JP2001166408A - Photosensitive silver halide photographic film material and radiographic intensifying screen-film combination - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a desired blue-black image tone even when high covering power is measured with respect to a processed film giving a diagnostic image given by a double coated radiographic material coated with a photosensitive layer having thin flat platy grains. SOLUTION: The photosensitive silver halide photographic film material includes a transparent substrate and at least one photosensitive emulsion layer on one side or both sides of the substrate. The photosensitive emulsion layer has silver bromide-rich spectrally and chemically sensitized flat platy silver halide grains each having two flat parallel 111} crystal faces. The grains occupy at least 50% of the total projected surface area of the parallel crystal faces in the emulsion and have an average ratio of at least 2:1, 0.05-0.15 μm grain thickness, >=1×10-4 mol specified region directive compound per mol of coated silver and one or more J cohesive spectral sensitizing dyes. The molar ratio between the region directive compound and the sensitizing dye is at least 1:6 with respect to >50% grain coating weight of the 111} flat platy grains.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a radiographic photosensitive silver halide photographic film material having thin tabular {111} hexagonal grains rich in silver bromide, said film material and two radiographic sensitized luminescent phosphorescent layers. And a method for forming a black-and-white diagnostic image after exposure of said screen / film combination with X-rays.

[0002]

BACKGROUND OF THE INVENTION Since the early eighties, the practical use of light-sensitive silver halide grains or crystals has been a common knowledge for anyone skilled in the art of photography. {111}
Production of tabular silver halide grains, sensitivity increase by spectral and chemical sensitization, and photosensitive silver halide photographic materials,
In particular, 0.20 as described in US-A 4,414,304 and its corresponding patents in Japan and European countries.
From the basic patent of Eastman Kodak based on them for coating in precured double coated radiographic materials showing improved covering power for tabular grains having a thickness of less than μm, encountered by using such grains Problems have been found to be associated with image tone and developability as described in US-A 5,595,864.

[0003] In radiographic applications, the film material is coated with a relatively high amount of silver to provide suitable sensitometry, even if a low radiation dose is always applied to the patient as desired. The use of {111} tabular silver halide grains allows for lower silver coverage if compared to grains having a more spherical shape, for example, as applied before the actual application of said tabular grains. Within {111} tabular grains, those with high "tabularity" (defined as the ratio of aspect ratio to grain thickness) are much more favorable for low coverage silver halide, but have high tabularity The need to provide acceptable image tones after development of such a material having a photosensitive silver halide layer containing the tabular grains is rather severe: of {111} tabular grains previously coated on radiographic film material. Although the thickness reduction provided high covering power, it was clearly associated with the development of a diagnostic image having a reddish-brown image tone that was unacceptable to radiologists as an image tone after processing of such materials, and image quality Are closely related to one another in the special context of examination of diagnostic images.

The steps well known in the art to obtain a change in image tone from reddish brown to the desired bluish black of developed silver have heretofore been unsatisfactory. Absent. Coating a light-sensitive emulsion layer on a blue base as in US-A 5,800,976 increases the minimum density. It is a phenomenon recognized by radiologists as an undesirable increase in fog density.
The incorporation of such dyes or dye precursors into the other layers of the film material, which directly or indirectly gives a blue color (by processing and oxidative coupling reactions), is described, for example, in US Pat.
716768 and 581229 and EP-A 084
4520, and JP-A 10-274824, respectively, which produce the same problems as described above, and in the worst case, with a blue dye which diffuses from the material onto the screen, in the rapid processing cycle desired today. Shows the fouling of the screen with residual color of the dye due to incomplete removal of the dye, and the problems associated with the storage properties of the material and the criticality of the development of image-developed blue tinted silver.

[0005] Another problem with ultrathin tabular grains relates to the need to provide vast amounts of suitable spectral sensitizers to achieve increased total specific surface area and desired sensitometric properties. The achievable speed is in addition to the possible changes in the exposure absorption spectrum that can be expected, as well as the absorption properties of the spectral sensitizer at the required high concentrations and also the grains coated with said enormous amounts of spectral sensitizer. Greatly depends on the development suppressing characteristics of In particular, the development-inhibiting properties (leading to desensitization phenomena) may burden the achievable sensitometric properties, including covering power and residual color after processing. In addition, the effect on the color-reducing properties of the processing by the use of image tones and large amounts of spectral sensitizers for their thin tabular grains is not known, especially with minimal replenishment to obtain the lowest possible amount of chemical waste. This can be a severe problem when rapid processing is required in reduced ecological treatment systems.

Last but not least, the reduction in silver halide coverage in silver halide photographic materials is double-sided coated photographic materials, especially those that are spectrally sensitive to irradiation in the blue to ultraviolet wavelength range. Reduced image quality due to the increased crossover percentage measured for those spectrally sensitized to the green wavelength range of the visible light spectrum, which is typically expected to exhibit lower image resolution Maybe not. Since the light absorption of the spectral sensitizer should not be reduced when lowering the silver halide coverage, the amount of spectral sensitizer should be increased, which is the case for tabular grains having high tabularity. It perfectly matches the conditions described above. In addition, the high amount of spectral sensitizer for such grains is closely related to the need for a suitable site-directing action of the sensitizer to provide optimal chemical sensitization without further loss processing.

[0007]

SUMMARY OF THE INVENTION Therefore, the first aspect of the present invention is as follows.
The purpose is when high covering power is measured for a processed film giving a diagnostic image given by a double-sided radiographic material coated with a photosensitive layer having thin tabular grains up to 0.15 μm thick. Even so, it is to meet the strict requirements for obtaining the desired blue-black image tone.

A second object of the present invention is to reduce the residual color of a diagnostic black-and-white image obtained after processing of a radiographic photosensitive silver halide film material containing a latent image of a subject to a minimum level.

A third object of the present invention is to provide favorable sensitometric properties of the film material, especially high speed.

It is a further object of the present invention to provide good image quality which is reflected at a low crossover percentage. Further objects will become apparent from the description below.

[0011]

SUMMARY OF THE INVENTION To achieve the objects of the present invention, there is provided a photosensitive silver halide photographic film material, said material comprising a transparent support and at least one photosensitive emulsion layer on one or both sides thereof. Wherein the photosensitive emulsion layer has two flat parallel {111} crystal faces, is rich in silver bromide, and further has silver iodide in an amount of less than 3 mol% based on silver, spectrally and Chemically sensitized tabular silver halide grains (i), wherein the grains account for at least 50% of the total projected surface area of the parallel crystallographic planes in the emulsion and further have an average aspect ratio of at least 2: 1 , Having a particle thickness of 0.05-0.15 μm), 1 × 10 ⁻⁴ mol per mol of silver coated
(Ii) a site-directing compound satisfying general formula (I.1) or (I.2) as described in the claims and detailed description of the invention in the above amounts.
And one or more J-aggregated spectral sensitizing dyes (iii),
The molar ratio between the site-directing compound and the J-aggregation spectral sensitizing dye is at least 1: 6 for the particle coverage of the {111} tabular grains exceeding 50%, and the site-directing compound has the formula (I) .1) or (I.2). Also disclosed is a radiographic screen / film combination comprising a photosensitive silver halide photographic film material in combination with a pair of supported or self-supported X-ray intensifying screens, wherein the screen is spectrally sensitized with the film material. It consists essentially of luminescent phosphor particles that emit light in a range of wavelengths.

Also disclosed is a method for forming a black-and-white image that provides a diagnostic image, the method including exposing the screen / film material to X-rays passing through a subject, developing, fixing,
Processing the film material by rinsing and drying.

[0013]

Detailed Description of the Invention In order to achieve the full benefits of the present invention for a radiographic film material having thin {111} tabular silver halide grains rich in silver bromide as further described herein, The high amount of the site-directed azacyanine compound satisfying the general formula (I) described in
Mol of coated silver halide as claimed
Per 1 × 10 -4 ^mol or more) is required in the light-sensitive emulsion layer of the double-side coated or double-sided coated radiographic film material with one or more J-aggregating spectral sensitizing dyes, the said site-directed compound J-aggregating spectral sensitizing dyes It was unexpectedly found that the molar ratio amount between should be at least 1: 6 for particle coverage greater than 50%.

Certain particularly preferred azacyanine dyes for use in the emulsion coated on the photosensitive layer of the material of the present invention are those of the following formula (I.1) or (I.2).

Embedded imageWherein the substituent R¹-R⁴Are each independently hydrogen,
Substituted or substituted) alkyl, (unsubstituted or substituted) aryl or
Represents an (unsubstituted or substituted) aralkyl group; ¹And R
²And / or R³And R⁴Is (substituted or unsubstituted) benzo
May form a ring, which, if substituted,¹-R⁴
Having the same or different substituents as R;
Alkyl), (unsubstituted or substituted) aryl or (unsubstituted)
R ′ represents hydrogen, (unsubstituted or substituted) aralkyl group;
Substituted or substituted) alkyl, (unsubstituted or substituted) aryl or
Represents an (unsubstituted or substituted) aralkyl group;
The anion exists as a charge compensating ion.

