TW201318885A - Data medium intended for printing on liquid toner presses - Google Patents

Abstract

The present invention relates to a data medium intended for printing on liquid toner presses, comprising a substrate coated on at least one of its faces with an adhesion primer suitable for liquid electrophotography, and at least one security element, said printable face coated with the adhesion primer having a non-random relief conferring a Bendtsen surface roughness in the range from 500 to 1500 mL/min. Said relief is in particular visible to the naked eye in raking light.

Description

Information medium for printing on liquid color printing presses

The invention relates to the field of security documents.

More particularly, the present invention relates to a data medium that can be printed on a liquid color printing press; and a method of making the medium.

The medium may be fibrous, in particular by paper preferably having at least 50% by weight of fibers, especially cellulose.

In printing technology, digital printing (especially electrophotography) has developed rapidly. In electrophotography, the use of liquid or powder toner causes static electricity to transfer images directly onto the surface, which results in an anti-fade image.

In electrophotographic techniques, it has proven to be particularly advantageous in liquid toning printer printing (also known as liquid electrophotography or digital lithographic color technology).

More specifically, this technology was developed by Indigo N.V., now part of the Hewlett Packard Group (HP). It is characterized by a combination of electrophotography and lithography: firstly, the liquid toner (also referred to as ink) corresponding to the pattern to be printed is deposited on a static-charged roll, and then electrostatically transferred to the blanket again. On the heated roll. The toner deposited on the hot cloth will liquefy and form an adhesive film which is eventually transferred to the substrate.

When the substrate temperature is lower than the cloth temperature and lower than the melting point of the toner, the toner film is fixed and cured on the substrate, and the toner is allowed to be transferred from the cloth to the substrate. . (E.g., trade name HP ElectroInk ^® products) to achieve high-quality digital printing using liquid toners. These liquid toners typically contain suspended polar pigment particles.

Similar to other digital printing techniques, particularly electrostatic printing (dry electrophotography), liquid toning techniques can electrically control the positioning of such printing particles. Further, in contrast to dry electrophotography, the liquid toner particles may be of a small size, for example, on the order of 1 to 2 microns. The suspended small sized particles advantageously make it possible to print high resolution images with sharp edges and uniform brightness. It also makes it possible to obtain a film of a smaller thickness along the surface configuration of the paper. In addition, liquid toning printers (eg, HP Indigo printers) can print on very wide media such as paper, plastic, and the like.

However, liquid toner inks are known to have low adhesion to fibrous media. In fact, documents printed by liquid electrophotography are easily counterfeited (for example using an eraser or a lancet) without damaging the surface of the media, and thus do not leave any forgery marks.

Therefore, most substrates used for liquid electrophotographic printing must be pretreated to ensure maximum adhesion of the ink. Paper for printing with liquid toner is therefore typically applied via a solution (referred to as "adhesive primer" or "adhesive primer") to promote and improve ink transfer to the media during printing. More specifically, to ensure printing for HP Indigo, papers printed by conventional liquid color printing presses sold by HP must be coated with a specific primer (such as those sold by Michelman).

It is a disadvantage that the use of an adhesive primer coating will enhance the surface adhesion of the paper during the manufacture of the security paper and is detrimental to tracking forgery. In fact, stronger mechanical stress can be applied to falsify the document without damaging the surface of the media, and thus leaving no trace of evidence of forgery. In particular, this surface damage is the separation of the fibers, i.e., the surface fibers are peeled off or partially separated.

Therefore, as far as the applicant knows, liquid electrophotographic technology has never been employed to print security paper (specifically, mechanically forged paper).

Accordingly, there remains a need for a data medium that can be fabricated with anti-counterfeiting (specifically mechanical forgery) and that is suitable for printing on liquid color printing presses.

More specifically, there is still a need for a data medium that meets the identification requirements for printing on liquid-toned printing presses (especially HP Indigo printing) while providing anti-mechanical forgery.

In particular, the present invention is directed to a data medium that meets the aforementioned requirements.

In particular, in accordance with a first aspect of the present invention, the present invention is directed to a data medium for liquid electrophotography (i.e., for printing on a liquid toning printer) comprising at least one face adapted for use in liquid electronics A photographic adhesive-coated substrate and at least one security element having a printable surface coated with an adhesive primer having a regular embossing imparting a Bentsen surface roughness of 500 to 1500 mL/min.

In particular, the substrate is fibrous, but the invention is not limited to fibrous substrates.

Advantageously, the tie paper, in particular consists of at least 50% by weight of fibers, preferably cellulose fibers.

The printable surface preferably has a regular relief that imparts a Bentsen surface roughness of 550 to 1200 mL/min (and more specifically about 700 mL/min).

Preferably, the regular relief extends over the entire printable side of the substrate, in particular the paper.

The inventors have found that by using a printable surface having a specific roughness, it is safer to print the security paper on a liquid color printing press without affecting the printability of the technology.

Modified paper (especially safety paper) surfaces have been proposed. For example, document EP 1 252 389 describes a security paper having a security zone which provides protection against mechanical forgery and has a set of hollow pits on the paper, wherein the depths of the hollow pits are around the pits The maximum thickness of the paper is 50 to 90%. The printing of such papers is of good quality for ink jet printing or laser printing.

Document GB 191501084 also describes a method of processing and printing security paper which is used for compression between dies (other than embossing) so that embossing can be produced in the paper and visible gray is produced (this cannot be reproduced by photography).

