WO2015092741A1

WO2015092741A1 - Synthetic multilayer substrate

Info

Publication number: WO2015092741A1
Application number: PCT/IB2014/067087
Authority: WO
Inventors: Henri Rosset
Original assignee: Arjowiggins Security
Priority date: 2013-12-20
Filing date: 2014-12-18
Publication date: 2015-06-25
Also published as: FR3015355A1; FR3015355B1; EP3083244A1

Abstract

A synthetic multilayer substrate, comprising: - a compressible core structure (10), comprising a non-fibrous polymer material, having two faces, and - two protective layers (12) that are not fully opaque, made from a non-polyethylene material, each having an inner face and an outer face, each inner face being in contact with a corresponding face of the core structure.

Description

Multilayer synthetic substrate

The present invention relates to substrates used in the field of the manufacture of valuable documents and security.

Background

Currently, secure documents such as banknotes are mainly made from paper substrates. Indeed, the latter have many advantages: they have in particular a very good impression, a compressibility that allows embossed intaglio printing and good tear resistance primed.

The technique of intaglio printing is well known in the state of the art, especially for the printing of valuable papers such as banknotes, checks and other similar documents.

According to this technique, a printing plate is etched to form a predetermined pattern and the etchings, which correspond to hollows, are then filled with ink which will be carried on the printing medium, which is deformed by pressure, by means of a cylinder for example.

The surface of the paper that penetrates the engravings is thus marked with the ink that has been deposited previously in them.

US Pat. Nos. 5,062,359 and 5,899,145 describe examples of intaglio printing machines.

There are also banknotes made of plastic. They have the advantage of greater durability than paper banknotes, thanks in particular to their impermeability, their resistance to moisture, grease or other agents that can accelerate the aging of banknotes, and a better resistance to soiling. . These substrates are for the most part transparent and therefore require a step of applying an opacifying ink prior to printing.

Australian patent application AU 488,652 discloses a security carrier for making banknotes comprising a substrate of an opaque thermoplastic material bonded to a fabric or nonwoven, particularly a polyamide mesh, contributing to the three-dimensional stability. The substrate is printed and has optically variable security elements. International application WO99 / 54148 proposes a substrate consisting of an oriented polypropylene layer covered on both sides with a layer of high density polyethylene (HDPE) which has areas of weakness.

International application WO96 / 00146 teaches laminating two layers of mono-oriented HDPE so that the orientations of the two layers are perpendicular.

International application WO99 / 67093 discloses a security document composed of a plurality of polymer layers laminated between them and at least one metal layer. At least one of the polymer layers is bi-oriented and at least one other is an opaque film having cavities having areas of reduced thickness.

The fully synthetic substrates, and especially plastics, currently used have several disadvantages.

A first disadvantage is that they are not really suitable for intaglio printing which involves high pressures. In particular, these substrates are generally not compressible and intaglio print rendering on such substrates will be poor. In particular, intaglio printing on such substrates lacks tactility, forcing suppliers of such substrates to set up devices to mimic tactility, in particular by overprinting invisible marks in relief. However, the intaglio printing process is widely used in the field of secure documents including banknotes.

A second drawback is that the plastic substrates generally have a lower initial tear strength than that of a paper substrate.

A third disadvantage of plastic substrates is that the holding of the prints often degrades rather quickly, most often by abrasion effect on the salient areas resulting from folds or wrinkles, during the handling of the document.

As a result, even if the current secure plastic documents have a relatively long life compared to secure paper documents, especially with regard to the resistance to soiling, this advantage is limited because other characteristics, such as the holding of the printing, degrade quickly and that in the event of beginning of mechanical tear, this one spreads easily. There are also hybrid substrates comprising a fibrous core layer and two synthetic protective layers, such as those sold under the name Hybrid by Louisenthal. These substrates do not exhibit satisfactory soil resistance. Indeed, the dirt penetrates by the edges of the ticket.

The patent application FR 2 816 643 describes a safety support comprising two polyester films between which is inserted a nonwoven, composed of fibers mechanically resistant to tearing and heat. The polyester films and the nonwoven preferably comprise security elements.

Such a carrier has an even tear resistance equal to that of paper, printability characteristics compatible with intaglio printing, good durability of printing, as well as good resistance to temperature.

However, this support is of complex construction, and has a resistance to soiling sometimes insufficient due to the fibrous layer that it comprises, when the dirt penetrates the edges of the document.

The patent application FR2925864 discloses a sheet comprising a coextruded support made from at least one polymer material having a core layer and at least one skin layer, the core layer comprising microcavities. The substrate described in this application does not exhibit entirely satisfactory offset printability properties.

