JP2719656B2 - X-ray photographic materials with excellent sharpness and granularity - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an X-ray photographic material, and more particularly to a silver halide X-ray photographic material having excellent sharpness and granularity.

[Conventional technology]

In the field of silver halide photographic light-sensitive materials, it is desired that any type of light-sensitive material has excellent sharpness and graininess of the obtained image, and a good balance between the two, so that a high-quality image can be obtained. It is.

In particular, X-ray photographic materials are required to be excellent in sharpness and granularity, well-balanced, and easy to read an obtained image, particularly when used for medical use.

X-ray photographic materials, on the other hand, are generally colored blue to reduce fatigue during observation and have the effect of enhancing the image. However, when such blue coloring is applied, the blue density also affects the sharpness and graininess of an image.

In conventional X-ray photographic materials, the blue color density is not always the best from the viewpoint of sharpness and granularity. In particular, optical density (D) and exposure (log E)
X-ray photographic material for obtaining an image having a gamma (γ ₁ ) of 0.80 to 1.25 between the point of visual optical density of 0.40 and the point of 1.00 in the characteristic curve on a rectangular coordinate system having the same coordinate axis unit The above tendency is large.

[Problems to be solved by the invention]

As described above, in an X-ray photographic material from which an image giving a specific range of gamma can be obtained, the blue coloring may affect sharpness and graininess. That is, in order to obtain a favorable effect by blue coloring, sharpness and granularity are deteriorated, and the balance between the two may be lost. For example, when trying to improve the observability of a photograph by improving the graininess, the sharpness sometimes deteriorates.

The present invention solves the above problems and provides an X-ray photographic material capable of obtaining a desired gamma image, having excellent sharpness and granularity, and having a good balance between the two, for example, without deteriorating sharpness. Another object of the present invention is to provide a blue-colored X-ray photographic material capable of maintaining good granularity for observing photographs.

[Means for solving the problem]

An object of the present invention is to provide an X-ray photographic material having at least one silver halide emulsion layer on each side of a transparent support, wherein an optical density (D) and an exposure amount (log E) have the same right angle rectangular coordinate unit. In the characteristic curve on the coordinate system, the gamma (γ ₁ ) formed by the point of visual optical density 0.40 and the point 1.00 of the transmitted light is 0.80 to 1.25, and the blue density of the photosensitive material is the visual transmitted light (D _V ) At 0.185-0.215
And an image which is 0.065 or less in blue transmitted light (D _B ) is obtained.

When used for medical purposes, the X-ray photographic light-sensitive material of the present invention can be particularly suitably used for imaging a region requiring a wide latitude, such as a chest. In particular, it can be designed to have a low contrast in order to describe a low density portion.

According to the present invention, an X-ray sensitive material having a gamma within the above range can be obtained by setting the range of the present invention with respect to the prior art, whereby excellent sharpness and granularity and a good balance between the two can be obtained. And arrived at the present invention.

Preferably, the X-ray photographic light-sensitive material of the present invention has the above-mentioned gamma (γ ₁ ) and the above-mentioned gamma (γ ₁ ) in the characteristic curve when it is processed by the following processing-1 under the conditions using the following developer-1. This is to obtain an image having the blue density.

Processing-1 Developer-1 The above processing-1 was carried out by Konica X-ray automatic developing machine SRX-5.
01 (manufactured by Konica Corporation) in the 90-second processing mode corresponds to the time of each process of development, fixing, washing and drying.

In the present invention, the optical density (D) and the exposure amount (log
The characteristic curve on the rectangular coordinate system having the same coordinate axis unit of E) is, for example, as shown in FIG. 1, the logarithm of the exposure amount is plotted on the horizontal axis, and the optical density D (visual optical density) is plotted on the vertical axis. Is a photographic characteristic curve in a coordinate system in which the ordinate and the abscissa have the same scale (equal intervals) when a rectangular coordinate system is used.

At this time, the gamma (γ ₁ ) created by the point of visual optical density 0.40 and the point of 1.00 is the straight line connecting the point of visual optical density = 0.40 on the characteristic curve of FIG. Tan θ when the angle made is θ.

