DE602004005368T2 - Storage phosphor carrier, radiation image sensor and method of their preparation - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION

The The present invention relates to one for use in the medical field X-ray radiography suitable (illuminable) storage film and a method for the production such films.

GENERAL PRIOR ART

One well-known use of storage phosphors is in the Production of X-ray images to find. US-A-3,859,527 discloses a process for the preparation of x-rays with an illuminable phosphor incorporated in a foil disclosed. In pattern modulated incident X-ray radiation In the case of the film, the phosphor becomes the energy resulting from the X-ray image temporarily save. Some time after the irradiation is feeling Ray of visible light or an infrared ray of light the foil while stimulating the release of stored energy as Light, then the light detected and in a series of electrical Signals are converted, resulting in the generation of a visible Process picture. For this purpose, the phosphor must preferably much of the incident X-ray energy save and if possible emit little of the stored energy until it is excited by the scanning beam becomes. The phosphor should therefore in other words a possible have low spontaneous emission. This technique is called "digital radiography" or "computer-controlled Radiography ".

There the X-ray amplifier foils in the above-described radiographic systems used repeatedly, it is important to provide them with a suitable Cover layer to provide the phosphor layer before mechanical and to protect against chemical damage. This measure is especially important in x-ray radiographic films, often in one Scanning module - in the illumination of the stored energy takes place - be promoted and not in an enveloping way Cassette present, but used without protective container as such and be handled.

The with any radiography system based on a storage foil and thus also achieved with a digital radiographic system picture quality depends mainly from the structure of the memory film. In general, the rule that all the thinner a storage film at a predetermined absorbed amount of X-rays is, the better the picture quality will be. This means, the lower the binder / phosphor ratio a memory film, the better the achievable with this film Be image quality becomes. An optimal sharpness let yourself thus achieve with binder-free films. Such a film can e.g. be prepared by the phosphor material by physical Vapor deposition, e.g. by thermal evaporation, sputtering, evaporation by electron beams or any other technique, onto a substrate is applied. Of course, this manufacturing process can not for the Production of high quality films with any available Phosphor be applied. The best results ensure that said manufacturing method using phosphor crystals with high crystal symmetry and simple chemical composition.

Of the Use of alkali metal halide phosphors in memory foils is one of the specialists in the field of storage phosphor radiology well known and the high crystal symmetry of these phosphors allows the production of structured films and binder-free Films.

Out The literature is known to be useful in the production of binderless It is advantageous for films with alkali halide phosphors to be the phosphor crystal in the form of stacks, needles, tiles, etc., to be deposited later Use of such a film to increase achievable image quality. Made of e.g. US Pat. No. 4,769,549 discloses the image quality of a binder-free memory film improve by the phosphor layer in Shape of a block structure is designed with fine columns. In e.g. U.S. Patent No. 5,055,681 discloses an alkali halide phosphor having a stacked structure containing memory sheet disclosed. To optimize the picture quality is further EP-A 1 113 458 discloses a storage film with a vapor-deposited CsBr: Eu phosphor layer, in which the phosphor in the form of fine, separated by cavities Needles present is.

Unfortunately, such acicular phosphors are quite brittle and often have physical damage to the imaging plates after just a few cycles in the scanner. It has been proposed to reinforce the films or screens by applying a protective layer to the evaporated phosphor layer. Such a protective cover layer is described in EP-A 0 392 474. A memory film with a very useful protective layer of a fluororesin and an oligomer and with a polysiloxane structure is described in EP-A 0 579 016. Furthermore, the application of a radiation-curable coating to form a protective cover For example, the protective layer contains a UV-cured resin composition consisting of monomers polymerized by radical polymerization by means of a photoinitiator and / or Prepolymer is composed. The monomeric products are preferably solvents for the prepolymers used. The impregnation of storage phosphor layers with a polymeric material, such as a thermosetting resin, is described in EP-A 0 288 038.

In EP-A 1 316 969 discloses a binder-free illuminable storage film discloses a carrier comprising a vapor deposited phosphor layer and one on the phosphor layer applied protective layer, characterized in that the vapor-deposited Fluorescent acicular is, the phosphor needles a length L and cavities between have the needles and the protective layer around the cavity Factor of at least 0.10 × L fills. This will change the film thickness increased, as well as by adding polymeric compounds, the the cavities partially fill, as described in EP-A 1 347 460. From other technological fields, such as. Production systems for ceramic products, e.g. the use of polymers of the Polysilazane-type prove because and because these polymers e.g. porous Impregnate ceramic materials, as described in US-A 5,459,114, and the mechanical strength increase the ceramic products.

in view of the picture quality has been disclosed in US-A 4,947,046 that the voids between Needle luminescent substances by colorants, dyes and / or pigments filled can be and bring about an improvement in image quality.

photostimulable Fluorescent materials or storage phosphor materials, such as Alkali halide phosphors are known to have a very high susceptibility across from Moisture, whereby the absorption of moisture from the Ambient air the properties of the phosphor and also the resolution or sharpness of the picture. Therefore, it is very desirable the top of the phosphor layer with a moisture resistant, for water to coat the impenetrable barrier layer and thus the phosphor to protect against moisture (and physical damage), e.g. in US Pat. No. 5,466 947, in which an illuminable phosphor with a Parylene polymer thin protective layer attached by plasma deposition coated for that ensures that the sensitivity of the memory film to low-level radioactive Labels are not affected becomes. In a radiation detector, such a moisture-sensitive Phosphor layer on an imaging device or a plate optical fiber, the optical fiber disk is known as an optical component, which is bundled from a variety constructed of optical fibers, that of the phosphor layer side here on the bundle incident radiation in after stimulation of the storage phosphor it is very desirable to convert both the phosphor particles to be detected as the layer in which the phosphor particles are contained to protect, especially with regard to image sharpness.

TASKS AND SHORT PRESENTATION THE PRESENT INVENTION

task The present invention is to provide one for use in an X-ray recording system usable illuminable storage foil that is moisture resistant and thus image quality loss prevented.

task In particular, the present invention provides a for the the same purpose usable binder-free illuminable memory film, where the film is moisture resistant and thus image quality loss prevented.

Be solved the above objects by providing an illuminable A storage film having the specific characteristics defined in claim 1. Specific characteristics for preferred embodiments The present invention is described in the subclaims.

Further Advantages and embodiments The present invention will become apparent from the following description seen.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

It has now been found that adequate resistance to ambient humidity of an illuminable storage sheet, and in particular a binderless, illuminable storage sheet comprising a radiation-transmissive substrate and a needle-shaped illuminable light produced on the substrate is obtained by coating the phosphor layer with a first light-transmissive organic cover film and then with a second transparent, attached to the first light-transmitting organic film outer film, wherein as the second light-transmitting film, a film of a silazane-type or siloxazane-type polymer suitable is. In a preferred embodiment of the invention, the second translucent film is a polymeric film compatible with polymers selected from the group consisting of silazane type and siloxazane type polymers, mixtures thereof, and mixtures of the silazane type or siloxazane type polymers contains film-forming polymers.