There is therefore a need for a substrate having both satisfactory resistance to circulation and dirt and printability properties compatible with a use in a secure document such as a banknote, including a good print rendering including intaglio, preferably with noticeable tactility, or offset.

There is also a need to improve the primed tear resistance of plastic substrates.

summary

The invention aims to meet this need and relates to a multilayer synthetic substrate comprising:

a compressible core structure comprising a non-fibrous polymeric material having two faces, and - Two non-completely opaque protective layers of a non-polyethylene material, preferably non-polyolefinic, each having an inner face and an outer face, each inner face being in contact with a corresponding face of the core structure.

The invention makes it possible to produce a substrate having a durability of printing as well as improved mechanical properties with respect to a paper sheet, without presenting the disadvantages of the usual synthetic substrates, in particular concerning the rendering of intaglio prints.

The "core structure" may be single or multilayer. The protective layer may define an outer face of the substrate, and thus confer to it its properties of printability and print fastness.

According to exemplary embodiments, the invention relates to a laminated triplex structure, with a core structure comprising a compressible thermoplastic material, in particular a material as described in the patent application FR2925864, and on both sides of that a protective layer, in particular a polyester film and preferably a printable PET film on one side.

The protective layers can be bonded to the core structure by lamination, either cold or hot, preferably using adhesive at the interface between each protective layer and the core structure. adhesive capable of defining the outer faces of the core structure prior to assembly with the protective layers. Advantageously, the adhesive is heat-activated, in which case the lamination is preceded by an activation step by heating.

The heat-activatable adhesive is, for example, an aqueous adhesive comprising polyurethane such as those marketed by the company DSM NeoResins.

The adhesive defines the interfaces between the core structure and the protective layers.

The invention also relates to a secure document comprising a substrate according to the invention, as defined above, and in particular a secure document constituting a means of payment such as a bank note, a check or a restaurant ticket, a identity document such as an identity card, a visa, a passport, or a driving license, a lottery ticket, a ticket, a ticket to cultural or sports events, a card to play or a card to collect. The subject of the invention is also a process for manufacturing a substrate according to the invention, as defined above, comprising the assembly of a compressible core structure, comprising a non-fibrous polymeric material, having two faces, with two non-completely opaque protective layers comprising a non-polyethylene material, preferably non-polyolefinic, each having an inner face and an outer face, each inner face being intended to come into contact with a corresponding face of the core structure. The method may comprise a step consisting in dispersing in a protective layer material at least one matting agent, for example selected from silicas, and in particular silicas of the Syloid range marketed by Grace, in particular silica Syloid ED2. The method may further comprise the embossing or compression, particularly hot, of the substrate, so as to create at least one pseudo-watermark.

According to a preferred variant, the protective layers are covered with a coating. This coating may be a resin comprising the matting agent described above and / or a crosslinking agent.

The invention further relates to a substrate according to the invention, as defined above, having undergone intaglio printing.

Heart structure

The heart structure can be opaque.

The core structure may comprise a plurality of various layers, in particular layers comprising a non-fibrous polymeric material and possibly layers of adhesive ensuring the cohesion of these layers.

In a preferred embodiment of the invention, the core structure comprises at least one core having voids. Advantageously, this core is compressible and / or deformable.

Preferably, the core structure may comprise at least one, preferably two, layer (s) of skin. Where appropriate, the two skin layers are disposed on the outer faces of the core.

The soul and the skin layer (s) can be coextruded. Alternatively, the cohesion of the skin layers is ensured by lamination, for example by means of an adhesive.

The core structure is preferably bi-stretched. Preferably, the core structure consists of a Polyart ^® film as described in FR2925864.

In particular, the core structure may be a multilayer structure having a micro-cavitary core and two layers of skin.

Preferably, the non-fibrous material of the core structure comprises high density polyethylene.

Preferably, the core structure comprises microcavities, which may be at the origin of its good compressibility.

The compressibility of the core structure gives the substrate its ability to emboss and / or compress.

Having a core structure with significant compressibility provides good intaglio print renditions, and is favorable to any other treatment generating a tactile effect.

The core structure may have micro-perforations.

The core structure may have a pseudo-watermark, this pseudo-watermark may be obtained by embossing and / or compression as described in the application WO2011 / 077403.

The core structure may be provided with at least one through recess, so that the substrate has at least one window. Indeed, the protective layers are preferably transparent. The recess or recesses are for example made by punch or by means of a laser before lamination of the core structure with the protective layers.

This recess may include an insert.

