JP2005125764A - Scratch-resistant moisture protective parylene layer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To keep its moisture repellency or moisture protective characteristics by improving adhesive properties of an organic layer on a p-xylylene (parylene) layer to make a sheet or a foil containing a layer unit having the parylene layer scratch-resistant. <P>SOLUTION: In the sheet or the foil containing the layer unit divided into at least two layers, namely, a layer A being the p-xylylene (parylene) layer, and layers B existing on both sides of the layer A if necessary, it comprises an organic coating with at least one kind of phosphate compounds. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a solution for improving the adhesion between a parylene layer and an adjacent organic layer exhibiting excellent scratch resistance.

  In particular, the present invention relates to improved adhesion of the scratch resistant layer when the parylene layer is coated on a panel support.

  In particular, the present invention preferably comprises a phosphor sheet or panel having a highly moisture sensitive CsBr: Eu phosphor, said phosphor layer being coated with a moisture protective parylene layer coated thereon as a protective layer, And a method of manufacturing such a phosphor sheet or panel.

  A well-known use of phosphors is in the generation of X-ray images. In conventional radiographic systems, X-ray radiographs are obtained by X-rays which are transmitted image-wise through an object and converted into corresponding intensity light in a so-called intensifying screen (X-ray conversion screen), in which phosphorescence is obtained. Body particles absorb the transmitted X-rays and convert them into visible light and / or ultraviolet light. Photographic films are more sensitive to visible light and / or ultraviolet light than to direct impact of X-rays.

  According to another method for recording and reproducing X-ray patterns, for example as disclosed in US Pat. No. 3,895,527, a special type of phosphor known as a photostimulable phosphor is used, which is included in the panel. Exposure to an incident X-ray beam modulated according to the pattern, resulting in a temporary storage of the energy contained in the X-ray radiation pattern. At intervals after exposure, a beam of visible or infrared light scans the panel, stimulating the emission of stored energy as light. The light can be detected and sequentially converted into an electrical signal, which can be processed to produce a visible image. For this purpose, the phosphor should store as much of the incident x-ray energy as possible and release as little of the stored energy until stimulated by the scanning beam. This is referred to as “digital radiography” or “computer radiography”.

  For both types of radiographs, it is preferable to be able to select the phosphor to be used based on its speed and image quality without having to worry about hygroscopicity.

  It is therefore highly desirable to have the potential to produce water vapor impermeable phosphor panels even when used for direct radiography or computer radiography. US-A 4749933 discloses a radiation image storage panel having at least one stimulable phosphor layer on a support and a protective layer provided on the stimulable phosphor layer, wherein the protective layer comprises at least two layers. And their moisture content under 90% relative humidity on the adsorption isotherm at 25 ° C. differs by more than 0.5%. ADVANTAGE OF THE INVENTION According to this invention, the radiation image storage panel which has favorable moisture resistance and can be used for a long period of time is obtained. Although a protective layer as disclosed in US-A 4749933 provides good moisture protection, there is still a need to provide a phosphor panel with even better moisture resistance.

  The use of a parylene layer as a moisture protective layer for a hygroscopic photostimulable phosphor screen layer is disclosed, for example, in EP-A 1286362 and EP-A 1286365. DE-A 19625912 and GB-A 2287864 also disclose phosphor screens containing a parylene layer.

  Screens made according to the above disclosure actually produce acceptable screens for very good overall quality, but combine good moisture resistance and good resistance to physical damage during use, especially scratch resistance There is still a need for a phosphor screen with. This problem is raised more after frequent use of the desired CsBr-based phosphor plate, with the result that its image quality is reduced as a function of time. When the plates must be cleaned or when they are removed from the cassette, the parylene layer that normally provides adequate protection against moisture for the hygroscopic CsBr-based phosphor may be damaged. This is because parylene has a very low scratch resistance, resulting in the image plate stability problem again.

  The coating of a layer on a parylene layer is highly desirable, for example as described in EP-A 1286364. From its radiation-cured polymer layer coated on the parylene layer to further essentially prevent the phosphor plate against physical damage as a scratch-resistant layer, it can be used for a long period of frequent use in an organic to parylene coating. Or it is known that the adhesiveness of an inorganic polymer layer will fall. As a result, adhesion problems can occur during the life of the image plate, especially after frequent use.

  The object of the present invention is to improve the adhesion of the organic layer on the p-xylylene (parylene) layer in order to make the sheet or foil comprising a layer unit having a parylene layer scratch resistant, and thus its moisture repellency or Moisture protection properties are maintained.

  In particular, it is an object of the present invention to provide a panel, in particular a phosphor screen or panel, which provides excellent scratch resistance in addition to protection against moisture, even after prolonged and frequent use and reuse.

  It is a further object of the present invention to provide the above-mentioned frequent use of storage phosphor panels, even in the case of storage phosphor panels having a phosphor layer coated with highly moisture sensitive and photostimulable doped alkali halide phosphors. It is intended to prevent loss of image quality after extensive reuse, in particular to provide a storage phosphor panel without a binder therefor which has excellent scratch resistance.

  A further object of the present invention is a method for improving the adhesion of an organic coating onto a p-xylylene (parylene) polymer layer and a method for producing a plate or panel having a phosphor layer coated with such a protective outermost layer unit. Is to provide.

  The object mentioned above is by providing a sheet or foil comprising a layer unit of organic coating on a p-xylylene (parylene) polymer layer having the special characteristics defined in independent claim 1 and said p-xylylene ( This is achieved by applying a method for improving the adhesion of the organic coating on the (parylene) polymer layer. Specific features for preferred embodiments of the invention are disclosed in the dependent claims with respect to said sheets or foil-coated panels, in particular phosphor panels, and methods for producing such sheets, foils or panels.

  Further advantages and specific examples of the present invention will become apparent from the description below.