Siloxazane polymer types useful for this purpose have been known for some time. For example, US-A-3,271,361 discloses a process for preparing ordered siloxazane polymers and GB-A 1 084 659 discloses improvements in organosilicone polymers or improvements achieved with such polymers. A recent publication is PCT patent application WO 87/05298, which describes polysilazanes and related compositions and also methods and applications. The latter invention also relates to the use of polysiloxazanes and polyhydride siloxanes as ceramic precursors and mentions the hardness, strength and dimensional stability under extreme environmental conditions as well-known advantages of these compounds. The control of polysilazane molecular weight, structural composition and viscoelastic properties plays a very important role in determining the moldability (solubility, fusibility or malleability) of the polymer, in the yield of the ceramic product, and in the selective selection of a polymer for manufacture specific ceramic products. In particular, moldability plays an important role in determining the utility of a given polymer as a binder, as well as in shaping shapes and compositing coatings, spinning fibers, and the like. As the degree of crosslinking of a polymer increases, the controllability of the viscoelastic properties of the polymer decreases. Highly crosslinked and low molecular weight polymers are thus not particularly useful for spinning fibers and indeed because the spun preceramic fiber is often not tensile strength and therefore can not bear their own weight. The use of high molecular weight, substantially straight-chain polymers in the fiber, however, is therefore extremely important. Indeed, such polymers represent a significant advance in the art because they introduce the principle of chain linkage interactions into the fiber spinning process, thereby achieving an improvement in the overall tensile strength of the spun fibers. "Silazanes" are compounds containing at least one silicon-nitrogen bond, while "polysilazanes" include both oligomeric and polymeric silazanes, ie, compounds containing at least two monomeric silazane units. "Siloxazanes" are compounds containing the [O - Si - N] moiety, and the term "polysiloxazane" includes both oligomeric and polymeric siloxazanes, ie, compounds containing at least two monomeric siloxazane moieties. Thus, ceramic materials are provided which can be used in certain applications, including coatings for a variety of substrates. By way of example, a substrate may be provided with silicon nitride and silicon oxynitride coatings using a variant of the pyrolysis process just described. In this case, a substrate whose selection is made to be resistant to the high pyrolysis temperatures (eg, metal, glass, ceramic, fibers, and graphite) is coated with a preceramic polymer material by immersing it in a selectively selected silazane or siloxazane polymer solution or coated with such solution, sprayed or coated according to a similar technique, wherein the solution for most applications a predetermined ratio between preferably about 0.1 wt .-% and 100 wt .-%, particularly preferably between about 5 wt. -% and 10 wt .-% has. Prior to its application to the substrate, the liquid or dissolved polymer may be admixed with ceramic powders such as silicon nitride or silicon carbide, which may themselves be mixed with sintering additives such as alumina, silica, yttria and the like. Further, crosslinking agents can be added to the coating mixture, for example, because siloxane oligomers or siloxane polymers such as [CH ₃ SiHO] _x can be reacted with ammonia or amine, thereby introducing nitrogen groups into these oligomers or polymers. These reactions may lead to the formation of a nitrogen-crosslinked polymer with a homogeneous distribution of Si-O and Si-N bonds in the polymer. The siloxazane thus obtained can be pyrolyzed under inert gas atmosphere, such as under nitrogen or argon atmosphere, or under ammonia or Amingasatmosphäre to obtain siliciumoxynitridhaltige ceramic mixtures. In an alternative embodiment, silicon oxynitride is obtained directly by pyrolysis of oligomeric or polymeric starting materials based on nitrogen-free siloxane under an ammonia or amine gas atmosphere. In the latter case, the nitrogen is introduced into the siloxane rather than before pyrolysis. The siloxane may be a sesquisiloxane, a polyhydride siloxane, a crosslinked polysiloxane, or a polysiloxane having latent reactive groups such as hydrogenamine, alkoxy, sulfide, alkenyl, alkynyl, etc., wherein the latent reactive groups crosslink during heating or during the heating Curing can be replaced. The process for producing silicon nitride containing in the above-mentioned PCT patent application ger coatings can be carried out by means of a conventional oven.

Further the process allows the production of heat-resistant, wear-resistant erosion resistant, more resistant to abrasion and corrosion ceramic coatings based on silicon nitride. Thanks to the extremely high Hardness and Durability of silicon nitride has the coating process a wide field of application. The by the present invention procured preceramic polymers to which ceramic powders are added are, can for the production of three-dimensional articles by injection molding or Molding presses are used. A system of preceramic polymer and ceramic powder with advantage for the production of three-dimensional body through Insert molding presses.

In another application in particular, substantially straight chain high molecular weight polysilazanes be used for spinning pre-ceramic fiber. As further application areas are infiltration and impregnation processes to name, as discussed in e.g. US-A 4,177,230 and to W.S. Coblenz et al. in "Emergent Process Davis et al. (Plenum Publishing, 1984). As a rule, two general methods are used. at a first method is a high vacuum technique, in the one porous ceramic body under vacuum with a liquid or dissolved preceramic polymer is brought into contact. After infiltration Under high vacuum, the article will increase the article density pyrolyzed. The second method is high pressure infiltration. Furthermore can low molecular weight oligosilazane solutions with higher Agility in the porous ceramic body together with this ceramic body and a transition metal catalyst stored in the heating cabinet, after which a hardening of the oligomeric reagents follows. An in-situ chain extension or in-situ networking becomes the agility and volatility reduce the oligomeric starting materials.

As described in US Pat. No. 5,459,114, the delamination (exfoliation) of fibers is kept to a minimum by an in this US application prepared polysilazane, such as an inorganic polysilazane, an inorganic polysiloxazane, a polyorgano (hydro) silazane modified polysilazane or a polymetallosilazane, before or after the process of impregnation, hardening and chemical vapor deposition by chemical vapor deposition (CVD) is applied.

New polysiloxazanes containing [(SiH ₂ ) _n NH] and [(SiH ₂ ) _m O] as major structural units are provided in US-A 4,869,858. The object of this US application was to provide a simple process for producing silicon oxynitride-based continuous filaments. The polysiloxazanes are prepared by reacting a dihalosilane or its adduct with a Lewis acid, ammonia, and water vapor or oxygen. From the polysiloxazane, novel silicon oxynitride molds containing silicon, nitride (at least 5 mol%) and oxygen (at least 5 mol%) as main ingredients can be prepared.

In the more recent US application 6 210 786 will be a structure of a fiber reinforced Ceramic matrix composite (FRCMC) with appropriate physical Properties provided, wherein the structure is a ceramic Polymer derivative resin in its ceramic form and further in the ceramic resin containing embedded fibers in an amount that sufficient to give the structure a desired, with varying percentage Fiber volume to give varying degree of extensibility, the Fibers with a composite material different, between the fibers and the composite applied to the fibers Interface coating are provided.

In the even more recent U.S. Application 6,368,663 will be a composite element ceramic-based with one on a surface of a shaped fabric generated dense matrix and a matrix with in a column of Matrix provided fine cracks. Because of the weak Bonding force of the ceramic fiber through the matrix with fine Cracks forms a soft structure, the elastic modulus (the Young's modulus) reduced, the thermal stress mitigated and the resistance across from Thermal shocks improved. In addition, in this US invention a Method for producing a ceramic-based composite element provided in the first by a CVI treatment (Chemical Vapor Infiltration, i.e. chemical Gas phase infiltration) a SiC matrix on a surface of a formed tissue and then by a PIP treatment (Polymer Impregnation and Pyrolysis, i.

