened. It can be said that by setting 12 in the above range, the sharpness is improved, and by setting r5 in the above range, the exposure latitude in the high density area can be widened. This configuration also improves graininess and
Prevention of pressure reduction and image quality deterioration is achieved.

When carrying out the present invention, preferably, in the characteristic curve on the rectangular coordinate system when processed under the following processing conditions, the rl is 0.36 to 0.65, and γ2 is 2.7 to 2.7.
3.3, and a characteristic curve with r5 of 1.5 to 2.5 is obtained.

[Processing conditions]

Processing is carried out using a roller conveyance type automatic developing machine according to the following steps using the following developer solution-1.

Processing temperature Processing time Developer-1 However, among the above conditions, the processing temperature, processing time, amount of developing agent, etc. may vary somewhat.

The characteristic curve referred to in the present invention is obtained by, for example, the following optical sensitometry CAI. That is, in this photosensitometric CAI, exposure is carried out by sandwiching an X-ray sensitive material having a photosensitive emulsion layer on both sides (or one side) of a transparent support between two optical wedges whose density gradients are mirror-symmetrically aligned. and then exposed to a light source with a color temperature of 5.400' for 1/10 seconds from both sides simultaneously and equally. The processing is carried out using a roller conveyance type automatic developing machine according to the above-mentioned steps.

The fixer is not particularly limited as long as it is an acidic hardening fixer, such as Sakura It is determined based on a characteristic curve plotted on a rectangular coordinate system in which the unit length of the coordinate axes is set equal. Said γ
1 is the density point on the characteristic curve of the base (support) concentration factor Capri density + 0.05 and the point of the base concentration factor Capri density + 0.
．． r2 means the slope of the straight line connecting the points with a density of 30, and the above r2 is the slope of the straight line connecting the point with a base density of Capri density of 0.500 and the point of the base density with Capri density + 1.500 density. In addition, r5 means the slope of the straight line connecting the point at the density of pace concentration sub-capri density +2.00 and the point at the density of pace density sub-capri density +3.00. To further express it numerically, the angle at which these straight lines intersect with the exposure axis (horizontal axis) is 01. θ2 and θ), rl and γ2 mean tanθ1, tJLnθ2 and tLnθ, respectively.

The method of obtaining the characteristic curve of the present invention is arbitrary, and may include the use of monodisperse emulsions, polydisperse emulsions, core-shell type monodisperse emulsions, core-shell type polydisperse emulsions alone or in combination of two or more, particle size or Any technique such as controlling the particle size distribution, optimizing the silver halide crystal habit, adjusting the hardness, adding a development accelerator, or adding a development inhibitor may be used.

In a preferred embodiment of the present invention, nine particles obtained by any of the above-mentioned methods are obtained by using at least one compound selected from the group of compounds represented by the following general formula (I) CIII and saliva. The above characteristic curve of the present invention is obtained by dye sensitization. In this case, this is preferably achieved by a combination of two or more types of monodisperse particles or polydisperse particles. Alternatively, these particles may be chemically sensitized; in that case, the optimum chemical sensitization may be performed separately for each particle, or the two may be mixed and then chemically sensitized.

For implementation of the present invention, the former is rather preferred.

In this way, if an embodiment using any of the compounds of the general formula CI](III [1) is adopted, ortho-sensitization is carried out, and further improvements are made particularly in terms of graininess and pressure desensitization. In other words, regular type Because large particles were used for the legs, which required high sensitivity, the graininess and pressure desensitization performance were poor.However, in such orthotypes, the sensitivity is increased by dye sensitization, so the halogenation used is Silver particles can be made smaller. As a result, graininess and pressure desensitization performance can be further improved.

General formula CI) ([1(I[I] is as shown below.

