JPH02110538A - Combination body of photosensitive element for radiography - Google Patents

Abstract

PURPOSE: To decrease crossovers by constituting a combined body in such a manner that the radiations released by front and rear screens have the wavelengths different from each other and that respective silver halide layers are nonphotosensitive to the radiations released by the screens on the opposite side. CONSTITUTION: This combined body consists of a pair of the fluorescent screens 21, 20 for radiography and the double coated silver halide elements 10 for radiography. The respective screens 21, 20 are arranged adjacently to the respective silver halide layers 15, 14 and release the radiations for sensitizing the adjacent silver halide layers 15, 14 imagewise when subjected to imagewise exposure by X-rays. One of the fluorescent screens 21, 20 releases the first radiation in the first wavelength region of electromagnetic spectra and the other of the fluorescent screens 21, 20 releases the second radiation in the second wavelength region of the electromagnet spectra. In addition, the respective silver halide layers 15, 14 are so formed as to be nonphotosensitive to the radiations released by the screens 20, 21 on the opposite side. As a result, the excellent image quality is obtd. and the crossovers are decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a combination of fluorophores for use in synographies, particularly for use in industrial or mucinography. Combination body P of fluorescent screen illusion and double-sided coated silver halide radiography thick layer
Regarding L.

Perspectives of the Invention In radiography and medical radiography, a photosensitive element having silver halide emulsion layers coated on both sides of a transparent support (double-sided coated) is also referred to as a 10-gen halide emulsion. ) is used. In order to reduce the amount of X-ray radiation required to obtain the desired image, the double-sided coated silver lodenide element 1'':J,-ff is used in combination with a fluorescent screen. The fluorescent screens used in combination with each silver chloride emulsion layer of a double-coated element are generally the same. It is sensitized to a portion of the electromagnetic spectrum that corresponds to the wavelength of light emitted by the fluorescing material used in the process, and therefore provides significant amplification.

The image quality obtained by combining the screen pair with a double-sided coated silver element during X-ray processing; by exposing and developing the double-sided coated silver element is due to cross-over exposure. (qrossover exposure
) is negatively influenced by In a double-sided silver oxide device, the light emitted by the fluorescent screen passes through the adjacent 10-layer emulsion layer, and the light spreads across the support. , and when the silver halide emulsion layer on the opposite side of the support is exposed imagewise, cross-over exposure occurs which causes a reduction in image sharpness.

Element cost reduction or processing (procθθsing)
Even when using the entire photosensitive element with less silver coverage to increase speed, it causes poor definition in the crossover exposure source. In fact, the reduction in emulsion turbidity increases the total amount of light available for crossover and therefore image clarity.

Dyes and pigments can be fully used in radiographic elements to reduce cross-over exposure. The absorption band of the dye or pigment lies in the region of the electromagnetic spectrum that corresponds to the wavelength of the light emitted by the fluorescent screen. Since the dye or pigment absorbs to some extent the source emitted by the fluorescent screen, the light from the opposite screen is absorbed by this anti-crossover dye or pigment.
The degree to which the silver halide emulsion layer is imaged by the opposing screen is reduced. These dyes or pigments disappear during photographic development, processing, and washing processing of the exposed material; for example, they are washed away during processing of radiographic elements or are preferably washed out.

The dye may be incorporated into any layer of the photosensitive element: in an emulsion layer, in an interlayer between the emulsion and the base, or in a subbing layer. In order to avoid the risk of desensitization phenomena, it is preferred to incorporate the entire dye in a layer separate from the emulsion-containing layer.

Since 1978, iNesota Mining and Manufacturing Company has been a 3M)
A radiographic element named M-type XTJDX X-ray film is sold for use in combination with 3M) REMAXTM intensifying screens. Such radiographic elements consist of a transparent polyester paste coated on both sides with a silver halide emulsion (tfJ) sensitized to the light emitted by the screen. Between the emulsion and the base there is a layer of gelatin containing a water-soluble acid dye, the dye being decolorizable during processing, and a screen vc
: It absorbs at the distribution of the TJL magnetic spectrum and the spectral sensitivity of the emulsion corresponding to the wavelength of the emitted light. This dye is fixed in the layer by a basic mordant VC consisting of polyvinylpyricine.

The implementation of solutions to reduce cross-over exposure by using mordanted dyes (e.g. in the process described in European Patent Application No. 101.295) remains unresolved. Some issues are occurring. In fact, the improvement in image sharpness is not only accompanied by a natural decrease in the sensitivity of the photosensitive element due to the absorption of transmitted light, which would have contributed in part to the image formation had it not been absorbed, but also due to the halogenated There is also the risk of desensitization phenomena due to migration of dyes that are not firmly mordanted into the silver emulsion layer. Also, there is a problem of residual contamination even after processing. That is, retention of thiosulfate from the fixing bath causes images to yellow on long-term storage and increases post-processing drying time due to thickening of the components.

Other solutions for reducing overall crossover have also been suggested. I will report it below.

U.S. Pat. No. 3,923,515 discloses placing a relatively less sensitive silver halide emulsion between a support and a relatively more sensitive silver halide emulsion layer to reduce crossover. ing.

U.S. Pat. No. 4,639,411 discloses a low crossover photographic element for use with blue light additive intensifying screens. This element consists of a blue-sensitive halide emulsion layer coated on both sides of a transparent support, and bright yellow silver iodide grains with a unique crystal structure interposed between the support and the emulsion layer. Consists of sexual layers.

Japanese Patent Application No. 62-52546 discloses a photosensitive silver halide emulsion layer coated on both sides of a transparent support, and water-insoluble metal particles with a dye adsorbed on the surface interposed between the support and the emulsion layer. A radiographic element is disclosed that provides improved image quality comprising layers containing the present invention. This dye has an absorption maximum within ±20 nm of the silver halide absorption maximum and corresponds to the light emitted by the intensifying screen. Silver halide is disclosed as a preferred gold and IJ base grain.

Japanese Patent Application No. 62-99748 discloses a photosensitive silver halide emulsion layer coated on both sides of a transparent support, and a substantially non-photosensitive silver halide emulsion layer interposed between the support and emulsion JJ. Rikishima et al. disclose an element for ranography that provides improved FL,TC image quality.

For solutions using a non-light-sensitive silver halide layer as an anti-crossover layer interposed between the support and the light-sensitive silver halide emulsion layer, it is preferred to use Dye-1 PM material. This eliminates several problems such as increased silver coverage and poor bleaching properties (residual contamination) in photographic processing.

Additional documents documenting the current state of the field are available.

Bellyer Patent No. 757,815 discloses the combination of a silver halide matrix and an intensifying screen consisting of a fluorescent compound that emits light at wavelengths less than 410 nm.

In the combination of two fluorescent screens and a double-coated silver halide element as disclosed in U.S. Pat.
nm wavelength range, and the silver halide layer is sensitive to light in the same wavelength range.

U.S. Pat. No. 3.795,814, No. 4.070.58
No. 3 and British Patent No. 2.119.396 disclose rare earth oxybarite phosphors activated with thilium and/or thulium for use in ultraviolet emitting fluorescent screens. ing.

French Patent Application No. 2.264.306 discloses a fluorescent screen consisting of a silver halide element and a rare earth oxyhalide phosphor activated with a rare earth element that has an emission wavelength in the wavelength range of 400-500 nm. A combination with is disclosed.

European Patent Application No. 88,820 discloses that a radiographic phosphor screen comprising a blue-emitting first phosphor layer and a green-emitting second phosphor layer has a spectral sensitivity in the positive range. Disclosed for combination with silver halide elements ("ortho elements").

In the combination of double-coated silver halide elements and screen pairs disclosed in Japanese Patent Application No. 175,000/1980, the phosphor layers of the two screens emit light in different wavelength ranges, and each screen emits light in different wavelength ranges. An organic dye that absorbs the light emitted by the screen? In the combination of a double-sided coated silver halide element as disclosed in EP 8 232,888 containing 1° and a pair of front and back intensifying screens, the front and back screens have the same wavelength. but with a different modulation transfer function (modulation transfer function) for use in low-energy laser zoography.
transfer factor).

U.S. Pat. No. 4,480,024 discloses a combination of a silver halide photothermographic element and a rare earth intensifying screen that are uniquely adapted to each other for industrial runographic imaging. There is. 7 The otothermographic element is dye sensitized to the emission spectrum of the screen, and the combination of screen and element has an overall amplification factor of at least 50. According to the invention, it is preferred to use a single screen in combination with a single-sided coated 7 otothermographic element, but a double screen may be used in combination with a single-sided or double-sided coated photothermographic element. However, the latter has no particular advantage and is accompanied by an increase in the cost of the film.

SUMMARY OF THE INVENTION The present invention is a combination of a pair of radiographic fluorescent screens and a double-sided coated silver halide radiographic element. provide. Each screen is disposed adjacent to each silver halide layer, and each screen is capable of imagewise emitting radiation which, when imagewise exposed by X-rays, sensitizes all adjacent silver halide layers. This combination consists of ten thousand fluorescent screens emitting a second radiation in a first wavelength range of the electromagnetic spectrum, and another ten thousand fluorescent screens emitting a second radiation in a second wavelength range of the t1jIi spectrum. , and each silver halide layer is substantially insensitive to the radiation emitted by the opposing screen.

