EP1387366A2 - Ecran luminescent excitable comprenant une couche antidispersion - Google Patents

Ecran luminescent excitable comprenant une couche antidispersion Download PDF

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Publication number
EP1387366A2
EP1387366A2 EP03102343A EP03102343A EP1387366A2 EP 1387366 A2 EP1387366 A2 EP 1387366A2 EP 03102343 A EP03102343 A EP 03102343A EP 03102343 A EP03102343 A EP 03102343A EP 1387366 A2 EP1387366 A2 EP 1387366A2
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EP
European Patent Office
Prior art keywords
layer
phosphor
phosphor screen
lead
support
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EP03102343A
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German (de)
English (en)
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EP1387366A3 (fr
Inventor
Luc AGFA-GEVAERT Struye
Paul AGFA-GEVAERT Leblans
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Agfa HealthCare NV
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Agfa Gevaert NV
Agfa HealthCare NV
Agfa Gevaert AG
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Priority to EP03102343A priority Critical patent/EP1387366A3/fr
Publication of EP1387366A2 publication Critical patent/EP1387366A2/fr
Publication of EP1387366A3 publication Critical patent/EP1387366A3/fr
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    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21K—TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
    • G21K4/00—Conversion screens for the conversion of the spatial distribution of X-rays or particle radiation into visible images, e.g. fluoroscopic screens
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21K—TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
    • G21K4/00—Conversion screens for the conversion of the spatial distribution of X-rays or particle radiation into visible images, e.g. fluoroscopic screens
    • G21K2004/04—Conversion screens for the conversion of the spatial distribution of X-rays or particle radiation into visible images, e.g. fluoroscopic screens with an intermediate layer
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21K—TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
    • G21K4/00—Conversion screens for the conversion of the spatial distribution of X-rays or particle radiation into visible images, e.g. fluoroscopic screens
    • G21K2004/06—Conversion screens for the conversion of the spatial distribution of X-rays or particle radiation into visible images, e.g. fluoroscopic screens with a phosphor layer
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21K—TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
    • G21K4/00—Conversion screens for the conversion of the spatial distribution of X-rays or particle radiation into visible images, e.g. fluoroscopic screens
    • G21K2004/10—Conversion screens for the conversion of the spatial distribution of X-rays or particle radiation into visible images, e.g. fluoroscopic screens with a protective film