More preferably, each of R and R 'is independent
(CH₂)_nH or (CH₂) _nOH (n is 1 to 4
), (CH₂)_m(SO₃ ⁻)
Or (CH₂)_mO (SO₃ ⁻) (M has a value of 2 to 4)
), (CH₂)₂CH (Y) SO
₃ ⁻(Y is CH₃-, -Cl or -OH), (C
H₂)_mN (R) SO₃ ⁻Or (CH₂)_mN (R ')
SO₃ ⁻, (CH₂)_n(COO⁻) Or (CH₂)_n
(COOH), (CH₂)_sSO₂ ⁻(CH₂)_tH
(S equals 2 or 3 and t equals 1 or 2),
(CH₂)_x-Phen-W (W is -COO⁻Or SO
₃ ⁻Represents a substituted or unsubstituted phenyl.
And x is equal to 1, 2, 3 or 4), (CH₂)_nC
ONHSO₂R or (CH₂)_nCONHSO₂R '
(Where R 'is hydrogen or a latent soluble group as described above, for example,
For example (CH₂)_{m '}-(C = O) -O-CH₂− (C =
O) -CH₃(M 'is an integer having a value of 1 to 5
)).

Preferred charge compensating cations for obtaining a neutral azacyanine structure are Li ⁺ , Na ⁺ , K ⁺ , HN ⁺
A Et ₃ (Et represents ethyl), preferably charge compensation anions ^{Cl -, Br -, I -} , - OTos, - O
_{^{Mes, CF 3 SO 3 - (}} - OTos represents ^tosylate, - OMes represents mesylate) it is.

Particularly preferred examples of azacyanine dyes are given by the following formulas (I.3) to (I.13):

Embedded image

Embedded image

Embedded image

The silver halide photographic film material of the present invention comprises a transparent film support having first and second major surfaces, wherein the first and second major surfaces are on one or both sides of said major surface of the support. Overcoated with at least one photosensitive layer overcoated with a protective stress-resistant layer, said photosensitive layer being rich in silver bromide, silver iodide being present in an amount of less than 3 mol%, based on silver; Photosensitive emulsions having {111} tabular grains having an average grain thickness of from 0.05 to 0.15 μm comprise at least 50%, preferably at least 70%, more preferably at least 90% of the total projected surface area of all grains. And in addition to one or more J-aggregated spectral sensitizing dyes as an essential feature of the invention, are described herein in high amounts of 1 × 10 ⁻⁴ mol or more per mol of coated silver halide. General like It has a site-directed azacyanine compound satisfying (I.1) or (I.2), and the molar ratio between the site-directed compound and the J-aggregation spectral sensitizing dye is at least for a particle coverage of more than 50%. 1: 6, and the ratio is more preferably from 1: 3 to 1:
It is one.

The preparation of spectrally and chemically sensitized tabular grains which may be applied to emulsion grains coated in the photosensitive layer of a radiographic material according to the present invention is disclosed in US Pat.
A4439520, in which it has been established that spectral sensitization is performed before chemical sensitization so that the spectral sensitizer acts as a site directing agent for the sensitivity spots generated during chemical sensitization. A broad overview of spectral sensitization is provided in Research Disclosure No. 389057,
p.591-639 (1996), especially in Chapter V. Further useful information about additives that may be used to make the emulsions coated on the materials according to the invention is found in Research Disclosure No. 389057, p. 591-639 (1996).
For antifoggants and stabilizers, Chapter VIII for additives that alter coating physical properties, and Chapter VIII for layer layout.
XI and the support is described in Chapter XV.

The {111} tabular silver halide emulsion grains present in the light-sensitive emulsion layers of the material according to the present invention are especially sensitive to sharpness (low crossover percentage), contrast (which depends on the density range in which image details can be recognized). Dependent contrast "), speed and density range, depending on the conditions as stated by the physician examining the radiological image, preferably prior to chemical sensitization, from blue to near-ultraviolet wavelengths. Spectrally sensitized to the green and / or green wavelength range.

In a particular example of the present invention, the double-coated film material is spectrally sensitized to radiation in the green wavelength range, but the J-aggregate green sensitizer having the high amount of azacyanine dyes described in the text of the present invention. Substrates primed with {111} hexagonal tabular grains, rich in silver bromide and having an amount of silver iodide of less than 3 mol% based on silver, which have been treated prior to adsorption of the dyes Included in the overlying photosensitive emulsion layer.

The radiographic film material according to the invention thus treated in a high amount of at least 10 ^-4 mol per mol silver of the site-directed azacyanine dye according to general formula (I) satisfies general formula (II) and 555n
It is spectrally sensitized to irradiation in the green wavelength range from 500 to 555 nm by the further presence of at least one spectral sensitizing (orthochromatic) dye having a maximum absorption in the wavelength range m.

Embedded imageIn the formula, Z and Z 'each independently represent a nitrogen or oxygen atom
And if Z is a nitrogen atom then Z is R⁸Replaced by
And if Z 'is a nitrogen atom, Z' is R⁹R;⁵, R
⁶And R⁸And R⁹Is independently substituted or unsubstituted
Represents alkyl, R⁷Is hydrogen, substituted or unsubstituted alkyl
Or T represents a substituted or unsubstituted aryl, and T and T ′ represent
Each independently hydrogen, substituted or unsubstituted alkyl, substituted or
Represents an unsubstituted aryl or a substituted or unsubstituted heterocyclic group
Well; (X⁻)_pCompensates for the positive charge present on the dye
Represents a negatively charged atom or group of atoms for
(M⁺) _qIs to compensate for the negative charge present on the dye
Represents a positively charged atom or group of atoms, p and q represent
The integers for obtaining independently electrically neutral compounds
Represent.

More preferred examples of the material according to the invention
Preferred silver bromoiodide or silver bromochloroiodide {111}
J-aggregated cyanine color adsorbed on the particle surface of diamond-like hexagonal particles
The element corresponds to the general formula (II), wherein R⁷Is -C₂H
₅And Z and Z ′ both represent an oxygen atom;⁵Passing
And R⁶At least one is a -sulfoalkyl group, preferably of the formula-(CH₂)_nS
O₃ ⁻(N is equal to 2, 3 or 4),-(CH₂)₂
-CH (CH₃) -SO₃ ⁻And -CH₂-CHY'-
CH₂-SO₃ ⁻(Y ′ represents —OH or —Cl)
A sulfatoalkyl group, preferably of the formula-(CH₂)
_nOSO₃ ⁻(N is equal to 2, 3 or 4)
An acylsulfonamide group, preferably of the formula-(C
H₂)_n-C (O) -N (R¹⁰) -SO₂− (C
H₂)_mH (n is equal to 1, 2, or 3, m is 1, 2, 2,
3, etc.),-(CH₂)_r-SO₂−N (R
¹⁰) -SO₂− (CH₂)_sH (r is 2, 3 or 4
Equals, s equals 1, 2, 3, etc.),-(CH ₂)
_v-SO₂−N (R¹⁰) -C (O)-(CH₂)_wH
(V is equal to 2,3 or 4, w is equal to 1,2,3 etc.
A carboxyalkyl group, preferably of the formula (CH₂)_x
COOH or (CH₂)_xCOO⁻(X is 1, 2, 3
R)¹⁰Represents H or alkyl
T and T ′ are each independently hydrogen, 5-phenyl
5-Cl, 5-OCH₃And 5-CH₃Represents

In a further preferred example, the J-aggregated cyanine dye corresponds to the general formula (II), wherein R ¹¹ is hydrogen, Z is a nitrogen atom, T is hydrogen, 5-phenyl,
5-Cl, represent 5-OCH ₃ or 5-CH _3, T 'is _{5,6- (Cl) 2; 5-} CN-6-Cl; 5-CF 3
-6-Cl; 5-Cl; 5-CN, 5-CF 3, 5-C
_{HF 2, 5-SO 2 CH} 3 or ^{_5-SO 2 R} 12 ^(R
12 represents a fluorine-substituted or fluorine-substituted alkyl group), 5-COOR ¹³ and ^{_{5-SO 2 -N (R x}} )
(R ^y ) or 5-CO-N (R ^x ) (R ^y ) (R ^x and R ^y each independently represent a substituted or unsubstituted alkyl group, which form an N atom and a ring to which they are attached. May be formed).