More particularly, the present invention provides a combination of a pair of front and back radiographic fluorescent screens and a double-sided coated silver halide radiographic element, wherein the first radiation emitted by the front screen is directed to the back screen. The second radiation emitted by the small rx, at least 50
nm different wavelengths and each silver halide layer is substantially insensitive to the radiation emitted by the opposite screen.

More specifically, the invention is a combination of a pair of front and back radiographic fluorescent screens and a double-sided coated silver halide radiographic element, the front screen preferably being non-actinic. a green element wire from a gold-emitting phosphor to a front silver halide layer comprising a silver halide emulsion spectrally sensitized to the element emitted by the front screen; is comprised of a phosphor that emits actinic radiation, preferably ultraviolet light, and is located adjacent to a backside silver halide layer comprising a light silver halide emulsion sensitized to the primary region of the electromagnetic spectrum. The combination is provided.

The combination of fluorescent screen pairs and double-sided coated silver halide elements of the present invention, used in radiography, suffers from significant loss of sensitivity, residual contamination, image instability on storage, and excessive elements. Superior image quality compared to conventional radiographic screen pairs and dual-coated silver halide element combinations, without the negative effects of thickening, increased silver coverage, etc. Provide images with less crossover upwards.

Details of the invention The invention will now be described in detail with reference to the drawings.

The first detail details the combination of an inventive screen pair and a double coated silver halide element.

This combination consists of three separate photosensitive elements.

That is, a double-sided coated silver halide radiography element 10, a front screen 21, and a rear screen 20.
It consists of

As shown, a double coated silver halide radiographic element 10 includes a support 11 and subbing layers 12 and 13 coated on both sides thereof. A front silver halide emulsion layer 15 is coated over subbing layer j-13 and a back silver halide emulsion layer is coated over subbing layer 12 on the opposite side of the support. Silver halide emulsion layer 1
On top of 4 and 15 are protective layers 16 and 17, respectively.
is coated.

As shown, the front radiographic fluorescent screen 21 consists of a support 29, a reflective J+927, a phosphor layer 25, and a protective layer 23.

Similarly, the rear radiographic fluorescent screen 20
consists of a support 28, a reflective layer 26, a phosphor layer 24, and a protective layer 4221.

In practical use, the screen pair and the silver halide element are compressed in a radiographic cassette, with the front screen placed in close contact with the front silver halide emulsion layer and the rear screen IJ- is disposed adjacent to and in close contact with the backside silver halide emulsion layer. The imagewise flow enters the screen pair and silver halide element combination and passes through the front screen support 29 and reflective layer 27 to the front screen phosphor layer 25. Some of the X-rays are caused by fluorophore Jt
Absorbed by S525. The remaining X-rays pass through protective layers 23 and 17. A small portion of the X-rays is absorbed by the front silver halide emulsion layer 15 and thereby directly contributes to latent An k formation in the front silver halide emulsion layer 15. Most of the X-rays pass through the undercoat layer 13, the support 11, and the undercoat M12. However, a small portion of the XM1 is absorbed into the backside silver halide emulsion layer 14 and thus directly contributes to forming a latent image in the backside silver halide emulsion layer 14. D, most of the X-rays are in the a-layers 16 and 2.
2 and is absorbed by the back phosphor layer 24. Image-wise X-rays are mainly absorbed by the phosphor layer 243 and 25.
Vc results in the emission of longer wavelength radiation. According to the invention, the first radiation emitted by the front phosphor layer 25 exposes the adjacent front silver halide emulsion layer 15 and the second radiation emitted by the back phosphor layer 24 exposes the adjacent front silver halide emulsion layer 15. The adjacent backside silver halide emulsion layer 14t-is exposed.

The silver halide emulsion is substantially insensitive to the radiation emitted by the opposing phosphor MK.

At least some of the radiation emitted by the phosphor 1mK passes through the adjacent silver halide emulsion layer, through the subbing layer and the support, and into the opposite silver halide emulsion layer. to expose. This fact has the effect of increasing the sensitivity (8pθ+3(1)) of the combination of screen pair and silver halide element to a certain extent, but impairing image sharpness due to crossover exposure. In the invention, the terms [act, 1nic) J and "non-chemical a (no
The emission JfTa of ``n-actinic)'' is 50, respectively.
Radiation of 0 nm tree droplet length (ultraviolet and evening radiation preferably from 300 nm to b 00 nm length,
And radiation with a pumping length of 500 nm or more? fM (green,
2-piece infrared) good-f t, <U50 Ll ~120
0 mm is used to represent radiation. As used in the present invention, the term "non-photosensitive" refers to the primary or inherent non-sensitivity of a silver halide grain emulsion (or the layers it contains) over a specified range of handling lengths, or double-sided halogenated (a) applied to another emulsion layer(s) interposed between said "non-photosensitive" layer and the radiation-emitting screen; Due to the filtering effect exerted by the filter dyes or agents contained therein, the secondary or induced photosensitivity of the rodanized emulsion (and also the layers it contains) is Therefore, each silver halide emulsion layer contains radiation (preferably 600 to 1200
A latent image formed by exposure (consisting of nm) is emitted onto the phosphor layer adjacent to the phosphor layer 'fc2i! It is formed by exposure with two rays, and the contribution by the opposite screen is not significant. Preferably, the amount of I-ray exposure required to produce a Dmax of 1.0 in the front silver halide layer is less than 0.2 in the back silver halide emulsion layer under the same development conditions.
禾i◇″ will cause hair Dmaz k. Reverse +1
．． λrnax of the back layer resulting in a Dmax k of 1.0
g light-dosage will produce a DmaX of less than 0.2 in the front layer.

It consists of two basic heterocyclic nuclei connected by .

The heterocyclic nucleus preferably contains a fused benzene ring to improve J aggregation.

The heterocyclic nucleus is preferably quinolinium, pen/dexazolium, benzothiazolium, benzoselenazolium, benzo, imidazolium, naphthoxazolium, naphthothiagrilam, and naphthoselenazolium quaternary salts.
Ru.

The J-band type dye preferably used in the present invention has the following general formula (■): (A-)k (B), (ill) where 2 and z2 are the same as -ka or respectively, oxazolines, oxazoles, pendexazoles, naphthoxazoles (e.g., na7' (2e 1 "'")oxazole, naphtho(2,3-4)oxazole, naphtho(1,2-d)oxazole), Thiazoline, thiazole, benzothiazole, naphthothiazoles (e.g., nando(2,1-d) thiar), thiazoloquinolines (e.g., thiazolo(4,5-b)quinoline), selenazoline, selenazole, benzo Selenazole, naphthoselenazoles (e.g. naph) (1,2-4J selenazole), 6H-indole (e.g. 6,6-dimethyl 6H-indole), benzindoles (e.g. 1,1- Cyclic plates derived from basic heterocyclic nitrogen compounds such as dimethylbenzindole], imidacilline, imidazole, benzimidazole, naphthimidazoles (e.g. naph)(2,3-d)imidazolium, pyricine, n and quinoline. Represents an element necessary to complete the above-mentioned nuclear ring 1c is a hydrochloride, herode/(e.g., eva, fluoro, bromo, chloro, io), 3, a furkyl group or a substituted alkyl group (e.g., methyl). , ethyl, propyl, inglovir, butyl, octyl, dodecyl, 2-hydroxyethyl, 6-sulfopropyl, carboxymethyl, 2-cyanoethyl, trifluoromethyl), aryl or substituted aryl groups (e.g. phenyl, 1-naphthyl, 2-naphthyl, 4-sulfophenyl, 3-carboxyphenyl, 4-biphenyl), aralkyl groups (e.g. pen, sol, 7enethyl), alkoxy groups (e.g. methoxy, ethoxy, impropoxy)
, aryloxy groups (e.g. phenoxy, 1-naphthoxy), alkylthio groups (e.g. ethylthio, methylthio), arylthio groups (e.g. phenylthio, p-
tolylthio, 2-naphthylthio], methylenedioxy,
A wide variety of substituents such as cyano, 2-thienyl, styryl, amino or substituted amine groups (e.g. anilino, dimethylanilino, dimethylanilino, morpholino), acyl groups (e.g. eva, acetyl, benzoyl), and sulfo groups More than one group may be present.

Ro and R2 are the same or different and represent an alkyl group, an aryl group, an alkenyl group, or an aralkyl group,
Such groups may be unsubstituted or substituted, for example carboxymethyl, 2-hydroxyethyl, 6-sulfopropyl, 3-sulfobutyl, 4
- Sulfobutyl, 2-methoxyethyl, 2-sulfatoethyl, 6-thiosulfatoethyl, 2-phosphonoethyl, chlorophenyl, bromophenyl.

R3 represents a hydrogen atom.

