Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/28—Layered products comprising a layer of synthetic resin comprising synthetic resins not wholly covered by any one of the sub-groups B32B27/30 - B32B27/42
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K50/00—Organic light-emitting devices
  • H10K50/80—Constructional details
  • H10K50/84—Passivation; Containers; Encapsulations
  • H10K50/844—Encapsulations
  • H10K50/8445—Encapsulations multilayered coatings having a repetitive structure, e.g. having multiple organic-inorganic bilayers
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K77/00—Constructional details of devices covered by this subclass and not covered by groups H10K10/80, H10K30/80, H10K50/80 or H10K59/80
  • H10K77/10—Substrates, e.g. flexible substrates
  • H10K77/111—Flexible substrates
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K2323/00—Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K2323/00—Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition
  • C09K2323/03—Viewing layer characterised by chemical composition
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K2323/00—Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition
  • C09K2323/03—Viewing layer characterised by chemical composition
  • C09K2323/035—Ester polymer, e.g. polycarbonate, polyacrylate or polyester
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/1333—Constructional arrangements; Manufacturing methods
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K2102/00—Constructional details relating to the organic devices covered by this subclass
  • H10K2102/301—Details of OLEDs
  • H10K2102/311—Flexible OLED
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K50/00—Organic light-emitting devices
  • H10K50/80—Constructional details
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
  • H10K59/80—Constructional details
  • H10K59/87—Passivation; Containers; Encapsulations
  • H10K59/873—Encapsulations
  • H10K59/8731—Encapsulations multilayered coatings having a repetitive structure, e.g. having multiple organic-inorganic bilayers
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K77/00—Constructional details of devices covered by this subclass and not covered by groups H10K10/80, H10K30/80, H10K50/80 or H10K59/80
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E10/00—Energy generation through renewable energy sources
  • Y02E10/50—Photovoltaic [PV] energy
  • Y02E10/549—Organic PV cells
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
  • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/26—Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
  • Y10T428/263—Coating layer not in excess of 5 mils thick or equivalent
  • Y10T428/264—Up to 3 mils
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/3154—Of fluorinated addition polymer from unsaturated monomers
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/3154—Of fluorinated addition polymer from unsaturated monomers
  • Y10T428/31544—Addition polymer is perhalogenated
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31786—Of polyester [e.g., alkyd, etc.]
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31855—Of addition polymer from unsaturated monomers
  • Y10T428/31909—Next to second addition polymer from unsaturated monomers
  • Y10T428/31928—Ester, halide or nitrile of addition polymer