However, to the best of the inventor's knowledge, the security media of the present invention have not been proposed, particularly for printing on liquid color printing presses and providing anti-mechanical counterfeiters.

Accordingly, the information media of the present invention demonstrates advantages in several respects.

First, it is well suited for printing on liquid ton printing presses, in particular due to the application of conventional adhesive primers suitable for liquid electrophotography for printing surfaces. In particular, by using HP Indigo-certified adhesive primers and by using common liquid toners (for example, the toner sold by HP under the name ElectroInk ^® ), it can meet the usual liquid color grading sold by HP. The requirements for printing on a printing press (for example, a printing press sold under the name HP-Indigo ws 4050).

In addition, the information medium of the present invention is advantageously displayed on a liquid toning printer Good printability of the brush. In particular, the printability of the media meets the requirements for media certification for Indigo printing, particularly regarding the adhesion of the ink to the printed media and the transfer of the ink between the cloth and the media.

According to another aspect, the invention is therefore directed to a method of printing on a liquid-toned printing press using data comprising at least one substrate coated with an adhesive primer suitable for liquid electrophotography and at least one security element. The media serves as a print medium, and the adhesive-coated surface of the printable surface has a regular relief that imparts a surface roughness of 500 to 1500 mL/min to Bendtsen.

The printable surface preferably has a regular relief that imparts a Bentsen surface roughness of from 500 to 1400 mL/min (specifically from 550 mL/min to 1200 mL/min, and preferably about 700 mL/min).

Moreover, as illustrated in the examples specified below, the media of the present invention (especially paper) has proven to be particularly resistant to counterfeiting attempts (especially mechanical forgery attempts, such as the use of erasers or lancets). In fact, it is quite difficult to forge the paper of the invention printed on a liquid toning printer.

More specifically, mechanical forgery (for example, the use of an eraser or a lancet) will destroy the rough surface and, in particular, the fiber substrate will cause the fibers of its surface to be detached, so the paper will leave traces of attempted forgery. .

Similarly, the print on the material of the present invention cannot be erased (especially using an eraser eraser) without destroying the surface of the media, as indicated by the example designation below. Without wishing to be bound by any theory, it is assumed that the relief of the rough surface of the present invention is easy to capture ink. Attempting mechanical forgery (especially using rubbing During the removal of the ink, it is more difficult to achieve the ink embedded in the pits of the rough surface relief by scraping or erasing.

According to a particularly preferred embodiment, the media of the present invention has one or more chemical or biochemical anti-counterfeiting agents that effect a color reaction on at least one counterfeit agent, as described in more detail below. Therefore, in addition, the data medium of the present invention shows good resistance to chemical forgery attempts. In fact, as illustrated in Example 2, as specified below, the presence of an adhesive primer layer on the surface of the paper does not compromise the sensitivity of the paper to products for chemical counterfeiting.

According to a further aspect, the invention relates to a method of manufacturing a data medium (specifically as defined above) for printing on a liquid-toned printing press, characterized in that it comprises a step consisting of at least the following: (i) Forming regular ridges on at least the surface of the substrate for printing; and (ii) coating the surface for printing using an adhesive primer suitable for liquid electrophotography; the relief formed in step (i) imparts the The Benton surface roughness of the primer-coated printable surface of 500 to 1500 mL/min; the step (ii) is performed before or after the step (i).

Preferably, step (i) is carried out by embossing the surface for printing.

The printable surface preferably has a regular relief that imparts a Bentsen surface roughness of from 500 to 1400 mL/min (specifically from 550 mL/min to 1200 mL/min, and preferably about 700 mL/min).

As described in more detail below, the papermaking process of the present invention can be practiced in accordance with a number of variations. In particular, during the manufacture of the paper, depending on the technology employed and the order of steps (i) and (ii) can be changed, under wet conditions or under dry conditions. A ridge is formed on the surface of the substrate (especially by embossing).

Hereinafter, the expression "printing surface" or "for printing surface" is used to distinguish the two faces of the substrate, and the printing surface refers to those which are subjected to various treatments (embossing, coating) before liquid electrophotographic printing.

More specifically, the term "face that can be printed by liquid electrophotography" or the simple "printable surface" is used to mean the surface of a substrate for printing, which is coated with an adhesive primer to make it suitable for use. Printing on a liquid grading press.

In the variant, the two sides of the substrate are "printed surface" or "for printing surface", or "surface that can be printed by liquid electrophotography" or "printable surface".

Other features and advantages of the data medium and its method of manufacture are apparent from the following description and examples, which are illustrative and not restrictive.

In the following, unless otherwise stated, the expressions "between ... and ...", "from ... to ..." and "from ... to ..." are equivalent. And means to include the limits of the range.

Unless stated otherwise, the expression "having/containing one" shall be taken to mean "having/containing at least one."

Substrate

The substrate contemplated by the present invention is preferably fibrous.

It may comprise paper fibers known to those skilled in the art, such as cellulosic fibers.

According to a particularly preferred embodiment, the substrate is composed of at least 50% by weight of fibers Dimensions (preferably natural fibers).

According to a variant, the fibrous substrate preferably has at least 50% short natural fibers (derived from broadleaf trees).

More specifically, the substrate may comprise a mixture of 5 to 40% long natural fibers (derived from conifers), 50 to 95% short natural fibers (derived from broadleaf trees), and 0 to 20% recycled fibers.

Such short fibers (derived from broadleaf trees) can be used, for example, to promote fiber separation during attempts to mechanically counterfeit.

