Patent EP-2269795-A1 (EP)
Inventor: THIELCKE BJOERN
IPC: B29C43/20
Filed: 2010-06-01
Abstract: The method comprises introducing an uncured, transparent casting compound into a compression mold with an impression that forms a shaping of a surface curvature of the compression mold, introducing a counterpunch that penetrates partially into the impression of the compression mold so that the casting compound is distributed in a gap between the shaping of the surface curvature of the compression mold and a surface of the counterpunch and fills the gap, and introducing energy into the casting compound. The method comprises introducing an uncured, transparent casting compound into a compression mold with an impression that forms a shaping of a surface curvature of the compression mold, introducing a counterpunch that penetrates partially into the impression of the compression mold so that the casting compound is distributed in a gap between the shaping of the surface curvature of the compression mold and a surface of the counterpunch and fills the gap, and introducing energy into the casting compound so that the casting compound cures to form a self-supporting, flexible, transparent surface layer (4) with a surface curvature on the front side and an impression on the rear side. The energy is introduced in the form of UV radiation, and the counterpunch or the compression mold is permeable to the irradiated UV radiation, which is introduced into the casting compound through the counterpunch or the compression mold. The compression mold has deeper impressions along with the shaping of the surface curvature, where the impressions are likewise filled by the casting compound and form a three-dimensional surface structure in the coating structure. The transparent film (2) is: placed between the counterpunch and the casting compound and joined to the transparent surface layer after the curing of the casting compound; and placed into the impression on the rear side and joined to the surface layer with a material bond using a UV adhesive. The transparent film has a three-dimensional form before placement, and is provided with a surface decoration on a front side facing the surface layer or the rear side. The surface decoration is applied in a printing process before and/or after formation of the surface layer. A support of transparent elastic silicone material or a transparent hard material with cutouts in the region of a switch is placed into the impression on the rear side and joined to the surface layer indirectly with a material bond. The support is either already prefabricated in its three-dimensional shaping, and optionally has a surface decoration on a surface facing the surface layer, or the support is shaped directly in the impression on the rear side. The support, which has actuating plungers on a rear side facing away from the surface layer, is placed with the surface layer fastened on the upper side and with a film lying in between snap domes and contact pills to form a switch, and is indirectly joined to a printed circuit board, where the actuating plungers are movable by way of a membrane (6). Light guides, light shielding elements and/or backlighting are provided in a region of the printed circuit board and in a region of the support using LEDs, a light guiding film or an electroluminescent film. A surface decoration and decorative inserts (10) are provided on and in an outer surface of the surface structure, where the inserts are placed in the compression mold. An inner surface of the compression mold is formed such that it does not allow the casting compound to stick in its cured form or the compression mold has guiding elements for guiding the counterpunch during insertion of the counterpunch into a cavity of the compression mold. An independent claim is included for a flexible, three-dimensional coating structure of a transparent cured casting compound.