KR20170140209A - Paper containing synthetic fibers - Google Patents

Abstract

[0001] The present invention relates to a paper, comprising finely divided synthetic fibers; And mixtures of non-micronized synthetic fibers having different shape factors in cross-section, especially mixtures of non-micronized synthetic fibers of circular cross-section and flat cross-section.

Description

Paper containing synthetic fibers

The present invention relates to fiber documents, in particular, security documents.

More particularly, the present invention relates to a paper suitable for making secure documents and a manufacturing method thereof, but is not limited thereto.

A "security document" may include, for example, security documents such as banknotes, checks, bank cards or restaurant vouchers or valuable documents such as identification documents, visas, passports, Inlay "or identity document such as a vehicle license, lottery ticket, travel ticket or admission ticket for cultural or sporting events.

It is known to add to the substrate of a document, for example, a fiber, strip, knitted structure, or hidden line security element to protect the security document against attempts to counterfeit or tamper. The description of the document is referred to as a "security base" because it can be composed of materials that make it difficult to imitate itself.

Since the lifetime of secure documents is generally limited, "very high endurance" security disclosures are being developed.

In the field of security substrates in the form of sheets, so-called "composite" substrates, such as cellulose substrates, plastic substrates, and so-called "hybrid" substrates, are known.

Cellulose substrates are fiber substrates which are generally obtained by the so-called wet process from the cellulose fibers, such as fibers from hardwoods, conifers, annuals, especially cotton, or mixtures thereof.

The "papermaking process" or "wet process ", as described above, may be used in particular for the discharge of fiber suspension, which may be pre-refined and optionally includes fillers and additives used in conventional papermaking processes and / step; Pressing the obtained wet sheet; And a drying step. The term " paper "

The so-called "composite" substrates are cellulose substrates whose fiber components comprise synthetic fibers in addition to the cellulosic fibers. Such fibers are generally introduced at levels below 20% dry weight based on the total weight of the substrate, and their use may increase the mechanical strength of the substrate.

The presence of cellulose fibers plays an important role in the entanglement and fixation of synthetic fibers and can improve the inherent potential of synthetic fibers. In fact, in improving the mechanical properties of sheet materials, the ability of the polymers of the synthetic fibers is important, but the ability to interact with the fibers is also crucial. The presence of the refined cellulose fibers significantly promotes the bridging bonds between the cellulose and the polymer of the synthetic fibers.

Composite substrates give better resistance to circulation than cellulose substrates. The expression "resistance to distribution" means a combination of properties such as folding resistance, tearing resistance, and soiling resistance.

So-called "hybrid" substrates have at least one cellulose or composite substrate associated with at least one plastic substrate. With respect to the cellulose or composite substrate they comprise, they generally exhibit equivalent tear resistance and improved fold resistance.

Hybrid substrates used in the field of security substrates are disclosed in applications WO 2006/066431, WO 2004/028825, EP 1 854 641, WO 03/054297 and WO 94/29105.

Plastic substrates are generally obtained by compression of the polymer. These substrates usually have "very high durability ".

These plastic substrates are disclosed in applications EP 2 225 102, WO 99/67093, WO 97/01438, and WO 83/00659. These substrates exhibit good folding and tearing resistance, but their tear spreading resistance is relatively low.

Also, as described in, for example, the applications EP 0 059 056, GB 2 388 377 and GB 2 381 539, these substrates may be formed from at least partly watermarked in the bulk, Or hybrid), it is difficult to make them secure.

There are also so-called nonwoven substrates. Nonwoven substrates are defined as sheets made in the standards ISO 9092 and EN 29092 and are composed of layers of films or fibers which are oriented or randomly oriented and are joined by friction and / or cohesive and / or adhesive forces, Products obtained by weaving, knitting, tufting or stitching are excluded and are integrated with felt by tying threads or filament or wet fulling, irrespective of their stitching treatment. do.