These natural fibers may be formed partially or entirely of cellulosic fibers, and may in particular be entirely cellulosic fibers.

According to another embodiment, the substrate comprises synthetic fibers, which are selected, for example, from rayon (especially short rayon or viscose) or thermoplastic fibers (especially polyamide, polyester, polyolefin) and / or a mixture of such fibers.

According to a particular embodiment, the substrate comprises at least one mineral fiber. The mineral fibers or the mineral fibers may be present in an amount of from 5 to 35% by weight, based on the total weight of the substrate.

More specifically, they may be selected from the group consisting of vermiculite, sodium citrate and aluminosilicates, carbonates (specifically calcium carbonate), talc, kaolin, aluminum hydroxide, titanium dioxide, and mixtures thereof.

The presence of mineral fibers in particular makes it possible to improve printability by liquid toners and to promote degradation of the surface of the substrate during attempts to counterfeit.

According to another embodiment of the invention, the substrate is a plastic. More specifically, it may be selected from the group consisting of polyesters (especially poly(ethylene terephthalate), polypropylenes, polyethylenes, polyvinyl chlorides, and mixtures thereof) Things.

According to a particular embodiment, the substrate may have a weight of from 60 to 400 g/m ² (specifically 80 to 250 g/m ² ).

This weight is measured according to standard ISO 536.

According to a particular embodiment, the substrate may comprise one or more security elements.

Such security elements known to those skilled in the art are described in more detail below.

According to a particularly preferred embodiment, the substrate comprises at least one chemical or biochemical anti-counterfeiting agent, as explained in more detail below. More specifically, it is a colorless reagent which can cause a color reaction by acid-base chemical reaction, redox reaction or dissolution using an acid, a base, an oxidizing agent (such as a bleach) or a solvent (such as toluene). The chromogenic reaction is visible in the case of counterfeit prints.

For example, the substrate of the data medium of the present invention may incorporate one or more security elements selected from fibers that are invisible in daylight but fluoresce under 365 nm radiation, not visible in daylight but at 365. the particle fluoresces Hilite ^TM forgery-proof and chemical agents it under nm radiation.

The Hilite ^(TM) particles described in application EP 226 367 are, for example, agglomerates of finer fine particles and have a size of about 200 μm.

Adhesive primer

According to an essential feature of the invention, the substrate is at least used for the application of an adhesive surface to an adhesive primer suitable for liquid electrophotography.

As noted above, this is a printing surface treatment that is commonly used for printing on liquid ton printing presses and is intended to ensure maximum adhesion of the ink.

Those skilled in the art can choose the adhesive primer according to their general knowledge. In particular, the amount of primer deposited on the substrate is adjusted according to the characteristics of the substrate and/or liquid toner for electrophotography to obtain good printability.

According to a particular embodiment, the adhesive primer is selected from the group consisting of HP Indigo N.V. certified adhesive primers for HP Indigo digital printing.

More specifically, it can be an adhesive primer sold by Michelman and compatible with digital printing on HP Indigo liquid toning printers.

Therefore, the adhesive primer selected from Michelman name sold to DigiPrime ^® (specific words DigiPrime ^® 1000) or Sapphire ^® products.

The aqueous dispersion-based primer DigiPrime ^® adhesive comprises a copolymer of acrylic acid and of ethylene. Sapphire ^® is an aqueous dispersion of polyethyleneimine.

These adhesive primers are particularly advantageous because they can be adhered to a variety of substrates.

The adhesive primer is preferably selected from aqueous dispersions comprising a copolymer of acrylic acid and ethylene or polyethyleneimine.

The substrate of the present invention coated with an adhesive primer on one side is suitable for printing on a liquid color printing press, in particular an industrial printing machine sold by HP-Indigo NV (such as the HP Indigo printing press ws4050, Ws6000) and commercial presses (such as HP Indigo presses 7000 and 5500).

Adhesive primer coating can be carried out by any of the techniques of coating, dipping, paving, printing or spraying known to those skilled in the art, and more particularly for aqueous adhesive primers.

Thus, in accordance with the present invention, the primer coating system is used in its entirety and/or surface treatment. It is preferred to at least increase the surface of the primer to bond the ink to the surface. Reason.

For example, an air knife coater, a curtain coater, a bar or knife coater, a rod or pen coater, a gate roll coater, a gravure coater, an impregnator can be used. A sizing press, a film transfer device (especially a film press), a printing device (especially a flexographic relief or gravure printing), and a spray device are used.

Advantageously, the coating technique allows the adhesive primer to be applied evenly and allows surface embossing for printing. Therefore, in particular, the so-called "contour" coating is applied, in particular, by a curtain coater or an air knife coater.

By the company HP Indigo also designed to DigiCoater ^® machine for coating the aqueous primer adhesive coating.

According to a particular embodiment, the adhesive primer is applied at a rate of from 0.3 to 5.0 g/m ² (preferably from 0.5 to 1.5 g/m ² , and more preferably about 1.0 g/m ² ) on the printing surface.

Intermediate or impregnated layer

According to a particular embodiment, the data medium of the present invention may comprise at least one impregnate or intermediate layer of a substrate between the surface of the substrate and the adhesive primer, which is comprised of the composition to be applied (also referred to as the impregnate or The coating solution) is formed.

Thus, the method of making the paper of the present invention can include applying the composition to at least the printing surface prior to the step (ii) of coating with the adhesive primer. More specifically, according to an embodiment, the applying step is after the regular embossing (i) is formed on the surface of the substrate for printing and (ii) is applied using the adhesive primer. Before proceeding.

