JP3222975B2 - Radiation image forming assembly and processing method of silver halide photographic material constituting the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-sided photosensitive silver halide photographic material for medical use, and a photographing method and a processing method thereof. The present invention relates to an X-ray imaging system capable of obtaining an image having excellent diagnostic ability.

(Background of the Invention) In the medical field, the number of X-ray photographs is increasing due to an increase in the number of diagnostics such as health checkups and an increase in examination items for improving diagnostic accuracy. There is a strong demand for reduction and faster development than before. In recent years, from the viewpoint of global environmental protection,
2. Description of the Related Art In various industries, technological development for reduction and detoxification of industrial waste is being promoted. There is also a strong demand in the photographic industry to reduce development and fixing waste liquids, and medical photographic materials are no exception.

[0003]

2. Description of the Related Art Conventionally, a combination of a silver halide photographic light-sensitive material having a photographic emulsion layer on both sides and a radiation intensifying screen is set to a specific condition, and X-ray photography excellent in a balance between image quality and sensitivity is provided. Attempts have been made to find a system. For example, JP-A-2-266344, JP-A-2-266344.
297544, Photographic Science and Engineering, Vol. 26, No. 1 (19
82) An example is described in P40 and the like. However, the average projected area equivalent diameter of all grains having an aspect ratio of 5 or more is 1.0 μm or less, and tabular grains having an average aspect ratio of 5 or more are used.
An X-ray imaging system that can reduce the replenishment amount of the processing solution at 8 g or less and has a crossover value of 19% or less and obtains an image with excellent diagnostic performance at a low exposure dose that can be applied to mass screening has been available. unknown.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a medical silver halide photographic light-sensitive material capable of reducing a replenishing amount of a processing solution, enabling rapid processing and providing a radiographic image with excellent diagnostic performance, and a photographing and processing system therefor. Is to provide.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is to: (i) load a photosensitive material between two radiation screens;
In radiographic imaging assembly of X-ray exposure comprising Te, sensitive
The optical material has a silver halide emulsion layer composed of radiation-sensitive silver halide grains on both sides of a transparent support, and at least one silver halide emulsion layer.
In one emulsion layer, at least 60% of the total projected area of the silver halide grains has an average aspect ratio of 5 or more and an aspect ratio of 5 or more.
All of the above grains consist of tabular grains having an average diameter equivalent to the projection area of 1.0 μm or less, the coated silver amount per side is 1.4 g / m ² or less, and the front side of the silver halide photographic light-sensitive material. A light- sensitive material having a crossover value of 19% or less which is emitted to the rear photosensitive layer of the silver halide photographic material with respect to light emitted from the radiation intensifying screen disposed at
And at least one of the two radiation screens
28% for X-rays with X-ray energy of 80KVp
It is characterized by a radiation intensifying screen showing the above absorption
Radiation imaging assembly.

(Ii) Radiation image formation as described in (i) above
Roll the silver halide photographic material that constitutes the assembly
4 cuts (10 x 12 inches) using a transport type automatic developing machine
When the replenishment amount of the developer and fixer is less than 16 ml each,
Yes, dry to dry processing in 90 seconds or less
For processing silver halide photographic light-sensitive materials.

(Iii) Radiation image formation as described in (i) above
The silver halide photographic light-sensitive material constituting the assembly is
Mercapto group and hydride containing two nitrogen atoms as constituent atoms
At least one substituent other than a roxy group and a hydrogen atom
6-membered hetero compound and one member as a constituent atom of the 5-membered ring
Containing at least one but not more than three nitrogen atoms and reducing the number of mercapto groups
Developer containing a 5-membered hetero compound
Processing of silver halide photographic light-sensitive material, characterized in that
Processing method.

[0008] (iv) method for processing a silver halide photographic material according to (iii) above, wherein the pH of the current image liquid is treated with a developer solution is 10 or less. Has been found to be achieved by:

The ideal of X-ray diagnosis is to minimize the amount of exposure to a subject and to draw out abnormal tissues in the body, thereby enabling a doctor to make an accurate diagnosis. On the other hand, it is important to reduce the amount of coated silver in order to reduce the replenishment amount of the processing solution and to enable rapid processing. However, simply decreasing the amount of silver applied to the light-sensitive material lowers the maximum density of the image, resulting in an X-ray image with low contrast and low diagnostic performance. The present invention solves this problem, and provides an X-ray image forming system by combining the photosensitive material described in (i) above with a radiation intensifying screen having high X-ray absorption and high brightness and sharpness. A radiographic image with excellent diagnostic ability can be obtained with a small replenishment amount of the processing solution, rapid processing is possible without lowering the sensitivity (ie, without increasing the amount of X-ray exposure). Furthermore, the above (iv),
The use of the developer of (v) reduces the so-called silver stains, which cause silver to accumulate and accumulate on the developer tanks and rollers and adhere to the photosensitive material. Is obtained.

As the halogen composition of the emulsion used in the present invention, silver chlorobromide, silver bromide, silver iodobromide, silver chloroiodobromide and silver chloride can be used. Here, the content of silver iodide is preferably at most 3 mol%, particularly preferably at most 1 mol%. The distribution of iodine in silver iodobromide grains may be uniform or may differ between the inside and the surface. The average particle size (equivalent circle diameter) of all particles having an aspect ratio of 5 or more is 0.5 μm to 1.0.
μm is preferred. For the preparation method of tabular grains, see Research Disclosure, 2
Volume 25, Item 22534, P20-P58, January,
1983 and Japanese Patent Publication No. 4-23769 can be referred to. In the present invention, the photosensitive silver halide emulsion may be a mixture of two or more kinds of silver halide emulsions. The emulsions to be mixed may differ in grain size, halogen composition, sensitivity and the like. For example, the same layer as a photosensitive silver halide emulsion comprising a spherical or potato-like photosensitive emulsion and a tabular grain having a grain size of 5 times or more the grain thickness or a different layer as described in JP-A-58-127921. May be used. When used in different layers, the light-sensitive silver halide emulsion composed of tabular grains may be on the side closer to the support or, conversely, on the side farther away.

In the photosensitive silver halide emulsion used in the present invention, at least 60% of the total projection area of silver halide grains has an average aspect ratio of 5 or more, and corresponds to the projection area of all grains having an aspect ratio of 5 or more. Tabular grains having an average diameter of 1.0 μm or less. The "aspect ratio" used herein refers to the ratio of the diameter of a particle (diameter equivalent to the projected area) to its thickness. The "diameter" of a grain is defined as the diameter of a circle having an area equal to the projected area of the grain when viewing the emulsion grains in electron micrographs. By determining the thickness and diameter of each grain from an electron micrograph having a shadow of the emulsion sample, tabular grains having a thickness of less than 0.2 μm and a diameter of 0.4 μm or more can be identified. From this, the aspect ratio of each tabular grain was calculated, and the average aspect ratio was calculated by averaging the ratio of all tabular grains in the sample having a thickness of less than 0.2 μm and satisfying the criteria of 0.4 μm or more in diameter. Obtainable. James and Higgi for "Projection Area"
ns, “Fundamentals of Photographic Theory” Morgan
and Morgan, New York, p. The tabular silver halide emulsions preferably used in the present invention include US Pat. Nos. 5,147,771, 5,171,659, 5,
147,772, 5,147,773, European Patent 514
742A and the like.

The silver halide emulsion used in the present invention has been chemically sensitized. As the method of chemical sensitization, known methods such as sulfur sensitization, selenium sensitization, tellurium sensitization, reduction sensitization, and gold sensitization can be used, and these are used alone or in combination. . Among the noble metal sensitization methods, the gold sensitization method is a typical one and uses a gold compound, mainly a gold complex salt. Noble metals other than gold, for example, complex salts such as platinum, palladium and iridium may be contained. Specific examples are U.S. Pat. No. 2,448,060 and British Patent 618,06.
No. 1 and the like. Examples of the sulfur sensitizer include sulfur compounds contained in gelatin, and various sulfur compounds such as thiosulfates, thioureas, thiazoles,
Rhodanins and the like can be used. Sulfur, selenium,
Tellurium sensitization is specifically described in Japanese Patent Application No. 4-222679. Stannous salts as reduction sensitizers,
Amines, formamidinesulfinic acid, silane compounds and the like can be used.