式中、Ｒ^１，Ｒ^２及びＲ^３の各々は同じか又は異なり、水素、飽和又は不飽和、置換又は非置換脂肪族基及び置換又は非置換芳香族基からなる群から選択される。
全ての三つのＲ置換基に対する水素の同時存在は除外されることは明らかである。なぜならばその場合において一般式（Ｉ）はもはや有機燐酸エステルではなく、燐酸自体を表すからである。さらに有機又は無機（通常アルカリ金属）塩も述べられる。 The sheet or foil according to the invention comprises a layer unit divided into at least two layers, namely layer A which is a parylene layer and optionally layer B which is present on both sides of layer A (in this case B-A- A three-layer unit of B with an A layer between two B layers), characterized in that it comprises at least one phosphate compound according to the following general formula (I):

Wherein each of R ¹ , R ² and R ³ is the same or different and is selected from the group consisting of hydrogen, saturated or unsaturated, substituted or unsubstituted aliphatic groups and substituted or unsubstituted aromatic groups.
Obviously, the simultaneous presence of hydrogen for all three R substituents is excluded. This is because in that case the general formula (I) is no longer an organic phosphoric ester, but phosphoric acid itself. Furthermore, organic or inorganic (usually alkali metal) salts are also mentioned.

  Sheets or foils in the layer arrangement AB are very useful for forming a package for each moisture sensitive object, wherein preferably the foil is in contact with the A layer in contact with the object and the surrounding atmosphere. It has a B layer, which should be protected from scratches and moisture that can irreversibly damage the parylene moisture barrier. Alternatively, the sheets or foils in the layer arrangement B-A-B may be recommended as extra protection against scratches that are damaged not only from the ambient atmosphere but also from, for example, the sharp edges of the object to be packaged.

  According to the invention, the sheet or foil with layer B is methacrylic ethyl phosphate, acrylic ethyl phosphate, dimethacrylic ethyl phosphate, methacrylic ethyl methacrylpropyl phosphate, diacrylic ethyl phosphate, methacrylpropyl phosphate, acrylpropyl phosphate, dimethacrylpropyl phosphate, Methacrylethyl methacrylpropyl phosphate, dodecyl polyethylene glycol phosphate, polyethylene glycol tridecyl ether phosphate, monoalkylphenyl polyethylene glycol phosphate, dioctylphenyl polyethylene glycol phosphate, 2- (phosphonoxy) ethyl-2-propenoate, 4- (phosphonoxy) butyl-2 -Propenoate and phosphine Nicobis (oxy-2,1-ethanediyl) -di-2-propenoate, tris-acryloyl-oxyethyl phosphate, nonylphenol ethoxylate phosphate, phenol ethoxylate phosphate, diethyl (ethoxycarbonyl-methane) phosphonate, ethoxylated fatty alcohol phosphate, Ethoxylated tridecyl phosphate mixture, mono, di, tri-tridecyl ethylene glycol phosphate mixture, polyethylene glycol tridecyl ether phosphate, diethyl ethyl phosphonate, dimethyl propyl phosphonate, diethyl N, N-bis (2-hydroxyethyl) aminomethyl Phosphonate, methyl phosphonate (5-methyl-2-methyl-1,3,2-dioxaphosphorinan-5-yl) Steal, P, P′-dioxide, phosphonic acid, methyl (5-methyl-2-methyl-1,3,2-dioxaphosphorinan-5-yl) methyl, methyl ester, P-oxide, triethyl phosphate, 2 A group of compounds consisting of ethylhexyl diphenyl phosphate, iso-decyl diphenyl phosphate, isopropylated triphenyl phosphate, isopropylated triphenyl phosphate, isobutylated triphenyl phosphate, triphenyl phosphate, cresyl diphenyl phosphate, tributyl phosphate and tricresyl phosphate At least one phosphate compound selected from (but not limited to).

  Typical examples of aliphatic ester compounds suitable for use as the phosphate ester in layer B above are methacrylic ethyl phosphate, acrylic ethyl phosphate, dimethacrylic ethyl phosphate, diacrylic ethyl phosphate, methacrylic ethyl methacrylpropyl phosphate, dodecyl polyethylene glycol phosphate. And polyethylene glycol tridecyl ether phosphate.

  Typical examples of aromatic ester compounds suitable for use as the phosphate ester in layer B above are monoalkyl phenyl polyethylene glycol phosphate (RHODIA CHEMIE, known as “RHODAFAC RE870” from France) and dioctyl phenyl polyethylene glycol phosphate ( "RHODAFAC RM710" from RHODIA); nonylphenol ethoxylate phosphate ester (CAS No. 68415-253) and phenol ethoxylate phosphate ester (CAS No. 39464-70-5).

  Typical examples of saturated ester compounds suitable for use as the phosphate ester in layer B above are 2- (phosphonoxy) ethyl-2-propenoate (CAS No. 32120-16-4), 4- (phosphonoxy) butyl-2 -Propenoate (CAS No. 110507-31-8), phosphinicobis (oxy-2,1-ethanediyl) -di-2-propenoate (CAS No. 40074-34-8) and tris-acryloyl-oxyethyl phosphate (CAS No. 35057-49-9).

  Other well known phosphate esters suitable for use in the layer arrangement of the present invention described above are commercial products from RHODIA such as PHOSBRITE® 156, 171, 193, 261, 265, 271, 272 and 951. RHODAFAC® RA500 (CAS No. 68130-47-2) and RHODAFAC® ASI80; diethyl (ethoxycarbonylmethane) phosphonate; ethoxylated fatty alcohol phosphate LUBROPOS® RD / 510-E; ethoxyl Tridecyl phosphate mixture RHODAFAC® RS-610E; mixture of mono, di, tri-tridecyl ethylene glycol phosphate; polyethylene glycol tridecyl ether phosphate R ODAFAC® RS410, diethyl ethyl phosphonate (CAS No. 765-79-6), dimethylpropyl phosphonate (CAS No. 18755-43-6), diethyl N, N-bis (2-hydroxyethyl) aminomethyl phosphonate (CAS No. 2781-11-5), phosphonic acid methyl (5-methyl-2-methyl-1,3,2-dioxaphosphorinan-5-yl) ester, P, P'-dioxide (CAS No. 42595-45-9), phosphonic acid, methyl (5-methyl-2-methyl-1,3,2-dioxaphosphorinan-5-yl) methyl, methyl ester, P-oxide (CAS No. 41203-81). -0), and triethyl phosphate (CAS No. 78-40-4).

