Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
  • G03C1/0051—Tabular grain emulsions
  • G03C1/0053—Tabular grain emulsions with high content of silver chloride
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
  • G03C1/035—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein characterised by the crystal form or composition, e.g. mixed grain
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
  • G03C1/06—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein with non-macromolecular additives
  • G03C1/08—Sensitivity-increasing substances
  • G03C1/09—Noble metals or mercury; Salts or compounds thereof; Sulfur, selenium or tellurium, or compounds thereof, e.g. for chemical sensitising
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
  • G03C1/06—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein with non-macromolecular additives
  • G03C1/30—Hardeners
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C5/00—Photographic processes or agents therefor; Regeneration of such processing agents
  • G03C5/16—X-ray, infrared, or ultraviolet ray processes
  • G03C5/17—X-ray, infrared, or ultraviolet ray processes using screens to intensify X-ray images
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
  • G03C1/06—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein with non-macromolecular additives
  • G03C1/08—Sensitivity-increasing substances
  • G03C1/10—Organic substances
  • G03C1/12—Methine and polymethine dyes
  • G03C1/14—Methine and polymethine dyes with an odd number of CH groups
  • G03C1/18—Methine and polymethine dyes with an odd number of CH groups with three CH groups
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
  • G03C1/06—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein with non-macromolecular additives
  • G03C1/08—Sensitivity-increasing substances
  • G03C1/28—Sensitivity-increasing substances together with supersensitising substances
  • G03C1/29—Sensitivity-increasing substances together with supersensitising substances the supersensitising mixture being solely composed of dyes ; Combination of dyes, even if the supersensitising effect is not explicitly disclosed
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
  • G03C1/0051—Tabular grain emulsions
  • G03C2001/0055—Aspect ratio of tabular grains in general; High aspect ratio; Intermediate aspect ratio; Low aspect ratio
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
  • G03C1/035—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein characterised by the crystal form or composition, e.g. mixed grain
  • G03C2001/03517—Chloride content
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
  • G03C1/035—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein characterised by the crystal form or composition, e.g. mixed grain
  • G03C2001/03541—Cubic grains
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
  • G03C1/035—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein characterised by the crystal form or composition, e.g. mixed grain
  • G03C2001/03558—Iodide content
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
  • G03C1/035—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein characterised by the crystal form or composition, e.g. mixed grain
  • G03C2001/03594—Size of the grains
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
  • G03C1/06—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein with non-macromolecular additives
  • G03C1/08—Sensitivity-increasing substances
  • G03C1/09—Noble metals or mercury; Salts or compounds thereof; Sulfur, selenium or tellurium, or compounds thereof, e.g. for chemical sensitising
  • G03C2001/095—Disulfide or dichalcogenide compound
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
  • G03C1/06—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein with non-macromolecular additives
  • G03C1/08—Sensitivity-increasing substances
  • G03C1/09—Noble metals or mercury; Salts or compounds thereof; Sulfur, selenium or tellurium, or compounds thereof, e.g. for chemical sensitising
  • G03C2001/096—Sulphur sensitiser
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
  • G03C1/06—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein with non-macromolecular additives
  • G03C1/08—Sensitivity-increasing substances
  • G03C1/09—Noble metals or mercury; Salts or compounds thereof; Sulfur, selenium or tellurium, or compounds thereof, e.g. for chemical sensitising
  • G03C2001/097—Selenium
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C5/00—Photographic processes or agents therefor; Regeneration of such processing agents
  • G03C5/26—Processes using silver-salt-containing photosensitive materials or agents therefor
  • G03C5/29—Development processes or agents therefor
  • G03C5/30—Developers
  • G03C2005/3007—Ascorbic acid
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C2200/00—Details
  • G03C2200/03—111 crystal face
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C5/00—Photographic processes or agents therefor; Regeneration of such processing agents
  • G03C5/26—Processes using silver-salt-containing photosensitive materials or agents therefor
  • G03C5/29—Development processes or agents therefor
  • G03C5/30—Developers

Definitions

• the present invention relates to a system for radiological image formation by means of a suitable film material in operative association with an intensifying screen and to a method for image formation.
• preferred low coating amounts of silver halide in the silver halide material therefore may lay burden on the preferred high covering power of the developed crystals, the more if use is made of cubic crystals if compared with tabular grains.
• tabular grains it has been disclosed in US-P 4,414,340 that high hardening levels of silver halide materials coated from such grains are maintaining covering power of developed grains at the preferred level.
• EP-A 0 709 730 and in EP-Application No. 96203728, filed December 30, 1996 it has further been shown that in a developer having an adapted chemical composition, covering power is advantageously increased.
• Strongly hardened silver halide photographic materials moreover provide the advantage to use concentrated developing and fixing solutions free from hardening agents as has been set forth e.g. in US-A 5,296,342, which again is in favour of ecology.
• "400"-speed high speed
• an image-forming system for radiological imaging consisting of an intensifying screen comprising on a support at least one layer of a green-light emitting phosphor and in operative association therewith a prehardened light-sensitive photographic silver halide film material, comprising a support and on both sides thereof one or more hydrophilic colloid layers, said layers being hardened to such an extent that their swelling degree is reduced to less than 200 % after immersing said material for 2 minutes in demineralized water of 35 °C; comprising in at least one of said hydrophilic layers chemically ripened, monodisperse cubic silver chloroiodide grains having a mean crystal diameter of from 0.40 ⁇ m up to 0.65 ⁇ m or chemically ripened ⁇ 111 ⁇ tabular silver chloroiodide grains having an aspect ratio of from 5 to 20 and a tabularity from 20 to 200; wherein said grains have been spectrally sensitized for the wavelength range between 520 and 580 nm, have a maximum
• said silver chloroiodide grains have been chemically sensitized with one or more selenide compound(s) generating silver selenide in an emulsion comprising said grains at a temperature of from 45°C up to 70°C at an electrical potential difference between a silver electrode and a saturated silver/silver chloride reference electrode of from 100 up to 200 mV.
• a light-sensitive emulsion layer from the material of the image-forming system comprises relatively small cubic silver chloroiodide crystals with an average grain size of from 0.40 ⁇ m up to 0.65 ⁇ m and a monodisperse grain distribution or comprises ⁇ 111 ⁇ tabular silver chloroiodide grains with an aspect ratio of from 5 to 20 and a tabularity (defined as a ratio between aspect ratio and crystal thickness) of from 20 to 200; a sufficient speed is attained without deterioration of image tone, in that no shift to brown coloured silver after development is observed for both types of crystal habit defined hereinbefore.
