JPH052973B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a silver halide photographic material for high-sensitivity X-rays, and more particularly to a silver halide photographic material for high-sensitivity X-rays suitable for use in combination with a specific fluorescent intensifying screen. Recently, in X-ray photography using silver halide photographic materials, there has been a strong demand to reduce the exposure dose, especially with the increase in medical X-ray examinations. Intensifying screens, fluorescent plates, and the like have been used to meet this demand, but in recent years, with advances in medical X-ray inspection technology, large-capacity X-ray generators have been installed. However, in imaging that requires such large doses, it is desirable to further reduce the exposure dose, and for this purpose, halogen for X-rays is used in combination with highly sensitive photosensitive materials or intensifying screens with high amplification factors. There is a strong demand for the development of silver oxide photographic materials. In recent years, fluorescent intensifying screens containing fluorescent components have been widely used as intensifying screens used in combination with such silver halide photographic materials for X-rays. Fluorescent intensifying screens containing rare earth compounds as the fluorescent component are particularly excellent and have been suitably used. Two sheets of such fluorescent intensifying screens are usually used, and a silver halide photosensitive material for X-rays coated on both sides with a high-sensitivity silver halide emulsion is inserted, and the X-rays are applied onto the photosensitive material that is in close contact with the screen. irradiate. The irradiated X-ray image emits fluorescence on the surface of the fluorescent intensifying screen, and the brightness is amplified and recorded on the silver halide emulsion layer. At this time, the silver halide photographic light-sensitive material color-sensitized according to the fluorescence brightness is recorded with high efficiency and high sensitivity. Silver halide photographic materials color-sensitized to long wavelengths are said to be useful as silver halide photographic materials for X-rays, and various color-sensitized emulsions have been used; The reality is that sensitivity has not been achieved. In order to obtain sufficient sensitivity, increasing the amount of dye has the disadvantage that the storage stability of the light-sensitive material deteriorates. Further, when the development process is performed quickly, there is a problem in that color staining remains due to the increased amount of dye. As a result of intensive research, the present inventors have discovered a silver halide photographic material for X-rays that is fully compatible with a fluorescent intensifying screen containing a rare earth compound. An object of the present invention is to provide a silver halide photographic material for X-rays suitable for use in combination with a fluorescent intensifying screen containing a terbium-activated rare earth compound as a fluorescent component. The above object is a silver halide photographic material for X-rays used in combination with a fluorescent intensifying screen containing a rare earth compound activated with terbium as a fluorescent component, the silver halide photographic material comprising: , containing silver halide grains that have been reduction-sensitized by adding a water-soluble silver salt to a silver halide emulsion during the growth of the silver halide grains, and containing at least one compound represented by the following general formula []. This is achieved by a silver halide photographic light-sensitive material for X-rays, which is characterized by containing. General formula [] [In the formula, Z ₁ and Z ₂ are nonmetallic atomic groups necessary to complete the substituted or unsubstituted benzene ring, R ₁ and R ₂
are substituted or unsubstituted alkyl groups (e.g. methyl group, ethyl group), alkenyl groups (e.g. allyl group), aryl groups (e.g. phenyl group,
naphthyl group), R ₃ is a substituted or unsubstituted sulfoalkyl group having 2 to 6 carbon atoms (e.g. sulfomethyl group, sulfoethyl group), X is an anion, n
represents 1 or 2. (However, when the dye forms an inner salt, n is 1.) The present invention will be described in detail below. The fluorescent screen used in the present invention is made of a rare earth compound activated with terbium (Tb), especially a compound of the general formula []X ₂ O ₂ S:Tb [where X is lanthanum (La), cerium ( Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium ( Represents an element selected from Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Su), and yttrium (Y). ] A fluorescent intensifying screen containing a rare earth oxysulfide as a fluorescent component is preferably used. Typical specific examples of compounds represented by the above general formula [] that are effectively used in the present invention are listed below, but the dyes that can be used in the present invention are not limited thereto. [Example dye] These dyes used in the present invention can be easily synthesized by known methods, for example, the method described in Japanese Patent Publication No. 13821/1982 or a method analogous thereto. Furthermore, the effect of the present invention can be obtained by adding and containing the dye used in the present invention alone in the emulsion.