  Suitable alkylaryl phosphates for use in the layer arrangement of the present invention described above are, for example, 2-ethylhexyl diphenyl phosphate (known as PHOSFLEX® 362) and isodecyl diphenyl phosphate PHOSFLEX® 390, PHOSFLEX Products with the trademark are manufactured by Akzo NV, Arnhem, The Netherlands.

  Suitable triaryl phosphates for use in the layer arrangement of the present invention described above include, for example, isopropylated triphenyl phosphate PHOSFLEX® 31L, isopropylated triphenyl phosphate PHOSFLEX® 41L, isobutylated triphenyl phosphate PHOSFLEX ( Registered trademark 71B, triphenyl phosphate PHOSFLEX® TPP, cresyl diphenyl phosphate PHOSFLEX® CDP and tricresyl phosphate (CAS No. 1330-78-5), but as PHOSFLEX® Known tributyl phosphate is a preferred example of an alkyl phosphate. Further particularly useful products are PHOSFLEX (R) A314, PHOSFLEX (R) A318, PHOSFLEX (R) A319, PHOSFLEX (R) A321 and PHOSFLEX (R) A327.

  In accordance with the present invention, a panel having a sheet or foil is provided, wherein a layer unit as disclosed above is present on at least one side of the support as a protective layer arrangement. The support can be any known support: foil, fiber (eg carbon fiber reinforced resin sheet, in particular each of which is arranged in a direction in which the directions of the carbon fibers of the carbon fiber reinforced resin sheet are different from each other). And those containing carbon fibers impregnated with a heat resistant resin) and particles. Chemically reinforced glass or crystalline glass can be used as the inorganic non-metallic support. Suitable inorganic metal supports for use are metal supports such as aluminum, titanium, lead, iron, copper, steel, molybdenum, beryllium supports; aluminum oxide, titanium oxide, lead oxide, copper oxide, beryllium oxide Metal and non-metal oxide supports such as manganese oxide, tungsten oxide, vanadium oxide, and silicon oxide supports.

  The organic support may include, but is not limited to, polyimide sheets, epoxy compounds and various compositions, polyethers, polyesters and polycarbonate compositions of thermoplastic and thermosetting compounds. It is recommended that the support be subjected to a cleaning procedure for cleaning and degreasing before applying the protective layer unit or arrangement as described above.

  Panels having sheets or foils according to the invention, thus protected from moisture and scratches, can be obtained from the aforementioned support material and parylene layer (if disclosed in EP-A 0226193 and the corresponding US-A 4784881). It may be advantageous to have a phosphate primer as an adhesive between the support and the phosphor layer (if present). It has been shown therein that a phosphate ester primer that promotes adhesion can act as a “bridge” between the support surface and the p-xylene polymer. For example, the divalent p-xylylene radical condenses almost immediately on the support, as in the coating procedure described in Kirk-Othmer's Encyclopedia in Chemical Technology, Third Edition, Vol 24, pages 746-747 (1984). And polymerize, thereby forming a dense and uniform coating film. The solvent may vary as a function of the phosphate compound that promotes the adhesion utilized. Suitable solvents include, but are not limited to, alcohols, ketones, toluene, alkyl acetates of any volume ratio. In such a solution, the amount of the phosphoric ester compound may vary from 0.05 to 50% by weight depending on the solvent used. A preferable concentration is, for example, a concentration of 0.1 to 20% by weight. The support may be treated with such a solution according to conventional techniques such as direct impregnation or immersion of the support in solution or spraying. The solvent is further removed from the support by evaporation at room temperature or higher depending on the nature of the solvent used in most cases.

  However, according to the present invention, when the phosphor layer of a panel, sheet, plate or screen is coated with such a layer unit, and said layer unit acts as a barrier between the phosphor layer and the ambient air, in addition to moisture protection It was totally unexpected to obtain improved adhesion and reduced scratch sensitivity. The phosphor layer of the sheet, plate or screen is present on the support and in most cases is coated on the support so it is a supported layer, sheet, plate or screen, but instead it is It may be made as a self-supporting unit before it is brought into contact with the support and then laminated or glued onto it.

  According to the invention, the phosphor layer, sheet, plate or screen has a major surface and an edge, and the parylene layer A closest to the phosphor layer is the group in which the parylene consists of parylene C, parylene D and parylene HT. A panel is provided that is a layer selected from:

  The phosphor layer, sheet, screen or panel is thus supported and is usually on one side of the support. However, there is a protective layer unit as disclosed above on the same side of the support, where layer A closer to the phosphor layer, sheet, screen or panel is present as an internal layer of that unit, while The layer B exists as the outermost layer farther from the support than the layer A. Since the phosphor panel usually has a support that is impermeable to moisture, it is not required to have a parylene layer on the opposite side where no phosphor is present. However, for use in certain applications where the same or different (e.g., different layer thickness and / or phosphor composition) phosphor layers are present, the method uses the same protective layer unit on the opposite side of the support. It is recommended to protect the phosphor layer. The double-coated phosphor layer arrangement is sandwiched between two layer units that protect both phosphor layers against moisture and scratches in that special case. In that case, in a preferred example, the protective layer expands the dimensions of the parylene, where the parylene layer is melted at the edges to avoid moisture ingress along the edges. Furthermore, it is highly recommended for protection against scratches to be coated at the edge with layer B having a phosphate ester compound as described above, for example by spray coating or dip coating.

