EP0945754B1 - Verfahren zur Herstellung von silberbromidreichen tafelförmigen (100)-Kristallen - Google Patents

Verfahren zur Herstellung von silberbromidreichen tafelförmigen (100)-Kristallen Download PDF

Info

Publication number
EP0945754B1
EP0945754B1 EP99200335A EP99200335A EP0945754B1 EP 0945754 B1 EP0945754 B1 EP 0945754B1 EP 99200335 A EP99200335 A EP 99200335A EP 99200335 A EP99200335 A EP 99200335A EP 0945754 B1 EP0945754 B1 EP 0945754B1
Authority
EP
European Patent Office
Prior art keywords
silver
gelatin
grains
tabular
emulsion
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP99200335A
Other languages
English (en)
French (fr)
Other versions
EP0945754A1 (de
Inventor
Kathy Dr. Elst
Eddy Dr. Michiels
Günther Dr. Helling
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Agfa Gevaert NV
Original Assignee
Agfa Gevaert NV
Agfa Gevaert AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Agfa Gevaert NV, Agfa Gevaert AG filed Critical Agfa Gevaert NV
Priority to EP99200335A priority Critical patent/EP0945754B1/de
Publication of EP0945754A1 publication Critical patent/EP0945754A1/de
Application granted granted Critical
Publication of EP0945754B1 publication Critical patent/EP0945754B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • G03C1/04—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein with macromolecular additives; with layer-forming substances
    • G03C1/053—Polymers obtained by reactions involving only carbon-to-carbon unsaturated bonds, e.g. vinyl polymers
    • 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
    • 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
    • G03C1/07—Substances influencing grain growth during silver salt formation
    • 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
    • G03C1/04—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein with macromolecular additives; with layer-forming substances
    • G03C1/047—Proteins, e.g. gelatine derivatives; Hydrolysis or extraction products of proteins
    • 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
    • G03C2001/03511—Bromide 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
    • G03C2200/00—Details
    • G03C2200/01—100 crystal face

