JPH08211519A - Radiographic product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a product capable of obtaining an image free from residual yellow coloring. SOLUTION: This radiographic product contains, gelatin, at least one photosensitive silver halide flat grain emulsion spectrally sensitized with a spectral sensitizing pigment of blur area having an emission peak between 400-500nm, and a fluorescent whitening agent derived from 4,4'-diaminostilbene disulfonic acid having at least three anionic sulfa groups, and present in the photosensitive layer of the radiographic product or situated in at least one layer between the photosensitive layer and a support body. In the application to a radiographic system, it also contains an intensifying screen.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a silver halide photographic product used in radiography in combination with an X-ray intensifying screen. More specifically, the present invention relates to radiographic systems comprising at least one layer of spectrally sensitized tabular silver halide emulsion and an intensifying screen. The present invention is directed to residual colorin in low exposure areas of radiographic images.
It avoids the problem of g), also referred to in the art as "dye stain", while at the same time allowing a wide range of spectral sensitizers to be used.

[0002]

BACKGROUND OF THE INVENTION In radiography, especially medical radiography, radiographic systems, including intensifying screens and silver halide photosensitive products, are commonly utilized.
The use of intensifying screens can reduce the amount of X-rays needed to obtain a radiograph, and thus the amount of X-rays absorbed by the patient. Intensifying screens have a maximum emission (maximum emissi
on). The silver halide photosensitive products used in radiography with intensifying screens have
It preferably comprises a transparent support coated on both sides with at least one layer of a spectrally sensitized silver halide emulsion.

Silver halide grains are essentially sensitive to blue light, but by adsorbing a spectral sensitizing dye on their surface, they are blue and / or green and / or in the visible spectrum. Or it will have maximum absorption in the red region. In practice, the spectral sensitizing dye is chosen so that the maximum absorption of the silver halide grains lies in the maximum emission area of the intensifying screen. For example, 360-500 nm
Intensifying screens that emit in the blue region and spectral sensitizing dyes in the blue region that have maximum absorption in this range are used. Tabular grain silver halide emulsions are known to be useful in radiographic products.

For example, US Pat. No. 4,639,411 describes a radiographic element containing an emulsion of tabular silver halide grains capable of forming a latent image when exposed to light. Preferably the emulsion consists of tabular grains having a thickness of less than 0.5 µm and an aspect ratio higher than 5: 1. Tabular grain emulsions require high levels of sensitizing dye due to the very specific surface areas of the grains.
Certain spectral sensitizing dyes cause residual coloration in the radiographic image in the unexposed or only slightly exposed areas. For example, if the dye is a spectral sensitizer in the blue region, the image will be colored yellow in low density regions. This problem is especially serious in rapid processing, which is carried out within 1 minute and has a very short immersion time in the processing solution.

In order to avoid this phenomenon, it is necessary to use spectral sensitizing dyes which do not give rise to any residual color, limiting their choice. The present invention allows the use of spectral sensitizing dyes which, when used alone in large amounts, produce residual color in low density image areas. According to the invention, this coloration is avoided by involving an optical brightener with special properties. One of the advantages of the present invention is that it offers a great deal of freedom in the choice of spectral sensitizing dyes. In addition, surprisingly, the sensitometric properties of the radiographic image are not substantially impaired by the presence of the optical brightener according to the invention. Optical brighteners that have been known for a long time are substances that absorb ultraviolet light in the spectral region between 300 and 400 nm and that are fluorescent in the blue region of the visible spectrum.

They are used to improve the whiteness of photographic paper and photographic film. Research Disclosure, July 1983, No
23136, inter alia, describes the use of optical brighteners in radiographic systems. According to this article, the presence of optical brightener suppresses the yellow appearance of the supporting polymer when a UV source is used. The optical brightener is incorporated into a layer placed on the support or is incorporated into the support by dipping the support in a solution containing the optical brightener, such as a developing or fixing solution or a stabilizing bath. To be This paper does not address the problem of residual coloring due to spectral sensitizing dyes.

In US Pat. No. 4,232,112 a developer or bleach / fixer was derived from a bleaching agent which is a derivative of 4,4'-diamino-stilbenedisulfonic acid and benzenesulfonic acid or naphthalenesulfonic acid. A process for developing a color photographic film containing a second compound is described. This process can, on the one hand, prevent residual coloring due to the oxidation of the color developing agents in the bleach / fix solution and, on the other hand, prevent residual coloring due to the accumulation of various substances at the edges of the film. In U.S. Pat.No. 4,587,195,
A method for eliminating residual coloring of color images is described. For this purpose a developer is used which comprises a mixture of triazyl stilbene type optical brighteners with slightly shifted absorption peaks.