Definitions

  • the present invention relates to a method for storing and reproducing a radiation image, making use of a radiation image storage sheet or panel and to a radiation image storage screen or panel with a stimulable phosphor layer and a layer arrangement suitable for use in the said radiation image storing and reproducing method.
  • an image storage screen or panel known as comprising a sheet or layer comprising a stimulable phosphor.
  • the method thereby comprises the steps of causing the stimulable phosphor of the storage panel to absorb radiation energy having passed through an object or having radiated from an object; sequentially exciting the stimulable phosphor with an electromagnetic wave such as visible light or infrared rays (i.e., stimulating light) in order to release the radiation energy stored in the phosphor as light emission (i.e., stimulated emission); photoelectrically detecting the emitted light to obtain electric signals; and reproducing the radiation image of the object as a visible image from the electric signals.
  • an electromagnetic wave such as visible light or infrared rays (i.e., stimulating light)
  • light emission i.e., stimulated emission
  • photoelectrically detecting the emitted light to obtain electric signals
  • reproducing the radiation image of the object as a visible image from the electric signals.
  • the panel is further subjected to a step for erasing radiation energy
  • a beam of visible or infra-red light scans the panel in order to stimulate the release of stored energy as light that is detected and converted to sequential electrical signals which are processed in order to produce a visible image.
  • the phosphor should store as much as possible of the incident X-ray energy and emit as little as possible of the stored energy until stimulated by the scanning beam. This is called “digital radiography” or “computed radiography”.
  • image definition is, to a large extent, defined by scattering properties of the phosphor layer.
  • phosphor layer thickness is limited by the desired sharpness. More particularly in mammographic applications sharpness should be extremely high in order to have an image having high enough a diagnostic value, without leaving any doubt with respect to presence or absence of microcalcifications, in order to furthermore avoid retakes. Phosphor layer thicknesses should therefore not exceed 150 ⁇ m in order to get the desired sharpness or image definition.
  • image definition does not reach the expected level and that although all measures have been taken in order to reach it, an unexpectedly lower level is attained.
  • the image quality that is produced by any radiographic system using a phosphor screen thus also by a digital radiographic system, largely depends on the construction or layer arrangement of the phosphor screen. In general the thinner a phosphor screen at a given amount of absorption of X-rays, the better the image quality will be. This means that the lower the ratio of binder to phosphor of a phosphor screen, the better the image quality, attainable with that screen, will be. Optimum sharpness can thus be obtained when screens without any binder are used. Such screens can be produced e.g. by physical vapour deposition, which may be thermal vapour deposition, sputtering, electron beam deposition or other of phosphor material on a substrate. However, this production method can not be used in order to produce high quality screens with every arbitrary phosphor available. The mentioned production method leads to the best results when phosphor crystals with high crystal symmetry and simple chemical composition are used.
  • alkali metal halide phosphors in storage screens or panels is well known in the art of storage phosphor radiology and the high crystal symmetry of these phosphors makes it possible to simultaneously provide structured screens and binderless screens.
  • a binderless storage phosphor screen comprises an alkali metal storage phosphor characterised in that said screen shows an XRD-spectrum with a (100) diffraction line having an intensity I 100 and a (110) diffraction line having an intensity I 110 , so that I 100 /I 110 ⁇ 1.
  • Such a phosphor screen shows a better compromise between speed and sharpness.
  • the above mentioned object has been realised by providing a stimulable phosphor screen having the specific features defined in claim 1. Specific features for preferred embodiments of the invention are disclosed in the dependent claims. Further advantages and embodiments of the present invention will become apparent from the following description and drawings.
  • the support or undercoat layer may cause scattering of X-rays, effecting the said support or undercoat layer, a phenomenon also known as "backscattering".
  • the said “backscattering” is generated in all layers, known as “supporting” or “undercoating”, wherein said undercoating layers may be between the supporting and the phosphor layers as intermediate layers.
  • a stimulable phosphor screen or panel comprises a phosphor layer and a support, characterised in that an intermediate layer arrangement of an X-ray absorbing foil or layer and, farther from the support, a stimulated light reflecting foil is present between said support and said phosphor layer.