Polymer impregnation and pyrolysis), a column in the dense matrix is infiltrated with an organic silicon polymer and then the matrix is pyrolyzed. The process according to the invention is a process (hereinafter referred to as hybrid process) consisting of a combination of the CVI and PIP processes, wherein the CVI treatment forms a dense matrix around a ceramic fiber and the column is formed by the PIP treatment of the matrix is infiltrated and filled. In addition, the matrix formed by the hybrid treatment is referred to as a hybrid matrix. The PIP treatment (Polymer Impregna tion and pyrolysis, ie, polymer impregnation and pyrolysis) has a faster matrix formation rate compared to the CVI process and can be repeated over a short period of time. For this reason, the column existing after the CVI process is well filled by repeating the PIP process and the hermetic properties can be improved.

One Carbon / carbon composite, consisting of in one low ratio substantially evenly over both the inner surfaces as outer surfaces of the Composite of distributed crystalline silicon carbide, as well a method of making the composite and the insert of the composite are described in US Pat. No. 6,376,431. In this US application was discovered by using small amounts evenly over the Carbon / carbon composite distributed crystalline Silicon carbide a reduction of wear with no change or achieved only a slight increase in the coefficient of friction becomes.

The Contains phosphor layer usually a binder and an illuminable dispersed therein Phosphor. However, a phosphor layer is also known, an agglomerate of an illuminable phosphor without a binder contains. The binderless phosphor layer can be formed by a deposition process or baking process are formed. Also known is one Phosphor layer, which is an agglomerate of one with a polymeric Material impregnated contains illuminable phosphor. Any of the above Can contain radiation image storage film containing phosphor layers in the process of recording and reproducing a ray image be used.

The Luminescent layer can by coating a dispersion, the phosphor particles and a polymeric binder in a suitable organic solvent contains be generated. The binding polymer and the illuminable phosphor particles are usually in a relationship between 1: 1 and 1: 100 (binder: phosphor weight ratio), preferably between 1: 8 and 1:50 (weight ratio) in the coating dispersion contain. Usable as inventively Binder polymer is a variety of known resins in question. The dispersion can on the permanent carrier are applied and thus directly on the phosphor layer form. The dispersion can also be temporary carrier are applied and form a phosphor layer film thereon, then the temporary carrier peeled off and adhered to the permanent support. In the latter Technique can use the slide for the phosphor layer under heating be pressed in a known manner on the permanent support. The Strength and the material type of the carrier are also known and can optionally precise set or specifically selected become. The carrier can be provided with auxiliary layers, such as an adhesive layer and a light-reflecting layer become. The strenght the phosphor layer is usually between 20 μm and 1 mm, preferably between 50 microns and 500 μm. The process called steps of peeling off the protective film from the multilayer continuous film (comprising a coated layer, e.g. a fluororesin layer, a translucent resin film, an adhesive layer and contains a protective layer) and adhering the multilayer film to the storage sheet may include, in a system where the multilayer continuous film to be wound around a roll. Immediately after unwinding the continuous film from the roll becomes the protective film by means of the separating rolls subtracted and becomes an overlay obtained on the storage film endless film, which the exposed surface in contact with the surface the phosphor layer can come. Subsequently, the multilayered Continuous film and the storage film together through the laminating rollers guided and both films are laminated together. Is that too applied layer provided with the protective film, so this is Film removed after the above lamination step. In the method described above for producing a multilayer endless film, wherein the series after an adhesive layer, a translucent resin film layer and a coated resin layer on the phosphor layer of the storage film are attached, the multilayer film is then in as a radiation image storage film Serving individual pieces cut to a predetermined size.

At the Use of a binder-free phosphor layer, the phosphor by vapor deposition is also shown below Text to understand that a phosphor by any method from the group consisting of thermal vapor deposition Process, chemical vapor deposition, vapor deposition by electron radiation, radio frequency separation and Pulslaseraufdampfung is deposited on a substrate. This vapor deposition is preferably carried out under the conditions described in EP-A 1 113 458. Contain vapor-deposited phosphor layers by means of cavities separate phosphor needles, as described in e.g. EP-A 1 113 458, such is the phosphor layer, as stated above, quite sensitive to ambient humidity.

It has now been found that the inventive illuminable storage film in which a first light-transmitting organic film layer with a second translucent, on the first lichtdurchlässi organic film-applied film of a silazane or siloxazane-type polymer is coated, ensures proper and excellent protection of the film against ambient moisture. The second translucent polymer film thus contains polymers from the group consisting of polymers of the silazane and siloxazane type, mixtures thereof and mixtures of polymers of the silazane and siloxazane type with compatible film-forming polymers.

The chosen polymeric compounds of the silazane or siloxazane type can be described in any suitable solvent, e.g. Alcohols, such as methanol, ethanol, n-propanol, methoxypropanol and n-butanol, chlorinated hydrocarbons such as methylene chloride and Ethylene chloride, ketones such as acetone, butanone, methyl ethyl ketone, Diethyl ketone and methyl isobutyl ketone, esters of alcohols with aliphatic Acids, like Methyl acetate, ethyl acetate and butyl acetate, ethers such as dioxane, ethylene glycol monoethyl ether, Methyl glycol, aromatic hydrocarbons such as toluene, and Mixtures of the above solvents, solved become.

At the in a binder-free invention Memory Foil used storage phosphor can be a Any known to those skilled in the phosphor act. Preferably but is the one used in such a binderless memory film Phosphorus is an alkali metal phosphor.

Suitable phosphors are, for example, phosphors of the formula I. M ¹⁺ X · aM ²⁺ X _'2 bM ³⁺ X'_'3: cZ in the:
M ^{1+ denotes} Li, Na, K, Cs and / or Rb,
M ²⁺ Be, Mg, Ca, Sr, Ba, Zn, Cd, Cu, Pb and / or Ni,
M ³⁺ Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Bi, In and / or Ga,
Z represents Ga ¹⁺ , Ge ²⁺ , Sn ²⁺ , Sb ³⁺ and / or As ³⁺ ,
X, X 'and X "may be the same or different and each represents a halogen atom from the group consisting of F, Br, Cl, I and
0 ≤ a ≤ 1.0 ≤ b ≤ 1 and 0 <c ≤ 0.2.

Such Phosphors are described in e.g. US Pat. No. 5,736,069.

• – Versetzen des CsX mit zwischen 10^–3 und 5 mol-% einer Europiumverbindung aus der Gruppe bestehend aus EuX'₂, EuX'₃ und EuOX', wobei X' ein Element aus der Gruppe bestehend aus F, Cl, Br und I ist,
• – Erhitzen des Gemisches auf eine Temperatur über 450°C,
• – Abkühlung des Gemisches und
• – Zurückgewinnung des CsX:Eu-Leuchtstoffes.

Very particularly preferred storage phosphors for use in a binder-free storage film according to the invention are illuminable CsX: Eu phosphors in which X is a halide from the group consisting of Br and Cl and a Br / Cl combination and prepared by a process comprising the following steps become:

• - Adding the CsX with between 10 ^-3 and 5 mol% of a europium compound from the group consisting of EuX ' ₂ , EuX' ₃ and EuOX ', wherein X' is an element selected from the group consisting of F, Cl, Br and I. .
• Heating the mixture to a temperature above 450 ° C,
• - Cooling of the mixture and
• - Recovery of the CsX: Eu phosphor.