The Nonwoven Fabrics Industry Association (INDA) defines them as "sheets or films of natural fibers and / or manufactured fibers or filaments that can be bound together in a variety of ways without being woven, but woven."

These materials and their manufacture are different from the "Les non-tissues" (Gerard Coste, June 25, 2004) and "Material Science & Engineering 554-Nonwoven science and technology II "(Larry C. Wardsworth, 2004. spring).

- http://cerig.efpg.inpg.fr/tutoriel/non-tisse/summary.htm and

- http://web.utk.edu/~mse/Textiles/index.html.

In WO 2002/38368 and FR 2 447 995, nonwovens are described as useful as security articles. These substrates are typically composed of non-cellulose long fibers, for example, having a length of 3 mm to 25 mm and a high bulk and porosity, meaning that the damage resistance is low.

The nonwoven fabrics can be extruded by a variety of methods, in particular by dry processes, such as, for example, by carding or aerodynamic methods (also named "Airlaid"), (Also referred to as "Wetlaid") by a process similar to the papermaking process by means of extrusion blowing (also referred to as "Spunbond") or extrusion blowing (also referred to as "Meltblown" (Also called "Flash spinning"), or by other methods, especially in solvents.

The nonwoven fabrics produced by the wet process generally include cellulose fibers to provide a better example, at least 10% cohesive strength, in the resulting substrate.

In addition, when the proportion of the cellulose fibers in the non-woven fabrics produced by the wet process is low or even zero, the hydrogen bonds formed between these fibers do not provide sufficient cohesion to the substrate and therefore it is necessary to carry out at least one bonding step . Such bonding can be effected by impregnation, latex spraying or coating, by thero-fixation, by stitching or by water jet binding (so-called Spunlace) have.

Application EP 2 438 599 discloses an example of a nonwoven fabric substrate with or without cellulose fibers.

By introducing reinforcing fibers into the paper bulk, the mechanical properties of the paper can be further improved. These reinforcing fibers are generally introduced at a rate of dry weight of greater than 3% relative to the total dry weight of the fibers of the paper and are generally polyamide 6.6 (PA 6.6) or polyethylene (polyethylene terephthalate) due to the mechanical strengths and economic reasons exhibited by these polymers. Based on synthetic polymers such as terephthalate (PET). These reasons relate to the preparation and good interaction of the cellulose fibers of the paper.

"Synthetic fibers" should be understood as fibers made using one or more synthetic polymers, through chemical synthesis, whether or not linked to a cross-linking reaction, especially where polymers are obtained by polymerization of monomers.

Preferably, the nonfibrillated synthetic fibers have a number-average length of from 0.5 mm to 8 mm, preferably from 4 mm to 6.5 mm.

The following Table 1 shows the extent of the tear resistance and folding resistance of the above described substrates.

The tear resistance is determined by the standard ISO 1974 "Determination of the paper-tear resistance - Elmendorf method" and the folding resistance is in accordance with standard ISO 5626 "Determination of folding endurance".

Cellulose substrates Composite materials Hybrid substrates Plastic substrates Tear Resistance (mN) 800 1100 800 250 Folding resistance 2500 5000 > 5000 > 5000

The present invention particularly provides a novel substrate with improved tear resistance and folding resistance and improved mechanical strength properties, such as greater tear resistance than that of prior art security paper substrates and at least the same folding resistance as that of plastic substrates .

To achieve the above object, according to one aspect, a paper includes fibrillated synthetic fibers; And non-refined synthetic fibers.

In addition, this kind of paper may correspond to the major security features used in the papers, particularly the insertion of watermarks and hidden lines at least partially within the bulk.

Applicants have discovered that although micronized synthetic fibers make an important contribution to the improvement of mechanical strength properties, they have an adverse effect on bulk (water volume) and watermark rendering of the paper.

Therefore, there is a need to further improve the mechanical strength properties such as tear resistance and folding resistance, without any undue side effects on the formation of the sheet and watermark rendering.

The present invention has the purpose of satisfying this need.