  • the said layer arrangement strongly absorbs X-rays, when said layer arrangement is present between phosphor layer and underlying support layer, moreover providing a substantially improved sharpness. This result can be interpreted to be due to the smaller distance over which "backscattering" is set free in order to effect "neighbouring pixels".
  • a strongly absorbing material for the said intermediate layer lead or a lead compound is highly preferred.
  • a stimulable phosphor screen or panel wherein said intermediate layer arrangement comprises an X-ray absorbing layer,wherein as a lead compound an oxide or a hydroxide of lead metal is dispersed in a binder and wherein said binder containing the lead compound is a matrix of a polycondensation product of a metal alkoxide species. It has been established that it is sufficient to have a material in the intermediate layer arrangement as set forth above, wherein the said material may be absorbing X-rays to a lower extent, but wherein it nevertheless avoids scattering to a great extent. As a consequence presence of less scattered light is not related with a real "depth" where scattered radiation is generated as no more than one pixel is overlapped by said "scattering".
  • a stimulable phosphor screen or panel wherein said binder containing the lead compound is a matrix of an inorganic network of alkoxymetal substituted organic polymers or copolymers matrix.
  • a stimulable phosphor screen or panel wherein said matrix is derived from a cross-linking agent selected from the group consisting of dialkoxysilanes, trialkoxysilanes, tetraalkoxysilanes, titanates, zirconates and aluminates; and a colloid of silica, and wherein said matrix comprises a colloid of an oxide or a hydroxide of lead metal.
  • a preferred support for the preferred intermediate layer arrangement therefore is amorphous carbon(a-C), not only thanks to the black, radiation absorbing particles, but, to a more remarkable extent, thanks to the generation of very little backscattering.
  • a thin intermediate layer comprising an intermediate layer arrangement as set forth above, supported by amorphous carbon is highly recommended.
  • a "thick" layer, foil or screen of lead may be present in a cassette wherein a phosphor plate is present, said foil or screen is known to have been situated at a distance far from the phosphor layer and not as a coated layer between said phosphor layer and the support layer of the said phosphor layer.
  • Amorphous carbon film supports suitable for use in the present invention are commercially available through, e.g., Tokay Carbon Co, LTD of Tokyo, Japan or Nisshinbo Industries, Inc of Tokyo, Japan, where they are termed "Glass-Like Carbon Film", or "Glassy Carbon”.
  • Amorphous carbon is moreover suitable to be applied in the production of binderless phosphor screens by means of chemical vapour deposition in vacuum, as the support on which the phosphor is deposited can be heated up to a temperature of about 400°C, thus requiring use of a thermostable support. Therefore, though being a support containing only elements with a low atomic number, a polymeric support may be applied, but is not the most suitable, opposite to more preferred amorphous carbon supports.
  • the thickness of the amorphous carbon layer may range from 100 ⁇ m up to 3000 ⁇ m, a thickness between 500 ⁇ m and 2000 ⁇ m being preferred as a compromise between flexibility, strength and X-ray absorption.
  • the phosphor screens or panels as described in EP-Application No. 02100764, filed June 28, 2002, provided with a lead foil as an intermediate layer between the said a-C layer support and the phosphor layer are thus highly preferred within the scope of the present invention.
  • stimulable phosphor screens with a substrate, characterised in that said substrate has a reflectivity of more than 80% as disclosed in in EP-Application No. 02100763, filed June 28, 2002. Said reflectivity is preferably provided by an aluminum layer. Also in US-A 4,618,778 it has also been disclosed to add a reflecting layer under the layer containing the phosphor dispersed in a binder as is, in a particular embodiment of the present invention, applied herein.
  • the balance between reflecting and absorbing properties of the system should be optimised: when priority is given to a high speed a reflectance of 80 % will be strived at, whereas, when a higher sharpness is envisaged (as e.g. in mammographic systems) reflection should be lower but an absorption of up to 80 % will be required.
  • the lead containing layer covering the support absorbs at least 80 % (in mammographic applications) of the stimulating light and reflects at least 80 % (in generally applied radiography) of the stimulated light.
  • the said layer is covered with an adjacent thin layer, e.g. an aluminum or another reflecting layer, in order to reach, or even to exceed the reflection values set forth above.
  • an adjacent thin layer e.g. an aluminum or another reflecting layer
  • use can be made thereof as such, in order to further optimise the layer arrangements in the storage phosphor panel, and in order to get an optimised image definition.
  • a strong X-ray absorbing lead foil in combination with a thin reflecting aluminum foil.