• unstable selenium sensitizers are isoselenocyanates (e.g., aliphatic isoselencyanates such as allylisoselenosyanate), selenoureas, selenoketones, selenoamides, selenocarboxylic acids (e.g. 2-selenopropionic acid, and 2-selenobutyric acid) selenoesters, diacylselenides (e.g. bis(3-chloro-2,6-dimethoxybenzoyl)selenide), selenophosphates, phosphineselenides as triphenylphosphorselenide and colloidal elemental selenium.
• isoselenocyanates e.g., aliphatic isoselencyanates such as allylisoselenosyanate
• selenoureas e.g., selenoketones, selenoamides, sele
• unstable selenium compounds should generate silver selenide in an emulsion comprising said grains at a temperature of from 45°C up to 70°C and at an electrical potential difference between a silver electrode and a saturated silver/silver chloride reference electrode of from 100 up to 200 mV only. It could e.g. be proved (see also Examples) that triphenylphosphorselenide was not a suitable chemical sensitizer for silver chloroiodide emulsion crystals coated in materials used in the image-forming system of the present invention.
• selenium compounds generating silver selenide in the prescribed circumstances are preferably compounds selected from the group consisting of substituted selenoureum, substituted triphenylphosphine selenide and substituted and unsubstituted triphenylorthophosphate selenide.
• One or more of these chemical sensitizers generating silver selenide only in the well described circumstances of temperature and potential is thus preferred in the chemical sensitization method applied to the essentially cubic or ⁇ 111 ⁇ tabular silver chloroiodide crystals coated in one or more emulsions in light-sensitive hydrophilic layers of radiographic materials of screen-film image-forming systems according to the present invention.
• said monodisperse cubic grains and/or ⁇ 111 ⁇ tabular silver chloroiodide grains should further be chemically ripened with one or more sulphur and/or gold compounds.
• Patent literature with respect to the use of selenium sensitizers for chemical ripening of silver chloroiodide grains can be found in EP-A's 0 443 453, 0 454 278; 0 458 278; 0 513 748; 0 590 593; 0 661 589 and 0 718 674 and in US-A's 4,810,626; 5,306,613 and 5,348,850, wherein said selenium sensitizers are normally used together with other sensitizers as at least gold and optionally sulphur.
• Especially useful labile compounds providing sulphur are the more preferred compounds selected from the group consisting of tetramethyl-thiodithioacetic acid diamide (which is preferably used in the context of the present invention), dimethylamino-dithiomercaptane, thiosulphate and thiosulphonate compounds.
• Other useful compounds are those as described e.g. in "Chimie et Physique Photographique" by P. Glafkides, in “Photo-graphic Emulsion Chemistry” by G.F. Duffin, in “Making and Coating Photographic Emulsion” by V.L. Zelikman et al, and in "Die Grund-lagen der Photographischen Sawe mit Silberhalogeniden” edited by H. Frieser and published by Akademische Verlagsgesellschaft (1968).
• chemical sensitization can be carried out by effecting the ripening in the presence of small amounts of compounds containing sulphur as e.g. thiosulphate, thiocyanate, thioureas; sulphites, mercapto compounds, rhodamines etc.., wherein combinations of gold-sulphur ripeners together with the required selenium sensitizers are the most preferred.
• sulphur e.g. thiosulphate, thiocyanate, thioureas
• sulphites mercapto compounds
• rhodamines etc.. mercapto compounds
• tin compounds as described in GB-A 789,823, amines, hydrazine derivatives, formamidine-sulphinic acids, and silane compounds may be used, although care should be taken in order to prevent the emulsion from fog formation in an uncontrollable way.
• Normal amounts of selenium compounds are in the range from 1 x 10 -5 to 1 x 10 -7 moles per mole of silver, whereas normal amounts of gold compounds (as gold chloride or gold thiocyanate) are in the range from 1 x 10 -5 to 2.5 x 10 -5 moles per mole of silver.
• the precipitation conditions thereof can be chosen such that said emulsions are emulsions having an essentially cubic crystal habit.
• the precipitation of such cubic crystals can be principally performed by one double jet step ; alternatively it may consist of a sequence of consecutive double jet steps comprising a nucleation step and at least one growth step.
• the different steps of the precipitation can be alternated by physical ripening steps. In order to get reproducible emulsion grain distributions said different steps proceed under controlled conditions of pH, pAg, temperature, stirring velocity and addition rates, wherein said addition rates may be held constant or may be increased as precipitation proceeds in order to reduce the total time thereof. However care should be taken in order to avoid renucleation.
• a crystal growth accelerator can be added, in favour of crystal growth, further avoiding renucleation.
• growth accelerators are thioether compounds as e.g. methionine , 1,8-dihydroxy-3,6-dithio-octane,etc., or polyoxyalkylenes although care should be taken with respect to fog formation.
• Crystals having an essentially cubic habit, dispersed as an emulsion coated in one or more hydrophilic layers of the material used in the image-forming system of the present invention have an average crystal diameter of from 0.40 ⁇ m up to 0.65 ⁇ m, with a high degree of homogeneity: a variation coefficient on the grain size distribution of less than 0.25 and, more preferred, between 0.10 and 0.20 contributes to the desired sensitometry and image quality. Mixtures of emulsions having grains with homogeneous or monodisperse grain size distributions may be useful.
• Tabular silver halide grains having a ⁇ 111 ⁇ crystal habit have been promoted since 1982 as being applicable in photographic materials for practical use and are defined as crystals possessing two parallel faces with a ratio between the diameter of a circle having the same area as these faces (the so-called equivalent circular diameter or E.C.D.), and the thickness, being the distance between the two major faces, equal to at least 2.
• ⁇ 111 ⁇ tabular silver chloroiodide grains have aspect ratios of from 5 to 20 and tabularities of from 20 to 200. The tabularity of such tabular crystals is therein defined as the ratio between average aspect ratio and grain thickness or between E.C.D. and thickness square.
• Compounds that are useful as crystal habit modifier for tabular crystals rich in silver chloride besides the most frequently used adenine include substances disclosed in EP-A's 0 481 133 and 0 532 801 and in US-A's 5,176,991; 5,176,992; 5,178,997; 5,178,998; 5,183,732; 5,185,239; 5,217,858; 5,221,602; 5,252,452; 5,264,337; 5,272,052; 5,298,385; 5,298,387; 5,298,388; 5,399,478; 5,405,738; 5,411,852 and 5,418,125.