R1 and R5 are the same or different and represent a hydrogen atom or a lower alkyl group having 1 to 4 carbon atoms.

p and q are equal to 1, however, it is not desirable for both p and q to be 1.

m is U or 1, provided that when m is 1, p and q
both are U-C, and at least 10,000 of zo and z2 represent imidacilline, oxazoline, thiazoline, and 3 represents selenazoline.

A is an anionic group.

B is a cationic group.

k and 1 must be 0 or 1 depending on whether an ionic substituent is present.

Preferably, the phosphors used in the front fluorescent screen applied to the present invention emit radiation in the green or red region of the visible spectrum. More preferably, the phosphor emits radiation in the fringe region of the visible spectrum. Most preferably, the phosphor has more than about 80 wavelengths of its emission spectrum above 480 nm and has an emission maximum at 530 nm.
~570 nm wavelength range. The green light emitting phosphor used in the front fluorescent screen of the present invention is a rare earth activated rare earth oxysulfide of at least one rare earth element selected from IJium, lanthanum, gadolinium, and ruthenium. Phosphor: a rare earth oxyhalide phosphor activated with a rare earth of the same rare earth element; a phosphor made of a borate of the above rare earth element; a phosphor made from a phosphate of the above rare earth element; and a phosphor made of the above rare earth element. It is a phosphor made of mental salt. These rare earth green light emitting phosphors are described in the patent literature, e.g., U.S. Pat.
No. 25,653, No. 3,418,246, No. 3,41
No. 8,247, No. 5,725.7 [No. 14, No. 3, 6
No. 17,743, No. 3,974.389, No. 5.59
No. 1,516, No. 3,607,770 @ 3.66
No. 6.676, No. 3,795,814, No. 4.4 [
J 5.691, No. 4,311.487, and No. 4.387.141.

These rare earth phosphors have high X-ray stopping power (stoppin
gpowθr), and has a high luminous efficiency of the XJ
It makes it possible to use X-ray t-levels.

Phosphors particularly suitable for use in the front fluorescent screen of the present invention include - Formula (1) % Formula % (1) where Ln is at least one selected from lanthanum, gadolinium, and ruthenium. rare earth elements, and a and b are each 0.0005≦a≦0.
A rare earth oxysulfide phosphor layer activated with terbium or terbium-thulium and a general formula (n) (Yl- c-a-b, Lnc, Tba, Tmb) 202
B (If), where Lni-at least one rare earth element selected from lanthanum, gadolinium, and ruthenium, and a, b, and C
are respectively no, oaos≦a≦[J, 09%0≦b≦[
1, [J 1 Oh! U: A rare earth oxysulfide phosphor activated with terbium or terbium mootulicum, represented by U: a number satisfying the condition of 0.65≦C≦o, 95.

Figure 2 shows the emission spectrum of a front fluorescent screen having a fluorescent layer of (()di-0,05j Tb0.05)2028 phosphor as a green light-emitting phosphor, as a function of wavelength (nm) (F). Shown as

According to the invention, the front surface silver halide emulsion layer disposed adjacent to the front fluorescent screen has a spectral range of radiation emitted by the screen, preferably from the wavelength of the emission maximum of the screen. within 25 nm, more preferably within 15 nm, most preferably 10n
It consists of Herodenbuch silver particles that are optically sensitized to a spectral range with intervals of up to m. The silver halide grains in the front silver halide layer are a spectral sensitizing dye (which exhibits an absorption maximum in the visible spectrum region emitted by the front fluorescent screen).
I- Adsorbed on the surface. Preferably, the spectral sensitizing dye according to the invention exhibits J aggregates when adsorbed with VC on the surface of silver heronide particles and has a bathochromically shifted sharpness compared to the absorption maximum of the free dye in the water bath solution. ^ This shows the absorption band (J-E). Spectral sensitizing dyes that produce J aggregates are F,
Cyanin θ Dyes and Related Compounds of Hamor M.
Compounds) (published by John Riley & S/S, 1964) Chapters XVfi, 2 and 4
(Macmillan Publishing, 1977) Chapter 8 is well known for its eclipse.

In the preferred-fLL/-i form, the J band presenting dye is a cyanine dye. Such dyes consist of two basic heterocyclic nuclei linked by a linking group of methine groups. The polycyclic nucleus preferably contains fused benzene rings to improve J aggregation.

The heterocyclic nucleus is preferably quino+7, benzoxazolium, benzothiazolium, benzoselenazolium, benzo, imidazolium, naphthoxazolium, naphthothiazolium, and naphthoselenazolium quaternary. It is grade salt.

J-band type dyes preferably used in the present invention have the following general formula Cm): LA-)k (B1) where zl and z2 are the same or different, and are respectively oxazoline, oxazole, Benzoxazole, naphthoxazole (e.g. naphtho(2,1-d)oxazole, naphtho(2j t-dl oxazole, naphtho(1,2-
a) Oxazole), thiazoline, thiazole, benzothiazole, naphthothian-1-ols (e.g. Nando (
2,1-dJ thiazole), thiazoloquinolites (e.g. thiazolo(4,5-b)quinoline), selenazoline, selenasol 9-ol, benzoselenazole, naphthoselenazole (e.g. nando(l,2-47 selenazolene, 6H-indole (e.g. 6,6-dimethyl 6H
-indole), benzindoles (e.g. 1.1
-dimethylbenzindole), imidacillin, imidazole, benzimidazole, naphthymidaburus (
For example, it represents all the elements necessary to complete the cyclic nucleus derived from a basic heterocyclic nitrogen compound, such as naph)(2,3-a)imidazolium, pyricine, -diσ-norine.

The ring of the nucleus contains hydroxy, herodene (e.g. eva, fluoro, bromo, chloro, io), furkyl group or substituted alkyl group (e.g. methyl, ethyl, propyl, isopropyl, butyl, octyl, dodecyl, 2-hydroxy). ethyl, 6-sulfopropyl, carboxymethyl,
2-cyanoethyl, trifluoromethyl), aryl or substituted aryl groups (e.g. phenyl, 1-naphthyl, 2-f7fl, 4-sulfophenyl, 3-carboxyphenyl, 4-biphenyl), aralkyl Group (
For example, benzyl, 7enethyl, alkoxy groups (e.g., methoxy, ethoxy, impropoxy), aryloxy groups (e.g., phenoxy, 1-naphthoxy),
Alkylthio groups (e.g. ethylthio, methylthio),
Arylthio groups (e.g. phenylthio, p-tolylthio, 2-naphthylthio), methylenedioxy, cyano,
2-thienyl, styryl, amino or substituted amino group (
For example, a wide variety of substituents such as anilino, dimethylanilino, dimethylanilino, morpholino], acyl groups (e.g., acetyl, benzoyl), and sulfo groups.
There may be more than one.

R1 and R2 are the same or different and represent an alkyl group, an aryl group, an alkenyl group, or an aralkyl group,
Such groups may be unsubstituted or substituted, for example carboxymethyl, 2-hydroxyethyl, 6-sulfopropyl, 6-sulfobutyl, 4
-Sulfobutyl 2-methoxyethyl, 2-sulfatoethyl, 6-thiosulfatoethyl, 2-phosphonoethyl, chlorophenyl, bromophenyl-t6.

R3 represents all hydrogen atoms.

R4 and R5 are the same or different and each represents a hydrogen atom, or a lower alkyl group having 1 to 4 carbon atoms.

p and q are O or μm; however, it is not preferable that both p and q be 1.

m is 0 or 1, but when m is 1, p and q
and at least 10,000 of 2 and z2 represent imidacilline, oxazoline, thiazoline, or selenazoline.

A is an anionic group.

B is a cationic group.

k and 1 are 0 or 1 depending on whether ionic substituents are present.

Of course, R and R3, R2 and R5, or R1 and R2 may together represent atoms necessary to complete an alkylene bridge.

A most preferred embodiment of the invention is such that the phosphors of the front fluorescent screen are rare earth phosphors that emit light in the green region of the visible spectrum. In the form, the optical sensitizing dye adsorbed to the silver halide grains of the front silver halide layer is generally (■) [wherein RIO is a hydrogen atom or a carbon atom having 1 to 1 carbon atoms] 4 represents a lower alkyl group (for example, methyl, ethyl), and R6, R7, R8, and R2 each represent a hydrogen atom, a
) f atoms (e.g., chloro, bromo, iodo, fluoro), hydroxy groups, alkyl' groups (e.g., methoxy, ethoxy-amino groups (e.g., amino, methylamine, dimethylamino), acylamino groups (e.g., Acetamide, propionamide], acyloxy group (e.g.
acetoxy group), alkoxycarbonyl group (e.g. methoxycarbonyl, ethoxycarbonyl, butoxycarbonyl), alkyl group (e.g. methyl, ethyl, inglovir), alkoxycarbonylamino group (e.g. tl
'f, ethoxycarbonylamino), or an aryl group (e.g., phenyl, tolyl); (so that the heterocyclic nucleus is e.g. an α-naphthoxazole nucleus, a β
-naphthoxazole, or β, β'-naphthoxazole], R, and R are each an alkyl group (
For example, methyl, propyl, butyl), hydroxyalkyl group C example, t[,2-hydroxyethyl, 6-hydroxyethyl, 4-hydroxybutyl), acetoxyalkyl group (e.g. 2-acetoxyethyl, 4-acetoxybutyl) , alkoxyalkyl groups (e.g., 2-methoxyethyl, 3-meth)$dipropyl], carboxyl group-containing alkyl groups (e.g., carboxymethyl, 2-carboxyethyl, 4.-carboxybutyl, 2-(2-carboxyethoxy) )-2, thyl], sulfo group-containing furkyl i (e.g. 2-sulfoethyl, 6-sulfopropyl, 4-sulfobutyl, 2-hydroxy-3-sulfopropyl, 2-(3-sulfopropoxytuflovir, p-
sulfobenthyl, p-sulfophenethyl], benzyl group, phenethyl group, vinylmethyl group, and the like; , ethyl sulfate ion, perchlorate ion, p-toluenesulfonate ion), and n represents 1 or 2.

