HK1138465B

HK1138465B - El element containing a semitransparent metal foil and production method and use

Info

Publication number: HK1138465B
Application number: HK10104239.1A
Authority: HK
Inventors: Thilo-J. Werners; Michael Heite; Thomas-Hermann Kessler; Klaus Reinartz
Original assignee: Bayer Materialscience Ag
Priority date: 2006-12-07
Filing date: 2007-12-06
Publication date: 2015-04-10

Description

Electroluminescent element comprising a semitransparent metal foil, method for the production thereof and use thereof

Technical Field

The invention relates to a foil element consisting of an at least partially transparent carrier foil, a semi-transparent reflective layer, a further at least partially transparent foil, an electroluminescent element and a protective layer or a further foil, a method for producing the foil element, a three-dimensionally deformed foil element which can be produced by isostatic high-pressure deformation of the foil element according to the invention, a method for producing the three-dimensionally deformed foil element according to the invention, the foil element according to the invention and the use of the three-dimensionally deformed foil element according to the invention for forming decorative panels, coverings or display elements for land vehicles, ships and aircraft, in the formation of safety belt panels or warning indicator panels in land vehicles, ships and aircraft and warning indicator panels in buildings, in forming housing elements for moving or stationary electronic instruments, and in forming keyboards.

Background

Electroluminescent light emitting surfaces for mobile or stationary electronic devices are known in the prior art. Such electroluminescent luminous surfaces are often used as embedded components for backlighting display devices and operating units. Conventional electroluminescent luminous surfaces have polyester films as carrier material, on which a substantially transparent electrically conductive layer is deposited by a sputtering process. In addition, such electroluminescent luminous surfaces usually also comprise further layers, for example layers containing electroluminescent crystals, counter electrodes and protective layers. Since the layers used in the prior art for producing electroluminescent luminous areas tend to be brittle or cannot withstand deformation processes at high temperatures, conventional display devices are generally of planar construction, which can lead to a loss of legibility and operability of the information data, for example for objects having a three-dimensional geometry.

Three-dimensional electroluminescent displays have therefore been proposed in the prior art.

DE-a4430907 relates to a three-dimensional electroluminescent display with a transparent circular disc, to at least one side of which a light-transmitting layer is applied, to the sides of which at least one electroluminescent lamp is applied and to which substrates are molded on the electroluminescent lamp and the circular disc to form the complete three-dimensional electroluminescent display. The three-dimensional electroluminescent display is manufactured starting from a preformed disc. It is, however, also mentioned that the disc may also be formed afterwards, i.e. by conventional methods before the substrate is formed. However, DE-A4430907 contains no further information on suitable conventional processes.

DE-a10234031 relates to an electroluminescent luminous area comprising a capacitor structure with two electrodes arranged in parallel, wherein at least one of the electrodes is transparent and has a luminous substance arranged between the electrodes which can be excited by an electric field. The electroluminescent luminous area furthermore comprises a carrier layer with information data, which is produced from a freely deformable foil or a hard material with a three-dimensionally deformed surface and which, in a congruent manner in relation to its deformation at least in its information data area, has a coating of a first conductive layer, a pigment layer, an isolating and reflecting layer, a top electrode and optionally a protective layer. The electroluminescent luminous area is produced by first embossing a carrier layer of a freely deformable foil or a hard material which has been produced in a three-dimensionally deformed surface shape with information data and then providing it with a first conductive layer, a pigment layer, an isolating and reflecting layer, a rear electrode and optionally a protective layer. The three-dimensionally deformed foil body can then be back-injected with a plastic material to produce a carrier. In the case of a carrier layer consisting of a freely deformable foil, it is possible to achieve a deformation of the stamped foil body with the above-mentioned further layers, thermoforming being mentioned as a one-step deformation step in DE-a 10234031.

WO03/037039 relates to a three-dimensional electroluminescent display comprising a body and an electroluminescent device. The electroluminescent device is composed of a foil and an electroluminescent arrangement, the surface of the foil facing the electroluminescent arrangement having a theme to be displayed thereon. The electroluminescent device comprises a front electrode and a back electrode with a dielectric therebetween. The front electrode is assigned to and integrated with the layer reproducing the theme. Within the surface of an electroluminescent device there is a feed source in contact with the electrodes of the electroluminescent device. The body is made of a suitable plastic which can advantageously be processed in an injection moulding process. To manufacture the three-dimensional electroluminescent display, the electroluminescent device is first manufactured. For this, the foil serving as a carrier for the electroluminescent arrangement is first provided. The electroluminescent device is then reshaped by thermoforming, embossing, hollow embossing or solid embossing, preferably by thermoforming. After the deformation, the body is assigned to the rear side of the electroluminescent device, for example by back-injection molding the electroluminescent device with a material suitable for this purpose.

German application DE 102006031315, entitled "3D-EL HDVF-Element undhermsten und Anwendung", which is a prior publication but not a prior publication, relates to a three-dimensionally deformable foil Element constructed from an at least partially transparent carrier foil a, at least one electroluminescent Element B applied to the carrier foil, and a protective layer CA or foil CB, wherein the foil a is composed of at least one cold-stretchable foil material, which can be produced by isostatically high-pressure deformation of a flat foil Element composed of parts A, B and C at a processing temperature which is lower than the softening temperature of the part a of the foil Element. One characteristic of the three-dimensionally deformed foil element is that a three-dimensional deformation of the foil element containing all desired components is achieved, i.e. the electroluminescent element is applied, for example, before the three-dimensional deformation. The three-dimensionally deformed foil element is characterized in particular by the precisely positioned application of the electroluminescent element and optionally of an icon.

For decorative purposes it is desirable to provide electroluminescent foil elements that have a metallic appearance, i.e. a light-reflecting surface (metallic vision), when no current passes through them. Thus, when the current is switched off, the other layers of the foil element are not visible. Upon switching on the current, the foil element emits light, preferably colored light. The provision of such a foil element with a metal-looking surface can be achieved by said foil element having a semi-transparent reflective layer. Such foil elements are known in the prior art.

DE-a4208044 relates to an electroluminescent strip comprising an electroluminescent light-emitting element which has a layer consisting of a translucent film and is sealed in a water-impermeable material. The light-emitting strip includes a semi-transparent metal film layer directly adjacent to the electroluminescent light-emitting layer. The production of the electroluminescent strip is effected by so-called extrusion. The luminous strip disclosed in DE-A4208044 does not achieve a three-dimensional deformation.

DE-a4126051 relates to a security element with two electrically conductive layers and a layer with electroluminescent properties arranged between them. According to a preferred embodiment, two plastic films are provided, each with a thin aluminum layer on one side, and the zinc sulfide-based electroluminescent material is printed in the form of a strip on one of the metal layers. After this, the plastic film is laminated so that the electroluminescent material is located between the metal layers. Finally, the laminate obtained is cut into filaments corresponding to the electroluminescent strips. According to DE-a4126051, no three-dimensional deformation of the security element is achieved.