[0013] the total amount of coated silver of the double-sided sensitive material used in the present invention is 2.8 g / m ² or less, particularly 2.6g~1.8g / m ² is preferred. If the amount of silver applied is less than 1.8 g / m ^2, it is difficult to obtain X-ray photographic sensitivity while maintaining the maximum density of the developed silver image at 2.0 or more. The highest density of developed silver is 2.
0 or more, preferably 2.3 or more, more preferably 2.5
The above is desirable. The total amount of gelatin coated on both sides is 3
g to 6 g / m ² .

The silver halide photographic light-sensitive material used in the present invention is a cloth which emits light emitted from a radiation intensifying screen disposed in front of the light-sensitive screen to a rear photosensitive layer of the silver halide photographic light-sensitive material. Those prepared to have an over of 19% or less, particularly preferably 15% or less, are preferred. The measuring method of the crossover value is disclosed in
The method of 2828 is followed. Various techniques have been developed to reduce crossover. For example, there is an invention in which a spectrally sensitized high aspect ratio tabular grain emulsion disclosed in U.S. Pat. Nos. 4,425,425 and 4,425,426 is used as a light-sensitive silver halide photographic emulsion. Is 1
It is said to decrease to 5-22%. U.S. Pat. No. 4,803,150, Japanese Patent Application Laid-Open No. 2-264936, Japanese Patent Application No. Hei.
JP-A-99678 discloses a technique in which a microcrystalline dye layer which can be decolorized by a development treatment is provided between a support of a silver halide photographic material and the photosensitive layer to reduce crossover.

The film swelling ratio of the light-sensitive material used in the present invention is desirably 270% or less. Here, the swelling ratio is measured according to the method described in JP-A-58-111933. In the light-sensitive material of the present invention, a red-to-infrared absorbing solid disperse dye as described in JP-A-4-138449 is contained in an emulsion layer containing a silver halide emulsion and a protective layer for the purpose of improving safelight fog. be able to. Cyan and / or magenta dyes for adjusting the image tone used in the present invention are disclosed in Japanese Patent Application Nos. 3-352857 and 4-9065.
The dye described in No. 8 is useful. The dye for adjusting the image tone can be contained in a protective layer, an emulsion layer, a subbing layer of a support and a base support. Generally, both dope dyeing to the support and addition to the light-sensitive material layer are performed. It is desirable that the amounts of cyan and magenta dyes added to the light-sensitive material layer be 0.12 or less in R concentration and G concentration, respectively.

There are no particular restrictions on the various additives and the like used in the photographic light-sensitive material of the present invention, and for example, those described in the following applicable places can be used. Item The relevant point 1) Antifoggant, stabilizer From page 17, lower left column, line 17 to page 11, page 11, upper left column, line 7 and page 3, lower left column, line 2 of JP-A-2-68539 Page 4, lower left column. 2) Color tone improver JP-A-62-276539, page 2, lower left column, line 7 to page 10, lower left column, line 20; JP-A-3-94249, page 6, lower left column, line 15 to line 12. Page 11, right upper column, line 19. 3) Spectral sensitizing dyes JP-A-2-68539, page 4, lower right column, line 4 to page 8, lower right column. 4) Surfactant JP-A-2-68539, page 11, upper left column, line 14, antistatic agent, page 12 upper left column, line 9; 5) Matting agent, slip agent JP-A-2-68539, page 12, upper left column, line 10, plasticizer, line 10 in the upper right column, and page 14, line 10 in the lower left column, line 1, line 1 in the lower right column. 6) Hydrophilic colloid From page 11, upper right column, line 11 to lower left column, line 16 of JP-A-2-68539. 7) Hardener From page 17, lower left column, line 17 to page 13, upper right column, line 6 of JP-A-2-68539. 8) Support: Lines 7 to 20 in the upper right column on page 13 of JP-A-2-68539. 9) Crossover JP-A-2-264944, page 4, upper right column, line 20, upper right column, page 14 from the cut method. 10) Dyes and mordants JP-A-2-68539, page 13, lower left column, line 1 to page 14, upper left column, line 9. No. 3-24537, page 14, lower left column to page 16, lower right column. 11) Polyhydroxyl JP-A-3-39948, page 11, upper left column to benzenes, page 12, lower left column, EP Patent No. 452772A. 12) Layer structure JP-A-3-19841.

The radiation intensifying screen used in the present invention will be described in detail. The radiographic intensifying screen used in the assembly of the present invention can be easily obtained by manufacturing the radiographic intensifying screen having the X-ray absorption specified in the present invention by a conventionally known radiographic intensifying screen manufacturing technique. . For an example of an intensifying screen,
Research Disclosure, Item 18431,
See section IX. Radiation intensifying screens
The basic structure includes a support and a phosphor layer formed on one surface thereof. The phosphor layer is a layer in which the phosphor is dispersed in a binder (binder). In general, a transparent protective film is provided on the surface of the phosphor layer opposite to the support (the surface not facing the support) so that the phosphor layer is chemically altered or Protects against physical shock.

Preferred as a phosphor for use in the radiation intensifying screen used in the present invention are those represented by the following general formula. M _(wn) M ′ _n O _w X (M is at least one of metal yttrium, lanthanum, gadolinium, and lutetium, and M ′ is at least one of rare earth elements, preferably dysprosium, erbium, europium, holmium , Neodymium, praseodymium, samarium, cerbium, terbium, thulium, or ytterbium; X is an intermediate chalcogen (S, Se, or Te) or halogen; n is 0.0002-0.2; And w is
It is 1 when X is a halogen, and 2 when X is a chalcogen. Specific examples of the radiation intensifying phosphor preferably used in the radiation intensifying screen of the present invention include the following phosphors.
Terbium activated rare earth oxysulfide phosphor [Y ₂ O ₂ S: Tb, Gd
₂ O ₂ S: Tb, La ₂ O ₂ S: Tb, (Y, Gd) ₂ O ₂ S: Tb, (Y, Gd) ₂ O
₂ S: Tb, Tm, etc.], terbium activated rare earth oxyhalide phosphor (LaOBr: Tb, LaOBr: Tb , Tm, LaOCl: Tb, La
OCl: Tb, Tm, GdOBr: Tb, GdOCl: Tb, etc., thulium-activated rare earth oxyhalide phosphors (LaOBr: Tm, LaOCl: Tm
etc) . Among the above-mentioned phosphors, a terbium-activated gadolinium oxysulfide (oxysulfide) -based phosphor is particularly preferable as the phosphor used in the radiation intensifying screen of the present invention. The terbium-activated gadolinium oxysulfide phosphor is described in detail in US Pat. No. 3,725,704.

The application of the phosphor layer on the support is generally carried out by using a coating method under normal pressure as described below. That is, a coating solution is prepared by mixing and dispersing a particulate phosphor and a binder in an appropriate solvent, and this coating solution is irradiated with radiation under normal pressure using a coating means such as a doctor blade, a roll coater, or a knife coater. After directly applying on the support of the sensitive screen, the solvent is removed from the coating film, or the coating solution is applied in advance on a temporary support such as a glass plate under normal pressure, and then the solvent is removed from the coating film. By removing the phosphor-containing resin thin film and peeling it off from the temporary support and joining it to the support of the radiation intensifying screen, the phosphor layer is provided on the support. . The radiographic intensifying screen used in the present invention can be manufactured by the usual method as described above, but the thermoplastic elastomer as described below is used as a binder, and a compression treatment is carried out to obtain a phosphor. Those manufactured by increasing the filling rate (that is, reducing the porosity in the phosphor layer) can also be preferably used.

The sensitivity of the radiation intensifying screen basically depends on the total light emission of the phosphor contained in the panel,
The total amount of light emission depends not only on the emission luminance of the phosphor itself but also on the content of the phosphor in the phosphor layer. A high content of the phosphor also means that absorption of radiation such as X-rays is large, so that higher sensitivity can be obtained and at the same time, image quality (particularly, granularity) is improved.
On the other hand, when the phosphor content in the phosphor layer is constant, the layer thickness can be reduced as the phosphor particles are more densely packed, so that the spread of emitted light due to scattering is reduced. And a relatively high sharpness can be obtained.

