JP2001159803A - Silver halide photographic sensitive material and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a silver halide photographic sensitive material for X-ray mammography excellent in sharpness and free from sticking and defective conveyance and an X-ray image forming method using the sensitive material. SOLUTION: The silver halide photographic sensitive material has at least one photosensitive silver halide emulsion layer on one face of the substrate and a backing layer on the other face. The matting degree of the emulsion layer side of the sensitive material is 133-5,320 Pa and that of the backing layer side is 13,300-39,900 Pa. The backing layer has a solid dispersed antihalation dye layer, a middle layer containing polymer particles having 2-10 μm average particle diameter and <=10% relative standard deviation and an outermost layer not substantially containing such polymer particles, in this order from the substrate side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a silver halide photographic material having a light-sensitive silver halide emulsion layer on one side of a support and a backing layer on the other side. In particular, a silver halide photographic light-sensitive material for single-sided exposure for medical use (hereinafter, also referred to as "photographic light-sensitive material" or simply as "light-sensitive material")
It is about.

[0002]

2. Description of the Related Art In recent years, it has been found from the survey of disease trends in Japan that the number of cases of breast cancer is increasing, and early detection of breast cancer in health examinations has become an important issue. Conventionally, breast cancer screening includes visual inspection, palpation, ultrasonic image diagnosis, X-ray mammography (mammography), and the like.
The importance of mammography is increasing due to its diagnostic effectiveness. In X-ray mammography, since the subject contrast is originally low, a source having a low tube voltage (40 kVp or less) having a high X-ray absorption is used. However, the image to be diagnosed is still often a tumor shadow or the like having only a slight contrast, and there is a difficulty in finding an early-stage cancer in particular. Further, microcalcified images having a size of several hundred μm are also important for the diagnosis of breast cancer, and it is necessary to accurately read their morphology. Therefore, a high sharpness is required for a mammography imaging system. Therefore, as a screen / film, a single screen and a single-sided film having a silver halide emulsion surface arranged in close contact with the phosphor surface thereof Is usually used.

[0003] On the other hand, various kinds of automation have been performed in order to enhance the work efficiency of group examinations and the like. For example, an auto feeder that automatically supplies a photographed sheet film to an automatic developing machine, a photographed film from an X-ray mono-cassette, and the like. A receiving supplier that automatically performs a series of operations to take out unexposed film into the cassette, a conveyor system that transports a sheet film from a shooting room to an automatic processor by a conveyor, and an X-ray intensifying screen fixed at a shooting position On the other hand, films have been transported at a high speed, such as a changer for automatically exchanging photographed and unexposed sheet films. In addition, as a result of the improvement of the processing speed of the automatic developing machine, Dr.
Ultra-rapid processing of 45 seconds or less in y to Dry has become widespread. Along with these automation and high-speed conveyance, there is a strong demand for photosensitive materials that are free from cracks and have good transportability.

[0004] Poor transport is caused when the film is repeatedly pressed, peeled off, and slid between the transport roller and the material of each part and becomes charged and adheres electrostatically, or the matting agent in the film comes off. As a result of adhering and accumulating on the suction cup for conveyance, the suction cup may not be adsorbed on the film, which may occur. In the former case, various antistatic techniques have been proposed and can be referred to.

[0005] Further, under conditions of high humidity, films tend to stick together, and a plurality of films are simultaneously conveyed and film clogging is likely to occur. With respect to such dustiness, a method of adding a matting agent to a film, a method of adding a fluorine-based surfactant, and the like are known. However, if the matting agent is used to improve the tightness, the abrasion resistance deteriorates,
The conveyance failure due to the peeling of the matting agent occurs.

In a single-sided film, when a large amount of a matting agent is added to the side having a silver halide emulsion layer, the matting agent grains sink into the silver halide emulsion layer, and the silver halide grains are displaced. As a result, the portion is liable to cause a failure called starry night, which causes a decrease in concentration. By reducing the amount of the matting agent on the side of the silver halide emulsion layer and using a large amount of the matting agent on the side of the backing layer, it is possible to prevent stickiness between the films, but the matting agent tends to peel off from the backing layer. On the other hand, when a large amount of the fluorine-based surfactant is used, a spot-like processing failure or processing unevenness may occur due to the adhesion of the surfactant accumulated in the processing solution to the film.

Further, a photosensitive material for ultra-rapid processing of 45 seconds or less is required to have excellent development progress, fixation progress, drying property and the like. Particularly, considering the drying property of the backing layer, it is most effective to reduce the amount of moisture brought in. As a means for achieving this, the amount of hydrophilic colloid such as gelatin is reduced, and the amount of swelling of hydrophilic colloid is reduced. There is a method of increasing the amount of a hardener in order to reduce the amount. However, reducing the amount of swelling by using a large amount of a hardening agent makes it difficult to remove the antihalation dye and causes problems such as residual color due to the residual dye.
On the other hand, a decrease in the amount of the hydrophilic colloid tends to cause deterioration in abrasion resistance and poor transport due to peeling of the matting agent.

[0008]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a silver halide photographic material for X-ray mammography which has excellent sharpness, does not cause crackling, and has poor transport, and an X-ray material using the same.
An object of the present invention is to provide a line image forming method.

[0009]

The object of the present invention has been attained by the following.

In a silver halide photographic material having at least one photosensitive silver halide emulsion layer on one side of a support and a backing layer on the opposite side, the photosensitive silver halide emulsion layer The matt degree of the side having is 133
The matting degree on the side having the backing layer is 13300 to 39900 Pa, and the backing layer is a solid-dispersed antihalation dye layer from the side close to the support, and has an average particle size of 2 to 10 μm. A silver halide photographic material having an intermediate layer containing polymer particles having a standard deviation of 10% or less and an outermost layer containing substantially no polymer particles.

In a silver halide photographic material having at least one photosensitive silver halide emulsion layer on one side of a support and a backing layer on the other side, the photosensitive silver halide emulsion layer The matt degree of the side having is 133
5300 Pa, the matting degree on the side having the backing layer is 13300 to 39900 Pa, and the backing layer is an antihalation dye layer solid-dispersed from the side close to the support, having an average particle size of 2 to 10 μm and 5 ~ 15
A silver halide photographic light-sensitive material having an intermediate layer containing polymer particles containing mol% of an acidic monomer and an outermost layer substantially not containing the polymer particles.

The silver halide photographic material as described in the above item, wherein the polymer particles are spherical polymer particles.

The silver halide photographic material as described in the above item, wherein the polymer particles have a relative standard deviation of 10% or less.

A surface having a phosphor layer of an X-ray fluorescent intensifying screen is brought into close contact with a surface having a photosensitive silver halide emulsion layer of the silver halide photographic light-sensitive material described in any one of the above, and is transmitted through a subject. An image forming method for forming an X-ray image by irradiating the obtained X-rays and then developing, fixing, washing and drying with an automatic developing machine.

[0015] The image forming method according to [1], wherein the X-ray has a tube voltage of 40 kVp or less. The silver halide photographic material according to any one of the above items, which is for X-ray mammography.

[0016] An image forming method as described in or for X-ray mammography. Hereinafter, the present invention will be described in detail.

First, the polymer particles according to claim 1 of the present invention will be described. The polymer particles of the present invention have an average particle size of 1 to 10 μm and a relative standard deviation of 10% or less. Here, the average particle diameter is a number average particle diameter, and the relative standard deviation is a value obtained by dividing the standard deviation of the particle diameter of the polymer particles by the average particle diameter.

The average particle size of these polymer particles is preferably 2 to 9 μm, more preferably 3 to 8 μm. When the average particle size is smaller than 1 μm, the effect of preventing dustiness is reduced, and when the average particle size is larger than 10 μm, peeling is liable to occur and abrasion resistance is deteriorated. Further, the relative standard deviation is preferably 8% or less, more preferably 7% or less. If the relative standard deviation is too large, coarse particles are mixed and peeling easily occurs.
The average particle diameter and the relative standard deviation in the present invention can be determined by taking an electron micrograph of polymer particles and randomly measuring 500 or more particle diameters from the photograph.

The content at the backing layer side of the polymer particles is preferably from 50 to 600 mg / m ² · sided, more preferably 80~400mg / m ² · sided, particularly preferably 100 to 300 mg / m ² · One side.
0.5 to 60 mg when used on the silver halide emulsion layer side
/ M ² · one side, preferably 5 to 40 m
g / m ² · one side is preferred.

The glass transition point (Tg) of the polymer compound used as the polymer particles is preferably 40 ° C. or higher. Among them, Tg is preferably 50 ° C. or higher, more preferably 60 ° C. or higher. If the Tg is less than 40 ° C., the blocking property in an environment at an air temperature of 40 ° C. or more deteriorates, which is not preferable.

The refractive index of the polymer particles is preferably close to the refractive index of the binder in the layer containing the polymer particles, preferably within ± 0.5, more preferably within ± 0.3 of the binder. , More preferably within ± 0.1. When the refractive index of the polymer particles is out of the range of ± 0.5 with respect to the refractive index of the binder of the layer containing the polymer particles, it becomes a factor of deteriorating the transparency.

The polymer particles may be used as a mixture of two or more kinds. Further, the polymer particles of the present invention are preferably spherical, and when the diameter of the polymer particles is measured using an electron micrograph, the ratio of the major axis / minor axis in the same particle is usually 1.2 or less, preferably Is 1.1 or less.

As the polymer particles, a polymer compound synthesized by a seed polymerization method, a soap-free polymerization method, a suspension polymerization method, or a spherical polymer compound formed by a spray drying method or a dispersion method can be used. Among them, the seed polymerization method is preferable, and the method described in JP-A-8-120005 is particularly preferable.

In order to polymerize a monomer onto a seed particle by a seed polymerization method, a monomer, a polymerization initiator and an emulsifier are charged into an aqueous medium to emulsify, and the seed particle is charged into the emulsion to perform polymerization. Let it.

The seed particles can be formed of various resins. Specific examples of the resin forming the seed particles include a (meth) acrylic resin, a styrene resin, a mixed resin of a (meth) acrylic resin and a styrene resin, or a (meth) acrylic monomer and styrene. A copolymer with a system monomer can be mentioned. Further, the (meth) acrylic resin or the styrene resin includes, as described above, another monomer copolymerizable with the (meth) acrylate ester monomer and / or the styrene monomer. May be copolymerized. Examples of such a monomer include a vinyl monomer and an unsaturated carboxylic acid monomer.

As the (meth) acrylic resin, a (co) polymer of (meth) acrylate or (meth) acrylate
It is preferably a copolymer of an acrylic ester monomer and another monomer. Examples of (meth) acrylate monomers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, Lauryl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-propyl (meth) acrylate, chloro-2-hydroxyethyl (meth) acrylate, diethylene glycol mono Examples thereof include (meth) acrylate, methoxyethyl (meth) acrylate, glycidyl (meth) acrylate, dicyclopentanyl (meth) acrylate, and dicyclopentenyl (meth) acrylate.

Examples of the styrene monomer forming the seed particles include styrene, methylstyrene, di- or trimethylstyrene, ethylstyrene, di- or triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene. And styrene such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene and chloromethylstyrene; and nitrostyrene, acetylstyrene and methoxystyrene.

The seed particles may contain, for example, (meth) acrylic acid ester in an amount of usually 0 to 100 parts by mass, preferably 50 to 100 parts by mass.
100 parts by weight, usually 0 to 80 parts by weight, preferably 0 to 50 parts by weight of a styrene monomer, and 0 to 80 parts by weight, preferably 0 to 80 parts by weight of another monomer such as a vinyl monomer. ~ 50
It can be copolymerized in parts by weight.

The seed particles preferably used in the present invention have a crosslinked structure. The gel fraction of the seed particles by the toluene extraction method is in the range of 10 to 85%, and more preferably 30 to 70%. Is preferably within the range.