[General formula % formula %] [In the formula, "1", R2, and R each represent a substituted or unsubstituted alkyl group, alkenyl group, or aryl group, and at least one of R1 and R is a sulfoalkyl group or a carboxy Alkyl group is used. Xi is an anion, z
1 and z2 represent a group of nonmetallic atoms necessary to complete a substituted or unsubstituted benzene ring, and n represents 1 or 2. (
However, when forming an inner salt, n is l. )] [■] (X;)n-0 [In the formula, R,, R, each represents a substituted or unsubstituted alkyl group, alkenyl group, or aryl group, and at least one of R4 and R5 is sulfoalkyl or carboxyalkyl group. R6 represents a hydrogen atom, a low alkali group, or an alkyl group.

Xi represents an anion, 2□ and a group of nonmetallic atoms necessary to complete the z2-rod-substituted or unsubstituted benzene ring, and n represents 1 or 2t-. (However, when forming an inner salt, n is 1.)] aD (Xl)n-1 [In the formula, R7 and R9 are each substituted or unsubstituted lower alkyl group, Rg and RIO are lower alkyl group, hydroxyalkyl group, sulfoalkyl group, carboxyalkyl group; Xl is an anion; zl and z2 are nonmetallic atomic groups necessary to complete a substituted or unsubstituted benzene ring; (However, when forming an inner salt, the swelling is l.)] The emulsion forming the X-ray sensitive material of the present invention has the general formula CII
) When using the compound (III), it is preferable that at least 95% of the weight or number of silver halide grains contained in the silver halide emulsion have a grain size within ±4C1 of the average grain size. .

Next, the compound of formula CII (I[] rule) will be further explained.

In general formula CII, the substituted or unsubstituted alkyl group of R1#"2 pR5 can specifically include, for example, a lower alkyl group such as methyl, ethyl, n-propyl or butyl. al +RZ tB5
Examples of substituted alkyl groups include vinylmethyl, hydroxyalkyl groups include 2-hydroxyethyl, 4-hydroxybutyl, etc., and acetodialkyl groups include 2-ace14 dibutyl, 3-ace14
Dibutyl etc., carboxyl alkyl group such as 2-carboxyethyl, 3-carboxypropyl, 2-(2-carboxyethyl)ethyl etc., sulfoalkyl group 2-
Examples include sulfoethyl, 3-sulfopropyl, 3-sulfobutyl, 4-sulfobutyl, 2-hydroxy-3-sulfopropyl, and the like. Examples of the alkenyl group for R1°R2,J include allyl, butynyl, octenyl, and oleyl. Furthermore, examples of the aryl group of R1tR2tR5 include phenyl, carboxyphenyl, and the like. However, as a general rule, at least one of R1sR2eR5 is a sulfoalkyl group or a carboxynealkyl group.

Examples of the anion represented by xl in formula [I] include chloride ion, bromide ion, iodide ion, thiocyanate/acid ion, sulfate ion, perchlorate ion, p-
Examples include toluenesulfonate ion, ethylsulfate ion, and the like.

Next, typical examples of the compound represented by the general formula CII will be given, but the present invention is not limited thereto.

(Compound example) 3”ゝ., H5(2)
. t HS fortune H□CHt COO
HCH! CH*OCH CHISO! -(6)
C*H5(
7) CJs
(C'Hx) OCOCHs (1G) Cx Hs(1
1) CgHs'12)
. t)la(13)
CwHs (14)
. 3H3 (16)
. □, 0H8°. H8゜□,
. □Cx Hs C*Hs (CH spirit) #SO!
-shii3 (21). gHsl CHs (CHJ#5Ch-Cm
Hs (23). l HS■ (2") .aHqMaHq
(CHs)*5Os-CtHs (CHJsSOsH(CHt)sS()+-C*Hs (CHs)ySOx-CtHs C-toH is also C, H% (CHm)sS Os-CtHs CtHs (CHs)sSCh-CtHs Ct Hs ■ CtHs (CHz)sSO
ff-CtHs (3 days) CtHs CtHs ■ CtHs ■ In formula [11], R6 represents a hydrogen atom, a lower alkyl group, or an aryl group, and as a lower alkyl group, groups such as methyl, ethyl, propyl, butyl, etc. can be mentioned,
Examples of the aryl group include those exemplified as R+ and R3 in A21. Examples of the anion of Xl include those exemplified as Xτ in formula [I].