  • a stimulable phosphor screen or panel wherein said intermediate layer arrangement comprises as an X-ray absorbing layer a layer of lead or a layer with a lead compound in a binder,as disclosed hereinbefore, and an aluminum layer as a stimulated light reflecting foil.
  • storage phosphor panels are not restricted to "binderless storage phosphors" as the "vapour deposited phosphors" further, throughout this text, meant as phosphors produced by any method selected from the group consisting of thermal vapour deposition, chemical vapour deposition, electron beam deposition, radio frequency deposition and pulsed laser deposition. This vapour deposition is preferably carried out under conditions as described in EP-A-1 113 458.
  • conventional phosphors as the conventional CsI:Eu scintillator phosphor as in Fig. 2 may be used wherein in that panel, in a particular embodiment a layer of lead glass (2') between a conventional phosphor layer (1') with CsI:Eu as a conventional phosphor and an electronic detector (CCD, Diode array) as layer (3') is illustrating a panel according to the present invention.
  • well-known storage phosphors as e.g. BaFBr-type phosphors known from US-A 5,514,298, may be advantageously applied in a panel as set forth in Fig.
  • a storage phospor panel having a lead foil as an intermediate layer between support (3) (PET, Al, Glass, Amorphous Carbon) and phosphor layer (1), coated with a stimulable phosphor (BaFBr:Eu, CsBr:Eu), wherein lead/lead compound foil (2) is situated as an intermediate layer inbetween phosphor layer (1) and support (3).
  • support (3) PET, Al, Glass, Amorphous Carbon
  • phosphor layer (1) coated with a stimulable phosphor (BaFBr:Eu, CsBr:Eu), wherein lead/lead compound foil (2) is situated as an intermediate layer inbetween phosphor layer (1) and support (3).
  • Preferred supports for a storage phosphor screen of the present invention are selected from the group consisting of ceramics, glass, polymeric film and amorphous carbon as set forth hereinbefore, without however excluding aluminum, as its function is differing from the preferred light-reflecting thin aluminum layer farther from the aluminum support than the layer containing the lead or lead compound in the intermediate layer arrangement between support and phosphor layer.
  • the polymeric films especially heat stable polyester films (as e.g. polyethylene terephthalate and polyethylene naphthalate) with a thickness between 100 and 1000 ⁇ m are preferred as a support in a screen according to the present invention.
  • the supports, used in screens of the present invention are treated so that, apart for the desired X-ray absorbing layer as a specific layer, preferably coated with a stimulated emission light reflecting layer, a reduced amount of additional special layers should be coated on the supports in case of vapour deposition of needle-shaped phosphors.
  • the support for use in a storage phosphor screen of the present invention is glass
  • frit glass made by heating glass particles or fibres at high enough a temperature in order to fuse them together in a manner, sufficiently to form a plate.
  • the surface of such a plate of frit glass is uneven and the profile depends on the diameter of the glass beads used to form the plate of frit glass.
  • the X-ray absorbing layer coated thereupon may further depict the unevenness in the support for the vapour deposited phosphor layer. This may however help to tightly vapour deposit the phosphor crystals in needle-shaped form.
  • a phosphor screen or panel wherein said support is selected from the group consisting of ceramics, glass, amorphous carbon, aluminum and polymeric films.
  • a flexible intermediate layer arrangement comprising as an X-ray absorbing layer a layer of lead or the said layer having a lead compound (as lead oxide or hydroxide) as disclosed before; and, as a stimulated light reflecting foil adjacent thereto, an aluminum layer; is provided on a flexible, polymeric support, with an adhesive layer onto said support and the said intermediate layer arrangement, coated over said adhesive layer.
  • a lead compound as lead oxide or hydroxide
  • Lead or lead oxide layers have, as a particular advantage that they do not absorb moisture and that such a flexible lead or lead oxide layer coated onto a polymeric support has a reduced propensity to produce static electricity during use.
  • a phosphor screen or panel is provided, having between said intermediate layer arrangement and the support, a moisture-repellent parylene layer.
  • a phosphor screen or panel is provided, having between said intermediate layer arrangement and the phosphor layer a moisture-repellent parylene layer.
  • a phosphor screen or panel is provided, having between said intermediate layer arrangement and the phosphor layer and between said intermediate layer arrangement and the support, a moisture-repellent parylene layer.
  • Polylene a generic name for thermoplastic polymers and copolymers based on p-xylylene and substituted p-xylylene monomers, has been shown to possess suitable physical, chemical, electrical, and thermal properties for use in integrated circuits. Deposition of such polymers by vaporisation and decomposition of a stable dimer, followed by deposition and polymerisation of the resulting reactive monomer, is discussed by Ashok K. Sharma in “Parylene-C at Subambient Temperatures", published in the Journal of Polymer Science: Part A: Polymer Chemistry, Vol. 26, at pages 2953-2971 (1988).
  • Parylene polymers are typically identified as Parylene-N, Parylene-C, and Parylene-F corresponding to non-substituted p-xylylene, chlorinated p-xylylene, and fluorinated p-xylylene, respectively. Properties of such polymeric materials, including their low dielectric constants, are further discussed by R. Olson in "Xylylene Polymers", published in the Encyclopedia of Polymer Science and Engineering, Volume 17, Second Edition, at pages 990-1024 (1989). Parylene-N is deposited from non-substituted p-xylyene at temperatures below about 70-90°C.
  • the substituted dimers are typically cracked at temperatures which degrade the substituted p-xylylene monomers, and the parylene-C and parylene-F films must be deposited at temperatures substantially lower than 30°C.
  • the moisture-protecting coating may be adhered to one or both sides of the intermediate layer arrangement by chemical vapour deposition (CVD) or lamination.
  • the vapour deposited or laminated film(s) are thus poly-p-xylylene film(s) deposited in vacuum or laminated.
  • a poly-p-xylylene polymer film has repeating units in the range from 10 to 10000, wherein each repeating unit has an aromatic nuclear group, whether or not substituted.
  • Each substituent group can be the same or different and can be any inert organic or inorganic group which can normally be substituted on aromatic nuclei. Illustrations of such substituent groups are alkyl, aryl, alkenyl, amino, cyano, carboxyl, alkoxy, hydroxylalkyl, carbalkoxy and like radicals as well as inorganic radicals such as hydroxyl, nitro, halogen and other similar groups which are normally substitutable on aromatic nuclei.
  • substituted groups are those simple hydrocarbon groups such as the lower alkyl such as methyl, ethyl, propyl, butyl, hexyl and halogen groups particularly chlorine, bromine, iodine and fluorine as well as the cyano group and hydrogen.
  • These polymers are commonly formed on phosphor screens or panels by the pyrolysis and vapour deposition of di-p-xylylene.
  • the diradicals formed in the manner described above are made to impinge upon the surface of the particulate material having surface temperatures below 200°C and below the condensation temperature of the diradicals present thereby condensing thereon and spontaneously polymerising.
  • the commercially available di-p-xylylene composition sold by the Union Carbide Co. under the trademark "Parylene" is thus preferred.
  • compositions for the protective moistureproof layer(s) covering the intermediate layer arrangement at one or both sides thereof the unsubstituted "Parylene N", the monochlorine substituted "Parylene C”, the dichlorine substituted "Parylene D” and the “Parylene HT” (a completely fluorine substituted version of Parylene N, opposite to the other "parylenes” resistant to heat up to a temperature of 400°C and also resistant to ultra-violet radiation, moisture resistance being about the same as the moisture resistance of "Parylene C”: see the note about "High Performance Coating for Electronics Resist Hydrocarbons and High Temperature” written by Guy Hall, Specialty Coating Systems, Indianapolis, available via www.scscookson.com.
  • parylene layer(s) is(are) halogen-containing. More preferably said parylene layer is selected from the group consisting of a parylene D, a parylene C and a parylene HT layer.
  • a lacquer layer may be provided, wherein any of the well-known lacquers may be used to provide a thin, tough, transparent overcoat for the lead foil screen whereupon the stimulable phosphor layer may be deposited.
  • the lacquers may be applied as a liquid by any conventional manner and dried to form a tough, smooth overcoat finish to the element.
  • a fluorosurfactant layer may be applied on top of said lacquer layer.
  • a lacquer layer comprising e.g. polymerized polyvinyl chloride may be coated and dried.
  • a thin layer of a fluorosurfactant may then be applied over the lacquer layer and the structure dried thoroughly.
  • Lead foils or foils of lead oxide dispersed in a binder as set forth hereinbefore are commercially available.
  • a foil of differing thicknesses can be applied, but preferred is a foil having a thickness of from 25 ⁇ m up to 150 ⁇ m. The ultimately chosen thickness strongly depends on the application as envisaged and on the energy of the incident X-rays related therewith.
  • a thickness for the (vapour deposited) reflecting aluminum layer is normally in the range from 0.5 up to 5 ⁇ m, more preferably about 1 ⁇ m.
  • a lead foil layer may, besides Pb contain other metals up to a minor extent as e.g. Sn and Sb.
  • This lead foil is then applied to the film support using a conventional adhesive therefor.
  • a conventional adhesive e.g. UK 2600 mixed with Zappon® blue and supplied by BASF, Dusseldorf, Germany, may e.g. be used.
  • Other adhesives can also be used as long as they are compatible with the lead layer and as long as they do not interfere with the recording of an X-ray image.
  • the lead foil layer is then laminated thereto.
  • Lead oxide dispersed in a suitable binder and coated in a layer onto the preferred polymeric support may be used as a substitutent for a lead foil.
  • any of the conventional binders as those used for the dispersion of phosphors in layers of intensifying screens may be used herein.
  • Such binders include e.g. polyvinyl butyral, polyvinyl acetate, urethane, polyvinyl alcohol, polyester resins, polymethyl methacrylates and the like, and more preferably use is made therefor of binders selected from the group consisting of polyvinyl butyral, polyvinyl acetate, urethane, polyvinyl alcohol, polyester resins and polymethyl methacrylates.
  • the binders are mixed with a suitable solvent and conventional wetting agents as dispersion aids of the lead oxide therein.
  • the level of binder present should be kept low versus the dispersed lead oxide in order to provide a thin substrate coated with lead.
  • a support provided with an elastomeric layer thereupon, having a metal-containing filler therein, may be used.
  • an aluminum layer may be used coated with a layer of poly(vinylidene fluoride-hexafluoropropylene) copolymer having a metal-containing filler, such as lead oxide, dispersed therein.
  • a metal-containing filler such as lead oxide
  • a lead salt may be used, said salt being selected from the group consisting of lead carbonate, lead acetate, lead iodide, lead chloride, lead fluoride, lead sulfide, lead sulfate and lead nitrate.
  • Lead-based paint may be used and applied by the well known coating techniques, as e.g. silk screen printing, in order to provide an embossed layer, whereupon the needle-shaped phosphor may be deposited.
  • Substates such as glass panes or polymeric supports, all of them suitably cleaned, may, in the alternative, be subjected to magnetron sputtering procedures from a series of target cathodes, wherein the amount of each sputter coated material may be controlled by varying the number of cathodes beneath which the supports are passed during the coating operation.
  • a layer of lead oxide from a lead cathode operating in an oxygen-argon environment may so be deposited to an approximate thickness of about 50 Angstroms. For all other exposures, more rich in energy, it is clear that a higher thickness of the absorbing layer is more preferred. Details about magnetron sputtering procedures can e.g. be found in
  • Sol-gel reactions have recently been used in order to prepare inorganic-organic composite materials.
  • This general reaction making use of hydrolysis and polycondensation of a metal alkoxide species, is preferably applied in order to provide a layer having lead oxide in the layer arrangement of the screen or panel of the present invention.
  • said binder containing the lead compound in the intermediate layer arrangement of the storage screen or panel of the present invention is a matrix of a polycondensation product of a metal alkoxide species.
  • Said reactions take place under the influence of a suitable catalyst as e.g. an acid, and a network is formed in the process.
  • said binder containing the lead compound is a matrix of an inorganic network of alkoxymetal substituted organic polymers or copolymers matrix. During the build-up of this inorganic network alkoxymetal substituted organic polymers or copolymers are also present in the reaction medium and also undergo the same polycondensation reaction as the hydrolyzed metal alkoxides and are also incorporated in the network. In a further embodiment according to the present invention said binder containing the lead compound is a matrix of an inorganic network of alkoxymetal substituted organic polymers or copolymers matrix.
  • ORMOCERS ORganically Modified CEramics
  • ORMOSILS ORganically Modified SILicates
  • CERAMERS Chemical Random Access Memory
  • the screen or panel according to the present invention is thus provided with an intermediate layer arrangement wherein said lead compound is an oxide or a hydroxide of lead metal, dispersed in a binder.
  • the phosphor screen or panel according to the present invention has a binder containing the lead compound in a layer comprising a cross-linked polymeric matrix, wherein said matrix is derived from a cross-linking agent selected from the group consisting of dialkoxysilanes, trialkoxysilanes, tetraalkoxysilanes, titanates, zirconates and aluminates; and a colloid of silica, and wherein said matrix comprises a colloid of an oxide or a hydroxide of lead metal.
  • the support may be coated with a hydrophilic layer comprising a cross-linked polymeric matrix, wherein said matrix is derived from a cross-linking agent selected from the group consisting of dialkoxysilanes, trialkoxysilanes, tetraalkoxysilanes or, in the alternative, titanates, zirconates and aluminates; and a colloid of silica, and wherein said matrix comprises a colloid of an oxide or a hydroxide of lead metal.
  • the amount of silica in the layer preferably is in the range from 1 up to 50 times the amount of cross-linking agent.
  • use is preferably made from N-trimethoxy-N,N,N-trimethyl ammonium chloride, 3-aminopropyltriethoxysilane; a mixture of dimethyl dimethoxysilane and methyl trimethoxysilane sold as Z-6070 by the Dow Corning Company and glycidoxypropyltrimethoxysilane, without however being limited thereto.
  • a phosphor screen or panel wherein said intermediate layer arrangement has a surface that has been subjected to embossing for forming a fine concavo-convex pattern.
  • a phosphor screen or panel wherein said phosphor is a binderless phosphor, having needle-shaped crystals.