US Pat. No. 5,238,793 describes a method of processing a black and white film containing a layer of a silver halide emulsion spectrally sensitized with a cyanine dye. When the replenishment rate of the processing solution is low or the level of the sensitizing dye is high, the spectral sensitizing dye forms solid particles in the processing solution, which adhere to the surface of the film and are small spots or large in the final image. Form a blot. To avoid this phenomenon, the exposed film is placed in contact with a processing solution containing a compound capable of dissolving the spectral sensitizing dye. The solubilizing compound is a stilbene derivative that is incorporated into the processing solution where solid particle formation is a concern, but it can also be incorporated into photographic elements. This patent does not carry out this possibility, and it does not contain any disclosure regarding the placement of solubilizing compounds in photographic elements.

The problem of residual coloration solved by the present invention is quite another, not due to the accumulation of solid particles in the processing solution, but the absorption of residual spectral sensitizing dyes in the gelatin of radiographic products. It is due to. Therefore,
Radiographic images, especially the problem of residual coloration after rapid processing, has not been solved by the prior art when the emulsions contain certain spectral sensitizing dyes and the cited document is intended to solve this problem. There is no disclosure or suggestion of using optical brighteners in.

[0010]

Further, one of the objects of the present invention is
One is gelatin, at least one light sensitive silver halide tabular grain emulsion, and said radiographic image in a radiographic image in an amount sufficient to cause residual yellow coloring due to absorption of aggregates of residual dye in gelatin. A radiographic product comprising a support and at least one photosensitive layer containing a spectral sensitizing dye in the blue region present in the product and having an emission peak between 400 and 500 nm, as well as an optical brightener. The optical brightener comprises: a) having at least three anionic sulfo groups 4,
A derivative of 4'-diaminostilbenedisulfonic acid, b) present in at least one light sensitive layer of the radiographic product or in at least one gelatin layer located between the light sensitive layer and the support. A radiographic product characterized by: What is an anionic sulfo group?
By ionized —SO ₃ — group bound to a cation that counterbalances the acid group —SO ₃ H and balances the ionic charge. Another object of the invention is a radiographic system comprising at least one X-ray intensifying screen with a maximum emission of 360-500 nm and said radiographic product.

[0011]

DETAILED DESCRIPTION OF THE INVENTION The emulsion according to the present invention is an emulsion containing tabular grains of silver chloride, silver bromide, silver iodide or a mixture thereof as a binder. The binder is a water-permeable hydrophilic colloid such as gelatin, gelatin derivative, albumin, polyvinyl alcohol, polyvinyl polymer and the like. Emulsions are described in U.S. Pat.
It may be cured according to one of the methods described in 66. Hardeners that may be used are Research Disclosure, December 1989, No 30811.
Listed in 3, Section X.

In addition to the properties detailed above, the emulsions may contain other compounds such as antifoggants, stabilizers or antifouling agents. The radiographic film may include an overcoat containing a matting agent.
The overcoat or photosensitive layer may include a plasticizer or lubricant. These compounds are
Research Disclosure, Vol 184,
No. 18431, August 1979.

These silver halide emulsions of the present invention are commercially available from Research Disclosure,
It is chemically sensitized according to conventional chemical sensitization methods described in December 1989, No 308119, Section III, preferably with sulfur and / or gold and / or selenium. The emulsion of the present invention is spectrally sensitized. Conventional spectral sensitization methods that can be used within the scope of the present invention are described in Research Disclosure, December 1989, No 308119,
It is described in Section IV. The spectroscopic dyes that can be used in the present invention are blue spectroscopic dyes, such as cyanine or merocyanine dyes, which tend to cause residual coloring. Cyanine dyes are available from Research Disclosure (Research D
isclosure), December 1989, No 308119, Section IVA-C
It is described in. Cyanine dyes that can be used according to the invention correspond to the formula:

[0014]

Embedded image

In the above formula, Z ₁ and Z ₂ represent atoms necessary for completing a substituted or unsubstituted aromatic ring structure;
R ₇ and R ₈ each independently represent a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, which is substituted with a halogen, alkoxy, aryl, aryloxy, sulfo or carboxy group. L ₁ , L ₂ and L ₃ each independently represent a substituted or unsubstituted methine bond; X is O, S, Se,-.
C- or N-, and N is 0, 1 or 2. Specific examples of cyanine dyes that tend to cause residual coloring include
It is as follows.