US3,497,750 relates to a flexible electroluminescent lamp comprising a dielectric layer made of plastic, in which electroluminescent phosphor particles in the form of fine powder are embedded, and a light-transmitting electrode, to one surface of which a film of an electrically conductive material is bonded. The light-transmissive electrode is coated with a light-transmissive plastic film extending beyond the sides of the phosphor/plastic layer. In addition, a metallized plastic film is applied to the other side of the phosphor/plastic layer, which film likewise extends beyond the side of the phosphor/plastic layer. The protruding parts of the plastic layers are fused together, whereby the metallized plastic film acts both as an electrode and as a protective cover for the electroluminescent lamp. No three-dimensional deformation of the electroluminescent lamp is mentioned in US3,497,750.

JP-a2000-348870 relates to a layered Electroluminescent (EL) display comprising an electroluminescent element composed of at least a surface electrode layer made of a thin metal film having a visible light transmittance of 5 to 60%, a light-emitting layer, a separation layer, and a back electrode layer. JP-a2000-348870 does not mention three-dimensional deformation of the electroluminescent element.

For prior art electroluminescent layer structures with a semi-transparent reflective layer, the latter is directly adjacent to the electroluminescent layer and usually constitutes the (at least partially) transparent electrode together with an at least partially transparent plastic layer.

A disadvantageous aspect of such a layer structure is that it is not possible to achieve a lossless three-dimensional deformation of such a layer structure. It is therefore an object of the present invention to provide a layer structure which is suitable for electroluminescence and can be deformed three-dimensionally in a lossless manner.

Disclosure of Invention

This object is achieved by providing a foil element consisting of:

a) an at least partially transparent carrier foil, component a, which consists of at least one cold-stretchable foil, which is provided with a graphic indication if required,

b) the semi-transparent reflective layer, component B,

c) an at least partially transparent foil, component C, which consists of at least one cold-stretchable foil,

d) at least one electroluminescent element, component D, which is applied on the at least partially transparent foil C and comprises the following components:

DA) an at least partially transparent electrode, i.e. the component DA,

DB) is filled with the required first barrier layer, i.e. component DB,

DC) a layer containing at least one light-emitting substance which can be excited by an electric field, i.e. a component DC,

DD) an optional further isolating layer, namely the component DD,

DE) back electrode, i.e. the component DE,

e) a protective layer, i.e., part EA, and/or a foil, i.e., part EB.

Furthermore, the foil element of the invention also comprises one or more conductive strips, preferably as part DF, i.e. part DF, to electrically contact part DA as well as part DE. The conductive strips may be applied in the form of silver bus bars, preferably produced from silver paste, and preferably produced by screen printing. A graphite layer may also be applied, preferably also by screen printing, before the silver bus is applied.

Thus, in a preferred embodiment of the invention, the foil element of the invention is composed of:

b) the semi-transparent reflective layer, component B,

c) the at least partially transparent foil, component C, is made of at least one cold-stretchable foil,

DA) an at least partially transparent electrode, i.e. the component DA,

DB) optionally a first barrier layer, i.e. the component DB,

DD) an optional further isolating layer, namely the component DD,

DE) back electrode, i.e. the component DE,

DF) one or more conductive strips, i.e. the part DF, for electrical contact with the part DA and the part DE,

e) a protective layer, i.e., part EA, and/or a foil, i.e., part EB.

In addition to the layers described (components A, B, C, D and E), the three-dimensionally deformed foil element of the invention may also have further layers. It is important that on both sides of the semi-transparent reflective layer B there is an at least partially transparent foil (a and C), wherein the foils a and C are directly adjacent to the semi-transparent reflective layer B. It was found that a foil element having the structure according to the invention, i.e. in particular having one at least partially transparent foil a and C on both sides of the semitransparent reflective layer B, can be deformed three-dimensionally in a non-destructive manner, in particular by isostatic high-pressure deformation of the foil element according to the invention, which is usually in planar form, usually at a process temperature below the softening temperature of the parts a and C of the foil element.

Detailed Description

Component A

The foil element of the invention comprises an at least partially transparent carrier foil, i.e. component a, which is composed of at least one cold-stretchable foil, which foil is provided with, where appropriate, an icon,

an "at least partially transparent carrier foil" is understood to include both transparent carrier foils and carrier foils which are light-transmitting but not completely transparent. Here, the transparent foil has a transmission of 100% of visible light, while the partially transparent foil has a transmission of < 100%, typically from 5% to < 100%, preferably from 10 to 99%, particularly preferably 50-A visible light transmission of 99%. According to the invention, the carrier foil is formed from at least one cold-stretchable foil material. This is necessary in order that the three-dimensionally deformed foil element can be produced by isostatic high-pressure deformation at a process temperature below the softening temperature of the component a. Suitable cold-stretchable foils are mentioned, for example, in EP-A0371425. Either thermoplastic or thermosetting at least partially transparent cold-stretchable foils may be used. It is preferable to use a cold-stretchable foil having a slight restoring force or no restoring force at room temperature and use temperature. Particularly preferred foils are at least one material selected from the group consisting of: polycarbonates, preferably based on bisphenol A, such as those sold by Bayer MaterialScience AG (BMS)A type; polyesters, in particular aromatic polyesters, such as polyalkylene terephthalates; polyamides, such as PA 6 or PA 6, 6-type, high strength "aramid films"; polyimides, such as poly (diphenyl ether pyromellitimide) based foils sold under the trade name Kapton; a polyarylate; organic thermoplastic cellulose esters, in particular the acetates, propionates and butyrates thereof, for example commercially available under the trade nameThe foil of (a); and polyfluorocarbons, in particular the copolymers formed from tetrafluoroethylene and hexafluoropropylene, known under the trade name FEB, which are available in transparent form. Preferred foils for the carrier foil are selected from: polycarbonates, e.g. Makrofol sold by Bayer MaterialScience AGA type; polyesters, in particular aromatic polyesters, such as polyalkylene terephthalates; and polyimides, e.g. commercially available under the trade name KaptonPoly (diphenyloxide pyromellitimide) -based foils. More particularly preferredAlternatively, a polycarbonate based on bisphenol A is used as foil, in particular under the name Bayfol manufactured by Bayer MaterialScience AGCR (polycarbonate/polybutylene terephthalate foil), MakrofolTP or MakrofolFoil of DE.

The at least partially transparent carrier foil used in the present invention may have a satin finished or rough surface on one side or may have a very glossy surface on both sides. The at least partially transparent carrier foil layer used in the present invention is typically 40-2000 μm thick. With greater layer thicknesses, the drastic reshaping carried out during isostatic high-pressure deformation often leads to brittle fracture of the material. The carrier foil preferably has a layer thickness of 50 μm to 500 μm, particularly preferably 100 μm to 400 μm, very particularly preferably 150 μm to 375 μm.

In a preferred embodiment, the at least partially transparent carrier foil is provided with an icon according to the application of the foil element according to the invention. Here, it may be an information symbol, so that for example letters, numbers, symbols or pictograms can be seen on the surface of the three-dimensionally deformed foil element. For graphic designs, it is preferably a printed graphic design, in particular a colour stamp. In a particularly preferred embodiment, the carrier foil used in the present invention is provided with an icon in the form of an opaque or semi-opaque colour stamp. These colour stamps may be realized by any process known to the person skilled in the art, for example by screen printing, offset printing, serigraphy, roto-printing, gravure printing or offset printing, all of which are known and customary in the art. The graphic design is preferably realized by applying the ink by screen printing, since by screen printing it is possible to apply a colored ink with a high layer thickness and good deformability.