In the present invention, the visual optical density refers to a standard processing condition, in particular, one sheet of an unexposed photosensitive material (only fog appears) when processed with the processing-1 and the developing solution-1. This is a value obtained by measuring the transmitted light density through an amber filter attached to 65 (Konica Corporation).

In the present invention, the visual transmitted light (D _V ) refers to a standard processing condition, in particular, an unexposed light-sensitive material (only fog appears) when processed with the processing-1 and the developing solution-1.
The quotient is obtained by measuring the transmitted light density through an amber filter attached to a densitometer (PDA-65 (Konica Corporation)) and dividing the value by 3.

In the present invention, the blue transmission light D _B, standard processing conditions, particularly when processed by the processing 1 and developer -1, and three sheets of unexposed photosensitive material (appearing only fog), The transmitted light density was measured through a blue filter attached to a densitometer (PDA-65 (manufactured by Konica Corporation)), and the value was measured as 3
Is the quotient divided by

In order to make the X-ray photographic material of the present invention into the shape of the characteristic curve as described above, various modes can be adopted. For example, such a characteristic curve is obtained when exposure is performed using a fluorescent intensifying screen. For example, for orthophotos, use Konica Corporation's KO series and SR series rare earth fluorescent intensifying screens.For regular use, use Konica Corporation's NS series fluorescent intensifying screens. This is the characteristic curve shape obtained in FIG.

The shape of the characteristic curve was measured by a distance method in which the distance between the X-ray tube and the photosensitive material was changed to adjust the amount of exposure.

For the X-ray photographic light-sensitive material of the present invention, the blue density
The blue color for establishing the relationship between D _V and D _B may be used to color only the support, only the photographic constituent layer applied thereon, or a combination of both colors. .

For coloring, an appropriate dye can be used. For example, the following exemplified compounds can be used as the dye.
However, it is not limited to this.

 Hereinafter, the present invention will be described in more detail.

The X-ray photographic material of the present invention has at least one silver halide emulsion layer on each side of a transparent support. On each surface, one or more protective layers may be further formed.

The silver halide emulsion layer of the light-sensitive material of the present invention contains silver iodide.
It is preferable to contain silver iodide-containing silver halide grains in the range of 0.20 mol to 3.80 mol.

In particular, a light-sensitive material having a silver halide emulsion layer containing such silver iodide-containing silver halide grains in an amount of 60% or more of all silver halide grains is preferable.

When the silver iodide content is less than 0.20 mol%, the progress of development and fixing is rapid and the processability is good, which is advantageous in this respect. However, the silver halide has a high sensitivity and a large covering power. Since silver halide grains having a large grain size must be used at a high silver content, and the processability deteriorates in this respect, the silver iodide content is preferably 0.20 mol% or less from this viewpoint. If the silver iodide content exceeds 3.80 mol%, the processability is degraded although there is almost no increase in sensitivity, and there is no point in increasing the silver iodide content. It is preferably at most mol%.

The silver halide used in the light-sensitive material of the present invention, particularly when the silver halide is a silver halide containing silver iodide, may have any composition, for example, about 0 to 3 mol% as a halogen atom. A chlorine atom may be contained.

The silver iodide-containing silver halide grains are grains of silver iodobromide, silver chloroiodobromide, silver chloroiodide, etc. Among them, silver iodobromide is preferred. The silver iodide content of the silver iodide-containing silver halide grains is preferably from 0.50 mol% to 3.00 mol%.

A further preferred embodiment of the present invention is to use monodisperse particles.

When the embodiment using monodisperse particles is employed in the present invention, preferable monodisperse particles include, for example, JP-A-59-1094.
No. 5, No. 59-177535, and No. 62-123445 can be used. When tabular grains are used, JP-A-58-113927 and JP-A-58-127921 describe examples.
Nos. 63-138342, 63-284272, and 63-305343, and related techniques can be used.

These silver halide grains have a rapid development progress, and can reduce a decrease in sensitivity and contrast of a characteristic curve even in a rapid processing.