In order to manufacture the above-mentioned radiographic intensifying screen, a) a step of forming a phosphor sheet composed of a binder and a phosphor, and b) placing the phosphor sheet on a support, Adhering the phosphor sheet on a support while compressing at a temperature equal to or higher than the softening temperature or the melting point of the phosphor sheet. First, step a) will be described. The phosphor sheet serving as the phosphor layer of the radiation intensifying screen is prepared by applying a coating solution in which the phosphor is uniformly dispersed in a binder solution onto a temporary support for forming the phosphor sheet, drying, and temporarily supporting the phosphor sheet. It can be manufactured by removing it from the body. That is, first, a binder and phosphor particles are added to an appropriate organic solvent, and the mixture is stirred and mixed to prepare a coating solution in which the phosphor is uniformly dispersed in the binder solution. The binder has a softening temperature or a melting point of 30 ° C to 150 ° C.
Is used alone or together with another binder polymer. Since the thermoplastic elastomer has elasticity at normal temperature and becomes fluid when heated, it is possible to prevent the phosphor from being damaged by the pressure at the time of compression. Examples of the thermoplastic elastomer include polystyrene, polyolefin, polyurethane, polyester, polyamide, polybutadiene, ethylene vinyl acetate, polyvinyl chloride, natural rubber, fluorine rubber, polyisoprene, chlorinated polyethylene, styrene-butadiene rubber, and silicone rubber. Can be mentioned. The component ratio of the thermoplastic elastomer in the binder may be not less than 10% by weight and not more than 100% by weight, but the binder may be composed of as many thermoplastic elastomers as possible, particularly 100% by weight. preferable.

Examples of the solvent for preparing the coating solution include lower alcohols such as methanol, ethanol, n-propanol and n-butanol; hydrocarbons containing chlorine atoms such as methylene chloride and ethylene chloride; acetone, methyl ethyl ketone and methyl isobutyl ketone. Ketones such as methyl acetate, ethyl acetate, and butyl acetate; esters of lower alcohols with lower alcohols; ethers such as dioxane, ethylene glycol monoethyl ether, and ethylene glycol monomethyl ether; and mixtures thereof. The mixing ratio between the binder and the phosphor in the coating solution varies depending on the characteristics of the intended radiographic intensifying screen, the type of the phosphor, and the like. In general, the mixing ratio between the binder and the phosphor is from 1: 1 to 1: 1. 1: 100
(Weight ratio), and particularly preferably in the range of 1: 8 to 1:40 (weight ratio). The coating solution has a dispersant for improving the dispersibility of the phosphor in the coating solution, and also for improving the binding force between the binder and the phosphor in the formed phosphor layer. Various additives such as a plasticizer may be mixed.
Examples of dispersants used for such purposes include phthalic acid, stearic acid, caproic acid, and lipophilic surfactants. And as an example of a plasticizer,
Phosphoric esters such as triphenyl phosphate, tricresyl phosphate and diphenyl phosphate; phthalic esters such as diethyl phthalate and dimethoxyethyl phthalate; glycolic esters such as ethyl phthalylethyl glycolate and butyl phthalyl butyl glycolate; Examples thereof include polyesters of polyethylene glycol and aliphatic dibasic acid, such as polyesters of ethylene glycol and adipic acid, and polyesters of diethylene glycol and succinic acid. Next, the coating solution containing the phosphor and the binder prepared as described above is uniformly applied to the surface of the temporary support for forming a sheet to form a coating film of the coating solution. This coating operation is performed by a normal coating means,
For example, it can be performed by using a doctor blade, a roll coater, a knife coater, or the like.

The temporary support is, for example, glass, a metal plate,
Alternatively, it can be arbitrarily selected from known materials as a support for the radiation intensifying screen. Examples of such materials include films of plastic substances such as cellulose acetate, polyester, polyethylene terephthalate, polyamide, polyimide, triacetate, and polycarbonate, metal sheets such as aluminum foil and aluminum alloy foil, ordinary paper, baryta paper, and resin. Pigment paper containing pigments such as coated paper and titanium dioxide,
Examples thereof include paper or sheets of ceramics such as alumina, zirconia, magnesia, and titania sized with polyvinyl alcohol or the like. A coating solution for forming a phosphor layer is applied on the temporary support, dried, and then peeled off from the temporary support to form a phosphor sheet to be a phosphor layer of the radiographic intensifying screen. Therefore, it is preferable to apply a release agent on the surface of the temporary support in advance so that the formed phosphor sheet can be easily peeled off from the temporary support.

Next, step b) will be described. First, a support for a phosphor sheet formed as described above is prepared.
This support can be arbitrarily selected from the same materials as the temporary support used when forming the phosphor sheet. In a known radiographic intensifying screen, a phosphor layer is provided in order to strengthen the bond between the support and the phosphor layer or to improve the sensitivity or the image quality (sharpness, granularity) of the radiographic intensifying screen. A polymer material such as gelatin is applied to the surface of the support on the side to form an adhesion-imparting layer, or a light-reflective layer made of a light-reflective material such as titanium dioxide, or a light-absorbent material such as carbon black It is known to provide an absorption layer or the like. The support used in the present invention can also be provided with these various layers, and the configuration thereof can be arbitrarily selected according to the desired purpose and application of the radiographic intensifying screen. The phosphor sheet obtained in step a) is placed on a support, and then the phosphor sheet is bonded to the support while compressing at a temperature equal to or higher than the softening temperature or the melting point of the binder. In this way, by utilizing the method of compressing the phosphor sheet without pre-fixing it on the support, the sheet can be spread thinly and not only to prevent damage to the phosphor, but also to fix the sheet. As compared with the case where pressure is applied, a high phosphor filling rate can be obtained even at the same pressure. Examples of the compression apparatus used for the compression processing of the present invention include generally known apparatuses such as a calender roll and a hot press. For example,
The compression treatment by a calender roll is performed by placing the phosphor sheet obtained in step a) on a support and passing the phosphor sheet at a constant speed between rollers heated to a temperature higher than the softening temperature or melting point of the binder. However, the compression device used in the present invention is not limited to these devices, and may be any device capable of compressing the above-mentioned sheet while heating it. The pressure at the time of compression is preferably 50 kgw / cm ² or more.

In a usual radiographic intensifying screen,
As described above, a transparent protective film for physically and chemically protecting the phosphor layer is provided on the surface of the phosphor layer opposite to the side in contact with the support. Such a transparent protective film is preferably provided also for the radiation intensifying screen of the present invention. The thickness of the protective film is generally in the range of about 0.1 to 20 μm. The transparent protective film is, for example, a cellulose derivative such as cellulose acetate or nitrocellulose;
Alternatively, a solution prepared by dissolving a transparent polymer such as polymethyl methacrylate, polyvinyl butyral, polyvinyl formal, polycarbonate, polyvinyl acetate, or a synthetic polymer such as a vinyl chloride / vinyl acetate copolymer in a suitable solvent is used as a fluorescent light. It can be formed by a method of applying to the surface of the body layer. Alternatively, a plastic sheet made of polyethylene terephthalate, polyethylene naphthalate, polyethylene, polyvinylidene chloride, polyamide, and the like; and a protective film forming sheet such as a transparent glass plate are separately formed, and an appropriate adhesive is applied to the surface of the phosphor layer. It can also be formed by a method such as bonding by using.