The above substituents R6, R7, R8, Ro, R. and R□
, the number of carbon atoms in the alkyl group included in The number of atoms in each group is preferably 1 to 12, more preferably 1 to 4, and the total number of carbon atoms contained in the above group is preferably 1 to 20.

The number of carbon atoms in each of the aryl groups included in the substituents R6, R7, R8,2 and Ro is preferably 6 to 1.
B, preferably ii6 to 10, and the total a of carbon atoms contained in the group is up to 20.

Above - J belonging to the formula (denoted by IVNC)
A specific example of the sensitizing dye for the band is shown below: Dye RIOR6RF
R8Fb Ru Rtz
nA C2H5H5-CI HsiQ(G(2)3sO
3-(12)3803H-1B"C2H5H5-CIH
5'C3H5(C5i2)3803- CG(2)2C
Fa3H-IC(E, H5-OC%!(5 pigeon C2E
5((I(2)3sQ, --1D C2H56-C5
i3 5-alu, 5'-c:t (CH2 people 803
((R2)3SO3H-1" triethylamine salt special sodium salt Figure 6 shows the spectral sensitivity of the front silver halide layer consisting of silver iodobromide grains with a silver iodide content of 2.6 mol % at wavelength (nm). ) Expressed as sensitivity (s) to VC.

Preferably, the phosphor used in the back fluorescent screen applied to the present invention emits radiation in the ultraviolet region of the electromagnetic spectrum. More preferably, the phosphor has more than about 80% of its emission spectrum below 410 nm, and its emission maximum is in the wavelength range of 600 to 360 nm. The ultraviolet emitting phosphors used in the back fluorescent screen of the present invention are lead or lanthanum activated barium sulfate phosphors, barium fluorohalide phosphors, lead activated barium silicate phosphors. , gadolinium activated yttrium tomooxide phosphor, barium fluoride phosphor, alkali metal activated t1. Known ultraviolet emitting phosphors such as niobium or tantalate phosphors. UV-emitting phosphors are e.g.
7 for iF [J 5,998 and 757.815
No. 2, European Special IF No. 2 Ll 2.875, and the paper by Buchanan et al.
Op Agenoid Fix (J.

Appliθd Physics) No. 90 No. 4642
~4647 pages (1968), and Tarap (C1a
pp ) and Zenday (Gintb13r) Papers Journal of the Optical Society of...
America (J, of the 0ptical Sa
c, of America) No. 37 @ No. 655-6
62 (1947). Particularly preferred UV-emitting phosphors for use in the rear fluorescent screen of the present invention are those represented by the general formula (V): CYl-27sx-1/3ya 5rxjLiy) T
a04 However, X and y are European Patent 8S21J 2j8
As described in No. 75, the number satisfies the conditions of 1o-5≦X≦1 and 10-4≦y≦U, 1.

Figure 4 shows the emission spectrum of a backside fluorescent screen CD with a phosphor layer of (Y, Sr, Li) 'I'a04 fluorophores as ultraviolet emitting phosphors.
It is expressed as fluorescence (S) versus wavelength (nm).

The rear silver halide emulsion layer which is placed in accordance with the present invention in contact with the rear screen Vc of the actinic radiation-emitting phosphor is not optically sensitized, but rather is a photosensitive silver halide emulsion layer of known type. It consists of silver halide grains with a spectral sensitivity of . It is known that the inherent spectral sensitivity of the conventional silver halide grains used in 0L5VC photographic film is OK in the ultraviolet and backlight regions of the electromagnetic spectrum. It is surrounded by

Figure 5 shows the spectral sensitivity of the backside silver halide emulsion layer consisting of silver iodobromide grains with a silver iodide content of 2.3 mol % and no optical sensitizer adsorbed on the surface. nm,)
It is expressed as sensitivity (S) with respect to Ic.

According to the invention, the non-actinic radiation (preferably green light) emitted by the front screen consists of silver halide grains that are spectrally sensitized to the radiation emitted by the front screen. Imagewise exposing the adjacent front side silver halide layer. Some of the non-actinic radiation μ reaches the back side silver halide no VC, but the silver halide grains in the back side silver halide layer? No crossover exposure. For example, ;f:fJ- particles are not spectrally sensitized to the radiation emitted by the front screen.

The ultraviolet or blue light emitted by the back fluorescent screen is absorbed by the adjacent backside silver halide grains and imagewise exposes the silver halide grains that have not been optically sensitized. There is rather no crossover through to the opposite front silver halide layer. This is due to the fact that silver halide grains exhibit good intrinsic absorption for light with a wavelength of less than 500 nm, and moreover, ultraviolet and blue light are strongly scattered by the silver halide grains dispersed in the emulsion layer. This means that a large amount of ultraviolet or blue light from the back fluorescent screen exposes and bends the silver 9nide layer to the opposite front surface. The screening pairs and double-sided silver halide elements according to the invention are coarsely divided by:
Compared to the conventional coarse separation of a pair of green light-emitting fluorescent screens and a double-sided coated green light-sensitized silver halide radiographic element, the crossover exposure is preferably at least 10 meters;
More preferably it is reduced by at least 20%. Thus, image sharpness is improved by reducing cross-over exposure through the unique coarse separation of the conventional silver halide emulsion layer and the fluorescent screen.

The photosensitive double-coated silver halide radiographic element comprises a transparent polymer base of the type conventionally used in radiography, such as a polyester base, especially a polyethylene terephthalate base.

In the silver helodenide photographic element of the present invention, a silver halide emulsion is coated on both sides of the support, namely a spectrally sensitized silver halide emulsion on the front side and a spectrally unsensitized silver halide emulsion on the back side. may be the same or different and include emulsions commonly used in photographic elements, such as silver chloride, silver iodide, silver chlorobromide, silver chloroiodobromide, silver bromide, silver chloride, etc. Consists of chemical silver. Silver bromide is particularly effective for radiographic ixo. Silver herodenodide grains can have a variety of shapes. For example, a cube,
It may have an octahedral or plate-like shape, or may be grown by epitaxial growth. They are generally 0.1 to 6 μm
, more preferably an average size in the range of 0.4 to 1.5 μm. The emulsion is coated onto the support at several full silver laydowns ranging from about 6 to 69/horse. The silver halide material used is a water-permeable hydrophilic colloid, preferably gelatin, but also other hydrophilic colloids, such as gelatin derivatives, albumin, polyvinyl alcohol, alyanates, hydrolyzed cell O-X esters. ,
Hydrophilic polyvinyl polymers, dextran, polyacrylamide, hydrophilic acrylamide copolymers or alkyl acrylates can also be used alone or in bulk with gelatin.

Research Disclosure 18431 (published August 1979) is a good reference for information on how to create silver halide emulsions and the use of specific ingredients in emulsions and in light-sensitive elements. Described: IA, Processes for the preparation, purification and condensation of silver halide emulsions, Type Ic of emulsions, Chemical sensitization and doping of crystals, Stabilizers, anti-capri agents, and antifolding agents. ) ■ A. Stabilizers and/or anti-capri agents [B. Stabilization of emulsions chemically sensitized with gold compounds ■ Stabilization of emulsions containing C0 polyalkylene oxides or plasticizers IID, IIE, ■ Do... ■G.

1[H. II. Additives for developers containing anti-capri additives to minimize desensitization due to folding Anti-capri agents for emulsions coated on polyester bases Methods for stabilizing emulsions under light Access )
Methods for stabilizing X-ray materials used in roller processor transfer processing Transformation and antistatic layer Protective layer Direct tenon material Room Materials for processing under light Spectrally sensitized UV-sensitive materials ■, Base The helodenized photothermographic element of the present invention basically consists of a non-photosensitive reducible silver source, a photosensitive material that produces silver when irradiated, and a Consists of reducing agent. Generally, the photosensitive material is a photographic silver halide and must be in catalytic proximity to the non-photosensitive silver source.