To adjust the gel fraction of the seed particles,
A crosslinked structure is formed using a functional or polyfunctional monomer. Examples of these monomers include ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and pentaerythritol tri (meth) acrylate.
Examples include acrylate, 1,1,1-trishydroxymethylethane diacrylate, 1,1,1-trishydroxymethylethane triacrylate, 1,1,1-trishydroxymethylpropane triacrylate, and divinylbenzene.

In forming the seed particles, the bifunctional monomer or the polyfunctional monomer is usually used in an amount of 0.005 to 0.05 part by mass, preferably 100 to 0.05 part by mass, per 100 parts by mass of the monomer. Is used in an amount of 0.01 to 0.04 parts by mass.

The seed particles can be prepared by various methods such as soap-free emulsion polymerization, suspension polymerization and emulsion polymerization. In the present invention, soap-free emulsion polymerization is particularly preferred.

Examples of the polymerization initiator used in the soap-free emulsion polymerization include persulfates such as potassium persulfate and ammonium persulfate. The polymerization initiator soluble in the aqueous medium used in the polymerization is used. It is not limited to these as long as it is an initiator. The polymerization initiator is usually used in an amount of 0.1 to 10 parts by mass based on 100 parts by mass of the monomer used.

The seed particles thus formed are usually 0.05 to 1 μm, preferably 0.2 to 0.6 μm.
Average particle size. The relative standard deviation of the particle size is usually 10% or less, preferably 5% or less.

The next polymerization step is usually carried out by blending seed particles, a monomer and a polymerization initiator, and if necessary, an emulsifier and a dispersion stabilizer in an aqueous medium. The monomer used in this polymerization step is the monomer listed in the description of the production of the seed particles, and may be the same as or different from the monomer that formed the seed particles.

Examples of the polymerization initiator used in the seed polymerization include persulfates such as potassium persulfate and ammonium persulfate; peroxides such as benzoyl peroxide and lauryl peroxide;
An azo compound such as azobisisobutyronitrile can be used. The polymerization initiator is usually used in an amount of 0.1 to 10 parts by mass based on 100 parts by mass of the monomer.

Examples of the emulsifier include alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate, and polyethylene glycol alkyl ethers such as polyethylene glycol nonylphenyl ether. The emulsifier is usually used in an amount of 0.1 to 5 parts by mass based on 100 parts by mass of the monomer.

Examples of dispersion stabilizers include partially saponified polyvinyl alcohol, polyvinyl alcohol, poly (meth) acrylic acid, copolymers thereof, and neutralized products thereof. The dispersion stabilizer is usually used in an amount of 0.1 to 5 parts by mass with respect to 100 parts by mass of the monomer.

Through the above polymerization step,
The monomers absorbed by the seed particles polymerize and the seed particles grow. Usually, the polymerization of the second and subsequent stages is performed so as to be 2 to 100 times the mass of the seed particles. The second and subsequent polymerization steps are usually repeated 1 to 10 times, preferably 1 to 5 times. In the final stage, the particles produced in the polymerization step immediately before being used as seed particles have a crosslinked structure, and the seed particles have a gel fraction of 10 to 85% by a toluene extraction method. Use
Further, the gel fraction is preferably in the range of 30 to 70%.

In order to adjust the gel fraction of the seed particles in the final stage, a bifunctional or polyfunctional monomer can be used as in the case of the seed particles in the first stage.

A production example of the polymer particles (P-1) of the present invention is shown (in the production examples, “parts” represents “parts by mass”). (Preparation of Seed Particles) In a four-neck flask having a capacity of 1 liter equipped with a thermometer and a nitrogen inlet tube, 100 parts of methyl methacrylate as a monomer, and 0.04 of ethylene glycol dimethacrylate as a crosslinkable monomer. And 900 parts of ion-exchanged water were added and mixed, and the temperature was raised to 80 ° C. while stirring under a nitrogen stream. Next, 0.2 parts of potassium persulfate was dissolved in 5 parts of ion-exchanged water, and added to the reaction solution in the four-necked flask.
The reaction was carried out for a time to obtain a dispersion of seed particles.

Observation with an electron microscope photograph revealed that the particle diameter of the seed particles was 0.50 μm and the standard deviation was 0.5 μm.
03 μm. The gel fraction obtained by the toluene extraction method was 80%. (Second Stage Polymerization) In a device similar to the above, 0.03 part of ethylene glycol dimethacrylate and 0.2 part of benzoyl peroxide were charged as crosslinkable monomers to 100 parts of methyl methacrylate as a monomer. And 1 part of sodium dodecylbenzenesulfonate and 88 parts of
After mixing with 900 parts of ion-exchanged water in which 1 part of% saponified polyvinyl alcohol was dissolved, the mixture was mixed for 30 minutes under strong stirring.

Next, 33 parts of the above-mentioned seed particle dispersion was added to the above mixture, and the mixture was gently stirred at 40 ° C. for 30 minutes and reacted at 80 ° C. for 6 hours to obtain a dispersion of polymer particles. .

The average particle size of the obtained polymer particles is 1.2.
0 μm with a standard deviation of 0.05 μm. or,
The gel fraction obtained by the toluene extraction method was 60%. (Third-stage polymerization) Next, 95 parts of methyl methacrylate as a monomer, 5 parts of ethylene glycol dimethacrylate and 0.2 part of benzoyl peroxide were mixed and dissolved in a similar apparatus. The solution was mixed with 900 parts of ion-exchanged water in which 1 part of sodium dodecylbenzenesulfonate and 1 part of 88% saponified polyvinyl alcohol were dissolved, and then mixed with vigorous stirring for 30 minutes.

Next, 20 parts of the seed emulsion obtained in the second stage was added to this mixture, and the mixture was gently stirred at 40 ° C. for 30 minutes, followed by a reaction at 80 ° C. for 6 hours to disperse the polymer particles. A liquid was obtained.

Observation with an electron microscope photograph revealed that the particles were truly spherical monodisperse particles having an average particle diameter of 4.4 μm and a standard deviation of 0.20 μm, and a relative standard deviation of 4.5%.

Next, the polymer particles according to claim 2 of the present invention will be described. The polymer particles have an average particle size of 1
It is a copolymer having a particle size of 10 to 10 μm and comprising 5 to 15% of an acidic monomer and at least one or more nonionic monomers. The average particle diameter and the relative standard deviation mentioned here are the same as those described for the polymer particles according to the first aspect. The average particle size of the polymer particles is preferably 2 to 9 μm.
m, more preferably 3 to 8 μm.

Examples of the acidic monomer include acrylic acid, methacrylic acid, itaconic acid, maleic acid, styrenesulfonic acid, vinylbenzylsulfonic acid, vinylsulfonic acid, acryloyloxyalkylsulfonic acid (acryloyloxymethylsulfonic acid, etc.), methacryloyloxyalkyl Sulfonic acid (such as methacryloyloxyethylsulfonic acid), acrylamidoalkylsulfonic acid (such as 2-acrylamido-2-methylethanesulfonic acid), methacrylamidoalkylsulfonic acid (such as 2-methacrylamido-2-methylethanesulfonic acid), and acryloyl Oxyalkyl phosphates (such as acryloyloxyethyl phosphate) are exemplified. These acids may be salts of alkali metals (sodium, potassium, etc.) or ammonium ions. Acrylic acid and methacrylic acid are preferred, and methacrylic acid is particularly preferred.

The content of the acidic monomer is 5 to 15 mol%, preferably 7 to 12 mol% of the total monomer components. If the content of the acid component is more than 15 mol%, it will be dissolved at the time of development processing, and if it is less than 5 mol%, it will be easily peeled off.

Examples of the nonionic monomer copolymerized with the acidic monomer include (meth) acrylic acid ester, itaconic acid diester, crotonic acid ester, maleic acid diester, and phthalic acid diester. , Methyl, ethyl, propyl, i-propyl, butyl, hexyl, 2-ethylhexyl, 2-chloroethyl, cyanoethyl, 2-acetoxyethyl, dimethylaminoethyl, benzyl, cyclohexyl, furfuryl, phenyl, 2-hydroxyethyl, 2-ethoxy Ethyl, glycidyl, ω-methoxypolyethyleneoxy and the like. In addition, vinyl esters, olefins, styrenes, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl ketones, vinyl heterocyclic compounds, unsaturated nitriles and the like are also used. Further, monoalkyl itaconate (monoethyl itaconate, etc.), monoalkyl maleate (monomethyl maleate, etc.), and N- (2-acetoacetoxyethyl) acrylamide, N- (2- (2
-Acetoacetoxyethoxy) ethyl) acrylamide, divinylbenzene, ethylene glycol dimethacrylate and the like. In these monomers,
(Meth) acrylates, vinyl esters, styrenes, and olefins are preferably used, and particularly preferred are methyl methacrylate and ethyl methacrylate. Also, JP-A Nos. 62-14647 and 62-1
Particles having a fluorine atom or a silicon atom as described in JP-A Nos. 7744 and 62-17743 may be used.

Particularly preferred among the polymer particles of the present invention are those containing (meth) acrylic acid and esters thereof in an amount of 80% by mass or more in terms of the composition of the polymer particles.
In that case, vinyl esters, olefins, styrenes, acrylamides, methacrylamides, allyl compounds, vinyl ethers at a mass ratio of 20% by mass or less,
Vinyl ketones, vinyl heterocyclic compounds, unsaturated nitriles and the like are used. Preferred are styrene and styrene derivatives. As a preferred embodiment of the polymer particles,
Methyl methacrylate / acrylic acid copolymer (95/5 to 5
85/15 (molar ratio)), methyl methacrylate / methacrylic acid copolymer (95/5 to 85/15 (molar ratio)),
Ethyl methacrylate / methacrylic acid copolymer (95/5
-85/15 (molar ratio)), and more preferably, methyl methacrylate / acrylic acid copolymer (93 / 7-8).
8/12 (molar ratio)), methyl methacrylate / methacrylic acid copolymer (93/7 to 88/12 (molar ratio)), and ethyl methacrylate / methacrylic acid copolymer (93/7
８８88/12 (molar ratio)).

5 to 15% of the acidic monomer and at least 1
The polymer particles of the present invention, which are copolymers of at least one kind of nonionic monomer, are preferably monodisperse, and preferably have a relative standard deviation of 30% or less, more preferably 20% or less.

After polymerization, the polymer particles may be classified and monodispersed. As a classification means, a centrifugal separation method can be used. That is, diluting the dispersion of polymer particles,
The particles are set in a centrifuge and settled out according to the rotation speed of the centrifuge. By repeating this operation several times, the monodispersity can be improved. Examples of the monodispersion by polymerization include soap-free polymerization, suspension polymerization, seed polymerization, molecular diffusion, two-stage swelling, dynamic swelling, accelerated diffusion polymerization, and dispersion polymerization. For example, a known method is used.

Hereinafter, specific examples of the polymer particles of the present invention will be described (these are classified by centrifugation).

Composition ratio Average particle size Relative standard deviation (μm) (%) P-2 MMA: AA (90:10) 4.5 30 P-3 MMA: MAA (90:10) 4.5 20 P- 4 EMA: AA (85:15) 4.6 30 P-5 MMA: AA (95: 5) 4.5 20 P-6 EMA: MAA (90:10) 4.4 20 where MMA = methyl methacrylate , EMA = ethyl methacrylate, AA = acrylic acid, MAA = methacrylic acid.

The matting degree of the light-sensitive material of the present invention is 133 to 5320 Pa on the side having the silver halide emulsion layer.
(1.0 to 40 mmHg), preferably 655
２６2660 Pa (5.0 to 20 mmHg). or,
The matting degree on the backing layer side is 13300 to 399.
00 Pa (100 to 300 mmHg), preferably 17290 to 30590 Pa (130 to 230 mmHg).
g).

If the matte degree on the side having the silver halide emulsion layer is smaller than 13.3 Pa (0.1 mmHg), the powder tends to crack and is easily scratched. On the other hand, 5320 Pa
If it is larger than (40 mmHg), a starry night failure is likely to occur.

