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Publication numberUS20020021086 A1
Publication typeApplication
Application numberUS 09/403,701
PCT numberPCT/EP1998/001958
Publication dateFeb 21, 2002
Filing dateApr 3, 1998
Priority dateApr 26, 1997
Also published asDE19717740A1, DE19717740C2, EP0978220A1, EP0978220B1, US6411029, WO1998049871A1
Publication number09403701, 403701, PCT/1998/1958, PCT/EP/1998/001958, PCT/EP/1998/01958, PCT/EP/98/001958, PCT/EP/98/01958, PCT/EP1998/001958, PCT/EP1998/01958, PCT/EP1998001958, PCT/EP199801958, PCT/EP98/001958, PCT/EP98/01958, PCT/EP98001958, PCT/EP9801958, US 2002/0021086 A1, US 2002/021086 A1, US 20020021086 A1, US 20020021086A1, US 2002021086 A1, US 2002021086A1, US-A1-20020021086, US-A1-2002021086, US2002/0021086A1, US2002/021086A1, US20020021086 A1, US20020021086A1, US2002021086 A1, US2002021086A1
InventorsChristian Czak
Original AssigneeChristian Czak
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Plastic shaped body with an integrated optoelectronic luminous element
US 20020021086 A1
Abstract
The invention relates to a plastic shaped body with an integrated optoelectronic luminous element and to a method for the production thereof. To this end, translucent and cold-stretchable plastic film is three-dimensionally formed at least in the area of the luminous elements and subsequently sprayed with thermoplastic synthetic material. The luminous elements are screen printed onto the unshaped film in the form of luminous fields before the plastic film is formed.
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Claims(22)
1. Plastic form body with one or several integrated, opto-electronic active luminous elements is characterized by at least one translucent, cold-stretchable, three-dimensionally, elastic, formed plastic foil (1), which is then back-injected with thermoplastic plastic (3), and which, before the formation of the luminous elements in the screen printing or by means of digital printing processes is applied in the shape of luminous fields (17).
2. Plastic form body, according to claim 1, is characterized by the luminous fields (17), which are electro-luminescence fields that basically consist of two electrically insulated electrodes; one is a base electrode (10;13) and one is a cover electrode (7;14), which is located between an electro-luminescence layer (8).
3. Plastic form body, according to claims 1 or 2, is characterized by the electrodes (10,13; 7,14) and the electro-luminescence layer (8), which is applied in the form of screen printing paste, and has at least one of the dielectric layers or insulation layers (9) located between the electro-luminescence layers (8) and the base electrode (10;13), and this screen printing layer (7-11) is formable at an operating temperature below the heat distortion temperature of plastic foil (1).
4. Plastic form body, according to one of the claims 1 through 3, is characterized by the electro-luminescence coating (8) that consists basically of organic or inorganic substances, which can take the form of a fine powder and/or is micro-encapsulated, and therefore, wide-ranging water vapor sensitive elements with diameters of 10 to 60 μm to which respective plastic formable and dielectric high-quality screen printing colors are added.
5. Plastic form body, according to one of the claims 1 through 3, is characterized by the plastic foil (1) that is back-injected on the inner side and/or outer side with thermoplastic plastics (3).
6. Plastic form body, according to one of the claims I through 4, is characterized by the plastic foil (1) whose graphic design takes the shape of a sandwich on the inner side and/or outer side with an additional thermoplastic foil (12).
7. Plastic form body, according to one of the claims 1 through 6, is characterized by the wide-ranging transparent and electrical conducting cover electrode (7) that consists of so-called Indium-Tin-Oxide (ITO) paste.
8. Plastic form body, according to one of the claims 1 through 7, is characterized by the plastic foil (1) of the cover electrode that has the form of an ITO-sputter layer (14) and/or reflective semi-transparent layers, and these wide-ranging transparent cover electrodes (14) are printed (pressed) in the area of stronger deformation and/or in the area outside the luminous fields (17) by means of an electric conducting polymer paste.
9. Plastic form body, according to one of the claims 1 through 8, is characterized by a metallized, transparent and very thin foil (13) (instead of an insulation layer [9] and the silver paste base electrode [10]) that is laminated on the electro-luminescence coating (8) or, respectively, on the cover layer (11).