Definitions

• This invention relates to barrier films and electronic devices.
• OLEDs Organic light emitting devices
• Metals and glasses have been used to encapsulate and prolong the life of OLED devices, but metals typically lack transparency and glass lacks flexibility. Intensive efforts are underway to find alternative encapsulation materials for OLEDs and other electronic devices.
• a flexible polymeric barrier film that exhibited low permeability to water vapor and oxygen would be especially useful, but despite intense industrial effort only limited success has been attained thus far.
• References relating to flexible barrier films include U.S. Patent Nos.
• the present invention provides, in one aspect, a barrier assembly (sometimes referred to below as a "barrier film”) comprising a flexible visible light-transmissive substrate having a glass transition temperature (“Tg") greater than or equal to that of heat- stabilized polyethylene terephthalate (“HSPET”) overcoated with a first polymer layer having a Tg greater than or equal to that of HSPET and further overcoated with at least two visible light-transmissive inorganic barrier layers separated by at least one second polymer layer having a Tg greater than or equal to that of HSPET, the barrier assembly having an oxygen transmission rate less than 0.005 cc/m ⁇ /day at 23° C and 90% RH.
• Tg glass transition temperature
• HSPET heat- stabilized polyethylene terephthalate
• the invention provides a process for making a barrier assembly comprising: a) providing a flexible light-transmissive support having a Tg greater than or equal to that of HSPET; b) forming a first polymer layer having a Tg greater than or equal to that of HSPET atop the support; c) forming a visible light-transmissive first inorganic barrier layer atop the first polymer layer; d) forming a second polymer layer having a Tg greater than or equal to that of HSPET atop the first inorganic barrier layer; and e) forming a visible light-transmissive second inorganic barrier layer atop the second polymer layer wherein the barrier assembly has an oxygen transmission rate less than 0.005 cc/m ⁇ /day at 23° C and 90% RH.
• the invention provides a display or illuminating device comprising a moisture- or oxygen-sensitive light source or light valve at least partially covered with a barrier assembly comprising a flexible visible light-transmissive substrate having a Tg greater than or equal to that of HSPET overcoated with a first polymer layer having a Tg greater than or equal to that of HSPET and further overcoated with at least two visible light-transmissive inorganic barrier layers separated by at least one second polymer layer having a Tg greater than or equal to that of HSPET.
• Fig. 1 is a schematic cross-sectional view of a disclosed barrier assembly
• Fig. 2 is a schematic cross-sectional view of a disclosed laminated barrier assembly
• Fig. 3 is a schematic view of an apparatus for carrying out the disclosed process
• Fig. 4 is a schematic cross-sectional view of a disclosed OLED device; and [0011] Fig. 5 is a photomicrograph of a disclosed barrier assembly; [0012] Like reference symbols in the various figures of the drawing indicate like elements. The elements in the drawing are not to scale.
• polymer By using the term “polymer”, we refer to homopolymers and copolymers, as well as homopolymers or copolymers that may be formed in a miscible blend, e.g., by coextrusion or by reaction, including, e.g., transesterification.
• copolymer includes both random and block copolymers.
• cured polymer includes both crosslinked and uncrosslinked polymers.
• crosslinked polymer refers to a polymer whose polymer chains are joined together by covalent chemical bonds, usually via crosslinking molecules or groups, to form a network polymer.
• a crosslinked polymer is generally characterized by insolubility, but may be swellable in the presence of an appropriate solvent.
• Tg glass transition temperature of a cured polymer when evaluated in bulk rather than in a thin film form.
• the bulk form Tg can usually be estimated with reasonable accuracy.
• Bulk form Tg values usually are determined by evaluating the rate of heat flow vs. temperature using differential scanning calorimetry (DSC) to determine the onset of segmental mobility for the polymer and the inflection point (usually a second-order transition) at which the polymer can be said to change from a glassy to a rubbery state.
• DSC differential scanning calorimetry
• Tg values can also be estimated using a dynamic mechanical thermal analysis (DMT A) technique, which measures the change in the modulus of the polymer as a function of temperature and frequency of vibration.
• DMT A dynamic mechanical thermal analysis
• a barrier assembly is shown generally at 110.
• Support 112 is overcoated with a polymer layer 114 having a Tg greater than or equal to that of HSPET and further overcoated with two or more visible light-transmissive inorganic barrier layers such as layers 116, 120 and 124 separated by polymer layers such as layers 118 and 122.
• Assembly 110 also preferably includes a protective polymer overlayer 126 atop uppermost visible light-transmissive inorganic barrier layer 124.
• Fig. 2 shows a laminated barrier assembly 130 that can be made by laminating together two pieces of assembly 110 in face-to-face relationship using a layer of visible light-transmissive adhesive 132.
• Preferred flexible light-transmissive supports 112 have a visible light transmission of at least about 70% at 550 nm.
• PMMA polymethyl methacrylate