The printing ink used for graphic design must be sufficiently deformable under the isostatic high-pressure deformation conditions. Suitable inks, in particular screen-printing inks, are known to the person skilled in the art. For example, an ink having a plastic ink vehicle, e.g., based on polyurethane, may be employed. These screen-printing inks have excellent adhesion to the foil of the carrier foil used according to the invention. Particularly preferably, screen-printing inks based on aqueous aliphatic polyurethane dispersions are used. Suitable inks are, for example, those obtainable fromAvailable under the trade name AquaPress PR from WeissenburgThe ink of (4). Other suitable screen-printing inks are inks based on high-temperature thermoplastics, in particularA screen printing ink manufactured by Weissenburg under the trade name Noriphari.

If the graphic symbols are located on the back of the foil C, these icons are only visible when the current is switched on, in a preferred embodiment, due to the semi-transparent reflective layer B. In contrast, when the current is switched off, only one metal surface is "visible".

The graphic symbols may also be overprinted on the front side of foil a, whereby the icons are permanently visible. Back illumination of the symbol or the entire surface may provide better discernability in the dark.

Component B

For component B, it is a semi-transparent reflective layer. Herein, a "semi-transparent reflective layer" in the context of the present application refers to a layer that is partially reflective to visible light and partially transmissive to visible light. As used herein, "visible light" refers to light having a minimum wavelength of about 360nm and a maximum wavelength of about 830nm, as known to those skilled in the art.

The semitransparent reflective layer B preferably has a visible light transmittance of generally 5 to 60%, preferably 10 to 40%.

The semi-transparent reflective layer may be, for example, a metal layer or a semi-transparent polymer printable reflective layer.

The layer thickness of the semi-transparent reflective layer B is typically 1-500nm, preferably 50-200nm, when a metal layer is used, and 500nm to about 5-10 μm when a semi-transparent polymer printable reflective layer is used.

Suitable metals from which the semi-transparent reflective layer may be constructed are known to those skilled in the art. The metal preferably used for forming the semi-transparent reflective layer is at least one metal selected from the group consisting of: aluminum, magnesium, tin, gold, silver, copper, zinc, nickel, chromium, cobalt, manganese, lead, titanium, iron, and tungsten. Particularly preferred metals for forming the semi-transparent reflective layer are aluminum and/or chromium. Mixtures of metals or one or more metal printing inks may also be employed.

Usually, a semitransparent reflective layer B is first applied to an at least partially transparent carrier foil a. However, it is equally possible to first apply the semitransparent reflective layer to the at least partially transparent foil C. Application can be carried out by processes known to the person skilled in the art which are suitable for producing preferably uniform thin metal foils free of surface irregularities. Suitable processes are, for example, PVD processes (physical vapor deposition), for example evaporation processes such as thermal evaporation (vapor deposition), electron beam evaporation, laser beam evaporation, arc evaporation and molecular beam epitaxy, sputtering or ion plating, CVD processes (chemical vapor deposition), such as thermal CVD, plasma-assisted CVD and metal-organic CVD (mocvd) or calendering.

Suitable process conditions for the above process are known to those skilled in the art.

Component C

For component C, it is an at least partially transparent foil composed of at least one cold-stretchable foil. In order to achieve a three-dimensional deformation of the foil element of the invention by an isostatic high-pressure deformation process, the foil C is preferably composed of those materials mentioned in the description of the component a. In this connection, in the foil element of the invention, the materials of the parts a and C may be the same or different (preferably each selected from the materials mentioned in the description of the carrier foil a). More preferably, the foils a and C are each composed of the same material in one foil element.

In a particularly preferred embodiment, the foil of the carrier foil a and the foil of the foil C are selected from at least one material from the group: polycarbonates, polyesters, polyamides, polyimides, polyarylates, organic thermoplastic cellulose esters, and polyfluorocarbons, with polycarbonates, polyesters, and polyimides being more particularly preferred.

Other preferred materials for the foil C are those mentioned in the description of the carrier foil a.

In a particularly very highly preferred embodiment, the foil of the carrier foil a and the foil of the foil C are polycarbonates, in particular based on bisphenol a, for example available from Bayer material science ag under the name BayfolCR (polycarbonate/polybutylene terephthalate foil), MakrofolTP or MakrofolFoil of DE.

The thickness of the foil C also corresponds to the preferred thickness described in the description of the carrier foil a.

The application of the second layer foil (a or C) to the second surface of the translucent metal foil B applied on the first layer foil (a or C) may be achieved by gluing by means of a process example known to the person skilled in the art. Suitable processes and adhesives are known to those skilled in the art.

Component D

The foil element of the invention comprises at least one electroluminescent element as component D applied on foil C.

The electroluminescent element includes the following components:

DA) an at least partially transparent electrode, i.e. the component DA,

DB) optionally a first barrier layer, i.e. the component DB,

DD) optionally a further isolating layer, i.e. component DD, and

DE) back electrode, i.e. component DE.

Furthermore, the electroluminescent element used according to the invention preferably also comprises a conductor track or conductor tracks as component DF for electrical contact with component DA and also with component DE. The conductive strips may be applied in the form of silver bus bars, preferably produced from silver paste, and preferably produced by screen printing. A graphite layer may also be applied prior to the application of the silver bus, again preferably by screen printing.

In a preferred embodiment of the present invention, the electroluminescent element used in the present invention is composed of:

DA) an at least partially transparent electrode, i.e. the component DA,

DB) optionally a first barrier layer, i.e. the component DB,

DD) an optional further isolating layer, namely the component DD,

DE) back electrode, i.e. the component DE,

DF) one or more conductive strips, i.e. the part DF, for electrical contact with the part DA as well as with the part DE.

The electroluminescent element may have other components in addition to the above components. For example, further layers may be present between the back electrode (component DE) and, if desired, a further isolating layer (component DD) (or, in the absence of said isolating layer, between component DE and component DC). In this case the component DD (or the component DC when there is no component DD) may adjoin a further structure comprising an at least partially transparent electrode, a further layer containing at least one light-emitting substance which can be excited by an electric field, and optionally a further isolating layer. This structure may, where appropriate, be repeated again, with the last part of the structure abutting the back electrode (part DE).

Suitable electroluminescent elements are known to the person skilled in the art. It was found that a foil element with at least one electroluminescent element for use in the invention can be deformed in a non-destructive manner by isostatic high-pressure deformation, so that a three-dimensionally deformed foil element can be obtained from a foil element of the invention by isostatic high-pressure deformation.

It is known to the person skilled in the art that the at least one electroluminescent element used in the present invention is in contact with a current source. In general, the at least one electroluminescent element has for this purpose terminals which are introduced into the lateral edges of the foil element according to the invention and are contacted there by a current source via contact aids. Suitable contact aids are, for example, crimping, clamps, conductive glue, rivets, screws and other means known to the person skilled in the art. The driving of the electroluminescent elements can be effected in a conventional manner known to the person skilled in the art.