10. The process to produce a plastic form body, according to one of the claims 1 through 9, is characterized by the following steps:
Prepare a transparent, cold-stretchable, thin plastic foil substrate;
Deposit a graphic shaping (design) in the form of an opaque (covering) and/or translucent screen print formation;
Deposit a wide-ranging transparent, electric-conducting cover electrode layer;
Deposit an electro-luminescence coating;
Deposit an insulating, dielectric layer;
Deposit an electric-conducting base electrode layer;
Three-dimensional formation of the plastic foil substrate from single or multiple printed panels;
Stamping out the single panel.
11. The process to produce a plastic form body, according to the claims 1 through 9, are characterized by the following steps:
Prepare a transparent cold-stretchable thin plastic foil substrate that covers the entire surface on the inner side with an ITO-layer and/or reflective semi-transparent layers in sputter processes;
Deposit a graphic shaping in the form of an opaque (covering) and/or translucent screen printing formation;
Deposit an electro-luminescence layer;
Deposit an insulating, dielectric layer;
Deposit an electric-conducting base electrode layer;
Three-dimensional formation of plastic foil substrate from single- or multiple printed panels;
Stamping out the single panels.
12. Process, according to claim 10 or 11, is characterized by the formed plastic foil substrate that is placed in the injection molding die and is back-injected with suitable thermoplastic plastic; whereby, the electrical connection surface for the electroluminescence electrodes and, if applicable, the window, stays recessed or the electrical connection surfaces with inserts and/or additional components in the form of electric conducting contact elements and/or foil cables that are led outwardly.
13. Process, according to one of the claims 10 to 12, is characterized by the three-dimensional formation of the plastic foil substrate by means of isostatic high pressure formation with a pressure of the printing (pressure) fluids greater than 20 bar resulting in a warming of the operating temperature below the distortion temperature of plastic.
14. Process, according to one of the claims 10 to 12, is characterized by the three-dimensional plastic formation resulting from the insertion of the plane unformed plastic foil substrate with an injection mold die; whereby, the injection mold die is warmed to an operating temperature lower than the distortion temperature of plastic and the shaping by mainly mechanical shaping and, finally, the end shaping that results from the thermoplastic injection compound or mainly by the thermoplastic injection compound itself.
15. Process, according to one of the claims 10 to 12, is characterized by the plastic foil substrate that is formed three-dimensionally by a mechanical stamping process and so is inserted pre-shaped into an insertion mold die.
16. Process, according to one of the claims 10 to 15, is characterized by an intermediate step on the base electrode layer in which a screen printing layer is applied based on watery polyurethane dispersion and/or polyurethane color containing solvent to optimally bind the thermoplastic plastic compound; whereby, the electrical connecting surfaces for the electro-luminescence electrodes and, if applicable, the window stay recessed.
17. Process, according to one of the claims 10 to 16, is characterized by the screen printing of the electro-luminescence layer that is mixed next to various electroluminescence pigments, as well as daylight luminous (fluorescent) pigments.
18. Process, according to one of the claims 10 to 17, is characterized by “steerable” luminous fields that are nested and separated and can be produced so that the base electrode connection of a inner-lying luminous field can be guided outwardly by silver conducting paste, and thereby, additional local insulating pressure (print) layers are placed on the outwardly lying electrode connections so that these inner-lying base electrode connections can be guided outwardly electrically insulated, and thus, the base electrode connections that are designed in this manner can be triggered electrically separated.
19. Process, according to one of the claims 10 to 18, is characterized by a thin thermoplastic foil laminated on the base electrode layer and so, in cases of back-injection by means of thermoplastic plastics, a higher temperature load and especially inconvenient injection positions with correspondingly high temperatures can be utilized.
20. Process, according to one of the claims 10 through 19, is characterized by the injection with thermoplastic plastics that can take place not only on the inner side, but also on the outer sides or, respectively, also from both sides, so that optical lens effects and lighting cable effects can be achieved; especially thermoplastic plastics based on polycarbonate (PC) and polymethylmethacrylate (PMMA) as well as transparent acrylonitrile-butadiene-styrene (ABS), polyamide (PA) and polypropylene (PP) plastics, as well as respective mixtures of the mentioned plastics, can be used.
21. Process, according to one of the claims 10 to 20, is characterized by, that instead of the deposit of an insulating dielectrical layer and the base electrode layer by means of a base paste, only the geometry for the purpose of strengthening the ITO-electrode and its electrical connection is pressed (printed), and finally, with or, respectively, without watery polyurethane dispersion coating, a metallized transparent thin foil is laminated on the backside, which produces the dielectric and the base electrode, including reflector.