• Tabular silver halide grains rich in chloride, bounded by ⁇ 111 ⁇ major faces and/or the preparation method thereof and/or materials in which said grains are incorporated have also been described in e.g. US-A's 4,399,215; 4,400,463; 4,804,621; 5,061,617; 5,275,930; 5,286,621; 5,292,632; 5,310,644; 5,320,938; 5,356,764; in the published EP-A's 0 503 700, 0 533 189, 0 647 877 and 0 678 772.
• Iodide ions may be provided by using aqueous solutions of inorganic salts thereof as e.g.
• Iodide ions can however also be provided by organic compounds releasing iodide ions as has e.g. been described in EP-A's 0 561 415, 0 563 701, 0 563 708, 0 649 052 and 0 651 284 and in WO 96/13759.
• iodide ions provided by organic agents releasing iodide ions are preferred such as mono iodide acetic acid, mono iodide propionic acid, mono iodide ethanol and even hydrogels containing iodide ions, capable to generate iodide ions.
• Generation of iodide ions is triggered by changing the pH value in the reaction vessel during or, preferably, after addition of the said organic agent releasing iodide ions.
• Grain size distributions of silver chloroiodide crystals over the light-sensitive emulsion are homogeneous or monodisperse by controlling the precipitation methods used.
• Metal ions or metal ion complexes also called dopants commonly added in low amounts to the silver chloroiodide crystals in whatever a stage of the preparation, generally have little influence on crystal distributions in the emulsions but may be added to cause advantageous effects with respect to reciprocity, pressure sensitization, etc..
• heterogeneous distributions can be obtained and may even be more advantageous e.g. from the point of view of exposure latitude but in order to obtain the same effect of e.g. an increasing exposure latitude is reached by making mixtures of different homogeneous emulsions having very low variation coefficients e.g. in the range from 0.05 to 0.15.
• This may lead to even more advantageous sensitometric characteristics (e.g. increased contrast) or image quality (e.g. granularity and/or sharpness) as has been illustrated e.g. in US-A 4,446,228 and in EP-A 0 555 897.
• Boundary values of aspect ratios and tabularities of ⁇ 111 ⁇ tabular silver chloroiodide grains mentioned hereinbefore are related with the fact that particularly the requirement of high sensitivity and the particular advantages of spectrally sensitized tabular grains should be combined: the presence of iodide ions at the surface of silver chloroiodide tabular crystals already set forth hereinbefore is not only preferred from the viewpoint of crystal habit stability but particularly preferred as upon spectral sensitization an improved adsorption of the spectral sensitizer and an improved light absorption is obtained and as the quantum efficiency detected in the photochemical processes is increased.
• Spectral sensitizers are preferably added in a total amount needed to reach an optimal coverage degree which, especially with a larger specific surface of tabular grains as mentioned hereinbefore may differ, from amounts added to cubic grains, with a factor of about 2 or even 3.
• silver chloroiodide grains whether having an (essentially) cubic or a ⁇ 111 ⁇ tabular habit are spectrally sensitized with compounds selected from the group consisting of benzimidazoles, benzoxazoles, and a combination thereof. Especially a combination of benzimidazolo- and benzoxazolo-carbocyanines is preferred.
• An example of a useful spectral sensitizer according to the general formula given above is anhydro-5,5'-dichloro-3,3'-bis(n-sulphobutyl)-9-ethyloxacarbocyanine hydroxide or anhydro-5,5'-di-chloro-3,3'-bis(n-sulphopropyl)-9-ethyloxacarbocyanine hydroxide.
• a suitable mixture of spectral sensitizers that is applied in the context of the present invention is anhydro-5,5'-dichloro-3,3'-bis-(n-sulphobutyl)-9-ethyl oxacarbocyanine hydroxide or anhydro-5,5'-dichloro-3,3'-bis(n-sulphopropyl)-9-ethyl-oxacarbocyanine hydroxide together with anhydro-5,5'-dicyano-1,1'-diethyl-3,3'-di(2-acetoxyethyl)ethyl-imidacarbocyanine bromide.
• spectral sensitization In classical emulsion preparation spectral sensitization traditionally follows the completion of chemical sensitization. However in connection with tabular grains, as already set forth hereinbefore, it is highly contemplated that spectral sensitization can occur simultaneously with or even precede completely the chemical sensitization step. It can be advantageous therefore to add an amount of a spectral sensitizing dye to the emulsion crystals just before cooling of the dispersion at the end of the growth step, but in principle the addition of the said dye may be performed at any stage of the precipitation, during or after redispersing or before, during or after chemical ripening. The addition can further be performed in one or more portions. In US-A 5,286,621 it has e.g. been shown that spectral sensitizer is added in amounts ranging from 10 -5 to 5 x 10 -3 moles per mole of silver halide as a whole after completion of the precipitation or in several fractions during and after the said precipitation.
• Light-sensitive cubic silver chloroiodide grains may be spectrally sensitized with methine dyes such as those described by F.M. Hamer in "The Cyanine Dyes and Related Compounds", 1964, John Wiley & Sons.
• Dyes that may be used for the purpose of spectral sensitization include cyanine dyes, merocyanine dyes, complex cyanine dyes, complex merocyanine dyes, homopolar cyanine dyes, hemicyanine dyes, styryl dyes and hemioxonol dyes.
• Cubic crystals rich in chloride may also be spectrally sensitized with one or more spectral sensitizers, chosen not only in favour of sensitometry but also in favour of decolourizing properties.
• Specific sensitizations with green-sensitizing imida-oxacarbo-cyanines have e.g. been described in US-A's 4,701,405; 5,219,723; 5,376,523; 5,462,850 and JP-B 95-013732.
• Spectral sensitizers having asymmetrical heterocycles may be useful with respect to improvements in residual colouration after processing.
• gelatin An important factor influencing growth of silver nuclei in the preparation of silver chloroiodide grains is the choice of and the amount of protective colloid present in the reaction vessel or added simultaneously with one of the solutions added thereto during nucleation and further, eventually, after nucleation, during physical ripening before and/or during growth of the nuclei formed.
• the most well-known and practically used hydrophilic colloidal binder during precipitation of silver chloroiodide crystals is gelatin.
• the preparation of conventional lime-treated or acid treated gelatin has been described in e.g. "The Science and Technology of Gelatin", edited by A.G. Ward and A. Courts, Academic Press 1977, page 295 and next pages.