Catalytically proximate means that when silver specks or nuclei are produced by irradiation or exposure of photographic silver halide, those nuclei are capable of catalyzing the reduction of the silver source by the reducing agent. This means that the two materials are in close physical association. Silver is a catalyst for the reduction of silver ions, and the catalyst generator, silver-forming photosensitive 710 silver denoide, can be placed in catalytic proximity to the silver source in a number of different ways. can. For example, No.1
Partial metathesis of a silver source by a source containing 0 K1 (e.g., rice 1
No. 3,457,075], co-precipitation of silver rodenide and a silver source material (for example, U.S. Patent No. 3,839.LI
No. 49], there are other methods that closely combine silver halide and silver sources.

The silver source used in this technical field is a material containing a source of reducible silver ions. Early and still preferred silver sources were long chain aliphatic carboxylic acids (usually containing 10 to 6 carbon atoms).
0). BehenrR'! silver salts or mixtures of acids of similar molecular weight have been primarily used. Other organic substances such as salts of other organic acids or silver imidazolates have also been proposed, and UK 4Lf [1,1111J
, No. 046 Vcld, discloses the use of complex salts of inorganic or organic silver salts as image source materials. Silver salts of long chain (10 to 30, preferably 15 to 28 carbon atoms) aliphatic carboxylic acids are preferred in the practice of this invention.

Photothermographic emulsions are usually constructed as one or two layers per side of the support. The single layer structure includes a silver source material, silver halide, a developer, a binder, and optionally additives such as toning agents, coating aids, etc.
It must contain other auxiliaries. A two-layer structure must contain the silver source and silver halide in one emulsion layer (usually the layer adjacent to the support) and other components in the second layer or both layers. Barahiko.

The silver source material should constitute about 20-70% by weight of the imaging layer. Preferably it is present as 60-55% by weight. The second layer in a two-layer structure will not affect the proportion of silver source material required in the single-layer imaging layer.

The silver halide can be any photosensitive silver halide, such as silver bromide, silver iodide, silver chloride, silver iodobromide, silver chloroiodobromide, silver chlorobromide, etc., and the silver source It may be added to the emulsion layer in any manner such that it is placed in catalytically close proximity to the emulsion layer. Silver halide is generally 0.75% in the imaging layer.
It is present as ~15% by weight, but larger amounts are also effective.

It is preferable to use silver halide in the image forming layer in a total amount of 1 to 10%, and 1.5 to 7. It is most preferable to use []% by weight. An extensive list of photographic and processing aids can be used in the preparation of silver halide emulsions. These materials are chemical sensitizers (including sulfur and gold compounds)
, development accelerators (e.g. onium and polyionium compounds), alkylene oxide polymer accelerators, antifogging compounds, stabilizers (e.g. adende/, especially tetra- and pentaazoindene), surfactants (in particular,
fluorinated surfactants), antistatic agents (especially fluorinated compounds), plasticizers, matting agents (matzingagenz
) etc.

The reducing agent for silver ions can be any substance that can reduce silver ions to gold, metal, and silver, but it is a good choice. Conventional photographic developers such as phenidone, hydroquinone, and catechol are effective, but hindered phenol reducing agents are preferred. The reducing agent should be present between 1 and 20" of the imaging layer.2
In the M structure, if the reducing agent is present in the second layer, a slightly higher proportion, about 2-20%, appears to be desirable.

Toning agents such as phthalazinone, phthalazine, and phthalic acid are not essential components, but are highly desirable. These materials may be present in amounts of, for example, 0.2 to 5 parts by weight.

The binder may be selected from any of the well-known natural and synthetic resins such as gelatin, polyvinyl acetal, polyvinyl chloride, polyvinyl acetate, cellulose acetate, polyolefins, polyesters, polystyrene, polyacrylonitrile, polycarbonate, and the like. Of course, these definitions include copolymers and terpolymers. Particularly desirable are polyvinyl acetals such as polyvinyl butyral and polyvinyl formal, and vinyl copolymers such as polyacetate/salts. The binder may have a coulometric value in the range of 20 to 75 in each layer, preferably about 60
~55 weight! It is used in the range of t%.

As mentioned above, various other auxiliary agents may be added to the photothermographic emulsions of the present invention. For example, toning agents, accelerators, acutance
ce) Dyes, sensitizers, stabilizers, surfactants, lubricants, coating aids, antifoggants, leuco dyes, chelating agents, and various other well-known additives may commonly be incorporated. The use of acutance dyes that match the emission spectrum of the intensifying screen is particularly desirable.

The balance of properties in photothermographic emulsions must be precisely regulated by the proportions of materials in the emulsion. The ratio of silver salt to organic acid is particularly critical to obtain the necessary centometric properties in photothermographic cables for use in radiography. In typical photothermographic emulsions, nearly pure salts of organic acids (e.g., mixtures of behenic acid, stearic acid, and long-axis acids)? It is commonly used as a substantial component of emulsions. Sometimes small or relatively large amounts of acid components are included in the emulsion. In the practice of this invention, the molar ratio of organic silver salt to organic acid must be in the range of 1.571 to 6.2/1 (salt/acid). It has been found that below this range the contrast is too low, and above this range the emulsion stability and background stability drop unacceptably.

Preferably, this ratio is in the range 2.0/1-3.50/1.

Silver halide is supplied by in-situ halogenation or by the use of pre-formed silver halide.

Industrial radiography processes may be performed using conventional x-ray sources (or other high-energy particle sources, including r-ray sources and neutron sources).

As is well known, the particular phosphors used have a high absorption coefficient for the radiation generated by the radiation source. usually,
This radiation is a red energy particle beam that can be defined as either an X-ray, a neutron beam, or an R-ray. The industrial material should be placed between the controllable X-ray source and the industrial radiography system of the present invention. Controllable X-ray exposure from the radiation source through the industrial material.

The surface of the intensifying screen should be incident at an approximately perpendicular angle to the surface and the photothermographic film tangent to the inside of the screen. The radiation absorbed by the screen's photoreceptors should be emitted by the screen, and the light should then form a latent image on the silver halide grains of the two halide layers. Conventional thermal imaging would then be applied to this exposed film.

The present Q-light X-ray image conversion screen has a phosphor layer consisting of a binder and a phosphor dispersed therein. The entire phosphor layer is coated by dispersing the phosphor in a binder to form a coatable dispersion and then applying the coatable dispersion to a uniform 1Δ by conventional coating methods. When the fluorophore layer is self-supporting, it is possible to construct a radiation image conversion screen using the fluorophore layer, but generally the fluorophore 1→ is provided on a support and the radiation iK! Configure the image conversion screen. 6. Furthermore, a protective layer for physically and chemically protecting the fluorescent layer is usually provided on the surface of the fluorescent layer. In addition, a subbing layer may be provided between the phosphor layer and the support in order to bond the phosphor layer closely to the support, and a subbing layer may be provided between the phosphor layer and the support (or lower Ig layer) and the phosphor layer. A reflective layer may also be provided in between.

The binder used in the firefly layer of the X-ray image converting screen according to the invention can be, for example, one of the binders customary for the formation of scraps, such as arabic yam, proteins such as piratin, polysaccharides such as Dextran, organic polymer binder such as polyvinyl butyral, polyvinyl acetate, nitrocellulose, ethylcellulose, vinylidene chloride-vinyl chloride copolymer, polymethyl methacrylate, polybutyl methacrylate, vinyl chloride-vinyl acetate copolymer, polyurethane, cellulose acetate butyrate , polyvinyl alcohol, etc.

Generally, the binder is 0.0
It is used in an amount of 1 to 1 part. However, from the viewpoint of the sensitivity and sharpness of the resulting screen, it is preferable that the amount of binder is small. Therefore,
Considering both the sensitivity and sharpness of the screen and the ease of application of the coatable dispersion, it is preferred that the binder is used in an amount of 0.05 to 0.2 parts by weight per part by weight of phosphor. The thickness of the firefly layer is generally in the range of 10 microns to 1 micron.

In the radiation image converting screen of the invention, the fluorescent layer is generally coated on a support. A variety of materials can be used as the support, such as polymeric materials, glass, wool, cotton, paper, metal frames, etc. Due to screen handling considerations, the substrate should preferably be processed into a flexible sheet or roll.

In this connection, supports may be plastic films (such as cellulose triacetate films, polyester films, polyethylene terephthalate films, polyamide films, polycarbonate films, etc.) or plain or processed papers (photo paper, baryta paper, resin-coated paper, etc.). paper, pigment-containing paper containing pigments such as titanium dimonide, etc.) are preferred. The support may have an undercoat layer on the negative side (the surface on which the fluorescent layer is provided) of the Pf support for the purpose of firmly holding the entire fluorescent layer. Undercoat! As the material for -C, a normal adhesive can be used. To form a phosphor layer on a support (or on a subbing layer or on a reflective layer), a coatable dispersion consisting of a phosphor dispersed in binder is applied to the support (or on a subbing layer or on a reflective layer). or reflective layer).