In formula (II), even more preferably, Z
And Z 'each represent oxygen and each of T and T'
Which represents Cl or T represents Cl, T 'is phenyl
Or vice versa, and R⁵And R⁶Is the formula-
(CH₂)_nSO₃ ⁻(N is equal to 2, 3 or 4),
− (CH₂)₂-CH (CH₃) -SO₃ ⁻And -CH
₂-CHY-CH₂-SO₃ ⁻(Y is -OH or -Cl
Represents all combinations), corresponding to the formula given above
R⁵Is of the formula-(CH₂)_jH (j is 1, 2, 3 or 4
Equal), -CH₂-Phen-SO₃ ⁻, -CH₂−
Phen-COOH,-(CH₂ )_k-Phen-C
OOH (k is equal to 1, 2 or 3),-(CH₂ )
_l-COOH (l equals 1, 2 or 3 etc.)
R⁶Is combined with

In a particularly preferred example, the J-aggregated spectral sensitizing dye is 5,5'-dichloro-3,3'-bis (S
O ₃ -R)-9-ethyl - a benz oxacarbocyanine (R is n- propylene or n- butylene), especially anhydro-5,5'-dichloro-3,3'-
Bis (n-sulfobutyl) -9-ethyloxacarbocyanine hydroxide or anhydro-5,5'-dichloro-3,3'-bis (n-sulfopropyl) -9-ethyloxa-carbocyanine hydroxide. JP-A 06/035104; 06/035101;
06/035102; 62/191847; 63/24
9839; 01/325536; 03/200246;
Green light absorption spectral sensitizers according to the formula given in US-A 4,777,125 and DE 3,819,241 may be used. The correct choice of the sensitizers or combinations thereof is always linked to the goal of obtaining the highest possible photographic speed while reducing dye stain after processing.

To characterize the {111} hexagonal tabular grains with quantitative parameters, the average particle volume was determined after applying the electrochemical reduction technique, and was calculated after measurement for each individual particle of that volume. The electrical signal thus obtained is related to the silver halide grain volume after reduction to total metallic silver at the cathode of the electrochemical cell. The percentage of the total projected area of all tabular grains to the total projected area of all grains present in the emulsion is calculated from electron micrographs.

The average grain diameter and thickness of the tabular grains are calculated after the determination of the individual grain thickness and diameter, calculated as the equivalent circular diameter of the hexagonal plane from shadow or scanning electron micrographs. The aspect ratio is determined from the average (equivalent circle) diameter to thickness ratio for each individual tabular grain, allowing the average aspect ratio of the tabular grains in the emulsion distribution to be further calculated.

Such an average crystal diameter for the emulsion crystals present in the photosensitive layer of the material according to the invention is between 0.3 and 3.
0 μm, the particles are two flat, parallel ｛11
It has a 1｝ crystal plane and occupies at least 50%, more preferably at least 70%, even more preferably 90% or more of the total projected surface area of the parallel crystal planes in the emulsion of the grains.

(Equivalent circle) for each individual tabular grain
The aspect ratio is determined from the average ratio of diameter to thickness, and the average aspect ratio of the tabular grains in the emulsion distribution of the material according to the invention can be further calculated: said aspect ratio is preferably 5 or more, especially 5 : 1 to 50:
1, more preferably 5: 1 to 20: 1.

It is essential that the amount of iodide be limited, ie less than 3 mol% based on silver, to be advantageous not only for image tones as described for the purposes of the present invention, but also for developability. It is a characteristic. More preferably, the iodide is less than 3 mol%, preferably less than 1 mol%, more preferably 0.05 mol% to 0.5 mol% based on silver.
%, And most preferably to obtain an average amount of iodide throughout the grain volume of 0.1 mol% ～0.4Mol% Rights
It exists as silver iodide on the surface of the tabular grains .

The double-sided radiographic film material according to the invention most preferably comprises a photosensitive layer on both sides of the film support, wherein the thin {111} tabular silver halide grains rich in silver bromide comprise from 0.1 mol% to It contains a limited amount of 0.4 mol% of silver iodide. # 11 in photosensitive emulsion
It is preferred that the 1｝ tabular grain population be more homogeneous. That is, it preferably has a variation count of 0.40 or less, more preferably 0.10 to 0.30, based on the equivalent circular diameter calculated for the individual {111} tabular grains.

The method for producing {111} tabular grain emulsions rich in silver bromide is described in Research Disclosure No. 389057, p.591-639.
(1996), especially in Chapter I. A very useful method is described in EP-A 0843208. The {111} tabular hexagonal rich in silver bromide is preferably comprised of silver bromoiodide or silver bromochloroiodide (having less than 10 mol% silver chloride based on silver). Iodide ions present on the surface of all {111} tabular hexagonal grains are provided in a production process by addition of an inorganic iodide salt such as potassium iodide. More preferred is to provide a slow release of iodide in the reaction vessel, up to 3 mol%, preferably up to 1 mol%, most preferably up to 0.1 mol%, based on silver over the total grain volume.
% To 0.4 mol% of silver iodide to give a low silver iodide concentration. Addition of iodide with an organic agent that releases iodide ions is for example E
P-A 0561415, 0563701, 05637
08 and 0651284 and US-A 5,482,826
And 5,736,312. Alternatively, iodide ions can be released from iodate as described in US-A 5,736,312. Release of iodide in the presence of a compound that modulates iodide release rate is U
It can be applied as described in SA 5807663.

In another preferred embodiment, the addition of iodide to silver bromide-rich emulsion grains reduces the finely preformed grains of silver iodide, whether or not they contain small amounts of bromide and / or chloride. It is performed by adding. The particles are 10
It has a particle diameter of 0 nm or less, more preferably 50 nm or less. Such fine grains are so-called "Lipman" emulsions. The addition of iodide utilized from such fine grains rich in silver iodide is described in JP-A04-251241 and 08-02.
9904 and EP-A 0666232 and 06588
05 describes the preparation of {111} tabular grains, wherein the outermost phase rich in silver iodide is silver bromide-rich {111} tabular grains (optionally containing up to less than 10 mol% silver chloride). Is added to 1m in particle
The addition of the fine AgI-Lipmann emulsion to the surface of the silver halide crystal to obtain a total iodide content of less than ol% may advantageously be carried out as disclosed in EP-A 0 475 191, where it is excellent. A high speed / fogging ratio and high covering power are achieved.

The preparation of {111} tabular grain emulsions is carried out in the presence of gelatin or colloidal silica sol as a binder to provide colloidal stability during all the manufacturing steps. In one example, the precipitation of tabular silver halide crystals according to the present invention is performed in the presence of a protective hydrophilic colloid (eg, conventional lime-treated or acid-treated gelatin), but with oxidized gelatin (see, eg, EP-A 0843208) or Synthetic peptizers may be used. The production of such modified gelatin types is described, for example, in "The Science and Technology of Gelati
n ”, edited by AG Ward and A. Courts, Academic Press 197
It is described on page 7, 295 and the next page. Gelatin is Bull.
Enzyme-treated gelatin as described in Soc. Sci. Phot. Japan, No. 16, page 30 (1966). It is common practice to establish a gelatin concentration of about 0.05% to 5.0% by weight in the dispersing medium before and during the formation of silver halide grains.

In another example, the tabular silver halide grains used in the emulsions according to the invention use a colloidal silica sol as protective colloid in the presence of an onium compound, preferably a phosphonium compound, as described in EP-A 0 677 773. Precipitation in the absence of gelatin.

To control grain size, other grain growth inhibitors or accelerators may be used during precipitation in addition to the dye (eg, a spectral sensitizing dye) or a crystal habit modifier, and silver and halide salt solutions Flow rate and / or concentration, temperature, pA
g, physical aging time, etc. may be changed together. Silver halide solvents such as ammonia, thioether compounds, thiazolidine-2-thione, tetrasubstituted thioureas, potassium or ammonium rhodanides and amine compounds may be present in the grain precipitate to further adjust the average grain size.

At the end of the precipitation, the emulsion can be rendered free of excess soluble inorganic salts by conventional washing techniques (eg, one or more washing and redispersion steps after aggregation with ammonium sulfate or polystyrene sulfonate). Another well-known washing technique is ultrafiltration. Ultimately, extra gelatin can be added to the emulsion to obtain an optimized gelatin to silver ratio with respect to the coating conditions and / or to establish the required thickness of the coated emulsion layer. A gelatin to silver halide weight ratio of preferably 0.3 to 1.0 is then obtained.

The {111} tabular silver halide emulsion grains present in the photosensitive emulsion layer of the material according to the present invention, in addition to the spectral sensitization, are at least a preferred combination of an unstable sulfur compound and a gold compound, more preferably Obviously, it has been chemically sensitized with compounds that provide sulfur, selenium or tellurium and gold. Chemical sensitization of {111} tabular grain emulsions rich in silver bromide is described in Research Disclosure N
o.389057, p.591-639 (1996), especially in Chapter IV. A very useful method related to this is EP
-A 0443453, 045469, 054110
4 and US-A 5,112,733 and 5,654,134. A useful unstable selenium compound is EP-A
0813363, 0889354 and 0895121
Is disclosed. The unstable selenium compounds are generally applied in combination with sulfur and gold, and the unstable tellurium compounds are applied as disclosed in EP Application No. 99202439 (filed July 23, 1999).

It is generally coated from an emulsion-coated material having tabular grains, in particular an emulsion having such thin {111} hexagonal tabular grains coated with low amounts of silver without loss of covering power in the material. Especially preferred for the material according to the invention, the total amount of coated silver halide in said film material, expressed as equivalents of silver nitrate, is less than 7 g / m ² . In the film material according to the invention, the total amount of coated silver halide in said film, expressed as the equivalent of silver nitrate, is more preferably 3.
In the range of 0~6.0g / ^{m 2.}

These advantages are notable from an economic point of view (lower amounts of silver used) and an ecological point of view (lower amount of drug during processing and subsequent need for lower silver recovery).