This attachment may be a security element, including a secure paper for example watermarked, a patch, a security thread, a foil, printing, an electronic chip, a wire antenna or any other element requiring thickness compensation.

The substrate may have a zone of maximum fragility vis-à-vis a delamination attempt not located at an interface between two layers, particularly at the level of the core structure. This property allows the substrate, in case of attempted delamination, that one of the layers is destroyed before the interface fails. The substrate preferably comprises at least one security element, in particular as defined below, introduced into the core structure.

The core structure may carry an impression on one of its faces, including offset printing. This impression may have been made before the core structure was joined to the layers of protection. This makes it possible, for example, to protect the printing of the risks of abrasion on the ridges formed by the folding or creasing that is usually encountered on traditional polymer or hybrid tickets.

The heart structure may have a cavity and an insert within this cavity. This cavity is for example created by local compression of the core structure, and the substrate then has no extra thickness at the insert. The insert may be in the form of a strip, in particular extending from one edge to another of the substrate.

This cavity may be present before application of the insert or alternatively result from the application of this insert, or alternatively result from the lamination of the core structure with the protective layers.

The substrate may comprise an aqueous thermoactivatable adhesive, in particular comprising polyurethane. This glue can be an integral part of the heart structure.

The core structure may be non-metallized.

The core structure preferably has, taken alone, a basis weight of between 50 and 130 g / m ² , preferably 60 and 100 g / m ² .

Preferably, the core structure is less than or equal to

130μιη.

Protective layers

The protective layers according to the invention are not completely opaque, better transparent. Thus the protective layers do not advantageously change the appearance of the core structure, while giving the finished substrate an interesting protection and an increased printability property. The protective layers preferably each have a thickness between 1 and 10 μπι, better between 4 and 8 μπι, even better between 5 and 7 μιη and in particular of the order of 6 μιη.

The protective layers are polymeric, non-polyethylene, preferably non-polyolefinic, the protective layers comprise for example PET.

The two protective layers may be identical or alternatively may be different. In particular, the two protective layers may be composed of the same materials but differ in their thickness. As a variant, one of the protective layers has a different formulation and / or a coating which makes it possible to confer distinct optical and / or printability properties on the front and back of a substrate according to the invention.

The protective layers may comprise a matting agent, especially in order to give them better printing properties.

The matting agent may be uniformly distributed in the protective layers or, alternatively, only on a part of the layers, especially close to the surface of the substrate.

The matting agent may be present in the protective layers in the form of patterns.

The matting agent may consist of nanometric and / or micrometric fillers dispersed in the protective layers, such as silica, in particular colloidal silica, titanium dioxide, calcium carbonate, barium sulfate and lithium oxide. zinc.

Preferably, the matting agent is a silica, and in particular a silica from the Syloid range marketed by Grace, in particular silica Syloid ED2.

The protective layers may, for example, be constituted by a 6μπι thick polyester film for which the presence of a siliceous matting agent makes it possible to develop a matt appearance and good drying ability of the inks.

Adhesive

A substrate according to the invention may have one or more layers of adhesive, in particular in order to ensure the cohesion of the internal layers of the core structure if appropriate, or to ensure the cohesion of the protective layers with the structure of the core. heart. The adhesive layers can be an integral part of the core structure and in particular define the outer faces of the core structure.

Before lamination of the core structure with the protective layers, the adhesive may already be present on the core structure and the protective layers may be free of adhesive. Alternatively, before lamination, the adhesive may be present on the protective layers and possibly also on the core structure, in which case the faces which delimit the core structure of the final substrate correspond to the interface between the protective layers. and the adhesive

The adhesive can be heat-activatable, heat-sealable, pressure-sensitive. It can be single-component or two-component. It can be formulated in a solvent or aqueous medium.

Preferably it is a heat-activatable adhesive, for example an aqueous adhesive comprising polyurethane such as those sold by the company DSM NeoResins. Preferably, the activation temperature of the heat-activatable adhesive does not exceed 75 ° C.

Coating

According to a preferred variant, the protective layers are covered with a coating. This coating may be a resin comprising the matting agent described above and preferably comprising a crosslinking agent.

The matting agent may consist of nanometric and / or micrometric charges

The matting agent is for example chosen from silicas, and in particular silicas from the Syloid range marketed by the company Grace, in particular silica Syloid ED2.

A siliceous matting agent makes it possible in particular to develop a matt appearance and good drying ability of the inks.

The substrate may have a coating layer on each of the protective layers.

The two coating layers may be the same or alternatively may be different. In particular, the two coating layers may be composed of the same materials but differ in their thickness. Alternatively, one of the layers of coating has a different formulation to confer distinct optical properties on the front and back of a substrate according to the invention.