[0016]

Embedded image

[0017]

Embedded image

[0018]

[Chemical 4]

The optical brightener which can be used in the present invention is capable of destroying the aggregate of the residual sensitizing dye in gelatin,
They will reduce the optical density corresponding to residual coloration, giving rise to species with absorption peak wavelengths in the visible spectral region where eye sensitivity is low, preferably around wavelengths below 420 nm. In addition, these optical brighteners
It will have a sufficient number of solubilizing groups so that it can remain in the gelatin in the layers of the photographic product. A specific example of the optical brightening agent that can be used in the present invention is a stilbene type compound having at least three anionic sulfo groups. For example, the compound represented by the following formula can be used.

[0020]

Embedded image

In the above formula, R ₁ , R ₂ , R ₃ and R ₄ are
Each of the following groups,

[Chemical 6]Halogen, hydrogen, hydroxy, substituted or unsubstituted
Alkyl, substituted or unsubstituted aryl, substituted or
Selected from unsubstituted alkoxy and sulfo, R_FiveOh
And R₆Are each independently hydrogen, substituted or unsubstituted
Among alkyl and substituted or unsubstituted aryl
M is a cation that balances the ionic charge.
Provided that the compound is at least one solubilized
R is an anionic sulfo group₁, R ₂, R₃Or R_FourTo
Have.

Specific examples of useful compounds are described in the aforementioned US Pat.
It is described in Table I of 5,238,793. Preferred compounds according to the invention have the formula

[Chemical 7] Phorwite ™ and the formula

Embedded image Is Tinopal ™.

The amount of optical brightener is determined so that the residual coloration by the spectral sensitizing dye is greatly reduced without compromising the sensitometric or physical properties of the radiographic product. In particular, it is desirable that photographic speed, reciprocity failure, pressure sensitivity and maintenance of fog / speed ratio during incubation be substantially unchanged. A suitable amount of optical brightener is 0.05 to ² mg / dm ² , and preferably 0.5 to 1.5 mg / dm ² .

In addition to radiographic film, radiographic systems generally include a pair of x-ray intensifying screens located on either side of the radiographic film. The intensifying screen used in the present invention has an emission peak in the blue or ultraviolet region with a wavelength of 360 to 500 nm. X-ray intensifying screens include one or more fluorophores in a mixture with a binder. The fluorophore particle size is generally 0.5-20 μm, and preferably 1-10 μm. A specific example of a fluorescent substance that emits light in the blue or ultraviolet region is calcium tungstate CaW.
Lanthanum oxybromide LaOBr activated by O ₄ , terbium or thallium, Gadolinium oxybromide activated by yttrium or cerium, activated by gadolinium, bismuth, lead, cerium
YTaO ₄ , europium, gadolinium, lanthanum or yttrium activated barium fluorobarium BaFCl, or europium or strontium activated barium sulphate.

Binders which can be used are organic polymers which are transparent to light and X-rays, for example vinyl alcohol and o-sulfobenzaldehyde acetal polymers, chlorosulfonated polyethylenes, bisphenol polycarbonates, alkyl acrylate and methacrylate copolymers and polyurethanes. To be selected from. Another binder that can be used within the scope of the present invention is U.S. Patent Nos. 2,502,529 and 2,887,379.
No. 3,617,285, No. 3,300,310, No. 3,300,
311 and 3,743,833 and Research Disclosure, Vol 15
4, listed in February 1977. Preferred binders are polyurethanes such as Estane ™, Permut
hane ™ and Cargill ™. The X-ray intensifying screen may include a protective layer and a reflective layer in addition to the fluorescent layer. The manufacturing method of the intensifying screen and the radiographic film is
Research Disclos
ure), No 18431. The following examples serve to illustrate the invention.

[0026]

【Example】

Examples 1-3 The films described in Examples 1-3 are in the following order:
It consists of a layer of tabular grain silver bromide emulsion having a grain equivalent diameter of 2.14 μm and an average grain thickness of 0.11 μm, and an Estar ™ support coated with a gelatin overcoat. In Example 2, the film also includes a layer of gelatin located between the emulsion layer and the support. The film is hardened with bis (vinylsulfonylmethyl) ether and the amount of hardener is 2. of the total dry gelatin contained in the film.
Equal to 25% by weight. The emulsion is sulfur (KSCN per mole Ag)
150 mg), gold (Na ₃ (S ₂ O ₃ ) ₂ Au, 2H ₂ O 5.06 per mole of Ag)
optimally chemically sensitized with selenium (0.67 mg of KSeCN per mol of Ag) and selenium. The emulsion is optimally spectrally sensitized with spectral sensitizing dye A.