A radiographic film material (referred to as "one-sided" material) coated on only one side of the support, suitable for use in radiographic applications such as mammography, is a thin hexagonal material as described above. Obviously, a photosensitive emulsion layer having crystalline {111} tabular grains can also be provided. Such materials have the advantage of better image resolution. Because the incident light generated by the luminescent phosphor enters from only one side of the film support, a pair of screens emitting light from each luminescent phosphor cause a pair of screens to emit light from both sides of the support. This is because there is no crossover as in the case of a double-sided coated film having an exposed transparent film support.

The double coated film material of the present invention is coated with a light sensitive emulsion layer having thin hexagonal {111} tabular grains that are spectrally and chemically sensitized after conversion of the x-rays passing through the patient. The film is illuminated by light emitted image-wise by an X-ray intensifying screen positioned as a sandwich on both sides of the film.

A diagnostic silver image consistent with the X-ray image is obtained after processing of the film material according to the invention. For use in general medical radiography (projection radiography), the X-ray film material is coated on both sides with at least one silver halide emulsion layer, and additionally with at least one protective stress-resistant layer and optionally EP-A, for example. 06444454 and 06444
56, comprising a transparent film support overcoated with an after layer as disclosed in US Pat. Furthermore, in addition to the components normally added to the protective stress-resistant layer (see Examples), a mercaptotetrazole compound, preferably a substituted 1-phenyl-5-mercaptotetrazole compound, is added in an amount of at least 0 per mol of silver halide. More preferably, it is added in an exceptionally large amount of 0.5 mmol and 10 mmol or less. The presence of such a compound in the protective stress-resistant layer indicates that the "cooler" black-blue image is at least the same,
It has been established that the image tones are further improved in terms of what is gained for a further increased covering power.

During X-ray irradiation, the film is placed in a cassette between two X-ray intensifying screens. Both of them are in intimate contact with the corresponding photosensitive side and thus the film /
Form a screen system.

In one embodiment according to the present invention, a double-sided coated film material in intimate or sandwiched between a pair of supported or self-supported X-ray intensifying screens characterized by the following (i) and (ii): There is provided a radiographic screen / film combination or system comprising: (i) a supported or self-supported X-ray intensifying screen is blue / ultraviolet and / or green, such as a terbium-doped gadolinium oxysulfide phosphor Consisting essentially of luminescent phosphor particles emitting at least 50%, more preferably at least 80% of the radiation emitted in the wavelength range, especially the green wavelength range of 500 nm to 550 nm; (ii) said film material according to the invention Is a thin hexagonal crystal rich in said silver bromide, which has been spectrally sensitized to irradiation in a preferred wavelength range. One or more {111} tabular silver halide emulsions, as described above, containing 111 tabular grains are included in the photosensitive layer (the preferred wavelength range is at least one J-aggregation (green) spectrum according to general formula (II)). 500-550 nm depending on the presence of the sensitizer).

In the present invention, the general formulas (I.1) and (I.1) are particularly relevant for the purpose of obtaining reduced image stains in addition to excellent image tones, said reduced image stains providing essential advantages thereto. The azacyanine dye according to paragraph (2) should be used in large amounts as described above during the preparation of {111} tabular grain emulsions. Not only does the presence of the dye have a site-directing function, but it also allows for the addition of a lower amount of the J-aggregate spectral sensitizer according to general formula (II) without loss of speed, thereby improving processing. This is because it gives bleaching. Suitable J-aggregated spectral sensitizers for spectrally sensitized emulsions in the materials of the present invention are described in "The Cyanine Dyes and Rel" by FM Hamer.
ated Compounds ", 1964, John Wiley & Sons, while others are described in Research Disclosure Item 22.
534 and the recent review in EP-A 0 575 285, from which dyes which form a J-aggregate on a flat surface of preferred silver bromoiodide or silver bromochloroiodide are particularly useful.

According to the present invention, in a particular example, a radiographic screen / film combination comprising a photosensitive silver halide photographic film material as described above in combination with a supported or self-supported X-ray intensifying screen, Supported or self-supported X-ray intensifying screen of 540-555 nm
A radiographic screen / film combination is provided which consists essentially of luminescent phosphor particles emitting green light radiation in the wavelength range of

In addition to the spectral sensitizing dyes, other dyes that have no spectral sensitizing activity by themselves, or certain other compounds that do not substantially absorb visible radiation, may be incorporated into the emulsion with the spectral sensitizer. Can be added in order to give a supersensitizing effect. Suitable supersensitizers are, for example, heterocyclic mercapto compounds containing at least one electronegative substituent as described in US-A 3,457,078, for example US-A 2
Nitrogen-containing heterocyclic ring-substituted aminostilbene compounds as described in 933390 and 3635721, for example aromatic organic acid / formaldehyde condensed compounds and cadmium salts and azaindene compounds as described in US-A 3,743,510.

At least one non-spectral sensitizing dye may be used in combination with one or more non-photosensitive layers, such as an antihalation undercoat layer, between the subbing layer and the photosensitive emulsion layer to provide good adhesion between the support and adjacent layers. It can be added to the hydrophilic layer or to the emulsion layer. The presence of an adaptive amount of such dyes is recommended not only to adjust the sensitivity of the different emulsion layers and the resulting contrast required, but also to reduce the scattering of exposure radiation and thus enhance sharpness. Preferred dyes are those that are not easily removed from the photographic material during wet processing to leave no residual color. When the dyes are added to the emulsion side, they are preferably non-diffusing during the coating of the hydrophilic layer.
Examples of such dyes include, but are not limited to, for example, US-A 3
560214; 3647460; 4288534; 43
11787 and 4857446. These dyes are less than 10 μm, more preferably 1 μm.
m may be added to the coating solution as a solid particle dispersion of a water-insoluble dye having an average particle diameter of less than 0.1 μm. Examples of such dyes are EP-A
0384633; 0351593; 0586748; 0
587230 and 0656401, EP-A 0323
729; 0274723 and 0276566, and US
-A 4900653; 490465; 494965
4: 4940654; 4948717; 498861
1: 4803150 and 5343449. The dyes can also be added in the form of solid silica particle dispersions as disclosed in EP-A 0 569 074. Yet another technique applied to obtain ultrafine dye dispersions consists in acidifying the slightly alkaline coating composition "in situ" just prior to coating on the support layer.
A recent study of dispersion methods useful in this application is EP-A 0756.
201.

The silver halide emulsions used in the light-sensitive layer of the material according to the present invention contain compounds which stabilize photographic properties or prevent the formation of high minimum densities during the manufacture or storage of the photographic material or during its photographic processing. It may further include. Many known compounds can be added to a silver halide emulsion as fog inhibitors or stabilizers. Preferred examples are heterocyclic nitrogen-containing compounds such as benzothiazolium salts, nitroimidazole, nitrobenzimidazole, chlorobenzimidazole, bromobenzimidazole, mercaptothiazole, mercaptobenzothiazole, mercaptobenzimidazole, mercaptothiadiazole, aminotriazole, Benzotriazole (preferably 5-
Methyl-benzotriazole), nitrobenzotriazole, mercaptotetrazole, especially 1-phenyl-5
-Mercapto-tetrazole, mercaptopyrimidine,
Mercaptotriazine, benzothiazoline-2-thione, oxazoline-thione, triazaindene, tetraazaindene and pentaazaindene, especially by Birr, Z.
Wiss. Phot. 47 (1952), pages 2-58, GB-A 1203775 and GB-A 12
09146, JP-B77 / 031738, and GB-
Triazolopyrimidines, such as those described in US Pat. No. 1,500,278, and 7-hydroxy-s-triazolo- [1,5-
a] -pyrimidine and other compounds such as benzenethiosulfonic acid, benzenethiosulfinic acid and benzenethiosulfonic acid amide.

Other compounds that can be used as fog-inhibiting compounds are described in Research Disclosure No. 17643 (1978), Chapter
Described in VI. These fogging inhibitors or stabilizers can be added to the silver halide emulsion before, during or after ripening, and mixtures of two or more of these compounds can be used.

Particularly when gelatin is used as the binder, the binder of the layer may be a suitable hardener, for example of the epoxide type, of the ethyleneimine type, of the vinylsulfone type (eg of 1,3-vinylsulfonyl- 2-propanol or di (vinylsulfonyl) -methane, vinylsulfonyl ether compound, vinylsulfonyl compound having a soluble group, chromium salt (for example, chromium acetate and chromium alum), aldehyde (for example, formaldehyde, glyoxal, and glutaraldehyde), N -Methylol compounds (for example, dimethylolurea and methyloldimethylhydantoin), dioxane derivatives (for example, 2,3-dihydroxy-dioxane), active vinyl compounds (for example, 1,3,5-triacryloyl-hexahydro-s-triazine) It can be pre-cured with active halogen compounds (e.g., 2,4-dichloro-6-hydroxy -s- triazine), and mucohalogenic acids (e.g., mucochloric acid and Mukofenokishi chlorate). These curing agents can be used alone or in combination. Binders can also be hardened with fast-acting hardeners such as carbamoylpyridinium salts as disclosed in US Pat. No. 4,063,952 and with onium compounds as disclosed in EP-A 0408143.