• the gelatin can also be enzyme-treated as described in Bull. Soc. Sci. Phot.
• Gelatin may, however, be replaced in part or integrally by synthetic, semi-synthetic, or natural polymers.
• Synthetic substitutes for gelatin are e.g. polyvinyl alcohol, poly-N-vinyl pyrrolidone, polyvinyl imidazole, polyvinyl pyrazole, polyacrylamide, polyacrylic acid, and derivatives thereof, in particular copolymers thereof.
• Natural substitutes for gelatin are e.g. other proteins such as zein, albumin and casein, cellulose, saccharides, starch, and alginates.
• the semi-synthetic substitutes for gelatin are modified natural products e.g.
• gelatin derivatives obtained by conversion of gelatin with alkylating or acylating agents, by grafting of polymerizable monomers on gelatin or prehardened gelatins with blocked functional groups as a consequence of this prehardening treatment, cellulose derivatives such as hydroxyalkyl cellulose, carboxymethyl cellulose, phthaloyl cellulose, and cellulose sulphates and even potato starch.
• Part of gelatin may further be replaced with a synthetic or natural high-molecular material.
• An interesting substitute for gelatin may be silica as has been described in the published EP-A's 0 392 092, 0 517 961, 0 528 476, 0 649 051 and 0 704 749.
• EP-A 0 528 476 a method of preparing a silver halide light-sensitive photographic material incorporating layers of silver halide precipitated in colloidal silica serving as a protective colloid is given.
• the silver halides are prepared in colloidal silica, leading to emulsion crystals that are stable at the end of the precipitation, without however having a predictable mean crystal diameter and crystal size distribution.
• silica sols are required as colloidal binder commercially available such as the "Syton” silica sols (a trademarked product of Monsanto Inorganic Chemicals Div.), the "Ludex” silica sols (a trademarked product of du Pont de Nemours & Co., Inc.), the "Nalco” and “Nalcoag” silica sols (trademarked products of Nalco Chemical Co), the "Snowtex” silica sols of Nissan Kagaku K.K. and the "Kieselsol, Types 100, 200, 300, 500 and 600" (trademarked products of Bayer AG).
• Particle sizes of the silica sol particles are in the range from 3 nm to 30 ⁇ m.
• the smaller particles in the range from 3 nm to 0.3 ⁇ m, and still more preferable from 3 nm up to 7 nm are preferred as the covering degree that can be achieved will be higher and as the protective action of the colloidal silica will be more effective.
• the emulsion mixture is normally cooled to about 40°C, before or after adding a flocculate being a polymeric compound as e.g. polystyrene sulphonic acid, providing as a anionic polymer a behaviour depending on pH.
• a flocculate being a polymeric compound as e.g. polystyrene sulphonic acid, providing as a anionic polymer a behaviour depending on pH.
• a flocculate being a polymeric compound as e.g. polystyrene sulphonic acid, providing as a anionic polymer a behaviour depending on pH.
• a flocculate being a polymeric compound as e.g. polystyrene sulphonic acid, providing as a anionic polymer a behaviour depending on pH.
• the pH of the said dispersing medium is adjusted with an acid to a value in order to get a qualitatively good flocculate.
• Said flocculate may become decanted and
• adenine to an allowable residual amount preferably at most 0.3 mg/g of gelatin
• an ultrafiltration washing procedure as disclosed e.g. in Research Disclosure, Vol. 102, Oct. 1972, Item 10208, Research Disclosure Vol. 131, March, Item 13122 and Mignot US-A 4,334,012.
• Said ultrafiltration technique may be applied on-line during the whole precipitation, in order to reduce the increasing amount of water, thus avoiding dilution of the reaction vessel and increasing amounts of soluble salts like the mainly occurring potassium nitrate. Examples thereof have been described e.g. in EP-A 0 577 886.
• suitable as a binder material can be added at a later stage of the emulsion preparation as e.g. after washing, in order to establish optimal coating conditions and/or to establish the required thickness of the coated emulsion layer.
• a gelatin to silver halide ratio silver halide being expressed as an equivalent amount of silver nitrate, ranging from 0.3 to 1.0 is then obtained.
• Another binder may also be added instead of or in addition to gelatin.
• Useful vehicles, vehicle extenders, vehicle-like addenda and vehicle related addenda have been described e.g. in Research Disclosure N° 38957 (1996), Chapter II.
• any thickening agent may be used in order to regulate the viscosity of the coating solution, provided that they do not particularly affect the photographic characteristics of the silver chloroiodide emulsion in the coated photographic material.
• Preferred thickening agents include aqueous polymers such as polystyrene sulphonic acid, dextran, sulphuric acid esters, polysaccharides, polymers having a sulphonic acid group, a carboxylic acid group or a phosphoric acid group as well as colloidal silica.
• Polymeric thickeners well-known from the literature resulting in thickening of the coating solution may even be used in combination with colloidal silica. Patents concerning thickening agents are e.g.
• hydrophilic colloidal layer compositions on a support by slide-hopper or curtain-coating techniques, wherein said compositions have gelatin in low amounts in order to provide a ratio by weight of gelatin to silver halide expressed as an equivalent amount of silver nitrate in the range from 0.05 to 0.4
• thickening agents composed of synthetic clay and anionic macromolecular polyelectrolytes wherein said synthetic clay is present in an amount of at least 85 % by weight versus the total amount of thickening agents are recommended as has been disclosed in EP-A 0 813 105.
• Photographic material having thin emulsion layers e.g. layers with a layer thickness of not more than 6 ⁇ m, containing at most 6 g of gelatin, more preferably from 2 g/m 2 up to 6 g/m 2 of gelatin, and even more preferably to about 3.5 g/m 2 offer the advantage that besides rapid processing applicability and the rapid drying of the wet processed material an improvement in sharpness is observed.
• drying characteristics in the processor are mainly determined by the water absorption of the hydrophilic layers of the photographic material, and since the water absorption is directly proportional to the gelatin content of the layers and inversely proportional to the amount of hardener, added to the layer, its composition is optimized with a low gelatin content and a high hardening degree in order to allow hardener free processing within a total processing time cycle of from 30 to at most 60 seconds dry-to-dry, and, more preferably, at most 50 seconds.
• the layer binder In order to reach a high hardening degree the layer binder should of course dispose of an acceptably high number of functional groups, which by reaction with an appropriate hardening agent can provide a sufficiently resistant layer.
• functional groups are especially the amino groups, but also carboxylic groups, hydroxy groups, and active methylene groups.