In the present invention, the term "mat degree" refers to a value obtained by expressing, as a change in pressure, the amount of air inflow that varies depending on the smoothness (mat degree) of the film surface using a vacuum air micrometer. 48% RH (relative humidity)
The vacuum pressure is measured under the same conditions for an unexposed photosensitive material (so-called raw film) that has been subjected to humidity control for 3 hours under the above conditions, and the numerical value expressed in Pa is referred to. The larger the value, the higher the matte degree. In the examples described below, the suction pressure was measured using a smoother (manufactured by Toei Electronics Co., Ltd.).

A known matting agent can be used to adjust the degree of matting on the side of the silver halide emulsion layer, but is preferably a method using only the polymer particles according to the present invention.
For adjusting the matte degree on the backing layer side, the polymer particles according to the present invention are mainly used, but other matting agents may be partially used. Preferably, a method using only the polymer particles according to the present invention is used.

As a known matting agent that can be used on the silver halide emulsion layer side or a matting agent that can be used in combination with the matting agent according to the present invention on the backing layer side, specifically, a water-insoluble organic or Fine particles of an inorganic compound may be used.

Examples of the organic compound include water-dispersible vinyl polymers such as polymethyl (meth) acrylate, polyacrylonitrile, acrylonitrile-α-methylstyrene copolymer, polystyrene, styrene-divinylbenzene copolymer, and polyvinyl acetate. , Polyethylene carbonate, polytetrafluoroethylene, etc .; examples of cellulose derivatives such as methyl cellulose, ethyl cellulose, cellulose acetate, cellulose acetate propionate; examples of starch derivatives such as carboxy starch, carboxydinitrophenyl starch, urea-formaldehyde-starch reactants, etc. A gelatin hardened with a known hardener, hardened gelatin obtained by coacervate hardening into microcapsule hollow particles, and the like can be preferably used.

Examples of inorganic compounds include silicon dioxide, titanium dioxide, magnesium dioxide, aluminum oxide,
Barium sulfate, calcium carbonate, silver chloride desensitized by a known method, silver bromide, glass, diatomaceous earth and the like can be preferably used.

The polymer particles on the backing layer side in the present invention are located below the outermost layer and are contained above the antihalation dye layer. Preferably the content in the backing layer side of said polymer particles is 50 to 600 mg / m ^2, more preferably 80~400mg / m ^2, particularly preferably 100 to 300 mg / m ^2. When used on the silver halide emulsion layer side, 0.5 to 60 mg / m ^2.
One side is preferred, and more preferably 5 to 40 mg / m ² · one side.

The desired matte degree obtained by using the polymer particles of the present invention is large when the polymer particles having a small average particle size are used, and small when the polymer particles having a large average particle size are used. I can do it. Also, when applying and drying,
The pressure from the conveying roller or the like may cause deformation such as sinking or crushing of the polymer particles, and the amount is adjusted to an optimum amount according to manufacturing conditions.

The outermost layer of the backing layer of the light-sensitive material of the present invention does not substantially contain the polymer particles, but the term "substantially free" means a content of less than 1 mg / m ² .

In the present invention, a layer containing a solid-dispersed antihalation dye is provided on the side of the backing layer close to the support. The antihalation dye can be decolorized and / or flowed out during the development process to obtain a photosensitive material with less residual color. As the dye to be used, a dye that can improve sharpness by absorbing a desired wavelength and removing the influence of the wavelength can be appropriately selected depending on the photosensitive material. The dyes preferably used are substantially insoluble in water at pH 7 or lower and substantially water-soluble at pH 8 or higher.

The term "solid dispersion" as used in the present invention means that the dye does not exist in a molecular state in the light-sensitive material, but is dispersed and exists as a solid having a size that cannot be substantially diffused in the layer. In practice, the dye is placed in a ball mill container, dispersed in a ball mill together with a surfactant and zirconium oxide beads, and then stabilized by adding an aqueous gelatin solution to obtain a dye dispersion. As a dispersing method, for example, a method described in JP-A-63-197943 may be used.

The particle size of the solid disperse dye used may be 0.3 μm or less, preferably 0.1 μm or less. Further, a needle-shaped type may be used. The amount of the dye is not particularly limited, but is usually 5 to 5 per m ² of the light-sensitive material.
The dose may be 300 mg, preferably 50-300 mg.

The dye used in the present invention has a maximum absorption wavelength of 5
Preferably selected from dyes between 20 and 560 nm, for example cyanine, merocyanine, oxonol,
Examples include (poly) methine dyes including hemioxonol, styryl, and arylidene dyes. Specific compounds include, for example, the compounds I described in JP-A-2-264936.
-1 to 16, II-1 to 3, III-1 to 21, IV-1 to 1
1 or 1 / O to 2 described in JP-A-1-172828.
/ O, 1 / A to 23 / A.

The compound preferably used as a solid disperse dye in the present invention can be represented by the following general formula (I).

[0071]

Embedded image

In the formula, R ₁ represents a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group, and R ₂ represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an alkoxycarbonyl group,
An aryloxycarbonyl group, a carbamoyl group, an acylamino group, an ureido group, an amino group, an acyl group, an alkoxy group, an aryloxy group, a hydroxyl group, a carboxyl group, a cyano group, a sulfamoyl group or a sulfonamide group; Represents a 6-membered oxygen-containing heterocyclic group or a 6-membered nitrogen-containing heterocyclic group, L _{1 to} L ₃ each represent a methine group, and n represents 0 or 1.

However, the compound of the formula (I) has at least one water-soluble group selected from a carboxyl group, a sulfonamide group and a sulfamoyl group.

The alkyl group represented by R ₁ and R ₂ includes, for example, methyl, ethyl, propyl, i-propyl,
groups such as t-butyl, pentyl, hexyl, octyl, 2-ethylhexyl, dodecyl, pendadecyl, eicosyl and the like. These alkyl groups include those having substituents, such as halogen atoms (chlorine, bromine, iodine, fluorine, etc.), aryl groups (phenyl, naphthyl, etc.), cycloalkyl groups (cyclopentyl, cyclohexyl, etc.), Ring groups (pyrrolidyl, pyridyl, furyl,
Thienyl), sulfinic acid, carboxyl, nitro, hydroxyl, mercapto, amino (amino, methylamino, diethylamino, etc.), alkoxy (methoxy, ethoxy, butoxy, i-propoxy, etc.), aryloxy (Phenoxy, naphthyloxy, etc.), carbamoyl group (aminocarbamoyl, methylcarbamoyl, pentylcarbamoyl, phenylcarbamoyl, etc.), amide group (methylamide, benzamide, octylamide, etc.), aminosulfonylamino group (aminosulfonylamino, methylaminosulfonylamino) , Anilinosulfonylamino, etc.), sulfamoyl groups (sulfamoyl, methylsulfamoyl, phenylsulfamoyl, butylsulfamoyl, etc.), sulfonamide groups (methanesulfonamido, etc.) , Heptane sulfonamide, benzene sulfonamide), sulfinyl group (methylsulfinyl, ethylsulfinyl, phenylsulfinyl, alkylsulfinyl groups such as octyl sulfinyl, etc. arylsulfinyl group such as phenylsulfinyl), an alkoxycarbonyl group (methoxycarbonyl,
Ethoxycarbonyl, 2-hydroxyethoxycarbonyl, octyloxycarbonyl, etc.), aryloxycarbonyl group (phenoxycarbonyl, naphthoxycarbonyl, etc.), alkylthio group (methylthio, ethylthio,
Hexylthio, etc.), arylthio group (phenylthio, naphthylthio, etc.), alkylcarbonyl group (acetyl, ethylcarbonyl, butylcarbonyl, octylcarbonyl, etc.), arylcarbonyl group (benzoyl, p-methanesulfonamidobenzoyl, p-carboxybenzoyl, naphthoyl, etc.) ), A cyano group, a ureido group (such as methylureide and phenylureide), and a thioureido group (such as methylthioureide and phenylthioureide).

The aryl group represented by R ₁ and R ₂ includes, for example, phenyl and naphthyl groups. The aryl group includes those having a substituent, and as the substituent,
Examples of the alkyl group or the groups exemplified as the substituent of the alkyl group are mentioned.

The heterocyclic groups represented by R ₁ and R ₂ include
For example, a pyridyl group (2,3 or 4-pyridyl, 5-carboxy-2-pyridyl, 3,5-dichloro-2-pyridyl, 4,6-dimethyl-2-pyridyl, 6-hydroxy-2-pyridyl, , 3,5,6-tetrafluoro-
4-pyridyl, 3-nitro-2-pyridyl, etc.), oxazolyl group (5-carboxy-2-benzoxazoline,
2-benzoxazoline, 2-oxazoline, etc.), thiazolyl group (5-sulfamoyl-2-benzthiazolyl, 2-benzothiazolyl, 2-thiazolyl, etc.), imidazolyl group (1-methyl-2-imidazolyl, 1-methyl-5-carboxy) -2-benzimidazolyl, etc.), furyl group (3-furyl, etc.), pyrrolyl group (3-pyrrolyl, etc.), thienyl group (2-thienyl, etc.), pyrazinyl group (2-pyrazinyl, etc.), pyrimidinyl group (2-pyrimidinyl, etc.) , 4-chloro-2-pyrimidinyl, etc.), pyridazinyl group (2-pyridazinyl, etc.), purinyl group (8-purinyl, etc.), isoxazolyl group (3-isoxazolyl, etc.), selenazolyl group (5-carboxy-2-selenazolyl, etc.) , A sulfolanyl group (such as 3-sulfolanyl), a piperidinyl group (1-methyl 3-piperidinyl and the like), pyrazolyl group (3-pyrazolyl etc.), tetrazolyl (1
-Methyl-5-tetrazolyl, etc.), and the heterocyclic group includes those having a substituent, and examples of the substituent include those exemplified above as the alkyl group and the substituent of the alkyl group.

The alkoxycarbonyl group represented by R ₂ includes, for example, methoxycarbonyl, ethoxycarbonyl, i-propoxycarbonyl, t-butoxycarbonyl, pentyloxycarbonyl, dodecyloxycarbonyl and the like. Examples of the aryloxycarbonyl group include a phenoxycarbonyl and a naphthyloxycarbonyl group. Examples of the carbamoyl group include aminocarbamoyl, methylcarbamoyl,
Ethylcarbamoyl, i-propylcarbamoyl, t-
Butylcarbamoyl, dodecylcarbamoyl, phenylcarbamoyl, 2-pyridylcarbamoyl, 4-pyridylcarbamoyl, benzylcarbamoyl, morpholinocarbamoyl, piperazinocarbamoyl and the like. Examples of the acylamino group include a methylcarbonylamino, an ethylcarbonylamino, an i-propylcarbonylamino, a t-butylcarbonylamino, a dodecylcarbonylamino, a phenylcarbonylamino, a naphthylcarbonylamino group and the like. Examples of the ureide group include methyl ureide, ethyl ureide, i-propyl ureide, t-butyl ureide, dodecyl ureide, phenyl ureide, 2-pyridyl ureide, and thiazolyl ureide group. Examples of the amino group include amino, methylamino, ethylamino, i-propylamino, t-butylamino, octylamino, dodecylamino, dimethylamino, anilino, naphthylamino, morpholino, and piperazino groups. Examples of the acyl group include methylcarbonyl, ethylcarbonyl, i-propylcarbonyl, t-butylcarbonyl,
Octylcarbonyl, dodecylcarbonyl, phenylcarbonyl, naphthylcarbonyl and the like. Examples of the alkoxy group include methoxy, ethoxy, i-propoxy, t-butoxy group, dodecyloxy group and the like. Examples of the aryloxy group include a phenoxy and naphthyloxy group. Examples of the sulfamoyl group include aminosulfamoyl, methylsulfamoyl, i-propylsulfamoyl, t-
Butylsulfamoyl group, dodecylsulfamoyl group,
Phenylsulfamoyl, 21-pyridylsulfamoyl, 4-pyridylsulfamoyl, morpholinosulfamoyl, piperazinosulfamoyl and the like. Examples of the sulfonamide group include methylsulfonamide, ethylsulfonamide, i-propylsulfonamide, t-butylsulfonamide, dodecylsulfonamide, phenylsulfonamide, and naphthylsulfonamide group.