  According to the invention, the panel further comprises a support having a surface that is larger than the major surface of the phosphor layer, so that the phosphor layer releases a portion of the support and the layer A is defined by the phosphor layer. Covering at least a portion of the portion of the released support. Layer B in contact with layer A optionally covers that open portion of the support.

  According to the present invention for a panel as described above, in a preferred example, layer A has a thickness in the range of 0.05 μm to 20 μm, more preferably 1 μm to 10 μm.

  Further, according to the present invention for the panel as described above, the layer B existing as the outermost layer in the preferred example has a thickness t, and the thickness t in the Taber abrasion test (sandpaper P220, load 250 g, 500 cycles). Lose up to 10% of

  In the panel according to the invention, the layer B is preferably a radiation-cured or thermoset polymer layer. No general concentration of phosphate compound in the coating solution of layer B is given. This is because it is highly dependent on the reactivity of the ester: highly reactive esters such as acrylate esters may be present in an amount above the average concentration.

  The above-mentioned advantageous effects are realized by adding a phosphate ester compound to the lacquer of the outermost scratch-resistant layer, one side in contact with the moisture protective pareline layer and the other side in contact with ambient air. The adhesion of the outermost protective layer to the moisture protective parylene layer between the outermost layer and the phosphor layer is thereby considerably improved, and the presence of the phosphate ester compound actually improves the scratch resistance of the topcoat layer. It improves considerably.

  According to the present invention, a panel that is a photostimulable phosphor layer, also referred to as a “storage phosphor layer” (as opposed to a conventionally known prompt phosphor layer in a scintillator or intensifying screen in a scintillator panel) is preferred. However, the present invention is also applied to prompt phosphor layers. This is because alkali halide prompt phosphors and scintillators are also very moisture sensitive. Storage phosphor panels that have a protective parylene layer as the outermost layer that protects against moisture, in fact, gradually loses resistance to moisture during use: it is also very easy when the layer is used in automatic panel handling equipment It appears to be physically damaged or easily worn, and therefore loses moisture resistance as a result of insufficient scratch resistance during use. It has been found that by applying a protective layer on top of the parylene layer as in the layer arrangement of the present invention, the physical wear of the panel is sufficiently prevented and therefore the service life of the panel is extended. Provided that at least one phosphate compound is present in the coating solution for that layer as previously disclosed. The following provides further details regarding the special layers used in the special storage phosphor panels of the present invention.

Layer A in the phosphor panel of the invention
Preferred polymers for use in the manufacture of layer A of the phosphor panel of the present invention are poly (p-xylylene), poly (p-2-chloroxylylene), poly (p-2,6-dichloroxylylene) and Fluoro-substituted poly (p-xylylene).

  The most preferred polymer for use in the protective layer of the present invention is a vacuum-deposited, preferably chemical vacuum-deposited poly-p-xylylene film. Poly-p-xylylene has repeating units in the range of 10 to 10,000, each repeating unit having a substituted or unsubstituted aromatic nucleus group. Each substituent (if present) can be the same or different and can be any inert organic or inorganic group that can normally be substituted for the aromatic nucleus. Examples of such substituents are alkyl, aryl, alkenyl, amino, cyano, carboxyl, alkoxy, hydroxylalkyl, carbalkoxy and similar groups and inorganic ions such as hydroxyl, nitro, halogen and other similar groups (they are aromatic nuclei). And can usually be substituted). Particularly preferred substituents are simple hydrocarbon groups such as lower alkyl groups such as methyl, ethyl, propyl, butyl, hexyl groups and especially halogen groups such as chlorine, bromine, iodine and fluorine, and cyano groups and hydrogen.

UNION CARBIDE Co. under the trademark “PARYLENE” as a basic drug. Commercially available di-p-xylylene compositions sold by Preferred compositions for the moisture resistant protective layer covering the phosphor layer screen or sheet are unsubstituted "PARYLENE N", monochloro substituted "PARYLENE C", dichloro substituted "PARYLENE D" and "PARYLENE HT". "(Fully fluorine-substituted type PARYLENE N. Contrary to other" Parylene ", it has heat resistance up to 400 ° C and UV resistance, and moisture resistance is the same as" PARYLENE C ". Brings things: “High Performance Coating for Electronics Resisting Hydrocarbons and High Temperature” by Guy Hall, Specialty Coating Systems, Indianapoli , Possible) see description of) obtained by Www.Scscookson.Com. Technical reports are available by the Specialty Coating Systems, Cookson Company, for example on “Solvent Resistance of the parallels” where the effects of a wide variety of organic solvents on Parylene N, C and D are being investigated. The most preferred polymers for use in the preparation of layer A of the phosphor panel of the present invention are poly (p-2-chloroxylylene), i.e. PARYLENE C film, poly (p-2,6-dichloroxylylene), i.e. PARYLENE D film and “PARYLENE HT” (PARYLENE N of a fully fluorinated type). Parylene is available from a variety of sources and is commonly used to protect printed circuit boards, sensors, and other electrical and electronic devices. Although the particular method in which parylene is applied to the phosphor layer does not form any part of the present invention, it is preferred to apply the parylene layer by chemical vapor deposition (CVD). Methods for doing so are disclosed in EP-A 1286362, EP-A 1286363, EP-A 1286364 and EP-A 1286365. The deposition method is basically as follows:

Suitable dimers-for example for the deposition of PARYLENE N (cyclo-di (p-xylene), cyclo-di (p-2-chloroxylene) for the deposition of PARYLENE C) or cyclo-di for the deposition of PARYLENE D (P-2,6-dichloroxylene)-is heated and decomposed into two radicals, which are deposited on the phosphor layer where they polymerize to form a polymer layer. Chemical vapor deposition of PARYLENE N, C or D) has several advantages:
The layer is deposited without pinholes. The barrier layer is not only deposited on the main surface of the phosphor layer, but also on the edges, thus completing the sealing of the phosphor layer.
Preferably layer A is in intimate contact with the phosphor layer in the phosphor panel of the present invention.