• the support has a thickness of about 0.01 to about 1 mm, more preferably about 0.05 to about 0.25 mm.
• a first polymer layer having a Tg greater than or equal to that of HSPET lies atop the support.
• a variety of polymer materials can be employed. Volatilizable monomers that form suitably high Tg polymers are especially preferred.
• the first polymer layer has a Tg greater than that of PMMA, more preferably a Tg of at least about 110° C, yet more preferably at least about 150° C, and most preferably at least about 200° C.
• diethylene glycol diacrylates e.g., SR-230, commercially available
• the first polymer layer can be formed by applying a layer of a monomer or oligomer to the substrate and crosslinking the layer to form the polymer in situ, e.g., by flash evaporation and vapor deposition of a radiation-crosslinkable monomer, followed by crosslinking using, for example, an electron beam apparatus, UV light source, electrical discharge apparatus or other suitable device. Coating efficiency can be improved by cooling the support.
• the monomer or oligomer can also be applied to the substrate using conventional coating methods such as roll coating (e.g., gravure roll coating) or spray coating (e.g., electrostatic spray coating), then crosslinked as set out above.
• the first polymer layer can also be formed by applying a layer containing an oligomer or polymer in solvent and drying the thus-applied layer to remove the solvent.
• Plasma polymerization may also be employed if it will provide a polymeric layer having a glassy state at an elevated temperature, with a glass transition temperature greater than or equal to that of HSPET.
• the first polymer layer is formed by flash evaporation and vapor deposition followed by crosslinking in situ, e.g., as described in U.S. Patent Nos.
• each polymer layer and its adhesion to the underlying layer preferably is enhanced by appropriate pretreatment.
• a preferred pretreatment regimen employs an electrical discharge in the presence of a suitable reactive or non-reactive atmosphere (e.g., plasma, glow discharge, corona discharge, dielectric barrier discharge or atmospheric pressure discharge); chemical pretreatment or flame pretreatment. These pretreatments help make the surface of the underlying layer more receptive to formation of the subsequently applied polymeric layer. Plasma pretreatment is particularly preferred.
• a separate adhesion promotion layer which may have a different composition than the high Tg polymer layer may also be utilized atop an underlying layer to improve interlayer adhesion.
• the adhesion promotion layer can be, for example, a separate polymeric layer or a metal-containing layer such as a layer of metal, metal oxide, metal nitride or metal oxynitride.
• the adhesion promotion layer may have a thickness of a few nm (e.g., 1 or 2 nm) to about 50 run, and can be thicker if desired.
• the desired chemical composition and thickness of the first polymer layer will depend in part on the nature and surface topography of the support. The thickness preferably is sufficient to provide a smooth, defect-free surface to which the subsequent first inorganic barrier layer can be applied.
• the first polymer layer may have a thickness of a few nm (e.g., 2 or 3 nm) to about 5 micrometers, and can be thicker if desired.
• At least two visible light-transmissive inorganic barrier layers separated by a polymer layer having a Tg greater than or equal to that of HSPET lie atop the first polymer layer. These layers can respectively be referred to as the "first inorganic barrier layer", “second inorganic barrier layer” and “second polymer layer”. Additional inorganic barrier layers and polymer layers can be present if desired, including polymer layers that do not have a Tg greater than or equal to that of HSPET.
• each neighboring pair of inorganic barrier layers is separated only by a polymer layer or layers having a Tg greater than or equal to that of HSPET, and more preferably only by a polymer layer or layers having a Tg greater than that of PMMA.
• the inorganic barrier layers do not have to be the same. A variety of inorganic barrier materials can be employed.
• Preferred inorganic barrier materials include metal oxides, metal nitrides, metal carbides, metal oxynitrides, metal oxyborides, and combinations thereof, e.g., silicon oxides such as silica, aluminum oxides such as alumina, titanium oxides such as titania, indium oxides, tin oxides, indium tin oxide ("ITO"), tantalum oxide, zirconium oxide, niobium oxide, boron carbide, tungsten carbide, silicon carbide, aluminum nitride, silicon nitride, boron nitride, aluminum oxynitride, silicon oxynitride, boron oxynitride, zirconium oxyboride, titanium oxyboride, and combinations thereof.
• silicon oxides such as silica
• aluminum oxides such as alumina
• titanium oxides such as titania, indium oxides, tin oxides, indium tin oxide ("ITO")
• Indium tin oxide, silicon oxide, aluminum oxide and combinations thereof are especially preferred inorganic barrier materials.
• ITO is an example of a special class of ceramic materials that can become electrically conducting with the proper selection of the relative proportions of each elemental constituent.
• the inorganic barrier layers preferably are formed using techniques employed in the film metallizing art such as sputtering (e.g., cathode or planar magnetron sputtering), evaporation (e.g., resistive or electron beam evaporation), chemical vapor deposition, plating and the like. Most preferably the inorganic barrier layers are formed using sputtering, e.g., reactive sputtering.