A sample of film is exposed to blue light that mimics the exposure obtained through an intensifying screen. The exposed film is then processed for 90 seconds using the conventional RP-XOMAT ™ process and the rapid KRA ™ process.
It is processed for 45 seconds. After treatment, the residual coloring level is 440 nm
It is measured by spectrophotometric measurement at (wavelength corresponding to absorption peak of condensation of sensitizing dye in gelatin), reciprocity law failure for exposure of 1/50 to 5 seconds, and spectral sensitivity of 300 to 500 nm. In this way it is confirmed that absorption of the optical brightener does not cause any sensitivity loss in the near UV. The pressure resistance is judged by using a pressure roll that simulates mechanical stress.

Example 1 In this example, the optical brightener was incorporated into the emulsion layer of a radiographic product. A colorless Estar ™ support, as described above,
Tabular grain silver bromide emulsion (21 mg Ag / dm ² , 2.85 mg / dm ² gelatin, 465 mg spectral sensitizing dye A per mole Ag) and gelatin overcoat (6.88 mg / dm ² ) simple A radiographic product in a digitized format was used. 0.6 mg / d
m ² optical brightener (Tinopal ™ or Phorwite
(Trademark)) before (IF) or immediately after (A) spectral sensitization.
F) It was placed in the emulsion layer. The product was processed on an automated processor for the RP-XOMAT ™ process and the KRA ™ process.

The obtained results are shown in FIGS. 1 and 2. In FIGS. 1 and 2, −1-Control (Check) represents a control product that does not contain any optical brightener in the emulsion layer: -2-Phorwite ™ IF (or 3-Tinopal ™) IF) stands for the product according to the invention in which an optical brightener is placed in the emulsion before sensitization, and -4-Phorwite ™ AF (or 5-Tinopal ™ AF) is fluorescent after sensitization. 1 represents a product according to the invention with a brightener in an emulsion.

1 and 2 show absorption spectra at 350 to 500 nm. The yellow residual dye due to the condensation of the sensitizing dye stagnant in gelatin corresponds to the major peak located at 440 nm. A less pronounced peak corresponding to the sensitizing dye monomer can be seen around 410 nm.
In the presence of the optical brightener according to the present invention, a decrease in the height of the peak at 440 nm was observed, the spectral change from 420 to 350 nm was due to the destruction of dye aggregates in gelatin and the optical brightener and gelatin. It is explained by the formation of species resulting from the interaction of the dyes with aggregates. 3 and 4 show
5 shows the optical density of residual color at 440 nm for the RP-XOMAT ™ process and the KRA ™ process.
In these figures, 1-control represents the control sample.

It will be appreciated that the method of incorporating the optical brightener (before or after the spectral sensitizing dye) is not critical. Rapid KRA ™ process, RP-XOMAT ™
The shortened development cycle compared to the process exacerbates the residual color in the absence of any optical brightener. K
Best results for both the RA ™ process and the RP-XOMAT ™ process are obtained when using Tinopal ™. This improvement is especially noticeable in the KRA ™ process.

In all cases, the optical brightener in the emulsion layer causes a loss of sensitivity of about 0.03 to 0.06 log H, where H represents the value of illuminance expressed in lux seconds. , On the other hand, another parameter, eg maximum concentration (D
_max ), minimum density (D _min ) and contrast are not actually affected. Reciprocity failure increases, but pressure resistance and fog of new or post-incubation products are unchanged. The present invention allows removal of up to 82% of residual color with the RP-XOMAT ™ process and up to 90% of residual color with the KRA ™ process without significantly compromising sensitometric properties. To

Example 2 In this example, the optical brightener was incorporated in a layer located between the emulsion layer and the support. This arrangement may be useful when it is difficult to put the optical brightener in the emulsion layer for practical reasons, or when interaction with another additive occurs. In this example, the 20 layers between the support and the emulsion layer are ordered in the following order.
mg / dm ² gelatin layer, tabular grain silver bromide emulsion (21 mg Ag /
A simplified format radiographic product was used, including dm ² , 32 mg / dm ² gel) and a gelatin overcoat (6.88 mg / dm ² ). 0.3, 0.6 and 1.2 mg respectively
/ dm ² in an amount of fluorescent brightener (Tinopal (TM) or Phor
wite ™).