To achieve this object, the paper of the present invention is characterized in that the paper comprises finely synthesized fibers, non-micronized synthetic fibers having a cross section with a first shape factor, and a section having a second shape factor greater than the first shape factor Non-refined synthetic fibers.

The presence of non-micronized synthetic fibers with different shape factors further improves the properties of the paper, as described below.

The two shape coefficients are preferably different by at least two factors: The first shape factor may be close to 1, corresponding to fibers of approximately circular cross-section. The second shape factor may be greater than 2, preferably greater than 3, more preferably greater than 5 or 10, corresponding to flat, particularly substantially rectangular cross-section fibers.

The substrate according to the present invention is a paper, which is obtained by a papermaking process, in particular, by an inclined table, a flat table and / or a cylinder mold process. For example, a cylinder mold process is preferred to obtain a better watermark resolution at least partially within the bulk and incorporate hidden lines.

Therefore, techniques conventionally used to provide security properties to papers can be used to provide security features within the disclosure in accordance with the present invention. Moreover, the substrate according to the present invention has improved properties for cellulose papers, in particular, greater tear resistance.

The invention will be better understood when the following detailed description of the non-limiting embodiments is read in conjunction with the accompanying drawings.
Fig. 1 shows a two-component basis fiber 1, so-called "pie wedge fiber ", having a segmental cross section in regions.
Figure 2 shows the two-component basis fibers 1 of the so-called "segment ribbon" cross section ("segment ribbon fibers").
Fig. 3 shows a two-component basis fiber 1 of a so-called "hollow pie wedge" cross section ("hollow pie wedge fiber").
Fig. 4 shows the two-component foundation fibers 1 of the so-called "segment cross" cross section ("segment cross fibers").
Fig. 5 shows a two-component foundation fiber 1 of so-called "tilted end triple lobe" cross section ("triangular lobe fibers"
Fig. 6 shows a so-called "conjugated"("compositefiber") two-component foundation fiber 1 whose components have a multi-layer cross-section alternating from one side of the region to the opposite side.

In the drawings, the different elements have not necessarily been referred to as being in contact with one another or in their actual proportions in order to more clearly illustrate the figures.

Mineralized synthetic fibers

Fibers are fibers with fibrils extending from the body of the fiber. In particular, the micronized fibers may be fibers that cause at least one wall to be partially broken to cause partial release of the fibrils.

Such fibers can be used to limit the ability of the fibers to slide over one another and to increase the interactions of these fibers with other fibers, particularly synthetic fibers, do. Such fibers are illustratively disclosed in FR 1 317 778 and FR 2 199 015.

Therefore, the micronized fibers play an important role by the cohesive force of the paper according to the invention, in particular by the entanglement effect.

The paper according to the present invention can be used in a wide variety of applications such as polyamide (PA), polyethylene (PE), polypropylene (PP), poly (ethylene terephthalate) (PET, also referred to as polyester), polyvinyl alcohol Such as those sold by Sterling under the reference CRR 111-2, polyesters such as polyesters (e.g., Vectran (e.g., Vectran® available from Kuraray), polyamideimides, polyolefin fibers, Mined synthetic fibers. Preferably, the material of the micronized synthetic fibers has a tensile strength of 300 MPa to 600 MPa.

In the present invention, the presence of micronized synthetic fibers compensates for the absence or less amount of cellulose fibers and provides the mechanical performance required in terms of tear resistance and folding resistance.

According to a preferred variant of the invention, the paper comprises micronized polyethylene, in particular high density polyethylene fibers. In fact, apart from their ease of application, these fibers achieve good watermark rendering. The proportion of micronized polyethylene fibers is preferably greater than 50% dry weight relative to the total dry weight of the fibers. The average length of the micronized polyethylene fibers is preferably 0.5 mm to 2 mm.