Furthermore, in the X-ray image conversion screen of the present invention,
On the surface of the fluorescent layer to be printed (opposite to the support for 1 hour)
11), a protective layer for physically and chemically protecting the entire fluorescent layer is provided at -G'. As mentioned above, if the phosphor layer is self-supporting, the protective layer may be provided on both sides of the phosphor layer. (protection) may be provided on the fluorescent layer by applying a coating dispersion that becomes a protective layer on the fluorescent layer 7, or
Alternatively, it may be provided by bonding to a previously formed protective 1-total fluorescent layer. The material for the protective layer is
Common protective layer materials such as nitrocellulose, ethylcellulose, cellulose acetate, polyester, polyethylene terephthalate, etc. can be used.

The X-ray image conversion screen of the present invention may be colored with a coloring agent. Furthermore, the fluorescent layer of the radiation image conversion screen of the present invention may contain white powder dispersed therein.

By using colorants or white powders, it is possible to obtain radiation image converting screens that give images of high sharpness.

Examples The present invention includes the following specific examples and comparative studies? I can explain it better by referring to it.

(Gd]-0,0!l ・Tb with average particle size 6 μm
o, o5) A high resolution green light emitting phosphor screen or screen GR8,i was prepared coated on a 2028 star support. A reflective layer consisting of titanium dioxide particles in a polyurethane binder is coated between the phosphor layer and the support. This screen is coated with a cellulose triacetate layer.

Green light-emitting phosphor Screen GR82 average particle size 4 μm (Gdx-o, os s Tb0.05) 20
28 Fluorescent material coated in a hydrophobic polymer binder! 480.9/-1", 120 μm thick, and coated on a polyester support, a medium resolution green light emitting phosphor screen or screen GR82k was prepared. Between the phosphor layer and the support The screen is coated with a reflective layer consisting of titanium dioxide particles in a polyurethane binder.The screen is overcoated with a layer of cellulose triacetate.

Type NP-304 [ ] (Y * 8r * Ll) of Nichia Chemical Industries, Ltd. with an average particle size of 5.1 μm
) Ta04 fluorophore? UV-emitting phosphor screen or screen UVS, t-, coated on a polyester support in a hydrophobic polymeric binder with a phosphor coverage of 45097 rlL2 and a thickness of 110 μm.
Created. A reflective layer consisting of titanium dioxide particles in a polyurethane binder is coated between the phosphor layer and the support. The screen is overcoated with a layer of cellulose triacetate.

A green light sensitized silver halide emulsion layer (hereinafter referred to as the front layer) coated on one side of the support and a non-spectrally sensitized silver halide coated on the other side of the support. A photosensitive film having an emulsion layer (hereinafter referred to as back layer), namely C) RUVF 1, was prepared as follows. On one side of the polyester support, cubic silver iodobromide grains (2.6 mole fraction of silver iodide and an average grain size of 0.5 molar fraction of silver iodide) are deposited.
65μmf)? A green light sensitized 710 silver denide gelatin emulsion layer was coated containing silver 2.571/rlL'' and gelatin 1,S!?/rPL''. The emulsion was chemically sensitized with sulfur and gold and contained 1070 μg of green light sensitizing dye A or anhydro-5 per mole of silver.
+ 5'-dichloro-9-ethyl-6,6'-bis(3
-sulfopropyl)-oxacarbo/anine hydroxide triethylamine salt. The silver iodobromide front layer was completely overcoated with a protective layer containing 0.9 g/m' of gelatin.

On the other side of the polyester support, cubic silver iodobromide grains (2 mol of silver iodide and an average grain size of 1.3
a 1:1 blend by weight of silver iodobromide grains having a particle size of 2.6 molar silver iodide and an average grain size of 0.65 μm). Unsensitized silver halide gelatin emulsion layer t
-1 silver 2.51 g/rn2 and gelatin 1.89/rn2
The emulsion was chemically sensitized with sulfur and gold.The silver iodobromide back layer was coated with gelatin 70-
The entire overcoat layer contains 99/m2.

A green light sensitized silver halide emulsion layer coated on one side of the support (hereinafter referred to as the front layer) and a spectrally unsensitized silver halide emulsion layer coated on the other side of the support. A photosensitive film containing a silver emulsion layer (hereinafter referred to as back layer), i.e. film GT(υVF2'), was prepared as follows: on one side of the polyester support, on the front side of film GRUVF 1 Cubic silver iodobromide grains (2.6 molar silver iodide and average grain size 0.6
A green light sensitized silver halide gelatin emulsion containing t:d with silver 2.609/IjL"
and gelatin 1.9". The emulsion was chemically sensitized with sulfur and gold and coated with silver 1.
Spectrally sensitized with green photosensitizing agent A, anhydro-5,5'-dichloro-9-ethyl-3,6'-bis(6-sulfopropyl)-oxacarbocyanine hydroxide triethylamine salt, at a molar volume of 1070 μm. ing.

In the silver iodobromide front layer, gelatin 0.9 g/rI
A protective layer containing Lz was overcoated. The other side of the polyester was spectrally sensitized containing cubic silver iodobromide grains (having a silver iodide mole ratio of 2.6 and an average grain size of 0.65 μsf) used in the front layer of the film C) RUVF□. A silver halide gelatin emulsion layer containing 2.49 g/m of silver and 1.9 F/FA of gelatin.
The emulsion was chemically sensitized with sulfur and gold.The back layer of the iodobromide film was coated with 0.911 gelatin.
7m''I: Overcoated the containing protective layer.

Light-sensitive photographic film UVUVF3 A light-sensitive film having non-spectrally sensitized silver halide emulsion layers coated on both sides of a support, i.e. UVU
Cubic silver iodobromide grains (having a silver iodide mole ratio of 2.6 and an average grain size of 0.65 μmf) used in the film G'RUVF 1 were placed on each side of a polyester support as follows. A spectrally sensitized silver halide gelatin emulsion layer containing silver 2.
It was applied at 60g/m2 and 2.49.9/rn2 and gelatin:/1.9E/77L2. This emulsion was chemically sensitized with sulfur and gold. Each silver iodobromide layer was overcoated with a full protective layer containing gelatin 0.9.9/K2.

A green light sensitized silver halide emulsion layer coated on both sides of the support overlying photosensitive film, i.e. GRGRF.
4' was prepared as follows. Both sides of the polyester support contained green light sensitized halogenated cubic silver iodobromide grains (with iodine, silver oxide 2.6 molar fraction and average grain size 0.65 μm2) used in the front layer of the GRUVF coating. The silver gelatin emulsion layer was coated with silver 2.18. ! i'/r
IL2 and gelatin were coated at 71.9 g/m2. This emulsion was chemically sensitized with sulfur and gold and had a green light sensitizing dye A, anhydro-5,5'-dichloro-9-ethyl-3,6'-bis(3 -sulfopropyl)-oxacarbocyanine hydroxide triethylamine salt. Each silver iodobromide layer was overcoated with a protective layer containing 0.9 g/7712 gelatin.

Combination of screen pair and photosensitive photographic film The pair of screens described above and the double-sided coated photosensitive photographic film were combined and exposed as follows. A film-screen combination was torn, with the front screen in contact with the front emulsion layer and the back screen in contact with the back emulsion layer, as shown in FIG. Each clean pair-film combination was exposed to X-rays from a tungsten target tube operated at 80 kVp and 25 mA, with a 120C7n blast. The x-rays passed through an aluminum step wedge before reaching the screen-film combination.

After exposure film gold, 3M XAD/2 developer replenisher and 3M XAF/2 fixer replenisher all used 3
M To IJ M Deck Processed with XP507 processor.

Sensitivity and image quality are reported in the table below. The crossover factor was calculated using the following formula: where δlog E is the sensitivity difference between two emulsion layers of the same film when exposed using a single screen. (The lower the crossover ratio, the better the image quality.

) The sharpness and granularity of the screen-to-film combination was determined as follows. Each screen versus film union Jf! :'t-18Q kVp and 25mA
X + li from the tungsten tube operated by , distance 15
Exposure was performed at 0C171. Before reaching the screen-film combination, the
) Passed through Tarded. i4 light film, 3M
XAD/2 developer replenisher and 3M XAF
/2 3M to use all fixer replenisher solution! Processed with a JM Chic XP507 processor.

The sharpness and granularity of the processed films were determined by visual inspection by 10 examiners skilled in image comparison. Figures 6 and 7 plot the sharpness (S[) and granularity (GR) against the sensitivity (δS) of the double-coated silver halogenated element and fluorescent screen pair combination; For reference, the sensitivity difference of a green-sensitive double-coated element combined with a pair of green light-emitting fluorescent screens is shown. In these graphs, the higher the value, the better the sharpness and granularity. UV-sensitive and '#-sensitive double-coated silver halide elements when combined with a UV-emitting fluorescent screen pair have the best sharpness and granularity;
Sensitivity is low. On the other hand, the double-coated element and screen pair combination according to the present invention has a sensitivity comparable to or better than, superior to, or comparable to a green-sensitive double-coated element in combination with a green light-emitting fluorescent screen pair. Indicates ridge sharpness and granularity.