Each of these groups includes those having a substituent, and examples of the substituent include the alkyl groups shown as R ₁ and R ₂ above and those exemplified as the substituent of the alkyl group.

Preferred as R ₁ is an aryl group having a substituent, particularly a phenyl group having a water-soluble group.

In the general formula (I), the 5- or 6-membered oxygen-containing heterocyclic group represented by B and the 6-membered nitrogen-containing heterocyclic group may be a furyl group (2- or 3-furyl, -Or 3-benzofuranyl, 1-isobenzofuranyl, etc.),
A pyranyl group (2-tetrahydropyranyl, 3,4,5 or 6-2H-pyranyl, 2 or 3-4H-pyranyl, 2
Or 3-chromanyl, 4-2H-chromenyl, 2-4H
-Chromenyl), a pyronyl group (2 or 3-4H-pyronyl, 2-chromonyl, 3-coumarinyl, 3-chromonyl, etc.), a pyridyl group (2,3 or 4-pyridyl, 2,3 or 4-quinolyl, 9- Acridyl, 3-thienopyridyl and the like; a pyrazinyl group (such as 2-pyrazyl); a pyrimidinyl group (such as 2,4 or 5-pyrimidinyl and 2-quinazolinyl); and a piperidinyl group (such as 3-piperidinyl). The heterocyclic group includes those having a substituent. Examples of the substituent include those exemplified as the alkyl group for R ₁ and R ₂ and the substituent for the alkyl group.
₂ of an amino group, an alkoxy group, those exemplified as the aryl group.

The methine groups represented by L _{1 to} L ₃ include those having a substituent. Examples of the substituent include an alkyl group (methyl, ethyl, i-propyl, t-butyl, 3-hydroxypropyl, benzyl, etc.). ), An aryl group (such as phenyl), a halogen atom (such as chlorine, bromine, iodine, and fluorine), an alkoxy group (such as methoxy and ethoxy), and an acyloxy group (such as acetyloxy and benzoyloxy).

Hereinafter, specific examples of the compound represented by formula (I) will be given, but the present invention is not limited to these.

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Next, the layer constitution in the light-sensitive material of the present invention will be described. The light-sensitive material of the present invention has at least one light-sensitive silver halide emulsion layer on one side of a support, and has a backing layer on the opposite side. The support is made of a transparent plastic base. Used. For example, cellulose triacetate (TAC), polyester (PET, PE
N or the like), polystyrene (SPS or the like) or the like can be used. For photosensitive materials for medical diagnosis, which is the main object of the present invention, 160-180
A PET (polyethylene terephthalate) base having a thickness of μm is preferred.

The support may be colored in a range where the transparency is maintained. By coloring the support in blue at a concentration of about 0.1 to 0.2, eye fatigue in observation of a transmission image by sharksten is reduced. It is preferable because it is possible.

The support is usually subjected to an undercoating treatment in order to provide adhesion between the support and the constituent layer coated on the support.

The constituent layers on the side having the photosensitive silver halide emulsion layer include a conductive layer (antistatic layer), an intermediate layer, a filter dye layer, a protective layer and the like in addition to the photosensitive silver halide emulsion layer. Is also good.

In the case of the present invention, it is preferable to have a protective layer, and it is preferable to adjust the matte degree, which is a constituent requirement of the present invention, by a matting agent added to the protective layer. The dry thickness of the protective layer is preferably 0.4 to 1.0 μm, more preferably 0.5 to 0.8 μm. Examples of the additive to be added to the protective layer include Research Disclosure (described below).
(Hereinafter referred to as RD) can be used.

The light-sensitive silver halide emulsion layer may be a single layer or a multi-layer, but one of the objects of the present invention is to provide a mammographic light-sensitive material having a multilayer structure in order to obtain a high contrast. Is preferably lower than the emulsion sensitivity of the lower layer. The contrast (γ) is 3.6 to
A range of 4.7 is preferred. In this case, the sensitivity of the lower emulsion is 0.1 to 0.4 in relative logarithm to the adjacent upper emulsion.
High sensitivity is preferable, and furthermore, 0.15 to 0.3
High sensitivity is preferred.

The thickness of the photosensitive silver halide emulsion layer when dried is preferably from 2 to 4.6 μm as a total of all the photosensitive silver halide emulsion layers, and the thickness ratio between the respective emulsion layers may be arbitrary. . As additives to be added to the silver halide emulsion layer, those described in RD below can be used.

The total thickness of the photosensitive silver halide emulsion layer when dried is preferably 5 μm or less, more preferably 3.5 μm or less.

The layer structure on the backing layer side includes an antihalation dye layer solid-dispersed from the side near the support,
It has an intermediate layer containing the above-mentioned polymer particles and an outermost layer substantially not containing the polymer particles, and further contains a conductive layer (antistatic layer), an intermediate layer, a dye layer and the like in addition to these layers. Is also good.

The antihalation dye layer contains the above-mentioned dye in a solid dispersion state, and as a binder, gelatin, polymer latex and those described in RD below can be used. 0.1 ~
1.0 g / m ² is preferable, and 0.2 to 0.5 g / m ² is more preferable.
m ² is preferred.

The dry thickness of the intermediate layer containing the polymer particles is preferably 0.5 to 3 μm, more preferably 1 to 2 μm.
μm is preferred.

The dry thickness of the outermost layer substantially free of polymer particles is preferably 0.5 to 3 μm, more preferably 0.7 to 1.5 μm. As additives to be added to these layers, those described in RD described later can be used.

The silver halide grains may have any shape, for example, cubic, octahedral, tetradecahedral, spherical,
It may have a shape such as a flat plate or a potato. Particularly preferred are tabular grains.

Tabular grains are crystallographically classified as twins. Twins are crystals having one or more twin planes in one grain. Classification of the twin morphology in silver halide grains is based on the report by Klein and Moiser, Photo
graphishe Korrespondenz "9
The details are described in Volume 9, page 99, and Volume 100, page 57.

The tabular silver halide grains used in the present invention have one or two or more twin planes parallel to each other in the grains, and these twin planes form the surface of the tabular grains. The plane exists substantially parallel to a plane having the largest area (also referred to as a main plane) among the planes. The most preferred form is when it has two parallel twin planes.

In the present invention, the aspect ratio refers to a ratio between the area-converted particle diameter and the particle thickness (that is, aspect ratio = equivalent circle diameter / thickness). Here, the area-converted particle size means the diameter of a circle having an area equal to the area when the particle is projected perpendicular to the main plane. On the other hand, the volume-converted grain size means the diameter of a sphere having the same volume as each silver halide grain. Grain thickness is the thickness of a grain in a direction perpendicular to the major plane and generally corresponds to the distance between the two major planes.

The average equivalent circle diameter of the tabular silver halide grains is preferably from 0.1 to 10.0 μm, more preferably from 0.2 to 10.0 μm.
5.0 μm is preferred, and 0.3 to 2.0 μm is particularly preferred. The average grain thickness is preferably 0.01 to 0.3 μm, more preferably 0.05 to 0.25 μm, and particularly preferably 0.07 to 0.2 μm.

The projected area and thickness of the particles for calculating the area-converted particle diameter and the volume-converted particle diameter can be obtained by the following methods.
That is, a sample was prepared by applying a latex ball having a known particle size as an internal standard on a support and silver halide particles such that the main plane was oriented parallel to the substrate, and shadowing was performed by carbon deposition from a certain angle. , A replica sample is prepared by a normal replica method. An electron micrograph of the replica sample is taken, and the projected area and thickness of each particle are determined using an image processing device or the like. In this case, the projected area of the particle can be calculated from the projected area of the internal standard, and the thickness of the particle can be calculated from the length of the internal standard and the shadow of the particle.

In the present invention, the average value of the aspect ratio, the area-converted particle size, the grain thickness, and the volume-converted particle size is determined by arbitrarily determining the number of silver halide grains contained in the silver halide emulsion by using the above-mentioned replica method. The value measured as above and obtained as an arithmetic average thereof is referred to.

The coefficient of variation of the silver halide grain in terms of volume is a value defined by the following equation using the value obtained from the above measurement. The coefficient of variation of the silver halide grains according to the present invention in terms of volume is preferably 0.2 or less.
It is more preferably at most 15 and particularly preferably at most 0.1.

Variation coefficient of volume-converted particle size = standard deviation of volume-converted particle size / average value of volume-converted particle size Similarly, from the above measurement, the coefficient of variation of the area-converted particle size of silver halide grains can be determined. Here, the variation coefficient of the area-converted particle diameter is a value defined by the following equation.

The coefficient of variation of the area-converted grain size of the silver halide grains according to the present invention is preferably 0.2 or less, more preferably 0.15 or less, and particularly preferably 0.1 or less.

Coefficient of variation of area-converted grain size = standard deviation of area-converted grain size / average value of area-converted grain size The silver halide emulsion used in the present invention is obtained by analyzing all of the silver halide grains contained in the silver halide emulsion. Preferably, 50% or more of the projected area is tabular grains having an average aspect ratio of 1.5 to 300 (hereinafter also simply referred to as aspect ratio), and 50% or more of the total projected area is an aspect ratio of 3 to 5
It is more preferred that the tabular grains have an aspect ratio of 0 to 25, and particularly preferred that they are tabular grains having an aspect ratio of 5 to 25.

It is preferable that 80% or more of the total projected area of the silver halide grains contained in the silver halide emulsion is the above-mentioned tabular grains.

The tabular silver halide grains according to the present invention include:
It has one or two or more twin planes parallel to each other in the grains, but preferably at least 50% of the tabular grains are tabular grains having two twin planes parallel to each other in the grains, More preferably, it is at least 80%. These twin planes can be observed with a transmission electron microscope.

The specific method is as follows. First, a silver halide emulsion is applied on a substrate so that the main plane of the contained tabular grains is oriented substantially parallel to the substrate to prepare a sample. This is continuously cut perpendicular to the substrate using a diamond cutter to obtain a continuous thin section having a thickness of about 0.1 μm. By observing this section with a transmission electron microscope, the existence and position of the twin plane can be confirmed.

The composition of the silver halide grains is preferably silver iodobromide, silver bromide, silver chlorobromide, or silver chloroiodobromide. In particular, it is preferably silver iodobromide having an average silver iodide content of 2 mol% or less, more preferably 1 mol% or less, particularly preferably 0.5 mol% or less. preferable. The composition of silver halide grains is determined by EPMA method, X
It can be examined using a composition analysis method such as a line diffraction method.

The average silver iodide content of the surface phase of the silver halide grains is preferably 3 mol% or less, and 0.1 to 2 mol%.
Mol% is more preferable, and 0.2 to 1 mol% is still more preferable. The average silver iodide content of the surface phase of the silver halide grains referred to herein is a value obtained by using the XPS method or the ISS method. For example, the surface silver iodide content by the XPS method can be obtained as follows.

That is, the sample was cooled to −155 ° C. or less in an ultra-high vacuum of 1.33 × 10 ⁻² Pa or less,
Irradiate MgKa as an X-ray at an X-ray source current of 40 mA,
The measurement is performed on 3d5 / 2, Br3d, and I3d3 / 2 electrons. The integrated intensity of the measured peak is corrected by a sensitivity factor, and the composition such as the silver iodide content of the silver halide surface phase is determined from these intensity ratios.

The silver halide emulsion used in the present invention is:
It is preferable that the silver iodide content between silver halide grains is more uniform. That is, the coefficient of variation of the silver iodide content is 30%.
Or less, more preferably 20% or less. However, the coefficient of variation here is
It is a value obtained by dividing the standard deviation of the silver iodide content by the average value of the silver iodide content and multiplying by 100, and can be used to arbitrarily measure 500 or more silver halide grains contained in the silver halide emulsion. Say the value given.