• Hardeners may be added to the antistress layer, covering one or more light-sensitive silver halide emulsion layers rich in chloride before or during the coating procedure, or to one or more of the said emulsion layers.
• the binders of the photographic element can be hardened with appropriate hardening agents such as those of the epoxide type, those of the ethylenimine type, those of the vinylsulfone type e.g. 1,3-vinylsulphonyl-2-propanol, chromium salts e.g. chromium acetate and chromium alum, aldehydes e.g. formaldehyde, glyoxal, and glutaraldehyde, N-methylol compounds e.g. dimethylolurea and methyloldimethylhydantoin, dioxan derivatives e.g.
• appropriate hardening agents such as those of the epoxide type, those of the ethylenimine type, those of the vinylsulfone type e.g. 1,3-vinylsulphonyl-2-propanol, chromium salts e.g. chromium acetate and
• 2,3-dihydroxy-dioxan active vinyl compounds e.g. 1,3,5-triacryloyl-hexa-hydro-s-triazine, active halogen compounds e.g. 2,4-dichloro-6-hydroxy-s-triazine, and mucohalogenic acids e.g. mucochloric acid and mucophenoxy-chloric acid.
• These hardeners can be used alone or in combination.
• the binders can also be hardened with fast-reacting hardeners such as carbamoylpyridinium salts.
• Formaldehyde and phloroglucinol can e.g. be added respectively to the protective layer(s) and to the emulsion layer(s).
• Preferred hardening agents in the context of the present invention however are bis-(vinyl-sulphonyl)-methane (BVSME) and ethylene bis-(vinylsulphone).
• Materials used in the image-forming system according to the present invention commonly have a hardening degree corresponding with a swelling degree of the layers of the material of less than 200 % and even more preferably of not more than 150 % as can be measured from thickness ratios of the layers of the material before and after immersion in demineralized water of 25°C for 3 minutes.
• sensitometric properties e.g. sensitivity (also called speed), gradation (also called contrast and specified in the toe, the linear part and/or the shoulder of the characteristic curve), fog and maximum density in preferred rapid processing conditions for the materials coated from silver chloroiodide emulsions used in the image-forming system according to the present invention.
• sensitivity also called speed
• gradation also called contrast and specified in the toe, the linear part and/or the shoulder of the characteristic curve
• fog and maximum density in preferred rapid processing conditions for the materials coated from silver chloroiodide emulsions used in the image-forming system according to the present invention.
• the photographic element may further comprise various kinds of coating physical property modifying addenda as described in RD N° 38957 (1996), Chapter IX, wherein coating aids, plasticizers and lubricants, antistats and matting agents have been described.
• Development acceleration can be accomplished by incorporating in emulsion layer(s) or adjacent layers various compounds, preferably polyalkylene derivatives having a molecular weight of at least 400 such as those described in e.g. US-A's 3,038,805; 4,038,075 and 4,292,400 as well as in EP-A's 0 634 688 and 0 674 215.
• various compounds preferably polyalkylene derivatives having a molecular weight of at least 400 such as those described in e.g. US-A's 3,038,805; 4,038,075 and 4,292,400 as well as in EP-A's 0 634 688 and 0 674 215.
• the photographic element may further comprise various other additives such as e.g. compounds improving the dimensional stability of the photographic element, ultraviolet absorbers and spacing agents.
• Suitable additives for improving the dimensional stability of the photographic element are e.g. dispersions of a water-soluble or hardly soluble synthetic polymer e.g.
• Suitable UV-absorbers are e.g. aryl-substituted benzotriazole compounds as described in US-A 3,533,794, 4-thiazolidone compounds as described in US-A 3,314,794 and 3,352,681, benzophenone compounds as described in JP-A 56-2784, cinnamic ester compounds as described in US-A's 3,705,805 and 3,707,375, butadiene compounds as described in US-A 4,045,229, and benzoxazole compounds as described in US-A 3,700,455 and those described in RD N° 38957 (1996), Chapter VI, wherein also suitable optical brighteners are mentioned.
• Spacing agents may be present of which, in general, the average particle size is comprised between 0.2 and 10 ⁇ m. Spacing agents can be soluble or insoluble in alkali. Alkali-insoluble spacing agents usually remain permanently in the photographic element, whereas alkali-soluble spacing agents usually are removed therefrom in an alkaline processing bath. Suitable spacing agents can be made e.g. of polymethyl methacrylate, of copolymers of acrylic acid and methyl methacrylate, and of hydroxypropylmethyl cellulose hexahydrophthalate. Other suitable spacing agents have been described in US-A 4,614,708.
• a material has a single or a duplitized emulsion layer coated on one (single-side coated) or both sides (double-side coated) of the support respectively.
• This invention is related with double-side coated materials comprising silver chloroiodide emulsion grains as discussed hereinbefore.
• a mixture of two or more emulsions having silver chloroiodide crystals with the same or different crystal sizes, the same or a different crystal habit, a different or the same chemical ripening treatment and/or a different or the same coverage degree with one or more spectral sensitizers being different from each other or the same as those described hereinbefore, may be added to at least one light-sensitive emulsion layer, provided that at least one emulsion has crystals ripened with one or more selenium compounds generating silver selenide in an emulsion comprising said grains at a temperature of from 45°C up to 70°C at an electrical potential difference between a silver electrode and a saturated calomel reference electrode of from 100 up to 200 mV.
• Double-side coated materials wherein said crystals can advantageously be used have e.g. been described in US-A 5,397,687; in EP-A 0 678 772 and in EP-A's 0 754 972 and 0 754 971.
• said monodisperse cubic and/or ⁇ 111 ⁇ tabular silver chloroiodide grains have further been chemically ripened in the presence of one or more sulphur and/or gold compounds.
• said sulphur compound(s) is(are) one or more compound(s) selected from the group consisting of tetramethylthio-dithiocarboxylic acid diamide, dimethylamino-dithiomercaptane, thiosulphate and thiosulphonate compounds.
• emulsion layer is coated onto at least one side of the double-side coated support the same or different emulsions or emulsion mixtures may be present in the different layers. If the same emulsion or emulsion mixture is present in different emulsion layers distinct amounts of (same or different) spectral sensitizer may have been added during chemical riping and/or preparation for coating in order to get a broader exposure latitude for the material according to the image-forming method of the present invention and less sensitometric fluctuations in the processing of the hardcopy material.