Layer B in the phosphor screen of the present invention
Layer B in the phosphor screen of the present invention can be any known polymer layer that applies a protective layer to the phosphor screen. However, the condition is that the layer B contains at least one phosphate ester compound. In a preferred example according to the invention, the phosphate compound is selected from the group of compounds disclosed previously. Layer B is coated on the phosphor panel by directly applying a coating solution containing a film-forming organic solvent soluble polymer such as nitrocellulose, ethyl cellulose or cellulose acetate or poly (meth) acrylic resin and removing the solvent by evaporation. Can be done. According to another technique, a clear, thin, tough, flexible, dimensionally stable polyamide film is bonded to a phosphor panel as described in published EP-A 392474.

  In a preferred example, layer B is made of a radiation curable composition. Thus, according to the present invention, a radiation curable polymer layer is provided. The use of radiation curable coatings as protective top layers in X-ray conversion screens is described, for example, in EP-A 209358 and JP-A 86176900 and US-A 48933021. For example, the protective layer comprises a UV curable resin composition formed by monomers and / or prepolymers polymerized by free radical polymerization with the aid of a photoinitiator. The monomer compound is preferably a solvent for the prepolymer used.

  Radiation curable compositions that are very useful for forming protective coatings according to the invention are as main components: (1) crosslinkable prepolymers or oligomers or mixtures of crosslinkable prepolymers or oligomers, (2) reactive diluent monomers or Contains a mixture of reactive diluent monomers, and (3) a photoinitiator in the case of UV curable formulations. Calculated for the total coating composition, the usual amounts of these main components are 30-100% by weight for the prepolymer, 10-70% by weight for the reactive diluent and 0-10% by weight for the photoinitiator. A non-reactive organic solvent may be present for the prepolymer, which is required as in the case of spray coating or dip coating.

  Any known radiation curable composition can be used, for example the composition disclosed in EP-A 510735, but the coating solution contains a fluorinated compound so that the finished protective layer contains a fluorinated moiety. It is extremely beneficial to have

  As desired, layer B of the phosphor panel of the present invention is the outermost layer in contact with ambient air with good wear. Layer B wearability was tested in a Taber abrasion test using a rotating element CALIBRASE CS10F, sandpaper P220, and a TELEDYNE TABER 5130 abrasion tester (Taber Industries, New York, US trademark) with a load of 250 g on each element. The According to the present invention, the percentage thickness loss of layer B can be measured after 500 cycles. Preferably layer B loses up to 10% of its thickness in the test described above. If desired or necessary, layer B of the present invention may contain spacing particles to further improve mobility and adjust electrostatic properties. Suitable spacing agents in the form of friction reducing polymer beads are selected from the group consisting of solid polystyrene, solid polyalkylenes and solid organic fluorinated polymers. Preferably the spacing agent is a bead comprising a fluorinated moiety. Such beads are described in US-A 4,059,768. There is a trend towards increasingly compact devices in the construction of scanning devices used to read storage phosphor screens, and thus the distance between the (moving) storage phosphor screen and the mechanical (moving) portion of the scanning device Can be very small (eg, 10-100 μm).

And when the storage phosphor screen with layer B according to the invention has protruding beads, even if the beads do not touch the mechanical part of the scanning device and the storage panel shows some stagger during movement in the scanning device. It is important that this is true. Therefore, the beads used as spacing particles in the storage phosphor screen of the present invention have a volume average diameter _dv50 such that 5 μm ≦ d _v50 ≦ 25 μm and 1 ≦ d _v50 / dn ₅₀ ≦ 1.20. It preferably has a number average diameter _dn50 . More beads are preferably adapted to the thickness t of the layer B on the storage panel of the present invention, therefore the polymer beads have a 1.25 ≦ _d v50 /t≦4.0 volume average diameter _{d v50.}

Storage phosphor layer in the phosphor panel of the present invention The storage phosphor layer in the panel of the present invention may comprise any known photostimulable phosphor. The phosphor layer in the panel according to the invention may be a layer containing a phosphor mixed with a polymer binder as well as a phosphor layer without a binder. A phosphor panel having a protective layer according to the present invention may comprise a hygroscopic phosphor. The panel according to the invention preferably has a photostimulable phosphor layer, which layer comprises a photostimulable phosphor without binder. A preferred panel according to the invention is a CsX: Eu stimulable phosphor as described in WO 01/03156 (X is a halide selected from the group consisting of Br and Cl). Panel). In addition to CsX as the matrix compound and Eu as the dopant, further impurity elements may be present in the phosphor composition, whether or not as impurities. The binderless CsX: Eu stimulable phosphor layer comprises acicular phosphor particles separated by a gap. The gap may be filled to the specified range as described in EP-A 1316969 and 1347460. For image sharpness, the phosphor particles may be colored with nanocrystalline dyes as described in EP-A 1349177.

  When layer A having very low water permeability is deposited on such a phosphor layer having needle-like phosphor crystals separated by a gap, this layer A is a chemical vacuum deposited parylene layer, while such a layer is a needle In addition to covering the surface of the needle-like crystals, it is preferable to enter the gap between the needle-like crystals to cover the edges and to completely protect the edges of the phosphor needle-like crystals against moisture. The phosphor panels of the present invention may include edge reinforcement such as those described in US-A 5,334,842 and US-A 5,340,661.

  The phosphor panel of the present invention can be a self-supporting panel as well as a panel comprising a support. The support can be any known support, but a support having a very low water vapor permeability is preferably used because of the desired high moisture resistance of the screen. Preferred supports are anodized aluminum supports and supports as disclosed in EP-A 1316971 and EP-A 1316972.