As the protective film used in the radiation intensifying screen used in the present invention , a film formed by a coating film containing a fluorine-based resin soluble in an organic solvent is particularly preferable. The fluorine-based resin refers to a polymer of an olefin containing fluorine (fluoroolefin) or a copolymer containing an olefin containing fluorine as a copolymer component. The film formed by the coating film of the fluororesin may be crosslinked. Protective film made of fluororesin removes dirt such as plasticizer that leaks out of the film when it comes into contact with other materials or X-ray film, etc. There are advantages that can be. When a fluorine-based resin soluble in an organic solvent is used as a material for forming a protective film, a film prepared by dissolving the resin in an appropriate solvent is applied and dried to easily form a film. That is, the protective film is formed by uniformly applying a coating liquid for a protective film forming material containing an organic solvent-soluble fluororesin to the surface of the phosphor layer using a doctor blade or the like, and drying this. This protective film may be formed simultaneously with the formation of the phosphor layer by simultaneous multi-layer coating. The fluororesin is a polymer of a fluorine-containing olefin (fluoroolefin) or a copolymer containing a fluorine-containing olefin as a copolymer component, and is made of polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyfluoroethylene, or the like. Examples include vinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, and fluoroolefin-vinyl ether copolymer. Fluorinated resins are generally insoluble in organic solvents, but copolymers containing fluoroolefins as copolymer components are soluble in organic solvents depending on the other constituent units (other than fluoroolefins) to be copolymerized, A solution prepared by dissolving the resin in an appropriate solvent is applied on the phosphor layer, and dried to easily form a protective film. Examples of such a copolymer include a fluoroolefin-vinyl ether copolymer. In addition, polytetrafluoroethylene and its modified product are also soluble in a suitable fluorinated organic solvent such as a perfluoro solvent, and therefore, like the copolymer containing the above-mentioned fluoroolefin as a copolymer component, the coating is performed. Thus, a protective film can be formed. The protective film may contain a resin other than the fluorine-based resin, and may contain a cross-linking agent, a hardening agent, an anti-yellowing agent, and the like. However, in order to sufficiently achieve the above-mentioned object, the content of the fluororesin in the protective film is suitably at least 30% by weight, preferably at least 50% by weight, and more preferably at least 70% by weight. It is preferable that it is above. Examples of the resin other than the fluorine-based resin contained in the protective film include a polyurethane resin, a polyacryl resin, a cellulose derivative, polymethyl methacrylate, a polyester resin, and an epoxy resin.

The protective film of the intensifying screen used in the present invention may be made of one of a polysiloxane skeleton-containing oligomer and a perfluoroalkyl group-containing oligomer.
Alternatively, it may be formed from a coating film containing both. The polysiloxane skeleton-containing oligomer has, for example, a dimethylpolysiloxane skeleton, preferably has at least one functional group (eg, a hydroxyl group), and has a molecular weight (weight average) of 500 to 100,000. Is preferred. In particular, the molecular weight is 1000-1
00000, more preferably 300
It is preferably in the range of 0 to 10,000. Also, a perfluoroalkyl group (eg, a tetrafluoroethylene group)
The contained oligomer desirably contains at least one functional group (for example, hydroxyl group: -OH) in the molecule, and preferably has a molecular weight (weight average) of 500 to 100,000. In particular, the molecular weight is 1000-1
00000, preferably 100
It is preferably in the range of 00 to 100,000. If an oligomer containing a functional group is used, a crosslinking reaction occurs between the oligomer and the protective film-forming resin during the formation of the protective film, and the oligomer is incorporated into the molecular structure of the film-forming resin. Even if the conversion panel is used repeatedly for a long time or the operation such as cleaning the surface of the protective film, the oligomer is not removed from the protective film, and the effect of adding the oligomer is effective for a long time. Use is advantageous. The oligomer is preferably contained in the protective film in an amount of 0.01 to 10% by weight, particularly preferably 0.1 to 2% by weight. Perfluoroolefin resin powder or silicone resin powder may be contained in the protective film. The perfluoroolefin resin powder or the silicone resin powder preferably has an average particle diameter in the range of 0.1 to 10 μm, and particularly preferably has an average particle diameter in the range of 0.3 to 5 μm.
The perfluoroolefin resin powder or silicone resin powder is preferably contained in the protective film in an amount of 0.5 to 30% by weight based on the weight of the protective film, and particularly preferably in an amount of 2 to 20% by weight. And an additional 5 to 15% by weight
Is preferably contained in an amount of

The radiation intensifying screen used in the present invention is:
As mentioned above, it has high X-ray absorption and high sensitivity,
As its characteristics, the contrast transfer function (CTF)
It is preferably prepared so as to show 0.70 or more at a spatial frequency of 1 line / mm (1 p / mm) and 0.30 or more at a spatial frequency of 3 lines / mm (1 p / mm). It is particularly preferable that the protective layer of the radiation intensifying screen is a transparent synthetic resin layer having a thickness of 5 μm or less formed on the phosphor layer. By using such a thin protective layer, the distance from the phosphor of the radiation intensifying screen to the silver halide photosensitive material is shortened, which contributes to the improvement of the sharpness of the obtained X-ray image.

The X-ray absorption of the radiographic intensifying screen was measured by transmitting X-rays generated from a tungsten target tube operated at 80 KVp with three-phase power supply through an aluminum plate having a thickness of 3 mm. Tungsten
The sample was intensified to reach a sample intensifying screen 200 cm from the anode, and then the amount of X-rays transmitted through the intensifying screen was reduced by 50% from the phosphor layer of the intensifying screen.
Measurement is performed using an ionizing dosimeter at the position after cm, and the amount of X-ray absorption is determined. As a reference, the X-ray dose at the above measurement position measured without passing through the intensifying screen is used. To measure and calculate the contrast transfer function from the radiation intensifying screen to the photosensitive material, use a rectangular chart as Eastman
It can be carried out using a sample baked on a single-sided MRE made by Kodak.

In the present invention, a developing agent used in the developer is preferably a combination of dihydroxybenzenes and 1-phenyl-3-pyrazolidones, or a combination of dihydroxybenzenes and p-aminophenol in that good performance is easily obtained. Combinations of classes are preferred. Also, ascorbic acids may be used as a substitute for hydroquinones. As the dihydroxybenzene developing agent used in the present invention, hydroquinone, chlorohydroquinone, bromohydroquinone, isopropylhydroquinone, methylhydroquinone, 2,3-dichlorohydroquinone, 2,5-dichlorohydroquinone, 2,3-dibromohydroquinone,
Although there are 2,5-dimethylhydroquinone and the like, hydroquinone is particularly preferred. Examples of the p-aminophenol-based developing agent used in the present invention include N-methyl-p-aminophenol, p-aminophenol, N- (β-hydroxyethyl) -p-aminophenol, and N- (4-hydroxyphenyl). Glycine, 2-methyl-p-aminophenol, p-benzylaminophenol and the like,
Among them, N-methyl-p-aminophenol is preferred. The 3-pyrazolidone-based developing agents used in the present invention include 1-phenyl-3-pyrazolidone and 1-phenyl-
4,4-dimethyl-3-pyrazolidone, 1-phenyl-
4-methyl-4-hydroxymethyl-3-pyrazolidone, 1-phenyl-4,4-dihydroxymethyl-3-
Pyrazolidone, 1-phenyl-5-methyl-3-pyrazolidone, 1-p-aminophenyl-4,4-dimethyl-
3-pyrazolidone, 1-p-tolyl-4,4-dimethyl-3-pyrazolidone, 1-p-tolyl-4-methyl-4
-Hydroxymethyl-3-pyrazolidone and the like. The developing agent is preferably used usually in an amount of 0.001 to 1.2 mol / l.

As the sulfite preservative used in the development,
Sodium sulfite, potassium sulfite, lithium sulfite,
Examples include ammonium sulfite, sodium bisulfite, and potassium metabisulfite. The sulfite is preferably at least 0.2 mol / l, particularly preferably at least 0.4 mol / l.
The upper limit is preferably set to 2.5 mol / liter. Also, ascorbic acid may be used as a preservative alone or in combination with another preservative. The preferred range is 0.
It is from 02 mol / liter to 0.4 mol / liter.

The pH of the developer used in the development is 8.5 to 1
2 is preferable, and more preferably pH 9 to
11 range. When the number of processed photosensitive materials is small, more stable photographic properties can be obtained by adjusting the pH of the developer to 10.0 or less. The alkaline agent used for setting the pH includes a pH adjuster such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, tribasic sodium phosphate, and tribasic potassium phosphate. JP-A-62-2
No. 186259 (borate), JP-A-60-93433
Nos. (Eg, saccharose, acetoxime, 5-sulfosalicylic acid), phosphates, carbonates, and other buffers.