Generally, the electroluminescent element operates under alternating current. For generating the alternating current, an electroluminescent inverter (EL inverter) is used. Suitable EL converters are known to those skilled in the art and are commercially available.

As the electroluminescent element used in the foil element of the present invention as the component D, it is generally a thick film electroluminescent element (thick film AC-EL element) operating under an alternating current. These thick-film AC-EL elements have the advantage that higher voltages are used, typically in excess of 100 volts peak-to-peak, preferably in excess of 100 volts peak-to-peak to 140 volts peak-to-peak, at frequencies in the range of several hundred hertz up to kilohertz (1000Hz), preferably 250-800Hz, particularly preferably 250-500 Hz; and there is little ohmic power loss during the formation of the layer containing at least one light-emitting substance which can be excited by an electric field, i.e. the component DC (dielectric layer). The electrical conductivity of the electrodes (components DA and DE) should therefore be as uniform as possible, but little specific current loading occurs. However, it is preferable to use a bus bar that conducts efficiently to reduce the voltage drop.

In general, the electroluminescent element (component B) used in the foil element of the invention is in the range of 10-500cd/m²Preferably 10-100cd/m²The brightness of the light source. In this case, a use half-life of usually at least 2000 hours can be achieved when microencapsulated ZnS electroluminophores are used in the layer comprising the at least one field-excitable luminescent substance. In principle, it is preferred that such electroluminescent elements are operated at alternating voltages having a harmonic curve. Transient voltage pulses should be avoided. In particular, the switching-on and switching-off steps are preferably arranged such that no ultra-high voltage pulses are generated which would damage the layer containing the at least one light-emitting substance (dielectric) which can be excited by the electric field and, where possible, also the individual light-emitting substances (electroluminescent substances). The reduction in brightness over the lifetime, the so-called half-life, i.e. the time to half the original brightness, can be balanced by readjusting the supply voltage or, where appropriate, the frequency. For this purpose, for readjusting the luminescence, for example, external photodiodes measuring the electroluminescence can be used. The luminous color of the electroluminescence can also be influenced within a certain range with the change of the frequency.

In another preferred embodiment of the present invention, the foil element of the present invention may comprise a LED element in addition to said at least one electroluminescent element. Which is preferably an SMD-LED element. Suitable LED elements are known to the person skilled in the art and are commercially available.

A further subject of the invention is therefore a foil element consisting of the components A, B, C, D and E and additionally at least one LED element, preferably at least one SMD-LED element, as component F.

The SMD-LED module unit is preferably arranged on the back side of the foil element consisting of the parts A, B, C, D and E, for example by gluing by means of processes known to the person skilled in the art and adhesives known to the person skilled in the art.

The LED element usually has a punctiform, very high-brightness emission and can therefore produce a higher emission intensity than a planar electroluminescent element, for example, after an indication region provided in a semi-transparent and signal-effective manner. The inventive foil element with LED elements can thus be effectively used as an alarm signal element. Furthermore, in another preferred embodiment, the semi-translucent light-emitting area is equipped with a diffuser element by means of printing technology and/or dispenser technology, whereby the SMD-LED element has broad radiation characteristics and can thus be used as an optical signal for alarm situations, such as an indication of too high a temperature or too little oil or a failure of the ABS braking system, etc. Suitable diffuser elements are known to those skilled in the art and are commercially available.

The electroluminescent element used in the present invention has an electrode which is at least partially transparent. In this connection, an "at least partially transparent" electrode is understood to be a completely transparent electrode or an electrode which is transparent to light but not completely transparent.

The at least partially transparent electrode is typically a planar electrode composed of one or more inorganic or organic conductive materials. Suitable at least partially transparent electrodes which can be used in the present invention are all electrodes known to the person skilled in the art for the manufacture of electroluminescent elements which are not destroyed by the deformations described when manufacturing the three-dimensionally deformed foil element of the present invention by isostatic high-pressure deformation. Thus, while the conventional Indium Tin Oxide (ITO) sputtered layers on thermally stable polyester foils mentioned in the prior art are in principle suitable, they are not preferred. A polymer conductive high light transmission coating or a specially designed screen printed layer is preferably used.

The at least partially transparent electrode used in the present invention is thus preferably selected from the group consisting of an ITO screen-printed layer, an ATO (antimony tin oxide) screen-printed layer, a non-ITO screen-printed layer (the term "non-ITO" includes all screen-printed layers not based on Indium Tin Oxide (ITO)), i.e. an intrinsically conductive polymer layer with conductive pigments of generally nanometer size, such as the ATO screen-printed paste from DuPont, labeled 7162E or 7164, an intrinsically conductive polymer system such as the Orgacon system of Agfa, the Baytron poly (3, 4-ethylenedioxythiophene) system of h.c. starck GmbH, the system labeled organometals (PEDT conductive polymers, polyethylenedioxythiophene) of ormon, the conductive coating system or the printing ink system of Panipol OY, and, where appropriate, highly flexible binders, such as those based on PU (polyurethane), PMMA (polymethylmethacrylate), PVA (polyvinylalcohol), polyvinyl alcohol (co-l), poly (co-ethylenedioxythiophene), Modified polyaniline adhesive. The material in the at least partially transparent electrode of the electroluminescent element preferably employs the Baytron poly (3, 4-ethylenedioxythiophene) system from h.c. starck GmbH.

According to the invention, the printing pastes used for the production of the partially transparent electrode DA are preferably formulated using Baytron P, Baytron PH, Baytron P AG, Baytron P HCV4, Baytron P HS, Baytron PH500, Baytron PH 510 or any mixtures thereof, all in a proportion of 10 to 90 wt.%, preferably 20 to 80 wt.%, particularly preferably 30 to 65 wt.%, relative to the total weight of the printing paste. The solvent may use Dimethylsulfoxide (DMSO), N-dimethylformamide, N-dimethylacetamide, ethylene glycol, glycerol, sorbitol, methanol, ethanol, isopropanol, N-propanol, acetone, butanone, dimethylaminoethanol, water, or a mixture of two, three or more of the above solvents. The solvent content in the printing paste can vary within wide limits. Thus, while 55-60% by weight solvent may be included in a slurry formulation according to the present invention, about 35-45% by weight of a solvent mixture of the two solvents is used in another formulation of the present invention. Furthermore, Silquest A187, Neo Rez R986, Dynol604 and/or mixtures of two or more of these substances can also be contained as interface additives and adhesion activators. Their content is preferably 0.3 to 2.5% by weight relative to the total weight of the printing paste.

About 0.5-6 wt.%, preferably 3-5 wt.% of UD-85, Bayhydrol PR340/1, Bayhydrol PR135, or any mixture thereof may be included as a binder in the formulation. For the polyurethane dispersion used in the present invention, it is preferably an aqueous polyurethane dispersion, wherein the polyurethane dispersion constitutes the binder of the conductive layer after the layer has dried.

Particularly preferred formulations of the printing pastes for manufacturing the partially transparent electrode DA according to the present invention are:

substance(s)	Content/weight%	Content/weight%
			Baytron PHS(HC Starck)	33.0	48.0
Silquest A 187(Osi Specialties)	0.4	0.5
			N-methyl pyrrolidone	23.7	14.4
Diethylene glycol	26.3	20.7
			Proglyde/DMM	12.6	12.4
UD-85(Lanxess)	4	4

In addition to the above-described formulations for the partially transparent electrode DA, the following commercially available ready-made printing pastes listed by way of example can also be used in the present invention as final formulations: orgacon EL-P1000, EL-P3000, EL-P5000 or EL-P6000 series from Agfa, preferably the EL-P3000 and EL-P6000 series (especially for deformable applications).