22. Process, according to one of the claims 10 to 21, is characterized by the monitoring and operation control of the ITO-screen printing coating's positioning since it is, to a large extent transparent and, therefore, difficult to identify and its positioning to the silver paste printing (pressing) results from electrical contact pins that the predetermined test geometry comes into contact with the geometrically exact electrical measuring adapter and that only a positive signal is given whenever the nearly transparent, but electrical conducting ITO-screen printing geometry is brought within predetermined tolerances so then the surface resistance of the ITO- and silver pastes test geometry is determined and these measured values are used for process- and operations control so that, additionally, by means of correspondingly sized electrical testing pins on a suitable test geometry, the puncture strength of the insulation pressure (print) and the electro-luminescence pressure (print) is monitored and recorded; whereby, the drying state of the layer construction is controlled and the electrical capacity value of the test geometry is measured and evaluated against the predetermined tolerances, and this process is made with certain requirements of the surroundings, such as controlled humidity and temperature.
Description
  • [0001]
    The present invention is a plastic form body with graphically designed surfaces and integrated electro-luminescence elements (EL elements). For example, graphic and electro-luminescence structures are placed on transparent and cold-stretchable thermoplastic plastic foil by means of silk screen printing (serigraphy), then subjected to a pushing isostatic high-pressure deformation, stamped and placed in an injection mold and back-injected generally on the inner wall by means of suitable thermoplastic plastic resulting in a three-dimensional plastic form component with integrated EL luminous fields.
  • [0002]
    The DE 44 30 907 A1 makes a three-dimensional electro-luminescence indicator based on an electro-luminescence lights integrated in a three-dimensional formed body. The preformed electro-luminescence lights are formed in a whole piece on a substrate. The disadvantage with this is the separate design of the aforementioned light transmitting layer and the electro-luminescence light and their exact positioning to each other that results in an expensive and costly production process.
  • [0003]
    A similar three-dimensional electro-luminescence indicator is made known with WO-A-94/14180. Here also, prefabricated, foil formed electro-luminescence lights are applied on carrier material and can be formed together. This has the disadvantage that a separate design of the light transmitting layer of the carrier material and the electro-luminescence light and an exact positioning of the EL-lights in the carrier material is necessary, which makes the production expensive and cost-intensive.
  • [0004]
    Usually the decorative foils are formed after the vacuum process or the compressed air process to a three-dimensional deep-drawing formed body. Then the graphically designed thermoplastic foils are heated to a temperature above the material's heat distortion temperature so that they can be shaped with relatively little pressure (such as vacuum). These vacuum- and compressed air processes can be used very efficiently with graphically non-critical or neutrally designed foils and form bodies, and function with vacuum processes at a medium pressure of less than 0.95 bar and with compressed air processes at an operating medium pressure of less than 6 bar.
  • [0005]
    Form components that require exact positioning of graphically designed elements and a very precise image with patterns and/or a great contour sharpness, and which must have a precise form after the deep-drawing process, the procedures of the isostatic high pressure forming according to DE 38 40 542 C1 (also in a somewhat limited way, the so-called hydro-forming) offer advantages.
  • [0006]
    The production of these types of electro-luminescence fields in connection with the graphic design, must take the very precise positioning of the individual presses and processes together into consideration. The positioning of the nearly transparent ITO-paste graphics, especially, presents a fundamental criterion of quality. U.S. Pat. No. 5,583,394 makes a procedure of recording known that provides invisible positioning markers in a visible light, which, by means of a corresponding light source, are identified with an ultra-violet light for respective reading sensors and, thus, make an exact positioning possible. The disadvantage is that these registration marks can only be applied with additional operating steps and used only with special light sources and special positioning sensors.
  • [0007]
    Electro-luminescence screen printing pastes are generally made up of inorganic substances and, here again, are very pure ZnS, CdS, ZnxCd1-xS, etc. Compounds of the II and VI group of the periodic system are of importance that generally are doped or activated with Cu, Mn, Ag, etc. Normal colors are yellow, green, green-blue, blue-green and white.
  • [0008]
    Respective to the state of technology, these types of luminescence pigments can be microencapsulated with diameters of typically 15 to 60 μm in order to be added to various silk screen printing inks (colors), or non-encapsulated, certainly taking the special hygroscopic characteristics of the ZnS pigments into consideration. Fixing agents are used that, on the one hand, provide good adhesion for the so-called ITO-layers, continue to insulate well, reinforce the dielectric, in order to improve the puncture or disruptive strength with high electrical field strengths and, additionally, have a good water vapor block and so additionally protect the phosphorous pigments to lengthen their life expectancy.