• spectral sensitizer If more than one spectral sensitizer is used, wherein at least one of them is absorbing to a differing wavelength region, it is preferred to add them to different layers too, and still more preferred to add them to layers situated at different sides of the support as wandering of spectral sensitizers may form a problem.
• Such arrangement has e.g. been described in e.g. US-A's 4,978,599 and 5,380,636.
• the photographic material may contain several light-insensitive layers at the side of the support carrying said light-sensitive emulsion layer(s), e.g. a protective antistress layer which can be split up into two layers, one of them being an underlying interlayer or an outermost afterlayer coated or sprayed on top of the "basic" protective antistress layer, one or more subbing layers, one or more intermediate layers e.g. filter layers and even an afterlayer containing e.g. hardening agent(s), antistatic agent(s), filter dyes for safety-light purposes etc.
• a protective antistress layer which can be split up into two layers, one of them being an underlying interlayer or an outermost afterlayer coated or sprayed on top of the "basic" protective antistress layer
• subbing layers one or more intermediate layers e.g. filter layers and even an afterlayer containing e.g. hardening agent(s), antistatic agent(s), filter dyes for safety-light purposes etc.
• Protective antistress layers preferably contain coating aids and coating physical property modifying addenda mentioned in RD No.38957, published September 1996, Chapter IX. Antistatic properties are especially preferred in order to prevent blackening after processing in form of sparks, etc. due to abrupt decharging of electrostatic charges during production and/or handling before exposure and/or processing. It is highly preferred to add antistatic agents to the protective antistress layer or to an afterlayer coated thereupon as has been described e.g. in EP-A's 0 534 006, 0 644 454 and 0 644 456 and in US-A's 4,670,374 and 4,670,376.
• Abrasion resistance of these outermost layers may be improved as described in US-A's 4,766,059 and 4,820,615.
• Spraycoating of afterlayers has been disclosed e.g. in US-A 5,443,640.
• Non-imagewise blackening occurring as a result of pressure sensitivity of silver halide grains rich in chloride is lowered in the present invention due to the presence of iodide ions at the grain surface of tabular as well as cubic crystals.
• Measures in order to further suppress pressure sensitivity may be coating of enhanced amounts of binder as e.g. gelatin.
• silver chloroiodide prepared in silica may offer an alternative as has been disclosed e.g.
• the support of the photographic materials comprising silver halide emulsions with silver chloroiodide crystals used for X-ray imaging may be a transparent resin, preferably a blue coloured polyester support like polyethylene terephthalate.
• the thickness of such organic resin film is preferably about 175 ⁇ m.
• Other hydrophobic resin supports are well known to those skilled in the art and are made e.g. of polystyrene, polyvinyl chloride, polycarbonate and polyethylene naphthalate.
• the support is further provided with a substrate layer at both sides to have good adhesion properties between the adjacent layers and said support: one or more subbing layers known to those skilled in the art for adhering thereto a hydrophilic colloid layer may be present.
• Suitable subbing layers for polyethylene terephthalate supports are described e.g. in US-A's 3,397,988, 3,649,336, 4,123,278 and 4,478,907.
• a preferred layer arrangement wherein a subbing layer composition comprising as a latex copolymer vinylidene chloride, methylacrylate and itaconic acid has been covered with hydrophilic layers being at least one gelatinous dye containing layer comprising one or more dyes, at least one silver halide emulsion layer, at least one protective antistress layer, and optionally an afterlayer has been described in EP-A 0 752 617.
• said hydrophilic layers have a swelling ratio of not more than 200 % and in said hydrophilic layers are coated simultaneously by the slide-hopper coating or by the slide-hopper curtain coating technique. Further information on suitable supports can be found in RD No. 38957, Chapter XV, published September 1996.
• penetrating radiation which is high energy radiation belonging to the class of X-rays, ⁇ -rays and high energy elementary particle radiation, e.g. ⁇ -rays, electron beam or neutron radiation.
• penetrating radiation For the conversion of penetrating radiation into visible light and/or ultraviolet radiation luminescent substances are used called phosphors.
• an X-ray radiograph is obtained by X-rays transmitted imagewise through an object and converted into light of corresponding intensity in a so-called intensifying screen (X-ray conversion screen) wherein phosphor particles absorb the transmitted X-rays and convert them into visible light and/or ultraviolet radiation whereto a photographic film is made more sensitive: it is clear that spectral sensitizers are chosen as a function of and in order to absorb light of about the same wavelength range as the one emitted by luminescent phosphors coated in phosphor layers of intensifying screens brought into contact with the double-side coated film materials during X-ray exposure.
• intensifying screen X-ray conversion screen
• silver chloroiodide crystals are spectrally sensitized in the green-wavelength range of the spectrum as e.g. described in GB 1 489 398; in US-A's 4,431,922 and 4,710,637. More particlarly silver chloroiodide crystals are spectrally sensitized between 520 and 580 nm, and have a maximum absorption between 540 and 550 nm in order to absorb light emitted from X-ray exposed screens coated from preferred green-light emitting gadolinium oxisulphide phosphors.
• Such phosphors suitable for use in a conventional radiographic system must have a high prompt emission on X-ray irradiation and low afterglow in favour of image-sharpness.
• terbium activated gadolinium oxisulphide phosphor crystals are particularly suitable for use in the image-forming system according to the present invention.
• Screen-film systems wherein green-light emitting screens are used in contact with green sensitized silver halide films have been described e.g. in EP-A 0 678 772.
• an X-ray radiation source is used having an energy of from 60 to 150 kVp, e.g. 80 kVp for the detection of bone.
• the type of binder and the high volume ratio of phosphor to binder it is possible to obtain thin phosphor coatings offering not only high resolution but also high sensitivity without the need for increasing the packing density by compressing so as to reduce the voids as defined in EP-A 0 393 662 to a value of not less than 70%. Moreover the phosphor layer retains high protection against mechanical damage and thus high ease of manipulation.
• a practically useful binder medium for the phosphor particles has further been disclosed in WO94/000530.
• the binding medium substantially consists of one or more hydrogenated styrene-diene block copolymers, having a saturated rubber block, as rubbery and/or elastomeric polymers.
• the polymer can be represented by the formula A-B-A (tri-block) or by the formula A-B (di-block), wherein A represents styrene and B represents the hydrogenated diene block e.g. ethylene-butylene or ethylene-propylene.
• Screen/film combinations may be symmetric or asymmetric: this means that screens differing in speed and/or radiation emitted therefrom are differing and/or that there is a difference in speed and/or contrast and/or spectral sensitivity at both sides of the film support.
