MX2008005960A - Integrating non-elongated security particles in value documents - Google Patents

Abstract

A coherent sheet-like or tape-like product (10) adapted to be integrated into value products or documents, comprises:- non-elongated security particles (14) in the form of metal particles or metal coated particles;- a paper or plastic compatible binder (12). The sheet-like or tape-like product allows a better controllable concentration of the security particles and an easy integration of the security particles into the value documents.

Description

INTEGRATION OF SECURITY PARTICLES NOT EXTENDED IN VALUE DOCUMENTS FIELD OF THE INVENTION The present invention relates to a coherent product similar to canvas or similar to tape with security particles. According to a second aspect, the present invention is also related to a valuable document comprising the product similar to canvas or similar to tape. According to a third aspect, the invention relates to two methods for manufacturing a product similar to canvas or similar to tape.

BACKGROUND OF THE INVENTION It is known how to integrate security particles into substrates for purposes of identifying or authenticating valuable documents. Documents US-A-4, 08, 156, EP-B-0 236 365 and EP-B-0 897 569 are only examples of prior art documents that describe these valuable documents. US-A- 265, 03 discloses a method of integrating security particles in the form of metal fibers into a fibrous structure, such as paper. In addition, the difference in specific gravity between metallic fibers and paper-like material makes a homogeneous distribution of metallic fibers on a difficult paper substrate, if precautions are not taken. The precautions taken in US-A-4, 265, 703 consist in submitting a set of metal particles to a water-soluble binder bath to make a coated assembly. The water-soluble binder is polyvinyl alcohol or starch. The fiber assembly is then dried and cut into predetermined lengths of agglutinant-fiber agglomerates. The agglomerates are mixed with paper particles to form a structure similar to canvas where the metal particles are distributed homogeneously. The binder material serves as a material to separate the filaments. Despite the successful application of this method, variations in concentrations of the particles in the substrate are experienced. When the level of security to be provided by particles also depends on the concentration of the particles in the substrate, variations in concentrations are unacceptable. The method described in US-A- 265, 703 can also be applied to incorporate metal particles in limited positions in valuable documents. The limited positions can be in the form of bands or strips. Experience has shown that it is difficult to maintain the width of the bands or strips within predetermined narrow limits. Also, some dimensions can not be obtained, for example very small widths. Again, when the level of security provided by the metal particles also depends on the exact geographical position of the metal particles in the valuable document, too large a variation in geographical position is not acceptable.

BRIEF DESCRIPTION OF THE INVENTION An object of the present invention is to avoid the drawbacks of the prior art. Another objective of the present invention is to provide greater control of the concentration of security particles in the substrate of a valuable document. Still another object of the present invention is to provide accurately determined geographical locations with security particles within a security document. Yet another object of the present invention is to provide a solid method for integrating security particles into a valuable document, largely independent of the way valuable documents are made. According to a first aspect of the present invention, a coherent product similar to canvas or similar to tape adapted to be integrated into valuable products or documents is provided. The product comprises: non-elongated security particles; a binder compatible with paper or plastic. In the context of the present invention, the terms "valuable documents" refer to all types of valuable documents, such as banknotes, obligations, passports, credit cards, access tickets, etc. The safety particles must be integrated in or on the documents. The terms "non-elongated security particles" are used in order to make a distinction with fiber-like products and refer to particles where several dimensions (eg, length, width, depth) may vary from each other only to a degree limited, for example, to a factor less than 10, preferably less than 6, for example, less than 5. The terms "non-elongated particles" comprise powders, small spheres, pigments and the like. The absolute values of the dimensions are less than the final thickness of the final valuable documents. In order to function as "security particles", the particles have parameters, which are characterized as being detectably different from the substrate material. The detectable difference can take several forms, such as optical difference (for example, difference in reflection or absorption or transmittance), electrical conductivity, magnetic coercivity, harmonic response, microwave reflection, microwave absorption or the like. In addition to a type of non-elongated safety particles, other safety particles and / or particles without safety or identification function can also be added. For example, it may be advantageous to add particles, which are characterized by affinity with the substrate already at this stage in the product similar to canvas or ribbon-like. In this regard, when the substrate comprises paper, it may be advantageous to add cellulose particles, after the security particles. The non-elongated security particles may be present in the product similar to canvas or similar to tape in a concentration ranging from 10 × 10"6 to 1.0 × 10 ~ 3 g / cm 2. The terms" binder compatible with paper or plastic "are refer to a binder that can be easily integrated into a paper or plastic matrix The binder disappears during the integration process or can be incorporated into the paper or plastic Advantageously, the binder is a water-soluble binder This makes the binder particularly advantageous for the binder. For example, the binder can be selected from the group comprising polyvinyl alcohols, methylcellulose ethers, hydroxypropylmethylcellulose, ethylene oxide polyethers, acrylic acid polymers or acrylic copolymers.