It is preferable to use a production method in which an aqueous solution containing a salt is appropriately extracted from the reaction solution using an ultrafiltration device. For example, the average intergranular distance in the growth process of silver halide grains is set to 0.
It is preferably controlled to 60 to 1.00 times, and 0.60 to 1.00.
More preferably, it is controlled to 0.80 times. Specifically, the value of the average interparticle distance is preferably controlled to 3.2 μm or less, more preferably to 2.8 μm or less, and particularly preferably to 0.90 to 2.0 μm.

As the preparation form of the silver halide emulsion, a method known in the art can be appropriately applied. For example, a so-called controlled double jet method or controlled triple jet method for controlling pAg of a reaction solution at the time of forming silver halide grains can be used.
A silver halide solvent can be used if necessary. Examples of useful silver halide solvents include ammonia, thioethers and thioureas. Regarding thioethers, U.S. Pat. Nos. 3,271,151, 3,790,387, and 3,574,626 can be referred to. The method for preparing silver halide grains is not particularly limited, and an ammonia method, a neutral method using no ammonia, an acidic method, and the like can be used.
From the viewpoint that fogging during silver halide grain formation can be suppressed, it is preferable to form grains in an environment where the pH (the logarithm of the reciprocal of the hydrogen ion concentration) is 5.5 or less, more preferably 4.5 or less. .

The silver halide emulsion contains a dispersion medium together with silver halide grains. The dispersion medium is a compound having a protective colloid property for silver halide grains, and is preferably present from the nucleation step to the end of grain growth. Preferred dispersion media include gelatin and protective colloid polymers.

As gelatin, usually, a molecular weight of 100,
About 000 alkali-treated gelatin or acid-treated gelatin,
Alternatively, low molecular gelatin or oxidized gelatin having a molecular weight of about 5,000 to 30,000 can be preferably used. In particular, at the time of nucleation, oxidized gelatin, low molecular weight gelatin, and oxidized low molecular weight gelatin can be suitably used.

Incidentally, in the silver halide emulsion of the present invention, the technique described in RD308119 can be used.

The silver halide grains can be subjected to chemical sensitization by a commonly used method. Chemical ripening, ie, the conditions of the process of chemical sensitization, such as pH, pAg, temperature,
There is no particular limitation on the time and the like, and the reaction can be performed under conditions generally performed in the art.

Chemical sensitization includes a sulfur sensitization method using a compound containing sulfur capable of reacting with silver ions or active gelatin, a selenium sensitization method using a selenium compound, a tellurium sensitization method using a tellurium compound, a reducing substance, , A noble metal sensitization method using a noble metal, and the like. These methods may be used alone or in combination. Among them, selenium sensitization, tellurium sensitization, reduction sensitization, and the like are preferably used, and selenium sensitization is particularly preferably used.

Examples of useful selenium sensitizers include colloidal selenium metal, isoselenocyanates (such as allyl isoselenocyanate), and selenoureas (N, N
Dimethylselenourea, N, N, N'-triethylselenourea, etc., selenoketones (selenoacetone, selenoacetophenone, etc.), selenoamides (selenoacetamide, N, N-dimethylselenobenzamide, etc.), selenocarboxylic acids and seleno Esters (such as 2-selenopropionic acid and methyl-3-selenobutyrate), selenophosphates (such as tri-p-triselenophosphate), and selenides (diethylselenide, diethyldiselenide, and triphenylphosphineselenide) Etc.). Particularly preferred selenium sensitizers are selenoureas, selenamides and selenoketones.

The amount of the selenium sensitizer used depends on the selenium compound used, silver halide grains, chemical ripening conditions and the like, but is generally from 10 ^-8 to 10 per mol of silver halide.
^{It is} preferable to use about ^-4 mol. Depending on the properties of the selenium compound to be used, the addition method may be a method in which the compound is dissolved in water or an organic solvent such as methanol, ethanol, or ethyl acetate alone or in a mixed solvent, or a method in which the compound is previously mixed with a gelatin solution and added. Or JP-A-4-14073.
No. 9, that is, a method of adding in the form of an emulsified dispersion of a mixed solution with an organic solvent-soluble polymer.

The silver halide grains may be spectrally sensitized with methine dyes or the like. Dyes used include cyanine dyes, merocyanine dyes, complex cyanine dyes, complex merocyanine dyes, holopolar cyanine dyes, hemicyanine dyes, styryl dyes, and hemioxonol dyes. Particularly useful dyes are those belonging to the cyanine dyes, merocyanine dyes and complex merocyanine dyes.

As these dyes, any of the nuclei generally used can be applied. That is, pyrroline, oxazoline,
Thiazoline, pyrrole, oxazole, thiazole, selenazole, imidazole, tetrazole, pyridine nucleus and the like, these nuclei are fused with an aliphatic hydrocarbon ring,
That is, indolenine, benzindolenin, indole,
Benzoxazole, naphthoxazole, benzothiazole, naphthothiazole, benzoselenazole, benzimidazole, quinoline nucleus and the like can be applied. These nuclei may have substituents on carbon atoms.

The merocyanine dye or the complex merocyanine dye includes pyrazoline- as a nucleus having a ketomethine structure.
5- to 6-membered heterocyclic nuclei such as 5-one, thiohydantoin, 2-thiooxazolidine-2,4-dione, thiazoline-2,4-dione, rhodanine and thiobarbituric acid nuclei can be applied.

The sensitizing dyes particularly useful in the present invention are trimethine cyanine dyes which give spectral sensitivity to green light, and specific examples thereof include oxalates described in JP-A-7-28184, pp. 2-12. It is a carbocyanine dye or a benzimidazolocarbocyanine dye.

These sensitizing dyes may be used alone or in combination, and the combination is often used particularly for supersensitization. The emulsion layer may contain a dye having no spectral sensitization or a substance which does not substantially absorb visible light and exhibits supersensitization, together with the sensitizing dye. For example, a substituted aminostilbene compound which is a nitrogen-containing heterocyclic nucleus (US Pat. No. 2,933,390)
No. 3,635,721) and an aromatic organic acid formaldehyde condensate (US Pat. No. 3,743,51).
No. 0), cadmium salts, azaindene compounds and the like. US Patent 3,615,613
Nos. 3,615,641 and 3,617,295
Nos. 3,635,721 and the like are particularly useful.

The sensitizing dye may be added during or during each step of nucleation, growth, desalting, and chemical sensitization, or after chemical sensitization.

The light-sensitive material is dried by adding an appropriate amount of a hardening agent in advance in the coating step of the light-sensitive material so as to be suitable for rapid processing, and adjusting the swelling ratio in the development-fixing-washing step. It is preferable to reduce the water content in the photosensitive material before the start.

The swelling ratio of the light-sensitive material of the present invention during the development processing is preferably 100 to 200%. The swelling ratio is obtained by calculating the difference between the film thickness after swelling in each processing solution and the film thickness before development processing, dividing the difference by the film thickness before processing and multiplying by 100.

Various photographic additives can be used in the light-sensitive material according to the present invention. Known additives include, for example, RD17643, page 23, section III to page 29, section XXI (197
December, 1981), pp. 18716, 648, upper right to p. 651, left (November 1979) and 308, 119, 996.
Compounds described in Sections III to 1009, Section XVII (December 1989) (chemical sensitizers, sensitizing dyes, desensitizing dyes, dyes, development accelerators, fog inhibitors / stabilizers, brighteners, hardeners) Filming agents, surfactants, antistatic agents, plasticizers, sliding agents, matting agents, binders, and supports).

Preferred developing agents of the developing solution for developing the light-sensitive material of the present invention include JP-A-4-15641 and JP-A-4-15641.
Dihydroxybenzenes (hydroquinone), para-aminophenols (p-aminophenol, N-methyl-p-aminophenol,
4-diaminophenol, etc.), 3-pyrazolidones (1
-Phenyl-3-pyrazolidone, 1-phenyl-4-methyl-4-hydroxymethyl-3-pyrazolidone, 5,
5-dimethyl-1-phenyl-3-pyrazolidone, etc.),
Ascorbic acids and the like are preferably used in combination.

Further, dihydroxybenzenes, para-aminophenols, 3-hydroxybenzenes,
Pyrazolidones and ascorbic acids have a total mole number of 0.1
It is preferably at least mol / liter.

The preservatives may include sulfites (potassium sulfite, sodium sulfite, etc.), reductones (piperidinohexose reductatone, etc.), and preferably 0.2 to 1 mol / l. And more preferably 0.3 to 0.6 mol / liter.
Also, addition of a large amount of ascorbic acids leads to processing stability. Sodium hydroxide,
PH adjusters such as potassium hydroxide, sodium carbonate, potassium carbonate, sodium tertiary phosphate and potassium tertiary phosphate are included. Further, buffers such as borate described in JP-A-61-28708 and saccharose, acetoxime, 5-sulfosalicylic acid, phosphate and carbonate described in JP-A-60-93439 may be used. The content of these chemicals is adjusted so that the pH of the developer is 8.5 to 11.5, preferably pH 9.5 to
Choose to be 10.5.

As a solubilizer, diethylene glycol, triethylene glycols and esters thereof can be contained, and as a sensitizer, a development accelerator such as a quaternary ammonium salt, a surfactant and the like can be contained.

The silver sludge inhibitor is disclosed in JP-A-56-1981.
No. 106244, silver stain inhibitor, JP-A-3-518
The sulfides and disulfide compounds described in JP-A No. 44, and the cysteine derivatives or triazine compounds described in JP-A-5-289255 are preferably used.

As organic inhibitors, azole organic antifoggants such as indazole, imidazole, benzimidazole, triazole, benzotriazole, tetrazole, thiadiazole, mercaptoazole (particularly 1-phenyl-5-mercapto) A tetrazole) compound. As inorganic inhibitors,
It can contain sodium bromide, potassium bromide, potassium iodide and the like. In addition, L. F. A. Mason, "Photographic Processing Chemistry", Focal Press (1966), pp. 226-229, U.S. Pat. Nos. 2,193,015 and 2,592,364,
Those described in JP-A-48-64933 may be used.

Examples of the chelating agent for masking calcium ions mixed in tap water used in the treatment liquid include chelating agents having a chelate stabilization constant with iron of 8 or more described in JP-A-1-193853 as an organic chelating agent. It is preferably used. Examples of the inorganic chelating agent include sodium hexametaphosphate, calcium hexametaphosphate, and polyphosphate.

A dialdehyde compound may be used as a developing hardener. In this case, glutaraldehyde is preferably used.

The amount of replenishment of the developing solution for developing the light-sensitive material of the present invention is 50 to 150 ml / m ² of the light-sensitive material.
Is preferable, and 65 to 130 ml is more preferable.

The fixing solution may contain a fixing agent generally used in the art. Examples of the fixing agent include thiosulfates such as ammonium thiosulfate and sodium thiosulfate, and ammonium thiosulfate is particularly preferable in view of the fixing speed. The concentration of the ammonium thiosulfate is preferably in the range of 0.1 to 5 mol / l, more preferably 0.8 to 5 mol / l.
３3 mol / liter.

The fixing solution has a pH of 3.8 or more, preferably 4.2 or more. In the present invention, the fixing solution may form an acidic film. In this case, an aluminum compound is preferably used as the hardener. For example, it is preferable to add in the form of aluminum sulfate, aluminum chloride, potash and the like.

The fixing solution may further contain a preservative such as sulfite or bisulfite, a pH buffer such as acetic acid or boric acid, a mineral acid (sulfuric acid, nitric acid) or an organic acid (citric acid, oxalic acid, etc.), if desired. PH adjusters such as various acids such as malic acid and hydrochloric acid, metal hydroxides (such as potassium hydroxide and sodium hydroxide), and chelating agents having the ability to soften hard water.

Examples of the fixing accelerator include, for example,
No. 35754, No. 58-122535, No. 58-12
No. 2536, thiourea derivatives, U.S. Pat.
Thioether described in US Pat. No. 6,459.