Further, a hardener may be used in the developer. As the hardener, a dialdehyde-based hardener or a bisulfite adduct thereof is preferably used. Specific examples thereof include glutaraldehyde and bisulfite adduct thereof. Additives other than the above components include development inhibitors such as sodium bromide, potassium bromide, and potassium iodide: ethylene glycol, diethylene glycol, triethylene glycol, dimethylformamide, methyl cellosolve, hexylene glycol, ethanol, and methanol. Organic solvent such as: 1-phenyl-
Antifoggants such as 5-mercaptotetrazole, mercapto-based compounds such as 2-mercaptobenzimidazole-5-sulfonic acid sodium salt, indazole-based compounds such as 5-nitroindazole, and benztriazole-based compounds such as 5-methylbenztriazole. Research Disclosure Vol. 176, No. 1764
3. Development accelerators described on page XXI (December, 1978), and if necessary, a color tone agent, a surfactant,
It may contain an antifoaming agent, a water softener, an amino compound described in JP-A-56-106244, and the like.

In the developer used in the present invention, a silver stain inhibitor is disclosed in JP-A-56-24347, JP-B-62-267.
4702, JP-A-3-51844, 4-2913
No. 5, Japanese Patent Application No. 2-131736, No. 3-191288
And the silver stain inhibitor described in JP-A-3-233718 can be preferably used. Among them, a 6-membered hetero compound containing two nitrogen atoms as constituent atoms of a 6-membered ring and having at least one substituent other than a mercapto group, a hydroxy group and a hydrogen atom, and 1 to 3 or less as constituent atoms of a 5-membered ring And a 5-membered ring hetero compound having at least one mercapto group containing a nitrogen atom, and it is particularly preferable to use both in combination. In particular, Japanese Patent Application No. 3-233
No. 718, Compound Examples I-1 to I-13 and II-1 to II-II
−14. Particularly preferred silver stain inhibitors are the following compound examples a to e.

[0035]

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The developing solution is described in JP-A-56-1062.
No. 44, and an amino compound such as an alkanolamine described in EP-A-0136582 can be used.

The fixing solution is an aqueous solution containing a thiosulfate as a fixing agent, and has a pH of 3.8 or more, preferably pH 4.0.
~ 7.0. More preferably, pH 4.2-5.
5 Examples of the fixing agent include sodium thiosulfate and ammonium thiosulfate, and ammonium thiosulfate is particularly preferable from the viewpoint of fixing speed. The amount of the fixing agent can be appropriately changed, and is generally about 0.1 to about 3 mol /
Liters. Fixing agents may include water-soluble aluminum salts that act as hardeners, such as aluminum chloride, aluminum sulfate, potassium alum, and the like.

In the fixing solution, tartaric acid, citric acid, gluconic acid or a derivative thereof can be used alone or in combination of two or more. It is effective that these compounds contain 0.005 mol or more per liter of fixing solution.
01 to 0.03 mol / liter is particularly effective. The fixing solution may contain a preservative (for example, sulfite or bisulfite), a pH buffer (for example, acetic acid or boric acid), a pH adjuster (for example, sulfuric acid), a chelating agent having a water softening ability, Compounds described in JP-A-62-78551 can be included. As a method of replenishing the developer and the fixing solution, see
134666, 3-233909, 3-6725
8. The method of JP-A-2-164760 can be used.

The washing water in the present invention is a concept including not only washing water in a narrow sense but also a so-called stabilizing liquid. Japanese Patent Laid-Open No. Hei 4-37755 describes a method for supplying and draining washing water.
Is preferred. Tap water, ion-exchanged water, distilled water, etc. can be used as the rinsing water.
In addition to the contact with the anti-scaling agent, the following anti-sagging means can be applied. Japanese Patent Laid-Open No.
UV irradiation method described in JP-A-263939, ibid.
No. 3940, using a magnetic field;
No. 1632, JP-A-62-115154, and JP-A-62-153.
No. 952, No. 62-220951, No. 62-2095
A method using a bactericide described in No. 32 is applicable. LFWest. “Water Quality Criteria” P
hoto.Sci. & Eng.Vol. 9No.6 (1965), MWBeach, “Mic
robiological Growths in Motion-picture Processing "
SMPTE Journal Vol.85, (1976), RODeegan. “Phot
o.Processing WashWater Biocides "J.Imaging Tech 1
0, No. 6 (1984) and JP-A-57-8542, 5
Nos. 7-58143, 58-105145, 57-
132146, 58-18631, 57-97
No. 530, No. 57-157244 and the like can be used in combination, if necessary. In addition, the washing tank (or stabilizing tank) and the stock tank may be provided with RTKreiman as necessary.
Authors, J. Image.Tech 10, (6) p. 242 (1984), isothiazoline compounds, Research Disclosure 205
Vol., No. 20526 (May, 1981), isothiazoline compounds, Vol. 228, No. 228
No. 45 (April 1983), Japanese Patent Application Laid-Open No. 62-209532, Japanese Patent Application No.
Compounds described in JP-A-24138 and JP-A-2-269339 can be used in combination as a microbiocide. In addition, "The Chemistry of Bacterial Prevention and Protection", Hiroshi Horiguchi, Sankyo Publishing (Showa 57), "Handbook of Bacterial Control and Protection"
It may contain a compound as described in the Japan Society of Antibacterial Protection and Hakuhodo (Showa 61). Needless to say, the additive to the washing water is not limited to the above.

In the present invention, JP-A-63-1835
A squeeze roller washing tank described in No. 0 can also be provided. It is also preferable to adopt a configuration of a washing step as disclosed in JP-A-63-143548. Further, part or all of the overflow liquid from the washing tank generated by replenishing such washing water is disclosed in JP-A-60-2351.
As described in JP-A No. 33, it can also be used for a fixing solution which is a preceding processing step.

In the present invention, the term "development time" refers to the time from when the leading end of the photosensitive material to be processed is immersed in the developing solution to the time when it is immersed in the next fixing solution. The time from immersion to immersion in the next washing water (stabilizing solution), "washing time" means the time of immersion in washing water. The “drying time” refers to the time during which the photosensitive material has entered the drying section. The development time is 5 to 25 seconds,
Preferably, the development time is 6 seconds to 20 seconds, and the developing temperature is 18 seconds.
C. to 50.degree. C. are preferred, and 20.degree. Fixing temperature and time are about 18 ° C to about 50 ° C for 4 seconds to 2 seconds.
5 seconds is preferable, and 5 seconds to 20 seconds at 20 ° C to 40 ° C is more preferable. Within this range, sufficient fixing can be performed, and the sensitizing dye can be eluted to such an extent that no residual color is generated. The temperature and time for water washing (stable) are preferably 0 to 50 ° C for 2 seconds to 25 seconds, and more preferably 10 ° C to 40 ° C for 2 seconds to 20 seconds.

In the present invention, as described above, the photosensitive material that has been developed, fixed and washed is dried through a squeeze roller for squeezing the washing water.

In the present invention, when developing processing for 90 seconds or less by dry to dry, a rubber material as described in JP-A-63-151943 is used in order to prevent development unevenness peculiar to rapid processing. Or the discharge flow rate for stirring the developing solution in the developing solution tank is set to 10 m / min or more as described in JP-A-63-151944. In addition, as described in JP-A-63-264758, it is more preferable to perform stronger stirring at least during development processing than during standby.

The replenishment amounts of the developing solution and the fixing solution are four cuts (10 × 1
(2 inches) Preferably, it is 16 ml or less, more preferably 15 ml to 3 ml per sheet. In an embodiment of the present invention, the processing time is preferably 90 seconds or less, particularly preferably 70 seconds or less. The speed at which the photosensitive material is conveyed during processing by an automatic processor is 70 mm / sec or less, preferably 50 mm / sec.
Seconds to 5 mm / sec. Drying of automatic processor is about 40 ° C ~ 1
Performed at 00 ° C. The drying time can be appropriately changed depending on the surrounding conditions, but is usually about 5 seconds to 25 seconds. Drying is usually performed by a method using hot air, a far infrared heater, contact heating of a photosensitive material, or a combination of these three methods. As a general combination method, there are a combination of hot air drying and far-infrared drying, a combination of hot air drying and contact heat drying with a heat roller, and the like.