  • a binderless stimulable phosphor screen or panel wherein said needle-shaped phosphor crystals are crystals of an alkali metal phosphor.
  • a binderless stimulable phosphor screen wherein said alkali metal phosphor is a CsX:Eu stimulable phosphor, wherein X represents a halide selected from the group consisting of Br, Cl and I.
  • Such a binderless phosphor screen according to the present invention can be prepared by vacuum deposition of the phosphor crystals on the substrate as well as by combining (mixing) the ingredients for the phosphor (phosphor precursors) and then evaporating this mixture in order to have the phosphor formed in situ during evaporation.
  • the phosphor in a binderless phosphor screen according to the present invention can be any stimulable phosphor known in the art.
  • the storage phosphor used in binderless phosphor screens phosphor is a binderless phosphor, having needle-shaped crystals and in an even more preferred embodiment said needle-shaped phosphor crystals are crystals of an alkali metal phosphor.
  • Very suitable phosphors are, e.g., phosphors according to the formula I : M 1+ X.aM 2+ X' 2 bM 3+ X' ' 3 :cZ wherein:
  • Highly preferred phosphors for use in a binderless phosphor screen of the present invention are CsX:Eu stimulable phosphors, wherein X represents a halide selected from the group consisting of Br, Cl and I.
  • said phosphors are prepared by a method comprising the steps of :
  • CsBr:Eu stimulable phosphor is used, wherein said phosphor is prepared by the method comprising the steps of :
  • the binderless screen is advantageously prepared by bringing the finished phosphor on the support by any method selected from the group consisting of thermal vapour deposition, chemical vapour deposition, electron beam deposition, radio frequency deposition and pulsed laser deposition. It is also possible to bring the alkali metal halide and the dopant together and depositing them both on the support in such a way that the alkali metal phosphor is doped during manufacturing the screen.
  • the deposition can proceed from a single container containing a mixture of the starting compounds in the desired proportions.
  • the method further encompasses a method for manufacturing a phosphor screen containing a CsX:Eu stimulable phosphor, wherein X represents a halide selected from the group consisting of Br, Cl and I comprising the steps of :
  • the invention moreover includes a storage phosphor panel manufacturing method or procedure comprising the steps of :
  • the invention further includes a method for producing a storage phosphor panel comprising the steps of :
  • the invention further includes a method for producing a storage phosphor panel comprising the steps of :
  • the screen or panel of the present invention moreover may include on top of the phosphor layer any protective layer known in the art. Especially suitable however for use are those protective layers disclosed in EP-Application No. 02100297, filed March 26, 2002; and EP-A's 1 316 969 and 1 316 970.
  • the radiation image storage panel comprises a protective coating characterized in that, besides a binder, the said protective coating comprises a white pigment having a refractive index of more than 1.6, more preferably a refractive index of more than 2.0, and even more defined, titanium dioxide, which is present in the said binder, optionally further comprising a urethane acrylate, and wherein said protective coating has a surface roughness (Rz) between 2 ⁇ m and 10 ⁇ m as disclosed in EP-A 1 318 525.
  • Rz surface roughness
  • the protective layer is composed of a polymeric compound selected from the group consisting of vinyl resins comprising moieties derived from esters of acrylic acid and vinyl resins comprising moieties derived from esters of methacrylic acid and, even more preferably, a thermoplastic rubber as disclosed in EP-Application No. 02 100 235, filed March 8, 2002.
  • the polymer further comprises at least one colourant, and more preferably, a colourant having same absorption characteristics with respect to stimulating radiation as the colourant deposited by chemical vapour deposition as described above.
  • a parylene layer is highly desired as moisture proof layer as has e.g. been described in EP-A's 1 286 362, 1 286 363 and 1 286 364.
  • poly(p-2-chloro-xylylene) poly(p-2,6-dichloroxylylene) and fluoro substituted poly(p-xylylene), MgF 2 , or a combination thereof.
  • chemical vapour deposition is a technique that can be applied when making use of those components, the said technique is advantageously applied in this case.
  • "Parylene" thereby particularly provides excellent moisture resistance, whereas MgF 2 offers excellent anti-reflecting properties.
  • the screen or the panel of the present invention can also have reinforced edges as described in, e.g., US-A-5 334 842 and US-A-5 340 661.
  • the surface of the phosphor layer (1) in a panel or screen of the present invention can be made smaller than the surface of the support (2) so that the phosphor layer does not reach the edges of the support.
  • Such a screen has been disclosed in, e.g., EP-Application No. 02100297, filed March 26, 2002.
  • the present invention moreover includes a method for exposing an object to X-rays comprising the steps of :