Typically, the at least partially transparent electrode of the electroluminescent element is directly connected to the at least partially transparent foil C.

The electroluminescent element used in the present invention comprises, as component DC, a layer containing at least one light-emitting substance which can be excited by an electric field, in addition to the at least partially transparent electrode (component DA). This layer is usually applied on the first isolating layer (component DB), which is present in the appropriate case, or on the at least partially transparent electrode when this layer is not present. For the electric field excitable luminescent substance (emitter) in the layer (component DC), which is preferably ZnS, it is usually doped with copper, manganese and/or phosphorus, preferably with copper and/or manganese, and preferably also with at least one element selected from the group consisting of chlorine, bromine, iodine and aluminum.

The ZnS crystals are preferably microencapsulated with a thin transparent layer to increase the lifetime of the luminescent substance. Such microencapsulation is known in the art and is known to those skilled in the art. EP-A-455401, for example, discloses ｃA microencapsulation of titanium dioxide or aluminum oxide. In this case, each ZnS particle is substantially completely provided with a substantially transparent continuous metal oxide coating. The layer (component DC) comprises the above-mentioned, where appropriate doped ZnS crystals, preferably microencapsulated as described above, preferably in an amount of 40 to 90 wt.%, preferably 50 to 80 wt.%, particularly preferably 55 to 70 wt.%, relative to the weight of the slurry. As adhesive, one-component and preferably two-component polyurethanes can be used. According to the invention, preference is given to materials produced by Bayer MaterialScience AG, for example raw lacquers of the Desmophen and Desmodur series, preferably Desmophen and Desmodur, or raw lacquers of the Lupranate, Lupranol, Pluraco or Lupraphen series produced by BASF AG. As the solvent, ethoxypropyl acetate, ethyl acetate, butyl acetate, methoxypropyl acetate, acetone, butanone, methyl isobutyl ketone, cyclohexanone, toluene, xylene, solvent naphtha 100, or any mixture of two or more of these solvents can be used, and the amount of the solvent used is 1 to 50% by weight, preferably 2 to 30% by weight, and particularly preferably 5 to 15% by weight, relative to the total weight of the slurry. In addition, additives for improving flow properties and leveling may be included in an amount of 0.1 to 2% by weight. Examples of levelling agents are Additol XL480 dissolved in 3-methoxybutyl acetate (Butoxyl) in a mixing ratio of 40: 60 to 60: 40. As further additives, it is also possible to include 0.01 to 10 wt.%, preferably 0.05 to 5 wt.%, particularly preferably 0.1 to 2 wt.%, relative to the total weight of the paste, of rheological additives which reduce the sedimentation behavior of pigments and fillers in the paste, such as BYK 410, BYK 411, BYK 430, BYK 431 or any mixtures thereof.

Typically for the layer (component DC) it is a dielectric material. The material may beFor example ZnS, typically doped with copper, manganese and/or phosphorus, preferably with copper and/or manganese, and preferably also simultaneously with at least one element selected from chlorine, bromine, iodine and aluminum; or ZnS and BaTiO doped with copper, manganese and/or phosphorus in general, preferably copper and/or manganese, and preferably also doped with at least one element selected from chlorine, bromine, iodine and aluminum simultaneously₃And highly flexible adhesives, for example those based on PU, PMMA, PVA, in particular Mowiol and Poval from Kuraray Europe GmbH, or Polyviol from Wacker AG, or PVB, in particular Mowital from Kuraray Europe GmbH, or Pioloform from Wacker AG, in particular Pioloform BR18, BM18 or BT 18.

Two formulations of the printing pastes according to the invention which are particularly preferred for producing the electroluminescent phosphor layer as component DC comprise the following substances:

substance(s)	Content/weight%	Content/weight%	Content/weight%
				Pigment (Osram Sylvania)	52.44	69.7	61.05
Desmophen D670(BMS)	21.19	11.88	12.8
				Desmodur N75MPA(BMS)	15.24	8.11	12.4
Ethoxy propyl acetate	10.67	10	13.5
				Additol XL480 (50% by weight in 3-methoxybutyl acetate)	0.46	0.3	0.25

In addition to the components DA and DB, the electroluminescent element can also comprise, as component DD, a separating layer, which is usually applied to the layer containing at least one light-emitting substance which can be excited by an electric field. Suitable materials for the barrier layer are, for example, barium titanate (BaTiO)₃). Other barrier materials are known to those skilled in the art from the literature, for example: BaTiO 2₃、SrTiO₃、KNbO₃、PbTiO₃、LaTaO₃、LiNbO₃、GeTe、Mg₂TiO₄、Bi₂(TiO₃)₃、NiTiO₃、CaTiO₃、ZnTiO₃、Zn₂TiO₄、BaSnO₃、Bi(SnO₃)₃、CaSnO₃、PbSnO₃、MgSnO₃、SrSnO₃、ZnSnO₃、BaZrO₃、CaZrO₃、PbZrO₃、MgZrO₃、SrZrO₃、ZnZrO₃Or a mixture of two or more of these fillers. According to the invention, BaTiO is preferably used as filler in the slurry for producing the separating layer₃Or PbZrO₃Or mixtures thereof, preferably in an amount of from 5 to 80% by weight, preferably from 10 to 75% by weight, particularly preferably from 40 to 70% by weight, based on the total weight of the pulp.

As binder for this layer, one-component or preferably two-component polyurethane systems can be used, preferably from Bayer MaterialScience AG, particularly preferably Desmodur and Desmophen; from Degussa AG (Evonik), preferably Vestanat, again particularly preferably Vestanat T and B; or from Dow Chemical company, again preferably Vorastar.

As the solvent, for example, ethyl acetate, butyl acetate, 1-methoxy-2-acetoxypropane, toluene, xylene, Solvesso 100, Shellsol A or a mixture of two or more of these solvents can be used. In addition, additives such as leveling agents and rheological additives may also be added to improve performance. Preferably containing 0.5-2.5% by weight, relative to the printing paste, of Additol XL480 or Silquest A187, Neo Rez R986, Dynol604 and/or mixtures of two or more of these substances.

Two formulations of printing pastes according to the invention which are particularly preferred for producing the release layer as part DD contain the following substances:

substance(s)	Content/weight%	Content/weight%	Content/weight%
				BaTiO₃	50	60	55.3
Desmophen 1800(BMS)	25	13	20.1
				Desmodur L67MPA/X(BMS)	13.7	13	9.4
Ethoxy propyl acetate	10	8	13.7
				Additol XL480	2.3	2	1.5

Further, the at least one electroluminescence element used in the present invention further includes a back electrode (part DD). If a separator layer is present, the electrodes are typically applied over the separator layer. If no separating layer is present, the back electrode is applied to the layer containing the at least one light-emitting substance which can be excited by an electric field.