The photographic material according to the present invention may further comprise various types of surfactants in the light-sensitive emulsion layer or in at least one other hydrophilic colloid layer. Suitable surfactants are saponins, alkylene oxides such as polyethylene glycol, polyethylene glycol / polypropylene glycol condensation compounds, polyethylene glycol alkyl ethers or polyethylene glycol alkyl aryl ethers, polyethylene glycol esters, polyethylene glycol sorbitan esters, polyalkylene glycol alkylamines or alkyls. Nonionic agents such as amides, silicone-polyethylene oxide adducts, glycidol derivatives, fatty acid esters of polyhydric alcohols and alkyl esters of saccharides; anionic agents containing acidic groups such as carboxy, sulfo, phospho, sulfate or phosphate groups; Aminoalkyl sulfonic acid, amino alkyl sulfate or phosphate, Rukirubetain, and such amphoteric agents amine -N- oxides; and alkylamine salts, aliphatic, aromatic,
Or a cationic agent such as a heterocyclic quaternary ammonium salt, an aliphatic or heterocyclic ring-containing phosphonium or sulfonium salt. Such surfactants may be used for various purposes, for example as coating aids, as antistatic compounds, as compounds to improve film transport in automatic film handling equipment,
It can be used as a compound that facilitates dispersion emulsification, as a compound that prevents or reduces adhesion, and as a compound that improves photographic properties such as high contrast, sensitization, and accelerated development. Acceleration of development may be useful, especially when rapid processing conditions are important, and include various compounds, preferably, for example, US Pat. No. 3,038,805;
It can be achieved with the aid of polyoxyalkylene derivatives having a molecular weight of at least 400, such as those described in 038075 and 4292400. Particularly preferred development accelerators are DE 2360878, EP-A 0
Polyoxyethylene containing repeating thioether groups as described in 634688 and 0674215. A mixture of the same or different development accelerators may be added to at least one hydrophilic layer on the emulsion side. Hydrophilicity in or in a water-permeable relationship with the photosensitive silver halide emulsion layer by a suitable amount of dextran or a dextran derivative to improve the coverage of the formed silver image and to provide high abrasion resistance in wet conditions It is advantageous to partially replace the hydrophilic colloid binder, preferably gelatin, of the colloid layer.

The photographic material of the present invention may further contain various other additives such as compounds for improving the dimensional stability of the photographic material, UV absorbers, spacing agents, lubricants, plasticizers, antistatic agents and the like. Additives suitable for improving dimensional stability include, for example, water-soluble or poorly water-soluble synthetic polymers such as alkyl (meth) acrylates, alkoxy (meth) acrylates, glycidyl (meth) acrylates, (meth) acrylamides, vinyl esters Of acrylonitrile, olefin, and styrene, or of the above with acrylic acid, methacrylic acid, α-β-unsaturated dicarboxylic acid, hydroxyalkyl (meth) acrylate, sulfoalkyl (meth) acrylate, and styrene sulfonic acid Copolymer). Preferred U
V absorbers include, for example, aryl-substituted benzotriazole compounds as described in US-A 3,533,794, US-A.
4-thiazolidone compounds as described in A 3314794 and 3352681, benzophenone compounds as described in JP-A 2784/71, US-A 370
Cinnamic acid ester compounds as described in US Pat. Nos. 5,805 and 3,707,375; butadiene compounds as described in US Pat. No. 4,045,229 and benzoxazole compounds as described in US Pat.

Generally, the average particle size of the spacing agent is 0.1.
2 to 10 μm. Spacing agents can be soluble or insoluble in alkali. Alkali-insoluble spacing agents usually remain permanently in the photographic material, while alkali-soluble spacing agents are usually removed in an alkaline processing bath. Suitable spacing agents can be made, for example, from polymethyl methacrylate, from copolymers of acrylic acid and methyl methacrylate, and from hydroxypropyl methylcellulose hexahydrophthalate.
Another suitable spacing agent is US-A 4,614,708.
It is described in.

Compounds which can be used as plasticizers for the hydrophilic colloid layer are polyols or acetamides such as trimethylolpropane, pentanediol, butanediol, ethylene glycol and glycerin. Furthermore, the polymer latex is preferably mixed into the hydrophilic colloid layer for the purpose of improving pressure resistance,
For example, a homopolymer of an acrylic acid alkyl ester or a copolymer thereof and acrylic acid, a copolymer of styrene and butadiene, and a copolymer or a homopolymer of a monomer having an active methylene group.

The photographic materials according to the present invention may contain an antistatic layer to avoid electrostatic discharge during coating, processing and other handling of the material. Such an antistatic layer may be an outermost coating, such as a protective or after layer, or a layer of one or more antistatic agents or a coating applied directly to a film or other support and overcoated with a barrier or gelatin layer. You may. Antistatic compounds suitable for use in such layers are, for example, vanadium pentoxide sol, tin oxide sol or conductive polymers such as polyethylene oxide or polymer latex, or polyethylene as described, for example, in U.S. Pat. An antistatic agent that provides permanent conductivity, such as dioxythiophene.

During X-ray irradiation of the radiographic film material of the present invention, the film material (which is spectrally sensitized to green light, for example in a preferred embodiment by suitable spectral sensitization of the photosensitive emulsion grains) is treated with Emits green light due to the presence of a luminescent phosphor that emits green light
It is placed in a cassette with an X-ray intensifying screen. For chest radiographs the cassettes are the same or different,
Two X-ray intensifying screens are provided in close contact with the two X-ray intensifying screens. When two intensifying screens are used, using two identical screens (having the same radiation sensitivity), emitting the same radiation but speeding up, for example for different coating amounts of phosphor (coating thickness) The use of two different screens, or even two intensifying screens with different light emission, is not excluded. Combinations of intensifying screens sensitive to blue / UV radiation and screens sensitive to green light are not excluded, which are the desired properties for sensitometry (the desired sensitometric curve from a diagnostic point of view) and / or
Or it is advantageous to achieve image quality (granularity and / or image resolution, especially sharpness).

Special (e.g., blue or green) light emitting green light, such as very special applications using asymmetric screens and (non) symmetric double-coated films in screen / film combinations for use in the diagnostic imaging method according to the present invention. Intensifying or converting screens are commercially available X-ray generators that provide exposure to X-rays having a tube voltage of 20-40 kV (such as mammography) and 70-100 kV (such as chest radiograph). It is. It is always desirable to expose the patient to a low X-dose, if possible, so exposure to a low voltage source is not excluded, but rather recommended.

A preferred luminescent phosphor coated on an X-ray conversion screen used in a green light sensitive film / screen system is Gd ₂ O ₂ S: Tb,
It emits light in the wavelength range of 540-555 nm.
Said phosphors and their use in intensifying screens are described in the patent literature, for example US-A 3,872,309;
9; 4912333; 4925594; 499435
5; 50213327; 5107125 and 525901
6 and GB Patent 1489398, which are suitable for use in the film / screen system according to the present invention. Otherwise a blue / UV emitting screen is used on one side, said screen being 420
at least 50% of their emitted radiation in the wavelength range shorter than nm, more preferably at least 80%
% For blue / UV emitting luminescent phosphor particles, see US-A 4,256,563;
4378141; 4710637; 5112700; 5
173611 and 5432351; EP-A 0650
089; 0658613; PCT application WO 93/11
Special intensifying screens that emit ultraviolet-blue radiation can be used as disclosed in US Pat. No. 457 and WO 95/15514. Typical blue-UV emitting phosphors therein are PCT applications WO 93/1521 and 93/1.
Tantalate, US-A 5 as described in US Pat.
Hafnate and US- as described in US Pat.
WO 91/1357 doped with europium and co-doped with samarium as described in US Pat. Nos. 5,422,220 and 5,547,807 and US Pat. No. 5,629,125.
Representative examples for the well-known production of barium and strontium fluorohalides (fluorobromides) and luminescent phosphors as described in
US Pat. No. 5,077,145 and EP-Substituting WO ₄
A 0533234 is a mixture of tantalate and fluorohalide. Very useful phosphor particles are disclosed, for example, in EP-A-0 823 069, in which niobium-doped monoclinic M, yttrium tantalate phosphor particles and europium-doped barium fluorohalide phosphor particles constitute a screen. . Formula YTaO _4: Gd: monoclinic M is niobium and gadolinium doped by Nb, the phosphor particles with yttrium tantalate (MYT) phosphor are particularly useful.

The thickness of the phosphor layer therein depends on the amount of coated phosphor required to obtain the desired screen speed. The X-ray intensifying screen used in the film / screen system according to the invention can be self-supported or supported. The X-ray intensifying screen in the screen / film system according to the invention generally comprises a support (also referred to as a substrate), at least one layer comprising phosphor particles dispersed in a suitable binder and, in use, A protective coating is applied over the phosphor-containing layer to protect the layer. In addition, a primer layer is optionally provided between the phosphor-containing layer and the substrate to adhere the layer closely to the substrate.