As a variant, the coating is such as that described in applications EP0514455 and EP1319104.

Preferably, the coating is a resin comprising polyester, an acrylate, preferably methacrylate or nitrocellulose, or mixtures thereof, in particular in a solvent medium, for example containing a crosslinking agent of the isocyanate family and / or the matting agent. Syloid ED 2 silica base.

The coating may be applied by coating, coating or printing, especially in gravure printing.

The coating may be applied only partially to the protective layers, especially in the form of patterns.

The coating may be monolayer or multilayer.

Alternatively, two layers of coating can be superimposed, these two layers being of different composition. Advantageously, the two layers have different aspects and are applied only partially so as to create patterns.

Varnish

The substrate according to the invention may comprise an outer layer of varnish, for example an anti-fouling varnish, preferably a UV-crosslinking varnish. This varnish can be applied after printing, it is called post-printing varnish or overprint varnish.

Security elements

The substrate preferably comprises at least one additional security element.

The at least one additional security element may be dispersed in the mass of the core structure and / or at least one of the protective layers. They can still be located at the interface between the core structure and a protective layer, in particular embedded in an adhesive layer. They can still be dispersed in the mass of the coating covering a protective layer.

In a variant, the additional security elements are reported elements as described above. In particular, they are housed in a recess through or in a cavity within the core structure, said cavity having been created by local compression and / or by a recess of the core structure. The additional safety element or elements can be carried by a supporting structure, such as a thermoplastic strip, a specific binder, or even a security paper. The carrier structure may be integrated into the substrate at the time of manufacture of the core structure or, alternatively, be reported a posteriori, for example before lamination of the core structure with the protective layers.

According to one variant, the multilayer synthetic substrate according to the invention comprises at least two security elements. These security elements can cooperate optically, it is in particular:

of two elementary safety elements forming by superposition or juxtaposition, in observation in reflected light and / or in transmitted light, a combined safety element and / or

two security elements arranged in separate layers of the multilayer synthetic substrate.

The substrate or the core structure may be embossed and / or compressed, particularly hot, so as to obtain an additional security element such as a pseudo-watermark. Such methods are described in particular in application WO2011 / 077403. In particular, compression provides localized transparency and multi-tone effects. In the case where the core structure comprises coloring agents, the compression can also make it possible to obtain more saturated hues. The embossing allows in particular to provide a relief to the substrate and thus tactile characteristics. In a preferred embodiment of the invention, the additional security element or elements are carried by a strip of a thermoplastic film, in particular a PET strip, extending from one edge to another of the substrate. The band is for example received in a cavity created by local compression of the core structure, the substrate having no excess thickness at the strip. Such a band can be provided with a wide variety of security elements, and thus have a relatively high level of security.

Among the additional security features, some are detectable to the eye, daylight or artificial light, without the use of a particular device. These security elements comprise for example colored fibers or boards. These security elements are called first level.

Other types of additional security elements are detectable only with a relatively simple apparatus, such as a lamp emitting in the ultraviolet (UV) or infrared (IR). These security elements comprise for example fibers, boards or particles. These security elements may be visible to the naked eye or not, being for example luminescent under a lighting of a Wood lamp emitting at a wavelength of 365 nm. These security elements are said to be second level.

Other types of additional security elements require for their detection a more sophisticated detection device. These security elements are for example capable of generating a specific signal when they are subjected, simultaneously or not, to one or more external excitation sources. The automatic detection of the signal makes it possible to authenticate, if necessary, the document. These security elements comprise, for example, tracers in the form of active materials, particles or fibers capable of generating a specific signal when these tracers are subjected to optronic, electrical, magnetic or electromagnetic excitation. These security elements are said to be third level.

The additional security element (s) present within the substrate according to the invention or the secure document according to the invention may have first, second or third level security features.

properties

Preferably, the substrate has a basis weight of between 80 and 150 g / m ² , more preferably between 90 and 120 g / m ² .

Preferably, the substrate is less than or equal to 130μπι.

Preferably, the substrate has a shopper double-fold strength greater than 10,000, more preferably greater than 15,000.

The invention will be better understood on reading the detailed description which follows, examples of non-limiting implementation thereof, and on examining the appended drawing, in which:

FIG. 1 is a front view of an example of a secure document according to the invention, FIG. 2 is a diagrammatic section along II-II of FIG. 1,

FIG. 3 is a schematic section along III-III of FIG. 1,

FIG. 4 is a diagrammatic section along IV-IV of FIG. 1,

FIG. 5 is a diagrammatic sectional representation of a substrate according to an alternative embodiment of the invention, and

FIG. 6 is a diagrammatic section of an alternative multilayer synthetic substrate according to the invention.