Specifically, when the fiber component of the paper has at least 20%, preferably 50%, of the dry weight of the micronized polyethylene fibers, the following are possible:

In particular, the creation of bonds by heat-sealing to strengthen the paper,

- the generation of patterns which are translucent and engraved / relieved (relief), in particular by embossing, compression and / or thermoforming, and / or

- melt at the melting point of the polypropylene to recycle the paper, and other components of the paper generally have a higher melting point than polypropylene.

Preferably, the micronized synthetic fibers have an average length of 0.5 mm to 8 mm, preferably 2 mm to 8 mm, and more preferably 4 mm to 6.5 mm.

The specific surface area of the micronized synthetic fibers according to the present invention is preferably 35 m ² / g to 75 m ² / g, and more preferably approximately 50 m ² / g. It is measured according to the standard ISO 9277 "Determination of specific surface area of solids by gas adsorption - BET method ".

Preferably, the paper according to the invention has a dry weight of at least 5%, preferably at least 10% dry weight, and more preferably at least 20% dry weight of micronized fibers relative to the total weight of the paper. As a variant, the paper according to the invention has a dry weight of at least 50% of the finely divided synthetic fibers relative to the total weight of the paper.

The finely divided synthetic fibers can be white or colored and in particular are of a color that can be the same as or different from that of other synthetic fibers.

The level of micronization of the fibers may be from 5 mL to 700 mL, preferably from 5 mL to 100 mL, according to CSF standards.

The fibers can comprise at least one tracer which can be identified by means of defined means, in particular by exposure to UV and / or IR radiation, and / or by exposure of the indicator . Therefore, such a tracer may be a fluorescent tracer under the luminescence, in particular under UV or IR.

The micronized fibers may not all have the same formulation.

Having a cross-section with a first shape factor, in particular a cross- Non-refinement  Synthetic fibers

Preferably, the shape factor of these fibers is less than 1.5, preferably less than 1.3, more preferably 1.1, corresponding to a roughly circular cross-section.

The shape factor is defined as the ratio of the maximum external dimension in the section to the minimum external dimension in the same section. Therefore, a fiber of a completely circular cross-section has the same form factor as one. Fibers with elliptical cross sections with low eccentricity can have a form factor close to one. For a rectangular section, the form factor is equal to the ratio of the width of the section to its thickness. For square cross-sections, the shape factor is equal to 2 ^1/2 .

In particular, the non-micronized synthetic fibers of the first aspect modulus of the circular cross-section are preferably selected from the group consisting of polyamide (PA), polyacrylic polypropylene (PP), poly (ethylene terephthalate) (also referred to as PET, Selected from polyvinyl alcohol (PVA), aromatic polyesters (e.g. Vectran (R) marketed by Kuraray), polyamide imides, ethylene vinyl alcohol copolymers (EVOH), polyolefins and preferably polyethylene do.

The non-micronized synthetic fibers are more preferably polyamide fibers, among other thermoplastic fibers.

The paper according to the invention preferably has a dry weight of less than 95% dry weight, preferably less than 90% dry weight, more preferably less than 95% dry weight of non-micronized synthetic fibers of the first aspect modulus, Lt; RTI ID = 0.0 > 80% < / RTI >

The amount of dry weight of non-micronized fibers of the first aspect modulus relative to the total weight of the paper is preferably at least 5%.

Preferably, the non-micronized fibers of the first aspect modulus have a number-average length of 3 mm to 6 mm and a count of 0.3 to 1.7 decitex (dtex).

Preferably, the non-micronized synthetic fibers of the first aspect modulus have a count of less than 2 dtex, preferably less than 1 dtex, and more preferably less than 0.5 dtex. Non-micronized synthetic fibers of the first type modulus are, for example, fibers sold under the name of Mini Eslon by Woongjin, which are made up of 0.3 dtex PET fibers or, for example, commercially available from Kuraray under EP 023 And 0.33 dtex of PET fibers. In particular, the unimorphized synthetic fibers of the first aspect modulus of the circular cross-section are fibers of polyamide 6.6 of 1.7 dtex 4 mm commercially available from Rhodia or fibers of poly (ethylene terephthalate) marketed by Kuraray under the reference EP023 5 mm .