  • [0009]
    Generally, phosphorous pastes of these types are put on by screen printing or other coating procedures, such as brushing, rolling, coil coating, etc. on transparent plastic foils or glass, which again have a wide transparent electric conducting layer and with it the electrodes for the visual side. Finally, the dielectric and the back-side electrode are produced by printing (press) techniques and/or laminating techniques.
  • [0010]
    The usual ITO-paste layers (or also tin oxide coatings, etc.) applied by screen printing, however, have the advantage of extensive random geometrical design possibilities, but the vapor-deposited or sputter-deposited transparent and electrical-conducting layers still have the disadvantage of having less optical transparency or translucency and, furthermore, have a much lesser degree of conducting capacity, of at the most some 100 Ohm per square in comparison to some less than 10 Ohm per square with ITO-polyester foil or some less Ohm per square with ITO-coated glass. But the glass can have pastes added (for example, In2O3/SnO2), which must, however, be fired at over 500 C. and, therefore, can already deliver with a 0.25 μm film strength, an optical transparency of greater than 95% and a conducting capacity of a single layer is from 500 to 1000 Ohm per square.
  • [0011]
    The purpose of the present invention is to produce a three-dimensional graphically designed plastic form body with integrated electro-luminescence elements economically, with a longer life expectancy, increased luminous intensity and guaranteed performance regardless of the existing electric power supply.
  • [0012]
    In the framework of the present invention it has been determined that the new types of electro-luminescence screen printing inks (colors), new types of ITO (Indium-Tin-Oxide) colors, and new types of insulation and dielectric colors, together with the printing format can be applied, and then the high-pressure formation and the back-injection can be completed by means of thermoplastic plastics by following several ground rules without impairment to the function of the electro-luminescence elements.
  • [0013]
    According to the invention, the previously discussed procedure of the isostatic high-pressure formation is sufficient for forming the plastic components. So-called cold-stretchable plastic foils are provided with printing ink (colors) that, together with an operating temperature below the distortion temperature of the thermoplastic foil's plastic, completes a push-type forming operation to a three-dimensional plastic form component with greater image precision.
  • [0014]
    Advantageously, isostatic high-pressure forming, especially the push-type stamping of the plastic components with preferably several 100 bar compress air (typically 50 to 300 bar), very short cycle times with outstanding controlled and even formation, which results in greater image accuracy and, furthermore, produces the same types of formed components with less heat (which means the time-consuming cool-down phase is discontinued), outstanding dimensionally stable formed bodies and constant contours (which remain the same), which is really essential for the final stamping process and the insertion into the injection molding die, increasing the quality.
  • [0015]
    Other processes for forming the plastic foil three-dimensionally are also possible (for example, mechanical shaping or mechanical stamping methods). A re-forming of the plastic foil placed in an injection molding die can itself result from the injection of the thermoplastic plastic material.
  • [0016]
    The present invention is also based on the cognition that for a product of this type, known screen printing pastes with phosphorous pigments, especially in the microencapsulated form (but also in the non-encapsulated form) based on respective doped compounds of the II and VI groups of the periodic system, especially in forms with Cu, Mn, Ag, etc., doped ZnS pigments in combination with special cold-formable polycarbonate substrate or the various mixtures of polycarbonate and polyethyleneterephthalate (PETP) or polyalkyleneterephthalates are very suitable. Mixtures of additional luminous colors, especially those that, through the electroluminescence radiation for light excitation and release of respective radiation with wide ranges of discretionary spectrals (as narrow banded wave-length peaks) work very positively and effectively.
  • [0017]
    In another development of this procedure, the color printing can be imbedded sandwich-like between two layers of foil material. This results in less problems with the back-injection of thermoplastic plastics, which in this case of color printing, are better protected by the additional foil against distortion and melting in the injection area.
  • [0018]
    In another typical embodiment, a layout of a luminous field has not only two electrical connections, but many fields; for example, with various color luminous fields, such as lettering and/or symbols.
  • [0019]
    In relation to the necessary position exactness, the individual printings have been established within the framework of the present invention; that the registration of the various layers and processes can be realized manually in general by means of registering marks in visible luminous areas (and also automatically), and that each layer based on the nearly transparent ITO-paste can be controlled and registered very well concerning the preciseness of the position and the constancy of the process by means of electrical test configurations in connection with conducting paste structures. Additionally, the allowable surface resistance and/or contact or transition resistance of the ITO-paste contacts to the conductor will be evaluated and recorded.