Light-sensitive photothermography film RBLF5 a) Production of silver soap 634.5,! IFumbo acid (IFumbo acid) 9022 (90 cm of C20" C22, 5 cm of C1B, and 5 parts of its I1
131g of humpoic acid 9718 (a long-chain fatty acid carboxylic acid consisting of 95% C1B and 5% C16), and 0.44 mol of 0.0
An 8 μm cubic silver iodobromide (6 mol % silver iodide) emulsion was completely added. 89.18. was dissolved in 1.257' of water while stirring. fi' of 19 ml of sodium hydroxide was added and then aerated with 50 ml of water. 1 Salt was added with counterfeit money. It was dissolved in 2.51 of water at 55°C.3 64.
8.9 silver nitrate? , added at 55°C. All of this hardware was slowly stirred at 55°C for 1 hour until the water resistance was 20°C.
The sample was centrifuged while being sprayed and washed until it became 000Ω, then dried for ζ1 hour.

b) Production of silver salt homogeneous product The above silver soap powder (12 parts by weight) and toluene (20 parts by weight) were mixed together.
Fa) and methyl ethyl ketone (6a: ton ■%) were mixed together, soaked overnight, and 12 g of polyvinyl butyral [ButWar A/ (ButWar) TMB-76] was mixed.
and at 4,000 PSI, then 8,
Homogenized at 000 PSI.

C) Preparation of the first trip To 200 g of the above silver soap homogenate were added 40.51 methyl ethyl ketone and 30 g of polyvinyl butyral (B-76) and mixed for 1 hour. To this mixture was added 20% mercuric bromide 10% in methanol.
．． 2 ml was added, stirred for 5 minutes, then 49 g of Nonox W 50 fQ iron agent of formula % was added.

The above dispersion 50. In the first part of S', 10d portrait 0
．． 6 ml of a solution of the following blue light sensitizer of 11/I9 was added to the second part of the recorded material 50.9. A solution of Q, 6m
6 added: CH2C00Na component weight parts d) First Trip Application The above blue light sensitized dispersion was added to a clear 4 mil (2X 1
．． 0-'m) on a polyethylene terephthalate support +CS mill thickness and dried at 87°C for 6 minutes. The opposite side of the support was coated with the above green light sensitized dispersion at a thickness of 5 mils and dried at 87°C for 3 minutes.

e) Directly behind the nitrite tube A, methyl ethyl ketone 78.58B
, acetone 12.02C,
Methanol 4.91D,
FC-431 (3M fluorocarbon) 0
．． 04E, Phthalazine 0.
59F, 4-methyl-phthalic acid 0.
41G, tetrachlorophthalic anhydride 0.
27 Skin Tetrachlorophthal tl O,
12th grade, cellulose acetate ester 3.
06 container and mixed them all until the solids were electrolyzed. It was then added to T' and mixed for 1 hour until dissolved.

f) Apply a second trip' to a 2.25 mil thick coating on top of the blue light enhancing, seductive coating applied to the frfJ Nitrib coating and heat at 87°C for 6 minutes 17 minutes.
jl Dried. The film was reversed, and a total of 2.25 liters of nitrite was applied on top of the previously applied green light sensitized coating.
It was applied to a mill and incubated for 3 minutes at 87°C.

ε 2) Film evaluation completed F1″ Kushino ζ double-sided Ranbu 7 Otothermography E-Mon film sample gold xenon flash sensitometer by % 460 nm Kyo band filter KA
and bubbled through a continuous density wedge from 0 to 4 with a 10-3 second revision. Exposed sample roller W
:i,'b Treated with thermoprocessor at 131°C for 41 minutes. Centometry is Dmin = O-21:
td work l)ma! It was recorded as -4-22. The quaternary '''iiL images were processed as above with another Temple'x 530 nm narrow band filter. Sensitometry was performed with Dmin == 0-21 and Dmax =
2-19 and 80 recorded nine. The crossover from the greyscale-sensitized layer to the f-sensitized layer is clearly not reassigned. The blue light sensitized layer when coated alone on one side of a polyester support produced the following image:D
Engineering □. = 0.13 and DInax = 2.56°

[Brief explanation of the drawing]

Figure 1 shows a schematic diagram of the combination of a radiographic element and a screen pair according to the present invention. Figures 2 and 4 show the emission spectra of the radiographic fluorescent screen of the present invention -F (3rd, 1st and 5th south) is a graph showing the fractional sensitivity of the town surface coated halogenated geography element of the present invention. Figures 6 and 7. is a combination of screen coating halo for radiography) rlin conversion 903 and screen pair-! It is a graph showing (7) the relationship between sharpness and granularity with respect to sensitivity change.

Claims (28)