For the back electrode, it is a planar electrode in the case of the at least partially transparent electrode, but it need not be transparent or at least partially transparent. The electrodes are usually composed of electrically conductive inorganic or organic materials, in which case preferably those materials are applied which are not damaged by the isostatic high-pressure deformation process applied for producing the three-dimensionally deformed foil element according to the invention. Suitable electrodes are thus in particular polymer conductive coatings. In this connection, the coatings already mentioned above in the description of the at least partially transparent electrode can be used. Furthermore, non-at least partially transparent polymeric conductive coatings known to those skilled in the art may also be used.

Suitable materials for the back electrode are thus preferably selected from metals such as silver, carbon, ITO screen printed layers, ATO screen printed layers, non-ITO screen printed layers, i.e. intrinsically conductive polymer layers with conductive pigments of generally nano-size, e.g. ATO screen printing pastes with the designation 7162E or 7164 from DuPont, intrinsically conductive polymer systems such as Orgacon of AgfaSystem, Baytron of H.C.Starck GmbHPoly (3, 4-ethylenedioxythiophene) systems, the system of Ormecon, which is designated as organometallic (PEDT conductive polymer, polyethylenedioxythiophene), the conductive coating system of Panipol OY and the printing ink system, and, where appropriate, highly flexible binders, for example binders based on PU (polyurethane), PMMA (polymethyl methacrylate), PVA (polyvinyl alcohol), modified polyaniline, where, to improve the electrical conductivity, the abovementioned materials can be mixed with metals such as silver or carbon and/or layers composed of these materials can be added.

The formulation of the printing paste for the back electrode may be identical to the formulation of the partially transparent electrode.

However, in addition to this formulation, the following formulation may also be used for the back electrode according to the present invention.

For the preparation of the printing pastes for the production of the back electrode, conductive polymers Baytron P, Baytron PH, Baytron PAG, Baytron P HCV4, Baytron HS, Baytron PH500, Baytron PH 510 or any mixtures thereof, each in amounts of 30 to 90% by weight, preferably 40 to 80% by weight, particularly preferably 50 to 70% by weight, based on the total weight of the printing paste, are used. As the solvent, dimethyl sulfoxide (DMSO), N-dimethylformamide, N-dimethylacetamide, ethylene glycol, glycerol, sorbitol, methanol, ethanol, isopropanol, N-propanol, acetone, butanone, dimethylaminoethanol, water, or a mixture of two, three, or more of the above solvents can be used. The amount of solvent used may vary within wide limits. Thus, 55-60% by weight of solvent may be included in a slurry formulation according to the invention, while about 40% by weight of a solvent mixture of three solvents is used in another formulation of the invention. In addition, 0.7 to 1.2% by weight of Silquest A187, Neo Rez R986, Dynol604 or a mixture of two or more of these substances may be contained as an interface additive and a bonding activator. The binder may contain, for example, 0.5 to 1.5% by weight of UD-85, Bayhydrol PR340/1, Bayhydrol PR135, or any mixture thereof.

In another embodiment of the present invention, graphite may be filled in the back electrode. This can be achieved by adding graphite to the above formulation.

In addition to the above-described formulations for the back electrode, the commercially available ready-to-use printing pastes listed below by way of example can also be used in the present invention as final formulations: orgacon EL-P1000, EL-P3000, EL-P5000 or EL-P6000 series from Agfa, preferably EL-P3000 and EL-P6000 series (for deformable applications). Graphite may also be added here.

Especially for the back electrode, print pastes of the Orgacon EL-P4000 series can be used, especially Orgacon EL-P4010 and EL-4020. The two may also be mixed in any ratio. Orgacon EL-P4010 and EL-4020 already contain graphite.

Commercially available graphite pastes can also be used as the back electrode, such as graphite paste from Acheson, in particular Electrodag 965 SS or Electrodag 6017 SS.

The formulation of the printing paste according to the invention, which is particularly preferred for producing the back electrode DE, comprises the following substances:

substance(s)	Content/weight%	Content/weight%
			Baytron PHS	58.0	64.0
Silquest A187	2.0	1.6
			NMP (e.g. BASF)	17.0	14.8
DEG	10.0	5.9
			DPG/DMM	10.0	10.2
UD-85	3.0	3.5

The manufacture of the electroluminescent element can be achieved by applying said individual layers, for example by means of a so-called thick-film process as known in the art.

The application of the electroluminescent element layer on the foil C is effected by processes known to the person skilled in the art. The connection of the electroluminescent element to the foil C is generally effected by direct application to the foil C, for example by screen printing.

In order to contact the electrically conductive layers DA with the DE and to supply them with an electric current, the two layers are preferably provided with an arbitrarily configured conductive strip. This can be done in one print in both layers, or in two separate print processes for the front and back electrodes. As the printing paste, commercially available systems known to those skilled in the art, for example, silver conductive paste from Acheson, such as Electrodag 725A (6S-61), Electrodag 418 SS, or Electrodag PF-410, can be used.

Component E

In addition to the components A, B, C and D, the foil element of the invention also comprises a protective layer (component EA) in order to prevent the electroluminescent element or, where appropriate, the icons present, from being destroyed. Suitable materials for the protective layer are known to the person skilled in the art. Suitable protective layers EA are, for example, high-temperature-resistant protective lacquers, such as protective lacquers containing polycarbonate and binders. An example of such protective lacquers is that fromNoriphan of Wei beta enburgHTR。

Alternatively, the protective layer may also be formulated based on polyurethane. For this purpose, polyurethanes from Bayer MaterialScience AG may be used. The formulation may also have a filler. Suitable for this are all fillers known to the person skilled in the art, for example based on inorganic metal oxides such as TiO₂And ZnO, lithopone, and the like. In addition, the formula can also comprise a leveling agent and a rheological additive. As the solvent, for example, ethoxypropyl acetate, ethyl acetate, butyl acetate, methoxypropyl acetate, acetone, butanone, methyl isobutyl ketone, cyclohexanone, toluene, xylene, solvent naphtha 100, or a mixture of two or more of these solvents can be used.

Particularly preferred formulations of the protective lacquer EA according to the invention comprise the following substances:

substance(s)	Content/weight%
		Desmodur	18
Additol XL480	1
		Desmophen	21.85
Ethoxypropyl acetate	4.15
		TiO₂	55

Depending on the application, the foil element of the invention may have a foil (component EB) in addition to components A, B, C and D, instead of the protective layer (component EA). Suitable foils are those known as carrier foils (component a). The foil may be applied, for example, by lamination or adhesion.

The foil element of the invention, which is usually in planar form, is three-dimensionally deformable by isostatically high pressure deformation at a processing temperature below the softening temperature of the components a and C, whereby a corresponding three-dimensionally deformed foil element is obtained. Suitable isostatic high-pressure deformation processes are mentioned, for example, in EP-A0371425. According to the invention, by the structure consisting of the parts A, B, C, D and E as described above, it is ensured that a three-dimensional deformation of the foil element of the invention, which is generally planar in form, can be achieved by isostatic high-pressure deformation without damaging the individual parts of the foil element, in particular the function of the lamp and the semi-transparent reflective layer of the electroluminescent element.