This application step is known to improve the surface quality of the paper. In particular, it makes it possible to homogenize the bottom fiber layer of the paper to provide a more uniform and regular surface, which results in better print quality.

It will be appreciated that in the context of the present invention, when the application is carried out after the relief forming step (i), the application is carried out under favorable conditions such that the thus processed data medium still meets the surface roughness requirements of the present invention. Coating with the primer results in a slight decrease in Bentsen roughness. Those skilled in the art can thus vary the amount of primer deposited to adjust the desired final roughness.

Those skilled in the art can select a composition to be applied that is suitable for the paper and the characteristics of the adhesive primer.

The composition to be applied may comprise a binder (more specifically selected from the group consisting of starch, latex, carboxymethyl cellulose (CMC) and mixtures thereof) and a binder and/or moisture resistance for enhancing the water resistance of the substrate. Agent.

The latex may be selected from the group consisting of acrylic latex, styrene-butadiene latex or butadiene latex, and is more preferably selected from acrylic latex in terms of durability (especially anti-UV and anti-aging).

The composition to be applied may additionally comprise one or more of the same chemical agents as the fiber introducer to enhance protection of the substrate.

According to a particular embodiment, the composition for impregnating the substrate or forming the intermediate layer is applied at a rate of from 1 to 10 g/m ² (preferably about 5 g/m ² ) on the printing surface.

Application can be carried out by any method or device known to those skilled in the art of impregnation or coating, for example by dipping machines, size presses, film presses, gas A knife coater or a knife coater, a curtain coater, a Champion coater, a photographic coater or a film transfer coater (for example, a "Twin-HSM" coater of BTG Co., Ltd.).

Application for forming an intermediate layer or for impregnation can be carried out by any of the techniques of coating, dipping, paving, printing or spraying known to those skilled in the art.

Thus, in accordance with the present invention, the composition used to form the intermediate layer or for impregnation is applied as a whole and/or surface treatment. Preferably, at least the overall treatment is to homogenize the bottom fibrous layer of the paper to achieve a more uniform and regular surface.

For example, an air knife coater, a curtain coater, a bar or knife coater, a rod or pen coater, a gate roll coater, a gravure coater, an impregnator can be used. This process is carried out by a size press, a film transfer device (especially a film press), a printing device (especially a flexographic letter or gravure), and a spray device. Advantageously, impregnation or paving is used (especially by means of an impregnator, a size press or a film transfer device (especially a film press)).

Preferably, the composition for forming the intermediate layer or for impregnation is applied to the printing surface by a size press.

Rough printable surface

According to another essential feature of the invention, the printable surface coated with the adhesive primer has a surface roughness of 500 to 1500 mL/min (specifically 500 to 1400 mL/min, and preferably 550 to 95 Å). Regular relief of 1200 mL/min).

Preferably, the printable surface has a length of less than or equal to 1000 mL/min. Terson roughness.

Preferably, the printable surface has a Bentsen roughness greater than or equal to 550 mL/min.

Preferably, the printable surface has a Bentsen roughness of about 700 mL/min.

Preferably, the relief is a texture visible to the naked eye under side illumination.

Preferably, the regular relief extends over the entire surface of the printable side of the substrate.

The inventors have found that the surface roughness does not affect the quality of printing on liquid ton printing presses, however it is advantageous to increase the difficulty of counterfeiting (especially using erasers and/or lancets), as specified below This is described in more detail in the examples.

Bentsen roughness

The surface roughness is determined by the Bentsen method according to the standard ISO 8791-2 ("Paper and board; determination of roughness/smoothness (air leak methods); Part 2: Bendtsen method").

More specifically, the Bentsen roughness measures the air passage rate (mL/min) between the metal ring and the surface of the substrate. The fully ground metal ring was placed on the test sample, which was then placed on a smooth, flat hard surface. Air is injected into the middle of the annulus under constant pressure and the measurement indicates the rate of air leakage between the annulus and the surface of the paper. The rougher the surface of the substrate, the easier the air leaks and the higher the measurement. Conversely, the less rough the substrate, the lower the measured value will be.

Those skilled in the art can form regular ridges on the surface of the printed substrate. It is suitable for imparting the desired roughness to the printable side to which the adhesive primer is applied.

The printing surface may have a series of "bumps" and "pits" of ridges, more specifically, which are distributed in a repeating pattern.

This relief can advantageously capture the ink in the pit, thus making any counterfeiting attempts more difficult.

All portions of the surface having an average amplitude above the pattern in the relief on the sheet are referred to as "bumps" and all portions of the surface having an average amplitude below the pattern in the relief on the sheet are referred to as "pits".

Preferably, the relief has a lower than 1.6 (preferably less than 1.3) ratio. S _vk and S _pk ("converted depth of valley (or pit)" and "converted height of peak (or bump) respectively) according to standard ISO 25178 and their lateral resolution of 5 μm from Altisurf measurement Calculated by mathematically filtering the 10x10 mm zone of the degree and then using a 0.8 mm Gaussian filter. This mathematical filtering eliminates low frequency values of any deformation (such as folding, lack of flatness, etc.). The 0.8 mm Gaussian filter eliminates structural values greater than 800 μm while maintaining only surface roughness.

According to a particular embodiment, the projections have a narrow, elongated shape with random edges, or a truncated cone or dome shape. However, the pits are wide enough to allow ink to be deposited during printing and to avoid the formation of unprinted dots at the bottom of the pits, thereby ensuring good printability of the substrate.