[Claims] (1) A silver halide radiographic element consisting of two independent front and back X-ray fluorescent screens and a support base and front and back silver halide emulsion layers coated on both sides of the support. the front screen is positioned adjacent to the front silver halide layer, and the back screen is positioned adjacent to the back silver halide layer, and i) the front screen is a first radiation-emitting layer. a phosphor, and said front silver halide layer comprises silver halide grains sensitive to said first radiation emitted by said front screen, and ii) said back screen comprises a first radiation emitting layer. A combination of photosensitive elements for use in radiography, comprising a phosphor, and said rear silver halide comprising silver halide grains sensitive to said second radiation emitted by said rear screen. a) the first radiation emitted by the back screen is in the non-actinic wavelength range, and the second radiation emitted by the back screen is in the actinic wavelength range; b) the first radiation emitted by the front screen has a wavelength that differs by at least 50 nm from the second radiation emitted by the back screen, and c) the front silver halide the emulsion layer is substantially insensitive to the second radiation emitted by the back screen; and d) the back silver halide emulsion layer is substantially insensitive to the second radiation emitted by the front screen. characterized in that it is substantially insensitive to one radiation, and thus the difference in the wavelength range of said first and second radiation, and each halogen to the radiation emitted by the opposite screen. The non-photosensitivity of the silver oxide layer is
The combination is such that the cross-over exposure is reduced by at least 10% compared to a symmetrical combination of a pair of green light-emitting fluorescent screens and a dual-coated green light-sensitized silver halide radiographic element. (2) a) said front screen comprises a phosphor emitting non-actinic radiation, and said front silver halide layer comprises a halogen spectrally sensitized to the radiation emitted by said front screen; and b) the back screen is made of a phosphor that emits ultraviolet light, and the back silver halide layer is made of silver halide grains that are not spectrally sensitized. combination body. 3. The combination of claim 1, wherein said front screen consists essentially of a green light emitting phosphor. (4) The front screen has an emission spectrum of 8
More than 0% is 480 nm or more, and the emission maximum is 5
A combination according to claim 1, comprising a green light-emitting phosphor in the wavelength range of 30-570 nm. (5) The front screen has the general formula (Ln_1_-_a_-_b'Tb_a'Tm_b)_
2O_2S (wherein Ln is at least one rare earth element selected from lanthanum, gadolinium, and ruthenium, and a and b are each 0.0005
≦a≦0.09 and 0≦b≦0.01), or the general formula (Y_1_-_c_-_a_-_b'Ln_c'Tb_
a'Tm_b)_2O_2S (in the formula, Ln is lanthanum,
at least one rare earth element selected from gadolinium, and ruthenium, and a, b, and c
are 0.0005≦a≦0.09, 0≦b≦0.
01 and 0.6 (a number satisfying the condition of 5≦c≦0.95). (6) The front screen has a wavelength of substantially 487 nm and 5 nm.
A combination according to claim 1, comprising a terbium-activated gadolinium or lanthanum oxysulfide phosphor having an emission peak at 45 nm. (7) The combination of claim 1, wherein the front silver halide layer comprises silver halide grains spectrally sensitized with a cyanine or merocyanine dye spectral sensitizing dye. (8) The front silver halide layer has a thickness of 530 to 570 nm.
5. The combination according to claim 4, comprising silver halide grains spectrally sensitized with a spectral sensitizing dye so as to be sensitive to light in the wavelength range of . (9) The front silver halide emulsion layer has the general formula ▲ mathematical formula,
There are chemical formulas, tables, etc.▼ (In the formula, R_1_0 represents a hydrogen atom or an alkyl group, and R_6, R_7, R_8, and R_9 each represent a hydrogen atom, a halogen atom, a hydroxy group, an alkoxy group,
represents an amino group, an acylamino group, an acyloxy group, an alkoxycarbonyl group, an alkyl group, an alkoxycarbonylamino group, or an aryl group, or each R
_6 and R_7, and R_8 and R_9 may be atoms necessary together to complete a benzene ring, and R
_1_1 and R_1_2 each represent an alkyl group, a hydroxyalkyl group, an acetoxyalkyl group, an alkoxyalkyl group, a carboxyl group-containing alkyl group, a sulfo group-containing alkyl group, a benzyl group, a phenethyl group, or a vinylmethyl group, and X^- is 5. A combination according to claim 4, comprising silver halide grains spectrally sensitized with a sensitizing dye represented by: (10) The combination according to claim (2), wherein the rear screen is made of an ultraviolet-emitting phosphor having more than 80% of its emission spectrum at 410 nm or more and whose emission maximum is in the wavelength range of 300 to 360 nm. body. (11) The rear screen is made of a barium sulfate phosphor activated with lead or lanthanum, a barium fluorohalide phosphor, a barium silicate phosphor activated with lead, or an yttrium oxide phosphor activated with gadolinium. Claim (2) consisting of an ultraviolet emitting phosphor selected from the group consisting of a photon, a barium fluoride phosphor, and an alkali metal activated rare earth niobate or tantalate phosphor. A combination of (12) The rear screen has the general formula (Y_1_-_2)_/(_3_x_-_1)/(_3
_y'Sr_x'Li_y)TaO_4 (wherein, X and Y are 10^-^5≦x≦1 and 10^-^4≦y≦
Claim (2) comprising an ultraviolet emitting phosphor corresponding to (a number that satisfies the condition of 0.1)
A combination of (13) The combination of claim (2), wherein the backside silver halide layer consists of chemically sensitized but not spectrally sensitized silver iodobromide grains. (14) (I) For silver halide radiography consisting of two independent front and back X-ray fluorescent screens and a support base and front and back silver halide emulsion layers coated on both sides of the support. i) the front screen is located adjacent to the front silver halide layer, and the back screen is located adjacent to the back silver halide layer; and i) the front screen is a first ii) the rear screen comprises a radiation-emitting phosphor, and the front silver halide layer comprises silver halide grains sensitive to the first radiation emitted by the front screen; and ii) the rear screen comprises a first radiation emitting phosphor. X-ray imaging of a combination of photosensitive elements comprising a radiation-emitting phosphor and said rear silver halide consisting of silver halide grains sensitive to said second radiation emitted by said rear screen. and (II) developing the silver halide radiographic element, the method comprising the steps of: a) the first radiation emitted by the front screen is directed to the rear screen; b) the front silver halide emulsion layer has a wavelength that differs by at least 50 nm from the second radiation emitted by the rear screen; and c) said rear silver halide emulsion layer is substantially insensitive to said first radiation emitted by said front screen; , the difference in the wavelength range of said first and second radiation, and the insensitivity of each silver halide layer to the radiation emitted by the opposite screen,
The method of recording radiographic images is such that cross-over exposure is reduced by at least 10% compared to a symmetrical combination of a pair of green light-emitting fluorescent screens and a double-coated green light-sensitized silver halide radiographic element. . (15) a) the front screen is comprised of a phosphor emitting non-actinic radiation, and the front silver halide layer is a halogen spectrally sensitized to the radiation emitted by the front screen; and b) the back screen is made of a phosphor that emits ultraviolet light, and the back silver halide layer is made of silver halide grains that are not spectrally sensitized. Radiographic recording method. (16) The radiation according to claim (14), wherein the front screen is made of a green light-emitting phosphor in which more than 80% of its emission spectrum is 480 nm or more and its emission maximum is in the wavelength range of 530 to 570 nm. Image recording method. (17) The front screen has the general formula (Ln_1_-_a_-_b'Tb_a'Tm_b)_
2O_2S (wherein Ln is at least one rare earth element selected from lanthanum, gadolinium, and ruthenium, and a and b are each 0.0005
≦a≦0.09 and 0≦b≦0.01), or the general formula (Y_1_-_c_-_a_-_b′Ln_c′Tb_
a'Tm_b)_2O_2Tb (wherein Ln is at least one rare earth element selected from lanthanum, gadolinium, and ruthenium, and a, b, and c are respectively 0.0005≦a≦0.09, 0≦ b≦0
．． 01 and 0.65≦c≦0.95) The radiation image recording method according to claim 14, comprising a green light emitting phosphor represented by: (18) The method of claim (14), wherein the front screen is comprised of a terbium-activated gadolinium or lanthanum oxysulfide phosphor having emission peaks substantially at 487 nm and 545 nm. (19) The radiation image recording method according to claim (14), wherein the front silver halide layer comprises silver halide grains spectrally sensitized with a spectral sensitizing dye of cyanine or merocyanine dye. (20) The front silver halide layer has a thickness of 530 to 570 nm.
consisting of silver halide grains spectrally sensitized with a spectral sensitizing dye so as to be sensitive to light in the wavelength range of m.
The radiation image recording method according to claim (14). (21) The front silver halide layer has a general formula ▲ mathematical formula, chemical formula, table, etc. , halogen atom, hydroxy group, alkoxy group,
represents an amino group, an acylamino group, an acyloxy group, an alkoxycarbonyl group, an alkyl group, an alkoxycarbonylamino group, or an aryl group, or each R
_6 and R_7 and R_8 and R_9 may be atoms necessary together to complete a benzene ring, and R
_1_1 and R_1_2 each represent an alkyl group, a hydroxyalkyl group, an acetoxyalkyl group, an alkoxyalkyl group, a carboxyl group-containing alkyl group, a sulfo group-containing alkyl group, a benzyl group, a phenethyl group, or a vinylmethyl group, and X^- is A radiation image recording method according to claim 14, comprising silver halide grains spectrally sensitized with a sensitizing dye represented by the following formula: an acid anion, and n represents 1 or 2. (22) The radiation according to claim (14), wherein the rear screen is made of an ultraviolet-emitting phosphor having more than 80% of its emission spectrum at 410 nm or more and whose emission maximum is in the wavelength range of 300 to 360 nm. Image recording method. (23) The rear screen may be a barium sulfate phosphor activated with lead or lanthanum, a barium fluorohalide phosphor, a barium silicate phosphor activated with lead, or a yttrium oxide phosphor activated with gadolinium. Claim (14) consisting of an ultraviolet emitting phosphor selected from the group consisting of a photon, a barium fluoride phosphor, and an alkali metal activated rare earth niobate or tantalate phosphor. radiographic recording method. (24) The rear screen has a general formula (Y_1_-_2_/_3_X_-_1/_3_y′S
r_y′Li_z)TaO_4 (where x and y are 1
Claim (14) consisting of an ultraviolet emitting phosphor corresponding to
) radiographic image recording method. (25) The radiation image recording method according to claim (14), wherein the back surface silver halide layer is comprised of silver iodobromide grains that have been chemically sensitized but not spectrally sensitized. (26) A silver halide radiographic element comprising a support base and front and back silver halide emulsion layers coated on both sides of the support, wherein the front silver halide emulsion layer has wavelengths of non-actinic radiation. 1. A silver halide radiographic element as described above, characterized in that the backside silver halide emulsion layer comprises silver halide grains that are sensitive to ultraviolet light or blue. (27) A silver halide radiographic element consisting of two independent front and back X-ray fluorescent screens and a support base and front and back silver halide emulsion layers coated on both sides of the support. the front screen is positioned adjacent to the front silver halide layer, and the back screen is positioned adjacent to the back silver halide layer, and i) the front screen is a first radiation-emitting layer. a phosphor, and said front silver halide layer comprises silver halide grains sensitive to said first radiation emitted by said front screen, and ii) said back screen comprises a first radiation emitting layer. A combination of photosensitive elements for use in radiography, comprising a phosphor, and said rear silver halide comprising silver halide grains sensitive to said second radiation emitted by said rear screen. a) the first radiation emitted by the front screen has a wavelength that differs by at least 50 nm from the second radiation emitted by the back screen, and b) the front halogen c) the silver halide emulsion layer is substantially insensitive to the second radiation emitted by the back screen; and c) the back silver halide emulsion layer is emitted by the front screen. characterized in that it is substantially insensitive to said first radiation, and thus to the difference in the wavelength range of said first and second radiation, and to the radiation emitted by the opposite screen. The photoinsensitivity of each silver halide layer is
The combination is such that the cross-over exposure is reduced by at least 10% compared to a symmetrical combination of a pair of green light-emitting fluorescent screens and a dual-coated green light-sensitized silver halide radiographic element. (28) A silver halide radiographic element consisting of two independent front and back X-ray fluorescent screens and a support base and front and back silver halide emulsion layers coated on both sides of the support. the front screen is positioned adjacent to the front silver halide layer, and the back screen is positioned adjacent to the back silver halide layer, and i) the front screen is a first radiation-emitting layer. a phosphor, and said front silver halide layer comprises silver halide grains sensitive to said first radiation emitted by said front screen, and ii) said back screen comprises a first radiation emitting layer. a combination of photosensitive elements for use in radiography, comprising a phosphor, and said rear silver halide comprising silver halide grains sensitized to said second radiation emitted by said rear screen. a) the first radiation emitted by the front screen is in the first wavelength range of the electromagnetic spectrum, and the second radiation emitted by the back screen is in the second wavelength range of the electromagnetic spectrum; b) said front silver halide emulsion layer is substantially insensitive to said second radiation emitted by said back screen, and c) said back silver halide emulsion layer is substantially insensitive to the first radiation emitted by the front screen.