As a preferable example, methylcellulose has the following advantages as a binder in this context: it is an economical binder material, any form or mixture can be made under basic laboratory conditions, reuse of methylcellulose and the material mixed with methylcellulose is possible. The methylcellulose binder material disintegrates easily when heated. The product similar to tape or canvas-like, as such, has only a transient existence. Its objective is to better control the concentration of safety particles and the geometry of the safety particle region. This control is done at the level of the material similar to tape or similar to canvas and not at the level of the final valuable document or final valuable product. Finally, the product similar to canvas or similar to tape must be integrated with the valuable document or valuable product. Once the integration step is done, it is no longer possible to extract intact the ribbon-like or canvas-like material from the valuable document or valuable product. Throughout its duration, the product similar to tape or similar to canvas must remain coherent and strong. At the time of integration with the valuable document or valuable product, the product similar to tape or similar to canvas must cease to exist as such. Preferably, a plasticizer can be added and mixed together with the security particles and binder material in the solvent. The plasticizer makes the product similar to canvas or similar to more resistant and more flexible tape. An example of a plasticizer is polyethylene glycol. Another example is polyvinyl alcohol. The plasticizer can also have another function, particularly in case the product similar to canvas or similar to tape is integrated into valuable paper documents. Papermaking is done in a very humid atmosphere with a large amount of water. The correct amounts of the plasticizer present in the product similar to tape or similar to canvas can control the time required for the process of disintegration of the material similar to tape or similar to canvas and its integration into valuable paper documents. In addition to plasticizers, titanium dioxide (Ti02) and carbonates can also perform this function. The greater the amount of plasticizer, Ti02 or carbonates, the longer the disintegration process takes. Also the color additives can be mixed together with the security particles and the binder material. This can give a particular and predetermined color to the product similar to canvas or ribbon-like. The given color can mask the presence of safety particles. Advantageously, when used in particular with paper as a substrate material, the canvas-like or tape-like product becomes porous, for example, by making small perforations in the canvas-like or tape-like product. The porosity facilitates the evacuation of water during the integration of the product similar to canvas or similar to tape on paper substrate. According to a second aspect of the present invention, a valuable document or a valuable product is provided in which or on which the product similar to tape or canvas-like product has been integrated. According to a third aspect of the present invention, two methods for manufacturing the product similar to canvas or tape are provided. The first method comprises the following steps: a) supplying a binder in liquid form or dispersed form, for example, in a solvent, such as water; b) supply non-elongated particles that will function as safety particles; c) mixing the particles in or with the binder; d) molding the binder with the particles; drying or heat-treating the binder molded with the particles to form a coherent product similar to canvas or ribbon-like. One of the advantages of the present invention results from step c): the particles are mixed with binder material in a controllable and determinable concentration. If the abstraction is made of non-safety particles, >of other possible additives and the solvent, the only parameters are the amount of safety particles, the amount of binder material and the degree of the mixture. The amount of security particles as well as the amount of binder material can be accurately determined. The degree of the mixture can be easily controlled, for example, by the revolutions of a screw in the mixture and by the temperature of the process. The particles mixed in the binder are molded and dried or heat-treated, for example, to vaporize the solvent and form a coherent product similar to canvas or ribbon-like. The concentration of the security particles in the product similar to canvas or similar to tape and the variations present herein can be determined in the product similar to canvas or similar to tape before any integration in the final product. The concentration of the safety particles in the product similar to canvas or similar to tape is directly related to the concentration of the safety particles in the final product or final document. In one embodiment of the invention, the ribbon-like or canvas-like product can be molded using an applicator, such as a tangent blade. The method further comprises the step of cutting the product similar to canvas or ribbon-like. This additional step has the advantage of accurately determining the dimensions of the position where the safety particles can be found. In addition, this exact determination is made in advance before the final valuable product or final valuable document is manufactured. This means that this separate and previous cut makes the method more robust and less dependent on the particular way of integrating safety particles into the final valuable document or into a valuable product. As a subsequent step, the binder dried with the security particles is integrated into the substrate of the valuable document or valuable product. The second method comprises the following steps: a) providing a substrate; b) providing non-elongate security particles in the form of metal particles or metal coated particles in the substrate; c) molding or spraying binder in liquid or dispersed form in the safety particles; d) drying or heat treating the combination of binder and security particles so as to obtain a coherent product similar to canvas or tape separable from the substrate. In this second method, the concentration of safety particles and the geometry of the region with safety particles is controlled mainly in step b).

Brief description of the figures. The invention will now be described in more detail with reference to the accompanying figures, wherein: FIGURE 1 is a drawing of a molded and dried binder mixed with non-elongated security particles; FIGURE 2a (top view) and FIGURE 2b (cross section) show a valuable paper document; FIGURE 3a (top view) and FIGURE 3b (cross section) show a valuable plastic document.