The projections have a width of, for example, 0.2 to 0.75 mm and a length of 0.5 to 6 mm.

In a practical example of the invention, the printed surface has protrusions of different shapes, in particular unequal lengths. The protrusions are visible to the naked eye under side illumination but The viewer cannot perceive a single repeat and the same easy to distinguish and repeat the same geometric pattern (eg, a circle, ellipse, or polygonal outline) at smaller intervals. Thus, the presence of the protrusions remains fine and has no detrimental effect on the appearance of the print and the appearance of at least one watermark that may otherwise be present.

Such projections may be the same as those sold by their own WITCEL company and having a surface appearance corresponding to the "MARTELE" and "STYLE" papers of Figures 2 and 3.

For example, the protrusions present on the "STYLE" paper are preferred because in the "MARTELE" paper the pits are deeper and narrower and the projections are more rounded, which results in less fiber separation during counterfeiting.

According to a particular embodiment, the convex ridges have an amplitude of 20 to 40 μm, preferably 25 to 35 μm.

It is particularly preferable to have a pointed protrusion (specifically, a non-circular shape). In fact, during the attempted mechanical forgery (e.g., erasing), the fiber separation of the fibrous substrate will be more likely to occur, thus leaving a trace of forgery.

The user can sense the "rough" or "granular" feel of the printed surface by contact. In addition, the ridges are visible to the naked eye under side illumination.

Formation of ridges

This relief can be formed on the surface of the substrate for printing by any of the methods of watermarking, embossing, marking or granulating known to those skilled in the art.

Preferably, the relief is formed by embossing, marking or granulating on the surface of the substrate for printing.

Those skilled in the art can apply any of the techniques of watermarking, embossing, marking or granulating to produce the roughness required to impart the surface to the invention. Suitable for embossing.

Such devices for identifying ridges are described, for example, in document WO 2004/003294.

The rough surface can be obtained, for example, using a device selected in particular from: - an embossing roll; - a watermark roll; - a watermark line; - a cloth print roll; - a textured roll, in particular by pressing Patterning or engraving (specially) synthetic materials (such as rubber) or metal formation; - assembly of wire (especially metal wire) rolls; - marking or granulating felt; and - granulation printing press.

According to a particularly preferred embodiment, the ridge is formed by an embossing device, wherein the sheet is passed between two rolls, wherein at least one of the textured rubber rolls on the side of the surface to be printed is .

The texture of the (equal) rubber roller allows the desired relief to be obtained.

Thus, in addition to the conventional watermarking technique, the relief can be obtained by, for example, a device other than a watermark roller or a watermark line.

According to the first embodiment, the formation of ridges on the surface of the printing paper (specifically by embossing) is carried out under wet conditions during the formation of the paper sheets, more specifically during drainage or during pressing in the papermaking process.

All of the above devices are applicable to this first variant. A variable degree of pressure can be applied to the substrate by such means, in particular to achieve the desired roughness.

In the context of this variant, the embossing, marking or granulation is specifically formed prior to application of the adhesive primer.

Thus, in accordance with one of its variants, the invention relates to a method of manufacturing a data medium (specifically as defined above) for printing on a liquid-toned printing press, characterized in that it comprises at least the steps consisting of: (a) providing at least one substrate having regular embossments; and (b) coating the face with an adhesive primer suitable for liquid electrophotography, the embossments applied in step (a) imparting an adhesive primer The Bentsen surface roughness of the printable surface of 500 to 1500 mL/min.

The printable surface preferably has a regular relief that imparts a Bentsen surface roughness of from 500 to 1400 mL/min (specifically 550 to 1200 mL/min, and more preferably about 700 mL/min).

In particular, the substrate in step (a) can be formed in advance (especially under wet conditions) by embossing, marking or granulating the surface of the substrate.

According to a further embodiment of the invention, the formation of ridges on the printing surface takes place during the drying phase of the papermaking and more particularly by embossing. This embossing step can be carried out under dry conditions using a granulation printing machine, a textured roll or an embossing roll. Such devices can apply pressure and/or heat to the substrate, particularly to achieve the desired roughness.

In the context of this embodiment, the formation of the relief (specifically by embossing) can be carried out before or after coating with an adhesive primer.

Thus, in accordance with another embodiment, the present application is also directed to a method of making a data medium (specifically as defined above) for printing on a liquid-toned printing press, characterized in that it comprises at least the steps consisting of: (c) providing at least one surface coated with an adhesive primer suitable for liquid electrophotography; and (d) forming regular relief on the coated surface (specifically by embossing in particular It is carried out under dry conditions to impart a Bentsen surface roughness of 500 to 1500 mL/min on the face to which the adhesive primer is applied.

The printable surface preferably has a regular relief that imparts a Bentsen surface roughness of from 500 to 1400 mL/min (specifically 550 to 1200 mL/min, and more preferably about 700 mL/min).

The substrate used in the step (c) can be prepared in advance by coating the surface of the substrate with an adhesive primer, as described above.

According to another embodiment, the substrate used in step (c) may be selected from the group of adhesive primer coatings that have been suitable for liquid electrophotography.

According to a variant of the invention, the invention relates to a method for producing a data medium for liquid electrophotography, characterized in that it comprises the step of at least consisting of: (i) at least a substrate surface for printing Forming a regular relief thereon; and (ii) coating the surface for printing using an adhesive primer suitable for liquid electrophotography; the relief formed in step (i) imparts printability to the adhesive primer coating The surface roughness of the Bentson surface is from 500 to 1500 mL/min; the step (ii) is carried out before or after the step (i).