The layers (parts A, B, C, D and E) in the foil element of the invention are matched in such a way that short circuits can be avoided. The protective layer (member E) on the back side has an effect that resistance to cracking deformation can be achieved. Since the generally planar form of the foil elements constructed from elements A, B, C, D and E can be deformed by isostatic high pressure deformation, it is particularly important to ensure good adhesion of the various layers of the foil element. This good adhesion is ensured by the composition of the individual layers (components A, B, C, D and E), in particular by using highly flexible adhesives, for example based on PU, PMMA, PVA, in the layers. The composition of the individual layers (elements A, B, C, D and E) ensures not only excellent layer adhesion between them, but also the extensibility required to perform the isostatic high-pressure deformation.

Another subject of the invention is thus a three-dimensionally deformed foil element constructed from the inventive foil element comprising parts A, B, C, D and E, which can be produced by isostatic high-pressure deformation of the inventive foil element at a treatment temperature below the softening temperature of parts a and C of the inventive foil element.

Preferred components A, B, C, D and E are given above, as well as preferred embodiments of the foil element of the present invention.

The three-dimensional foil element of the invention is characterized in that at least one electroluminescent element applied on the carrier foil and, if desired, an icon present on the transparent carrier foil are applied in a precisely positioned manner. This is important since the three-dimensionally deformed foil element according to the invention will for example be used for structuring surfaces, which requires a precise positioning of the information symbol. This precise positioning is achieved by a planar foil element having components A, B, C, D and E that are selected so that the planar foil element can be deformed in three dimensions by isostatic high-pressure deformation. It was found that said three-dimensional deformation by isostatic high-pressure deformation can be achieved in the presence of electroluminescent elements with the components DA, DB and, where appropriate, DC and DD, and in the presence of a translucent metal foil B.

The three-dimensionally deformed foil element according to the invention is dimensionally stable enough for many applications, so that the back-injection molding (Hinterspritzen) of the foil element with a suitable plastic, as proposed in the above-mentioned prior art, is not necessary. Thus, in a preferred embodiment, the present invention is directed to a three-dimensionally deformed foil element constructed from components A, B, C, D and E without any molded substrate, in particular without being back-injected with plastic.

In yet another preferred embodiment, the foil element can obviously also be back-injected with plastic. This is especially true when the three-dimensional stability of the entire structural part is strictly required and/or a high resistance to external forces is required. This is the case, for example, in case covers, panels and cover plates.

The foil element of the invention, which is generally planar in form, can be manufactured according to methods known to the person skilled in the art.

In a preferred embodiment, the method for manufacturing the foil element of the invention (before three-dimensional deformation) comprises the steps of:

ia) providing an at least partially transparent carrier foil a and optionally embossing icons on said transparent carrier foil,

ib) applying a semi-transparent reflective layer B on the at least partially transparent carrier foil a,

ic) applying an at least partially transparent foil C on said semi-transparent reflective layer B and optionally applying graphics on said at least partially transparent foil C,

id) applying at least one electroluminescent element D on said at least partially transparent foil C,

ie) a protective layer EA or a foil EB is applied over the at least one electroluminescent element D.

Step ia)

The manufacture of the at least partially transparent carrier foil a and the at least partially transparent foil C used in step ia) and step ic), respectively, is carried out according to methods known to the person skilled in the art. Furthermore, suitable carrier foils a and C are commercially available.

The application of the icons to the carrier foil a can likewise be effected by methods known to the person skilled in the art, for example by screen printing, offset printing, rotary printing, intaglio printing, ink-jet printing, tampon printing, laser printing or offset printing, which are customary and known in the art. The graphic design is preferably achieved by applying ink by screen printing.

Multiple printing, e.g. double printing, may be performed in order to obtain complete coverage without minimal transparent defects. To locate each print, a reference mark or three-point edge registration is typically used.

Step ib)

The semitransparent reflective layer B may be applied to the carrier foil a by methods known to the person skilled in the art. A method suitable for applying the semitransparent reflective layer B is given above. Examples of suitable methods are PVD processes, CVD processes and other suitable processes.

Step ic)

In step ic) a further at least partially transparent foil C is applied on the semi-transparent reflective layer B which has been applied on the carrier foil a optionally with icons. The application may be accomplished by any method known to those skilled in the art. In a preferred embodiment of the invention, the application of the foil C is effected by gluing. Suitable bonding methods and adhesives are known to those skilled in the art.

On the foil C, a graphic can be applied on the back side as required. The graphics may be applied by methods known to those skilled in the art, such as by screen printing, offset printing, rotary printing, gravure printing, ink jet, tampon printing, laser printing, or flexographic printing, all of which are known and conventional in the art. The graphic design is preferably achieved by applying ink by screen printing.

Step id)

The application of the electroluminescent element D onto the foil C in step id) can likewise be effected by processes known to the person skilled in the art. The connection of the electroluminescent elements D to the foil C can be effected in a manner known to the person skilled in the art, typically by direct application to the carrier foil, as described above, for example by screen printing.

Step ie)

In step ie), a protective layer EA or foil EB can likewise be applied to the at least one electroluminescent element by methods known to the person skilled in the art, likewise preferably by screen printing.

The isolating layer is also preferably applied by screen printing.

The foil element of the invention has the advantage that all layers of the EL lamp and all layers of the foil element, if appropriate with the desired graphic printing, are selected such that they can be applied by screen printing. In a preferred embodiment of the method of the invention, the stamping of the transparent base foil with the icon in step ia), the application of the electroluminescent element onto the, suitably stamped, carrier foil in step id), and the application of the protective layer onto the electroluminescent element in step ie), which are carried out where appropriate, are effected by screen printing. Steps ib) and ic) are generally carried out as separate steps by processes known to those skilled in the art. Step ia) can also be carried out after step ic) if desired, in order to optimize the process chain.

The foil element of the invention is suitable for producing a three-dimensionally deformed foil element by an isostatic high-pressure process.

Thus a further subject of the invention is a method of manufacturing a three-dimensionally deformed foil element, comprising:

i) the foil element of the present invention is manufactured,

ii) subjecting the inventive foil element obtained in step i) to isostatic high-pressure deformation at a process temperature below the softening temperature of the parts a and C of the foil element,

iii) the foil element of the invention obtained in step ii) is, where appropriate, subjected to back injection molding.

The foil element of the present invention is typically a planar foil element.

Step i)

Step i) relates to the manufacture of the foil element of the invention. Step i) is preferably carried out by a process comprising steps ia), ib), ic), id) and ie). The individual process steps ia) to ie) have already been described above.

The meaning of parts A, B, C, D and E is also as described above. In addition to components A, B, C, D and E, the three-dimensionally deformed foil element of the present invention may also contain other layers where appropriate.

Step ii)

The isostatic high-pressure deformation in step ii) is preferably carried out according to the process described in EP-a0371425, wherein a process temperature is selected which is below the softening temperature of the parts a and C of the foil element.

In general, the inventive foil element constructed from the parts A, B, C, D and E obtained in step i) is subjected to the action of a fluid pressure medium at an operating temperature and to an isostatic deformation, said deformation being carried out at an operating temperature below the softening temperature of the material of the carrier foils a and C of the foil element and at a pressure medium pressure of generally > 20bar, preferably > 100bar, particularly preferably 200 and 300 bar. The deformation of the foil is usually effected over a period of a few seconds, preferably over a time interval of < 10 seconds, particularly preferably over a time interval of < 5 seconds. In this regard, 100% to 200% deformation can be achieved without stress whitening of the dry-stir vision.