In the drawing, the exact proportions of the different constituent elements have not always been respected for the sake of clarity of representation. In the same way, certain elements could be represented in contact whereas they are not in reality.

There is shown in Figure 1 a secure document 1 according to the invention which is for example a bank note. The document comprises a multilayer substrate according to the invention, which comprises a core structure 10 and two protective layers 12.

The core structure 10 may be monolayer or alternatively multilayer. In particular, the core structure 10 may comprise, as can be seen in FIG. 2 in particular, a central or core layer 103, two peripheral layers or skin layers 104, and two adhesive layers 105.

The core structure 10 is compressible and comprises a polymeric material which can constitute the central layer 103 and which can have an intrinsic compressibility and / or compressibility conferred by structural features, such as microcavities 101, capable of collapsing during sufficient compression of the substrate.

The amount of microcavities is adjustable during the manufacture of the substrate, which makes it possible to vary the hand of the substrate according to the invention without modifying its structure.

The core structure advantageously has a white base color, compatible with a ticket application, a perfectly flat and non-porous surface state which, unlike a paper substrate with a rougher roughness and with non-zero porosity, requires a quantity less adhesive when laminating at equal adhesion performance.

The core structure and the protective layers are hydrophobic and impervious to liquids, which ensures the inertia of the substrate vis-à-vis liquids. The quality of the surface condition of the core structure and the protective layers is a advantage in view of the delamination resistance of the substrate as it allows uniform spreading of the adhesive layer at the core structure / protective layer interfaces.

It is also possible to play on the destructurability of the core structure in order to generate more fragility within the core structure 10 than at its interface with the protective layers, and thus to promote resistance to the structure of the core. counterfeiting and falsification by delamination.

The core structure is for example made of a Polyart ^® film, and has a thickness e _c less than or equal to 130 μπι.

The core structure may optionally include micro-perforations 102, as illustrated in FIG. 5.

The secure document 1 may include an intaglio print 19, the tactile rendering of which is improved by the increased compressibility of the core structure 10. The flexibility of the core structure minimizes the crease marking of the substrate and limits surface abrasion effects at the folds. The durability of prints, especially intaglio and offset, is improved due to the flexibility of the core structure and the formulation of the protective layers.

The protective layers 12 consist of a non-polyethylene material, preferably non-polyolefinic, especially a polyester, and preferably PET.

The protective layers 12 are preferably completely transparent or translucent but may have opaque areas locally. They preferably have a thickness e _p of between 1 and 10 μπι. The protective layers may consist of transparent PET films 6 μπι thick. Advantageously, the protective layers comprise an adhesion primer.

The protective layers 12 may comprise a matting agent 121.

A protective layer may comprise a plurality of coextruded sub-layers, the outermost sub-layer comprising the matting agent 121, as illustrated in FIG. 4. Alternatively, the matting agent is dispersed in the mass of the protective layer 12, as illustrated in FIGS. 2 and 3. The dispersion can be carried out homogeneously but, preferably, it is carried out in a heterogeneous manner so that the matting agent 121 is concentrated near the outer face of the protective layer 12. The agent Matifying 121 is for example a silica, in particular a Syloid ED2 silica sold by Grace.

The secure document 1 may also include a window 106, as shown in FIG. 4. This window 106 can be made by means of a recess passing through the core structure 10, for example made with a punch, before laminating the core structure. 10 with the protective layers 12 not completely opaque.

The window 104 may be exploited to display additional securities, such as reported security elements. Two impressions 1040 can each be made on a protective layer 12 to form a complementary pattern, as shown in FIG. 4.

The secure document 1 may comprise, within its core structure 10, security elements 15 of second or third level. In particular, it is advantageous to affix the safety elements sensitive to abrasion, thin in order to protect them by the protective layers of the risks of mechanical degradation by abrasion and counterfeiting. These sensitive elements may be chosen from foils or holographic, metallic or iridescent patches.

The core structure 10 may have a printing layer, not shown, for preprinting the core structure completely or partially before the application of the protective layers, in particular to protect the printing of the risk of abrasion on ridges formed by folding or wrinkling of the substrate.

Advantageously, the printing operation, in particular the offset printing or the printing of security inks to be protected, is carried out before the complexing of the substrate. In the case of a complexing operation, it is possible to carry out the printing operation after the protective layers have been applied in order to avoid masking the tactility of intaglio printing.

Advantageously, security elements are incorporated in the core structure before lamination and are thus protected by the protective layers.