Next, typical specific examples of the compound represented by the formula [II] will be given, but of course, in this case as well, based on this example (AA1
The present invention is not limited.

[Yes] To A 1 CH heavy CHzSOsHCHzCHtSOs(CHt)s
SChNa (CHz)ssOs-C
tHs (CHz)ss
OsCHICHtCHxSOsHCHtCH*CHtS
Os Next, in the formula circle, examples of lower alkyl groups for R7 and R9 include methyl, ethyl, propyl, butyl and the like. Examples of substituted alkyl groups include the groups exemplified for R1 to R5 in formula [I].

Examples of the lower alkyl group in 8e RIO include the same groups as Rτ and R. Examples of the hydroxyalkyl group, sulfoalkyl group, and carboxyalkyl group in R85RIG include the groups exemplified for R1 to R5 in formula CII. I can do it.

Examples of the anion of X3- include those exemplified as Xl- in the formula.

Typical specific examples of compounds represented by the formula (2) are listed below. Of course, the present invention is not limited to this example either.

(Compound example) C2H5(CH2)IISO5- The total amount of the compound represented by the above formula CI) [:II] (8) is 101 NI to 90 NI per mol of silver halide.
It can be used in the 0wpo range. Special 1c, 60-6
0011Q is preferred.

Chemical sensitization methods applied to grown particles include, for example, sulfur sensitization methods using sodium thionitrate, thiourea compounds, etc., gold sensitization methods using chloroaurates, gold trichloride, etc., divalent thiourea, There are reduction sensitization methods using stannous chloride, silver ripening, etc., palladium sensitization methods, selenium sensitization methods, etc., and these methods can be used alone or in combination of two or more. In this case, it is particularly preferable to use gold sensitization and sulfur sensitization together.

In the practice of the present invention, silver halide grains in the I-logonide emulsion may have an average grain size of 0.3 to 3 .mu.m.

Inside such silver halide grains, there are at least two
It is preferable that a localized portion in which silver iodide is localized at a high concentration of 0 molti or more is present.

In this case, the inside of the particle is preferably located as far inward as possible from the outer surface of the particle, particularly within 0.000 m from the outer surface. O
It is preferable that the localized portion exists at a distance of IAm or more.

Further, the localized portion may exist in a layered manner inside the particle, or may have a so-called core-shell structure, with the entire core serving as the localized portion. In this case, it is preferable that part or all of the grain core part excluding the shell part having a thickness of 0.01 μm or more from the outer surface is a localized part with a silver iodide concentration of 20 molti or more.

In addition, the concentration of silver iodide in the localized portion is 30 to 40
The molar ratio is preferably within the range.

In the practice of the present invention, the silver halide grains used in the silver halide emulsion are described, for example, by T. H. James @The Th@ory of the Photog
rapic Process' 4th edition, Macm11
Neutral method, acidic method, ammonia method, forward mixing, etc. described in literature such as 1ansha (1977) pp. 88-104,
Back mixing, double jet method, chondral double jet method, convourage:! It can be manufactured by applying a method such as a core/shell method or a core/shell method. Silver halide compositions include silver chloride, silver bromide, silver chlorobromide, silver iodobromide,
The most preferred emulsions are silver iodobromide emulsions containing less than about 10 moles of silver iodide, although any silver chloroiodobromide emulsion can be used.

There are no particular restrictions on the grain size of silver halide grains, but
Preferably 0.1 to 3μ, more preferably 0.3μ
~2μ. Further, these silver halide grains or silver halide emulsions are coated with iridium salt and/or silver halide containing no R4° silver in order to improve flash exposure characteristics.