  In a particular example of the invention, the surface of the phosphor layer is smaller than the surface of the support, so that the phosphor layer does not reach the edge of the support. Of the support having a surface having a surface larger than the main surface of the phosphor layer, so that the phosphor layer opens a portion of the support and the protective layer comprising layers A and B is opened by the phosphor layer. A panel that at least partially covers a portion represents a particular example of the present invention as previously disclosed. The advantage of such a configuration lies in the fact that the edges of the phosphor layer do not touch the mechanical parts of the device during use of the panel, for example during movement in the scanning device, and are less easily damaged. Another advantage of this configuration is that no special edge reinforcement is required. However, additional edge reinforcement can be applied if desired. A phosphor panel configuration where the surface of the phosphor layer is smaller than the surface of the support, and therefore the phosphor layer does not reach the edge of the support, represents a particular example of the present invention; It may be beneficial to produce any covered phosphor panel.

  When a parylene layer is present between the support material and the phosphor layer, the surface roughness of the covered support is reduced (preferably 0.5 or less, more preferably 1.0 or less). ) Which shows good smoothness, which can be advantageous for depositing columnar crystals or needle-like crystals with small diameters, whereby the surface area of the deposited photostimulable phosphor layer per unit square This leads to improved packing density and improved sharpness or resolution of the needle-like crystals. Further details on the dimensions of such columnar, acicular or cylindrical phosphors are disclosed in EP-A 1359204.

  The present invention further includes a method for improving the adhesion of an organic coating on a p-xylylene (parylene) polymer layer by adding at least one phosphate ester compound to the organic coating solution, the at least one phosphate ester The compound is represented by the following general formula (I), in which methacrylethyl phosphate, acrylethyl phosphate, dimethacrylethyl phosphate, methacrylethyl methacrylpropyl phosphate, diacrylethyl phosphate, methacrylpropyl phosphate, acrylpropyl phosphate, dimethacrylpropyl phosphate , Methacrylethyl methacrylate propyl phosphate, dodecyl polyethylene glycol phosphate, polyethylene glycol tridecyl ether phosphate, monoa Quilphenyl polyethylene glycol phosphate, dioctyl phenyl polyethylene glycol phosphate, 2- (phosphonoxy) ethyl-2-propenoate, 4- (phosphonoxy) butyl-2-propenoate, and phosphinicobis (oxy-2,1-ethanediyl) -di-2- Propenoate, tris-acryloyl-oxyethyl phosphate, nonylphenol ethoxylate phosphate, phenol ethoxylate phosphate, diethyl (ethoxycarbonyl-methane) phosphonate, ethoxylated fatty alcohol phosphate, ethoxylated tridecyl phosphate mixture, mono, di, tri-tridecyl A mixture of ethylene glycol phosphate, polyethylene glycol tridecyl ether phosphate, die Ruethylphosphonate, dimethylpropylphosphonate, diethyl N, N-bis (2-hydroxyethyl) aminomethylphosphonate, methyl phosphonate (5-methyl-2-methyl-1,3,2-dioxaphosphorinan-5-yl ) Ester, P, P′-dioxide, phosphonic acid, methyl (5-methyl-2-methyl-1,3,2-dioxaphosphorinan-5-yl) methyl, methyl ester, P-oxide, triethyl phosphate, 2-ethylhexyl diphenyl phosphate, iso-decyl diphenyl phosphate, isopropylated triphenyl phosphate, isopropylated triphenyl phosphate, isobutylated triphenyl phosphate, triphenyl phosphate, cresyl diphenyl phosphate, tributyl phosphate And tricresyl phosphate, which is specified as being selected from the group of compounds consisting of (but not limited to).

The present invention further includes a method of making a binderless phosphor panel comprising the following steps:
-Providing a support, optionally coated with a parylene layer;
CsX: Eu phosphor, where X represents a halide selected from the group consisting of Br and Cl, and thereby a binderless phosphor on said (optionally coated) support Forming a layer;
Applying a layer of parylene onto the binder-free phosphor layer by chemical vapor deposition, thereby forming layer A;
Applying a radiation curable solution comprising at least one phosphate compound on said layer A;
Curing the panel by UV and / or electron beam exposure, thereby forming layer B;

  As an advantageous effect of the present invention, it has been demonstrated that the physical stability of the phosphor imaging plate meets the most stringent conditions in that the image quality does not change with long term frequent use.

  The improved adhesion due to the use of phosphate compounds in organic coatings applied on the parylene layer clearly leads to reliable radiographic imaging plates over a very long period even after frequent reuse.

EXAMPLES While the present invention will be described below in connection with preferred examples thereof, it will be understood that it is not intended to limit the invention to those examples.

In the first experiment , a CsBr: Eu screen was made by thermal evaporation of CsBr and EuOBr. CsBr was therefore mixed with EuOBr and placed in a container within the deposition chamber. The phosphor was deposited on a glass disk having a thickness of 1.5 mm and a diameter of 40 mm. The distance between the container and the support was 10 cm. During evaporation, the support is 12r. p. m. It was rotated by.

The vessel with the starting material was heated to a temperature of 750 ° C. The chamber was evacuated to a pressure of 4 × 10 ⁻⁵ mbar before the start of evaporation. During the evaporation process, Ar was introduced into the chamber, the support temperature was 150 ° C., and the Ar pressure was 2.2 Pa. The Eu concentration in the evaporated screen is measured by X-ray fluorescence and is 800 p. p. m. It was an order.

The screen was divided into four parts to make four test screens :
1. No protective layer was applied on the first part.
2. A radiation curable solution was applied by screen printing on the second part, followed by UV curing to produce a protective layer ( layer B 1 of the present invention) having a thickness of 10 μm. Examples of the composition of these radiation curable solutions for producing layer B of the present invention are described below.
3. A layer of Parylene C was deposited on the third part by chemical vapor deposition according to the known Gorham method to give an 8 μm thick layer ( layer A of the present invention).
4). A layer of Parylene C as on the third part was applied on the fourth part, and a radiation cured layer as on the second part was applied thereon. In this screen both layers A and B of the invention are thus present.