• a method of image formation offered as described in the present invention comprises the step of processing said film material after exposure with light emitted by a green-light emitting phosphor of an intensifying screen after conversion of X-rays having an energy from 60 to 150 kVp, wherein said step of processing proceeds in an automatic processor.
• the image-forming method of the present invention further comprises the step of processing said film material used in the image-forming system described hereinbefore, wherein said processing comprises the steps of developing in a developing solution comprising (iso)ascorbic acid, l-ascorbic acid, reductic acid, salts and/or derivatives thereof; fixing in a fixer solution free from aluminum salts; rinsing and drying.
• replenishing said developing and fixer solution proceeds with amounts of replenisher in the range from 100 up to 200 ml/m 2 and from 50 up to 150 ml/m 2 respectively.
• an automatically operating apparatus is used provided with a system for automatic replenishment of the processing solutions.
• the processing therein proceeds within a short processing time of from 30 up to 60 seconds from dry-to-dry, and more preferably from 30 up to 50 seconds, for materials used in the image forming system of the present invention.
• a normally used configuration in the automatic processing apparatus shows the following consecutive tank units corresponding with, as consecutive solutions: developer-fixer-rinse water.
• a particularly suitable developer solution is the one comprising a reduced amount of sulphite and ascorbic acid which acts as a main developer and anti-oxidant as well and which is called "low-sludge" developer.
• a particularly suitable fixer solution comprises an amount of less than 25 g of potassium sulphite per liter without the presence of acetic acid wherein said fixer has a pH value of at least 4.5, in order to make the fixer solution quasi odourless.
• a-ketocarboxylic acid compounds may be useful as has been described in EP-A's 0 620 483 and 0 726 491 and in RD 16768, published March 1978. It is possible to use sodium thiosulphate as a fixing agent, thus avoiding the ecologically undesired ammonium ions normally used. For low coating amounts of emulsion crystals rich in chloride a fixation time which is reduced to about 2 to 10 seconds can be attained.
• the developer solution used in the method according to this invention should be replenished not only for decrease of the liquid volume due to cross-over into the next processing solution but also for pH-changes due to oxidation of the developer molecules. This can be done on a regular time interval basis or on the basis of the amount of processed film or on a combination of both. In these circumstances, no dilution and mixing procedures are required before the regeneration bottles are adjusted to the processing unit. Moreover regeneration is kept to a minimum, especially in the processing of materials coated from very low amounts of emulsion crystals rich in silver chloride.
• Preferred minimum regeneration or replenishment amounts are from 100 to 200 ml/m 2 and more preferably from 100 to 150 ml/m 2 for the developer and from 50 to 150 ml/m 2 and more preferably from 50 to 100 ml/m 2 for the fixer solution.
• Replenishment of a developer comprising ascorbic acid or derivatives thereof and a 3-pyrazolidone derivative has been described in EP-A 0 573 700, wherein a method is disclosed for processing with constant activity image-wise exposed silver halide photographic material comprising the steps of
• EP-A 0 552 511 and US-A 5,503,965 and further in EP-A 0 660 175 and EP-Applications Nos. 96203727, filed December 30, 1996 and 97203096, filed October 6, 1997.
• processing apparatus In a conventional processing apparatus the sheet material is transported along a generally horizontal feed path, the sheet material passing from one vessel to another usually via a circuitous feed path passing under the surface of each treatment liquid and over dividing walls between the vessels.
• processing machines having a substantially vertical orientation have also been proposed, in which a plurality of vessels are mounted one above the other, each vessel having an opening at the top acting as a sheet material inlet and an opening at the bottom acting as a sheet material outlet or vice versa.
• substantially vertical is intended to mean that the sheet material moves along a path from the inlet to the outlet which is either exactly vertical, or which has a vertical component greater than any horizontal component.
• the apparatus occupies only a fraction of the floor space which is occupied by a conventional horizontal arrangement.
• the sheet transport path in a vertically oriented apparatus may be substantially straight, in contrast to the circuitous feed path which is usual in a horizontally oriented apparatus.
• the straight path is independent of the stiffness of the sheet material and reduces the risk of scratching compared with a horizontally oriented apparatus.
• it is important to avoid, or at least minimise leakage of treatment liquid from one vessel to another and carry-over as the sheet material passes through the apparatus.
• the treatment liquid in one vessel is not contaminated by contents of the adjacent vessels, that is neither by the treatment liquid of the next higher vessel nor by vapours escaping from the next lower vessel.
• the developing cell of the apparatus is a closed cell and the developing liquid contains an ascorbic acid developing agent as has been described in EP-Application No. 96201753, filed June 24, 1996.
• a method of processing photographic sheet material by use of an apparatus comprising a plurality of processing cells so arranged in order to define a sheet material path through the apparatus, at least one of the cells constituting a developing cell containing a developing liquid, characterized in that the developing cell is a closed cell and the developing liquid contains an ascorbic acid type developing agent.
• EP-A 0 819 992 wherein it was an object to provide an apparatus in which operating components can easily be replaced without the need for substantial re-programming of the CPU. This could be achieved when information concerning characteristics of each operating component is stored in separate memory means.
• a processing apparatus for photographic sheet material comprises several treatment cells, most or all of which are in the form of vessels containing a treatment liquid, such as a developer, a fixer or a rinse liquid.
• a treatment liquid such as a developer, a fixer or a rinse liquid.
• sheet material includes not only photographic material in the form of cut sheets, but also in the form of a web unwound from a roll.
• transport means such as one or more pairs of path-defining drive rollers, and thereafter optionally to a drying unit.
• the time spent by the sheet material in each vessel is determined by the transport speed and the dimensions of the vessel in the sheet feed path direction.
• a sheet material processing apparatus comprising at least one treatment cell, a pair of rotatable path-defining rollers defining a sheet material path through the cell, the path-defining rollers having a closed position in which the path-defining rollers are biased into contact with each other to form a nip through which the sheet material path extends and an open position in which the path-defining rollers are spaced from each other, characterized in that the path-defining rollers are supported by bearings carried by eccentric sleeves which are stationary in the closed position, and means are provided for partly rotating the sleeves thereby to withdraw the path-defining rollers from each other into the open position.
• any combination of two green-light emitting intensifying screens with a double-side coated film may be used, wherein said film comprise cubic and/or ⁇ 111 ⁇ tabular silver chloroiodide emulsion crystals coated from minimum amounts of silver, still offering after exposure by X-rays converted to green light, a sufficient covering power (see therefore e.g.