That is, in a preferred embodiment, the distance from the outer surface is 0.0
The shell portion with a thickness of IJjrn or more, especially from 0.01 to 1.5 Am, is made of silver iodide-free silver halide (usually silver bromide).

In the present invention, from the inside of the particle (preferably from the outer wall of the particle)
, inside the particles separated by at least oi μm).
As a method for forming localized portions of high concentration silver iodide with a molar ratio of 0 or more, it is preferable to use seed crystals, but methods that do not use seed crystals may also be used.

If seed crystals are not used, the reaction liquid phase containing the protected gelatin (
Since there is no silver halide that can serve as growth nuclei in the mother liquor (hereinafter referred to as mother liquor) before the start of ripening, first, silver ions and halide ions containing high concentration iodine ions of at least 20 molti are supplied to form growth nuclei. let Then, additional supply is continued to grow particles from the growth nuclei.

Finally, add 0.01μ of silver halide that does not contain silver iodide.
A shell layer having a thickness of m or more is formed.

When using seed crystals, at least 20 mol of silver iodide may be formed only on the seed crystals, and then covered with a shell layer. Alternatively, the amount of silver iodide in the seed crystal is O or 10
within the range of less than molt, and at least 20 molt of silver iodide is formed inside the grains in the step of growing seed crystals,
This may be followed by coating with a shell layer.

In this case, in the present invention, the ratio of silver iodide to the total silver halide in the entire grain is within the range of 0.5 to 10 to 13, which is within the range of 1-1. In comparison, the color is lost and the particle size distribution is wider. The latter having a multiple structure is preferable in the present invention. A preferred embodiment of the present invention is to use silver halide grains with regular structure or morphology. That is, the weight or number of silver halide grains is at least 8.
A silver halide emulsion in which 0's have a regular shape is used.

The silver halide grains with a regular structure or morphology used in the present invention mean grains that grow isotropically without including anisotropic growth such as twin planes, such as cubic, tetradecahedral, and regular grains. It has an octahedral, spherical, etc. shape. Methods for producing such regular silver halide grains are known, for example, J. Phot, Sai;
, 5, 332 (1961), B@r, Bunaen-
ges, Phys, Cham, 67,949 (196
3), engineering nt・rn.

Congress Photo, Sci, Tokyo (
1967) and others.

Such regular silver halide grains can be obtained by adjusting the reaction conditions when growing silver halide grains using a simultaneous mixing method. In such a simultaneous mixing method, silver halide grains are prepared by adding approximately equal amounts of a silver nitrate solution and a halide solution to an aqueous solution of a protective colloid while stirring vigorously.

The supply of silver ions and noride ions is necessary and sufficient for the growth of only existing grains, without dissolving the existing crystal grains as the crystal grains grow, and conversely not allowing the generation and growth of new grains. It is preferable to increase the growth rate continuously or stepwise within the critical growth rate for supplying silver halogenide, or within its permissible range. As this increasing method, equity No. 111848-36890,
It is described in No. 52-16364 and Japanese Unexamined Patent Publication No. Sho 55-142329.

This critical growth rate varies depending on temperature, 1) degree of HSPAgs agitation, composition of silver noloride grains, solubility, grain size, interparticle distance, crystal habit, or type and concentration of protective colloid, etc. It can be easily determined experimentally by methods such as microscopic observation of emulsion particles suspended in the phase and turbidity measurement.

Then, by increasing the addition rate at this furrow addition rate or within its allowable range, monodispersed emulsions,
A piece with a coefficient of variation of 20% or less can be obtained.

In order to obtain the above-mentioned monodisperse emulsion, it is particularly preferable to use seed crystals and grow grains by supplying silver ions and halide ions using the seed crystals as growth nuclei.