• Enhanced barrier properties have been observed when the inorganic layer is formed by a high energy deposition technique such as sputtering compared to lower energy techniques such as conventional chemical vapor deposition processes. Without being bound by theory, it is believed that the enhanced properties are due to the condensing species arriving at the substrate with greater kinetic energy, leading to a lower void fraction as a result of compaction.
• the smoothness and continuity of each inorganic barrier layer and its adhesion to the underlying layer can be enhanced by pretreatments (e.g., plasma pretreatment) such as those described above with reference to the first polymer layer.
• pretreatments e.g., plasma pretreatment
• the inorganic barrier layers do not have to have the same thickness.
• each inorganic barrier layer will depend in part on the nature and surface topography of the underlying layer and on the desired optical properties for the barrier assembly.
• the inorganic barrier layers preferably are sufficiently thick so as to be continuous, and sufficiently thin so as to ensure that the barrier assembly and articles containing the assembly will have the desired degree of visible light transmission and flexibility.
• the physical thickness (as opposed to the optical thickness) of each inorganic barrier layer is about 3 to about 150 nm, more preferably about 4 to about 75 nm.
• all or a portion of one or more of the visible light-transmissive inorganic barrier layers can be used for purposes such as an electrode (if suitably conductive) or a touch-sensitive surface.
• the second polymer layers that separate the first, second and any additional inorganic barrier layers do not have to be the same, and do not all have to have the same thickness.
• a variety of second polymer layer materials can be employed. Preferred second polymer layer materials include those mentioned above with respect to the first polymer layer.
• the second polymer layer or layers are applied by flash evaporation and vapor deposition followed by crosslinking in situ as described above with respect to the first polymer layer.
• a pretreatment such as those described above (e.g., plasma pretreatment) preferably also is employed prior to formation of a second polymer layer.
• the desired chemical composition and thickness of the second polymer layer or layers will depend in part on the nature and surface topography of the underlying layer(s).
• the second polymer layer thickness preferably is sufficient to provide a smooth, defect- free surface to which a subsequent inorganic barrier layer can be applied.
• the second polymer layer or layers may have a lower thickness than the first polymer layer.
• each second polymer layer may have a thickness of about 5 nm to about 10 micrometers, and can be thicker if desired.
• the barrier assemblies have a protective polymer topcoat.
• This topcoat can be referred to as the "third polymer layer”.
• Volatilizable (meth)acrylate monomers are preferred for use in the third polymer layer, with volatilizable acrylate monomers having a Tg greater than or equal to that of HSPET being especially preferred (e.g., those mentioned above with respect to the first and second polymer layers) and volatilizable acrylate monomers having a Tg greater than PMMA being most preferred.
• the third polymer layer can be applied using conventional coating methods such as roll coating (e.g., gravure roll coating) or spray coating (e.g., electrostatic spray coating), then crosslinked using, for example, UV radiation.
• the third polymer layer is formed by flash evaporation, vapor deposition and crosslinking of a monomer as described above with respect to the first and second polymer layers.
• a pretreatment such as those described above (e.g., plasma pretreatment) preferably also is employed prior to formation of the third polymer layer.
• the desired chemical composition and thickness of the third polymer layer will depend in part on the nature and surface topography of the underlying layer(s), the hazards to which the barrier assembly might be exposed, and applicable device requirements.
• the third polymer layer thickness preferably is sufficient to provide a smooth, defect-free surface that will protect the underlying layers from ordinary hazards.
• the third polymer layer may have a lower thickness than the first polymer layer and a greater thickness than the second polymer layer or layers.
• the third polymer layer may have a thickness of about 5 nm to about 10 micrometers, and can be thicker if desired.
• Preferred barrier assemblies have a sufficient number of inorganic barrier layers and the substrate and first and second polymer layers preferably have a sufficiently high Tg so that the barrier assembly will be visible light-transmissive and will have a water vapor transmission rate (WVTR) less than about 0.005 g/m ⁇ /day at 38° C and 100% relative humidity, more preferably less than about 0.005 g/m ⁇ /day at 50° C and 100% relative humidity and most preferably less than about 0.005 g/m ⁇ /day at 85° C and 100% relative humidity.
• Transparency values Tvis, determined by averaging the percent transmission T between 400 nm and 700 nm) of at least about 20%, more preferably at least about 60% are preferred.
• Fig. 3 shows a preferred apparatus 180 that can be used for roll-to-roll manufacture of barrier assemblies of the invention.
• Powered rolls 181a and 181b move supporting web 182 back and forth through apparatus 180.