  • [0020]
    The invention at hand will be explained more closely by several embodiments and should, thereby, emphasize the invention-related characteristics:
  • [0021]
    Shown:
  • [0022]
    [0022]FIG. 1: a section through a typical three-dimensional plastic form body with EL-luminous fields;
  • [0023]
    [0023]FIG. 2: an enlarged detailed section of FIG. 1;
  • [0024]
    [0024]FIG. 3: a section through another typical three-dimensional plastic form body with EL-luminous fields;
  • [0025]
    [0025]FIG. 4: an enlarged detailed section from FIG. 3;
  • [0026]
    [0026]FIG. 5: a section through another embodiment of a three-dimensional plastic form body with EL-luminous fields;
  • [0027]
    [0027]FIG. 6: a section through another embodiment of a three-dimensional plastic form body with EL-luminous fields;
  • [0028]
    [0028]FIG. 7: a section through another embodiment of a three-dimensional plastic form body with EL-luminous fields;
  • [0029]
    [0029]FIG. 8: a section through a modified embodiment of a three-dimensional plastic form body with EL-luminous fields;
  • [0030]
    [0030]FIG. 9: a section through a three-dimensional plastic form body with EL-luminous fields, but in this case, the injection occurred from the outside; that is the three-dimensional decorative foil component is applied to the core of the injection mold;
  • [0031]
    [0031]FIG. 10: an overview of a test geometry to check the preciseness of the positions of the various pressure (printing) geometries and especially the electrical conducting and nearly transparent (and therefore difficult to identify) ITO-screen printing geometry;
  • [0032]
    [0032]FIG. 11: a section through the system according to FIG. 10;
  • [0033]
    [0033]FIG. 12: an overview of the three-dimensionally designed plastic form body with graphically designed surface and electro-luminescence luminous fields.
  • [0034]
    According to FIG. 1, a typically 100 to 300 μm thick and transparent foil (1), made preferably of polycarbonate, such as polycarbonate-polyester mixture, with specification-determined surfaces (as, for example, high gloss finish or satin matte finish) provided on the inner side with graphic print (press) (2), preferably the screen printing process and the respective screen printing inks are sufficient for application. However, a combination of other printing processes (for example, offset-printing for graphic designs) can be used. Digital printing processes especially (such as, for example, ink jet processes) are fundamentally suitable. In this graphic printing (2), luminous fields (17) are imbedded, which, likewise (for example, in screen printing process) can be applied to the inner side of the foil (1). In the next step the printed decorative foil (1) is subjected to a push-type isostatic high-pressure forming in order to attain its pre-determined three-dimensional shape. Finally, the formed foil (1) with thermoplastic plastic (3) is back-injected. The contact of the electro-luminescence fields (17) follows from a released contact surface (6).
  • [0035]
    [0035]FIG. 2 shows an enlarged detailed section of the decorative foil-injection mold body according to FIG. 1. In the presented case, the first printing step of the graphic design (2) with opaque (covering) and transparent or translucent colors is completed (that is, applied to the foil material [1]). Finally an extensive transparent cover electrode (7) (for example, in the form of an ITO-screen printing paste) and the desired structure are applied. On this ITO-layer (7), the electro-luminescence pastes (8) are pressed in predetermined structures; whereby, not only an electro-luminescence paste (8) can be used with an electro-luminescence color, but also with many different radiating EL-colors. The EL-colors can especially be mixed with daylight luminous (fluorescent) colors in order to achieve the desired color effect when activating the EL-fields (17). Furthermore, these EL-elements (7) can be used with various circuitry wiring systems, especially with the separate design of the silver conducting paste electrodes (7). Finally on the EL-paste printing (7), insulation printing colors (9) are usually achieved in two printing processes with varying screens to prevent marks or defects and to produce the so-called dielectric.
  • [0036]
    Usually these insulation pastes (9) are white in color and, therefore, have a reflection effect for the EL-radiation.
  • [0037]
    In connection to these insulation layers (9), a silver conducting paste structure (10) is pressed on, thus producing the base electrodes.