  Screen quality was tested by immersing four test screens in water for 24 hours, checking the physical integrity of the screens, and if possible checking the speed performance. Furthermore, the surface strength was tested on a rotating element CALIBRASE CS10F, sandpaper P220, TELEDYNE TABER 5130 abrasion tester with a load of 250 g on each element.

The percentage of layer thickness loss was measured after 500 cycles. The results are summarized in Table 1 below.

In a second experiment , several coating solutions were applied on the Parylene C layer deposited on the aluminum support by various application techniques to study adhesion improvements when using phosphate esters.

Application A: 5.0 g of (MMA-co-BMA) -copolymer was dissolved in 25.0 g of 1,6-hexanediol diacrylate. To this solution, 25.0 g BASF Laromer TMPTA and 45.0 g Ebecryl 1290, UCB hexafunctional urethane acrylate were added and homogenized. To this, 3.0% Modaflow from MONSANTO was added to increase the dispersion on the parylene layer. 4.0 g Darocur 1173 from CIBA (Germany) and 4.0 g benzophenone were dissolved in the lacquer as initiator for UV curing. The coating solution was applied by screen printing and polymerized by UV curing with an intensity of 200 mW / cm ² .

  Application B: To 20.0 g of the solution used in Application A, 5.0 g of RHODIAC Rhodafac RM710, dioctylphenyl polyethylene glycol phosphate was added as a “Parylene Adhesion Improving” agent. The coating solution was applied and cured as in Application A.

  Application C: 0.1 g to 20.0 g of the oligomer coating solution of Application A containing (MMA-co-BMA) -copolymer, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate and hexafunctional urethane acrylate A 3% fluorosurfactant from 3M was added to increase dispersibility and layer uniformity, and 0.8 g Darocur 1173 and 0.8 g benzophenone were added to allow radical polymerization by UV exposure. As the phosphate ester, 2.0 g of dipolyoxyethylene tridecyl ether phosphate was dissolved in the coating solution. A clear, low-viscosity 5% oligomer coating solution with the addition of a solvent mixture of 40% methyl ethyl ketone, 30% methyl isobutyl ketone and 30% methoxy propanol to reduce its viscosity and enable spraying Became. This solution was sprayed onto the parylene layer, after which the coating was formed by evaporating the solvent at high temperature and UV curing.

  Application D: 10 g Neocryl B-725 from ZENECA, 60 g 50% trimethylolpropane triacrylate / 40% poly (oxy-1,2-ethanediyl-hydro- (1-oxo-2-propenyloxy)) Dissolve in a mixture of ether / 10% 2-ethyl-2 (hydroxymethyl) -1,3-propanediol, then 30.0 g hexafunctional urethane acrylate and 20.0 g siloxazan with 500 g methyl ethyl ketone and 380 g diethyl A clear, low-viscosity solution (5 mPa.s viscosity) was obtained with the addition of ketone. To increase adhesion to the parylene layer after application by dip coating and UV curing, Rhodafac RS410 from 5.0 g RHODIA and 15.0 g phosphinicobis (oxy-2,1-ethanediyl) -di-2-propenoate, Acrylic phosphate diester was added to the coating solution. The UV initiator was 4.0% 1-hydroxy-cyclohexyl-phenyl ketone and 2.0% benzophenone.

  Application E: A solution of polysiloxazan and urethane acrylate is sprayed onto the parylene layer, cured for 20 hours under the influence of atmospheric moisture at 60 ° C., 6 μm wear resistance, clear, not brittle, good adhesion A layer having properties was obtained. The polymer solution applied was 7.5 g poly (oxy-1,2-ethanediyl-hydro- (1-oxo-2-propenyloxy))-ether, 2.5 g 2-ethyl-2 (hydroxymethyl) -1,3-propanediol, 5.0 g Sartomer SR238, 15.0 g Ebecryl 1290 and 60.0 g KION Corp. , Columbus, USA Kion ML33 / C33 mixture. These oligomers were dissolved in a mixture of 400 g methyl ethyl ketone, 150 g methyl isobutyl ketone and 150 g methoxypropanol. In order to obtain a good thermosetting layer, tertiary butyl peroxy-2-ethylhexyl carbonate was added to the solution in a proportion of 5% by weight. As an adhesion promoter, mono (alkylphenyl polyethylene glycol) -phosphate was added in a proportion of 5% by weight. Layer leveling was improved by adding 0.25 wt% BYK UV3500 from BYK Chemie.

  The adhesion of the applied protective layer on the parylene layer was evaluated by a cross-cut adhesion test according to standard ASTM D3359-D3002 / DIN53151 / ISO 2409 using a cutter supplied by BRAIVE INSTRUMENTS, Belgium. The test was performed with corresponding tape from the same supplier.

  The abrasion resistance of the protective layer was tested with a Calibele CS10F element and a Teledyne Taber 5130 abrasion tester with a 250 g load on each element.

  Layer mass loss (in milligrams) was measured after 100 cycles. The wear area was constant for all tests.

The results are summarized in Table 2 below.

  It is clear that the adhesion is strongly increased by utilizing phosphate esters in the outermost coating solution on the moisture-protected parylene layer. No adverse effect on the abrasion resistance of the protective layer was observed, so the object of the present invention was fully achieved.

  While preferred examples of the present invention have been described in detail, it will be apparent to those skilled in the art that numerous changes can be made therein without departing from the scope of the invention as defined in the appended claims.