[0045]

【Example】

Example 1 (1) The following radiographic intensifying screens were prepared in pairs (for front and rear). HR-4 (commercially available from Fuji Photo Film Co., Ltd.) HR-8 (commercially available from Fuji Photo Film Co., Ltd.) Radiation intensifying screen A Radiation intensifying screen B

1) Production of Radiation Intensifying Screen A As a coating solution for forming a phosphor sheet, a phosphor (Gd ₂ O ₂
S: Tb) 200 g, Binder A (polyurethane, manufactured by Sumitomo Bayer Urethane Co., Ltd., trade name: Desmolac TPKL)
5-2625 [solid content 40%]), 20 g of binder B (nitrocellulose, nitrification degree 11.5%), and methyl ethyl ketone solvent, and dispersed with a propeller mixer to give a viscosity of 30 PS (25 ° C.). A coating solution was prepared (binder / phosphor ratio = 1/20). This was coated on a polyethylene terephthalate (temporary support, thickness 180 μm) coated with a silicone release agent to a thickness of 160 μm.
(Film thickness after pressure compression processing described later)
After drying, it was peeled off from the temporary support to form a phosphor sheet. Separately, as a coating liquid for forming an undercoat layer, 90 g of a soft acrylic resin and 50 g of nitrocellulose are added to methyl ethyl ketone, mixed and dispersed, and having a viscosity of 3 to 6 PS (25
C).

250 μm thick kneaded with titanium dioxide
Of polyethylene terephthalate (support) is horizontally placed on a glass plate, and the above-mentioned coating solution for forming an undercoat layer is uniformly applied on the support using a doctor blade, and then the temperature is gradually raised from 25 ° C to 100 ° C. And the coating film was dried to form an undercoat layer on the support (thickness of coating film:
15 μm). On this, the phosphor sheet prepared first is placed, and using a calender roll, 400 Kgw / cm ²
At a pressure of 80 ° C. Separately,
Fluorine resin (fluoroolefin / vinyl ether copolymer, manufactured by Asahi Glass Co., Ltd., trade name: Lumiflon LF10
0) 70 g, crosslinking agent (isocyanate, manufactured by Sumitomo Bayer Urethane Co., Ltd., trade name: Desmodur Z4370)
25 g, bisphenol A type epoxy resin 5 g, and alcohol-modified silicone oligomer (having a dimethylpolysiloxane skeleton, hydroxyl groups (carbinol groups) at both ends)
Having a product name, manufactured by Shin-Etsu Chemical Co., Ltd., trade name: X-2
2-2809) was added to a mixed solvent of toluene / isopropyl alcohol (1: 1, volume ratio) to prepare a coating solution for forming a protective film. The above coating liquid for forming a protective film is applied to the surface of the phosphor sheet which has been subjected to the pressure and compression operation on the support in advance using a doctor blade, and is heated at 120 ° C. for 30 minutes. Heat cured, thickness 3μ
m of the transparent protective film was formed. As described above, a radiographic intensifying screen A comprising a support, an undercoat layer, a phosphor layer, and a transparent protective film was manufactured.

2) Production of Radiation Intensifying Screen B The above radiation intensifying screen A was prepared except that the phosphor sheet was formed so that the thickness of the phosphor sheet was 230 μm (the thickness after the compression treatment). Was repeated to produce a radiographic intensifying screen B comprising a support, an undercoat layer, a phosphor layer, and a transparent protective film.

(2) Measurement of characteristics of radiographic intensifying screen 1) Measurement of X-ray absorption X-rays generated from a tungsten target tube operated at 80 KVp with three-phase power supply were converted to an aluminum plate having a thickness of 3 mm. To reach the sample radiation intensifying screen fixed at a position 200 cm from the tungsten anode of the target tube, and then the amount of X-rays transmitted through the intensifying screen is measured 50 cm after the phosphor layer of the intensifying screen. At a position using an ionizing dosimeter, and the amount of X-ray absorption was determined. Note that, as a reference, the X-ray dose at the above measurement position measured without passing through the intensifying screen was used. Table 1 shows the measured values of the X-ray absorption of each intensifying screen.

2) Measurement of Modulation Transfer Function (CTF) An MRE single-sided photosensitive material manufactured by Eastman Kodak Co. was placed in contact with an intensifying screen to be measured, and a rectangular chart for MTF measurement (made of molybdenum, thickness: 80 μm) , Spatial frequency: 0 lines / mm to 10 lines / mm). The chart was placed at a position 2 m from the X-ray tube, a photosensitive material was placed in front of the X-ray source, and then an intensifying screen was placed. The X-ray tube used was DRX-3724 manufactured by Toshiba Corporation.
HD, which uses a tungsten target, has a focal spot size of 0.6 mm × 0.6 mm, passes through a 3 mm aluminum equivalent material including an aperture, and generates X-rays. A voltage of 80 KVp was applied to the three phases by a pulse generator, and X-rays passed through a 7 cm water filter having absorption substantially equivalent to the human body were used as a light source. The photosensitive material after the photographing was processed at 35 ° C. using a roller transport type automatic developing machine (FPM-5000) manufactured by Fuji Photo Film Co., Ltd. using a developer RD III manufactured by Fuji Photo Film Co., Ltd. A dry to dry treatment was performed at a temperature of 25 ° C. for 90 seconds to prepare a measurement sample. Note that the exposure amount at the time of the X-ray photography was adjusted so that the average value of the maximum density and the minimum density after the development processing was 1.0. Next, the measurement sample was operated with a microdensitometer. At this time, the aperture profile was measured at a sampling interval of 30 μm using a slit having an operation direction of 30 μm and a vertical direction of 500 μm. This operation was repeated 20 times to calculate the average value, which was used as the concentration profile for calculating the CTF. Thereafter, the peak of the rectangular wave at each frequency of the density profile was detected, and the density contrast at each frequency was calculated. Table 1 shows values measured for the spatial frequencies of 1 line / mm and 3 lines / mm.

3) Measurement of sensitivity Using the same X-ray source as that used in the measurement of CTF, a green-sensitized MRE single-sided photosensitive material manufactured by Eastman Kodak Co., Ltd. was combined, and the X-ray exposure was determined by the distance method. To change lo
g Step exposure was performed with a width of E = 0.15. After the exposure, the photosensitive material is developed under the same conditions as in the CTF measurement,
A measurement sample was obtained. The concentration of the measurement sample was measured with visible light to obtain a characteristic curve. The sensitivity was represented by the reciprocal of the X-ray exposure amount for obtaining (Dmin + density 1.0), and the relative sensitivity was examined using the rear-side intensifying screen HR-4 as a reference ("100"). Table 1 shows the results.

[0052]

[Table 1]

(2) Photosensitive materials -X and -Y were prepared in the following manner. <Preparation of Silver Halide Emulsion> 4.0 g of silver nitrate was added to an aqueous solution of 6.2 g of gelatin (average molecular weight: 15,000) and 6.9 g of potassium bromide kept at 49 ° C. in 1 liter of water while stirring. An aqueous solution containing an aqueous solution and 5.9 g of potassium bromide was added by the double jet method in 37 seconds. Subsequently, after adding an aqueous solution containing 18.6 g of gelatin, the temperature was raised to 64 ° C. while adding an aqueous solution containing 9.8 g of silver nitrate over 22 minutes. Further, 4.2 cc of a 25% aqueous ammonia solution was added, and 10 minutes later, an aqueous solution containing 3.9 g of acetic acid was added. Subsequently, an aqueous solution of 151 g of silver nitrate and an aqueous solution of potassium bromide were added by a control double jet method over 35 minutes while maintaining the pAg at 8.8. The flow rate at this time was accelerated so that the flow rate after the end of the addition was 14 times the flow rate after the start of the addition. After completion of the addition, 45 cc of a 2N potassium thiocyanate solution was added. Thereafter, the temperature was lowered to 35 ° C., and soluble salts were removed by a sedimentation method. After raising the temperature to 40 ° C., 35 g of gelatin, 85 mg of proxel, and a thickener were added, and sodium hydroxide, potassium bromide, and an aqueous silver nitrate solution were added. pH 6.0, pAg 7.8
Was adjusted. The temperature was raised to 56 ° C., and 3 mg of sodium ethylthiosulfonate was added.
gI fine particles were added in an amount of 0.1 mol% based on the total silver amount. Thereafter, 0.04 mg of thiourea dioxide was added, 198 mg of 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene and 600 mg of Dye-1 were added.

[0054]

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After 10 minutes, 0.52 × selenium compound-I was added.
10 ⁻⁵ mol / mol Ag, sodium thiosulfate 1.03 ×
10 ^-5 mol / mol Ag, 30 mg of potassium thiocyanate,
6 mg of chloroauric acid was added and the mixture was aged for 50 minutes.