In a most preferred embodiment of the present invention The invention relates to the in the ausluchtbaren storage film used phosphor around a needle-shaped vapor-deposited CsBr: Eu phosphor. Since the storage film has a needle-shaped vapor-deposited CsBr: Eu phosphor contains, used it is preferable to use polymers which do not attract hydrophilic moisture Contain substituents. The selected polymeric compounds of the silazane or siloxazane type for use as an outer film on one vapor-deposited acicular CsBr: Eu phosphor containing Fluorescent screen are preferably in a solvent that easily anhydrous, dissolved, taking under "anhydrous" solvent a solvent with a water content of less than 1% by weight.

Furthermore, a polymeric compound of the silazane or siloxazane type may also be applied in the cavities between the needle-shaped phosphors in a vapor-deposited memory film according to the invention, before subsequently coating the phosphor layer with a protective layer. In this case, to fill the voids between the acicular phosphors, a solution whose viscosity allows the coating solution to drop into the voids between the acicular phosphors may be used. When filling the cavities, therefore, the viscosity of the coating solution is preferably adjusted so that the cavity is filled with the use of phosphor needles with a length L at least by a factor of 0.10 × L or 10% of the length through the protective layer. If the cavities are filled deeper, then the phosphor will not be so easy to recycle afterwards. It has now been found that a very acceptable compromise between on the one hand the strength of the phosphor layer and on the other hand a smooth recycling or recovery of the phosphor is achieved by the viscosity of the protective layer to a value that allows the cavities when using Fluorescent needles with a length L at least by a factor of 0.10 × L, is set.

Although when using an illuminable memory film according to the invention with acicular phosphor through computer-aided Radiography already a very high image quality can be achieved, it has been found that by using a colorant, i.a. one the excitation light absorbing dye or pigment, in the voids between the phosphor needles image quality is further increased. A further improvement is achieved by putting in the cavities except one the absorbance-absorbing colorants are also a colorant, that by the illuminable phosphor at its excitation reflected light is used. When using a Alkalimetallleuchtstoffes in the phosphor screen according to the invention is as excitation light either red light or infrared light is used and is the colorant preferably a blue colorant. As colorants come both organic colorants as inorganic colorants in question. to Use in the jet image storage film according to the invention suitable organic colorants with a blue and green lying body paint are u.a. ZAPON FAST BLUE 3G (manufactured by Hoechst AG.), ESTROL BRILL BLUE N-3RL (manufactured by Sumitomo Kagaku Co., Ltd.), SUMIACRYL BLUE F-GSL (manufactured by Sumitomo Kagaku Co., Ltd.), D & C BLUE No. 1 (manufactured by National Aniline Co., Ltd.), SPIRIT BLUE (manufactured from Hodogaya Kagaku Co., Ltd.), OIL BLUE No. 603 (manufactured by Orient Co., Ltd.), KITON BLUE A (manufactured by Ciba Geigy AG.), AIZEN CATHILON BLUE GLH (manufactured by Hodogaya Kagaku Co., Ltd.), LAKE BLUE A.F.H. (manufactured by Kyowa Sangyo Co., Ltd.), RODALIN BLUE 6GX (manufactured by Kyowa Sangyo Co., Ltd.), PRIMOCYANINE 6GX (manufactured by Inahata Sangyo Co., Ltd.), BRILLACID GREEN 6BH (manufactured by Hodogaya Kagaku Co., Ltd.), CYANINE BLUE BNRS (manufactured by Toyo Ink Co., Ltd.), LIONOL BLUE SL (manufactured Toyo Ink Co., Ltd.) and the like. As an advantageous use in the jet image storage sheet according to the invention suitable inorganic colorants with a blue and green lying body paint are ultramarine blue, cobalt blue and coelin blue. Further Usable colorants are those of BASF AG, Germany, under the Trademark HELIOGEN BLUE distributed blue colorants and those of Bayer AG, Germany, under the trademark MACROLEX BLUE blue colorant.

The colorant contained in the hollows of a storage film according to the invention and intended for reflecting the emitted light is preferably a white pigment. Examples of very suitable white pigments include, but are not limited to, TiO ₂ , ZnS, Al ₂ O ₃ , MgO and BaSO ₄ . A preferred white pigment for use in a storage film of the invention is TiO ₂ in its anatase crystal form.

The colorant (s) may be applied to the cavities either before the addition of, for example, the silazane or siloxazane type polymeric compound as described above, or together with the silazane or siloxazane type polymeric compounds. When the colorant is applied in the voids before the addition of the polymeric compound, the compound may be disposed in the fine gaps whose width is preferably between 1 μm and 30 μm. The substance of fine particles with a diameter of a few hundred nanometers can be mechanically inserted into the gaps without prior treatment. Using a lower melting point substance, it can be heated first and then inserted into the gaps. The substance may be dissolved or dispersed in a liquid of suitable viscosity and thus penetrate into the column in dissolved or dispersed form and is applied by vapor phase deposition or by heating modified form. The substance can be introduced into the column by vapor deposition. In the latter case, a suitable pigment is a dye as used in dye transfer by thermal sublimation. Typical and specific examples of dyes for use in dye transfer by thermal sublimation are described, for example, in EP-A 0 209 990, 0 209 991, 0 216 483, 0 218 397, 0 227 095, 0 227 096, 0 229 374, 0 235 939 , 0 247 737, 0 257 577, 0 257 580, 0 258 856, 0 400 706, 0 279 330, 0 279 467 and 0 285 665, US Pat. No. 4,743,582, US Pat. No. 4,753,922, US-A 4,753,923, US-A 4,757,046, US-A 4,769,360, US-A 4,771,035 and US-A 5,026,677, JP-A 84/78894, JP-A 84/78895, JP-A A 84/78896, JP-A 84/227490, JP-A 84/227948, JP-A 85/27594, JP-A 85/30391, JP-A 85/229787, JP-A 85/229789, JP-A 85/229790, JP-A 85/229791, JP-A 85/229792, JP-A 85/229793, JP-A 85/229795, JP-A 86/41596, JP-A 86/268493, JP-A 86 / 268494, JP-A 86/268495 and JP-A 86/284 489. If the colorants are not applied by vapor deposition in the cavities between the phosphor needles, they can first be dissolved or dispersed in any suitable solvent and then in the cavities of an e According to the invention storage film are attached. In the following, the term "solution (s) of a colorant" encompasses both solutions and dispersions Examples of suitable solvents are, for example, lower alcohols, such as methanol, ethanol, n-propanol and n-butanol, chlorinated hydrocarbons, such as methylene chloride and ethylene chloride, ketones, such as acetone, butanone, methyl ethyl ketone and methyl isobutyl ketone, esters of lower alcohols with lower aliphatic acids, such as methyl acetate, ethyl acetate and butyl acetate, ethers, such as dioxane, Ethylene glycol monoethyl ether, methyl glycol, and mixtures of the above-mentioned solvents. If the storage film contains the preferred vapor-deposited CsBr: Eu phosphor, it is preferable to use solvents which can easily be kept anhydrous, as has already been suggested above. The term "anhydrous" is understood to mean that a solvent having a water content of less than 1% by weight is used, for which reason the solvents used are esters of lower alcohols with lower aliphatic acids, such as methyl acetate, ethyl acetate and butyl acetate, and toluene. prefers.

dispersed one the colorants in the solution, so preferably the average particle size of the colorant of the width the cavities customized. From US-A 4,947,046 it is known that the width of the cavities between Phosphor needles e.g. is between 0.01 .mu.m and 30 .mu.m.

In a preferred embodiment of the present invention to refill the cavities used polymeric solution furthermore, at least one colorant, whereby in a single step both the elasticity the film as the image quality by simultaneous insertion of a polymer and one or more colorants increased in the cavities can be.