Non-micronized synthetic fibers of the first aspect modulus may have the same hue as the micronized fibers or may have different hues.

Flat, in particular, with a rectangular cross section, The second type  Coefficient Non-refinement  Synthetic fibers

These fibers are preferably synthetic fibers having "flat" cross-sectional fibers, that is, a cross-section of at least 3 times, preferably at least 5 times, more preferably at least 10 times the width, Therefore, the form factor of these fibers is preferably at least 3, preferably at least 5, and more preferably at least 10.

In particular, the width of the cross section of the non-micronized synthetic fibers having a shape coefficient of at least 3, that is, a second shape coefficient, is preferably from 5 탆 to 25 탆, more preferably from 10 탆 to 20 탆.

In particular, the thickness of the cross section of the non-micronized synthetic fibers having a shape coefficient of at least 3, that is, a second shape coefficient, is preferably 0.5 탆 to 10 탆, more preferably 1 탆 to 5 탆.

Preferably, in particular, the non-micronized synthetic fibers having a shape factor of at least 3, i.e. a second shape factor, are selected from the group consisting of polyamide (PA), polyacrylic polypropylene (PP), poly (ethylene terephthalate) Polyvinyl alcohol (PVA), aromatic polyesters (e.g., Vectran® sold by Kuraray), polyamide imides, ethylene vinyl alcohol copolymers (EVOH), polyolefins and preferably polyethylene (PE). ≪ / RTI >

In particular, the non-micronized synthetic fibers having a shape factor of at least 3, that is, a second shape factor, are more preferably polyamide fibers and / or polyester fibers.

In particular, non-micronized synthetic fibers having a form factor of at least 3, i.e., a second form factor, may be prepared by mixing, for example, mixed fibers of polyester and polyamide commercially available from Kuraray under the Wramp W101 standard, For example, polyester fibers available from Teijin under the TA 14N standard.

The paper according to the invention preferably has a dry weight of at least 10%, preferably at least 15% dry weight of non-micronized synthetic fibers having a form factor of at least 3, especially at least 25% Dry weight.

The paper according to the invention preferably has a dry weight of less than 60%, preferably less than 50% of dry weight, and more preferably less than 40% of non-micronized synthetic fibers having a form factor of at least 3, % Dry weight.

Preferably, particularly, the non-micronized synthetic fibers having a form factor of at least 3 and a second form factor have a number-average length of from 2 mm to 10 mm, preferably from 3 mm to 7 mm, more preferably from 5 mm to 6 mm, .

In particular, the non-micronized synthetic fibers having a shape factor of at least 3 and a second shape factor may have the same hue or different hue as the micronized fibers.

In particular, the non-micronized synthetic fibers having a morphology factor of at least 3 and a second morphology factor are preferably obtained from a multi-component, preferably two-component primary fibers ("splittable fibers"). These basic fibers may be in the form of segmented ribbons, segmented crosses, or may have multi-lobed, in particular triploidized regions, or may have a segmented circular cross-section in the regions, or be hollow or solid . Examples of such fibers are shown in Figs. 1 to 6, which will be described later.

Referring to Figs. 1 to 6, the two-component basis fibers shown in these drawings have a first component 2 and a second component 3. They are, for example, polyester and polyamide, respectively.

Referring to Figure 1, the regions of one component alternate with those of the other components relative to the axis of the fiber. The areas are separated in the pulp, for example, during the manufacture of the paper by stirring the fibrous suspension. To permit such separation (or cleavage), the regions may be bonded together by a soluble adhesive. These types of fibers are produced by extrusion.

Preferably, the components of these foundation fibers are separated when they are used in the production of the paper according to the invention, in order to obtain non-micronized fibers having a flat shape with a second aspect modulus, in particular a shape factor of three or more.

Non-micronized synthetic fibers of rectangular cross-section are preferably obtained from two-component fibers of cross-section.