The X-ray intensifying screen used in the film / screen system according to the present invention can be self-supported or supported. X-ray intensifying screens generally comprise a support (also referred to as a substrate), at least one layer comprising phosphor particles dispersed in a suitable binder and a phosphor to protect said layer during use in the following order: A protective coating coated over the containing layer. In addition, a primer layer is optionally provided between the phosphor-containing layer and the substrate to adhere the layer closely to the substrate. Preferably, a plastic film is used as the support material. Depending on the speed grade of the screen, where a synergistic effect is achieved in a relationship between speed and sharpness, a support characterized by a reflection characteristic expressed as% reflectance over a wavelength range of 350-600 nm is described, for example, in US Pat. No. 5,381,015. Especially used as done. Such a support can be a highly light-reflective support such as, for example, polyethylene terephthalate containing white pigments (eg, BaSO ₄ , TiO _2, etc.), or it can be, for example, polyethylene containing a black pigment (eg, carbon black). It can be a support that absorbs light, such as terephthalate. Substrates containing dyes or pigments that absorb light of a particular wavelength can be useful in the manufacture of X-ray intensifying screens in film / screen systems according to the present invention. In most applications the phosphor layer will contain sufficient binder to provide structural cohesion into the layer.

Mixtures of two or more of these binders may be used, for example, a mixture of polyethyl acrylate and cellulose acetobutyrate. The weight ratio of phosphor to binder is generally 50:50 to 89:11, preferably 80:20.
~ 89: 11.

The screen used in the screen / film system according to the invention is described in EP-A 0647258.
And a supported layer of phosphor particles dispersed in a binding medium comprising one or more rubbery and / or elastomeric polymers as described in US Pat. Thus, 90:10 or more, more preferably at least 9
A pigment to binder media weight ratio of 3: 7 (eg 98: 2) can be obtained, with good image resolution plus good adhesion properties between the support and the phosphor layer and good elasticity of the screen. The result is a high degree of ease of handling.

After formation of the phosphor layer, a protective layer is generally provided on top of the phosphor layer. In a preferred embodiment, the protective coating is 1-50
With a layer thickness d of μm, the embossed surface roughness is applied for high ease of handling, thereby avoiding sticking, friction and electrostatic attraction while maintaining good image resolution.
The embossed protective layers are EP-A 0510753 and 05
Can be provided on the phosphor layer to protect against mechanical and chemical damage as described in 10754. Assemblies which provide a means for reducing the crossover to less than 10% for radiation having a wavelength longer than 300 nm are described, for example, in US Pat. No. 5,259,016.

According to the present invention there is provided a black-and-white image forming method, said method comprising the step of adhering the film material according to the present invention between a pair of supported or self-supported X-ray intensifying screen sandwiches (the said pair of Supported or self-supported X-ray intensifying screens have at least 50% of their emitted radiation in the wavelength range where the materials are spectrally sensitized.
Exposing the film to X-rays that pass through the subject (the X-rays being, for example, 7 μm).
Has an energy of 0-100 keV, is in intimate contact with the screen, and preferably has a low energy);
Processing the film by the steps of developing, fixing, rinsing and drying.

It is preferable that the processing is performed by an automatic processor. More particularly, for processing the film material of the present invention, an automatically operating device, preferably with a system for automatic replenishment of the processing solution, is used. Dry-to-dry processing of the material coated from a low amount of silver within a short processing time of 30 to 90 seconds, more preferably 30 seconds to less than 60 seconds, renders the material preferably a hardener-free developer Developing the material in a fixer, optionally without a curing agent; rinsing and drying the material.

The structure usually used in the processing apparatus shows a continuous tank unit corresponding to a developer, a fixer and a rinse as a continuous solution. However, recent developments have shown that the order of developer-fixer-fixer-rinse-water-rinse-water as a continuous solution is preferred from an ecological point of view and in particular with regard to the reduction of replenishment. One washing step between development and fixing and one washing step at the end before drying may be present.

Since ecologically low replenishment is a major problem with the present invention, concentrated hardener-free processing solutions are used in one package.

An example is disclosed in US Pat. No. 5,187,050.
And 5,296,342. Particularly preferred developers containing ecologically acceptable developing agents such as ascorbic acid and its derivatives are described in EP-A 0732619 and US-A 5,593,817 and 5604082. Instead of or partly (e.g. a 1: 1 to 9: 1 weight ratio) substitution for the ecologically problematic "hydroquinone", (iso) ascorbic acid, 1-
Ascorbic acid and tetramethyl reductic acid are preferred as main developing agents in the developer. The developing agent is E
PA 0461783, 0498968, 06903
43,0696959,0704756,073261
9,073381 and 0731382, US-A5
474879 and 5498511 and Research Disclo
sure No. 371052, issued March 1, 1995, wherein a general formula covering the formula of the developing agent is represented. Particularly preferred developers to reduce the "sludge formation" provided by solubilizers such as sulfite, which are present in the developer as preservatives, include antioxidants and primary antioxidants, referred to as "low sludge" developers. It contains reduced amounts of ascorbic acid and sulphite acting as a developer. A preferred measure that can be taken is EP application N
o. 99201891 and 99201892, both filed concurrently on June 14, 1999.

For ecologically favorable fixation, the presence of aluminum ions should be reduced, and more preferably no aluminum ions should be present. It is also preferred in the absence of "sludge" formation, a phenomenon that leads to pi-line defects when high amounts of silver are coated on the photosensitive layer. Means for reducing "sludge formation" are further described in US-A 54
47817, 5462831 and 5518868. A particularly preferred fixer contains less than 25 g of potassium sulfite per liter in the absence of acetic acid, said fixer having a pH value of at least 4.5 to render the fixer almost odorless. However,
For whatever reason, if aluminum ions are present in the fixer composition, the presence of the α-ketocarboxylic acid compound may be as described in EP-A 0 620 483,0726,491 and RD 16768 (issued March 1978). Recommended for Sodium thiosulfate can be used as a fixative, thus avoiding the commonly used ammonium ions which are ecologically undesirable. Fixation times reduced to about 2 to 10 seconds can be achieved for low coverage chloride-rich emulsion crystals. More particularly, regeneration is kept to a minimum in the processing of materials coated with reduced amounts of silver halide as in the present invention.

Although the use of hexagonal {111} tabular emulsion grains in a double-sided coating material as in the present invention is claimed, low halo and X-ray irradiance are advantageous for image sharpness used in mammography. It is clear that this does not preclude the use of such emulsions in one-sided coating materials, whether for radiographic applications (as already mentioned) or in combination with a single screen with a luminescent phosphor having a high promptness. . For example, Med. Phys. 5 (3), 20
5 (1978). Other single-sided coating materials to which the emulsions described above can be advantageously applied, for example, with respect to storage properties, developability, etc. are, for example, mammography, aerial photography, black and white cinema films, laser films or hard copy films and graphic or reprographic applications. Black-and-white silver halide material. Its use in color photographic applications may also be useful.

Having described preferred examples of the invention in detail,
It will be understood by those skilled in the art that the scope of the present invention is not limited to the following examples which illustrate the present invention.

[0075]

EXAMPLE 1 Preparation of Tabular Emulsion A ₃ liters of deionized water at 51 ° C., adjusted to a pH of 2.5 by adding H ₂ SO ₄ and stirred below a speed of 600 rpm. Solution of 6.9 g of oxidized gelatin at 0.98 M AgNO in double jet method
₃ (hereinafter referred to as A1) and 0.98 M KB
An aqueous solution of r (hereinafter referred to as B1) was added:
25 ml A1 and 25 ml B1 were added at 30 second time intervals. After the addition is complete, add 7
The temperature was raised to 0 ° C .: controlling the UAg (mV vs. A
g / AgCl (saturated) Reference electrode), 70 ° C ± 1 ° C
At a temperature of 44.5 ± 5 mV. After 1 minute, the pH was set to a value of 5.0 ± 0.3 and immediately thereafter
A solution of 50 g of inert gelatin in 500 ml of deionized water at 0 ° C. was added. After 3 minutes, B1 was added at a rate of 7.06 ml / min for 120 seconds while at the same time 7.5
A1 was added by double jet at a rate of ml / min. In a further double jet addition from 7.0 to 21.11 ml / min for A1 and 7.0 for B1.
A at a rate increasing linearly from 6 to 21.29 ml / min.
1 and B1 were added for 2822 seconds and +
A constant UAg potential of 40 mV was maintained. After 5 minutes, A1 and B1 were simultaneously added by double jet at a rate of 10.0 and 10.04 ml / min for 60 seconds, respectively, thereby keeping the UAg value at a constant value of 50 mV, while 81 minutes 5 seconds The flow rate was 46.4 each over the entire time.
It increased to 9 ml / min and 46.69 ml / min.