The wider the particle size distribution of this seed crystal, the wider the particle size distribution after particle growth. Therefore, in order to obtain a monodisperse emulsion, it is preferable to use seed crystals with a narrow particle size distribution at the seed crystal stage.

In carrying out the present invention, it is preferable to adopt an embodiment in which the mother liquor containing the protective colloid has a pAg of at least 10.5 during particle growth before chemical sensitization as described above.

Particularly preferably, an atmosphere with a very high bromine ion excess of 11.5 or more is passed through at least once.

By increasing the number of (111) planes and rounding the particles in this way, the effects of the present invention can be further enhanced.

The ratio of the (ill) plane of such particles to the total surface area is preferably 5 or more.

In this case, the increase rate of the (Ill) plane (the increase rate with respect to that before passing through the PAg atmosphere of 10.5 or more above)
is preferably 10% or more, more preferably 10 to 20%.

The outer surface of the silver halide grain is the (llll) plane or the (10
0) Regarding whether one of the surfaces is covered or how to measure its density, please refer to the report by Akira Hirata.
``Bulletin of the Society of Scientific Photography of Japan''A
13, pp. 5-15 (19, 63).

In the present invention, by once passing through an atmosphere in which the pAg of the mother liquor containing protective colloid is at least 1O05 during grain growth before chemical sensitization, the (Ill) plane increases by 5% or more according to Hirata's measurement method. You can easily check whether this is the case.

In this case, the above-mentioned PAg is applied before chemical sensitization, but preferably from the time when silver ions are added for the growth of silver halide grains to before the desalting process, especially after the addition of silver ions is completed. Therefore, it is preferable to carry out the so-called desalting step which is usually carried out before chemical sensitization. This is because it is easy to obtain a monodispersed emulsion with a narrow particle size distribution.

In addition, aging in an atmosphere where pAg is 1000 or more,
It is preferable to do this for 2 minutes or more.

By such PAg control, the number of (111) planes increases by 5 or more, and the shape becomes rounded q. As a result, it is possible to obtain a preferable particle in which the (tii) plane is 5 or more of the total surface area of the particle.

A stabilizer can be added to the silver halide emulsion thus prepared after completion of chemical sensitization. For example, 4-hydroxy-6-methyl-1,3,3-hatake, 7-tetopozyden, 5-mercapto-1-phenyltetrazole, 2-mercaptobenzothiazole, etc.
Any stabilizer known in the art can be used.

The silver halide photographic emulsion of the present invention can use gelatin, a gelatin derivative, a synthetic hydrophilic polymer, etc. as a protective colloid for the vehicle, and can further contain various photographic additives.

As the hardening agent, an arte compound, an S-triazine compound, a ketone compound, a halogen-substituted acid such as mucochloric acid, an ethyleneimine compound, a vinyl sulfofone compound, etc. can be used.

As the spreading agent, saponin, lauryl or oleyl monoether of polyethylene glycol, etc. are used.

There are no particular restrictions on the development accelerator, but thioether compounds, pei-raimidazole compounds (e.g.,
24427), quaternary ammonium salt,
Compounds such as polyethylene glycol can be used.

As a physical property improver, homo or copolymer such as alkyl acrylate, alkyl methacrylate, acrylic acid, etc.
- It is possible to contain a polymer coating consisting of - or the like.

The silver halide photographic emulsion of the present invention includes a compound obtained by addition copolymerizing glycidol and ethylene oxide to a phenol aldehyde condensate (for example, the one described in JP-A-51-56220), a lanolin-based ethylene oxide addition body, alkali metal salts and/or alkaline earth metals (for example, those described in JP-A-53-145022), water-soluble inorganic chlorides, and matting agents (
(Japanese Patent Application No. 54-69242), an addition condensate of glycidol and ethylene oxide to a phenolaldehyde condensate, and an antistatic agent such as a fluorine-containing succinic acid compound (Japanese Patent Application No. 104940/1982) are added. be able to.