Preferably, in particular, the non-micronized synthetic fibers having a shape factor of at least 3, i.e. a second shape factor, have a count of less than 3 dtex. In particular, the non-micronized synthetic fibers having a shape factor of at least 3, i.e., a second shape factor, are, for example, fibers that are commercially available from Teijin under the TA 14N standard and are polyester fibers, dtex < / RTI > based on Wramp W101, a two-component polyester / polyamide conjugated fibers.

During dissociation, multi-component basis fibers can produce only non-micronized synthetic fibers having a form factor of three or more. As a variant, they can produce fibers with a modulus of modulus of less than 3, in particular less than 2, preferably less than 1.1 and, strictly, fibers with a modulus greater than 3. All non-micronized synthetic fibers of the present invention, which differ in their form factor, can arise from one dissociation of the same type of basic fibers. As a variant, the mixture of non-micronized synthetic fibers of different shape factors according to the invention is obtained from the introduction of fibers having a first aspect modulus, in particular of circular cross-section fibers, and of multiple components, in particular of two- Occurs.

Other fibers

The paper according to the present invention may comprise non-synthetic fibers of less than 5% dry weight, such as cellulose fibers, relative to the total weight of the paper, preferably less than 2% dry weight of the total weight of the paper Cellulosic fibers, and more preferably, non-synthetic fibers, such as cellulosic fibers.

In particular, in a preferred embodiment, the fibers of the paper according to the invention are exclusively composed of micronized synthetic fibers and non-micronized synthetic fibers.

Treatments

By introducing polymeric binders such as polyvinyl alcohol (PVA) or styrene-acrylic copolymers that exhibit synergy with synthetic fibers and significantly improve not only folding resistance but also tear resistance, the cohesion of the paper according to the invention is enhanced . The polymeric binder can be added by impregnation, surface treatment or coating, and the polymeric binder is preferably at least partially introduced into the bulk.

The composition may in particular comprise aggregated anionic polymer dispersions. Preferably, the composition has, in particular, a dry weight of at least 3% of the aggregated anionic polymer dispersion. Such anionic polymer dispersion can improve the wet tensile strength, cohesion and folding resistance of the paper.

The latex used is, for example, a latex marketed by Dow Chemical under the reference 94755.04 or a latex as disclosed in international application WO 2008152299 or application WO 2014083527.

The formulation of the paper according to the invention may also comprise a first cationic coagulant of 1% to 5% dry weight, and optionally a cationic resin, polyacrylamides, polyethyleneimines, polyvinylamines and Their mixtures, preferably cationic resins, more preferably 0.1% to 0.5% dry weight of a second cationic coagulant, selected from polyamide-amine-epichlorohydrin resin.

In particular, other binders may be used, such as transparent or translucent elastomeric binders such as polyurethane and colloidal silicic acid, or acrylic polymers or styrene-acrylic copolymeric binders.

In order to enhance the strength of the paper, for example, floc (aggregates) of polyurethane with a high elongation at break of more than 600% are used in an amount of from 5% to 45% Can be incorporated into the paper by anionic dispersion at the dry weight.

Other constituents of paper

The paper according to the present invention can be applied to any of the additives used in the manufacture of conventional paper by the papermaking process, such as fillers, retention agents, fixing agents and / or wet strength agents, in particular epichlorohydrin resins And compounds.

The paper according to the invention may in particular comprise plastic, such as pore fillers, in particular polyvinyl chloride (PVC) particles, for example sold under the reference Lacovyl Pb 1302 by Kem One.

Manufacture of paper

The paper according to the present invention can be prepared by conventional techniques for the production of cellulose paper, except in the absence of cellulose fibers, steps specifically related to the presence of cellulose fibers. In particular, purification steps with high energy consumption can be usefully omitted.

The manufacturing method can be adapted to the presence of security elements such as watermarks or hidden lines.