The Illuminable according to the invention Contains storage foil So a radiation-transmissive Substrate, a (preferably acicular) illuminable, on the Substrate attached phosphor layer, a first translucent organic Film that covers the phosphor layer, and one second translucent, on the first translucent organic film formed film, characterized in that the second translucent Film is a polymeric film consisting of polymers from the group from silazane and siloxazane type polymers, mixtures thereof and mixtures from polymers of silazane and Siloxazan type with compatible film-forming polymers.

In a further embodiment contains the illuminable invention Memory sheet also between the substrate and the illuminable Inserted phosphor layer translucent organic intermediate film.

In a preferred embodiment the present invention is the organic film in independence of it, whether as a separate first organic film or as Interlayer together with the first organic film in the Layer arrangement of the illuminable storage film is present to a "parylene" film, i. one Polyparaxylylene film.

preferred Polymers for use as organic "parylene" film are poly (p-xylylene), poly (p-2-chloroxylylene), poly (p-2,6-dichloroxylylene) and fluorine-substituted poly (p-xylylene). Very particularly preferred polymers for use in the protective layer according to the invention are by vacuum deposition, preferably by chemical vapor deposition attached poly-p-xylylene films. A poly-p-xylylene has between 10 and 10,000 structural units, each structural unit one optionally substituted aromatic ring group. each Any substituent group may be the same or different and may be any inert, organic or inorganic, in usually substituted on aromatic rings group. Examples for such Substituent groups are an alkyl group, an aryl group, a Alkenyl group, an amino group, a cyano group, a carboxyl group, an alkoxy group, a hydroxyalkyl group, a carbalkoxy group and similar Groups, as well as inorganic ions, such as a hydroxyl group, a Nitro group, a halogen group and other similar groups that are used in the Can usually be substituted on aromatic rings. Especially preferred substituted groups are simple hydrocarbon groups, such as the lower alkyl groups, such as a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group and a halogen group, in particular a chlorine group, a bromine group, an iodo group and a fluoro group, as well as a cyano group and a hydrogen group.

Thus, as the simplest parylene, the commercially available di-p-xylylene composition marketed by Union Carbide Co. under the trademark "PARYLENE" is preferred. Thus, as compositions for the moisture-resistant protective layer covering the phosphor sheets or fluorescent screens, preference is given to the non-substituted "PARYLENE N", the monochloro-substituted "PARYLENE C", the dichloro-substituted "PARYLENE D" and "PARYLENE HT" (a fully fluorine-substituted version of PARYLENE N which offers heat resistance up to a temperature of 400 ° C in comparison with the other "parylens", and which is also resistant to ultraviolet radiation and has a moisture resistance which is approximately equal to that of "PARYLENE C" / see that of Guy Hall, Specialty Coating Systems, Indianapolis, and available on www.scscookson.com for "High Performance Coating for Electronics Resist Hydrocarbons and High Temperature"). Specialty Coating Systems, a Cookson company, also provides the "Technology Letters" issue, such as the article on "Solvent Resistance of the parylenes ", in which the effect of numerous organic solvents on the parylenes N, C and D is investigated.

All particularly preferred polymers for use in the above Preparation of the organic polymer film layer are poly (p-2-chloroxylylene), i.e. PARYLENE C-foil, poly (p-2,6-dichloroxylylene), i. PARYLENE D-foil, and "PARYLENE HT" (a fully fluorine-substituted Version of PARYLENE N).

Parylene is available through several companies and is typically used as a protective layer for printed circuit boards, sensors and other electronic and electrical equipment. Although the scope of the present invention does not include the specific manner in which the parylene is applied as a cover layer to the phosphor layer or, moreover, as an intermediate layer between the radiation-transmissive substrate and the phosphor layer, the parylene layer is preferably applied by chemical vapor deposition (US Pat. CVD). A suitable method for this purpose is disclosed in EP-A 1 286 364. The process of vapor deposition essentially comprises the following steps:

One suitable dimer, e.g. (Cyclodi (p-xylene) for the deposition of PARYLENE N, cyclodi (p-2-chloro-xylene) for the deposition of PARYLENE C or cyclodi (p-2,6-dichloroxylene) for the Deposition of PARYLENE D, is heated and splits in two Radicals on. These radicals are deposited on the phosphor layer, where they polymerize and form a polymeric layer. The Chemical vapor deposition of the layer of parylene (PARYLENE N, C or D) has several advantages because the barrier layer applied without pinholes and moreover not just on the main surface of the Luminescent layer, but also deposited at the edges and thereby ensuring a complete seal of the phosphor layer.

The Strength the parylene layer (s) is preferably between 0.05 μm and 15 μm, especially preferably between 1 μm and 10 μm.

When radiation transmissive Substrate for the illuminable invention Storage foil becomes a substrate of aluminum or a substrate made of amorphous carbon (a-C). Such a substrate of aluminum film or a film of amorphous carbon, preferably on a polymeric carrier is attached opened Perspective for making a binder-free illuminable Storage film on a support with low X-ray absorption, even if the storage phosphor layer is at fairly high temperatures is applied by vacuum evaporation. Usable according to the invention Films of amorphous carbon (a-C) are commercially available through e.g. Tokay Carbon Co., LTD, Tokyo, Japan, or Nisshinbo Industries, Inc, Tokyo, Japan, under the trade names "Glass-Like Carbon Film" or "Glassy Carbon".

The Strength the layer of amorphous carbon in a binder-free invention Storage film or a binder-free phosphor screen according to the invention can be between 100 μm and 3,000 μm, being to achieve a compromise between flexibility, strength and X-ray absorption one Strength between 500 μm and 2,000 μm is preferred.

Very high mechanical strength is particularly required and desirable in radiography systems that use a flattenable imaging sheet that is automatically removed from the cassette during readout of the energy stored in the sheet, passed through a reading unit - often through a tortuous path - and then back is guided into the cassette. In such a reading unit, it is quite advantageous to use a film or screen having an auxiliary layer laminated thereon of amorphous carbon or aluminum, which polymeric subcarrier layer may be composed of any polymer film known to those skilled in the art, eg a polyester film, polyvinyl chloride, polycarbonate, syntactic polystyrene, etc. Preferred polymeric films are Polyester films such as polyethylene terephthalate films, polyethylene naphthalate films, etc. The thickness of the auxiliary layer may vary between 1 μm and 500 μm. It may be a fairly thin, eg 400 μm thin, amorphous carbon film with a 500 μm thick laminated polymeric film or a thick, eg 2000 μm thick, amorphous carbon film with a thin, eg 6 μm thin, laminated polymeric film be used. The relative strength of, on the one hand, the amorphous carbon or aluminum layer and, on the other hand, the polymeric carrier film may vary within wide limits and depends solely on the required physical strength of the amorphous carbon or aluminum during deposition of the phosphor layer and the flexibility required during practical use of the phosphor fluorescent screen.

Of the Use of a optionally coated with a moisture-resistant parylene layer radiolucent Substrate, one above applied binder-free storage phosphor layer (wherein for the Illuminable according to the invention Storage film a binderless needle-shaped, vapor-deposited CsBr: Eu phosphor preferred), a first light-transmitting organic film, preferably a moisture-resistant parylene layer covering the storage phosphor layer, and a second translucent, inorganic, attached to the first light-transmitting organic film Films of a silazane type or siloxazane type polymer impart the Memory film or the screen significantly improved Protection against moisture from ambient air.

