RU2113357C1 - Method of production of relief-phase holographic protective mark - Google Patents

Abstract

FIELD: holography. SUBSTANCE: electronic hologram is exposed onto a layer of electronic photoresist located on a precoat made of material that is opaque to optical radiation, and then it is developed. After development a layer of optical photoresist is applied onto the obtained relief of electronic hologram, analog hologram is exposed onto sections of optical photoresist that do not overlap the relief of electronic hologram, then an additional illumination of the layer of optical photoresist is accomplished with an exposure known to be longer than it is necessary for exposure of analog hologram, and is developed again. Prior to application of the layer of optical photoresist, the obtained relief of electronic hologram is transferred to the precoat, and additional illumination of the layer of optical photoresist is accomplished on the side of the precoat, or prior to application of the layer of optical photoresist, the obtained relief of electronic hologram is hardened through mask and additionally developed; additional illumination of the layer of optical photoresist is accomplished through the same mask. EFFECT: enhanced protection of documents. 3 cl, 2 dwg

Description

 The invention relates to printing and can be used in the manufacture of printed products, such as banknotes, checks, credit cards, identification documents and other securities, in order to protect against counterfeiting.

 Currently, methods are widely used to protect valuable documents from counterfeiting by applying protective labels on them in the form of holographic images. Moreover, depending on the method used to create the hologram, the protective properties of the resulting image are different.

 There is a method of creating protection of a holographic mark, which consists in the fact that an analog hologram is exposed to a plate from an optical photoresist and then developed [1].

 The known method allows to obtain a volumetric image with a simple method, however, it does not have a sufficiently high security from reproduction of a protective image.

 There is also known a method of protective holographic labels, selected as a prototype, comprising exposing the hologram to a plate of electronic photoresist placed on a sublayer of material opaque to optical radiation [2].

 This method provides complete reproducibility and high resistance to unauthorized reproduction of the protective image, as well as high process control.

 However, this method is practically not feasible for volumetric objects, which is one of the attractive features of volumetric holograms.

 The technical task of the invention is the development of a method for creating a relief-phase holographic security mark, combining the advantages of analog and electronic methods for producing a hologram, and thereby allowing the creation of security labels with external attractiveness and providing increased security for the documents for which they are used.

 The problem is solved in a method for obtaining a relief-phase holographic security mark, which consists in the fact that an electronic hologram is exposed to a layer of an electronic photoresist placed on a sublayer made of a material opaque to optical radiation and then developed, in which, according to the invention, after developing on the obtained relief of the electronic hologram is applied with a layer of optical photoresist, an analog hologram is exposed in the areas of the optical photoresist that do not overlap the relief of the electro hydrochloric hologram then performed an additional illumination optical photoresist layer with exposure clearly greater than necessary to expose the hologram, Analog, and again manifest. In this case, before applying the optical photoresist layer, the obtained hologram relief is transferred to the sublayer, and additional illumination of the optical photoresist layer is carried out from the sublayer, or before applying the optical photoresist layer, the obtained hologram relief is blown through the mask and additionally developed, and additional illumination of the optical photoresist layer is performed through the same mask.

 Application of an optical photoresist layer onto the obtained hologram relief, exposure of an analog hologram on it in areas that do not overlap the electronic hologram relief, followed by additional illumination of the optical photoresist layer with an exposure known to be larger than necessary for exposing the analog hologram, and repeated development allow creating protective tags with two types of holograms - electronic and analog - and thereby combine their advantages: increase the security of the tag by applying additional protective elements, inscriptions, lenses, etc. that gives an electronic method; ensure the attractiveness of the label by obtaining a three-dimensional image, which allows the analog method.

 Transferring the relief of the electronic hologram to the sublayer during additional illumination of the optical photoresist layer from the side of the sublayer provides high accuracy of separation of sections of the analog and electronic holograms and the translucency effect of the electronic hologram.

 Doubling the relief of the electronic hologram through the mask with the subsequent development and exposure of the optical photoresist layer through the same mask makes it possible to reduce the height difference between the analog and electronic parts of the hologram and thereby improve the manufacturability of the mark on the protected document.

 In FIG. 1 and 2 are drawings of security labels illustrating a method for creating a relief-phase holographic security label.

 A method of obtaining a relief phase holographic security label is implemented as follows.

 On the layer 1 of an electronic photoresist, for example, FP-617, replaced by a sublayer 2 made of a material opaque to optical radiation, for example, chromium, an electronic hologram is exposed using one of the known methods, for example, by electronic lithography on a ZBA-21 apparatus. Then, a hologram is developed by placing the developer in a solution.

 After developing, an optical photoresist layer 3, for example, S-1800, is applied to the obtained hologram relief.

 On layer 3 of the optical photoresist, in areas that do not overlap the topography of the electronic hologram, an analog hologram is exposed, which is additionally illuminated with an exposure that is known to be larger than is necessary for exhibiting an analog hologram. The resulting hologram is developed.

 Electronic and analog holograms can be formed either at different levels, or on one.

 In the first case (Fig. 1), before applying the optical photoresist layer 3, the obtained hologram relief is transferred to the sublayer 2, and the additional illumination of the optical photoresist layer 3 is carried out from the side of the sublayer 2.

 Transfer of the obtained relief to the sublayer 2 can be carried out by removing the material of the layer 1 of the electronic photoresist to its entire thickness, for example, by etching, and then removing the remnants of the layer 1 of the electronic photoresist by washing. In this case, additional illumination of the layer 3 of the optical photoresist is from the side of the sublayer 2.

 In the second case (Fig. 2) after development, the obtained relief of the electronic hologram is dubbed through a mask, for example, based on an FPR plate. The killing is carried out, for example, by highlighting with hard ultraviolet radiation. Next, the mask is removed, and the undeveloped areas are removed by re-development.

 After exposure of the analog hologram, the optical photoresist layer 3 is covered with the same mask, additionally illuminated, and then developed.

 The labels thus obtained are applied to the document to be protected using one of the known methods.

Claims (3)

 1. A method of obtaining a relief-phase holographic security label, which consists in the fact that an electronic hologram is exposed to a layer of an electronic photoresist placed on a sublayer made of a material opaque to optical radiation and then developed, characterized in that after the electron is developed onto the obtained relief holograms apply a layer of optical photoresist, expose an analog hologram in areas of the optical photoresist that do not overlap the relief of the electronic hologram, perform an additional hydrochloric illumination optical layer photoresist exposure, certainly more than is necessary for the display of analog hologram, and again manifest.  2. The method according to claim 1, characterized in that before applying the optical photoresist layer, the obtained hologram relief is transferred to the sublayer, and additional illumination of the optical photoresist layer is carried out from the side of the sublayer.  3. The method according to claim 1, characterized in that before applying the optical photoresist layer, the obtained relief of the electronic hologram is blown through the mask, further developed, and additional illumination of the optical photoresist layer is carried out through the same mask.

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