5 and 6 show absorption spectra at 360 to 450 nm. It is observed that the two compounds can reduce residual coloration (peak reduction at 440 nm) and are more effective in the KRA ™ process. Figure 7
Indicates the optical density at 440 nm, which corresponds to residual coloration. Control standards represent controls. Tinopal at a concentration of 1.2 mg / dm ²
Best results are obtained with the ™.

In all cases, the presence of the optical brightener in the emulsion layer does not result in any loss of sensitivity, and other parameters such as D _max , D _min and contrast are practically unaffected. . Reciprocity failure, pressure resistance and fog of new or incubated products are unchanged. The present invention enables removal of up to 70% of residual color with the RP-XOMAT ™ process and up to 94% of residual color with the rapid KRA ™ process without compromising sensitometric properties. To

Example 3 (Comparative) In this example, amounts of 0.4 and 0.6 mg / dm ² , respectively, were used.
Phorwite ™ was placed in the gelatin overcoat. FIG. 8 shows a 350 for the RP-XOMAT ™ process.
Shows absorption spectrum at ~ 500 nm. Since only 15% of the residual color could be removed, it can be seen that the effect of the optical brightener is weak when placed in the overcoat. Sensitometric properties were not affected.

In conclusion, the best way to reduce residual coloration without any change in sensitometric properties is that the optical brightener in the gelatin layer of the photographic product placed between the emulsion layer and the support. It is obtained by putting.
In Example 2, at a concentration of 1.2 mg / m ² of Tinopal ™, the sensitometric properties were not affected, 90% of the residual color was removed by the rapid KRA ™ process, and 67% of the residual color was detected. % Are removed in the RP-XOMAT ™ process.

Examples 4-5 In these examples, standard format radiographic film is used. Layers of tabular grain silver bromide emulsion (32 mg) on each side of a Blue Estar ™ support in the following order:
/ dm ² gel, 21mg / dm ² Ag), gelatin middle layer (3.54mg)
/ dm ² gel), and gelatin overcoat (3.54mg)
/ dm ² gel) is coated. In Example 5, the film was a layer of gelatin (14 mg / dm ² placed between the emulsion layer and the support).
Gel) is also included. The film is hardened with bis (vinylsulfonylmethyl) ether and the amount of hardener is equal to 2.35% by weight of the total dry gelatin contained in the film. The emulsion is chemically and spectrally sensitized with spectral sensitizing dye A as in Example 1.

Example 4 In this example, 0.6 mg / dm ² of Tinopal ™ was placed in the emulsion after sensitization. A film sample is used as a conventional Kodak X-
Exposed to blue light with Omat ™ intensifying screen. The exposed film is then treated with RP-X as in the previous examples.
OMAT ™ process for 90 seconds, KRA ™ process for 45 seconds. The level of residual coloring was measured spectrophotometrically at 440 nm. A 70% reduction in optical density was observed for the RP-XOMAT ™ process at 440 nm when compared to the control without Tinopal ™, and KRA
An 86.5% reduction in optical density is observed with the ™ process. A significant loss of sensitivity, around 0.08 to 0.1 Log H, is also observed, and an increase in reciprocity law failure is also observed. Other parameters, such as D _max , D _min and contrast, are practically unaffected. The pressure resistance and fog of new or post-incubation products are unchanged.

Example 5 In this example, 1.2 mg / dm ² of Tinopal ™ was placed in a layer of gelatin placed between the support and emulsion layers after sensitization. Samples of the film were exposed and processed for 90 seconds using the RP-XOMAT ™ process and 45 seconds using the KRA ™ process as in the previous examples. The level of residual coloring was measured spectrophotometrically at 440 nm.
440nm compared to control without Tinopal ™
An 80% reduction in optical density is observed with the RP-XOMAT ™ process and a 93.5% reduction in optical density is observed with the KRA ™ process. No loss of sensitivity or increase in reciprocity law failure is observed. Another parameter, for example
D _max , D _min and contrast are not really affected. The pressure resistance and fog of new or post-incubation products are unchanged.

In conclusion, as in Examples 1 and 2,
The best way to reduce residual coloration without any change in sensitometric properties is obtained by including an optical brightener in the gelatin layer of the photographic product placed between the emulsion layer and the support. . In Example 5, 1.2 mg without affecting physical and sensitometric properties
With Tinopal ™ at a concentration of / m ² , up to 93.5% of the residual color is removed in the rapid KRA ™ process.