If necessary, other sensitizing dyes may be added in combination within a range that does not impair the effects of the present invention. Next, typical dyes that can be added in combination with the dye according to the present invention are illustrated. In the present invention, the expression that silver halide grains are "ring-sensitized during the growth of silver halide grains" refers not only to the manufacturing method in which the silver halide grains are ring-sensitized while they are growing. means that even if the silver halide grains are ring-sensitized in a state where they are not grown, the production method in which the ring-sensitized silver halide grains are grown after the ring-sensitization is included. . That is, it means that it was manufactured by a manufacturing method that includes a manufacturing method in which ring-sensitized silver halide grains are grown. The ring element sensitization carried out in the present invention is carried out by adding a water-soluble silver salt to the silver halide emulsion as carried out during the growth of the silver halide grains of the silver halide emulsion. As the water-soluble silver salt, silver nitrate is preferred, and so-called silver ripening included in ring sensitization is carried out by adding the water-soluble silver salt. The pAg during silver ripening is suitably 1 to 6, preferably 2 to 4 (here, the pAg value is the common logarithm of the reciprocal of the Ag ⁺ concentration). The conditions for ring sensitization are a temperature of approximately 30°C to 80°C.
℃, time is about 10 minutes to 200 minutes, pH is about 5 to 11,
Preferably, pAg is in the range of about 1-10. Further, the following chemical sensitizers can be added to the emulsion at any time before, during or after the ring sensitization. i.e. sulfur sensitizers such as sodium thiosulfate,
Thiourea, etc.; Noble metal sensitizers, such as gold sensitizers, such as chlorauric acid salts, gold trichloride, etc., palladium sensitizers, such as palladium chloride, chloropalladate salts, etc., platinum compounds, iridium compounds, etc. selenium sensitizers such as selenite, selenourea, etc., and these may be used alone or in combination of two or more. It is preferred that the ring-sensitized emulsion of the present invention be subjected to gold sensitization and/or sulfur sensitization after the desalting step, since high sensitivity can be obtained. Furthermore, ring element sensitization can also be carried out after the above-mentioned gold sensitization and/or sulfur sensitization is completed. The compound represented by the general formula [] of the present invention (hereinafter referred to as the compound of the present invention) is incorporated into the silver halide photographic emulsion containing the ring-sensitized silver halide grains of the present invention. It can be incorporated directly into the emulsion, or in coating compositions for layers adjacent to the emulsion layer (for example, protective layers, anti-irradiation layers, filter layers, other intermediate layers, etc.) in photographic light-sensitive materials. They may be added and incorporated into the emulsion (ie, emulsion layer) by diffusion during or after the coating process. In order to incorporate the compound of the present invention into the constituent layers of the silver halide photographic light-sensitive material, it is advantageous to add it as a solution to the coating composition for the constituent layers. Various solvents can be used for this purpose, but preferably water or an organic solvent that is water-miscible and does not adversely affect the silver halide emulsion or the like;
For example, methanol, ethanol, isopropyl alcohol, fluorinated alcohol, ethylene glycol monomethyl ether, dimethylformamide,
Acetonitrile and the like are preferred, and these may be added alone or dissolved in a mixed solvent. When the compound of the present invention is added to a silver halide emulsion, the timing of addition varies depending on the type and purpose of the photographic light-sensitive material that uses the silver halide emulsion as a light-sensitive layer, but essentially, the timing of addition differs depending on the type and purpose of the photographic material that uses the silver halide emulsion as a light-sensitive layer, but essentially It may be added at any time. However, it is not preferable to add it before desalting because it will be eluted by desalting, and it is preferable to add it after the second ripening. It is more preferable to add it to the constituent layer coating composition containing the silver halide emulsion immediately before coating. The amount of the compound of the present invention added depends on the type of silver halide used in the silver halide photographic emulsion, the grain size and crystal habit of the silver halide, and the presence of photographic additives such as stabilizers and sensitizing dyes. , or depending on the processing temperature for the silver halide photographic emulsion and the composition of the processing solution. However, in general, the total amount of dye added is 10 mg to 500 mg per mole of silver halide.