[0056]

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Thereafter, the emulsion was quenched and solidified to obtain an emulsion.
And The resulting emulsion had a total of 9 areas of the projected area of all grains.
3% consist of grains having an aspect ratio of 5 or more, the average projected area diameter of all grains having an aspect ratio of 5 or more is 0.81 μm, the standard deviation is 15%, and the average aspect ratio obtained from the aspect ratio of each grain is 6 .2.

<Preparation of silver halide emulsion> In 1 liter of water, 4.5 g of potassium bromide, 20.6 g of gelatin,
_2.5 cc of a 5% aqueous solution of thioether HO (CH ₂ ) ₂ S (CH ₂ ) ₂ S (CH ₂ ) ₂ OH was added, and 37 cc of an aqueous silver nitrate solution (silver nitrate) was stirred into a reaction vessel maintained at 60 ° C. 3343 cc of an aqueous solution containing 3.43 g), 2.97 g of potassium bromide and 0.363 g of potassium iodide were added over 37 seconds by the double jet method. Next, an aqueous solution of 0.9 g of potassium bromide was added, and the temperature was raised to 70 ° C., and 53 cc of an aqueous silver nitrate solution (4.90 g of silver nitrate) was added over 13 minutes. Where 25%
15 cc of ammonia aqueous solution
After physical ripening for 0 minutes, 14 cc of a 100% acetic acid solution was added. Subsequently, an aqueous solution of 133.3 g of silver nitrate and an aqueous solution of potassium bromide were added over 35 minutes by a control double jet method while keeping the pAg at 8.5. After the addition was completed, 15 cc of a 2N potassium thiocyanate solution was added. Thereafter, the temperature was lowered to 35 ° C., and the soluble salts were removed by a sedimentation method.
g, 2.5 g of phenoxyethanol, and a thickener, and then added with aqueous sodium hydroxide, potassium bromide, and aqueous silver nitrate.
H6.1 and pAg 8.3 were adjusted. The temperature of the emulsion thus adjusted was raised to 56 ° C.
gI fine particles were added in an amount of 0.1 mol% based on the total silver amount. Thereafter, 600 mg of Dye-1 and 10 mg of Dye-2 were added,

[0059]

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After 10 minutes, 1 × 1 sodium thiosulfate
0 ^-5 mol / mol Ag, 0.45 × 1 selenium compound -I
0 ^-5 mol / mol Ag, Thereafter was quenched and solidified and aged for 60 minutes after addition of chloroauric acid 3.0mg and thiocyanate potassium 45 mg. This is designated as emulsion-. In the obtained emulsion, 90% or more of the total projected area of all grains consisted of grains having an aspect ratio of 5 or more, and the average projected area diameter of all grains having an aspect ratio of 5 or more was 1.4 μm.
m, the standard deviation was 20%, and the average aspect ratio determined from the aspect ratio of each particle was 7.

(Preparation of double-sided light-sensitive materials -X, -Y) Preparation of "light-sensitive material -X" (Preparation of emulsion coating solution) Emulsion was prepared by adding the following chemicals per mole of silver halide to emulsion. Liquid. -2,6-bis (hydroxyamino) -4-diethylamino-1,3,5-triazine 72 mg-trimethylolpropane 9 g-dextran (average molecular weight 40,000) 18.5 g-potassium polystyrene sulfonate (average molecular weight 600,000) ) gelatin amount of 1.8 g · hydroquinone monosodium sulfonate 4.8 g · Snowtex C (Nissan chemical Co.) emulsion layer applied to 29.1 g · gelatin one side was prepared so as to be 1.6 g / m ^2. Hardener (1,2-bis (vinylsulfonylacetamido) ethane) Prepared so that the swelling ratio was 190%.

(Preparation of Coating Solution for Surface Protective Layer) A coating solution was prepared so that each component had the following coating amount.・ Gelatin 750 mg / m ²・ Sodium polyacrylate (average molecular weight 400,000) 18 mg / m ²

[0063]

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Polymethyl methacrylate (average particle size: 3.7 μm) 69 mg / m ²・ Proxel 0.5 mg / m ² (adjusted to pH 7.4 with NaOH)

(Undercoat Layer) (1) Preparation of Dye Dispersion K for Undercoat Layer The following dyes were ball-milled by the method described in JP-A-63-197943.

[0066]

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434 cc of water and 791 cc of a 6.7% aqueous solution of Triton X 200R surfactant (TX-200R; manufactured by Rohm & Haas) were placed in a 2 liter ball mill. 20 g of the dye were added to this solution. Zirconium oxide (Z
400 ml (2 mm diameter) of rO ₂ ) beads were added and the contents were ground for 4 days. After this, 160g of 12.5% gelatin
Was added. After defoaming, the ZrO ₂ beads were removed by filtration. Observation of the obtained dye dispersion revealed that the particle size of the pulverized dye was 0.37 μm. Further, dye particles having a size of 0.9 μm or more were removed by centrifugation. Thus, a dye dispersion K was obtained.

(2) Preparation of Support and Application of Undercoat Layer Corona discharge was performed on a biaxially stretched 183 μm-thick polyethylene terephthalate film, and the first undercoat liquid having the following composition was applied in an amount of 5. It was applied with a wire bar coater so as to be 1 cc / m ² and dried at 175 ° C. for 1 minute. Next, a first undercoat layer was similarly provided on the opposite surface. The polyethylene terephthalate used contained a dye having the following structure at 0.04% by weight.

[0069]

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-Budadiene-styrene copolymer latex solution (solid content: 40%, butadiene-styrene weight ratio = 31/35) 79 cc-2,4-Dichloro-6-hydroxy-s-triazine sodium salt 4% aqueous solution 20.5 Distilled water 900.5 * The following emulsifying dispersant was used in the latex solution at 0.4 wt% based on the solid content of the latex.

[0071]

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A second undercoating layer having the following composition was coated on the first undercoating layer on both sides by a wire bar coder method on each side such that the coating amount was as described below. Coated and dried at ℃. Gelatin 160 mg / m ² · Dye Dispersion K (as a dye solids) 30 Coating aids -I 8, Proxel 0.27 mat agent 2.5 (average particle size 2.5 [mu] m in polymethyl methacrylate)

[0073]

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(Preparation of photosensitive material-X) The emulsion coating solution and the surface protective layer coating solution were coated on both sides of the support prepared as described above by a simultaneous extrusion method. The amount of silver applied on one side is 1.2 g / m ² , and that on both sides is 2.4 g / m ² .

(Preparation of Sensitive Material-Y) The amount of gelatin was adjusted so that the amount of gelatin in the emulsion layer coated on one side was 2.1 g / m ² , using the emulsion in place of the emulsion used for preparing the light-sensitive material X. An emulsion coating solution was prepared in exactly the same manner as the emulsion coating solution except that the amount was adjusted. Coating was carried out on both sides by a simultaneous extrusion method using the same support as the support having an undercoat layer used for the preparation of the light-sensitive material-X, the emulsion coating solution-, and the same surface protection layer coating solution as the light-sensitive material-X. The amount of silver coated on one side is 1.6 g / m ² , and that on both sides is 3.2 g / m ² .

(Results) X-ray sensitometry was performed by combining the photosensitive materials X and Y with the radiographic intensifying screens A and B, HR-8 and HR-4 as shown in Table II (same screen on both sides). X-ray irradiation conditions Tube voltage: 70 KV Grid not used Tube current: 80 mA Time: 0.1 sec Distance: 2.2 m Wed: Use aluminum wedge Processing Developer and fixer CE-D-F1 (Fuji Photo Film ( Developing temperature 35 ° C, fixing temperature 32 ° C Developing machine CEPROS M (Fuji Photo Film Co., Ltd.)
Processing time Dry to Dry 45 seconds Sensitivity The results are shown in Table II.

[0077]

[Table 2]

The photosensitive material-X of the present invention obtained practically sufficient sensitivity by a combination of the high X-ray absorbing screens-A, B and HR-8. The highest concentration was 3.0 or more in each case. The crossover value of the photosensitive material-X was 15%. Sensitive material -Y and the screen -A, -B, many replenishment loss such as 3.2 g / m ² of course practically sufficient sensitivity can be obtained but the amount of coated silver in combination are both in the HR-8 present Does not meet the purpose of the invention.