• EP-A 0 709 730 in rapid ecological processing (with ascorbic acid and/or derivatives thereof as developing agent(s) in a hardener-free developer and an odour-free fixer, free from aluminum ions, thereby reducing sludge; wherein replenishing amounts for developer and fixer are as low as possible) and provided that an optimal relationship is attained between sensitometry and image quality, especially sharpness, partly thanks to low cross-over exposure for said double-side coated films.
• This example demonstrates the advantages of emulsions comprising cubic AgCl(I) crystals having been chemically sensitized with chemically sensitizing compounds comprising selenium over other chemically sensitizing compounds.
• the UAg value of solution 1 (potential value expressed in mV versus a saturated silver/silver chloride reference electrode) was adjusted at a constant value of + 138 mV before starting nucleation by dropwise addition of about 7 ml of a solution having 234 grams of sodium chloride after addition of 0.44 ml of a silver nitrate solution having a concentration of 50 g per liter of demineralized water.
• the emulsion was washed with a solution of demineralized water containing 0.46 g of sodium chloride per litre after flocculation by addition of polystyrene sulphonic acid to the acidified emulsion.
• a solution of demineralized water containing 0.46 g of sodium chloride per litre after flocculation by addition of polystyrene sulphonic acid to the acidified emulsion.
• the pH of the said emulsion was adjusted at 5.15; the pAg at 7.00.
• To the dispersion obtained as described hereinbefore 5 mg of para-toluene thiosulphonate, 1 g of potassium iodide, 15 mg of chloro auric acid, 30 mg of ammonium thiocyanate and 25 mg of tetramethylthio-dithiocarboxylic acid diamide and 3.3 x 10 -6 of a compound comprising Se as indicated in the Table were added at 40°C.
• Chemical sensitization was carried out at 46°C during 150 minutes.
• Spectral sensitization was carried out by means of a mixture of 0.05 mmoles of anhydro-5,5'-diphenyl-3,3'-bis(n-sulphato-propyl)-9-ethyl-oxacarbocyanine hydroxide and 0.09 mmoles of anhydro-5,5'-dichloro-3,3'-bis(n-sulphobutyl)-9-ethyloxacarbocyanine hydroxide. Further, 40 mg (per mole of Ag) of 1-phenyl-5-mercaptotetrazole and 150 mg (per mole of Ag) of 1-p-carboxy-phenyl-5-mercaptotetrazole were added as stabilizers. Resorcinol was added as hardener accelerator in an amount of 2.8 g per mole of Ag.
• Consecutively 0.5 g of polyglycol (MW 6000) was added as a development accelerator; 20 ml of polyoxyethylene surfactant H 17 C 8 -Phenyl-(O-CH 2 -CH 2 ) 8 -O-CH 2 -COOH and in an amount of 140 mg (per mole of Ag) fluoroglucinol was added as a hardener stabilizer together with polymethyl acrylate latex (in an amount of 140 % by weight, based on the amount of gelatin binder) which was used as a plasticizer.
• the composition of the said fixer was as follows: Fixer INVFIX -Ammonium thiosulphate (60 % solution, wherein 1 ml comprises 0.778 g) 710 ml -Sodium metabisulphite 80 g -Sodium acetate 130 g -Acetic acid 31 ml pH ready-for-use (after dilution 1+3) 4.90
• Losses in maximum density are further lower for the materials the emulsions of which have been ripened with selenium compounds suitable for use in the system according to the present invention.
• LIRF-values values for the low intensity reciprocity failure
• a doubling in screen speed is observed for materials having emulsion crystals chemically ripened with selenium compounds for use in the present invention.
• the said values are indicative for the ability to reach a high speed (a speed or sensitivity of a "400"-system): it is repeated that a reference the screen speed of 0.63 corresponds with the screen speed of a CURIX HTU film (trademarketed product from Agfa-Gevaert NV).
• This example demonstrates the advantages of emulsions comprising tabular AgCl(I) crystals having ⁇ 111 ⁇ major planes having been chemically sensitized with chemically sensitizing compounds comprising selenium.
• a nucleation step was performed by introducing solution A and solution B1 simultaneously in dispersion medium C both at a flow rate of 30 ml/min during 30 seconds. After a physical ripening time of 15 min during which the temperature was raised to 70 °C and 97.5 g of gelatin and 1500 ml of water were added and the mixture was stirred for an additional 5 minutes.
• a growth step was performed by introducing by a double jet during 66 minutes solution A starting at a flow rate of 7.5 ml/min and linearly increasing the flow rate to an end value of 37.5 ml/min, and solution B1 at an increasing flow rate as to maintain a constant mV-value, measured by a silver electrode versus a saturated calomel electrode (S.C.E.), of +92 mV.
• S.C.E. saturated calomel electrode
• the average diameter d EM , average thickness t " , average aspect ratio AR were obtained from electron microscopic photographs: the diameter of the grain was defined as the diameter of the circle having an area equal to the projected area of the grain as viewed in the said photographs.
• the average sphere equivalent diameter d EM obtained from the measurement of electric reduction currents obtained by reduction of a silver halide grain with a microscopically fine electrode is given: the sphere equivalent diameter was defined as the diameter of a hypothetical spherical grain with the same volume as the corresponding tabular grain. So a value for d EM " of 1.27 ⁇ m , a value for t " of 0.14 ⁇ m and of AR of 8.8 was found.
• the emulsion was divided in 3 equal parts A, B and C. Before the start of the chemical ripening the mV-value of every emulsion was adjusted at +120 mV with sodium chloride and the pH-value at 5.5 with sodium hydroxide.
• Ripening agents causing a different composition of the ripening solutions used were:
• each emulsion was stabilised with 1-p-carboxyphenyl-5-mercaptotetrazole and after addition of the normal coating additives the solutions were coated simultaneously together with a protective layer containing 1.3 g gelatine per m 2 per side on both sides of a polyethylene terephthalate film support having a thickness of 175 ⁇ m.
• the resulting photographic material contained per side an amount of silver halide corresponding to 4.5 grams of AgNO 3 per m 2 and an amount of gelatin corresponding to 3.55 g/m 2 .
• Samples of these coatings A, B and C were exposed with green light of 540 nm during 0.1 seconds using a continuous wedge.
• the density as a function of the light dose was measured and therefrom were determined the following parameters:
• Emulsion C wherein use is made of a combination of labile sulphur and selenium.

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• 1998
  • 1998-02-13 EP EP98200467A patent/EP0862088A1/de not_active Withdrawn

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