LT4281B - Layered product comprising diffraction structure - Google Patents

Abstract

The invention belongs to the sphere of multilayer materials and can be used for protecting documents against forgery. The layers are placed in the following way: transparent stabilising layer, which is covered by a layer of photopolymer composition, the components of which start to shine under the integrated ultraviolet beams, enabling to identify documents in an unseen part of the spectrum, layer of reflection, layer of glue and basis. The diffracting structures are placed in between the layers of photopolymer composition and the layer of reflection. The stabilising layer is covered by a liquid photopolymer composition. The diffracting structures inside a photopolymer composition are formed mechanically, by pressing a hard matrix with relief of diffracting structures to the photopolymer composition. By lighting with ultraviolet beams, the photopolymer composition hardens and is separated from the matrix. The formed diffracting structures stay inside it; they refract the beams of light. After that, the layer of reflection is formed; a layer of glue covers it. The signs with finished composition of diffracting structures are cut out of multilayer material and stacked on the documents.

Description

The invention relates to a multilayer material with diffractive structures, which is intended for protection of documents against forgery. It cuts out signs and glues on documents.

Multilayer materials of various hot-pressed films with diffractive structures or holograms are known, for example, from English Patent No. I70S32AI. They are glued to the substrate and differ in the layers of materials used, in the adhesive and optical properties of the individual layers. It is characterized by sophisticated production technology and insufficient degree of document protection.

The patent specification LR 3327 discloses another multilayer material with diffractive structures. It has a clear stabilizing layer, in which the intermediate layer, the first layer of lacquer, the reflection layer, the second layer of lacquer and the layer of glue are arranged in the order. These layers form a multilayer material. Between the first and second varnish layers, the diffractive structures embedded in the light are refracted, such as mesh, holograms, kinegrams, etc. The multilayer material is glued to the substrate by a thermoclimate layer.

The diffractive structures illuminated through the stabilizing layer, the interlayer, and the first layer of the varnish, and the diffused light rays through these layers are reflected to the observer.

The stabilizing layer of the described multilayer material is usually made of a heat-resistant, transparent film of very high optical quality, for example, a complex polyester.

The intermediate layer consists of an evenly spread adhesive on the stabilizing layer. this is applied with the first coat of varnish. .A reflective layer is formed on the first coat of varnish. This is best done by dusting the surface with metal powder such as aluminum or by using dielectrics.

The diffractive structures are embossed in a heated matrix through the reflective layer onto the first layer of lacquer. The reflective layer is then coated with a second layer of lacquer and the latter with a layer of thermocouples to attach the multilayer material to the substrate.

-2EN 4281 B

During gluing, the adhesive layer is heated through a stabilizing layer which distributes the resulting heat evenly and passes through all layers. The multilayer material adheres strongly to the substrate, causing the layers and diffractive structures to be disassembled to remove it.

A method of manufacturing a multilayer material with diffractive structures comprising coating a stabilizing layer with an adhesive followed by a first coating of a lacquer to form a reflective layer by powdering the surface with a heated matrix through the reflective layer or embossing directly onto the first lacquer layer. is applied with a second coat of varnish, the latter with a layer of thermocouples which, when heated through a stabilizing layer, adheres to the substrate.

The marks made from this multilayer material also do not provide sufficient protection against forgery, since the formed diffractive structures are only identified in the narrow visible part of the light spectrum and, moreover, the thermal pressure matrix contaminates the matrix of the diffractive structures and reduces its durability.

The object of the invention is to increase the protection of documents against forgery by extending the limits of identification to the invisible part of the spectrum and simplifying the manufacturing technology.

This problem is solved by the multilayer material according to the general part of claim 1, characterized in that under the stabilizing layer there is a UV polymeric, glowing components, and the diffractive structures are the photopolymeric composition and the reflective layer.

The advantages of the patented multilayer material include the fact that the UV-embedded components embedded in the photo polymeric composition in red, yellow, green or other colors enable identification of documents in the invisible part of the spectrum.