Description of preferred embodiments of the invention FIGURE 1 shows a product 10 similar to a canvas or similar to a tape as a result of the method of the invention. The product 10 similar to a canvas or similar to a belt comprises a molded and dry solvent with the binder 12 mixed with the non-elongated security particles 14. The security particles 14 can be, for example, powders or glass particles. As an example, the glass particles have a diameter ranging from 0.1 μm to 30 μm. The product 10 similar to canvas or similar to tape is made in the following manner: a) an amount of binder such as methylcellulose is poured into a container filled with a solvent such as water; b) a predetermined amount of non-elongated particles 14 is poured into the same container; c) the particles 14 are mixed in methylcellulose in order to obtain a distribution as homogeneous as possible; for example, the amount of particles can range from 0.1 g of particles per liter of solvent - methylcellulose to 4.5 g of particle per liter of solvent - methylcellulose, for example, from 0.3 g / l to 1.5 g / l; d) the solvent in aqueous suspension - methylcellulose 12 - particles 14 are poured on a flat surface, for example, a metal surface; e) the poured mixture is leveled to a predetermined thickness, for example, a thickness varying between 30 μm and 500 μm, for example between 60 μm and 300 μm; This leveling can be carried out by means of a leveling strip, for example, by clearing with a tangent blade; f) the leveled mixture dries; g) the dry mix can be cut to the desired widths and lengths. Any control on the concentration itself and on the variation of the concentration of the particles 14 in methylcellulose can be carried out in the product 10 similar to canvas or similar to tape. Any product similar to canvas or similar to tape that does not meet the concentration specifications can be recovered. The cut to the desired width can allow to avoid side effects in the concentration, if there are any. The concentration in the product similar to canvas or tape-like can encompass, for example, from 0.05 g / m2 to 10.0 g / m2, for example, from 0.1 g / m2 to 1.0 g / m2, for example, 0.5 g / m2 . FIGURE 2a is a top view and FIGURE 2b is a cross section of a valuable document with a substrate 22 of paper and with two small bands 24, 26 comprising non-elongated particles. An example of this valuable document can be a banknote. The two small bands 24 originate from the product 10 similar to canvas or ribbon-like, which has been cut prior to the desired width. As a result, the width can be determined more accurately than in the case of the prior art where loose particles are being integrated into the paper substrate during the papermaking process. If the binder material is methylcellulose dissolved in a solvent, such as water, it can be partially or completely dissolved during integration into the paper substrate as a result of the water used during papermaking and the heat produced during papermaking. However, this "disappearance" has no negative influence on the concentration and distribution of the particles in the document. FIGURE 3a is a top view and FIGURE 3b is a cross section of a valuable document 30 with a plastic substrate 32 and with a layer 34 comprising particles. An example of this valuable document can be a credit card or a bank plastic bill. The valuable document 30 can be made by laminating the product 10 similar to canvas or similar to tape with the particles not elongated between two sheets 32 of plastic. Again, if methylcellulose dissolved in a solvent such as water is used as a binder material, it may disappear partially or completely as a result of the heat generated during the rolling process.

Claims (10)

1. CLAIMS 1. A coherent product similar to canvas or similar to tape adapted to be integrated into documents or valuable products, characterized in that the product comprises: - safety particles not elongated a binder compatible with paper or plastic.
2. 2. A product similar to canvas or similar to tape according to claim 1, characterized in that the product similar to canvas or similar to tape has a concentration of safety particles ranging from 1.0x10"6 g / cm2 to 1.0x10. ~ 3 g / cm2 3. A product similar to canvas or similar to tape according to claim 1 or 2, characterized in that the binder is water-soluble A product similar to canvas or similar to tape according to claim 3, characterized in that the binder is selected from the group comprising polyvinyl alcohols, methylcellulose ethers, hydroxypropylmethylcellulose, ethylene oxide polyethers, acrylic acid polymers or acrylic copolymers. 5. A product similar to canvas or similar to tape in accordance with Any of the preceding claims, characterized in that the product also comprises a plasticizer, titanium dioxide or carbonates 6. A similar product to a canvas or similar to tape according to claim 5, characterized in that the plasticizer is polyethylene glycol or polyvinyl alcohol or a combination of both. 7. A product similar to canvas or similar to tape according to any of the preceding claims, characterized in that the product is provided with porosities to facilitate the evacuation of water. 8. A valuable document characterized in that it comprises a product similar to canvas or similar to tape according to any of the preceding claims. 9. A method for making a product similar to canvas or ribbon-like according to any of claims 1 to 7, characterized in that the method comprises the following steps: a) provide a binder in liquid or dispersed form; b) providing non-elongated security particles; c) mix the particles with the binder; d) emptying and molding the binder with the particles; e) drying or heat-treating the binder molded with the particles to form a product similar to canvas or ribbon-like. A method for the production of a product similar to canvas or similar to tape according to any of claims 1 to 7, characterized in that the method comprises the following steps: a) providing a substrate; b) providing non-elongated security particles on the substrate; c) emptying or nebulizing a binder in liquid or dispersed form over the security particles; d) drying or heat treating the combination of the binder and security particles so that a product similar to a canvas or ribbon-like product that is separable from the substrate can be obtained.