In a preferred embodiment, the isostatic high-pressure deformation is generally carried out at a temperature of at least 5 ℃, preferably at least 10 ℃, particularly preferably at least 20 ℃ or higher, but below the softening temperature of the part a of the foil element. Particularly preferred as material for the at least partially transparent carrier foil is polycarbonate based on bisphenol A (e.g. 20 Makrofol)Foil) has a softening temperature of about 150 c or higher. Isostatic high-pressure deformation of a foil element with the polycarbonate foil as carrier foil can be carried out at room temperature. Due to other components, especially due to the fact thatThe overprinting of the icon is effected if, as described above, polycarbonate based on bisphenol a is used as the foil material of the carrier foil, the isostatic high-pressure deformation is preferably carried out at an operating temperature of 80-130 ℃. When using carrier foils composed of other materials, the person skilled in the art can easily determine the treatment temperature in step ii), as long as the softening temperature of the material is known.

Suitable devices for carrying out said isostatic high-pressure deformation for producing the three-dimensionally deformed foil elements according to the invention are mentioned, for example, in EP-a 0371425.

The three-dimensionally deformed foil element obtained after step ii) can be brought to the final desired contour by, for example, shearing, stamping or laser action. Suitable methods and devices for bringing the foil element to its final contour, for example by stamping, shearing or laser action, are known to the person skilled in the art. Generally, punching, shearing or laser action is performed with high precision, and one suitable shearing method is, for example, precision cutting.

Step iii)

The aforementioned foil element comprising at least one electroluminescent device already has sufficient stiffness and dimensional stability for many applications.

For some applications, however, it may also be necessary to back-injection mould the already formed deformed foil element to a hardness that meets the requirements for the finished product.

The back-injection is usually performed according to an injection molding process for stamped and preformed foil elements, which is known to the person skilled in the art, in particular under the terms "in-mold decoration" (IMD), "in-mold labeling" (IML) or "in-mold lamination" (FIM).

The foil element of the invention, which is generally planar in form, and the three-dimensionally deformed foil element of the invention, may be used in many applications. Suitable applications are, for example, the use of the foil element according to the invention for forming decorative and cover panels or display elements for land vehicles, ships and aircraft, for forming safety belt panels or warning indicator panels in land vehicles, ships and aircraft, for forming warning indicator panels in buildings, for forming housing elements for mobile electronic instruments, such as mobile telephones or remote controls, and for forming housing elements for stationary electronic instruments, such as printers, copiers, PCs, notebooks, or for forming small or large household appliances, or for forming keyboards.

Claims

1. A foil element consisting of:

b) a semi-transparent reflective layer (B) formed on the substrate,

c) an at least partially transparent foil, i.e. component C,

d) at least one electroluminescent element, component D, applied on the at least partially transparent foil C, comprising the following components:

DA) an at least partially transparent electrode, i.e. the component DA,

DB) optionally a first barrier layer, i.e. the component DB,

DD) an optional further isolating layer, namely the component DD,

DE) back electrode, i.e. the component DE,

e) the protective layer, i.e., component EA, or the foil, i.e., component EB,

wherein the carrier foils A and C have a layer thickness of 50 μm-500. mu.m.

2. Foil element according to claim 1, characterized in that the foil material of the carrier foils a and C is at least one material selected from the group consisting of: polycarbonates, polyesters, polyamides, polyimides, polyarylates, organic thermoplastic cellulose esters, and polyfluorocarbons.

3. A foil element according to claim 1 or 2, characterized in that the carrier foil a and/or foil C is provided with an icon in the form of an opaque or semi-opaque colour stamp.

4. A foil element according to claim 1 or 2, characterized in that the semitransparent reflective layer B has a visible light transmission of 5-60%.

5. A foil element according to claim 2, characterized in that the semi-transparent reflective layer B has a visible light transmission of 10-40%.

6. A foil element according to claim 1 or 2, characterized in that at least one metal selected from the group consisting of: aluminum, magnesium, tin, gold, silver, copper, zinc, nickel, chromium, cobalt, manganese, lead, titanium, iron, and tungsten, or a metal printing ink.

7. A foil element according to claim 1 or 2, characterized in that the at least one light emitting element has a terminal.

8. Foil element according to claim 1 or 2, characterized in that the at least one electroluminescent element is operated under alternating current and the alternating current is generated by an electroluminescent inverter.

9. A foil element according to claim 1 or 2, characterized in that the foil element contains as component F at least one LED element in addition to components A, B, C, D and E.

10. Foil element according to claim 1 or 2, characterized in that the at least partially transparent electrode DA of the electroluminescent element D is a planar electrode consisting of a conductive material selected from the group consisting of an ITO screen printed layer, an ATO screen printed layer, a non-ITO screen printed layer and an intrinsically conductive polymer system.

11. Foil element according to claim 1 or 2, characterized in that the layer DC comprising at least one field-excitable luminescent substance comprises ZnS doped with phosphorus as luminescent substance.

12. Foil element according to claim 1 or 2, characterized in that the back electrode DE of the electroluminescent element D is a planar electrode consisting of an electrically conductive material selected from the group consisting of: metal, carbon, ITO screen printed layer, ATO screen printed layer, non-ITO screen printed layer and an intrinsically conductive polymer system, wherein metal or carbon is added to the conductive material for improving the conductivity and/or layers consisting of these materials are supplemented.

13. Three-dimensionally deformed foil element, producible by an isostatic high-pressure deformation of a foil element according to one of claims 1 to 12 at a processing temperature below the softening temperature of the components a and C of the foil element.

14. Method of manufacturing a foil element according to one of claims 1-12, comprising the steps of:

ia) providing an at least partially transparent carrier foil a and, where appropriate, embossing an icon on said at least partially transparent carrier foil,

ib) applying a semi-transparent reflective layer B on the at least partially transparent carrier foil,

ic) applying an at least partially transparent foil C and if appropriate graphics on said at least partially transparent foil C on said semi-transparent reflective layer,

id) applying at least one electroluminescent element D on said at least partially transparent foil,

ie) applying a protective layer EA or foil EB on the at least one electroluminescent element.

15. Method of manufacturing a three-dimensionally deformed foil element, comprising:

i) a foil element manufactured by the method of claim 14,

ii) subjecting the foil element obtained in step i) to isostatic high-pressure deformation at a treatment temperature below the softening temperature of the parts A and C of the foil element,

iii) optionally back-injection moulding the foil element obtained in step ii).

16. Use of a foil element according to one of claims 1 to 12 or manufactured according to claim 14, or a three-dimensionally deformed foil element according to claim 13 or manufactured according to claim 15, for forming decorative panels or cover panels or display elements for land vehicles, ships and aircraft, for forming safety belt panels or warning indicator panels in land vehicles, ships and aircraft, for forming warning indicator panels in buildings, and for forming housings for mobile or stationary electronic appliances, or for forming small or large household appliances, or for forming keyboards.