The substrate may advantageously be the subject of a hot embossing operation, making it possible to create a pseudo-watermark because of the compressibility of the core structure and the translucent appearance obtained by compression.

One or more additional security elements 17 may be added to the substrate, and for example integrated within a strip of a thermoplastic film 170, in particular a PET strip, received in a cavity 171 created by local compression of the core structure before or during the complexing, as illustrated in FIG.

In this configuration, the compression of the core structure 10 makes it possible to compensate for the thickness of the added strip and to guard against any excess thickness.

It is possible to produce a low-weight watermark paper 16, possibly secured by the addition of security elements, such as visible or invisible fluorescent security fibers.

The paper 16 may be a standard composition paper or a synthetic paper.

This paper can be surfaced to exhibit hydrophobic properties, and coated on at least one of its faces with an adhesive 161, for example a heat-sealing adhesive. The paper 16 is for example cut into strips; alternatively the paper 16 is pre-cut with a punch.

The paper 16 is then transferred to the core structure 10, within a cavity

160 created by local compression.

Alternatively, a filigree patch is affixed by a transfer machine.

The core structure 10 can accommodate any paper carrying a conventional watermark. The compression of the core structure 10 makes it possible to avoid or limit an excess thickness in the watermark. The subsequent application of the printable protective layers 12 makes it possible to protect the watermark.

A preferred structure of the multilayer synthetic substrate according to the invention is shown in FIG.

The core structure 10 comprises a core 103 and two skin layers 104, for example a Polyart sheet.

The substrate further comprises two protective layers 12 adhered to the core structure 10 by means of adhesive layers 105 present on the surface thereof. These protective layers 12 are covered externally with a coating 13 comprising a matting agent 121.

This structure may comprise security elements, cavities, as well as through recesses as previously described, in particular in FIGS. 1 to 5. Comparative examples

A substrate according to the invention is produced by complexing a Polyart® sheet with two 6μιη-thick PET films by means of a NeoRez R563 heat-activatable adhesive. The PET films are coated with a coating comprising a mattifying agent based on silica Syloid ED2. For comparison, two existing substrates are used. The first is a hybrid substrate formed of a paper coated on both sides with a PET film, this substrate differing from the substrate according to the invention only by the composition of the "core structure". The second is a plastic ticket made according to the publication WO93 / 00659. The results of these tests are recorded in the tables below.

Substrate according

Hybrid substrate Plastic ticket the invention

Weight g / m ² 109.7 108.3 86.0

Thickness μηι 125 128 91 mass volume cm ³ / g 1, 14 1, 18 1, 06

Opacity bottom paper 86.1 93.7 -

Tensile strength at

% 75.4 99.1 - the wet state

Meaning of the meaning

SM Transverse Walk ST SM ST (SM) (ST)

Rigidity Taber 2.2 1, 3 1, 9 2.0 0.7 0.6

Tear resistance mN 819 954 599 81 1 252 252 double-

Folding SHOPPER 5948> 15000> 15000

folds

Holding the prints RECTO VERSO RECTO VERSO RECTO VERSO

Abrasion resistance

2.5 2.5 3.5 3.0 to 3.5 3.0 3.0 printed inks

RECTO VERSO RECTO VERSO RECTO BACK

Resistance to soiling

Index 1, 2.0 0.9 0.87 0.77

Wet soiling

Average 1, 05 0.81

Dry soiling: 16.90 18.00 19.12 18.61

Δ E average 2 sides 17.5 18.9

The following standards were used:

Measured weight according to ISO 536 "Paper and board - Determination of grammage",

Thickness measured according to ISO 534 "Paper and board - Determination of thickness, density and specific volume",

Wet strength (%) = 100 x wet break length (ISO 3781) / dry break length (ISO 1924-2)

Double-fold resistance (or Schopper folding) measured according to ISO 5626 "Paper; determination of the folding resistance » Tear resistance measured according to ISO 1974 "Paper - Determination of tear strength - Elmendorf method"

Opacity measured according to NF ISO 2471

Tabber rigidity measured according to ISO 2493

Moist soil resistance test

We realize:

an artificial sweat composition A:

Distilled water: 500g

NaCl: 5 g

Lactic acid: 5 g

Urea: 0.5 g

Histidine hydrochloride: 0.5 g

Water: qs 1000 g a powdery colored composition B:

Bayferrox 420 from LANXESS (BAYER): 0.833 g

Bayferrox 610 from LANXESS (BAYER): 0.833 g

Micronite black C-K from BASF (CIBA): 0.083 g

2D vermiculite from EFISOL: 248.25 g

These compounds are mixed using a TURBULA mixer for 30 minutes in a plastic bottle with six large ceramic balls,

a fat composition C:

We start from a mixture:

Lanolin Lanor TEC from the company LANOLINES DE LA TOSSEE:

200 g

Disponil TD 0785 from NOPCO: 20 g

Homogenize until the lanolin melts. 28 g of water are added with stirring, followed by 16 g of Eumulgin BA 10 from NOPCO, and the mixture is heated until a homogeneous preparation is obtained. It is allowed to cool to room temperature, and 24 g of water are added, mixing for 15 minutes. Then another 190 g of water is added, very slowly at first. An emulsion with 42% lanolin is obtained. Each sample is creased beforehand 4 times manually with the crimping device IGT.