The printable surface preferably has a regular relief that imparts a Bentsen surface roughness of from 500 to 1400 mL/min (specifically from 550 mL/min to 1200 mL/min, and preferably about 700 mL/min).

In the context of the use of a plastic substrate, as described above, the embossing may be performed under pressure by a granulation printing machine, a textured metal roll or an embossing roll, and the rolls may or may not be heated to promote the plastic base. The fiber of the material is separated.

Generally, embossing is preferred over embossing in the wet phase. In fact, embossing in the wet phase can "take off" the surface fibers of the media, which are then more easily separated during the attempt to mechanically counterfeit.

In contrast, since the embossing system is usually carried out under pressure in the drying stage, it tends to enhance the surface adhesion of the fiber, which will allow stronger mechanical stress to be applied during the forgery without causing damage to the surface of the substrate.

Safety element

The data medium of the present invention may include one or more secure elements.

Some or all of this security element is visible.

The security elements, for example, may be integrated with or present on the substrate, in particular the fibrous substrate.

The security elements or the security elements present may have security features of the first, second or third level.

Among these security elements, some are visible to the eye under daylight or artificial light and do not require the use of a particular device. Such security elements include, for example, colored fibers or strips, fully or partially printed wires or wires. These security elements are referred to as the first level.

Other types of additional security elements are only detectable by relatively simple devices, such as those that emit ultraviolet (UV) or infrared (IR) light. Such security elements are, for example, fibers, strips, strips, wires or granules. These security elements are visible or invisible to the naked eye, for example when using Wood's lights When irradiated at a wavelength of 365 nm, it emits light. These security elements are referred to as the second level.

Other types of security components require more advanced devices to detect. When such security elements are exposed to one or more excitation sources simultaneously or non-simultaneously, they may, for example, generate a special signal. If appropriate, the signal is automatically detected to identify the file. Such security elements comprise, for example, tracers in the form of active materials, granules or fibers which generate a special signal when exposed to an optoelectronic, electronic, magnetic or electromagnetic excitation source. These security elements are referred to as the third level.

The data medium may comprise one or more reagents as a security element, which are referred to as chemical or biochemical anti-counterfeiting and/or identification and/or identification reagents, which may each react, in particular, with at least one counterfeit and/or identification and/or identification reagent. .

According to a particular embodiment, the data medium comprises at least one chemical or biochemical anti-counterfeiting agent.

The anti-counterfeiting agent can, for example, prevent the use of at least one of the following compounds to chemically erase the printed matter or the marking made by the laser-irradiated substrate: - an oxidizing agent; - a strong base or a weak base; - a strong acid or a weak acid; - Polar or non-polar solvents.

The anti-counterfeiting agent prevents chemical erasure using an oxidizing agent such as, for example, sodium hypochlorite. In this case, the anti-counterfeiting agent may be selected from the group consisting of: - a derivative of manganese, nickel, cobalt or ruthenium, and in particular a salt thereof; - a p-diaminobiphenyl, a sulfate derivative or a phosphate derivative thereof Object - a derivative of vanadium; - 4,4'-diaminonaphthalene (1,1'); -S,N-o-isoisothiourea;-primuline;- derivatives of hydrazine, such as a diaryl hydrazine (for example, diphenyl hydrazine); or a derivative of thiazole, benzothiazole or aminonaphthalene thiazole.

The anti-counterfeiting agent prevents chemical erasure using a strong base such as, for example, sodium hydroxide and/or a weak base such as, for example, sodium carbonate. In this case, the anti-counterfeiting agent may be selected from the group consisting of: - a derivative of manganese, nickel, cobalt or ruthenium, and in particular a salt thereof; - a colored indicator such as p-nitrophenol, phenolphthalein, solvent green (pyranine) Or a dibenzopyran derivative.

The anti-counterfeiting agent prevents chemical erasure using a strong acid such as, for example, sulfuric acid and/or a weak acid such as, for example, oxalic acid. In this case, the anti-counterfeiting agent may be selected from the group consisting of: - a colored indicator such as a dibenzopyran derivative; - a potassium ferrocyanide added with ferric chloride; or - a thiazole, a benzothiazole or an amine group a derivative of naphthylthiazole.

The anti-counterfeiting agent prevents chemical erasure using a polar solvent such as, for example, ethanol, and/or a non-polar solvent such as, for example, toluene. In this case, the anti-counterfeiting agent may be selected from dyes that are insoluble in water but soluble in oils and solvents. These dyes are particularly useful for coloring petroleum derivatives.

The substrate can comprise, for example, a single anti-counterfeiting agent to prevent chemical erasure by several erased products. It may comprise, for example, manganese sulfate (and preferably chlorinated) Manganese), in order to prevent the use of an alkali (such as, for example, sodium hydroxide) and also the use of an oxidizing agent (such as sodium hypochlorite) to erase the marking, which in both cases appears to show a brown stain on the erase attempt.

The substrate may also contain a plurality of anti-counterfeiting agents, respectively, for preventing chemical erasure using a plurality of erasing products, in particular by appearing to display the color development of each erasing product. It may also contain, for example, a thiazole derivative and a dibenzopyran derivative, which are respectively used to prevent chemical erasure using an oxidizing agent (such as sodium hypochlorite) by the appearance of a special stain showing an orange stain of an erase attempt. The use of an acid (such as sulfuric acid) can be prevented by the occurrence of a special stain showing the blue stain of the erase attempt to prevent chemical erasure using a base such as sodium hydroxide and finally by the appearance of a special stain showing a pink stain on the erase attempt. Chemical erasure.