Preferably, the paper may have a bulk of 2.5 cm ³ / g or less, preferably a bulk of 2 cm ³ / g or less, more preferably 1.5 cm ³ / g or less.

The paper may have a thickness of 100 mu m to 300 mu m, preferably 100 mu m to 150 mu m. It is measured according to the standard ISO 534 "paper and cardboard-determination of weight ".

Watermark

The paper according to the present invention may include a watermark. Such a watermark can be formed on a cylinder mold or a flat table.

The watermark may be, for example, bright and / or dark, in any known form, and may alternatively be multi-tone or multi-tone, for example as disclosed in patent EP 1 122 360, EP 2 350 384 and EP 2 550 395 It can have a multi-tone effect.

Silver line

The paper according to the invention may comprise a hidden line introduced into the bonded bulk in the wet stage or between two layers of the paper according to the invention. The hidden line can be at least partially introduced into the paper.

The paper may in particular comprise cellulose fiber ribbons as disclosed in application WO2008043965, in particular plastic ribbons or knitted ribbons as disclosed in application WO2006016088.

The hidden lines may be provided with metallization and / or holographic and / or interference effects and / or optical structures, especially lenses or mirrors.

Multilayer paper

The paper according to the invention can be single-layer or multi-layer.

In the case of a multi-layer structure, the layers may or may not have the same fiber composition. In particular, the paper may on the one hand comprise a layer of synthetic fibers according to the invention and on the other hand comprise a layer of cellulose fibers which, after being assembled in a wet stage on the layer according to the invention, have.

As a variant, the paper is used on the one hand, in particular on the basis of the transparency and quality of the formation of the sheet, in particular on paper, and the watermarks according to the invention which promote the rendering of the watermark, On the other hand, the fiber composition may comprise a layer of synthetic fibers according to the invention, which promotes mechanical strength properties and the layers are assembled in a wet process.

These layers may or may not be the same color.

Properties

The Bendtesn porosity of the paper can be from 0 mL / min to 10000 mL / min, preferably from 1 mL / min to 7000 mL / min. It is measured according to standard ISO 5636-3 "paper and paperboard: determination of air-permeability (average value); part 3: Bendtsen method ".

Preferably, the Schopper double fold resistance of the paper according to the present invention is greater than 5000, preferably greater than 20000, more preferably greater than 50,000. It is measured according to the standard ISO 5626 "paper; determination of folding resistance ".

Preferably, the tear resistance of the paper (measured in accordance with standard ISO 1974) is greater than 1000 mN, preferably greater than 2000 mN, more preferably greater than 3000 mN. It is measured according to the standard ISO 1974 "Measurement of paper-tear resistance, Elmendorf method".

The present invention makes it possible to produce high quality watermarks of satisfactory resolution, if necessary, while its mechanical properties, in particular folding resistance and tear resistance, can result in a higher synthetic paper than conventional paper.

The use of synthetic fibers that are less wettable and less sensitive to water than cellulose fibers can result in increased durability and, in particular, a substrate that is more resistant to attack by molds.

Security Elements and Security Documents

The paper according to the present invention preferably includes a watermark or a security element such as a hidden line introduced into the window (s), for example, as described above.

The invention also relates to a security document comprising a paper according to the invention.

In a preferred embodiment of the present invention, the secure document is a banknote. In addition, the security document may be a "prelam" insert for a smart card, in particular a check or restaurant voucher, an identification card, a visa, a passport, in particular an identity data page of the passport, a security sleeve, Other forms of payment, such as an "inlay", or a ticket for a driver's license, a lottery ticket, a travel ticket, a cultural or sporting event, a play card, or a recipient telegraph charge may be configured. The insert is preferably a layer that supports a wireless-frequency solid state communication device.

A secure document produced using paper according to the present invention and / or paper according to the present invention may have one or more additional security elements as defined below.

Among the additional security factors, some can be detected visually, day-to-day or in artificial light, without the use of special equipment. These security elements include, for example, colored fibers or strips. These security elements are named as the first level.