In a preferred embodiment is the inventive ray image storage film thus characterized in that it is a radiation-transmissive substrate (wherein the radiation transmission especially desirable is for mammographic applications), one applied to the substrate binderless acicular Storage phosphor, optionally one between the substrate and the Inserted phosphor layer Interlayer, a first translucent, the storage phosphor layer covering organic film (preferably a "parylene layer", preferably - but without limited to this to be - with the same composition as the possible intermediate layer) and a translucent inorganic, attached to the first light-transmitting organic film Contains film of a polysilazane or polysiloxazane, wherein the imaging plate facing arranged an imaging device is. Such a layer arrangement described above confers the usually moisture-sensitive and scratch-sensitive Phosphor layer in an appropriate manner excellent resistance against moisture and scratch resistance, thus ensuring an efficient Maintaining the picture quality.

One inventive radiation image detector So includes an above-described illuminable storage film and one of the illuminable memory film facing arranged imaging device. In a preferred according to the invention embodiment For example, a radiation image detector comprises a lightable storage film and one of the illuminable memory sheet arranged facing Imaging device. In a preferred embodiment according to the invention the imaging device is a charge-coupled device Element (CCD).

The Method of producing such a storage film according to the invention is also characterized by the fact that it is the production steps a binderless acicular, on a radiolucent Substrate evaporated CsBr: Eu phosphor layer, the formation of a first translucent, the storage phosphor layer covering organic film and the formation of a translucent inorganic, at first translucent organic film attached film.

Optional an intermediate layer is applied, preferably with the same Composition like the first translucent organic film, and Although a jet image storage film with significantly improved moisture resistance to obtain the phosphor layer. It is clear that the herein described layers in a preferred embodiment the same preferred layers as described above.

• – Bildung einer ausleuchtbaren Leuchtstoffschicht auf einem strahlungsdurchlässigen Substrat,
• – Bildung eines ersten lichtdurchlässigen organischen, die Schicht aus nadelförmigem ausleuchtbarem Leuchtstoff bedeckenden Films und
• – Bildung eines zweiten lichtdurchlässigen Films auf dem ersten lichtdurchlässigen organischen Film, wobei der zweite lichtdurchlässige Film ein polymerer Film ist, der Polymere aus der Gruppe bestehend aus Polymeren des Silazan- und Siloxazan-Typs, Gemischen derselben und Gemischen aus Polymeren des Silazan- und Siloxazan-Typs mit vereinbaren filmbildenden Polymeren enthält.

The present invention further provides a method, characterized by the following steps, of manufacturing a luminescent imaging sheet having the above-described specific characteristics:

• Formation of an illuminable phosphor layer on a radiation-transmissive substrate,
• - Forming a first transparent organic, the layer of needle-shaped illuminable phosphor covering film and
• Forming a second translucent film on the first translucent organic film, the second translucent film being a polymeric film comprising polymers selected from the group consisting of silazane and siloxazane type polymers, mixtures thereof and mixtures of polymers of the sila zan and siloxazane type with compatible film-forming polymers.

In a preferred embodiment The manufacturing method described above is the organic film around a polyparaxylylene film.

In a preferred embodiment the production method of a jet image storage film according to the invention is characterized in that it takes as steps the formation of an optional one translucent organic film (preferably a parylene film) coated Storage phosphor layer (preferably by vacuum evaporation attached acicular Phosphor) on a radiation-transmissive substrate, the formation a first translucent organic, the storage film covering film (also with a parylene composition) and the formation of a translucent inorganic Films on the first translucent organic film comprises, characterized in that the second translucent Film is a film of a silazane type or siloxazane type polymer Further, wherein the storage film is further facing an imaging device is arranged.

Thereby, that the translucent inorganic film formed on the first light-transmissive organic film becomes a ray image detector in the present invention with a storage film with markedly improved moisture resistance produced.

• – Bildung einer nadelförmigen ausleuchtbaren Leuchtstoffschicht auf einem strahlungsdurchlässigen Substrat,
• – Bildung eines ersten lichtdurchlässigen organischen, die Schicht aus nadelförmigem ausleuchtbarem Leuchtstoff bedeckenden Films und
• – Bildung eines lichtdurchlässigen anorganischen Films auf dem ersten lichtdurchlässigen organischen Film, wobei der zweite lichtdurchlässige anorganische Film ein polymerer Film ist, der ein Polymer des Silazan- und Siloxazan-Typs enthält.

The present invention provides a method characterized by the following steps for producing an illuminable memory film:

• Formation of a needle-shaped illuminable phosphor layer on a radiation-transmissive substrate,
• - Forming a first transparent organic, the layer of needle-shaped illuminable phosphor covering film and
• Forming a transparent inorganic film on the first transparent organic film, wherein the second transparent inorganic film is a polymeric film containing a silazane and siloxazane type polymer.

• – Aufdampfung eines ausleuchtbaren Leuchtstoffes auf ein Substrat zur Bildung einer aus Leuchtstoffnadeln und Hohlräumen zwischen den Nadeln zusammengesetzten Leuchtstoffschicht,
• – Auftrag einer Polymerlösung auf den aufgedampften Leuchtstoff,
• – gegebenenfalls Abwischen des Überschusses an Lösung von der Leuchtstoffschicht (dieser Schritt entfällt bei Tauchbeschichtung, Aufsprühen, Stabbeschichtung und Siebbeschichtung) und
• – Trocknung der Speicherfolie.

The present invention further comprises a method characterized by the following steps of preparing a binderless acicular luminescent phosphor layer on a radiation transmissive substrate:

• Vaporizing an illuminable phosphor onto a substrate to form a phosphor layer composed of phosphor needles and voids between the needles,
• Application of a polymer solution to the vapor-deposited phosphor,
• If appropriate, wiping off the excess of solution from the phosphor layer (this step is omitted in the case of dip coating, spraying, bar coating and screen coating) and
• - Drying of the storage film.

• – Anordnen mehrerer beheizbarer Behälter, die CsX und eine Europiumverbindung aus der Gruppe bestehend aus EuX'₂, EuX'₃ und EuOX' enthalten, wobei X' F, Cl, Br, I oder ein Gemisch derselben ist, und des Substrats in einer Vakuumbedampfungskammer, die auf einen Druckwert von zumindest 10^–1 mBar entleert ist,
• – Abscheidung, gemäß einem Verfahren aus der Gruppe bestehend aus physikalischer Gasphasenabscheidung, chemischer Gasphasenabscheidung oder Zerstäubung, der CsX-Verbindung und der Europiumverbindung auf ein Substrat in einem solchen Verhältnis, dass sich auf dem Substrat ein mit zwischen 10^–3 und 5 mol-% Europium dotierter CsX-Leuchtstoff bildet,
• – Auftrag einer Lösung einer polymeren Verbindung des Silazan-Typs oder Siloxazan-Typs auf den aufgedampften Leuchtstoff und
• – Trocknung der Speicherfolie.