It can be used within the range of 30mg, but preferably 30mg
It is desirable to use it in the range of ~200 mg. Furthermore, the compound of the present invention may be added to the silver halide photographic emulsion along with other compounds added for the purpose of preventing the occurrence of fog or a decrease in sensitivity during the manufacturing process, storage, and processing process of the silver halide photographic emulsion. It is okay to have both exist at the same time. These compounds include the famous 4-hydroxy-6-methyl-
Any antifoggant known in the art can be used, including 1,3,3a,7-tetrazaindene, 5-mercapto-1-phenyltetrazole, 2-mercaptobenzothiazole, and the like. The silver halide grains used in the present invention are, for example, “The Theory of the
Neutral method, acidic method, ammonia method, forward mixing, back mixing, double jet method, controlled dosing double jet method, etc. described in literature such as "Photographiec Process" 4th edition, published by Macmillan (1977), pp. 88-104. It can be manufactured by applying a method such as a method, a convergence method, a core/shell method, or the like.
As the silver halide composition, silver chloride, silver bromide, silver chlorobromide, silver iodobromide, silver chloroiodobromide, etc. can be used. There are no particular restrictions on the grain size, grain size distribution, crystal habit, morphology (normal crystal, twin crystal, etc.) of the silver halide grains, but silver halide grains with a relatively uniform grain size of 0.1 to 2 μm are preferred. Further, these silver halide grains or silver halide emulsions may contain an iridium salt and/or a rhodium salt in order to improve flash exposure characteristics. The silver halide photographic emulsion used in the present invention can use gelatin as a vehicle, can also use gelatin derivatives, synthetic hydrophilic polymers, etc. in combination with gelatin, and can also contain various photographic additives. be able to. As the hardening agent, aldehyde compounds, ketone compounds, halogen-substituted acids such as mucochloric acid, ethyleneimine compounds, vinyl sulfon compounds, etc. can be used. As the extender, saponin, lauryl or oleyl monoether of polyethylene glycol, etc. are used. The development accelerator is not particularly limited, but compounds such as benzimitazole compounds (for example, those described in JP-A-49-24427) and quaternary ammonium salts can be used. As physical property improvers, alkyl acrylate,
A polymer latex made of a homo- or copolymer of alkyl methacrylate, acrylic acid, etc. can be contained. The silver halide photographic emulsion according to the present invention includes compounds obtained by addition copolymerizing glycidol and ethylene oxide to a phenolaldehyde condensate (for example, those described in JP-A-51-56220), lanolin-based ethylene oxide, etc. adduct and alkali metal salt and/or alkaline earth metal salt (for example, those described in JP-A-55-70837),
Water-soluble inorganic chloride and matting agent
161230), an addition condensate obtained by addition-condensing glycidol and ethylene oxide to a phenolaldehyde condensate, and a fluorine-containing succinic acid compound (Japanese Patent Application Laid-open No. 48520/1983). Furthermore, PH adjusters, thickeners, granularity improvers,
etc. can be contained. Next, the present invention will be explained in more detail with reference to Examples, but the embodiments of the present invention are not limited thereto. In the following examples, the following dyes were used for comparison. Example 1 A silver iodobromide gelatin emulsion containing 2.0 mol% of silver iodide was controlled at 60°C, pAg = 8, and PH = 2.0.
A monodisperse cubic emulsion with an average grain size of 0.5 μm was obtained by the double jet method. Divide this emulsion into two,
One of them was heated at 60℃ with the addition of silver nitrate solution, pAg
= 3, silver ripening was performed at PH = 6, and emulsion No. 2 was obtained.
The remaining one was not subjected to silver ripening and was designated as Emulsion No. 1. A solution containing a silver nitrate solution, potassium bromide and potassium iodide was further added to these emulsions by a double jet method to grow 1.2μ grains. After gold sensitization and sulfur sensitization of these emulsions,
After adding sensitizing dyes as shown in Table 2 to each, coated on both sides of a polyethylene terephthalate film base with a ^silver content of 50 mg/dm2.
It was dried to create a photosensitive material for X-rays. This photosensitive material was passed through an optical wedge and sandwiched between two fluorescent intensifying screens, and was irradiated with X-rays under the two conditions shown in Table 1.