The samples (75 mm x 140 mm) are mounted on wooden blocks (60 x 35 x 35 mm), around which the samples are held with three exposed faces.

20 g of fat composition, 10 g of powdery colored composition and 90 ml of artificial sweat composition and 25 ceramic beads having a diameter of 20 mm or less are placed in a plastic jar of 2L. The four wooden blocks, dry, on which the samples have been placed, are then stirred and introduced.

The jar is closed and stirred in the TURBULA mixer at 67 rpm for 20 minutes.

The samples are then rinsed under running water and then dried using two blotters and then oven-dried at 60 ° C. for 3 minutes.

The samples are then ironed between two blotters in the 2/3 position.

The samples are calendered one by one with one passage per side, at 15 bar pressure, minimum speed.

The IS foul index is then evaluated:

_ {B ₁ -B ₀ ) + {J ₁ - J ₀ )

2

where B1 is the whiteness measured on the samples after the test, B0 is the whiteness before the test, Jl is the degree of yellowing after the test and J0 is the degree of yellowing before the test. The whiteness is an average value of three measurements according to the NF ISO 2470-2 6167 standard and the degree of yellowness is an average value of three measurements (measurement with the DATACOLOR ELREPHO 3000 device from the company LORENTZEN & WETTRE common in the paper industry ).

The alumina balls must not weigh less than 300 g. They are packaged before use by placing them in the TURBULA machine with an abrasive cream and a little water for 1.5 hours.

Abrasion resistance of printed inks

Artificial sweat composition: A whose formula is given above. Abrasive composition: Vermiculite 2D from EFISOL.

Fat composition: Same formula as C above. Samples are printed with SICPA blue S12W ink which was allowed to polymerize for 8 days prior to the test, with the impression being intaglio.

The samples are 75 x 140 mm strips.

20 g of fat composition, 10 g of abrasive composition and 90 ml of artificial sweat and 25 ceramic beads with a maximum diameter of 20 mm are placed in a plastic bottle 21.

After crumpling the samples are mounted on four wooden wedges as in the previous test.

The assembly is rotated for 20 minutes at 67 rpm.

The rinsing and drying of the samples are carried out as described in the previous test.

The results are evaluated with a visual scale ranging from 1 to 5 (1 severely degraded sample, 5 no deterioration).

Dry dirt resistance test

Equipment

Turbula mixer

Two-liter plastic bottle (H: 23 cm Diameter: 11 cm)

Teflon weight with male and female thread

Plastic reinforcements

500 g of glass beads (2.5 mm in diameter)

Punch

Elrepho L & W 070 colorimeter

Composition of the soil mixture

Mix of vermiculite

90g of 2D Vermiculite from EFISOL

30g of sand

15g of Bayferrox 420 from LANXESS (BAYER)

12g of Bayferrox 610 from the company LANXESS (BAYER)

Colorful olive oil

50 g of olive oil 2g of chlorophyll Paste OF 0032 from Naturex

Preparation of test pieces

Cut the ticket-size test pieces (SM in the short direction) Make a hole at each corner about 10 mm from each angle Weigh each test piece

Place the plastic supports in the short direction of the test tubes

Fix them with Teflon weights and tighten tightly

Preparation of the soil mixture

Put in the plastic bottle

1 g of vermiculite mixture

1 g of colored oil

500 g of glass beads

Shake briefly

Procedure

Add 4 samples to the vial

Rotate at 67 rpm for 10 minutes in the Turbula machine

Take out the samples, remove the Teflon weights and the supports

Thoroughly wipe each specimen several times per face with a rag until all loose dirt is removed

Let condition two hours at 50% humidity and 23 ° C

Measure the Delta E by first measuring the color of a control sample from the same sheet and then measuring the color of the test piece tested

Calculate weight gain in percentage

Then carry out the evaluation by calculating the color difference ΔΕ ^* (Elrepho measurement USAV395 white plate in CIE L * a * b * color space under D65 illuminant and 10 ° observation, according to F EN ISO 11664 standard -4) from the measurements on the samples before and after the test.