In a further preferred embodiment of the present invention, the dissolution time of the photosensitive silver halide emulsion layer in sodium hydroxide at 50 ° C is
It is 18 minutes or more and 130 minutes or less.

If the dissolution time is less than 18 minutes at 50 ° C., the sensitivity is advantageous, but the amount of water absorption increases and the drying load increases, which may cause a problem in rapid processing. May have large performance fluctuations,
If this is longer than 18 minutes, there is no problem in this respect, and in this sense, the dissolution time is preferably longer than 18 minutes. Further, it is preferable that the dissolving time is 130 minutes or less, since there is no problem such as deterioration of processability and occurrence of uneven development.

Here, the dissolution time of the silver halide emulsion layer in sodium hydroxide is measured under the following conditions.

That is, in a 500 ml beaker, 500 ml of a 1.5% by weight aqueous solution of sodium hydroxide at 50.0 ° C. was placed, and this was used to obtain 1 cm × 5 c
The measurement is performed using a rectangular sample of m as a measurement sample. The beaker containing the aqueous sodium hydroxide solution during the measurement,
Constant temperature bath (sodium hydroxide solution in beaker is 50.0 ℃
The water is kept at a constant temperature by stabilizing the water at a temperature of about 50.2 to 51 ° C. The sample is immersed vertically in a beaker containing 500 ml of the above-mentioned sodium hydroxide solution by 3 cm and allowed to stand. At this time,
The time until the silver halide emulsion layer starts dissolving (the amount of silver halide eluted is usually about 1 to 3% at this time) is measured, and this is defined as the dissolution time.

In a further preferred embodiment of the present invention, the thickness of the photographic component layer including the silver halide emulsion layer is 3.9 μm or less.

Here, the photographic constituent layer refers to an undercoat layer (for example, JP-A No.
52-104913, 59-18949, 59-19940, 59-
Layers such as antihalation layer, crossover cut layer, colored layer, emulsion layer, intermediate layer, protective layer, antistatic layer, etc. The total thickness of the layers. The measurement is performed at 23 ° C and a relative humidity of 55 ° C.

Local irregularities such as a matting agent are eliminated. The film thickness can be measured by a film thickness measuring instrument, but can also be calculated by calculation from the amount and specific gravity of the material applied on the support.

When the film thickness is 3.90 μm or less, there is no problem that sensitivity and sensitometric characteristics are easily changed, and there is no deterioration in fixing, washing and drying. A thin film is favorable in terms of processability. However, if it is too thin, it may cause deterioration in graininess and increase in fog, or the film may become stiff and may deteriorate the equipment transportability.

More preferably, the thickness of the photographic constituent layer on the surface on which the photosensitive emulsion is coated is preferably 2.50 to 3.70 µm.

Next, preferred dyes that can be used in the X-ray photosensitive material of the present invention will be described.

The dye may be contained in the support, may be contained in any photographic constituent layer, or may be contained in both. The use of such a dye allows the transmitted light density to fall within the range of the present invention.

Preferred dyes that can be used have an absorption maximum,
A hydrophobic dye at 570 to 700 μm, such as anthraquinone type, azo type, azomethine type, indoaniline type, oxonol type, triphenylmethane type, carbocyanine type, styryl type, and the like; Those with values can be selected. When the hydrophobic dye is contained in, for example, a photographic component layer, it can be dispersed in a high-boiling solvent and / or a low-boiling solvent described below and used in the form of a dispersion. When it is contained in the support, appropriate means such as kneading can be used.

Hereinafter, specific examples of dyes that are preferably used in the practice of the present invention will be shown, but the dyes that can be used are not limited thereto. The following compound example N
o.1 to 36 can be preferably contained in a photographic component layer, and Compound Examples Nos. 37 to 56 can be preferably contained in a support.

The above exemplified compounds are described in JP-A-61-48854 and JP-A-61-7838.
No. 60-243654, No. 60-32851, No. 57-26849, and a method described in Yutaka Hosoda, "Dye Chemistry", Gihodo (1957).

The grain shape, structure and the like of the silver halide grains used in the silver halide emulsion layer of the X-ray photographic light-sensitive material of the present invention are not limited at all, but are preferably described in JP-A-63-23154.
And the particles described in Japanese Patent Application No. 62-6890 (page 24, line 2 to page 42, line 5).
58-113928, 58-127921, 59-105636, 60
-147727, 63-138342, 63-284272, 63-
Tabular grains as disclosed in JP-A-305343 can be used.

As described above, it is preferable to use monodispersed silver halide grains as described above. However, general polydispersed grains and the above-described tabular grains can be used in combination at any ratio.

As the transparent support used in the present invention, it is preferable to use a flexible transparent support usually used for photographic light-sensitive materials. Useful as a flexible transparent support are cellulose nitrate, cellulose acetate, cellulose acetate butyrate,
A film made of a semi-synthetic or synthetic polymer such as polystyrene, polyvinyl chloride, polyethylene terephthalate, and polycarbonate, or an α-olefin polymer (eg, polyethylene, polypropylene, etc.).

The effects of the present invention can be further enhanced by using a vinyl sulfone-based hardening agent described below in the silver halide photographic light-sensitive material of the present invention.

Here, the vinyl sulfone hardener is a compound having a vinyl group bonded to a sulfonyl group or a group capable of forming a vinyl group. Preferably, it has at least two vinyl groups bonded to a sulfonyl group or groups capable of forming a vinyl group. For example, the following general formula [VS−
The compound represented by the formula (I) is preferably used in the light-sensitive material of the present invention.

General formula [VS-I] L- (SO ₂ -X) _{m In the} above general formula [VS-I], L is an m-valent linking group, and X is -CH = CH ₂ or -CH ₂ CH ₂ Y Y is a group capable of leaving in the form of HY by a base, such as a halogen atom,
Sulfonyloxy group, sulfoxy group (including salt), 3
Represents a residue of a secondary amine.

Examples of X, -CH = CH ₂ or -CH ₂ CH ₂ Cl and the like are preferable.

m represents an integer of 2 to 10. When m is 2 or more, a plurality of —SO ₂ —Xs may be the same or different.

Examples of the m-valent linking group L include an aliphatic hydrocarbon group (for example, an alkylene group, an alkylidene group, an alkylidine group or the like, or a group formed by combining these groups), an aromatic hydrocarbon group (for example, an arylene group). Or a group formed by combining them), -O-, NR'- (R 'represents a hydrogen atom or an alkyl group having preferably 1 to 15 carbon atoms), -S-,- N-, -CO-, -SO
—, —SO ₂ —, or —SO ₃ — is an m-valent group formed by combining one or more bonds represented by —SO ₃ — or the like, and when two or more NR′— May combine with each other to form a ring. The linking group L further includes those having a substituent such as a hydroxy group, an alkoxy group, a carbamoyl group, a sulfamoyl group, an alkyl group or an aryl group.

Hereinafter, typical specific examples of vinyl sulfone hardeners that can be preferably used in the practice of the present invention will be shown.
However, it is not limited to the following examples.

VS-1 H ₂ C = CHSO ₂ CH ₂ SO ₂ CH = CH ₂ VS−2 H ₂ C = CHSO ₂ (CH ₂ ) ₂ SO ₂ CH = CH ₂ VS−3 H ₂ C = CHSO ₂ (CH ₂ ) ₃ SO ₂ CH = CH ₂ VS-4 H ₂ C = CHSO ₂ CH ₂ OCH ₂ SO ₂ CH = CH ₂ VS-5 H ₂ C = CHSO ₂ (CH ₂ ) ₂ O (CH ₂ ) ₂ SO ₂ CH = CH _{2 VS-8 H 2 C = CHSO} 2 CH 2 CONHCH 2 NHCOCH 2 SO 2 CH = CH 2 VS-9 H 2 C = CHSO 2 CH 2 CONH (CH 2) 2 NHCOCH 2 SO 2 CH = CH 2 VS-10 H _{2 C = CHSO 2 CH 2 CONHCH} 2 CH 2 NHCOCH 2 SO 2 CH = CH 2 Vinyl sulfone hardeners that can be used are, for example, German Patent 1,100,942 and US Patent 3,490,911.
No. 44-, aromatic compounds such as those described in
Nos. 29622, 47-25373 and 47-24259, alkyl compounds linked by a hetero atom, sulfonamides and ester compounds described in JP-B-47-8736, etc. 1,3,5-Tris [β- (vinylsulfonyl) -propionyl] hexahydro-s-triazine or JP-B-50-35807, JP-A-51-44164 as described in JP-A-49-24435 and the like. And alkyl compounds described in JP-A-59-1894.
No. 4, etc., and the like.

The vinyl sulfone hardener is dissolved in water or an organic solvent, and is generally added to a binder (e.g., gelatin) in an amount of 0.
It is preferably used in an amount of from 005 to 20% by weight, more preferably from 0.02 to 10% by weight.

For the addition to the photographic constituent layer, a batch method or an in-line addition method can be adopted.

As other additives and means, it is preferable to use the methods described in JP-A-63-23154 and Japanese Patent Application No. 62-6890 (page 77, line 18 to page 117, line 9). In addition, as a treatment agent,
It is preferable to use those described on page 117, line 10 to page 123, line 12. As other additives, those described in Research Disclosure No. 176, 22-31 (RD 17643, 1978) are preferably used.

That is, the photosensitive material may contain optional additives, which are described in Research Disclosure, Vol. 176, No.
17643 (December 1978) and 187, No. 18716 (November 1976
Monthly), and the relevant locations are summarized in the following table.

Known photographic additives that can be used in the preparation of emulsions of the light-sensitive material to which the present invention is applied are also described in the above two Research Disclosures, and the locations described in the following table are shown.

The processing method of the light-sensitive material of the present invention is arbitrary, and an appropriate processing method may be used according to each embodied light-sensitive material.

As the processing solution such as a developing solution and a fixing solution used in the processing of the photosensitive material, an appropriate one can be used according to the photosensitive material.

Preferably, the light-sensitive material of the present invention is processed under the conditions corresponding to the following formula from the balance of developability, fixability, and drying property.

l ^0.75 x T = 50 to 124 0.7 <l <4.0 where l is the processing length (unit: m) when the silver halide photographic light-sensitive material is processed, and T is the light-sensitive material passing through l. (In seconds).

Further, the light-sensitive material of the present invention is preferably processed by an automatic developing machine, and in this case, it is particularly preferable to be processed by a roller transport type automatic developing machine under conditions corresponding to the following formula.

l ^0.75 × T = 50 to 124 0.7 <l <4.0 where l is the length (unit: m) from the core of the first roller at the insertion port to the core of the final roller at the drying outlet of the roller transport type automatic processor. Here, T is the time (unit: seconds) required for the photosensitive material to pass through the above l.

When processing using an automatic developing machine, it is preferable to use a roller transport type automatic developing machine, in which case the number of all transport rollers is a value obtained by dividing the processing length l by the number of rollers is 0.01 to 0.04. Is preferable. The time of each processing part is preferably in the following range.

Insertion + Development + Transition 25-40% Fixation + Transition 12-25% Washing + Transition 10-25% Squeeze + Drying 25-45% Total 100% [Examples] Hereinafter, the present invention will be further described by examples. It goes without saying that the present invention is not limited by the embodiments.

Example 1 Preparation of Grains Monodispersed silver iodobromide grains containing 2.0 mol% of silver iodide having an average grain size of 0.2 μm were used as nuclei, and silver iodobromide containing 30 mol% of silver iodide was adjusted to pH 9.8, Growing at pAg7.8, then adding equimolar potassium bromide and silver nitrate at pH8.2, pAg9.1, and having an average silver iodide grain having an average silver iodide content of 2.2 mol 0.375 μ
m (-1), 0.640 µm (-2), 1.42 µm (-
Three types of monodisperse emulsion particles of 3) were prepared.