Further Specific Embodiments of the Invention 1. In gelatin, at least one light-sensitive silver halide tabular grain emulsion, and in radiographic images, an amount sufficient to cause residual yellow coloration by absorption of aggregates of residual dye in gelatin into said radiographic product. A radiographic product comprising a spectrally sensitizing dye in the visible spectrum, which is present and has an emission peak between 400 and 500 nm, and at least one photosensitive layer containing an optical brightening agent and a support, said fluorescent material comprising The whitening agent comprises: a) 4, having at least 3 anionic sulfo groups.
A derivative of 4'-diaminostilbenedisulfonic acid, b) present in at least one light sensitive layer of the radiographic product or in at least one gelatin layer located between the light sensitive layer and the support. A radiographic product characterized by: 2. The radiographic product of embodiment 1, wherein the optical brightener is in at least one light sensitive layer. 3. A radiographic product according to embodiment 1, wherein said optical brightener is in at least one layer of gelatin located between the photosensitive layer and the support.

4. The fluorescent whitening agent has the following formula

[Chemical 9] (In the above formula, R ₁ , R ₂ , R ₃ and R ₄ are independently the following groups,

Embedded imageHalogen, hydrogen, hydroxy, substituted or unsubstituted
Alkyl, substituted or unsubstituted aryl, substituted or
Selected from unsubstituted alkoxy and sulfo, R_FiveOh
And R₆Are each independently hydrogen, substituted or unsubstituted
Among alkyl and substituted or unsubstituted aryl
M is a cation that balances the ionic charge.
Provided that the compound is at least one solubilized
R is an anionic sulfo group₁, R ₂, R₃Or R_FourTo
Radiation image according to the specific aspect 1, represented by
True product.

5. The optical brightener is the following compound

[Chemical 11] A radiographic product according to embodiment 4, which is selected from among: 6. The radiographic product according to specific embodiment 1, wherein the amount of the optical brightener is 0.05 to ² mg / dm ² . 7. A radiographic product according to embodiment 6, wherein the amount of optical brightener is 0.5-1.5 mg / dm ² . 8. The radiographic product according to specific embodiment 1, wherein the spectral sensitizing dye is a cyanine dye.

9. The cyanine dye

[Chemical 12]

[Chemical 13]

Embedded image A radiographic product according to specific embodiment 8 selected from among: 10. At least 1 with maximum emission between 360 and 500 nm
A radiographic system comprising one X-ray intensifying screen and the radiographic product according to embodiment 1.

[Brief description of drawings]

FIG. 1 shows RP-X in which an optical brightener is present in the emulsion layer.
3 shows the absorption spectrum at 350-500 nm for the OMAT ™ process.

FIG. 2 shows KRA in which an optical brightener is present in the emulsion layer.
3 shows the absorption spectrum at 350-500 nm for the ™ process.

FIG. 3 shows RP-X in which an optical brightener is present in the emulsion layer.
Figure 4 shows the optical density of residual coloration at 440 nm for the OMAT ™ process.

FIG. 4 shows KRA in which an optical brightener is present in the emulsion layer.
Figure 4 shows the optical density of residual coloration at 440nm for the ™ process.

FIG. 5 shows the absorption spectrum at 350-500 nm for the RP-XOMAT ™ process, where the optical brightener is present in the gelatin layer between the support and the emulsion layer.

FIG. 6 shows the absorption spectrum at 350-500 nm for the KRA ™ process, where the optical brightener is present in the gelatin layer between the support and the emulsion layer.

FIG. 7 shows the optical density of residual coloration at 440 nm for the RP-XOMAT ™ process, where an optical brightener is present in the gelatin layer between the support and the emulsion layer.

FIG. 8 shows 3 for the RP-XOMAT ™ process, where an optical brightener is present in the gelatin overcoat.
The absorption spectrum at 50 to 500 nm is shown.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location G03C 5/17 G21K 4/00 A

Claims (1)

[Claims] 1. In gelatin, at least one light-sensitive silver halide tabular grain emulsion, and in a radiographic image, an amount sufficient to cause residual yellow coloration due to absorption of aggregates of residual dye in gelatin. A radiographic product comprising at least one photosensitive layer present in the radiographic product and having a visible spectrum spectral sensitizing dye having an emission peak between 400 and 500 nm, as well as an optical brightener and a support. Wherein the optical brightener comprises: a) having at least three anionic sulfo groups,
A derivative of 4'-diaminostilbenedisulfonic acid, b) present in at least one light sensitive layer of the radiographic product or in at least one gelatin layer located between the light sensitive layer and the support. A radiographic product characterized by: