Patent FR-2780915-A1 (FR)
Title: Security labels, for e.g. bank notes and electronic products, are made by base deposition on a film, label shape definition, bordered printing window formation, window printing with a passivation coating and window development
Inventor: BREGER ALAIN CHARLES MARCEL JA
IPC: B41M3/14
Filed: 1999-07-09
Abstract: Security labels are produced by base deposition on a film (100), then in defining a label shape (101). The next step is producing (102) a printed window  by photogravure with cells bordered by a stripe forming the window outline. The printing window is printed (103) on the base deposit with a passivation coating, and the window is developed (104) by physicochemical operation. Security labels are manufactured by base deposition on a film (100), definition (101) of the label shape, formation (102) of a printing window on a printing mold having an etch pitted surface of the required geometry and lettering bordered by a stripe forming the window contour, printing (103) of the printing window on the base deposit with a passivation coating, physical-chemical development of the window and removal of the label for direct use or for transfer to the surface and/or the core of a material for security and authentication. Independent claims are also included for the following: (i) an apparatus for carrying out the above process, comprising a feed station for supplying a web (BA1) having a reference system coating, a photogravure printing station for applying photogravure windows on the web, an electrolysis station, a rinsing station, a drying station, an examination station and a winding station; and (ii) a product produced by the above process or the above apparatus and comprising a film with layers of insulating and metallic materials which can be used in the printing of fiduciary matter. Preferred Features: The photogravure cylinder is etched with an image including etched zones, the contours of which form a stripe to allow high resolution printing without indentations. The base deposit is a metal deposit comprising holograms with optically variable diffractive images and designs. The window is developed by electrochemical removal of material around the window. The passivation coating consists of cellulosic, metallic, plastic and/or vacuum metallized plastic material or any other security fillers in the form of wires, patches, stripes, adhesive labels or detachable films. The stripe is 2-50 (especially 20)  mu  thick and is spaced by 2-50 (especially 20) mu  from the etch pits. The aqueous solution used for developing the window is a solution containing 5-150 (especially 100) g/l salt associated with its base or acid, e.g. NaOH and NaCl, or electrolyte containing 5-150 (especially 100) g/l salt associated with its base or acid, e.g. NaOH, NaCl and CuCl2 or CuCl2 and HCl. The electrolyte is used at 5-80 (especially 40) deg C and 2-21 (especially 6) V d.c. and the electrode is an insoluble (e.g. titanium) bar of triangular cross-section with one of its corners directed towards a pre-printed metallized or metallic film for rapid corrosion of the non-printed zones. The apparatus includes a treatment zone with soluble (e.g. copper) electrodes immersed in a current-free electrolyte for rapid deposition (e.g. of copper) on a film pre-printed with windows. The product is used (a) for forming holograms and optically variable diffractive images, the passivation coating being 0.5-8 (especially 1)  mu  thick to allow filling of irregularities of a support onto which the patterns are transferred; (b) for forming a film with insulating and metallic layers used for printing materials for the electronics industry; or (c) in the electronics industry, the layers being 0.05-5 (especially 1)  mu  or 5-600 (especially 50) Angstrom thick. The product may be a polymer film having a hologram, metal, DOVID (diffractive optically variable identification) or other covering and being in the form of cut wires or transfer stripes or patches for application to paper, in the form of cut shapes for cold adhesion to a label or overlay or in the form of peelable film in which the images are destroyed on peeling from a support. Alternatively, the product may consist of an uncoated plastic.