The emulsion was subjected to desalting of excess salts by a usual aggregation method. That is, while maintaining the temperature at 40 ° C., a formalin condensate of sodium naphthalene sulfonate and an aqueous solution of magnesium sulfate were added to cause aggregation. After removing the supernatant, pure water up to 40 ° C. was further added, and an aqueous solution of magnesium sulfate was added again to cause aggregation, and the supernatant was removed.

The thus-obtained silver halide grains-1,-
The dispersibility of the particle diameters of 2 and 3 was S / <0.16, and the particles had good monodispersity.

Preparation of Particles 5.5% 1.5% gelatin solution containing 0.17 mol of potassium bromide
To 1 l, while stirring at 80 ° C. and pH 5.9, 2.1 mol of potassium bromide and 2.0 mol of silver nitrate were added as a solution over 2 minutes by a double jet method. The rBr was maintained at 0.8 (consumed 0.53% of the total silver nitrate used). The addition of the potassium bromide solution was stopped and the silver nitrate solution was continued for 4.6 minutes (consuming 8.6% of the total silver nitrate used). Then the potassium bromide solution and the silver nitrate solution were added simultaneously for 13 minutes.
During this time, the pBr was maintained at 1.2, and the addition flow rate
It was accelerated to 2.5 times (4% of the total silver nitrate used).
Consumed 3.6%). The addition of the potassium bromide solution was stopped and the silver nitrate solution was added for 1 minute (4.
Consumed 7%).

A 2.0 mol solution of potassium bromide containing 0.55 mol of potassium iodide was added along with the silver nitrate solution over 13.3 minutes. During this time, the pBr was maintained at 1.7 and the flow rate was accelerated at completion to 1.5 times that at the start (35.9% of the total silver nitrate used was consumed). Add 1.5 g / mol A of sodium thiocyanate to this emulsion.
g was added and held for 25 minutes. 0.60 mol of potassium iodide and silver nitrate were added in a solution by a double jet method at an equal flow rate for about 5 minutes until the pBr reached 3.0 (about 6.6% of the total silver nitrate used was consumed). The amount of total silver nitrate consumed was about 11 moles. Thus, an emulsion containing tabular silver iodobromide grains having an average grain diameter of 1.62 μm and an aspect ratio of about 16: 1 was prepared. This grain has the total projected area of the silver iodobromide grain.
It accounts for more than 80%.

Preparation, processing and evaluation of the sample The thus obtained silver halide grains and pure water were added so that the volume per mole was 500 ml, and the temperature was set to 55 ° C. At a weight ratio of 200: 1, the total amount is -1 per mole of silver halide.
820 mg, -2 600 mg, -3 is 360 mg, but was added as 700 mg, with ammonium thiocyanate per mole of silver -1 4 × 10 ^-3 mol after 10 minutes, -2 2 × 10 ^-3 mol, -3 was added to 1.0 × 10 ⁻³ mol, and 3 × 10 ⁻³ mol, and appropriate amounts of chloroauric acid and hypo were added to initiate chemical ripening.

 At this time, the pH was 6.15 and the silver potential was 50 mV.

15 minutes before completion of chemical ripening (70 minutes after starting chemical ripening)
200 mg of potassium iodide per mole of silver were added to the mixture, after 5 minutes 10% (wt / Vol) acetic acid was added to reduce the pH to 5.6, and the pH was maintained for 5 minutes, after which potassium hydroxide was added. A 0.5% (wt / Vol) solution was added to return the pH to 6.15, and then 4-hydroxy-6-methyl-1,3,3a, 7a-tetrazaindene was added. −1,
After mixing −2 and −3, the adjusting solution (A) to which the photographic emulsion coating additive described later was added and the particles-3 were mixed, and the same adjusting solution (B) to which the same photographic emulsion coating additive was added was added. ) Was prepared.

To make each sample in Table 1, the particles were mixed as follows. Numerical values represent percent by silver content ratio.

The pH after preparation of the photographic emulsion coating solution was 6.40, and the silver potential was 74 mV.
(35 ° C.) using sodium carbonate and potassium bromide solution.