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Conversion Of X-Rays Into Visible Images (AREA)
EP03102343A 2002-08-02 2003-07-30 Ecran luminescent excitable comprenant une couche antidispersion Withdrawn EP1387366A3 (fr)

Priority Applications (1)

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EP03102343A EP1387366A3 (fr) 2002-08-02 2003-07-30 Ecran luminescent excitable comprenant une couche antidispersion

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EP02102090 2002-08-02
EP03102343A EP1387366A3 (fr) 2002-08-02 2003-07-30 Ecran luminescent excitable comprenant une couche antidispersion

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EP1387366A3 EP1387366A3 (fr) 2007-08-08

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1997866A1 (fr) * 2007-05-22 2008-12-03 Agfa HealthCare NV Phosphore de rayonnement d'image ou panneau scintillant

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5091928A (en) * 1989-08-24 1992-02-25 E. I. Du Pont De Nemours And Company Lead and lead oxide screens for use with x-ray films
JPH08114897A (ja) * 1994-10-13 1996-05-07 Japan Steel & Tube Constr Co Ltd 乾式ｘ線フィルム用増感紙
US20020041977A1 (en) * 2000-06-23 2002-04-11 Yasuo Iwabuchi Europium activated cesium bromide phosphor and radiation image storage sheet
US20020043627A1 (en) * 1998-06-26 2002-04-18 Agfa-Gevaert X-ray luminescent article offering improved film sharpness
JP2002139599A (ja) * 2000-10-31 2002-05-17 Konica Corp 放射線画像変換パネル

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0631908B2 (ja) * 1986-03-11 1994-04-27 コニカ株式会社 シランカツプリング剤を含有する放射線画像変換パネル

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5091928A (en) * 1989-08-24 1992-02-25 E. I. Du Pont De Nemours And Company Lead and lead oxide screens for use with x-ray films
JPH08114897A (ja) * 1994-10-13 1996-05-07 Japan Steel & Tube Constr Co Ltd 乾式ｘ線フィルム用増感紙
US20020043627A1 (en) * 1998-06-26 2002-04-18 Agfa-Gevaert X-ray luminescent article offering improved film sharpness
US20020041977A1 (en) * 2000-06-23 2002-04-11 Yasuo Iwabuchi Europium activated cesium bromide phosphor and radiation image storage sheet
JP2002139599A (ja) * 2000-10-31 2002-05-17 Konica Corp 放射線画像変換パネル

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
DATABASE WPI Week 198742 Derwent Publications Ltd., London, GB; AN 1987-296582 XP002223514 & JP 62 209398 A (KONICA KK) 14 September 1987 (1987-09-14) *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1997866A1 (fr) * 2007-05-22 2008-12-03 Agfa HealthCare NV Phosphore de rayonnement d'image ou panneau scintillant

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