Definitions

  • the present invention relates to a method of preparing photosensitive emulsion grains having ⁇ 100 ⁇ tabular emulsion crystals rich in silver bromide.
  • tabular grains in photographic industry is becoming more important for many applications.
  • the most important reason why tabular grains are so preferred nowadays is their inherent property of having an increased ratio of surface area to volume ratio. This ratio has a positive influence on the effectiveness of the spectral sensitization which is caused by a better interaction between spectral sensitizer and silver halide grain.
  • an enhanced spectral sensitivity resulting therefrom is deteriorated to a lesser extent by desensitization occurring when adding an increased concentration of the spectral sensitizer, which may occur to a significant extent with other types of grains.
  • Another desired effect resulting from the shape of the tabular grain is its increased covering power which is observed after processing and which is the result of an increased surface for the same crystal volume. As a consequence the possibility of coating thinner emulsion layers with lower amounts of silver is offered.
  • tabular grain The type of tabular grain that is used can also play an important role in a lot of different applications. If silver bromide crystals are grown at a high bromide ion excess with respect to the presence of silver ions, tabular grains are easily formed.
  • the anisotropic growth habit that is experienced is due to the presence of usually two or three twin planes parallel to a (111) plane as published by Berriman et al. in Nature, Vol.180(1957), p.293 and J.Hamilton et al. in J.Appl.Phys., Vol.35(1964), p.414.
  • EP-A's 0 534 395; 0 569 971; 0 584 815; 0 584 644; 0 602 878; 0 616 255; 0 617 317; 0 617 320; 0 617 321; 0 617 325; 0 618 492; 0 618 493; 0 653 659 and 0 653 669; US-A's 5,024,931; 5,264,337; 5,275,930; 5,292,632; 5,310,635; 5,314,798; 5,320,938; 5,356,764; 5,601,967; and WO-Applications 94/22051 and 94/22054 are related with ⁇ 100 ⁇ tabular emulsion grains predominantly rich in chloride and a process for preparing them wherein the tabular grain fraction showing ⁇ 100 ⁇ major faces is significant.
  • a photosensitive emulsion comprising tabular silver halide grains rich in silver bromide, having ⁇ 100 ⁇ major faces and an aspect ratio more than 1.5, wherein at least 50 % of the projected area of all grains is provided by said ⁇ 100 ⁇ tabular grains, said method comprising the step of running in a reaction vessel an aqueous silver salt solution and an aqueous alkali halide solution rich in alkali bromide, characterized further as represented in claim 1.
  • a minimum amount of at least 1:5 or about 20 % versus gelatin is required in order to get the preferred tabular ⁇ 100 ⁇ crystal habit and in order to get the desired high coverage of the total projected area of all emulsion grains by ⁇ 100 ⁇ tabular grains having grain characteristics as set forth being an aspect ratio more than 1.5, wherein at least 50 % of the projected area of all grains is provided by said ⁇ 100 ⁇ tabular grains.
  • aspect ratio is well-known by anyone skilled in the art and is defined by the average ratio of the ratio obtained for all tabular grains, calculated from the ratio of surface area and thickness of each individual tabular ⁇ 100 ⁇ crystal or grain.
  • Polyvinyl alcohol is well-known as a hydrophilic colloid, being well soluble in aqueous solutions, but according to the method of the present invention amino-modified polyvinyl alcohol is used in the reaction vessel as hydrophilic colloid besides gelatin. Said amino-modified polyvinyl alcohol is modified in such a way that the ratio by weight of vinylacetalamine dimethylacetal to vinylalcohol in the hydrophilic polymer is from 1:20 up to 1:1 and more preferably from 1:10 up to 1:2.
  • amino modified polymer chain is represented hereinafter in the formula (I), wherein side chains of the main vinyl chain represent as functions alcohol, acetalamine or aminoacetaldehyde dimethylacetal and acetate and wherein said side chains are variable in ratio amounts as set forth hereinbefore.
  • oxidized gelatin present as hydrophilic colloid in the reaction vessel contains methionine in an amount of less than 30 ⁇ moles per mole of gelatin.
  • methionine content of gelatin many references from literature are available as e.g. in J.Phot.Sc., Vol. 28(1980), p.111-118 wherein as most obvious reducing substances in gelatin methionine residues of the macromolecule are determined in reaction with Au(III)-ions.
  • the so-called "gold number” permits determination of amounts of methionine in the gelatin following the rule that 1 ⁇ mole of Au corresponds with 1.6 ⁇ mole of methionine.
  • a total amount of silver nitrate of less than 10 % by weight, and more preferably 0.5 % to 5.0 %, is added during a nucleation step which preferably consists of an approximately equimolecular simultaneous addition (e.g. by the so-called double jet technique) of silver nitrate and halide salts at a pBr of 1.0 to 2.5.
  • pBr is adjusted in the reaction vessel before nucleation at a value of from 2.0 to 2.5 and the vessel is acidified to a pH value of between 1.5 and 3.0.
  • the rest of the silver nitrate and halide salts is added during one or more consecutive double jet growth step(s), separated from each other by several physical ripening steps.
  • the temperature of the reaction vessel which was initially set at a lower level during nucleation (e.g. between 45°C and 55°C), is increased to a temperature within the interval of 60-80°C, and more preferably between 65 and 75°C. Said temperature increase is normally performed between the nucleation step and the first growth step.
  • addition of further amounts of gelatin is normally performed in order to provide sufficient protective action in the colloidal medium of the growing tabular silver halide nuclei.
  • Said gelatin is not as critical as the one added to the reaction vessel before starting nucleation and may be the same oxidized gelatin or normally used non-oxidized gelatin having 30 or more ⁇ moles of methionine per gram or even modified gelatin as e.g. phthalated gelatin.
  • growing said silver halide crystal nuclei proceeds by precipitation of silver halide by means of double-jet precipitation of an aqueous silver nitrate solution and an aqueous solution comprising halide ions, wherein more than 90 % and more preferably up to 95 % by weight of the total amount of silver nitrate is consumed.
  • the different steps of the precipitation can be alternated by physical ripening steps as already suggested hereinbefore or by so called “neutralization steps", during which the pAg (pBr) value is changed to a value required in the next growth step by adding an amount of silver nitrate solution or a water soluble halide salt within a well-defined time of addition by means of the single-jet technique.
  • Alternative ways to regulate the pAg to the desired value before continuing the processing are diluting the emulsion present in the reaction vessel, diafiltration or ultrafiltration and even flocculation and washing procedures, the last techniques being preferred in order to concentrate the emulsion crystals in the reaction vessel. Any combination or any choice of the mentioned techniques may be applied thereto.
  • the ⁇ 100 ⁇ tabular grains rich in silver bromide at the end of the preparation according to the method of the present invention exhibit an average aspect ratio of at least 1.5:1, more preferably of at least 2:1 and even more preferably of at least 5:1, and wherein ⁇ 100 ⁇ tabular grains rich in silver bromide represent a projected area of all grains of at least 50 %, more preferably at least 70 % and in an optimized preparation method even up to at least 90 %.
  • Said ⁇ 100 ⁇ tabular grains rich in silver bromide having been prepared by the steps of precipitating in a reaction vessel with an aqueous silver salt solution and an aqueous alkali halide solution rich in alkali bromide are further composed of silver bromide, silver bromoiodide, silver bromochloride or silver bromochloroiodide, wherein iodide, if present, represents atempoual molar amount of up to 3 mole % and wherein chloride, if present, represents atempoual molar amount of up to 10 mole %.
  • halides differing from bromide are thus added to the reaction vessels at differing steps, depending on the requirement to have a homogeneous or a heterogeneous distribution of the said ions differing from bromide in the crystal volume of the ⁇ 100 ⁇ tabular crystal formed.
  • silver halide differing from silver bromide can be found in one or more internal zones, e.g. in rings, or at the surface of the crystal.
  • the grain surface it may be localized as an epitaxially protruding (often cubic) microcrystal in contact with the host grain or as a consequence of conversion, wherein, especially in the case of ⁇ 100 ⁇ tabular grains rich in silver bromide silver iodide may be enriched at the surface,providing a variable iodide profile thereof.
  • Iodide ions are normally provided by addition of alkali iodide salts or aqueous solution therefrom as e.g. potassium iodide to the reaction vessel, wherein as an alternative iodide may be provided by means of an iodide releasing agent.
  • Patent Applications referring to methods wherein iodide releasing agents are used are e.g. EP-A's 0 563 701, 0 563 708, 0 561 415 and 0 651 284.
  • Preparation of silver bromoiodide emulsion crystals can be achieved by mixing a soluble bromide and a soluble iodide salt in one or more of the halide solutions up to the desired mole % concentrations required in each preparation step or by a triple jet technique, or separate addition of an iodide containing aqueous solution. Due to the lower solubility of silver iodide in comparison with silver bromide, said iodide ions are able to displace bromide ions from the grain, a technique known in the art as conversion.
  • Iodide ions may also be incorporated into the silver halide crystal lattice by the addition of a previously prepared silver iodide micrate emulsion, composed of either pure silver iodide or mixed halides, but as already set forth hereinbefore in a preferred embodiment iodide releasing agents are used, at least partially, e.g. in one or more conversion steps during or at the end of the precipitation. Even bromide releasing agents are not excluded in the precipitation steps according to the method of this invention.
  • Said ⁇ 100 ⁇ tabular grains rich in silver bromide, prepared according to the method of the present invention further have an average thickness of less than 0.30 ⁇ m, and more preferably between 0.10 and 0.20 ⁇ m, and a coefficient of variation of the grain size distribution of the ⁇ 100 ⁇ tabular grains of less than 0.40 and more preferably between 0.10 and 0.30.
  • an increasing flow rate of silver and halide solutions is preferably applied, e.g. a linearly increasing flow rate.
  • the flow rate at the end is about 3 to 10 times greater then at the start of the growth step, wherein the flow rate or addition rate of silver nitrate solutions is performed as programmed before, whereas the flow rate of solutions rich in alkali bromide are run in a variable way as a function of the required pBr or pAg in the reaction vessel at the moment of precipitation.
  • the pBr before the start and during the different stages of the precipitation is maintained at well-defined values which may be variable from step to step and which may be varied by neutralization steps inbetween as will become apparent from the examples hereinafter.
  • nuclei in a separate vessel it is possible in the method of the present invention to prepare nuclei in a separate vessel and to grow the said nuclei in another vessel.
  • growth of the nuclei formed in the nucleation step may be provided by addition of microcrystals having differing compositions in the differing growth steps.
  • the emulsion vessel thus contains a ⁇ 100 ⁇ tabular grain emulsion rich in silver bromide and high amounts of aqueous soluble salts (especially if no microcrystals were added as an alternative during growth). Therefore, after completion of the precipitation a wash technique in order to remove the excess of soluble salts may be applied at a pH value which can vary during washing. If in that case the emulsion is washed by diafiltration by means of a semipermeable membrane. This technique is also called ultrafiltration.
  • Such procedures are 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.
  • pH and pAg are the same as at the end of the precipitation without any adjustment.
  • Emulsion washing has e.g. described in Research Disclosure N° 36544 (1994), Chapter III.
  • the size distribution of the ⁇ 100 ⁇ tabular silver halide particles rich in silver bromide of the photographic emulsions thus obtained can be monodisperse or heterodisperse as already set forth hereinbefore.
  • Two or more types of tabular silver halide emulsions that have been prepared differently, wherein at least one has been preprared according to the method of the present invention can be mixed for forming a photographic emulsion for use in practically useful materials.
  • said tabular silver halide emulsions rich in silver bromide prepared by the method of the present invention can be chemically sensitized as described e.g. in "Chimie et Physique Photographique” by P. Glafkides, in “Photographic Emulsion Chemistry” by G.F. Duffin, in “Making and Coating Photographic Emulsion” by V.L. Zelikman et al, and in "Die Grundlagen der Photographischen Sawe mit Silberhalogeniden” edited by H. Frieser and published by Akademische Verlagsgesellschaft (1968). Chemical sensitisation has e.g. also been described in Research Disclosure N° 36544 (1994) and 38957 (1996), Chapter IV.
  • chemical sensitization can be carried out by effecting the ripening in the presence of small amounts of compounds containing sulphur e.g. thiosulphate, thiocyanate, thioureas, sulphites, mercapto compounds, and rhodamines.
  • Said compounds containing sulphur can also be, at least partially, replaced by compounds containing selenium and/or tellurium.
  • the emulsions may be sensitized also by means of gold-sulphur, gold-sulphur-selenium, gold-selenium ripeners or by means of reductors e.g.
  • the ⁇ 100 ⁇ tabular silver halide emulsions rich in silver bromide 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 and in Research Disclosures Nos. 36544 (1994) and 38957 (1996), Chapter V.
  • Dyes that can be used for the purpose of spectral sensitization include cyanine dyes, merocyanine dyes, complex cyanine dyes, complex merocyanine dyes, hemicyanine dyes, styryl dyes and hemioxonol dyes.
  • Particularly valuable dyes are those belonging to the cyanine dyes, merocyanine dyes and complex merocyanine dyes.
  • a survey of useful chemical classes of spectral sensitizing dyes and specific useful examples in connection with tabular grains is given in the already cited Research Disclosure Item 22534.
  • Oxacarbocyanines have been described e.g. in US-A 5,434,042.
  • Especially preferred green sensitizers in connection with the present invention are anhydro-5,5'-dichloro-3,3'-bis(n.sulfobutyl)-9-ethyl-oxacarbocyanine hydroxide and anhydro-5,5'-dichloro-3,3'-bis(n.sulfo-propyl)-9-ethyloxacarbocyanine hydroxide.
  • Imidacarbocyanines as e.g.
  • the chemical sensitization of ⁇ 100 ⁇ tabular grains rich in silver bromide prepared according to the method of the present invention may proceed in the presence of one or more phenidone and derivatives, a dihydroxy benzene as hydroquinone, resorcinol, catechol and/or a derivative(s) therefrom, one or more stabilizer(s) or antifoggant(s), one or more spectral sensitizer(s) or combinations of said ingredients.
  • a phenidone and derivatives a dihydroxy benzene as hydroquinone, resorcinol, catechol and/or a derivative(s) therefrom, one or more stabilizer(s) or antifoggant(s), one or more spectral sensitizer(s) or combinations of said ingredients.
  • 1-p-carboxyphenyl, 4,4' dimethyl-pyrazolidine-3-one may be added as a preferred auxiliary agent.
  • gelatinous silver halide emulsion having ⁇ 100 ⁇ tabular grains rich in silver bromide prepared according to the method of the present invention is further characterized by the presence of amino-modified polyvinyl alcohol in minor amounts versus gelatin, as more gelatin has been added before grain growth, and before redispersion of the flocculated emulsion.
  • chemical ripening and spectral sensitization typical ratios by weight of gelatin to silver, expressed as an equivalent amount of silver nitrate are from 0.2 up to 0.5 and more preferably from 0.25 up to 0.40.
  • the emulsion according to the present invention is thus ready for being coated in hydrophilic layer(s) which may, just as non-light-sensitive layers of the photographic material comprise compounds preventing the formation of fog or stabilizing the photographic characteristics during the production or storage of the photographic elements or during the photographic treatment thereof.
  • hydrophilic layer(s) may, just as non-light-sensitive layers of the photographic material comprise compounds preventing the formation of fog or stabilizing the photographic characteristics during the production or storage of the photographic elements or during the photographic treatment thereof.
  • Many known compounds can be added as fog-inhibiting agent or stabilizer to the silver halide emulsion layer or to other coating layers in water-permeable relationship therewith such as an undercoat or a protective layer. Suitable examples are e.g.
  • heterocyclic nitrogen-containing compounds such as benzothiazolium salts, nitroimidazoles, nitrobenzimidazoles, chlorobenzimidazoles, bromobenzimidazoles, mercaptothiazoles, mercaptobenzothiazoles, mercaptobenzimidazoles, mercaptothiadiazoles, aminotriazoles, benzotriazoles (preferably 5-methyl-benzotriazole), nitrobenzotriazoles, mercaptotetrazoles, in particular 1-phenyl-5-mercapto-tetrazole, mercaptopyrimidines, mercaptotriazines, benzothiazoline-2-thione, oxazoline-thione, triazaindenes, tetrazaindenes and pentazaindenes, especially those described by Birr in Z.
  • benzothiazolium salts such as benzothiazolium salts, nitroimidazoles, nitrobenzimidazoles, chlor
  • fog-inhibiting compounds include those described in Research Disclosure N° 17643 (1978), Chapter VI and in RD's Nos 36544 (1994) and 38957 (1996), Chapter VII. Many of these fog-inhibiting compounds may have been already added during the chemical ripening of the tabular silver halide crystals rich in silver bromide.
  • gelatin is further added 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 increase in the range from 0.3 to 1.0 is then obtained, wherein extra gelatin added is not required to have a composition as in the preparation step of the grains according to the method of the present invention or during redispersion of the flocculated emulsion.
  • 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 Nos. 36544 (1994) and 38957 (1996), Chapter II.
  • Gelatin added after precipitation is not considered to be a protective colloid as it is not directly adsorbed onto the surface of the ⁇ 100 ⁇ tabular crystals rich in silver bromide, prepared according to the present invention, but it is merely considered as a (hydrophilic colloidal) binder.
  • the said binder of the photographic material having at least one gelatinous emulsion according to the present invention in one or more hydrophilic light-sensitive emulsion layer(s) can be forehardened 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. dimethylol-urea and methylol-dimethylhydantoin, dioxan derivatives e.g. 2,3-dihydroxydioxan, active vinyl compounds e.g. 1,3,5-tri-acryloyl-hexahydro-s-triazine, active halogen compounds e.g. 2,4-dichloro-6-hydroxy-s-triazine, and mucohalogenic acids e.g.
  • aldehydes e.g. formaldehyde, glyoxal, and glutaraldehyde
  • N-methylol compounds e.g. dimethylol-urea and methylol-dimethylhydantoin
  • dioxan derivatives e.g.
  • mucochlo-ric acid and mucophenoxychloric acid can be used alone or in combination.
  • the binder can also be hardened with fast-reacting hardeners such as carbamoylpyridinium salts as disclosed in US-A 4,063,952 and with the onium compounds as disclosed in EP-A 0 408 143.
  • gelatinous photosensitive emulsions comprising ⁇ 100 ⁇ tabular grains rich in silver bromide of the present invention can be used in various types of photographic elements, e.g. black-and-white silver halide photographic materials, like materials used for X-ray diagnostic purposes, for micrographic applications or colour sensitive materials.
  • Photographic materials according to the present invention thus comprise a support and on one or on both sides thereof one or more light-sensitive silver halide emulsion layer(s) coated from a photosensitive emulsion according to the present invention.
  • said photographic materials are single-side or double-side coated radiographic materials.
  • Single-side coated materials are e.g. used in mammographic applications, normally in combination with one intensifying screen at the light-sensitive side of the support in order to get irradiated, without loss in sharpness or detail (e.g. in order to unambiguously detect microcalcifications), by exposure to luminescent phosphors of the screen after exposure to X-rays.
  • Double side-coated X-ray materials are used in diagnostic applications wherein more speed is required (as e.g. for diagnosis of the thorax) and wherein slight loss in sharpness due to cross-over is still acceptable inasmuch as it is not detremendous for the diagnosis. It is clear that from the viewpoint of cost and environmental considerations after use, coated amounts of silver are reduced by the manufacturer up to the lowest acceptable level (e.g. up to at most 3 g/m 2 of silver and per side, said amount expressed as an equivalent amount of silver nitrate although amounts of up to 7 g/m 2 and per side and even up to 10 g/m 2 are not exceptionnal).
  • the coated amount of silver is highly dependant from the required sensitivity or speed of the material and of the required image quality which is directly related with the maximum thickness of the coated layers in the materials, or silver load directly depends on the application as such. So e.g. X-ray materials for non-destructive purposes require high amounts of silver as these materials should be sensitive to direct-x-ray exposure.
  • the single-side or double side coated X-ray materials may contain one single photosensitive emulsion layer, as it is the case for many applications, or it can be built up by two or even more emulsion layers as has e.g. been illustrated in EP-A 0 770 909 and in EP-A 0 890 875.
  • Emulsions of the present invention are advantageously used therein.
  • a material with a single or a duplitized photosensitve emulsion layer coated on one or both sides of the support thus contains at least one gelatinous tabular (100) silver halide emulsion according to the present invention.
  • the material contains blue, green and red sensitive layers each of which can be single coated, but merely consist of double or even triple layers.
  • the photographic material may contain several light-insensitive layers, e.g. a protective layer, one or more backing layers, one or more subbing layers, one or more intermediate layers e.g. filter layers and even an afterlayer containing e.g. the hardening agent(s), the antistatic agent(s), filter dyes for safety-light purposes etc.
  • the photographic element of the present invention may further comprise various kinds of coating physical property modifying addenda as described in RD Nos. 36544 (1994) and 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 the emulsion layer 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.
  • the photographic element of the present invention may further comprise various other additives such as e.g. compounds improving the dimensional stability of the photographic element, UV-absorbers, spacing agents and plasticizers.
  • Suitable additives for improving the dimensional stability of the photographic element are e.g. dispersions of a watersoluble or hardly soluble synthetic polymer e.g.
  • 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's 3,314,794 and 3,352,681, benzophenone compounds as described in JP-A 2784/71, 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 Nos. 36544 (1994)and 38957 (1996), Chapter VI, wherein also suitable optical brighteners are mentioned. UV-absorbers are especially useful in colour materials where they prevent the fading by light of the colour images formed after processing.
  • Spacing agents can 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 hexahydrophthala-te. Other suitable spacing agents have been described in US-A 4,614,708.
  • the photographic material can contain several non-light sensitive layers, e.g. an antistress topcoat layer, one or more backing layers in case of single-side coated materials, and one or more intermediate layers eventually containing filter- or antihalation dyes that absorb scattering light and thus promote image sharpness.
  • Suitable light-absorbing dyes used in these intermediate layers are described in e.g. US-A's 4,092,168; 4,311,787; 5,380,634; 5,344,749; 5,478,708; 5,502,205; in EP-A's 0 586 748, 0 786 497, 0 781 816, 724 191, in DE 2,453,217, and in GB-A 7,907,440.
  • One or more backing layers can be provided at the non-light sensitive side of the support of materials coated with at least one emulsion layer at only one side of the support.
  • These layers which can serve as anti-curl layer can contain e.g. matting agents like silica particles, lubricants, antistatic agents, light absorbing dyes, opacifying agents, e.g. titanium oxide and the usual ingredients like hardeners and wetting agents.
  • the support of the photographic material may be opaque or transparent, e.g. a paper support or resin support.
  • a paper support preference is given to one coated at one or both sides with an ⁇ -olefin polymer, e.g. a polyethylene layer which optionally contains an antihalation dye or pigment.
  • an organic resin support e.g. cellulose nitrate film, cellulose acetate film, poly(vinyl acetal) film, polystyrene film, poly(ethylene terephthalate) or poly(ethylene naphthalate) film, polycarbonate film, polyvinylchloride film or poly- ⁇ -olefin films such as polyethylene or polypropylene film.
  • the thickness of such organic resin film is preferably comprised between 0.07 and 0.35 mm.
  • These organic resin supports are preferably coated with a subbing layer which can contain water insoluble particles such as silica or titanium dioxide.
  • the photographic material of the present invention containing in at least one photosensitive layer ⁇ 100 ⁇ tabular emulsion grains prepared according to the present invention can be image-wise exposed by any convenient radiation source in accordance with its specific application (as e.g. colour photography, black-and-white photographic materials for medical diagnosis irradiated by X-rays non-destructive testing materials irradiated by direct X-rays; black-and-white materials for graphic or micrographic applications, etc.).
  • any convenient radiation source as e.g. colour photography, black-and-white photographic materials for medical diagnosis irradiated by X-rays non-destructive testing materials irradiated by direct X-rays; black-and-white materials for graphic or micrographic applications, etc.
  • processing conditions and composition of processing solutions are dependent from the specific type of photographic material in which the tabular grains prepared according to the present invention are applied.
  • materials for X-ray diagnostic purposes may be adapted to rapid processing conditions.
  • an automatically operating processing apparatus is used provided with a system for automatic regeneration of the processing solutions.
  • the forehardened material may be processed using one-part package (hardener-free) chemistry or three-part package (hardener-containing) chemistry, depending on the processing application determining the degree of hardening required in said processing cycle. Applications within total processing times of 30 seconds and lower up to 90 seconds, known as common praxis, are possible. From an ecological point of view it is e.g. possible to use sodium thiosulphate instead of ammonium thiosulphate in the fixer and ascorbic acid, reductic acid or derivatives therefrom in the developer as has e.g. been disclosed in EP-A 0 732 619 and in US-A's 5,593,817 and 5,604,082.
  • a silver halide emulsion is thus provided with silver halide crystals rich in silver bromide having a tabular ⁇ 100 ⁇ crystal habit, wherein tabular grains are present in high amounts, thus covering a highvisual projected area of all grains according to the object of the present invention.
  • Emulsion A comparative emulsion
  • a first neutralization step was performed by addition of the 1.96 molar solution of potassium bromide within a time interval of 330 s at a rate of 7.5 ml/min.
  • a second neutralization step was further performed by double jet precipitation of the 1.96 molar solutions of silver nitrate and potassium bromide, wherein the silver nitrate solution was added during 60 s at a rate of 7.5 ml/min., while adding potassium bromide in order to maintain the potential value at 0 mV vs. a saturated calomel electrode.
  • a third neutralization step was performed by addition of the silver nitrate solution at a rate of 7.5 ml/min. during 440 s.
  • a fourth neutralization step was further performed by double jet precipitation of the 1.96 molar solutions of silver nitrate and potassium bromide, wherein the silver nitrate solution was added during 100 s at a rate of 7.5 ml/min., while adding potassium bromide in order to maintain the potential value at 100 mV vs. a saturated calomel electrode.
  • a second growth step 907 ml of the silver nitrate solution were added in 2456 s at a starting velocity of 7.5 ml/min. up to a maximum rate of 36.9 ml/min. at the end of precipitation, while simultaneously adding a solution of 1.93 molar of potassium bromide and 0.03 molar of potassium iodide at a continously varying rate in order to maintain the potential at a value of 100 mV throughout the whole second growth step.
  • Emulsion B (inventive emulsion)
  • the silver bromoiodide emulsion crystals having a composition of 99 mole % of silver bromide and 1 mole % of silver iodide as well were evaluated by electron microscopic techniques: more than 50 % of the said grains had a tabular crystal habit and an average equivalent volume diameter of 0.70 ⁇ m.
  • the replicas made from grains of this emulsion are represented in Figure 2 and are illustrative for the presence of crystals showing a ⁇ 100 ⁇ tabular crystal habit and an aspect ratio of more than 1.5 for a total projective surface of more than 50 % of the projective surface of all grains, whereas less than 5 % of the said surface are occupied by ⁇ 111 ⁇ tabular grains having an aspect ratio of more than 2.
  • Emulsion C (inventive emulsion)
  • the silver bromoiodide emulsion crystals having a composition of 99 mole % of silver bromide and 1 mole % of silver iodide as well were evaluated by electron microscopic techniques: more than 50 % of the said grains had a tabular crystal habit and an average equivalent volume diameter of 0.76 ⁇ m.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Silver Salt Photography Or Processing Solution Therefor (AREA)

Claims (8)

  1. Verfahren für den Ansatz einer strahlungsempfindlichen Emulsion mit silberbromidreichen Silberhalogenid-Tafelkörnern, die {100}-Hauptflächen und ein Aspektverhältnis größer als 1,5 aufweisen und in denen mindestens 50 % der projizierten Fläche aller Körner von diesen {100}-Tafelkörnern stammen, wobei das Verfahren den Schritt Eingießen einer wässrigen Silbersalzlösung und einer wässrigen alkalibromidreichen Alkalihalogenidlösung in ein Reaktionsgefäß umfasst, dadurch gekennzeichnet, dass das Reaktionsgefäß vor dem Anfang des Eingießens der Körner eine Menge an mit Aminogruppen modifiziertem Polyvinylalkohol in einer wässrigen Gelatinelösung enthält, wobei das Gewichtsverhältnis von dem mit Aminogruppen modifizierten Polyvinylalkohol zu der Gelatine in der wässrigen Lösung wenigstens 1:5 beträgt und wobei die obere Grenze des Verhältnisses 1:1 beträgt, wobei es sich bei der Gelatine um oxidierte Gelatine mit einem Methioningehalt kleiner als 30 µmol pro mol Gelatine handelt, und wobei die allgemeine Struktur des mit Aminogruppen modifizierten Polyvinylalkohols der Formel (I) entspricht,
    Figure 00260001
    in der Seitenketten der Vinyl-Hauptkette Alkohol, Acetalamin oder Aminoacetaldehyddimethylacetal und Acetat als Funktionsgruppen darstellen und in der die Mengenverhältnisse dieser Seitenketten veränderlich sind.
  2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, dass das Gewichtsverhältnis von dem mit Aminogruppen modifizierten Polyvinylalkohol zu der Gelatine in der wässrigen Lösung wenigstens 1:3 beträgt.
  3. Verfahren nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass das Gewichtsverhältnis von dem Vinylacetalamindimethylacetal zu dem Vinylalkohol in dem mit Aminogruppen modifiziertem Polyvinylalkohol von 1:20 bis 1:1 beträgt.
  4. Verfahren nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass das Gewichtsverhältnis von dem Vinylacetalamindimethylacetal zu dem Vinylalkohol in dem mit Aminogruppen modifiziertem Polyvinylalkohol von 1:10 bis 1:2 beträgt.
  5. Verfahren nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, dass sich die silberbromidreichen Körner aus Silberbromid, Silberbromidiodid, Silberbromidchlorid oder Silberbromidchloridiodid zusammensetzen, wobei das gegebenenfalls enthaltene Iodid eine prozentuale Molmenge von höchstens 3 mol-% ausmacht und wobei das gegebenenfalls enthaltene Chlorid eine prozentuale Molmenge von höchstens 10 mol-% ausmacht.
  6. Strahlungsempfindliche Emulsion, die nach dem Verfahren nach einem der Ansprüche 1 bis 5 angesetzt wird.
  7. Fotografisches Material, das einen Träger und auf einer Seite bzw. auf beiden Seiten des Trägers eine oder mehrere aus einer strahlungsempfindlichen Emulsion nach Anspruch 6 aufgetragene lichtempfindliche Silberhalogenid-Emulsionsschichten umfasst.
  8. Fotografisches Material nach Anspruch 7, dadurch gekennzeichnet, dass es ein einseitig oder doppelseitig emulsioniertes Röntgenmaterial ist.
EP99200335A 1998-03-23 1999-02-05 Verfahren zur Herstellung von silberbromidreichen tafelförmigen (100)-Kristallen Expired - Lifetime EP0945754B1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP99200335A EP0945754B1 (de) 1998-03-23 1999-02-05 Verfahren zur Herstellung von silberbromidreichen tafelförmigen (100)-Kristallen

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
EP98200901 1998-03-23
EP98200901 1998-03-23
EP99200335A EP0945754B1 (de) 1998-03-23 1999-02-05 Verfahren zur Herstellung von silberbromidreichen tafelförmigen (100)-Kristallen

Publications (2)

Publication Number Publication Date
EP0945754A1 EP0945754A1 (de) 1999-09-29
EP0945754B1 true EP0945754B1 (de) 2003-11-19

Family

ID=26150145

Family Applications (1)

Application Number Title Priority Date Filing Date
EP99200335A Expired - Lifetime EP0945754B1 (de) 1998-03-23 1999-02-05 Verfahren zur Herstellung von silberbromidreichen tafelförmigen (100)-Kristallen

Country Status (1)

Country Link
EP (1) EP0945754B1 (de)

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2920429B2 (ja) * 1991-02-16 1999-07-19 コニカ株式会社 ハロゲン化銀乳剤の製造方法
DE4318438A1 (de) * 1993-06-03 1994-12-08 Agfa Gevaert Ag Fotografisches Aufzeichnungsmaterial

Also Published As

Publication number Publication date
EP0945754A1 (de) 1999-09-29

Similar Documents

Publication Publication Date Title
US5595864A (en) Method for making tabular silver halide grains
EP0712034B1 (de) Verfahren zur spektralen Sensibilisierung von tafelförmigen Silberhalogenidkörnern
US6087085A (en) Preparation method of morphologically homogeneous (111) tabular crystals rich in silver bromide
EP0677773A1 (de) Tafelförmige Kristalle enthaltende Silberhalogenidemulsionen und Verfahren zu deren Verarbeitung
US5601969A (en) Preparation of tabular emulsion grains rich in chloride
EP0911687B1 (de) Verfahren zur Herstellung von morphologisch homogenen silberbromidreichen tafelförmigen (111)-Kristallen
US6080536A (en) Method of preparing (100) tabular grains rich in silver bromide
EP0945754B1 (de) Verfahren zur Herstellung von silberbromidreichen tafelförmigen (100)-Kristallen
EP0503700A1 (de) Verfahren zur Herstellung von Jodobromid-Emulsionen, die monodisperse tabulare Körner enthalten
US5693370A (en) Method of manufacturing a silver halide photographic silver halide material suitable for rapid processing applications
EP0569075B1 (de) Verfahren zur Herstellung von tafelförmigen Silberhalogenid-Körnern
EP0843208A1 (de) Verfahren zur Herstellung silberbromidreicher Tafelkörner in Gegenwart spezifischer Gelatinen
EP0653669B1 (de) Chloridreiche Tafelkornemulsion mit (100)-Hauptflächen
EP0678772A1 (de) Lichtempfindliches Silberchlorobromojodid- oder Silbuchlorojodid-Tafelkörner enthaltendes Material
EP0953867B1 (de) Verfahren zur spektralen Sensibilisierung von tafelförmigen Silberhalogenidkörnern
EP0843207B1 (de) Verfahren zur Herstellung einer verbesserten photographischen Emulsion mit chloridreichen Tafelkörnern
US6136524A (en) Light-sensitive emulsion having (100) tabular grains rich in silver chloride and method for preparing said grains
US5733715A (en) Silver halide photographic materials comprising silver bromide or bromoiodide emulsions having triangular tabular crystals
EP0752617B1 (de) Erzeugungsverfahren für photographisches Silberhalogenidmaterial geeignet für schnelle Verarbeitungsanwendungen
EP0651284A1 (de) Fällung von Silberhalogenidkristallen, die lodid enthalten
US6083678A (en) Method for preparing a light-sensitive emulsion having (100) tabular grains rich in silver chloride
US6558892B2 (en) Method of preparing ultrathin light-sensitive tabular grain emulsions rich in silver bromide
EP0770909A1 (de) Photographisches Silberhalogenidmehrschichtmaterial und Verfahren zu dessen Herstellung
US6312882B1 (en) Silver halide emulsions comprising tabular crystals, emulsions and the processing thereof
US6436621B1 (en) Multilayer silver halide photographic material and process for preparing the same

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): BE DE FR GB

AX Request for extension of the european patent

Free format text: AL;LT;LV;MK;RO;SI

17P Request for examination filed

Effective date: 20000329

AKX Designation fees paid

Free format text: BE DE FR GB

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: AGFA-GEVAERT

17Q First examination report despatched

Effective date: 20030305

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): BE DE FR GB

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20031119

Ref country code: BE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20031119

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REF Corresponds to:

Ref document number: 69912873

Country of ref document: DE

Date of ref document: 20031224

Kind code of ref document: P

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20040219

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040220

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20040219

26N No opposition filed

Effective date: 20040820

EN Fr: translation not filed