Example 2 (Preparation of Sensitive Material-Z) A support obtained by removing the dye dispersion K from the second undercoat layer of the support with an undercoat layer used for preparing Sensitive Material-X of Example 1 was used. An emulsion layer and a surface protective layer having exactly the same composition as that of the light-sensitive material-X were coated on both sides of the support. The amount of silver applied was 2.4 g / m ^{2 on} both sides, the same as that of the light-sensitive material-X. The crossover% was 23%. Result The processing conditions are the same as in Example 1. X-ray sensitometry (exposure conditions are the same as in Example 1). The results are shown in Table III.

[0080]

[Table 3]

Phantom Practical Operation The tube voltage 120
Chest phantom was performed with KV. In the case of the photosensitive material-Z / screen A, the sharpness was insufficient and the descriptive power of details was insufficient.

Example 3 An automatic processor FPM-1300 manufactured by FUJIFILM Corporation was modified to increase the film transport speed and increase the film transport speed.
Dry to Dry 45 seconds processing was enabled at 6 mm / second. The developing temperature during processing is 35 ° C, the fixing temperature is 35 ° C, and the washing water temperature is 18.
C., the amount of washing water per minute was 3 liters, and the amount of the circulating stirring solution for the developer fixing solution was set to 15 liters / minute during development and 5 liters / minute during standby.

Processing solution <Development replenisher> Potassium hydroxide 28.0 g Sodium sulfite 75.0 Diethylenetriaminepentaacetic acid treatment 2.0 Sodium carbonate 30.0 Hydroquinone 18.0 Diethylaminoethyl-5-mercaptotetrazole 0.1 Potassium bromide 1.0 Triethylene glycol 6.0 5-Nitroindazole 0.3 Acetic acid 40.0 1-phenyl-3-pyrazolidone 3.5 Processing aid-I 0.2

[0084]

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Make up to 1 liter with water (adjust to pH 10.3 with sodium hydroxide). <Fixing solution replenisher> Ammonium thiosulfate 96.4 g Ethylenediaminetetraacetic acid disodium dihydrate 0.025 Sodium metabisulfite 22.0 Make up to 1 liter with water (pH 5.0 with sodium hydroxide)
To adjust). When the developing process was started, each tank of the automatic developing machine was filled with the following processing solution. Developing tank: A solution obtained by adding 2.5 g of potassium bromide and 3.5 g of acetic acid to 1 liter of the above-mentioned replenisher for fixing solution. The replenishing rate was set to 10 cc / 10 × 12 inches for both the developing solution and the fixing solution, and 900 photosensitive materials (X, -Y) (10 × 10
12 inches). Of the 900 sheets, 450 sheets were full-surface exposed films and 450 sheets were unexposed films. When the 900th unexposed film was examined, it was processed normally in the 900-sheet processing of the light-sensitive material-X, but in the 900-sheet processing of the light-sensitive material-Y, the undeveloped silver halide remained due to poor fixing. .

Example 4 The following developer was prepared. Developed concentrate (2.5-fold concentrated) Potassium hydroxide 43 g Sodium sulfite 100 g Potassium sulfite 126 g Diethylenetriaminepentaacetic acid 5 g Boric acid 20 g Hydroquinone 85 g 4-Hydroxymethyl-4-methyl-1-phenyl-3-pyrazolidone 15 g Diethylene glycol 30 g 5- Methylbenzotriazole 0.2 g Potassium bromide 10 g Make up to 1 liter with water (adjust to pH 10.65) The concentrated solution was diluted as follows to obtain a working solution. Developing concentrated solution 400 ml + water 600 ml = working solution (adjusting to pH 10.35) Based on this developing solution, developing solutions as shown in Table-IV were prepared.

[0087]

[Table 4]

The same modified FPM-1300 as in Example 3
A running test was carried out using the test sample to examine the degree of silver stain generation. The fixing solution used was RF-10 manufactured by FUJIFILM Corporation. The processing conditions are the same as in the third embodiment. A tube voltage of 12 was used in exactly the same manner as in Example 2 using the combination of the photosensitive material-X / screen A for which phantom practice was performed in Example 2.
Sensitive material-X, which had a chest phantom practice at 0 KV, was run. The running conditions were as follows. Sensitive material -X (10 inches x 12 inches) that performed chest phantom practice per day 2
Process 100 sheets, rest it for 3 days, and rest for 4 days (this 4
During the day off, silver stains are more likely to occur than during operation, which is about three times worse than normal running. ) Was performed as one round, and a total of five rounds were performed. 1 refill
Developing and fixing liquid are 10 cc per 0 inch × 12 inch. Here, the normal running refers to running for one day off with six days of operation. The running results were as shown in Table V, and it was found that the use of the compound of the present invention had a high ability to prevent silver staining.

[0089]

[Table 5]

Example 5 A developer 10 was prepared by reducing the amount of potassium hydroxide from the developer -5 of Example 4 so that the pH of the used solution was 9.7. Developing solution-5 was prepared using the same modified FPM-1300 as in Example 4.
ry to Dry 45 seconds treatment, developer-10 is FPM-130
No. 0 was modified and subjected to a dry-to-dry 70-second treatment. The temperature of the developer and fixer is 35 ° C. and the temperature of the washing water is 18
The replenishing rate is 10 cc / 10 × 12 inches for both development and fixing. The fixing solution has the same RF-10 as that of Example 4. After performing X-ray exposure with the combination of photosensitive material-X / screen A under the same X-ray irradiation conditions as in Example-1, fresh developing solutions -5 and -10 were prepared, and 30 sheets of each developing solution were prepared ( The size was 10 × 12 inches). 30 each
The photographic performance of the first photograph was examined. Thereafter, 30 sheets were processed with each developer under the same conditions for 14 days. Day 14 30
The photographic performance of the first photograph was examined. The results are shown in Table VI.
It can be seen that the developer 10 has a small change in sensitivity due to the running process.

[0091]

[Table 6]

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ identification code FI G03C 5/29 G03C 5/29 (58) Investigated field (Int.Cl. ⁷ , DB name) G03C 5/17 G03C 5/29 G03C 1/00

Claims (4)

(57) [Claims] 1. A radiation image forming assembly for X-ray exposure wherein a photosensitive material is loaded between two radiation screens, wherein said photosensitive material comprises radiation-sensitive silver halide particles on both surfaces of a transparent support. At least one emulsion layer has at least 60% of the total projection area of silver halide grains having an average aspect ratio of 5 or more and a projection area corresponding to all grains having an aspect ratio of 5 or more. It is composed of tabular grains having an average diameter of 1.0 μm or less, the coated silver amount per side is 1.4 g / m ² or less, and light emitted from a radiation intensifying screen disposed on the front side of a silver halide photographic material. A light-sensitive material having a crossover value of 19% or less, which is radiated to a rear photosensitive layer of the silver halide photographic material, wherein at least one of the two radiation screens is an X-ray Radiographic imaging assembly characterized by Energy is a radiation intensifying screen which absorbs the amount of 28% or more with respect to X-rays of 80 KVp. 2. A developing solution per 4 pieces (10 × 12 inches) of a silver halide photographic light-sensitive material constituting the radiation image forming assembly according to claim 1 using a roller transport type automatic developing machine. And the replenishment amount of the fixer is 16 ml or less, respectively.
A method for processing a silver halide photographic material, wherein the processing is performed for 90 seconds or less. 3. The silver halide photographic light-sensitive material constituting the radiation image forming assembly according to claim 1, wherein the silver halide photographic light-sensitive material contains two nitrogen atoms as constituent atoms of a 6-membered ring and is other than a mercapto group, a hydroxy group and a hydrogen atom 6 having at least one substituent
Halogenation characterized by processing with a developing solution containing a 5-membered heterocyclic compound and a 5-membered heterocyclic compound containing at least one and no more than 3 nitrogen atoms as constituent atoms of a 5-membered ring and having at least one mercapto group. Processing method of silver photographic photosensitive material. 4. The method for processing a silver halide photographic material according to claim 3, wherein the processing is performed with a developer having a pH of 10 or less.