  • [0038]
    Normally the surrounding ITO-paste pressing is simultaneously reinforced in what is generally described as the “Bus-bar” technique, so that an even and constant electrical field strength can be attained over the total EL-luminous field (17). Furthermore, the printing of the silver paste (10) also strengthens the connecting surfaces of the ITO-electrodes (7), but these reinforcements are understood in the sense of the reduction of electrical surface's resistance.
  • [0039]
    Frequently it is advantageous to cover these various screen-printing layers (7-10) additionally with a polyurethane dispersion coating (11) in order to subsequently maintain an optimal connection of the various thermoplastic injection mold compounds. These cold-stretchable and graphically designed EL-decorative foils (1) are usually subjected to multiple uses of a push-type isostatic high-pressure forming and for this purpose, are typically warmed from 40 C. to 80 C. This warming is, however, certainly below the heat distortion temperature of thermoplastic plastics of the decorative foil (1), because otherwise there would not be such a high degree of image accuracy of the deep-drawn printed picture.
  • [0040]
    In connection to the deep-drawing process, there is an exact contour stamping of this three-dimensional object and it is then placed in an injection mold die, and in the presented case is back-injected by means of a suitable thermoplastic plastic (3) mentioned in the beginning. Therefore, the selection of the injection site on the form must be made very carefully and the graphic design must be taken into consideration in order to prevent distortions, deviations and re-melted spots.
  • [0041]
    Generally the connecting places for the EL-luminous fields (17) are already kept free in the injection mold die, so that the contacts of the EL-electrode connections (6) take place by means of spring finger contact, crimping or electrical conducting tape. Often the silver conducting paste connecting surfaces are still additionally subjected to by passive, electrical conducting layers in relation to the screen printing processes and so attains increased protection again oxidation, resulting in a longer life expectancy of these connections.
  • [0042]
    In another development of this embodiment, electrical connecting elements can also be crimped or cramped in the three-dimensionally formed decorative foils and this unit can be placed together or also behind each other in the injection mold die and be back-injected; therefore, attaining extreme mechanical, as well as electrical, load-bearing connection elements for the EL-luminous fields.
  • [0043]
    [0043]FIG. 3 shows, that in addition to the previous embodiment, a thermoplastic plastic foil (12) can be laminated on the underside of the graphically designed EL-decorative foil (1).
  • [0044]
    The adhesive bond can, depending on the required specifications, achieve a thermoplastic hot-melt screen printing coating by the screen printing technique of a polyurethane dispersion coating; that the additional thermoplastic foil (12) can be applied by a high melting process to bond with the graphically designed EL-decorative foil (1) or this thermoplastic foil (12) can have a corresponding additional coating (for example, a corresponding hot melt coating) and can by a lamination process attain a sandwich-type bonding foil.
  • [0045]
    The advantage of this additional foil on the inner side is that the graphic and color design of the decorative foil (1) has greater protection on the injection side of the injection mold die and permits, especially the realization of critical geometries that often have inconvenient choices of injection positions, which would result in high injection temperature defects and color distortions in the injection sites, which can be extensively prevented by this additional foil.
  • [0046]
    [0046]FIG. 4 shows an enlarged section through the embodiment, according to FIG. 3. The sequence of the applied layers correspond basically to FIG. 2. However, an additional thermoplastic plastic foil layer (12) is applied over the described layer succession (7-11).
  • [0047]
    According to FIG. 5, instead of the insulation layer (9) and the back electrode layer (10), a metallized plastic foil (13) is laminated on by means of screen printing. The adhesive bond can, depending on the required specifications, by screen printing technique of a polyurethane dispersion coating (11), attain a thermoplastic hot melt screen printing coating, the additional metallized foil (13) can be applied by a high melting process to bond with the graphically designed EL-decorative foil (1) or this metallized foil (13) has a corresponding additional coating (for example, a respective hot melt coating) and can by a lamination process result in a sandwich-type bonding foil. The advantage of this embodiment lies in the smaller amount of printings (pressings), in the higher quality of the insulation layer and the bonded good formability. The fundamental disadvantage of this embodiment lies in the limited potential to trigger the EL-luminous fields (17). Generally in this case only a common “steerable” EL-luminous element (17) is formable and, furthermore, this type of embodiment shows no cost-effective solution with regard to energy supply, since the total surfaces work extensively and not only individual selective surfaces. This disadvantage could in this respect be used in another embodiment since the usual dielectric layers (9) with the second screen printing process have barely more than 20 to 30 μm thickness and metallized plastic foils must be laminated on with this thickness in order to achieve the same kind of electrical supply some 106 volt/cm on an electric field strength for the purpose of EL-excitation. This special embodiment is only typically 50 μm thick and back-sided metallized plastic foil (13) is used; the three-dimensional design is selected so that only in the areas of desired EL-excitation, a stretching of the materials (for example, around 100%) occurs and, through which, this as dielectric functioning layer, is reduced by half and so with a normal EL-distribution voltage builds up a sufficiently high electric field so that EL-excitation can take place in these selective areas.
  • [0048]
    [0048]FIG. 6 shows instead of the ITO-paste coating (7) of the decorative foil (1) by means of screen printing, a transparent decorative foil with ITO-sputter coating (14) and/or reflective semi-transparent layers. This embodiment has the fundamental advantage that this type ITO-coated transparent foil (14) has a very high optical transparency, typically in areas greater than 85% up to 95% and, additionally, offers very small surface resistance values, typically in the area of 100 to 1000 Ohm per square. In this way the EL-luminous element (17) can achieve a higher optical luminous intensity with also correspondingly less size.
  • [0049]
    The disadvantage, however, beside the high price for this type of coated plastic foil (14), is the complete flatness of the electrical conducting layer and the small level of formability.
  • [0050]
    The problem with regard to the limited formability without electrical interruption can, to this extent, be solved as the usual EL-fields (17) in any case usually don't have strong three-dimensional forms and in the cases of strong formations, the electrical conducting capacity's so-called “Bus-bars” (that are in general silver paste structures) are used. These electric conducting polymer pastes are, however, relatively good plastic and formable and can produce a protected contact for this transparent cover electrodes. Moreover, no additional printings (pressings) are necessary because by corresponding designs of the insulation structures of these ITO-structures, reinforced conducting paste structures can simultaneously occur with the base electrode pressing (printing).
  • [0051]
    According to FIG. 7, instead of the ITO-paste coating (7), the decorative foil (1) by means of the screen printing, a transparent decorative foil (1) is used with the ITO-sputter coating (14) and/or reflective semi-transparent layers and, additionally, as with the previous embodiment, a thermoplastic plastic foil (12) is laminated on the underside of the graphically designed EL-decorative foil.
  • [0052]
    In FIG. 8, instead of the ITO-paste coating (7), the decorative foil (1) by means of screen printing a transparent decorative foil (1) is used with ITO-sputter coating (14) and/or reflective semi-transparent layers and instead of two-stage insulation printing (pressing) (9) and its silver paste printing (pressing) (10), a metallized thermoplastic plastic foil (13) is laminated on the underside of the graphically designed EL-decorative foil (1).
  • [0053]
    [0053]FIG. 9 shows the injection of the decorative foil (1) with thermoplastic plastic (3) can also take place from the outside; that is, the three-dimensional decorative foil component (1) is applied on the injection mold die core. For this, the sprayed-on thermoplastic plastic (3) has corresponding notches (16) in the area of EL-luminous (17) in order to allow the light to emit out or at least in the area of the EL-luminous surfaces (17) to be formed transparent or translucent.
  • [0054]
    [0054]FIG. 10 is an overview of a test geometry to check the position preciseness of the various pressure geometries and, especially the electric-conducting and the nearly transparent and therefore, difficult-to-identify ITO-screen printing geometry. On a carrier substrate [for example, a foil (1)] according to the previously described process method, an electro-luminescence element is pressed on. On the basis of a typical embodiment there are four connection surfaces (18) (for example, made of silver conducting paste); whereby, two surfaces are each for the ITO-structure (19) and two surfaces are each for the silver, such as conducting paste structure (20). The connection surfaces (18) of the ITO-paste structure (19) are reinforced with silver paste so that a point contact finger (21) can reach a secured electrical contact, which, additionally, is relatively non-critical from the standpoint of its position. By special selection of the geometry, almost every determined tolerance of the diverse press structures is checked very easily by this electrical test adapter and recorded. So, the various structures must simply be formed respective to the checked tolerances (for example, always be printed (pressed) with 0.1 mm or also 0.2 mm projection). Should, however, an error in the positioning in the individual press process take place, the application of the respective stress test will reveal the amounts of resistance and these can very easily be coordinated to the particular errors. Furthermore, these electrical test geometries can also check the insulation printing (pressure) (22) and the EL-printing (pressure) (23) as to their positioning preciseness, and additionally, can also conduct insulation tests and surface resistance tests. Moreover, on the basis of these test geometries, certain selected EL-potential (stress) and optically the luminous field (24) can also be checked. Furthermore, this EL-luminous field (24) can also be checked with fully automatic color measuring sensors, such as intensity measuring sensors, for required specification values.