Furthermore, a pH adjuster, a thickener, a graininess improver, a film surface improving matting agent, etc. can be contained.

As a support for obtaining the light-sensitive material of the present invention, a film made of polyethylene terephthalate, polycarbonate, polystyrene, polypropylene, cellulose acetate, etc. can be used.

The support is preferably one that has been subjected to the subbing treatment described in JP-A-52-104913, JP-A-59-19941, JP-A-59-19940, and JP-A-59-18949.

[Embodiments of the invention]

Hereinafter, specific examples of the present invention will be described.

However, the following examples are illustrative of the present invention, and the present invention is not limited thereto.

Example 1 Six types of emulsions I-1 to I-6 were prepared as described below.

First, a polydispersed silver iodobromide emulsion (I-1) containing 2.0 mots of silver iodide was obtained by a layer heating method.

Emulsion I-2 was prepared by the following method.

A potassium bromide solution containing 2.0 mol of potassium iodide and an ammoniacal silver nitrate solution were added to an aqueous gelatin solution using a double jet method while gradually increasing the flow rate to obtain a solution of 1.0 mol of potassium iodide.
A 5 μm silver iodobromide cubic monodisperse emulsion was obtained. Further, an ammoniacal silver nitrate solution and a potassium bromide solution were added by a double jet method, and a shell of pure silver bromide was covered. During this period, PAg was 10. The pH was gradually lowered from 9.0 to 8.0 while maintaining OK.

From this K, a cubic monodisperse emulsion 1-2-2 having an average grain size of 1.25 μm was obtained. Further, by the same method as this emulsion 1-2-2, a cubic monodisperse emulsion 1-2-1 with an average grain size of 1.65 μm and a cubic monodisperse emulsion 1- with an average grain size of 0.65 μm were prepared. I got 3-1. This emulsion 1-2-1 and the above emulsion 1-2-, 2 were mixed at a mixing ratio of 10:90 as shown in the table below to obtain emulsion I-2 as a sample.

Further, the emulsions I-2-2 and I-3-1 were mixed at a mixing ratio of 75:25 as shown in the table below to obtain emulsion I-3 as a sample.

Next, emulsions I-4 to I-6 were obtained as described below.

A monodisperse cubic emulsion of silver bromide emulsion containing 2.0 mol of silver iodide and having an average grain size of 0.3 μm was prepared by the double jet method while controlling the temperature at 60°C, pAg=8, and pH=2-0. I got it. An electron micrograph of this emulsion showed that the incidence of twin grains was less than 1% in number.

A portion of this emulsion was used as a seed crystal and grown as follows.

That is, the seed crystals were dissolved in a solution 8.56 containing protected gelatin and optionally ammonia kept at 40°C, and the pH was adjusted using glacial acetic acid.3. 2N ammoniacal silver ion/aqueous solution and halide aqueous solution by double jet method, No. Zri! The mixture was added according to the flow rate pattern shown in JK, and stirring and mixing were performed.

In this case, the ammonia concentration of this mother liquor is 0.6N.

By adjusting the pH to 9.7 and pAg to 7.6, 30 mot% Q silver monoxide was localized inside.

Next, the pAg was kept constant at 9.0, and the pH was changed from 9 to 8 in proportion to the amount of ammoniacal silver ions added to form a shell of pure silver bromide. Furthermore, 3 at the end of grain growth
Aging was performed at a pAgf of 11.5 minutes and the particles were rounded.

In this way, seven types of monodispersed emulsions 1-4-1 to 1-6-3 shown in Table 2 were prepared.