In addition, the semi-transparent reflection layer can further identify postings, stamps, photographs, etc. under the sign, while the relief height of the diffractive structures 0.0i-r0.3pm achieves maximum absolute and relative diffraction efficiency.

The method of manufacturing a patented multilayer material according to the general part of Claim 4 enables the manufacturing technology to be simplified by incorporating UV-light components into the liquid photo-polymeric composition, thereafter applying a stabilizing layer and mechanically compressing a solid matrix with diffractive structures.

-3LT 4281 B structures in the relief of the photopolymeric composition layer, then curing the photopolymeric composition layer by cold ultraviolet polymerization and separating the matrix.

This method of production is good because it is a Cold rather than a thermal process used in the above methods. The liquid photo-polymeric composition may be applied to a sliding film by passing between rollers. By adjusting the compression force of the rollers, various layer thicknesses can be obtained.

The invention will be further described with reference to one embodiment of the drawing. It shows a multilayer material consisting of layers arranged in the following order: stabilizing layer 1, photopolymer composition containing ultraviolet light components, layer 2, reflective layer 3, adhesive layer 4, base 5 and diffractive structures 6 between photopolymer composition 2 and reflection 3 layers.

The stabilizing layer 1 is formed from a heat-resistant and optically transparent polyester, lavender or polycarbonate film. In order to improve the surface adhesion of this layer, it is treated with a mixture of oxygen and nitrogen in plasma or jet fibers of various gas ions.

The layer 2 of the photopolymeric composition having ultraviolet fluorescent components forms diffractive structures 6 having a relief height of 0.01-f-0.3. Such parameters allow to obtain the maximum absolute and relative diffraction efficiency.

The reflection layer 3 is formed of aluminum by vacuum evaporation. Its thickness may be 0.1-rlOOnm. By choosing a layer thickness within a given range, you can create a layer of the desired transparency.

The adhesive layer 4 may be formed from cold or thermal adhesive.

From the formed multilayer material, a mark is cut with the final composition of diffractive structures 6 and glued to the substrate 5.

Through the stabilizing layer 1 and the photopolymer composition layer 2, the light-refracting diffractive structures 6 and the scattered light rays from the reflecting layer 3 are reflected to the observer.

The process for producing the patented multilayer material comprises the following operations: to improve the surface adhesion of the stabilizing layer 1, plasma or oxygen jet beam is applied to the surface of the stabilizing layer 1 and then it is roll-pressed or otherwise coated with liquid photopolymeric composition 2. by pressing a hard metal or

-4LT 4281 B semiconductor matrix with diffraction pattern relief on the photopolymer composition 2. The surface of the matrix is coated with a protective anti-adhesive layer. Upon exposure to ultraviolet light, photopolymer composition 2 hardens and separates from the matrix. In this way, embossed diffractive structures are retained there. Then a reflective layer 3 is formed and a layer of glue 4 is applied thereto, by means of which the multilayer material is glued to the substrate 5.

Claims (4)

DEFINITION OF INVENTION A multilayer material with diffractive structures (6) comprising a stabilizing layer (1), a reflective layer (3), an adhesive layer (4), characterized in that a layer (2) of a photopolymeric composition is formed beneath the stabilizing layer (1). which is embedded in the ultraviolet light, the luminous components, and the diffractive structures (6) are between the layers of the photopolymeric composition (2) and the reflection (3). 2. The multilayer material of claim 1, wherein the reflective layer (3) is semi-transparent. 3. The multilayer material according to claims 1-2, characterized in that the relief height of the diffractive structures (6) is 0.01-5-0.3um. A method of manufacturing a multilayer material with diffractive structures (6) according to claim 1, wherein a reflective layer (3) is formed which is coated with an adhesive layer (4), characterized in that UV-luminous components are added to the liquid photo-polymeric composition (2). thereafter it is coated with a stabilizing layer (1) and the diffractive structures (6) are formed by mechanically pressing a solid matrix with the relief of the diffractive structures onto the photopolymer composition layer (2), then hardening the photopolymer composition layer (2) by separating it tric.