• Temperature-controlled rotating drums 183a and 183b, and idler rolls 184a, 184b, 184c, 184d and 184e carry web 182 past metal sputtering applicator 185, plasma pretreater 186, monomer evaporator 187 and E-beam crosslinking device 188.
• Liquid monomer 189 is supplied to evaporator 187 from reservoir 190. Successive layers or pairs of layers can be applied to web 182 using multiple passes through apparatus 180.
• Apparatus 180 can be enclosed in a suitable chamber (not shown in Fig. 3) and maintained under vacuum or supplied with a suitable inert atmosphere in order to discourage oxygen, water vapor, dust and other atmospheric contaminants from interfering with the various pretreatment, monomer coating, crosslinking and sputtering steps.
• a suitable chamber not shown in Fig. 3
• Various functional layers or coatings can be added to the barrier assemblies of the invention to alter or improve their physical or chemical properties, particularly at the surface of the barrier film.
• Such layers or coatings can include, for example, visible light- transmissive conductive layers or electrodes (e.g., of indium tin oxide); antistatic coatings or films; flame retardants; UV stabilizers; abrasion resistant or hardcoat materials; optical coatings; anti-fogging materials; magnetic or magneto-optic coatings or films; photographic emulsions; prismatic films; holographic films or images; adhesives such as pressure sensitive adhesives or hot melt adhesives; primers to promote adhesion to adjacent layers; and low adhesion backsize materials for use when the barrier assembly is to be used in adhesive roll form.
• These functional components can be incorporated into one or more of the outermost layers of the barrier assembly or can be applied as a separate film or coating.
• the barrier assembly may be desirable to alter the appearance or performance of the barrier assembly, such as by laminating a dyed film layer to the barrier assembly, applying a pigmented coating to the surface of the barrier assembly, or including a dye or pigment in one or more of the materials used to make the barrier assembly.
• the dye or pigment can absorb in one or more selected regions of the spectrum, including portions of the infrared, ultraviolet or visible spectrum.
• the dye or pigment can be used to complement the properties of the barrier assembly, particularly where the barrier assembly transmits some frequencies while reflecting others.
• the barrier assembly can be treated with, for example, inks or other printed indicia such as those used to display product identification, orientation information, advertisements, warnings, decoration, or other information.
• Various techniques can be used to print on the barrier assembly, such as, for example, screen printing, inkjet printing, thermal transfer printing, letterpress printing, offset printing, flexographic printing, stipple printing, laser printing, and so forth, and various types of ink can be used, including one and two component inks, oxidatively drying and UV-drying inks, dissolved inks, dispersed inks, and 100% ink systems.
• the barrier assemblies of the invention can be used to inhibit the transmission of moisture vapor, oxygen or other gases in a variety of applications.
• the barrier assemblies of the invention are especially useful for encapsulating OLEDs, light valves such as liquid crystal displays (LCDs) and other electronic devices.
• a representative encapsulated OLED device 200 of the invention is shown in Fig. 4.
• the front or light- emitting side of device 200 faces downward in Fig. 4.
• Device 200 includes a visible light- transmissive barrier assembly 210 of the invention having an outer ITO layer (not shown in Fig. 4, but oriented so that it would face upward) that serves as an anode.
• Light emitting structure 220 is formed on barrier assembly 210 in contact with the outer ITO layer.
• Structure 220 contains a plurality of layers (not individually shown in Fig. 4) that cooperate to emit light downward through barrier assembly 210 when suitably electrically energized.
• Device 200 also includes conductive cathode 230 and metallic foil surround 250.
• Foil surround 250 is adhered to the back, sides and part of the front of device 220 by adhesive 240.
• An opening 260 formed in adhesive 240 permits a portion 270 of foil 250 to be deformed into contact with cathode 230.
• Another opening in foil 250 (not shown in Fig. 4) permits contact to be made with the anode formed by the outer ITO layer of barrier assembly 210.
• Metal foil 250 and barrier assembly 210 largely prevent water vapor and oxygen from reaching light emitting structure 220.
• a polyethylene naphthalate (“PEN”) support film was covered with a stack of acrylate and indium tin oxide (“ITO") layers arranged in a seven layer alternating acrylate/ITO/acrylate/ITO/acrylate/ITO/acrylate configuration.
• the individual layers were formed as follows:
• the acrylate mixture was vacuum degassed prior to coating, and pumped at a flow rate of 3.0 ml/min through an ultrasonic atomizer operated at a frequency of 60 kHz (commercially available from Sonotek Corp.) into a heated vaporization chamber maintained at 275° C.
• the resulting monomer vapor stream condensed onto the plasma-treated film surface, and was electron beam-crosslinked using a single filament operated at 8 kV and 2.5 milliamps to form a 426 nm thick acrylate layer.
• Layer 2 The web direction was reversed inside the chamber, and an ITO inorganic oxide layer was sputter deposited atop a 20 meter length of the acrylate-coated web surface using a 90% hi2 ⁇ 3/10% Sn ⁇ 2 target (commercially available from Umicore