After the double jet addition period, the ultrafine (about 0.040 μm) dissolved in 20 g of deionized water at 40 ° C.
m) Add the amount of emulsion with 100% AgI crystals to the reaction vessel and add 0.1 mol% total Ag, based on silver precipitated.
An I content was obtained at the end of the precipitation.

The tabular silver bromoiodide # 11 thus prepared
1 The average grain size of the emulsion grains is 0.53 μm when expressed as an equivalent volume diameter, and the average thickness is 0.12 μm.
Met.

After the washing, when expressed as AgNO ₃ , 23
0.5 g / kg silver halide content and 72.6 g / kg
Gelatin and water were added to obtain a gelatin content of kg. An emulsion weighing 3442 g, pH adjusted to 5.5, was divided into ten equal portions. To each part was continuously added 4 ml of a 1% by weight KSCN solution, x ml (0.4% by weight) of an azacyanine dye corresponding to the following formula dissolved in 18 ml of methanol, and 5 minutes later, 2 m
A 4.76 × 10 ⁻⁵ M solution of sodium toluenethiosulfonate in 1 liter of methanol was added, and an additional 5
After one minute, 1200 ml of anhydro-5,5'-dichloro-3,3'-bis (n-propyl-3-sulfonate)
-9-ethyl-benzoxa-carbocyanine triethylammonium salt, y mg of 35 ° C deionized water 10
Sodium thiosulfate dissolved in ml, z ml 2-
A 0.001% by weight solution of carboxyethyl-N-benzothiazine selenide, 1.456 × 10 5 wml
Solution containing ^-3 M chloroauric acid and 1.58 x 10 ^-2 M rhodanide, and finally 10 ml of 1-
A 1% by weight solution of (p-carboxyphenyl) -5-mercapto-tetrazole was added.

Ten emulsion samples whose x, y, z and w values are given in Table 1 were chemically aged at 50 ° C. for the time to obtain the best compromise between fog and sensitivity. After cooling,
Phenol was added as a preservative.

[0080]

Embedded image See formula (I.3) (provided that it has a counter ion as in (I.5) above)

[0081]

[Table 1]

The following coatings, summarized in Table 2, were added to the emulsion before coating the emulsion layers:

[Table 2]

The following protective layer was coated on both sides (p
H value: 6.25) (see Table 3).

[Table 3]

[0084]

Embedded image

The photographic materials according to these examples contain one emulsion layer and one protective layer. The emulsion layer coating solution was prepared by adding a solution of the compound shown in Table 2 to the chemically ripened emulsion sample No. 1-10 which was melted with stirring. The coating solution for the protective layer is given in Table 3.

After adjusting the pH to 6.7, the viscosity and surface tension of the coating solution were optimized according to the conditions of the coating method. The emulsion layer and the protective layer were simultaneously coated on one side of a primed polyester support having a thickness of 175 .mu.m by conventional coating techniques. Silver coverage of the emulsion was about 5-5.5g / ^{m 2} when expressed as the equivalent amount of silver nitrate.

A separate strip of coating material was subsequently applied to U5
Exposure to white light filtered through a 35 green light filter for the same exposure time of 2 seconds. Development was carried out for 12 seconds in a developer having the following composition: hydroquinone 30 g 1-phenyl-pyrazolidin-3-one 1.5 g acetic acid 99% 9.5 ml potassium sulfite 63.7 g potassium chloride 0.8 g EDTA-2Na 2.1 g Potassium carbonate 32 g Potassium metabisulfite 9 g Potassium hydroxide 14 g Diethylene glycol 25 ml 6-Methylbenztriazole 0.09 g Glutardialdehyde 50% by weight 9.5 ml 5-Nitroindazole 0.25 g Make up to 1 liter with deionized water.

The starting solution added had the following composition: Acetic acid 99% 15.5 ml KBr 16 g Make up to 100 ml with deionized water.

The developed photographic strips were fixed in a conventional fixing bath containing, for example, sodium thiosulfate and potassium metabisulfite, then rinsed with water and dried.

The sensitometric properties of these filmstrips are given in Table 4. Sensitometry results are fog F (number increased 1000 times), speed S
(Number increased by a factor of 100: the lower the number, the emulsion is more sensitive); a reduction of 30 units is equivalent to a doubling of speed), the overall contrast GG (number increased by a factor of 100: gradation Above, measured from characteristic curves over a concentration range of 1.75, starting from a concentration value of 0.25 to 2.00) and covering power CP (calculated as maximum concentration per gram of coated silver) Was shown for Sensitometric data were obtained by developing in a developer having the composition shown above during a total development time of 12 seconds.

[0091] Further, the image tone from the number that corresponds to the _{D r,} evaluated, displayed as "IT". Data were summarized with respect to D _{b =} 2 concentrations concentrations were measured through a red filter in D _r after blue filters: The higher this number (increased numbers 100 times) is high, the color of the developed silver Good (more desirable blue-black instead of unwanted red-brown). A difference of 0.02 is considered significant as visually recognizable.

[0092]

[Table 4]

As can be concluded from Table 4, site-directing in the chemical sensitization of thin tabular {111} silver bromoiodide grains .
The presence of a sufficiently high amount of azacyanine as a compound in the photosensitive silver halide photographic emulsion provides the desired high speed, high contrast and increased coverage without loss of image tone. Furthermore, the image tones seem slightly better based on the numbers obtained. Comparative emulsion and corresponding material No. 1-5 are emulsions of the present invention and corresponding material No. 6
Obviously inferior to -10: in addition to a considerable speed increase (up to 8 times!), A considerable increase in the covering power is achieved without a loss of image tone. These results relate to the relationship thus achieved between coverage and image tone.
It is concluded that there is at least an explanation for the breakthrough in

Such a large amount of site-directed compounds (formula (I.
See 3). However, due to the presence of the above-mentioned (I.5), a small shallow color shift at the absorption maximum of the material from 547 nm (comparative material) to 544 nm (material of the present invention) for visible (green) light. ). However, for example, it has no other negative consequences on the achievable speed.

Example 2 The same emulsion as in Example 1 was prepared again. After washing, AgNO
Gelatin and water were added to obtain a silver halide content of 230.5 g / kg, designated as ₃ , and a gelatin content of 72.6 g / kg. The emulsion whose pH was adjusted to 5.5 was divided into four equal portions, and emulsion No. 11-
The number 14 was given. To each part was successively added 4 ml of a 1% by weight KSCN solution per equivalent of 500 g of silver nitrate, and an azacyanine dye corresponding to the same formula as in Example 1 dissolved in 18 ml of xml (1% by weight) of methanol.
After a minute, a 4.76 × 10 ⁻⁵ M solution of sodium toluenethiosulfonate in 2 ml of methanol was added, and after another 5 minutes w′ml of anhydro-5,5′-
4. a 0.25% by weight solution of dichloro-3,3'-bis (n-propyl-3-sulfonate) -9-ethyl-benzoxa-carbocyanine triethylammonium salt;
Sodium thiosulfate dissolved in 5 mg 35 ml of deionized water 10 ml, 7 ml 2-carboxyethyl-N-
A 0.001% by weight solution of benzothiazine selenide,
A solution containing 9.0 ml of 1.456 × 10 ⁻³ M chloroauric acid and 1.58 × 10 ⁻² M ammonium rhodanide, and finally 10 ml of 1- (p-carboxyphenyl) -5-mercapto- A 1% by weight solution of tetrazole was added.

[0096]

[Table 5]

An equivalent amount of the same coating equivalent to about 5 g of AgNO ₃ per m ₂ was prepared as in Example 1 and the strips thus obtained were numbered Material Nos. 11-14. After exposure and treatment as in Example 1, the following results summarized in Table 6 were obtained.

As can be concluded from the data in Table 6 below, a higher amount of the azacyanine dye allows the addition of a lower amount of the spectral sensitizer without compromising sensitometry,
It also favors better decolorization and less residual color after processing. When such high amounts of azacyanine dyes are added, an improved image tone and an improved relationship between image tone and coverage are clearly confirmed.

[0099]

[Table 6]

Example 3 Preparation of Tabular Emulsion A ' 3 l of deionized water at 55 ° C., adjusted to a pH of 2.0 by adding H ₂ SO ₄ and stirred at a speed below 600 rpm Solution of 7.5 g of oxidized gelatin at 0.98 M AgNO by double jet method
₃ (hereinafter referred to as A1) and 0.98 M KB
An aqueous solution of r (hereinafter referred to as B1) was added:
30 ml A1 and 30 ml B1 were added at 30 second time intervals. The temperature was raised to 70 ° C. over 32 minutes: UAg was controlled and 44.5 ± 5 mV (Ag /
(Measured against an AgCl (saturated) reference electrode). The pH was set to a value of 5.0 ± 0.3, immediately after which a solution of 50 g of inert gelatin in 500 ml of 70 ° C. deionized water was added.