The amount of replenishment of the fixing solution for fixing the light-sensitive material of the present invention is 50 to 150 ml / m ² of the light-sensitive material.
Is preferable, and 65 to 130 ml is more preferable.

For development processing of the photosensitive material, a method using a solid processing agent is preferred. To solidify the photographic processing agent, a concentrated liquid or a fine or granular photographic processing agent and a water-soluble binder are kneaded and molded, or a water-soluble binder is sprayed on the surface of the temporarily formed photographic processing agent. Any means such as forming a coating layer can be adopted (see JP-A-4-29136 and JP-A-4-29136).
No. 85535, No. 4-85536, No. 4-85533
Nos. 4-85534 and 4-172341).

A preferred tablet production method is a method in which a powdery solid processing agent is granulated and then subjected to a tableting step to form the tablet. Simply mixing the solid processing agent components, the solubility and storage stability are improved over the solid processing agent formed by the tableting process,
As a result, there is an advantage that the photographic performance becomes stable.

Granulation methods for tablet formation include rolling granulation,
Known methods such as extrusion granulation, compression granulation, crushing granulation, stirring granulation, fluidized bed granulation, and spray drying granulation can be used. For tablet formation, the average particle size of the obtained granules is determined by mixing the granules and pressing / compressing them to make the components non-uniform,
100-800 in that so-called segregation hardly occurs.
μm, more preferably 2 μm.
It is 00 to 750 μm. Further, the particle size distribution is preferably such that 60% or more of the granulated product particles have a deviation of ± 100 to 150 μm.

Next, when the obtained granules are pressed and compressed, a known compressor such as a hydraulic press, a single-shot tableting machine, a rotary tableting machine, a briquetting machine and the like are used. Can be used. The solid processing agent obtained by pressurization and compression can take any shape, but productivity,
From the viewpoint of handleability and the problem of dust when used on the user side, a cylindrical type, so-called tablet, is preferred.

More preferably, at the time of granulation, the above-mentioned effect becomes more remarkable by separately granulating each component, for example, an alkali agent, a reducing agent, a preservative, and the like.

A method for producing a tablet processing agent is described in, for example,
Nos. 1-61837, 54-155038 and 52-
No. 88025, British Patent No. 1,213,808, etc. and can be produced by a general method. Granulating agents are described in, for example, JP-A-2-10942, JP-A-2-109043, JP-A-3-39735 and JP-A-3-39735. It can be produced by a general method described in JP-A-3-39739. Powder processing agents are described, for example, in JP-A-54-133332 and British Patent 725,89.
No. 2,729,862 and German Patent 3,733,333.
No. 861, etc., and can be produced by a general method.

The bulk density of the solid processing agent is preferably 1.0 to 2.5 g / cm ³ in the case of a tablet from the viewpoint of its solubility and the effect of the object of the present invention. 1.0 g / cm ³
Greater is 2.5% in terms of the strength of the resulting solid.
Less than g / cm ³ is more preferable in terms of solubility of the obtained solid. When the solid processing agent is granules or powder, the bulk density is preferably from 0.40 to 0.95 g / cm ³ .

The automatic developing machine used in the present invention is preferably a known roller-type automatic developing machine. When processing the light-sensitive material of the present invention, it is preferable that the processing is performed in a total processing time (dry to dry) of 10 to 45 seconds using an automatic developing machine, but the processing is performed in a range of 15 to 30 seconds. More preferred. Here, the time from the time when the tip of the photosensitive material to be processed is immersed in the developing tank liquid of the automatic developing machine to the time when it comes into contact with the fixing tank liquid in the next process is referred to as “development time”. "Fixing time" refers to the time until contact with the washing tank solution (stabilizing solution), "Washing time" refers to the time of immersion in the washing tank solution, and "Drying time" refers to the time in the drying zone of the automatic processor. , The developing time is 3 to 15 seconds (further 3 to 10 seconds), the developing temperature is 25 to 50 ° C. (further 30 to 40 ° C.), the fixing time is 2 to 12 seconds (further 2 to 10 seconds).
Sec), fixing temperature 20-50 ° C (further 30-40 ° C),
Water washing (stabilization) time 2 to 15 seconds (further 2 to 8 seconds), water washing (stabilization) temperature 0 to 50 ° C (further 15 to 40 ° C),
Drying time 3-12 seconds (further 3-8 seconds), drying temperature 35
To 100 ° C (more preferably 40 to 80 ° C).

The photosensitive material is developed, fixed and washed (or stabilized), dried with a squeeze roller, and then dried.

As the X-ray generator in the image forming method of the present invention, a commercially available X-ray generator can be used. Particularly, as an X-ray generator for mammography, an apparatus having a tube voltage of an X-ray generator tube of 40 kVp or less is commercially available. When the tube voltage of the X-ray generator exceeds 40 kVp, it is difficult to obtain a sufficient contrast.

As a dedicated device for mammography, X
Molybdenum (Mo) is used for the anode of the wire generating tube,
By adding a filter, continuous X-rays of 20 kVp or more that cause a decrease in contrast due to scattering are removed,
Devices that generate X-rays close to a single color including characteristic X-rays have become mainstream. Rhodium (R) is used to obtain contrast in high-density breasts and thick breasts with high X-ray absorption.
An apparatus in which an Rh filter is combined with an h) anode or a tungsten (W) anode is also known. The focal spot size of the anode tends to be miniaturized, and an apparatus having a diameter of 0.1 to 0.3 mm is generally used.

Preferred phosphors used in the X-ray fluorescent intensifying screen include the following. Tungstate phosphors (CaWO ₄ , MgWO ₄ , CaWO ₄ :
Pb etc.), 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, Tm, etc., terbium-activated rare earth phosphate-based phosphor (YPO ₄ : Tb, GdPO ₄ : T)
b, LaPO ₄ : Tb, etc.), terbium-activated rare earth oxyhalide phosphor (LaOBr: Tb, LaOB)
r: Tb. Tm, LaOCl: Tb, LaOCl: T
b. TmGdOBr: Tb, GdOCr: Tb, etc., thulium-activated rare earth oxyhalide-based phosphor (LaO
Br: Tm, LaOCl: Tm, etc.), barium sulfate-based phosphors (BaSO ₄ : Pb, BaSO ₄ : Eu ²⁺⁾ , (Ba.
Sr) SO ₄ : Eu ²⁺ etc.) divalent eurobium activated alkaline earth metal phosphate phosphor (Ba ₃ (PO ₄ ) ₂ : E
u ²⁺ , (Ba, Sr) ₃ , (PO ₄ ) ₂ : Eu _2, etc.), divalent eurobium-activated alkaline earth metal fluorohalide-based phosphor (BaFCl: Eu ²⁺ , BaFBr: Eu ²⁺⁾ ,
BaFCl: Eu ²⁺ . Tb, BaFBr: Eu ²⁺ . T
b, BaF ₂ . BaCl ₂ . XBaSO ₄ . KCl: Eu
²⁺ , (Ba.Mg) F ₂ . BaCl ₂ . KCl: Eu
²⁺ ), iodide-based phosphors (CSI: Na, CSI: T
1, NaI. KI: Tl, etc.), sulfide-based phosphor (Zn
S: Ag, (Zn. Cd) S: Ag, (Zn. Cd)
S: Cu, (Zn. Cd) S: Cu. Al), a hafnium phosphate-based phosphor (HfP ₂ O ₇ : Cu, etc.). However, the phosphor used in the present invention is not limited to these.

Of these, terbium-activated gadolinium oxysulfide (Gd ₂ O ₂ S: Tb) is particularly preferred as a phosphor.

The average particle diameter of each phosphor layer constituting each phosphor layer is represented by R, and the particle diameter distribution is represented by σ.
It is preferable that each layer satisfy the relationship of 0 <σ / R ≦ 0.5. Preferably, 0 <σ in each layer
/R≦0.3, more preferably 0 <σ / R ≦ 0.15 in each layer.
Here, the average particle size R indicates the number average, and the particle size distribution σ indicates the standard deviation.

The filling rate of the phosphor in the phosphor layer of the X-ray fluorescent intensifying screen is 68% or more, preferably 70% or more, more preferably 72% or more. As a method of increasing the filling rate, a method of using a thermoplastic elastomer as a binder and performing a compression treatment to reduce the porosity in the phosphor layer is known.

The thickness of the phosphor layer is not less than 135 μm, preferably from 150 to 250 μm.

It is preferable that the X-ray fluorescent intensifying screen is filled with a phosphor in a gradient particle size structure. In particular, it is preferable to coat large-sized phosphor particles on the surface protective layer side, and to coat small-sized phosphor particles on the support side.
2.0 μm, and those having a large particle diameter are preferably in the range of 10 to 30 μm.

The X-ray fluorescent intensifying screen used in the present invention has an X-ray absorption of 45% or more, preferably 50% or more, by increasing the filling rate of the phosphor particles. Incidentally, the X-ray absorption amount is obtained as follows. That is, X-rays generated from a tungsten target operated at 80 kVp from an X-ray generator equivalent to 2.2 mm of aluminum and passed through a 3 mm-thick aluminum plate having a purity of 99% or more are supplied by three-phase power supply. The X-ray fluorescence intensifying screen was fixed at a position 200 cm from the tungsten anode of the target tube, and then measured with an ionizing dosimeter at a position 50 cm after the phosphor layer of the X-ray fluorescence intensifying screen. And
X-ray absorption was determined. As a reference, the X-ray dose at the above measurement position measured without passing through the fluorescent intensifying screen was used.

Preferred binders used in the X-ray fluorescent intensifying screen include thermoplastic elastomers. Specifically, polystyrene, polyolefin, polyurethane,
At least one thermoplastic elastomer selected from the group consisting of polyester, polyamide, polybutadiene, ethylene vinyl acetate, polyvinyl chloride, natural rubber, fluorine rubber, polyisoprene, chlorinated polyethylene, styrene-butadiene rubber and silicone rubber. .

[0167]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these embodiments.

Example 1 All the emulsions shown below were prepared in a reaction vessel having a volume of 32 liters. In addition, Asahi Kasei SIP-1013 is used as the ultrafiltration unit, and DAID is used as the circulating pump.
O Rotary Pump was used. The volume of the emulsion circulation portion of the ultrafiltration step was 1.2 liters, and the emulsion was circulated at a constant flow rate of 15 liters / minute. Therefore, the residence time of the reactant solution was 4.8 seconds, and the volume of the emulsion circulation portion in the ultrafiltration step was 3.8% of the volume of the reaction vessel.