• the ITO was sputtered using 1500 watts of power, a gas mixture containing 134 seem argon and 3.0 seem oxygen at a pressure of 3 millitorr, and a web speed of 0.55 meters/minute to provide a 48 nm thick ITO layer deposited atop the Layer 1 acrylate.
• Layer 3 The web direction was again reversed. A second acrylate layer was coated and crosslinked on the same 20 meter web length using the same general conditions as for Layer 1, but with these exceptions. Plasma treatment was performed at 3000W using a titanium cathode and the Layer 2 argon/oxygen gas mixture, and the monomer flow rate was 1.1 ml/min. This provided a 104 nm thick acrylate layer atop Layer 2.
• Layer 4 The web direction was again reversed. Using the same conditions as for Layer 2, a 48 nm thick ITO layer was deposited atop Layer 3.
• the film also exhibited an oxygen transmission rate (determined in accordance with ASTM D-3985 and evaluated with either side of the film facing the test gas) that was below the 0.005 cc/m 2 /day lower detection limit rate of a MOCON OXTRANTM 2/20 oxygen transmission rate testing system (commercially available from MOCON Inc) when evaluated at 38° C and 90% RH, and below an average value of 0.030 cc/ m 2 /day when evaluated at 50° C and 90% RH.
• Example 1 The barrier assembly of Example 1 was immersed in liquid nitrogen, fractured in half and examined in cross-section using a scanning electron microscope.
• Fig. 5 shows the resulting photomicrograph.
• Support 312, first polymer layer 314, visible light- transmissive inorganic barrier layers 316, 320 and 324, second polymer layers 318 and 322 and third polymer layer 326 can clearly be seen in Fig. 5.
• Example 2 [0048] A seven layer stack was prepared in the same manner as Example 1, but using
• SR-368D mixed acrylate mixture (commercially available from Sartomer Co. as a 50:50 mixture of SR-351 trimethylolpropane triacrylate and SR-368 tris (2-hydroxyethyl) isocyanurate triacrylate) and using no plasma treatment in the formation of Layers 3, 5, and 7.
• the estimated Tg of SR-368D is 167° C, based on an arithmetic average of the 62° C Tg of SR-351 and the 272° C Tg of SR-368.
• 100% IRR-214 acrylate without the EBECRYL 170 acrylated acidic adhesion promoter for each of Layers 1, 3, 5 and 7, and a plasma treatment performed at 2000W using a silicon cathode and the Layer 2 argon/oxygen gas mixture while depositing Layers 3, 5, and 7.
• Example 5 Effect of substrate Tg on WVTR [0054]
• Several substrates having various glass transition temperatures were covered with a three layer stack of SiAlO inorganic oxide and a commercial barrier polymer (SARANTM F-278, commercially available from Dow Chemical Company) arranged in an inorganic oxide/barrier polymer/inorganic oxide configuration.
• SARANTM F-278 commercially available from Dow Chemical Company
• sections of poly methyl pentene, polypropylene, PET and poly ether sulfone film substrates were spliced together end-to-end to make a single roll.
• the individual inorganic oxide and barrier polymer layers were formed on these substrates as follows: [0055] (Layer 1) The spliced roll was loaded into a roll-to-roll sputter coater.
• the deposition chamber was pumped down to a pressure of 2x10 "6 Torr.
• a 60 nm thick SiAlO inorganic oxide layer was deposited atop the substrate films by reactively sputtering a Si- Al (95/5) target (commercially available from Academy Precision Materials) using 2 kW and 600V, a gas mixture containing 51 seem argon and 30 seem oxygen at a pressure of 1 millitorr, and a web speed of 0.43 meters/minute.
• Layer 3 The polymer coated web was loaded into the vacuum coater. Using the same conditions as for Layer 1, a second SiAlO inorganic oxide layer was deposited atop Layer 2.
• the inorganic oxide was ITO and the polymers were formed from the ingredients set out below in Table 2, with the amount of each ingredient being shown as parts by weight in the formulation: Table 2
• Epoxy novolac diacrylate diluted with 30% trimethylolpropane triacrylate and 5% hydroxyethyl methacrylate (commercially available from UCB Chemicals Corp.).
• (Layer 1) The five formulations shown in Table 2 were coated on successive sections of the PET film substrate using a Model CAG-150 microgravure coater and a 150R knurl at a line speed of 6.1 m/min. The coatings were cured using a 6 kW Fusion H bulb (commercially available from Fusion UV Systems) operating at 100% power.
• (Layer 2) The coated film substrate was loaded into a sputter coater and pumped down to a base pressure of 2x10 "6 Torr.
• a 40 nm thick ITO inorganic oxide layer was deposited atop the Layer 1 formulations using 300 W and 420 V and a 90/10 tin oxide/indium oxide target (commercially available from Arconium Specialty Alloys), a gas mixture containing 30 seem argon and 8 seem oxygen at a pressure of 4 miUitorr, and a web speed of 0.127 meters/minute.
• Layer 3 and Layer 4 Using the same conditions as for Layer 1 and Layer 2 respectively, a second polymer layer was coated atop Layer 2 to form Layer 3 and a second ITO layer was deposited atop Layer 3 to form Layer 4.
• a laminated barrier assembly was assembled using an optical adhesive to adhere together in face-to-face fashion two barrier assemblies having six layer stacks on PET substrates.
• the completed laminated barrier assembly had a PET/polymer 1/SiAlO/ polymer 2/SiAlO/polymer 2/SiAlO/o ⁇ tical adhesive/SiAlO/polymer 2/SiAlO/ polymer 2/SiAlO/polymer 1/PET configuration.
• the barrier assemblies were formed and laminated together as follows:
• Polymer 1 had a 122.8° C Tg as determined using photodifferential scanning calorimetry
• Example 5 a 60 nm thick SiAlO inorganic oxide layer was deposited atop Layer 1.
• Layer 3 Using the conditions described for Layer 1 but with a 4.6 m/min coating speed, Layer 2 was coated with Formulation 7 (shown below in Table 4) and cured to provide a layer identified as "Polymer 2". Polymer 2 has a 90° C Tg.
• SiAlO was deposited atop Layer 5 to form Layer 6, thereby providing a barrier assembly having a PET/Polymer 1/SiAlO/ Polymer 2/SiAlO/Polymer 2/
• the resulting top-surface conducting barrier was cut into 22 x 22 mm squares using an X-ACTOTM knife (commercially available from Hunt Corporation). After rinsing with acetone and air-drying, the squares were cleaned in an oxygen plasma using a MICRO-RIETM Series 80 plasma system (commercially available from Technics, Inc.) and 4 minutes exposure at 50 watts power and 200 miUitorr oxygen pressure. An aqueous 1% solids solution of BAYTRONTM P 4083 polythiophene (commercially available from Bayer Corporation) was spun coat at 2500 rpm for 30 seconds onto the cleaned squares.
• the squares were held in place on the spin coater vacuum chuck by first placing a 22 x 22 x 1 mm glass slide on the vacuum chuck, applying vacuum to hold the glass slide in place, adding a drop of methanol to the top of the glass slide, placing the cleaned square atop the methanol and aligning the edges of the square with the edges of the glass slide.
• the methanol filled the space between the glass slide and the square and held the square in place during the spin coating operation.
• the coated squares were dried on a 70° C hot plate under a nitrogen atmosphere. [0076]
• the coated squares were transferred to a bell jar evaporation chamber and evacuated to about 10 ⁇ 6 torr.
• the following layers were thermally vapor-deposited in sequence on the coated squares through a shadow mask containing a 19.5 mm square opening:
• (Layer 1) A 2245 A thick layer of 4,4',4"-tris(N-(3-methylphenyl)-N- phenylamino)triphenylamine, ("MTDATA”, commercially available from H. W. Sands Corp.) doped with 7% tetrafluorotetracyanoquinodimethane ("FTCNQ”, commercially available from Tokyo Kasei Kogyo Co., Tokyo, Japan).
• (Layer 2) A 300 A thick layer of N,N'-di(naphthalen-l-yl)-N,N'- diphenylbenzidine (“alpha-NPB”, commercially available as OPD7534 from H. W. Sands
• the vapor-coated squares were transferred to glove box that contained a thin film evaporation chamber ("Edwards 500", commercially available from BOC Edwards) for the thermal deposition of cathodes.
• Edwards 500 commercially available from BOC Edwards
• a 1000 A thick calcium layer using a target commercially available from Alfa-Aesar Co.
• a 2000 A thick silver layer using a target commercially available from Alfa-Aesar Co.
• the devices were encapsulated with copper foil as described in copending U.S. Patent Application Serial No. 10/324,585 filed December 19, 2002.
• An approximately 50 x 100 mm piece of 3MTM Thermo-Bond Film 845 EG thermal laminating film (0.06 mm adhesive thickness) was marked on its release liner side with a 2 x 8 grid of 25 mm squares.
• a 6 mm circular hole was cut in the center of each 25 mm square using a handheld paper punch.
• the perforated thermal laminating film was placed onto an approximately 125 x 75 mm piece of 0.05 mm thick Cu foil (commercially available from McMaster-Carr Supply Co.) with the adhesive side contacting the foil, then placed on a 76 x 229 x 0.64 mm aluminum plate (commercially available from the Q-panel Company) with the release liner side contacting the aluminum plate.
• the resulting assembly was fed three times in succession through a TDE Systems Model HL-406 2-roll thermal laminator (commercially available from Kmart Corp.) operated at approximately 102 ° C to laminate the adhesive film to the Cu foil and deform the foil into the 6 mm hole in the adhesive.
• the laminated Cu foil was removed from the aluminum carrier plate, cut with scissors into 25 mm squares, and brought into the glove box containing the green emitting OLED devices.
• the 25 mm squares of laminated Cu foil were trimmed with scissors to about 20 mm square such that the 6 mm hole in the adhesive layer remained at the approximate center of the square.
• the release liner was then removed and the exposed adhesive layer placed against the cathode side of one of the 22 mm square OLED devices with the 6 mm hole through the adhesive layer approximately centered over the cathode of the OLED device, and with the laminated Cu foil square rotated by 45° with respect to the OLED substrate such that the corners of the laminated Cu foil square lined up with and extended beyond the approximate midpoint of the edges of the OLED substrate.
• the resulting assemblies were held together using tweezers and placed on a 100° C hotplate for about 20 seconds to cause the laminated Cu foil to adhere to the OLED substrate.
• the corners of the Cu foil were then folded over the front of the OLED device and laminated thereto in the inert nitrogen atmosphere of the glove box by passing the resulting assembly through a BESTECHTM Model 29622 roll thermal laminator (commercially available from Rose Art Industries) operated at about 100° C.
• a BESTECHTM Model 29622 roll thermal laminator commercially available from Rose Art Industries operated at about 100° C.
• anode connections to the encapsulated OLED were made by contacting an exposed ITO portion on a corner of the device and cathode connections were made by contacting the Cu foil.
• green light was emitted from the device.