The present invention further includes a method of making a binderless acicular luminescent phosphor luminescent layer containing CsX: Eu phosphor on a radiation-transmissive substrate, wherein X is a halide selected from the group consisting of Br, Cl and a Br / Cl mixture the method is characterized by the following steps:

• - arranging a plurality of heatable containers 'include, where X' CsX and an Europium compound selected from the group consisting of EuX _'2, EuX' ₃ and EuOX F, Cl, Br, I or a mixture thereof, and the substrate in a deposition chamber which is deflated to a pressure of at least 10 ^-1 mbar,
• Deposition, according to a method of the group consisting of physical vapor deposition, chemical vapor deposition or sputtering, the CsX compound and the europium compound on a substrate in such a ratio that on the substrate one with between 10 ^-3 and 5 mol% Europium doped CsX phosphor forms,
• - Applying a solution of a polymeric compound of the silazane type or siloxazane type on the deposited phosphor and
• - Drying of the storage film.

• – Anordnen eines einen CsX:Eu-Leuchtstoff enthaltenden beheizbaren Behälters, wobei X Cl, Br oder ein Cl:Br-Gemisch ist, und des Substrats in einer Vakuumbedampfungskammer, die auf einen Druckwert von zumindest 10^–1 mBar entleert ist
• – Abscheidung, gemäß einem Verfahren aus der Gruppe bestehend aus physikalischer Gasphasenabscheidung, chemischer Gasphasenabscheidung oder Zerstäubung, des CsX:Eu-Leuchtstoffes zur Bildung einer aufgedampften Leuchtstoffschicht aus nadelförmigem Leuchtstoff,
• – Auftrag einer Lösung einer polymeren Verbindung des Silazan-Typs oder Siloxazan-Typs auf den aufgedampften Leuchtstoff und
• – Trocknung der Speicherfolie.

More particularly, the present invention includes a method of making a binderless acicular luminescent phosphor layer on a radiation transmissive substrate, the phosphor layer containing an illuminatable CsX: Eu phosphor and the method characterized by the steps of:

• Arranging a heatable container containing a CsX: Eu phosphor, wherein X is Cl, Br or a Cl: Br mixture, and the substrate in a vacuum evaporation chamber deflated to a pressure of at least 10 ^-1 mbar
• Deposition, according to a method of the group consisting of physical vapor deposition, chemical vapor deposition or sputtering, of the CsX: Eu phosphor to form a deposited phosphor layer of acicular phosphor,
• - Applying a solution of a polymeric compound of the silazane type or siloxazane type on the deposited phosphor and
• - Drying of the storage film.

Further, the storage sheet of the present invention may contain a second light-transmitting organic film on the transparent inorganic film of the storage sheet. This second light-transmitting organic film (preferably also here a parylene film) applied to the light-transmitting inorganic polysilazane or polysiloxazane film can prevent the light-transmissive inorganic film from peeling off, especially if, besides the polysilazane or polysiloxazane, inorganic ones are also used Particles such as SiO ₂ , Al ₂ O ₃ , TiO ₂ , In ₂ O ₃ , SnO ₂ , MgO, SiN, MgF ₂ , LiF, CaF ₂ and SiNO are included.

Thereby, that the first translucent organic film, preferably the same composition as the possible intermediate layer has, according to his order, the in a preferred embodiment, as for Parylene, by vapor deposition, cover the whole substrate can, is an excellent protection of the storage phosphor layer achieved against moisture.

The the following detailed description, for explanation only serves and therefore the present invention is not limited thereto further illustrate the present invention.

The Although the field of application of the present invention will be apparent to those skilled in the art from the above description as well as the description below However, it should be clear that specific descriptions, clearly indicating preferred embodiments of the present invention Invention, for explanation only and thus within the scope of the present invention different changes and modifications possible are.

A surface an aluminum substrate in the storage film is preferably made a storage phosphor composed of a columnar structure, which is designed so that they incident radiation into visible Light converts. For this reason, it is preferable in this layer Eu-doped CsBr used.

All surfaces of the storage phosphor formed on the aluminum substrate as well as the substrate itself is coated with a first polyparaxylylene film (i.e. a first translucent organic film), the surface of this first polyparaxylylene film on the phosphor layer side of polysiloxazane film (translucent inorganic Movie).

For his part, The radiation image detector has a structure in which an imaging device attached to the storage film on the storage phosphor.

The Production of the storage film comprises the following preferred steps: on a surface of the aluminum substrate (1.0 mm thick) is left by vapor deposition columnar crystals of Eu-doped CsBr grow and the storage phosphor layer form. Due to its high moisture absorption that would the storage phosphor layer forming CsBr: Eu mixture by absorption of air vapor melt, if not the layer is protected against it. To prevent the Decomposition of the moisture-sensitive layer is by chemical Gas phase deposition (CVD) of the first polyparaxylylene film attached. For this purpose, the aluminum substrate, on the so already the needle-shaped phosphor is deposited in a CVD device inserted and in a strength of 10 μm coated with the first polyparaxylylene film. So it will be all surfaces the illuminable needle-shaped Phosphor layer and the aluminum substrate (at its no columnar acicular phosphor containing side) with the first Polyparaxylylenfilm coated. Characterized in that the tip portion of the columnar acicular storage phosphor has an uneven shape, the first polyparaxylylene film is used also as a flattening layer for the tip portion of the columnar acicular storage phosphor layer.

Subsequently, the first polyparaxylylene film on the storage phosphor side is coated by spraying with a polysiloxazane film having a thickness of about 10 μm. Because with the polysiloxazane film the Scratch resistance of the storage phosphor layer aims to improve, it is mounted in a storage phosphor layer covering area. This step is the final step in the manufacturing flowchart of the storage phosphor.

Further the beam image detector is made by e.g. a charge coupled Element (CCD) as an imaging device on the storage phosphor layer side attached to the storage foil.

When Substrate in the above-mentioned preferred embodiment While an aluminum substrate is used, it is clear that that any substrates with a favorable X-ray permeability come up, come into question. It can So also substrates of amorphous carbon (a-C), substrates graphite carbon, beryllium substrates, silicon carbide substrates and the like can be used.

Further Although the Polysiloxazanfilm in the above-mentioned embodiment on the storage phosphor side on the surface of the first polyparaxylylene film, expediently but not only on this surface side of the storage film, but also about the whole surface of the first polyparaxylylene film.

In the above mentioned embodiments includes this as preferred according to the invention organic film used polyparaxylylene not just polyparaxylylene, but also polymonochlorparaxylylene, polydichlorparaxylylene, Polytetrachlorparaxylylene, polyfluoroparaxylylene, polydimethylparaxylylene and polydiethylparaxylylene, but without being limited thereto.

In The present invention describes a method which has a additional Comprises step of forming a third translucent film layer, wherein the third translucent film layer a second translucent one Film layer covering polymeric film is. To get thicker Overlays will this third translucent film layer also in a further embodiment of the present invention may be a polymeric film layer, the polymers from the group consisting of polymers of the silazane and siloxazane type, Mixtures thereof and mixtures of polymers of silazane and Siloxazan type with compatible film-forming polymers.

There the storage film of the present invention has a translucent inorganic Film on the first translucent organic film containing storage film can contain the moisture resistance the storage phosphor layer by coating this layer with one or more translucent inorganic films to a considerable extent be improved.

Further can or can this translucent (n) inorganic film layer (s) having an organic translucent outer film, which can prevent the translucent inorganic film after more frequent Use of the foil peel off, be coated.

The The present invention is illustrated in the examples below preferred embodiments of the invention however, it should be noted that the present invention not on these embodiments limited becomes.

EXAMPLES

Production of the storage foils

It become CsBr: Eu memory film layers by thermal vapor deposition manufactured by CsBr and EuOBr.