Using this emulsion coating solution, a sample was prepared as follows. That is, the photographic emulsion layers are as gelatin of 2.0 [g / m ^2]
The silver content is 1.90 [g /
m ² ), and a protective layer solution is prepared using the additives described below, and the protective layer has a gelatin weight of 1.15 g / g.
m ² ], both sides were simultaneously coated on the support at a speed of 80 m / min using two slide hopper type coaters, and dried for 2 minutes and 20 seconds to obtain a sample. As a support, a copolymer aqueous dispersion obtained by diluting a copolymer composed of three monomers of 50 wt% of glycidyl methacrylate, 10 wt% of methyl acrylate, and 40 wt% of butyl methacrylate so as to have a concentration of 10 wt% was used. 175 applied as undercoat liquid
A polyethylene terephthalate film base of μm was used, and the film base was colored with the exemplified compound No. 39 exemplified as a dye (the amount of the dye added was 85 mg / mg).
m ² ]).

Further, for coloring, a sample was prepared by adding a dispersion liquid dispersed by a dye dispersion method described later in an amount shown in Table 1.

All the obtained samples had a dissolution time in sodium hydroxide of 50 ° C. for 27 to 31 minutes.

The obtained sample was sandwiched between fluorescent intensifying screen KO-250 (sold by Konica Corporation), irradiated with X-ray at a tube voltage of 90 KVP, 20 mA for 0.05 seconds, and subjected to a sensitometric characteristic curve by a distance method. create a, γ _1, D _V, was determined the D _B. Processing is Konica automatic processor S
While using RX-501, the developer-
1. Fixing solution XF-SR (manufactured by Konica Corporation) was used as the fixing solution. (The automatic developing machine SRX-501 operates in a 90-second mode, wherein the developing according to claim 1 is performed for 25.5 seconds, fixing is performed for 15.9 seconds, washing is performed for 12.4 seconds, and drying is performed.
This is equivalent to 25.2 seconds. The fixing temperature of the automatic processor used was 33 ° C, and the temperature of washing water was
1.5 l / min was supplied at 18 ° C.

The comparative dyes used for sample preparation are as follows.

The spectral sensitizing dyes used for sample preparation are as follows.

Additives used in the emulsion solution (coating solution for photosensitive silver halide emulsion) are as follows. The amount of addition is shown in an amount per mole of silver halide.

1,1-dimethylol-1-bromo-1-nitromethane 70 m
g t-butyl-catechol 400 mg polyvinylpyrrolidone (molecular weight 10,000) 1.0 g styrene-maleic anhydride copolymer 2.5 g trimethylolpropane 10 g diethylene glycol 5 g nitrophenyl-triphenylphosphonium chloride 50
mg Ammonium 1,3-hydroxybenzene-4-sulfonate 4g 2-Mercaptobenzimidazole-5-sodium sulfonate 1.5mg The additives used in the protective layer solution are as follows. The amount of addition is indicated by the amount per coating solution.

Lime-treated inert gelatin 68 g Acid-treated gelatin 2 g Polymethyl methacrylate, matting agent with an area average particle diameter of 3.5 μm 1.1 g Silicon dioxide particles (matting agent with an area average particle diameter of 1.2 μm) 0.5 g Ludox AM (Dupont colloidal silica) 30 g 2,4-dichloro-6-hydroxy 1,3,5-Triazine sodium salt aqueous solution 2% (hardener) 12ml Formalin 35% (hardener) 2.ml Glyoxal aqueous solution 40% (hardener) 2.0ml C ₁₁ H ₂₃ CONH (CH ₂ CH ₂ O) ₅ H 2.0 g A dye emulsified dispersion was prepared as follows.

From the exemplified dyes, 10 kg of each of the dyes shown in Table 1 was weighed and dissolved in a solvent composed of 12 l of tricresyl phosphate and 85 l of ethyl acetate at 55 ° C. This is called an oil-based solution. On the other hand, an anionic surfactant (the following AS) was dissolved at 1.35 kg at 45 ° C. 270 ml of a 9.3% gelatin aqueous solution was prepared. This is called an aqueous solution.