Landscapes

• Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Laminated Bodies (AREA)
• Electroluminescent Light Sources (AREA)
• Heat Sensitive Colour Forming Recording (AREA)
• Physical Vapour Deposition (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (2)

Family

ID=33097060

Family Applications (1)

Country Status (8)

Cited By (26)

Families Citing this family (262)

Family Cites Families (64)

• 2003
  • 2003-04-02 US US10/405,284 patent/US7018713B2/en not_active Expired - Lifetime
• 2004
  • 2004-03-31 EP EP16175849.5A patent/EP3121003A1/en not_active Withdrawn
  • 2004-03-31 WO PCT/US2004/009956 patent/WO2004089620A2/en not_active Ceased
  • 2004-03-31 KR KR1020057018768A patent/KR101119702B1/ko not_active Expired - Fee Related
  • 2004-03-31 EP EP10182971.1A patent/EP2277698B1/en not_active Expired - Lifetime
  • 2004-03-31 EP EP04749603.9A patent/EP1613468B1/en not_active Expired - Lifetime
  • 2004-03-31 JP JP2006509551A patent/JP5117717B2/ja not_active Expired - Fee Related
  • 2004-03-31 CN CN2004800092597A patent/CN1771127B/zh not_active Expired - Lifetime
  • 2004-04-01 MY MYPI20041201A patent/MY135796A/en unknown
  • 2004-04-01 TW TW093109106A patent/TWI357915B/zh not_active IP Right Cessation
• 2005
  • 2005-11-14 US US11/272,929 patent/US7486019B2/en not_active Expired - Lifetime
• 2009
  • 2009-01-30 US US12/363,457 patent/US7980910B2/en not_active Expired - Lifetime
  • 2009-11-13 US US12/617,818 patent/US7940004B2/en not_active Expired - Fee Related
• 2010
  • 2010-01-13 US US12/686,801 patent/US20100119840A1/en not_active Abandoned
• 2011
  • 2011-02-28 JP JP2011042243A patent/JP5702188B2/ja not_active Expired - Fee Related

Also Published As

Similar Documents

Legal Events