To CsBr is treated with EuOBr and the mixture is placed in a vacuum deposition chamber container filled. The phosphor is then applied to an aluminum substrate with a thickness of 1.5 mm and a circle diameter of 40 mm deposited.

Of the Distance between the container and the substrate 10 centimeters. While the evaporation is the substrate at a speed of 12 ppm turned.

Before the evaporation begins, the chamber is emptied to a pressure of 4.10 ^-5 mbar. During vapor deposition, Ar is introduced into the chamber as an inert gas.

It several films are produced, namely a suitable test material, on the several different techniques for applying a protective layer can be applied to obtain.

Parylene C is in accordance with a low temperature low pressure coating technique a storage foil attached. The dimer is chlorodiparaxylylene at 150 ° C evaporated and at 690 ° C decomposed into monomer form. The monomer vapor becomes the vacuum deposition chamber where the vapor polymerizes on the surface of the storage foil.

The Patterns are in a strength of 10 μm coated.

It becomes a solution of 20 g of Kion VL20 polysilazane from Kion Corporation, Columbus, Ohio, USA, in a solvent mixture made up of 30 g of toluene and 30 g of methyl ethyl ketone. To do this 10 g of a 30 wt .-% solution a copolymer of methyl methacrylate and butyl methacrylate. As thermoinitiator, 5 g of tert-butyl peroxy-2-ethylhexyl carbonate into the solution mixed, whereby a clear, colorless solution is obtained. The solution will be by dip coating on those provided with a parylene layer Memory film applied and then for 20 h at 90 ° C in a Drying oven dried. The hardened Polysilazane acrylate coating with high abrasion resistance is a clear, translucent and colorless layer (coating A) with a thickness of about 10 μm.

at In a second application (coating B), 2 g of a polysilazane are used dissolved in 10 g of toluene. This solution are 2 g of a 20 wt .-% solution of strong homogenization Dimethyl-2,2-azobis (2-methylpropionate) dropwise. After 30 minutes stir becomes the solution by bar coating on those provided with a parylene layer Applied memory film and dried at 120 ° C for 1 h.

The hardened Coating combines a high abrasion resistance, a high elasticity and a high light transmission.

For coating C, a polysilazane solution is used. For this purpose, 20 g of polysilazane are dissolved in 20 g of methyl ethyl ketone. To this solution are added 20 g Servocure RT184 from Servo, The Netherlands, and 20 g Ebecryl 1290 from UCB Radcure, Belgium. The solution is homogenized by stirring for 2 hours. Subsequently, 4 g of Darocur 1173 are added by Ciba, Germany. The paint is applied by screen printing and cured with intense UVA light with an intensity of at least 200 mW / cm ² .

at Another application (coating D) is a solution of Polysiloxazan and urethane acrylates on with a parylene layer provided memory foil sprayed and subsequently Hardened for 20 h under the action of atmospheric moisture at 60 ° C. It will be a 6 μm strong, abrasion-resistant, clear, non-brittle layer obtained.

The sprayed polymer solution is a mixture dissolved in 400 g of methyl ethyl ketone and 300 g of methoxypropanol from 7.5 g of poly (oxy-1,2-ethanediylhydro- (1-oxo-2-propenyloxy)) ether, 2.5 g of 2-ethyl-2- (hydroxymethyl) -1,3-propanediol, 5 g of hexanediol diacrylate, 15 g of a hexafunctional urethane acrylate oligomer and 60 g of Kion ML33 / C33 from Kion Corporation, Columbus, USA.

To the Avoiding cracking and irregularities in the order thick coatings due to shrinkage during curing of the coatings occur can, it is recommended that the thicker coatings in the form of a multilayer Apply arrangement (wherein the polysilazane precursor solutions in a double coating, triple coating or even even more layers are applied).

The Abrasion resistance of the coatings is in accordance with the standard ASTM D1044 with a with Calibrase CS10F elements, sandpaper P220 and a load of 250 g on each element equipped Teledyne Taber 5130 Abraser evaluated. The loss of layer mass is measured after 100 cycles.

To evaluate the resistance to humidity, the samples are stored for 1 week in a desiccator (desiccator) with a preset atmosphere of 87% relative humidity at 25 ° C. The gravimetric water absorption (expressed in mg) is observed in relation to the specific surface area (expressed in cm ² ). The results of both tests for films having the above-mentioned compositions are summarized in Table 1 below.

Table 1

Thus, it has clearly emerged that in the test according to the ASTM D1044 standard using a Teledyne Taber 5130 Abraser equipped with Calibrase CS10F elements, sandpaper P220 and a load of 250 g on each element, a mass loss of the surface layer of the present invention after 100 cycles Film of not more than 3 mg is determined. The simultaneously measured water absorption is not more than 0.20 mg / cm ² .

Out These results clearly indicate the appropriate durability against wear (scratch resistance) and moisture on the inventive binder-free storage film applied protective layer combination.

in the The above has thus been proven that memory foils with an excellent resistance against moisture at both the top and the edges of the Memory film can be produced in a radiation detector.

To the detailed description of preferred embodiments of the present invention Invention is likely It should be clear to the experts in this field that here within as defined in the following claims Scope of the present invention numerous modifications possible are.

Claims (10)

An illuminable storage film comprising: a radiation-transmissive substrate, an illuminable phosphor layer formed on the substrate, a first light-transmissive organic film covering the illuminable phosphor layer, a second light-transmissive film formed on the first light-transmissive organic film, characterized the second translucent film is a polymeric film containing polymers selected from the group consisting of silazane type and siloxazane type polymers, mixtures thereof, and mixtures of the silazane type or siloxazane type polymers with compatible film forming polymers. Illuminable storage sheet according to claim 1, which furthermore a translucent organic intermediate film between the substrate and the illuminable Contains storage foil. Illuminable storage film according to claim 1 or 2, characterized in that the organic film is a polyparaxylylene film is. Illuminable memory film according to one of claims 1 to 3, characterized in that the substrate is an aluminum substrate or a substrate of amorphous carbon (a-C). Illuminable memory film according to one of claims 1 to 4, characterized in that the storage phosphor is a binder-free, needle-shaped, vapor-deposited CsBr: Eu-phosphor is. A radiation image detector, which is an illuminable A storage film according to any one of claims 1 to 5 and one of the illuminable ones Contains imaging plate arranged facing imaging device. Radiation image detector according to claim 6, characterized in that the imaging device is a charge-coupled element (CCD) is. A marked by the following steps Method for producing an illuminable memory film according to one of the claims 1 to 5: - Education an illuminable phosphor layer on a radiation-transmissive substrate, - Education a first translucent organic, the layer of needle-shaped illuminable phosphor covering film and - Education a second translucent Films on the first translucent organic film, wherein the second light-transmissive film is a polymeric film is the polymer selected from the group consisting of polymers of silazane and siloxazane type, Mixtures thereof and mixtures of silazane and siloxazane type polymers containing compatible film-forming polymers, and the organic film is a polyparaxylylene film. Method according to claim 8, characterized in that that the procedure has an additional Comprises step of forming a third translucent film layer, the third translucent Film layer a the second translucent film layer covering is polymeric film. Method according to claim 9, characterized in that that the third translucent Film layer is a polymeric film layer, the polymers from the Group consisting of polymers of the silazane and siloxazane type, Mixtures thereof and mixtures of polymers of silazane and Siloxazan type with compatible film-forming polymers.