Put the oil-based and water-based solutions in a dispersion kettle and adjust the liquid temperature to 40.
While controlling the temperature to maintain the temperature in the dispersion vessel 2 as shown in FIG. 2, the high-speed rotating propeller 1 for dispersion in the dispersion vessel 2 was rotated at 6,500 revolutions / minute while the pressure in the dispersion vessel 2 was increased from 760 mmHg for 60 minutes. The pressure was gradually reduced to 100 mmHg, and then dispersion was continued under the same conditions for 20 minutes. In FIG. 2, reference numeral 3 denotes a dispersion liquid stirring propeller.

The following additives and water were added to the resulting dispersion to make it 240 kg, and then cooled and solidified.

The area average particle size of the obtained dispersion is all 0.08 to 0.10 μ
m.

As an evaluation of the image quality of each of Sample Nos. 1 to 62, the graininess and sharpness were evaluated using a real sample.

The actual photo was taken using a fluorescent screen KO-250 using a chest phantom.
Was taken at a tube voltage of 90 KVP. The processing was the same as that of the sensitometry (the same automatic developing machine, processing agent, processing temperature and processing time).

In each sample, the exposure time was adjusted so that the density of the same portion as the portion having a density of 0.50 of sample No. 1 was within 0.50 ± 0.02, and actual photographed samples Nos. 2 to 62 were obtained.

Each of the obtained live-action samples No. 2 to 62 was visually observed with a density of 0.50 ± 0.
The granularity of the overlapping part of the heart and lung, which corresponds to 02, was evaluated.

The sharpness was measured using a funk test chart SMS5853 (sold by Konica Medical). Processing was performed under the same tube voltage, intensifying screen, and processing conditions as in the actual photography. Each sample was exposed so that the exposure amount was 0.50 ± 0.02 with the average density of shading produced by the Funk test chart.

Graininess evaluation A: Very good and almost no recognition as grains B: Good but slight image composition as grains C: No problem in image interpretation but worried about granular D: Graininess in image interpretation Roughness begins to affect slightly E: Graininess is poor and it is difficult to read fine parts F: Graininess is bad and it is impossible to read the whole image Can be identified C: Can be identified up to 6 LP / mm with loupe D: Can be identified up to 5 LP / mm with loupe E: Can be identified up to 4 LP / mm with loupe As shown in Table 1, there gamma ₁ is in the range of 0.85 to 1.25, and a D _V is from 0.185 to .215 D _B is 0.065 samples,
It can be seen that an image having excellent graininess and sharpness and an excellent balance between the two can be obtained.

〔The invention's effect〕

As described above, according to the present invention, X-rays having excellent color and sharpness and having a good balance between the two can be obtained by using a blue-colored X
It can be obtained by radiographic exposure.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram in the case where the relationship between the logarithm of the exposure amount (log E) and the visual density in the present invention is shown by a characteristic curve on a rectangular coordinate system having the same coordinate axis unit. FIG. 2 is a schematic view of a dispersing vessel for explaining a method of dispersing dyes in Examples. γ ₁ …… The gamma created by the points of visual optical density 0.40 and 1.00.

Claims (2)

(57) [Claims] 1. An X-ray photographic light-sensitive material having at least one silver halide emulsion layer on each side of a transparent support, wherein the optical density (D) and the amount of exposure (log E) are in the same rectangular coordinate system. In the above characteristic curve, the gamma (γ) of the point of visual optical density of transmitted light of 0.40 and the point of 1.00
₁ ) is 0.80 to 1.25, and the blue density of the photosensitive material is visual transmitted light (D _V )
X-ray photographic light-sensitive material for obtaining an image having a blue transmission light (D _B ) of 0.065 or less. 2. The image according to claim ₁ , wherein said gamma (γ ₁ ) and said blue density image are obtained in said characteristic curve when processed under the following processing-1 and developing solution-1 conditions. X-ray photosensitive material. Processing-1 Developer-1