Three emulsions I-4 to I-6 were obtained by mixing three types of internally high iodine type monodisperse emulsions, each having a different average grain size, prepared in the same manner as the emulsion I-1. It is. Tsumashi,
Emulsions I-4 and I-5 are emulsions with an average grain size of 0.90μ (
I-4-1), 0.70μ emulsion (I-4-2),
0.35μ emulsion (I-4-3) respectively 9nia 3:
It was obtained by mixing 18 and 13:67:20. Emulsion I-6 is an emulsion with an average grain size of 0.95μ (I-6-
1), 0.80μ emulsion (I-6-2), 0.5
A 0μ emulsion (I-6-3) was obtained by mixing at a mixing ratio of 22:48:30. The composition of each sample is summarized in Table 2 below.Table 2 Emulsion l-4-1-l-4-3 obtained as above
゜l-6-1-l-6-3 (that is, emulsions I-4 to I-6
To each of the emulsions constituting the emulsions), sensitizing dyes of the following compounds (1), (2), and (2) were added, and then ammonium thiocyanate dichloroauric acid and Hypo were added to perform gold-sulfur sensitization.

The other emulsions were subjected to the same gold-sulfur sensitization without adding any sensitizing dye. Therefore, samples I-4 to I-6 are ortho-sensitized orthotypes, while the others are regular types. The compound ■ added as a sensitizing dye is one of the compounds represented by the above formula [E], and the compound ■ is represented by the formula [E]
(2)] and Compound (2) are each one of the compounds represented by the formula (I). Formula % of each compound Formula % (Compound of the present invention) Compound ■ C2H.

■ Compound ■ Compound ■ Then, add the usual stabilizers, hardeners, and coating aids.
glycidyl methacrylate 5 Q vt%, methyl acrylate i o vttsl butyl methacrylate)
A copolymer aqueous dispersion obtained by diluting 40 vt% of a copolymer consisting of three types of monomers to a concentration of 10 vt9J was coated on a polyethylene terephthalate film base without subbing. This emulsion was coated uniformly on both sides and dried to obtain a sensitometric sample.

Next, for samples I-1 to I-3, a fluorescent screen NS (regular type) manufactured by Konishi Roku Photo Industry was used.
For samples I-4 to I-6, a fluorescent screen KS (for orthotype) manufactured by the same company was used, and a tube voltage of 9
X-rays were irradiated through an aluminum wedge at 0 KV and a tube current of 50 mA. After that, Konishiroku Photo Industry QX-12
Using a 00 automatic developing machine, using XD-90 processing solution, 90
Second processing was performed to obtain a sensitometric curve. The results are shown in Table-3.

Exposure latitude was expressed as the difference in exposure amount (logarithm representation) between the respective optical densities.

In this case, the processing conditions were as described above, and the developer used was the developer-1 described above. This is a condition when using the above-mentioned automatic processor or developing processing solution.

However, the processing time may be in the range of about ±2 seconds, the processing temperature may be in the range of about ±IC, and the amount of hydroΦnon, which is a developing agent, may be in the range of about ±if in Xt.

Example 2 An attempt was made to evaluate sharpness using the same sample as in the example.

The sharpness was evaluated based on the MTF curve at 10°1.5, 2.
It was expressed as a value of 0.011 no/m. The measurement of MTF' is 0.
8~1011nes/MTF with square wave made of gourd lead
The measurement chart was placed in close contact with the back side of the front side of the fluorescent screen, and the sample surface was irradiated so that the density (background density) of the part not shielded by the lead square wave was 1.0 on both sides. .

Thereafter, the same development treatment as in Example 1 was performed.

The square wave pattern of the obtained sample was measured using a Sakshi Microdensitometer Model M-5 (manufactured by Konishiroku Photo Industry Co., Ltd.).
Scanning measurements were performed in a direction perpendicular to the rectangular wave. The aperture size at this time is 230/Jm in the parallel direction of the rectangular wave, 25 μm in the perpendicular direction, and the magnification is 1.
00 times.

The results are shown in Table-3.

Example 3 The same sample as in Example 1 was heated to 23°C relative temperature 35°C for about 2 hours.
% and was maintained at a constant temperature, and under these conditions, it was folded approximately 2,800 times with a radius of curvature of 2, and the pressure desensitization was measured.