[Developer]

Anhydrous sodium sulfite 70g Hydroquinone 10g Sodium carbonate (-hydrate) 20g 1-phenyl-1,3-pyrazolidone 0.35g Potassium hydroxide 5g 5-methyl-benztriazole 0.05g Potassium bromide 5g Glutaraldehyde bisulfite 15g Ice Vinegar Acid Finish with 8g water. Regarding the obtained sample after development, fog and
The sensitivity value was determined from the point showing the density of fog +1.0. The results are shown in Table 2. However, the sensitivity was measured under the conditions of 1 and 2 in Table 1 above.
Relative sensitivity is shown with the sensitivity of the sample obtained using the NS combination set as 100.

[Table] As is clear from Table 2, a photosensitive material in which the compound of the present invention is added to a ring-sensitized silver halide emulsion inside silver halide grains, and a rare earth oxysulfide activated with terbium. When a fluorescent intensifying screen containing a substance as a fluorescent component is combined, a non-color sensitized photosensitive material, a fluorescent intensifying screen (NS) containing calcium tungstate as a fluorescent component, and a fluorescent screen (NS) according to the present invention are obtained. A combination with a fluorescent intensifying screen, a combination of a light-sensitive material color-sensitized with a dye other than the present invention - NS and an intensifying screen according to the present invention, and a light-sensitive material color-sensitized with a dye according to the present invention. Compared to the combination with NS,
It can be seen that a silver halide emulsion for X-rays with high sensitivity can be obtained while suppressing the occurrence of fog. Example 2 A sample prepared in the same manner as in Example 1 and left under high temperature and high humidity was irradiated with X-rays at 100 KVp, 100 mA, and 0.06 sec.
The samples were developed and tested for storage stability as shown in Table 3 below. The results are shown in the same table. Note that the sensitivity is expressed as a relative value, with the sensitivity of a non-color sensitized sample immediately after coating being taken as 100.

【table】

[Table] As is clear from Table 3, the samples according to the present invention also have excellent storage stability. Example 3 A sample prepared and treated in the same manner as in Example 1 was visually inspected for color retention. The results are shown in Table 4. Contamination is ranked 1 to 3 from least to 3.
Shown in stages. Note that 1 indicates that there is no problem in practical use, 2 indicates that there is a problem in practical use, and 3 indicates that there is a problem so severe that it cannot be used.

【table】

[Table] As is clear from Table 4, the samples according to the present invention achieve high sensitivity without causing color contamination.

Claims (1)

[Scope of Claims] 1. A silver halide photographic light-sensitive material for X-rays used in combination with a fluorescent intensifying screen containing a rare earth compound activated with terbium as a fluorescent component, the silver halide photographic material The light-sensitive material contains silver halide grains that have been reduction-sensitized by adding a water-soluble silver salt to a silver halide emulsion during the growth of the silver halide grains, and at least one of the compounds represented by the following general formula []. A silver halide photographic material for X-rays, characterized in that it contains one of the following. General formula [] [In the formula, Z ₁ and Z ₂ are nonmetallic atomic groups necessary to complete the substituted or unsubstituted benzene ring, R ₁ and R ₂
are each a substituted or unsubstituted alkyl group, alkenyl group, or aryl group, R ₃ is a carbon atom number of 2 to
6 substituted or unsubstituted sulfoalkyl group, X
represents an anion, and n represents 1 or 2 (however, when the dye forms an inner salt, n is 1). ]