The control of the distance between the particles during the particle growth process was performed by appropriately controlling the permeation flux in the ultrafiltration step. Specifically, the flow control valve 1 shown in FIG.
9 so as to maintain the average distance between the particles at the start of the particle growth step 1 over the entire area of the particle growth step 1 and the particle growth step 2 so that the reaction solution in the reaction vessel is ultrafiltered. And concentrated. (Em-1: Preparation of Lower Layer Emulsion) [Nucleation Step] The following gelatin solution B-10 in a reaction vessel
1 was maintained at 30 ° C., and the pH was adjusted to 1.96 with 1N sulfuric acid while stirring at a stirring rotation speed of 450 rpm using the mixing and stirring apparatus of FIG. Thereafter, the S-101 solution and the X-101 solution were added at a flow rate of 5.0 ml / sec by using the double jet method to form nuclei. (B-101) Low molecular weight gelatin (average molecular weight: 20,000) 32.4 g Potassium bromide 9.92 g Water 12938.0 ml (S-101) Silver nitrate 50.43 g Water 225.9 ml (X-101) Potassium bromide 35. 33 g water 224.7 ml [Aging step] After the addition was completed, the following G-101 solution was added, and the temperature was raised to 60 ° C. over 30 minutes. After heating, 60
The stirring was maintained for 20 minutes while maintaining the temperature. Subsequently, the pH was adjusted to 9.5 by adding a 28% aqueous ammonia solution, and the mixture was maintained for 7 minutes. A 1N aqueous nitric acid solution was added thereto to adjust the pH to 5.
Adjusted to 8. During this time, the silver potential of the solution (measured with a silver ion selective electrode using a saturated silver-silver chloride electrode as a reference electrode) was 1N.
Was controlled to 14 mV by using a potassium bromide solution. (G-101) Alkali-treated inert gelatin (average molecular weight 100,000) 139.1 g 10% methanol solution of surfactant (AO-1) 4.64 ml water 3266.0 ml AO-1: HO (CH ₂ CH ₂ O) ) _M [CH (CH ₃ ) CH
₂ O] _19.8 (CH ₂ CH ₂ O) _n H (m + n = 9.77) [Grain growth step 1] After ripening, the flow rates of the S-102 solution and the X-102 solution are successively determined by the double jet method. While accelerating (The ratio of the addition flow rate at the end to the start is about 12 times) 3
Added in 8 minutes. After completion of the addition, add G-102 solution,
After adjusting the stirring rotation speed to 550 rpm, S
The -103 solution and the X-103 solution were added for 40 minutes while accelerating the flow rates (the ratio of the addition flow rates at the end and at the start was about twice). During this time, the silver potential of the solution was controlled at 14 mV using a 1N potassium bromide solution. (S-102) silver nitrate 639.8 g water 2866.2 ml (X-102) potassium bromide 448.3 g water 2850.7 ml (G-102) alkali-treated inert gelatin (average molecular weight 100,000) 203.4 g AO-1 10% methanol solution of 6.20 ml water 1867.0 ml (S-103) silver nitrate 989.8 g water 1437.2 ml (X-103) potassium bromide 679.6 g potassium iodide 9.5 g water 1412.0 ml [particle growth step 2] After completion of the addition, the temperature of the solution in the reaction vessel was lowered to 40 ° C. over 20 minutes. afterwards,
After adjusting the silver potential in the reaction vessel to −18 mV using a 3.5 N aqueous potassium bromide solution, the S-104 solution and X-1
Solution 04 was added for 7 minutes while accelerating the flow rate (the ratio of the addition flow rate at the end to the start was 1.2 times). (S-104) Silver nitrate 672.0 g Water 975.8 ml (X-104) Potassium bromide 470.8 g Water 959.4 ml Average over the entire area of the grain growth step 1 and the grain growth step 2 at the start of the grain growth step 1 To keep the distance between particles,
The reaction solution in the reaction vessel was circulated to an ultrafiltration device to perform concentration.

After completion of the growth, desalting and washing were carried out according to a conventional method, gelatin was added to the mixture, and the mixture was dispersed well. The pH was adjusted to 5.8 and the pAg was adjusted to 8.1 at 40 ° C. The resulting emulsion had an average grain thickness of 0.18 μm and an average grain diameter of 1.1.
The particles were hexagonal tabular grains having a size of 3 μm and an average aspect ratio of 6.3. This emulsion was designated as Em-1. (Em-2: Preparation of Upper Layer Emulsion)
Em-2 was prepared using the same equipment and method as 1. [Nucleation step] The following gelatin solution B-20 in a reaction vessel
1 was maintained at 30 ° C., and the pH was adjusted to 1.96 with 1N sulfuric acid while stirring at a stirring rotation speed of 450 rpm using the mixing and stirring apparatus of FIG. Then, the S-201 solution and the X-201 solution were added at a flow rate of 5.0 ml / sec by using the double jet method to form nuclei. (B-201) Low molecular weight gelatin (average molecular weight: 20,000) 32.4 g Potassium bromide 9.92 g Water 12938.0 ml (S-201) Silver nitrate 50.43 g Water 225.9 ml (X-201) Potassium bromide 35. 33 g water 224.7 ml [Maturation step] After the completion of the above addition, the following G-201 solution was added, and the temperature was raised to 60 ° C over 30 minutes. After heating, 60
The stirring was maintained for 20 minutes while maintaining the temperature. Subsequently, the pH was adjusted to 9.5 by adding a 28% aqueous ammonia solution, and the mixture was maintained for 7 minutes. A 1N aqueous nitric acid solution was added thereto to adjust the pH to 5.
Adjusted to 8. During this time, the silver potential of the solution (measured with a silver ion selective electrode using a saturated silver-silver chloride electrode as a reference electrode) was 1N.
Was controlled to 14 mV by using a potassium bromide solution. (G-201) Alkali-treated inert gelatin (average molecular weight: 100,000) 139.1 g 10% methanol solution of AO-1 4.64 ml water 3266.0 ml [Particle growing step 1] After ripening, the double jet method was performed. While increasing the flow rates of the S-202 solution and the X-202 solution by using (the ratio of the addition flow rate at the end to the addition at the start is about 12 times) 3.
Added in 8 minutes. After the addition is completed, add G-202 solution,
After adjusting the stirring rotation speed to 550 rpm, S
The -203 liquid and the X-203 liquid were added for 26 minutes while accelerating the flow rates (the ratio of the addition flow rate at the end to the start was about 1.4 times). During this time, the silver potential of the solution was controlled at 19 mV using a 1N potassium bromide solution. (S-202) Silver nitrate 639.8 g Water 2866.2 ml (X-202) Potassium bromide 448.3 g Water 2850.7 ml (G-202) Alkali-treated inert gelatin (average molecular weight 100,000) 203.4 g AO-1 6.20 ml of a 10% methanol solution of water 1867.0 ml of water (S-203) 389.8 g of silver nitrate 566 ml of water (X-203) 267.6 g of potassium bromide 5.6 g of potassium iodide 566 ml of water [particle growth step 2] After completion, the temperature of the solution in the reaction vessel was lowered to 40 ° C. in 20 minutes. afterwards,
After adjusting the silver potential in the reaction vessel to -18 mV using a 3.5 N aqueous potassium bromide solution, the S-204 solution and X-2
Solution 04 was added for 4.5 minutes while accelerating the flow rate (the ratio of the addition flow rate at the end to the start was 1.1 times). (S-204) Silver nitrate 308 g Water 447 ml (X-204) Potassium bromide 215.8 g Water 439.7 ml The average distance between the particles at the start of the particle growth step 1 over the entire area of the particle growth step 1 and the particle growth step 2 To be kept
The reaction solution in the reaction vessel was circulated to an ultrafiltration device to perform concentration.

After completion of the growth, desalting and washing were carried out according to a conventional method, gelatin was added and the mixture was dispersed well, and the pH was adjusted to 5.8 and the pAg was adjusted to 8.1 at 40 ° C. The resulting emulsion had an average grain thickness of 0.16 μm and an average grain diameter of 0.9
It was a hexagonal tabular grain having a size of 2 μm and an average aspect ratio of 5.8. This emulsion was designated as Em-2. (Chemical sensitization and spectral sensitization) Next, the above emulsions Em-1, Em
-2 was heated to 60 ° C., and spectral sensitizing dyes SD-1, SD-
A predetermined amount of 2 was added as a dispersion in the form of solid fine particles.
Minutes later, a mixed aqueous solution of adenine, ammonium thiocyanate, chloroauric acid and sodium thiosulfate and a sensitizer Se
-1 was added, and after 30 minutes, silver iodide fine particles were added, followed by ripening for a total of 2 hours. At the end of aging, a predetermined amount of stabilizer ST-1 was added.

The amount added per mol of silver halide is shown below. SD-1 270 mg SD-2 100 mg Adenine 10 mg Potassium thiocyanate 90 mg Chloroauric acid 20 mg Sodium thiosulfate 2.0 mg Se-1 0.2 mg Silver iodide fine particles 0.3 mmol ST-1 500 mg Gelatin 40 g SD-1: 5 5-dichloro-9-ethyl-3,3'-
Di- (sulfopropyl) oxacarbocyanine sodium salt anhydride SD-2: 5,5-di- (trifluoromethyl) -1-methyl-1'-ethyl-3,3'-di- (sulfopropyl) Benzimidazolocarbocyanine sodium salt anhydride Se-1: triphenylphosphine selenide ST-1: 4-hydroxy-6-methyl-1,3,3
a, 7-Tetrazaindene A solid particulate dispersion of the above-mentioned spectral sensitizing dye was prepared by a known method. That is, the predetermined amount of the spectral sensitizing dye is
High-speed stirrer (dissolver) in addition to water controlled at 7 ° C
At 3,500 rpm for 30 to 120 minutes.

A dispersion of the selenium sensitizer was prepared as follows. That is, 120 g of Se-1 was added to 30 kg of ethyl acetate at 50 ° C., and completely dissolved by stirring. On the other hand, 3.8 kg of photographic gelatin was dissolved in 38 kg of pure water, and to this was added 93 g of a 25% aqueous solution of sodium dodecylbenzenesulfonate. Next, these two liquids were mixed, and a high-speed stirring type disperser having a dissolver having a diameter of 10 cm was used.
Per second for 30 minutes. Thereafter, ethyl acetate was removed while rapidly stirring under reduced pressure until the residual concentration of ethyl acetate became 0.3% or less. Thereafter, this dispersion was diluted with pure water to finish up to 80 kg. A part of the dispersion thus obtained was fractionated and used. (Preparation of Emulsion Layer Coating Solution) The following various additives were added to each emulsion obtained above per mole of silver halide.

1,1-Dimethylol-1-bromo-1-nitromethane 7 mg t-butyl-catechol 130 mg polyvinylpyrrolidone (molecular weight 10,000) 1.0 g sodium polystyrenesulfonate 2.0 g trimethylolpropane 7.0 g nitrophenyl- Triphenyl-phosphonium chloride 20 mg Sodium 1,3-dihydroxybenzene-4-sulfonate 400 mg 2-Sodium 2-mercaptobenzimidazole-5-sulfonate 10 mg C ₄ H ₉ OCH ₂ CH (OH) CH ₂ N (CH ₂ COOH) ₂ 650 mg (Preparation of a coating solution for the protective layer on the emulsion layer side) (per 1 m ² ) Gelatin 0.9 g Polymer particles (particles shown in Table 1) Hardening agent H-1 Swelling ratio 150 % To be adjusted Object S-1 7 mg compound S-2 40 mg compound S-3 5 mg backing layer (Preparation of antihalation dye layer solution) (1 m ² per) Solid particle dispersion dyes (Compound I-11) 150 mg Gelatin 0.6g dodecylbenzenesulfonic Sodium sulfonate 2 mg Compound S-4 5 mg (Preparation of coating solution for intermediate layer) (Per 1 m ² ) Gelatin Amount shown in Table 1 Polymer particles (particles shown in Table 1) Adjusted to an amount that gives matte degree in Table 1 Solid fine particle dispersion Body dye (Exemplified Compound I-11) * Amount shown in Table 1 (Preparation of coating solution for protective layer) (per 1 m ² ) Gelatin 0.9 g Polymer particles (particles shown in Table 1) Adjustment Compound S-1 7mg Compound S-2 50mg Compound S-3 6mg Hardener H-1 Adjust the addition amount so that the swelling ratio becomes 150% * Preparation of fine particle dispersion dye: Water and surfactant Alkanol XC (manufactured by DuPont) are put in a ball mill container, dye (Exemplary Compound I-11) is added, zirconium oxide beads are put, and the container is sealed. And dispersed in a ball mill for 4 days. H-1: (CH ₂ ＣＨCHSO ₂ CH ₂ CONHCH ₂ —) ₂ S-1: Dihexyl sulfosuccinate sodium salt S-2: C ₁₁ H ₂₃ CON [(CH ₂ CH ₂ O) _m H] (C
H ₂ CH ₂ O) _n H where m + n = 10 S-3 : C 8 F 17 SO 2 N (C 3 H 7) (CH 2 CH 2 O) 15
H

[0175]