The data medium may comprise at least one structure for authentication and/or identification, and the security elements may be at least partially or even entirely covered by a structure for authentication and/or identification. The structure for identification and/or identification may be selected from at least one of the following: watermarking, optically variable elements (such as holograms), stripping elements, foils, patches, security threads, and printing.

Safety object

The information medium of the present invention may form part or all of a security object.

Accordingly, the invention further relates to a security article, in particular a security document, comprising, in particular consisting of, the above-mentioned data medium.

More specifically, the security object can be a security document, in particular selected from a payment instrument (specific banknotes or checks), identification documents (specific identification cards, driver's licenses, visas or passports, as well as subpoenas, labels, Degree certificate, stamp).

According to an embodiment, it is a check, a voucher, a label, a degree certificate, a stamp.

The invention will now be described by way of the following examples and illustrations.

These examples are of course used to illustrate and not to limit the invention.

Example 1

1.1 The method of making the paper of the invention

Substrate

The base paper based Laserguard ^®, which is a 65% short fiber, 25% long fiber and 10% recycled fiber and containing 22% of mineral filler (e.g., kaolin).

In particular, the paper has standard CBS1 chemical protection.

The security paper comprising as an element of a watermark, an invisible visible colored synthetic fibers and synthetic fibers colored with daylight fluorescent but the radiation at 365 nm, invisible in daylight but fluoresce at 365 nm of radiation particles Hilite ^TM And chemical or biochemical anti-counterfeiting reagents.

Generation of ridges

The paper ("Paper-1") was linearly watermarked in the wet stage and then embossed by a textured solid rubber roll and an embossed pattern was formed. Its "STYLE" pattern is shown in Figure 3.

In comparison, straight watermarked paper ("Paper-2") but it does not undergo an embossing step.

middle layer

After drying, the two faces of the two samples were impregnated on a size press using starch, latex, binder, and chemical agents (such as those introduced at a rate of about 5 g/m ² ).

Adhesive primer

After drying, the use of an air knife coater and is sold authenticated DigiPrime1000 ^® HP Indigo primer ratio of 1.0 to 1.5 g / m ² in coated paper 1 and paper -2 change of surface mass Michelman Corporation.

In comparison, Paper-3 was not coated with the adhesive primer.

1.2. Evaluation of such papers

Bentsen roughness

The inventive paper 1 having undergone the embossing step had a Bentsen roughness of 750 mL/min, while the comparative paper-2 had a Bentsen roughness of 440 mL/min. This roughness is measured after coating through the adhesive primer.

Printing on liquid color printing press

The paper was printed on a HP Indigo ws 4050 press with good printing results.

The surface roughness of Paper-1 of the present invention therefore does not affect the printability of liquid electrophotography in any way.

Anti-mechanical forgery

test

The mechanical forgery test consists of using a white eraser and/or a lancet to attempt to erase printed characters from the paper. This mechanical forgery test was performed on black and red printed characters.

result

The forgery can be assessed by marking the symbol "-" when the forgery is invisible and marking the symbol from "+" to "+++" when the forgery becomes more visible. Visualization.

These results are summarized in the table below.

The printing of non-inventive paper-2 having an unembossed smooth surface can be easily erased using an eraser without damaging the surface of the paper, and thus there is no evidence of forgery. In the case of the non-inventive paper-2 having an unembossed smooth surface, the eraser is invisible to the red character and the black character when viewed under reflected light and transmitted light. The characters can be erased fairly easily, with no fiber separation visible in the erased area.

On the contrary, it is quite difficult to complete the forgery of the inventive paper 1 having the roughness of the present invention without surface deterioration. In addition, the forgery of the paper-1 is visible because the erased characters are still slightly visible. The embossed structure traps the ink in the pits of the relief so that the characters are not erased and the surface of the paper is not deteriorated at the same time. Therefore, erasing makes the surface condition of the paper of the present invention less clean and thus makes counterfeiting attempts obvious.

During the falsification using a lancet or using a white eraser + lancet, both papers exhibited fiber separation and the paper-1 of the present invention was more pronounced.

Chemical forgery

test

The reactivity of these papers to chemical counterfeiting was tested according to the "CBS1" standard and using a non-polar solvent (toluene).

The touch test according to the CBS1 2cm protocol consisted of applying a precise amount of reagent at a precise concentration (acid, base, oxidant, etc.) on a defined area (circle of 2 cm in diameter) according to the standard. The reagents react with those contained in the paper and result in a color reaction of the substrate.

A Delta E measurement is then performed, which corresponds to the difference in hue between the initial substrate and the colored reaction zone.

Therefore, the standard CBS1 specifies the Delta E minimum of the paper to be protected.

Chemical forgery tests were performed on portions of the printed image with sky blue and emerald green, gray ink areas and black printed content.

result

These results are shown in Table 1 below.

These papers all show that after chemical forgery, counterfeiting is confirmed by irreversible color development caused by chemical anti-counterfeiting agents contained in the paper matrix. Furthermore, the ink could not be completely removed from the paper-1 of the present invention.

Papers 1 and 2 made on smooth substrates and embossed substrates are shown according to CBS1 The degree of chemical reactivity to strong acids, bases, bleaches and solvents is comparable to that of paper 3 coated without an adhesive primer.