Claims (9)

In a sheet or foil comprising a layer unit divided into at least two layers, namely layer A which is a layer of p-xylylene (parylene) and optionally layer B present on both sides of layer A, the following general formula (I A sheet or foil comprising at least one phosphate ester compound according to

Wherein each of R ¹ , R ² and R ³ is the same or different and is selected from the group consisting of hydrogen, saturated or unsaturated, substituted or unsubstituted aliphatic groups and substituted or unsubstituted aromatic groups.   The phosphoric acid ester compound is methacrylic ethyl phosphate, acrylic ethyl phosphate, dimethacrylic ethyl phosphate, methacrylic ethyl methacryl propyl phosphate, diacrylic ethyl phosphate, methacryl propyl phosphate, acryl propyl phosphate, dimethacryl propyl phosphate, methacryl ethyl methacryl propyl phosphate, dodecyl polyethylene Glycol phosphate, polyethylene glycol tridecyl ether phosphate, monoalkylphenyl polyethylene glycol phosphate, dioctylphenyl polyethylene glycol phosphate, 2- (phosphonoxy) ethyl-2-propenoate, 4- (phosphonoxy) butyl-2-propenoate, and phosphinico bis (ox -2,1-ethanediyl) -di-2-propenoate, tris-acryloyl-oxyethyl phosphate, nonylphenol ethoxylate phosphate, phenol ethoxylate phosphate, diethyl (ethoxycarbonyl-methane) phosphonate, ethoxylated fatty alcohol phosphate, ethoxylated tri Decyl phosphate mixture, mono, di, tri-tridecyl ethylene glycol phosphate mixture, polyethylene glycol tridecyl ether phosphate, diethyl ethyl phosphonate, dimethyl propyl phosphonate, diethyl N, N-bis (2-hydroxyethyl) aminomethyl phosphonate, phosphone Acid methyl (5-methyl-2-methyl-1,3,2-dioxaphosphorinan-5-yl) ester, P, P Dioxide, phosphonic acid, methyl (5-methyl-2-methyl-1,3,2-dioxaphosphorinan-5-yl) methyl, methyl ester, P-oxide, triethyl phosphate, 2-ethylhexyl diphenyl phosphate, iso Claims selected from the group consisting of decyl diphenyl phosphate, isopropylated triphenyl phosphate, isopropylated triphenyl phosphate, isobutylated triphenyl phosphate, triphenyl phosphate, cresyl diphenyl phosphate, tributyl phosphate and tricresyl phosphate The protective sheet or foil according to 1.   3. The protective sheet or foil according to claim 1 or 2, wherein the layer unit is present on at least one side of the support, and a phosphor sheet, plate or screen is present between the support and the layer unit. panel.   The panel according to claim 3, wherein the layer B is the outermost layer, has a thickness t, and loses up to 10% of the thickness t in a Taber abrasion test (sandpaper P220, load 250g, 500 cycles).   5. A panel according to claim 3 or 4, wherein the phosphor sheet comprises a photostimulable phosphor without a binder.   6. The panel of claim 5, wherein the binderless photostimulable phosphor is a CsX: Eu stimulable phosphor and X represents a halide selected from the group consisting of Br and Cl. A method for improving the adhesion of an organic coating onto a p-xylylene (parylene) polymer layer by adding at least one phosphate ester compound to an organic coating solution, wherein the at least one phosphate ester compound is Method represented by formula (I):

Wherein each of R ¹ , R ² and R ³ is the same or different and is selected from the group consisting of hydrogen, saturated or unsaturated, substituted or unsubstituted aliphatic groups and substituted or unsubstituted aromatic groups.   The phosphoric acid ester compound is the above-mentioned phosphoric acid ester compound is methacrylic ethyl phosphate, acryl ethyl phosphate, dimethacryl ethyl phosphate, methacryl ethyl methacrylate propyl phosphate, diacryl ethyl phosphate, methacryl propyl phosphate, acrylic propyl phosphate, dimethacryl propyl phosphate, methacryl ethyl methacrylate Propyl phosphate, dodecyl polyethylene glycol phosphate, polyethylene glycol tridecyl ether phosphate, monoalkylphenyl polyethylene glycol phosphate, dioctylphenyl polyethylene glycol phosphate, 2- (phosphonoxy) ethyl-2-propenoate, 4- (phosphonoxy) butyl-2-propenoate, And Phosphinicobis (oxy-2,1-ethanediyl) -di-2-propenoate, tris-acryloyl-oxyethyl phosphate, nonylphenol ethoxylate phosphate, phenol ethoxylate phosphate, diethyl (ethoxycarbonyl-methane) phosphonate, ethoxylated fatty alcohol phosphate, Ethoxylated tridecyl phosphate mixture, mono, di, tri-tridecyl ethylene glycol phosphate mixture, polyethylene glycol tridecyl ether phosphate, diethyl ethyl phosphonate, dimethyl propyl phosphonate, diethyl N, N-bis (2-hydroxyethyl) aminomethyl Phosphonate, methyl phosphonate (5-methyl-2-methyl-1,3,2-dioxaphosphorinane-5 Yl) ester, P, P'-dioxide, phosphonic acid, methyl (5-methyl-2-methyl-1,3,2-dioxaphosphorinan-5-yl) methyl, methyl ester, P-oxide, triethyl phosphate , 2-ethylhexyl diphenyl phosphate, iso-decyl diphenyl phosphate, isopropylated triphenyl phosphate, isopropylated triphenyl phosphate, isobutylated triphenyl phosphate, triphenyl phosphate, cresyl diphenyl phosphate, tributyl phosphate and tricresyl phosphate The method of claim 7, selected from the group of A method for producing a binderless phosphor panel comprising the following steps:
-Providing a support;
Depositing CsX: Eu phosphor, wherein X represents a halide selected from the group consisting of Br and Cl, thereby forming a binder-free phosphor layer on said support;
Applying a layer of parylene onto the binder-free phosphor layer by chemical vapor deposition, thereby forming layer A;
Applying a radiation curable solution comprising at least one phosphate compound on said layer A;
Curing the panel by UV and / or electron beam exposure, thereby forming layer B;