Three minutes after folding, the sample was exposed to X using an aluminum wedge under the conditions of a tube voltage of 80 KV and a tube current of 100 mA.
A line was irradiated for 0.06 sec, and the same development process as in Example 1 was performed.

The degree of pressure desensitization of the obtained sample was visually evaluated. In addition, using this sample, graininess and high PHs
Deterioration of image quality caused by rapid processing at high temperatures was also visually evaluated.

Here, visual evaluation of desensitization performance due to pressure, graininess, and image quality caused by rapid processing was expressed on a five-point scale from best to worst, with 1 being the best, and the higher the number, the worse it was.

These results are also shown in Table-3.

As seen from Table 3, sample A that satisfies the conditions of the present invention
It was found that 1-4 to 1-6 had high sharpness, wide exposure latitude in low density and high density areas, and little pressure desensitization. In addition, these samples have granularity and
It was found that there was little deterioration in image quality due to high p■ and high temperature rapid processing.

As described above, according to the sample corresponding to the example of the present invention,
Good results are obtained which achieve the above objectives.

〔Effect of the invention〕

As described above, the X-ray sensitive material of the present invention has high sharpness and wide exposure latitude in low density areas and high density areas, and therefore can improve diagnostic performance when used for medical purposes. It has the effects of good performance, low pressure desensitization, and little deterioration in image quality.

[Brief explanation of the drawing]

Figure 1 shows direct X-ray sensitive materials of high-gamma type i (a) and low-gamma i type (a).
FIG. % zQta 9RnqtqJ, ie*amount-b(”?
-'／j;1mi'fl! ]? -J+:! . Figure 1 Re1. LO(]”

Claims (1)

[Claims] 1. In a characteristic curve on a rectangular coordinate system with the same unit length of the coordinate axes of optical density (D) and exposure dose (logE), a point with an optical density of 0.05 and a point with the same unit length of 0.30. Gamma (γ_1) created by
is 0.36 to 0.65, and optical density is 0.500
The gamma (γ_2) created by the point with the same 1.50 as the point is 2.7 ~
3.3, and has a gamma (γ_3) between 2.00 and 3.00 of optical density of 1.5 to 2.5. 2. The above silver halide photographic material has the following general formula [
I ] [II] and [III] The X-ray device according to claim 1, characterized in that it has at least one emulsion layer containing at least one compound selected from the compound group represented by [II] and [III]. Silver halide photographic material. General formula [I] ▲ Numerical formulas, chemical formulas, tables, etc. takes a sulfoalkyl group or a carboxyalkyl group. X＾−＿
1 is an anion, Z_1 and Z_2 are nonmetallic atomic groups necessary to complete the substituted or unsubstituted benzene ring, n is 1
or 2. (However, when forming an inner salt, n is 1.) [II] ▲ Numerical formulas, chemical formulas, tables, etc. ▼ [In the formula, R_4 and R_5 are substituted or unsubstituted alkyl groups, alkenyl or aryl group, and at least one of R_4 and R_5 is a sulfoalkyl group or a carboxyalkyl group. R_6 represents a hydrogen atom, a lower alkyl group, or an aryl group. X^-_2 represents an anion, Z_1 and Z_2 represent a group of nonmetallic atoms necessary to complete a substituted or unsubstituted benzene ring, and n represents 1 or 2. (However, when forming an inner salt, n is 1.) [III] ▲ Numerical formulas, chemical formulas, tables, etc. ▼ [In the formula, R_7 and R_9 are each substituted or unsubstituted lower alkyl group, R_8 and R_1_0 are lower alkyl groups, hydroxyalkyl groups, sulfoalkyl groups, carboxyalkyl groups, X^-_3 is an anion, Z_1 and Z_2 are nonmetallic atomic groups necessary to complete the substituted or unsubstituted benzene ring, n represents 1 or 2. (However, when forming an inner salt, n is 1.)
]