Therefore, coating with the adhesive primer does not affect the chemical reactivity required for the security paper in any way.

The color of the counterfeit surface of the paper-1 of the present invention is more unclean than the paper-2, and thus the forged system of the paper-1 of the present invention is more visible.

The invention is not limited to the examples.

1‧‧‧Information Media

2‧‧‧Safety line

3‧‧‧Safety components

Figure 1: Schematic representation of a data medium (1) (e.g., a check) of the present invention having a security thread (2) and one or more security elements (3) (e.g., not visible in daylight but at 365 nm radiation) Fluorescent fibers or particles, or chemical or biochemical anti-counterfeiting agents that exhibit a color reaction with at least one counterfeit agent).

Figures 2 and 3: Photographs of "MARTELE" and "STYLE" papers, respectively.

1‧‧‧Information Media

2‧‧‧Safety line

3‧‧‧Safety components

Claims (20)

A data medium for liquid electrophotography comprising at least one surface coated with an adhesive primer suitable for liquid electrophotography and comprising at least one security element coated by an adhesive primer The surface has a Bendtsen surface roughness imparted in the range of 500 to 1500 mL/min (specifically 500 to 1400 mL/min, preferably 550 to 1200 mL/min, and more preferably about 700 mL/min) Regular embossing of degrees. As in the data medium of claim 1, the embossing is formed by repeatedly arranged bumps and pits, which are specifically tied to the texture visible to the naked eye under side illumination. The data medium of any one of the preceding claims, wherein the relief has a lower than 1.6 (preferably less than 1.3) ratio. The data medium of the above-mentioned claim, the projections having a narrow elongated shape having a random edge, preferably having a width of 0.2 to 0.75 mm and a length of 0.5 to 6 mm. The data medium of claim 2 or 3, wherein the relief has an amplitude of 20 to 40 μm, preferably 25 to 35 μm. A data medium according to any one of the preceding claims, wherein the substrate is fibrous, in particular composed of at least 50% by weight of fibers, preferably cellulose fibers. A data medium according to any one of the preceding claims, wherein the security element is selected from a chemical or biochemical anti-counterfeiting agent that produces a color reaction to at least one counterfeit agent. A data medium as claimed in any one of the preceding claims, comprising at least one bit An intermediate layer or impregnate between the surface of the substrate and the adhesive primer, the intermediate layer or impregnate being formed from a composition applied to the substrate, in particular comprising at least one binder selected from the group consisting of : latex, starch, or carboxymethyl cellulose (CMC). A data medium according to any of the preceding claims, comprising printing by liquid electrophotography. A method of manufacturing a data medium for liquid electrophotography, as defined in any one of claims 1 to 9, characterized in that it comprises the step of at least consisting of: (a) providing at least one a substrate having a regular relief on the surface; and (b) coating the surface with an adhesive primer suitable for liquid electrophotography, the relief applied in step (a) imparting the coating to the adhesive primer Bentsen surface roughness of 500 to 1500 mL/min on printable surface. A method of producing a data medium for liquid electrophotography, as defined in any one of claims 1 to 9, characterized in that it comprises the step of at least consisting of: (c) providing at least one face a substrate coated with an adhesive primer suitable for liquid electrophotography; and (d) forming regular relief on the coated surface (specifically by embossing, particularly under dry conditions), The Bentsen surface roughness of the surface to which the adhesive primer is applied is from 500 to 1500 mL/min. A method of manufacturing a data medium for liquid electrophotography, as defined in any one of claims 1 to 9, characterized in that it comprises at least a step consisting of: (i) forming a regular relief on at least the surface of the substrate for printing; and (ii) coating the surface for printing using an adhesive primer suitable for liquid electrophotography; The relief formed in (i) imparts a Bentsen surface roughness of the adhesive-coated printable surface of 500 to 1500 mL/min; and step (ii) is performed before or after step (i). The method of forming any of the items 11 and 12, wherein the step of forming the regular ridges is by embossing, marking or granulating means (specifically by textured rolls (especially synthetic materials (preferably The rubber is rolled). The method of forming the rule embossing (i) (specifically, embossing, marking or granulating) is applied under wet conditions and applied to the adhesive primer (as in any one of claims 12 and 13). Ii) Before the step. The method of any one of claims 12 to 14, wherein the regular ridge forming step (i) (specifically embossing) is under dry conditions and prior to the coating (ii) step of the adhesive primer or After that. The method of applying the adhesive primer is carried out by a coating device (specifically, an air knife coater), as in any one of claims 10 and 12 to 15. The method of any one of claims 10 and 12 to 16, comprising applying an intermediate layer or impregnate to the at least the surface for printing (specifically) using the solution prior to the coating step using the adhesive primer In the step, the solution comprises at least one binder: latex, starch or CMC. A method for printing on a liquid color printing press, which uses a data medium a printing medium having a substrate coated with an adhesive primer suitable for liquid electrophotography on at least one side and at least one security element having a printable surface coated with an adhesive primer having a rating of 500 Regular embossing of Bentsen surface roughness in the range of 1500 mL/min (specifically 500 to 1400 mL/min, preferably 550 to 1200 mL/min and more preferably about 700 mL/min), the method is included The step of liquid color printing press printing. A security article comprising, in particular, a data medium as defined in any one of claims 1 to 9. A security article as claimed in the preceding claims, wherein it is a security document, in particular selected from a payment instrument (specific banknote or check), an identification document (specific identification card, driver's license, visa or passport, and preferably a check, Subpoenas, labels, stamps, degree certificates).