Three minutes later, B1 was added at a rate of 7 ml / min for 120 seconds, and at the same time, A1 was added at a rate of 7.23 ml / min.
Was added by double jet. 7.0 to 21.11 for A1 in further double jet addition
7.23 to 21.74 ml for B1 to ml / min
A1 and B1 at a rate of 2808
For 10 seconds and a constant UAg of +10 mV in the reaction vessel
The potential was maintained. After 4 minutes and 22 seconds, A1 and B1 were simultaneously added by double jet at a rate of 10.0 and 10.14 ml / min for 60 seconds, respectively, during which the UAg value was 3
It was held at a constant value of 0 mV and the flow rate was 46.39 ml / min and 4 respectively over the entire time of 80 min 52 sec.
Increased to 7.04 ml / min.

After the double jet addition period, the ultrafine (about 0.040 μm) dissolved in 20 g of deionized water at 40 ° C.
m) The amount of emulsion with 100% AgI crystals was added to the reaction vessel in 2 minutes and 0.1 mol% based on the silver precipitated
Was obtained at the end of the precipitation.

The thus prepared silver bromoiodide tabular # 11
1｝ The average grain size of the emulsion grains is 0.43 μm when expressed as an equivalent volume diameter, and the average thickness is 0.09 μm.
Met.

After washing, when expressed as AgNO ₃ , 23
0.5 g / kg silver halide content and 72.6 g / kg
Gelatin and water were added to obtain a gelatin content of kg. An emulsion weighing 3442 g, pH adjusted to 5.5, was divided into ten equal portions. To each portion, 4 ml of a 1% by weight KSCN solution, x ml (0.4% by weight) of an azacyanine dye corresponding to the following formula (see also Example 1) dissolved in 18 ml of methanol were added successively, After a minute, a 4.76 × 10 ⁻⁵ M solution of sodium toluenethiosulfonate in 2 ml of methanol was added and after another 5 minutes, y′ml of anhydro-5
5'-dichloro-3,3'-bis (n-propyl-3-
Sulfonate) -9-ethyl-benzoxa-carbocyanine triethylammonium salt 0.25% by weight solution, sodium thiosulfate in an amount to obtain an optimal fog-speed relationship, 2-carboxyethyl-N-benzothiazine selenide And chloroauric acid. Finally one
0 ml of a 1% by weight solution of 1- (p-carboxyphenyl) -5-mercapto-tetrazole was added.

[0105]

Embedded image See formula (I.3). However, it has a counter ion as in the formula (I.5).

Seven emulsion samples, for which x and y 'values were given in Table 5, were chemically ripened at 50 ° C. for a time to obtain the best compromise between fog and speed. After cooling, phenol was added as a preservative. Coating (at an average coverage of about 4 g, expressed as equivalents of silver nitrate) of the material of Example 1
No. 1-10. Material No. 15-
21 was exposed, processed and evaluated in the same manner as in Example 1.

The results obtained for fog, speed, covering power, image tone and crossover% are summarized in Table 7.

The crossover percentage (CO%) was determined as follows. Samples coated on both sides with a single green light emitting screen (CURIX Ortho Regular, Agfa-Gevaert NV,
(Trademark product from Mortsel, Belgium) and white paper replacing the second screen. This film-screen material with its light emitting screen directed to the X-ray tube is
Exposure was performed with varying doses of radiation indicated as gE (exposure). After processing, the minimum dose required to obtain a density of 0.5 on the fog is from the front layer (before log E) and from the rear layer (log E).
Later). The crossover percentage was then calculated from the following formula:% CO = 100: antilog (after log E-before log E)

[0109]

[Table 7]

From the data summarized in Table 7, a high amount of
Zacyanine site-directed compound (less per mole of silver
0.1 mmol) and a high amount of green sensitizing dye
Optimized speed for materials with ultrathin {111} tabular grains can be concluded that it is achievable when standing (see present invention emulsion material No.19 pairs No.16).

There was no adverse effect on the crossover percentage (expressed in terms of image sharpness) (Material No. 1)
9 and 20), a significant covering power is calculated in addition to the good comparable image tones for both inventive samples.

Thus, it can be concluded that the increase in covering power does not adversely affect the image tone of the image obtained after processing.

Having described preferred examples of the invention in detail,
It will be apparent to those skilled in the art that numerous modifications may be made therein without departing from the scope of the invention as defined in the appended claims.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G01T 1/00 G01T 1/00 B G03C 1/00 G03C 1/00 A 1/12 1/12 1/14 1/14 1/18 1/18 1/29 1/29 1/46 1/46 5/17 5/17 G21K 4/00 G21K 4/00 A (72) Inventor Paul Curran, Morseur, Belgium, Septoflat 27 Inside Agfa Geverd Namroze Bennoutchap (72) Inventor Freddie Andricks Septetrat, Mortzeel, Belgium 27 Inside Agfa Gevaert Namloze Bennoutchap

Claims (7)

[Claims] Claims: 1. A transparent support and a small support on one or both sides thereof.
Photosensitive silver halide containing at least one photosensitive emulsion layer
A photographic film material, wherein said photosensitive emulsion layer comprises two
Rich in silver bromide with flat and parallel {111} crystal faces,
It also has silver iodide in an amount of less than 3 mol% based on silver
, Spectrally and chemically sensitized tabular halo
Silver iodide particles (i) (wherein said particles are at least 5
0% of the total projected surface of the parallel crystal planes in the emulsion
Product, and at least an average aspect ratio of 2: 1
Ratio, having a particle thickness of 0.05 to 0.15 μm),
1 × 10 per mol of silver covered^-4More than mol
Site orientation satisfying the general formula (I.1) or (I.2)
Compound (ii) and one or more J-aggregation spectral sensitizing dyes (i
ii) the site-directed compound and the J-aggregated spectrum
Wherein the molar ratio between the sensitizing dyes exceeds 50%.
1｝ At least 1: 6 for the particle coverage of tabular grains
Wherein the site-directed compound is of the formula (I.1) or (I.
Photosensitive halogen represented by 2)
Silver halide photographic film material:Wherein the substituent R¹-R⁴Are each independently hydrogen,
Substituted or substituted) alkyl, (unsubstituted or substituted) aryl or
Represents an (unsubstituted or substituted) aralkyl group; ¹And R
²And / or R³And R⁴Is (substituted or unsubstituted) benzo
May form a ring, which, if substituted,¹-R⁴
Having the same or different substituents as R;
Alkyl), (unsubstituted or substituted) aryl or (unsubstituted)
R ′ represents hydrogen, (unsubstituted or substituted) aralkyl group;
Substituted or substituted) alkyl, (unsubstituted or substituted) aryl or
Represents an (unsubstituted or substituted) aralkyl group;
The anion exists as a charge compensating ion. 2. The molar ratio between the site-directing compound and the J-aggregation spectral sensitizing dye is from 1: 3 to 1: 1.
The described material. 3. The {111} tabular silver halide grains occupy at least 50% of the total projected surface area of the grains and have an aspect ratio of at least 5: 1, from 0.3 μm to 3.0 μm.
A material according to claim 1 or 2, having an average crystal diameter of 0 µm and an average thickness of less than 0.30 µm. 4. The method according to claim 1, wherein the silver bromide-rich particles comprise 0.1 mol%.
The material according to any one of claims 1 to 3, having silver iodide in an amount of 0.4 mol% to 0.4 mol%. 5. The silver halide grain according to claim 1, wherein the silver halide grains are sensitive to irradiation in the wavelength range of 540 to 555 nm due to the presence of a J-aggregation spectral sensitizing cyanine dye corresponding to the general formula (II). Materials described: Wherein Z and Z ′ each independently represent a nitrogen or oxygen atom; Z is substituted with R ⁸ if Z is a nitrogen atom;
Z 'is if Z' is substituted with R ⁹ if it is a nitrogen atom;
R ^5, R ⁶ and R ⁸ and R ⁹ each independently represents a substituted or unsubstituted alkyl; R ⁷ is hydrogen, a substituted or an unsubstituted alkyl or substituted or unsubstituted aryl; T and T 'are each independently Represents hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl or substituted or unsubstituted heterocyclic groups;
(X ⁻ ) _p represents a negatively charged atom or group of atoms for compensating for the positive charge present on the dye; (M ⁺ ) _q represents a positive number for compensating for the negative charge present on the dye. Represents a charged atom or group of atoms, and p and q each represent an integer for obtaining an electronically neutral compound. 6. A radiographic screen / film combination comprising a photosensitive silver halide photographic film material according to claim 1 in combination with a supported or self-supporting X-ray intensifying screen, A radiographic screen / film combination, characterized in that the self-supporting X-ray intensifying screen consists essentially of luminescent phosphor particles emitting green light radiation in the wavelength range of 540 to 555 nm. 7. A black-and-white image forming method comprising the steps of:-adhering the film material according to any one of claims 1 to 5 between a pair of sandwiches of a supported or self-supported X-ray intensifying screen; A pair of supported or self-supported X-ray intensifying screens comprises luminescent phosphor particles that emit at least 50% of their emitted radiation in the wavelength range where the material is spectrally sensitized); Exposing the film material to X-rays passing through the subject (the X-rays having an energy of 70-100 keV and in intimate contact with the screen);-developing, fixing, rinsing and drying the film material To process.