Embedded image

(Coating of light-sensitive material) By using these coating solutions, a silver amount of 1.5 g / m 2 was coated on one surface of the support.
² , 1.5 g / m ^{2 of} emulsion lower layer, emulsion protective layer gelatin amount of 0.1 g / m ² .
Glycidyl methacrylate using two slide hopper type coaters so that the amount of the antihalation dye layer, the intermediate layer and the protective layer on the other surface was 9 g / m ^2, and the amount of gelatin was as shown in Table 1. / Methyl acrylate /
A 175 μm-thick blue-colored PET coated and dried with a copolymer dispersion obtained by diluting a butyl methacrylate (50/10/40 mass ratio) copolymer so as to have a concentration of 10%, and drying it. Coating was performed simultaneously on both sides of the support at a speed of 120 m / min, and drying was performed for 2 minutes and 20 seconds to prepare a photosensitive material sample. <Preparation of solid developer> [Granulated product (A)] 1050 g of sodium metabisulfite,
450 g of 1-phenyl-3-pyrazolidone, 7200 g of sodium erysorbate monohydrate, 810 g of binder D-sorbit, 7 g of N-acetyl-DL-penicillamine,
300 g of the compound of A-7 was mixed at room temperature for about 3 minutes in a commercially available stirring granulator, and granulated by adding 150 ml of water over 1 minute. 5
After drying at 0 ° C. for 2 hours, the water content of the granulated material is almost completely removed. [Granulated product (B)] An average of 1500 g of potassium carbonate and 6.0 g of potassium iodide were each added in a commercially available bantam mill.
Grind to 0 μm. These fine powders and DTPA-
Na 170 g, sodium sulfite 425 g, 5-mercapto- (1H) -tetrazolylacetic acid sodium salt 8.3
g, 1- (3-sulfophenyl) -5-mercaptotetrazole sodium salt, binder mannitol 15
00 g and D-Sorbit 600 g were added and mixed at room temperature for about 3 minutes in a commercially available stirring granulator.
After granulation by adding over a period of minutes, the granulated material is dried at 40 ° C. for 2 hours in a fluidized drier to remove almost completely the water content of the granulated material. DTPA-Na: diethylenetriaminepentaacetic acid / pentasodium salt Sodium 1-octanesulfonate was added to the granulated product (A) thus obtained in an amount of 1.0% of the total mass, and methyl-β-
Cyclodextrin at 3% of total mass, 25 ° C., 40% R
H, and mixed in a room conditioned to not more than H. Further, in the granulated product (B), sodium 1-octanesulfonate was 1.2% of the total mass, methyl-β-cyclodextrin was 3% of the total mass, Addition and mixing in a room conditioned at 25 ° C and 40% RH or less, Tough Press Collect 1527H manufactured by Kikusui Seisakusho
U was subjected to compression tableting using a modified tableting machine to produce each of the developed tablets (A) and (B). The filling amount per tablet was (A) 8.45 g and (B) 12.4 g. Sixty tablets (A) and fifty (B) (volume having a capacity of 5.0 liters after dissolution) were sealed and packaged with a packaging material having the following layer structure for moisture prevention.

The packaging material is biaxially stretched nylon (ONY)
15 μm thickness / aluminum oxide deposited PET 12 μm thickness /
A bag made of a laminate material consisting of biaxially oriented polypropylene (OPP) 25 μm thick / low-density polyethylene (LLDP) 40 μm thick, and the effective surface area on the side (inside) of the packaging material in contact with the tablets was 1300 cm ² . . <Preparation of solid fixing agent> [Granulated product (C)] In a commercially available bantam mill, 14580 g of ammonium thiosulfate / sodium thiosulfate (90/10 mass ratio) is pulverized to an average of 10 µm. The compound (HOCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH _{2) is} added to the fine powder.
OH) 1000 g, sodium metabisulfite 920 g,
After adding 50 g of 5-mercapto-1H-tetrazole and 900 g of binder pine flow, mixing at room temperature for about 3 minutes in a commercially available stirring granulator, and granulating by adding 150 ml of water over 1 minute. The granules are dried at 40 ° C. in a fluidized bed drier to remove water almost completely. [Granulated material (D)] 250 g of boric acid, aluminum sulfate · 8
Water salt 1500 g, succinic acid 1150 g, tartaric acid 250 g,
208 g of mannitol and 100 g of D-sorbit were mixed at room temperature for about 3 minutes in a commercially available stirring granulator, and 150 ml was mixed.
Of water is added over 1 minute to granulate, and the granulated material is dried at 40 ° C. in a fluidized bed drier to remove water almost completely.

The granulated product (C) thus obtained, 1400 g of sodium acetate and sodium 1-hexanesulfonate in a room conditioned at 2.5% of the total mass and 25 ° C./40% RH or less. 1400 g of sodium acetate was added to the granulated product (D), and sodium 1-hexanesulfonate was further added to 3.0% of the total mass at 25 ° C./40%.
The mixture was added and mixed in a room humidified to RH or lower, and compressed and compressed using a tableting machine (described above) in which Tough Press Collect 1527HU was modified to produce fixing tablets (C) and (D). The filling amount per tablet is (C) 10.5 g, (D)
8.95 g. Using the packaging materials used for developing tablets (A) and (B) for moisture proof, 92 (C) and 28 (D) (the volume after dissolution becomes 5.0 liters) were used for moisture proofing. The tablets were sealed and packaged. <Formulation of development starter (addition amount per liter of developer)> N-acetyl-DL-penicillamine 0.11 g diethylene glycol 48.5 g 5-mercapto- (1H) -sodium tetrazolyl acetate 0.12 g 90% acetic acid 11.5 g bromide 8.0 g of potassium Finished to 67 ml with pure water (Developer) TCX-701 (manufactured by Konica Corporation) was used as an automatic developing machine. At the start, 7.8 liters of the developing solution in which the developing tablet was dissolved was added to the developing solution in the developing tank, and a starter was added to fill the developing tank as a starting solution to start processing. The starter was added in an amount of 67 ml / liter of the developing solution, and an amount corresponding to the developing tank capacity of 7.8 liter was added. Similarly, 5.6 liters of the prepared fixing solution was placed in a fixing processing tank of TCX-701 to be used as a starting solution.

In each of the developing and fixing steps, the one in which each packaging bag was opened by hand was set at the inlet of each solid agent.
Drop tablets into the built-in chemical mixer and add hot water (2
5-30 ° C.) and dissolve with stirring for 25 minutes.
Make up to 5.0 liters per minute. This was used as a developing and fixing replenisher.

The pH when the developer was dissolved was 10.15,
The pH when the starter was added was 9.90. The dissolution pH of the fixing solution was 4.25.

The built-in chemical mixer is divided into a liquid preparation tank and a spare tank tank. The capacity of the liquid preparation tank is 5.0 liters and the capacity of the spare tank is 5.0 liters. A spare tank is provided to supply the replenisher so that the replenisher does not enter the non-replenished state during the stirring and dissolving time (about 25 minutes) even if the replenisher produced runs out.

Development temperature 34 ° C. (replenishment rate is 100 ml / m
² ), fixing temperature 34 ° C. (replenishment amount is 100 ml / m ² ), water washing temperature 18 ° C. (5 l / min), drying temperature 55 ° C.
Was evaluated with a processing time of 45 seconds. (Evaluation of Performance of Photosensitive Material Sample) Using the obtained sample, the emulsion surface was brought into close contact with the phosphor layer surface of an X-ray fluorescent intensifying screen M-100 for mammography (manufactured by Konica) in a cassette. X-ray irradiation was performed after standing for 10 minutes in order to keep the adhesion high and constant. X-ray generator manufactured by Toshiba: ROTA
Using NODE, tube voltage 27kVp, tube current 100mA
(Focal size 0.4mm) from a distance of 60cm to 0.5
Irradiated for seconds. At this time, an acrylic plate having a thickness of 2 cm was placed at a position 20 cm from the anode, and the MT was brought into close contact with the cassette.
An X-ray square wave chart for F measurement was photographed.

The samples after photographing were subjected to the above-described developing treatment, and the MT method was performed by a contrast method from the obtained rectangular wave images of the samples.
F was measured. << Sharpness >> As for the evaluation of the sharpness, a spatial frequency of 5 (lp /
mm) and the relative value when the value of Sample 1 was set to 100. << Kutzuki Resistance >> The same sample conditioned for 12 hours under the air-conditioning conditions of 23 ° C. and 80% RH is overlaid and 1960 Pa
The film was left to stand for 3 days while a load was applied, and the degree of tightness between the films was evaluated in four stages of A to D as follows. B and above are considered as practicable levels.

A: No dustiness B: Less than 5% area C: Less than 5% to less than 15% D: More than 15% area. << Transportability >> Using an auto feeder KDA-500 (manufactured by Konica Corporation), 10 sets of 100 pieces each having four cut sizes are transported with the backing layer side up (that is, the sucker transport is performed on the backing layer side) and transported. The number of occurrences of defects was measured. Each time the sample was changed, the suction cup was cleaned with gauze moistened with alcohol. Samples are 23 ° C, 20% RH and 23 ° C
-Humidity was controlled at 80% RH for 2 hours, and transportability was evaluated under the same conditions.

Tables 1 and 2 show the results.

[0186]

[Table 1]

[0187]

[Table 2]

The sample of the present invention is superior to the comparative sample in all of sharpness, anti-stickiness, and transportability.

[0189]

According to the present invention, it is possible to provide a silver halide photographic light-sensitive material for medical X-ray photography, particularly for mammography, and an image forming method, which are excellent in sharpness, anti-stickiness and transportability. did it.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a silver halide emulsion manufacturing apparatus applicable to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reaction container 2 Stirring mechanism 3 Dispersion medium 4 Silver addition line 5 Halide addition line 6 Dispersion medium addition line 7 Addition line 8 Liquid take-out line 9 Liquid return line 10 Permeate discharge line 11 Permeate return line 12 Ultrafiltration unit 13 Circulation Pump 14 Flow meter 15, 16, 17 Pressure gauge 18 Pressure adjusting valve 19 Flow adjusting valve 20 Silver addition valve 21 Halide addition valve 22 Liquid extraction valve 23, 24, 25 Valve 26 Ultrafiltration permeate 27 Permeate receiver 28 Scale 29,30 Silver halide fine grain emulsion addition line 31,32 Fine grain addition valve

Claims (8)

[Claims] 1. A silver halide photographic material having at least one light-sensitive silver halide emulsion layer on one side of a support and a backing layer on the other side of the support. Matte degree of the side having the emulsion layer is 133
The matting degree on the side having the backing layer is 13300 to 39900 Pa, and the backing layer is a solid-dispersed antihalation dye layer from the side close to the support, and has an average particle size of 2 to 10 μm. A silver halide photographic light-sensitive material comprising an intermediate layer containing polymer particles having a standard deviation of 10% or less and an outermost layer containing substantially no polymer particles. 2. A silver halide photographic material having at least one light-sensitive silver halide emulsion layer on one side of a support and a backing layer on the other side of the support. Matte degree of the side having the emulsion layer is 133
5300 Pa, the matting degree on the side having the backing layer is 13300 to 39900 Pa, and the backing layer is an antihalation dye layer solid-dispersed from the side close to the support, having an average particle size of 2 to 10 μm and 5 ~ 15
A silver halide photographic light-sensitive material comprising an intermediate layer containing polymer particles containing mol% of an acidic monomer and an outermost layer containing substantially no polymer particles. 3. The silver halide photographic material according to claim 1, wherein the polymer particles are spherical polymer particles. 4. The silver halide photographic material according to claim 2, wherein the polymer particles have a relative standard deviation of 10% or less. 5. The surface of the silver halide photographic material according to claim 1, which has a phosphor layer of an X-ray fluorescent intensifying screen, in close contact with the surface of the silver halide photographic material having the photosensitive silver halide emulsion layer. An X-ray image is formed by irradiating the subject with X-rays transmitted through the subject, and thereafter developing, fixing, washing and drying with an automatic developing machine. 6. The image forming method according to claim 5, wherein the X-ray has a tube voltage of 40 kVp or less. 7. The silver halide photographic material according to claim 1, wherein the material is for X-ray mammography. 8. The image forming method according to claim 5, wherein the method is for X-ray mammography.