The measurements are taken at five locations of the test pieces. Expression of results

The level of soiling is determined by Delta E measurement and weight gain

The example of the substrate according to the invention is in a weight and thickness range close to that of the hybrid substrate with a thickness of less than 130 μπι and a basis weight of less than 110 g / m ² . It is a more opaque substrate, despite the low basis weight of the heart structure.

The folding resistance is very high, higher than 15000 double folds on average. The level of wet strength is excellent. The tear resistance is less primitive compared to the hybrid substrate but remains much higher than the plastic ticket.

The resistance of the prints is very interesting. Due to the presence of a flexible core structure, the behavior of the Yink wear test substrate is very satisfactory and the ink abrasion on crease-generated edges is significantly reduced.

A substrate according to the invention can have a rigidity three times greater than that of the polymer substrates on the market while having a thickness comparable to a conventional paper. The use of these substrates within banknotes does not require any modification of the automatic bill processing equipment.

The substrate according to the invention may also have an appearance, a touch, and a foil very close to a cotton banknote. The substrate may further have good intaglio printability, tear resistance initiated twice as high as the hybrid substrate, superior ink abrasion resistance, which is remarkable for a synthetic material.

The expression "having one" shall be understood as being synonymous with "having at least one", unless the opposite is specified.

Claims

Multilayer Synthetic Substrate for Banknote, comprising:

a compressible core structure (10) comprising a non-fibrous polymeric material having two faces, and

two non-completely opaque protective layers (12) made of a non-polyethylene material, each having an inner face and an outer face, each inner face being in contact with a corresponding face of the core structure.

2. Substrate according to claim 1, the non-fibrous material of the core structure comprising high density polyethylene.

3. Substrate according to one of claims 1 and 2, the core structure comprising micro-cavities.

4. Substrate according to any one of the preceding claims, the protective layers each having a thickness between 1 and 10 μπι, better between 4 and 8 μπι, even better between 5 and 7 μπι, in particular of the order of 6 μπι .

5. Substrate according to any one of the preceding claims, at least one of the protective layers being covered with a coating.

Substrate according to any one of the preceding claims, the core structure (10) being provided with at least one through recess (106).

Substrate according to any one of the preceding claims, the protective layers (12) comprising PET.

8. Substrate according to any one of the preceding claims, having a zone of maximum fragility vis-à-vis a delamination attempt, not located at an interface between two layers.

9. Substrate according to any one of the preceding claims, comprising at least one security element.

10. Substrate according to any one of the preceding claims, the core structure bearing an impression on one of its faces, in particular an offset printing.

The substrate of any preceding claim, the core structure having a cavity (160) and an insert (16) within that cavity.

12. Substrate according to the preceding claim, the cavity being created by local compression of the core structure, the substrate having no extra thickness at the insert.

13. Substrate according to one of claims 11 and 12, the added element being in strip form, in particular extending from one edge to another of the substrate.

Substrate according to any one of the preceding claims, wherein the protective layers comprise at least one matting agent, this matting agent being preferably chosen from micrometric or nanometric dispersed fillers, such as silica, titanium dioxide, calcium carbonate, barium sulfate and zinc oxide, preferably a colloidal silica.

Substrate according to any one of the preceding claims, comprising a heat-activatable adhesive (105)

16. Substrate according to any one of the preceding claims, comprising at least one additional security element, the additional security element or elements being preferably carried by a strip of a thermoplastic film, in particular a PET strip, extending from one edge to another of the substrate.

17. Substrate according to the preceding claim, the band being received in a cavity (171) created by local compression of the core structure, the substrate having no excess thickness at the strip.

18. Substrate according to any one of the preceding claims, having undergone intaglio printing.

Substrate according to any one of the preceding claims, the core structure (10) being unmetallized.

20. Substrate according to any one of the preceding claims, the core structure comprising at least one layer of skin, the core structure preferably comprising two skin layers.

21. Substrate according to any one of the preceding claims, the substrate being of thickness less than or equal to 130μιη.

22. Bank note comprising a substrate (1) according to any one of the preceding claims.

23. A method of manufacturing a substrate according to any one of claims 1 to 21, comprising assembling a compressible core structure (10), comprising a non-fibrous polymeric material (103), having two faces, with two non-completely opaque protective layers (12), comprising a non-polyethylene material, each having an inner face and an outer face, each inner face being in contact with a corresponding face of the core structure.

24. The manufacturing method according to the preceding claim, comprising hot embossing the substrate so as to create at least one pseudo-watermark.