  • [0055]
    [0055]FIG. 11 shows a section of the system, according to FIG. 10, again.
  • [0056]
    FIGS. 12 show examples of three-dimensional surface forms with built-in electro-luminescence elements, in which EL-elements for dial illumination, functional indicators or others are placed.
  • Drawing Legend
  • [0057]
    [0057]1. Plastic foil (decorative foil)
  • [0058]
    [0058]2. Printed (pressed) coating (for graphic design and EL-structure)
  • [0059]
    [0059]3. Back-injection (thermoplastic plastic)
  • [0060]
    [0060]4. EL-light emission range (without back-injected plastic)
  • [0061]
    [0061]5. EL-light emission range (with back-injected plastic)
  • [0062]
    [0062]6. Bonding of the diverse EL-electrodes
  • [0063]
    [0063]7. ITO-paste printing (pressing)
  • [0064]
    [0064]8. El-paste print (including various daylight luminous color mixtures)
  • [0065]
    [0065]9. Insulation printing (pressing) (=dielectric, insulator)
  • [0066]
    [0066]10. Silver paste print (press)
  • [0067]
    [0067]11. Polyurethane dispersion coating
  • [0068]
    [0068]12. Thermoplastic plastic foil
  • [0069]
    [0069]13. Metallized thermoplastic plastic foil
  • [0070]
    [0070]14. ITO-sputter layer
  • [0071]
    [0071]15. EL-light emission range (with front-sided plastic injection)
  • [0072]
    [0072]16. Notch
  • [0073]
    [0073]17. Luminous fields
  • [0074]
    [0074]18. Connection surface
  • [0075]
    [0075]19. ITO-structure
  • [0076]
    [0076]20. Conducting paste structure
  • [0077]
    [0077]21. Contact finger
  • [0078]
    [0078]22. Insulation printing (pressing)
  • [0079]
    [0079]23. Electro-luminescence print
  • [0080]
    [0080]24. Luminous field
  • [0081]
    *ITO=Indium-Tin-Oxide
  • [0082]
    *EL=Electro-luminescence
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US6936783Jun 26, 2003Aug 30, 2005Shin-Etsu Polymer Co., Ltd.Push-button switch member and manufacturing method of same
US6984799Feb 17, 2004Jan 10, 2006Shin-Etsu Polymer Co., Ltd.Push-button switch member and manufacturing method of same
US7144540Mar 14, 2003Dec 5, 2006Bayer AktiengesellschaftMethod of making metallized plastic moldings and their use
US7981342Jan 12, 2009Jul 19, 2011International Automotive Components Group North America, Inc.In-mold lamination of decorative products
US8071000Mar 2, 2010Dec 6, 2011International Automotive Components Group North America, Inc.In mold lamination of decorative products
US8083979Sep 21, 2009Dec 27, 2011International Automotive Components Group North America, Inc.In mold lamination of decorative products
US8092733Sep 21, 2009Jan 10, 2012International Automotive Components Group North America, Inc.In mold lamination of decorative products
US20030178739 *Mar 14, 2003Sep 25, 2003Georgios TziovarasMethod of making metallized plastic moldings and their use
US20090174121 *Jan 12, 2009Jul 9, 2009International Automotive Components Group North America, Inc.In-Mold Lamination Of Decorative Products
US20100075140 *Mar 25, 2010International Automotive Components Group North America, Inc.In mold lamination of decorative products
US20100080970 *Apr 1, 2010International Automotive Components Group North America, Inc.In mold lamination of decorative products
US20100154986 *Mar 2, 2010Jun 24, 2010International Automotive Components Group North America, Inc.In Mold Lamination Of Decorative Products
US20100167026 *Jan 17, 2008Jul 1, 2010Hayes Marc ADecorative products having depth of image
Classifications
U.S. Classification313/503, 445/24
International ClassificationB29C51/10, H05B33/02, H05B33/12, H05B33/10, B29C45/14
Cooperative ClassificationB29C2045/14737, B29C45/1418, H05B33/12, B29C2791/007, B29C51/10, B29L2031/747, H05B33/10, B29K2995/0036, B29C2045/14237, B29C45/14811
European ClassificationH05B33/12, B29C51/10, H05B33/10, B29C45/14Q4, B29C45/14D
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