Other forms of additional security factors can only be detected using relatively simple facilities, such as a lamp that emits ultraviolet (UV) or infrared (IR) radiation. These security elements include, for example, fibers, strips or particles. These security elements may or may not be visible to the naked eye and are, for example, luminous when illuminated using a Wood's lamp that emits a wavelength of 365 nm. These security elements are named as the second level.

Other forms of additional security factors require more complex detection equipment for detection. These security elements may generate a particular signal, for example, when they are exposed, whether or not they are simultaneously to one or more external excitation sources. Automatic detection of the signal allows the authenticity of the document to be verified if applicable. These security elements may include tracers in the form of, for example, active materials, particles or fibers, which can generate a particular signal when these tracers are exposed to an optical, electrical, magnetic or electromagnetic excitation. These security elements are named as the third level.

 Additional security elements or elements may be present in the paper according to the present invention, or a security document according to the present invention may have first, second, or third level security characteristics.

When the formulation of the synthetic fiber composition comprises thermofusible thermoplastic materials, especially polyethylene fibers, additional security elements or elements can be secured to the document by simple heating, thus avoiding the use of hot-melt adhesives do.

Comparative tests

In order to demonstrate the useful properties of the paper according to the invention, the following various comparative experiments have been carried out.

- tear resistance measured in accordance with standard ISO 1974,

- fold resistance (or double fold, so-called "schopper fold") measured in accordance with standard ISO 5626,

- the weight measured in accordance with standard ISO 536,

- a thickness which is measured in accordance with standard ISO 534 and which achieves the same bulk (or volume) as the thickness divided by weight,

- The quality of the watermark visually assigned using scores from 1 (bad) to 6 (very good).

Raw substrates without any treatment as described above and surface treated substrates impregnated with a composition of polyvinyl alcohol or a composition of styrene-acrylic copolymer were tested.

The properties (example 1) of the substrate composed of the fiber composition consisting of the finely divided synthetic fibers and the non-micronized synthetic fibers having the circular cross-section are such that the fiber composition has a part of the non-micronized synthetic fibers having the circular cross- It was compared with those of the corresponding description of example 1 (example 2), except for the fact that it was replaced.

Example 1 Example 2 Micronized polyethylene fibers SWP E400 66% 66% Non-micronized fibers of circular cross-section polyamide 6.6 Rhodia 1.7 dtex semi-matt 4 mm 30% 10% Wramp W101 Polyamide / polyester Rectangular cross-section non-micronized fibers 20% Non-processed substrate weight g / m ² 88.2 85.5 Tear resistance mN 511 1518 Quality of watermark score 3.0 2.8 The surface treated substrate weight g / m ² 105.7 115.9 bulk cm ³ / g 1.40 1.37 Tear resistance mN 1884 2005 Folding resistance Folding times 8033 23787

The ratio is expressed in weight units

The results shown in Table 2 indicate that a mixture of non-micronized synthetic fibers of different cross-sections and different shape factors, with circular and rectangular cross-sections in this case, It reflects the fact that resistance can be increased. Satisfactory properties, especially good tear resistance, were obtained.

Example 3 Example 4 Micronized polyethylene fibers CFF 111-2 10% 10% Micronized polyethylene fibers SWP E400 76% 76% Non-micronized fibers of a circular cross-section of polyamide 6.6
Rhodia 1.7 dtex semi-matt 4 mm 10% Wramp W101 Rectangular cross-section polyamide / polyester fibers 10% Non-processed substrate weight g / m ² 88.2 86.4 Tear resistance mN 702 856 Quality of watermark score 6 4.5 The surface treated substrate weight g / m ² 92.8 96.6 bulk cm ³ / g 1.41 1.45 Tear resistance mN 1082 701 Folding resistance Double number 1387 254

The ratio is expressed in weight units

The properties of the substrate (example 3) composed of the finely divided synthetic fibers and the non-micronized synthetic fibers of the circular cross section are such that the non-micronized synthetic fibers of the circular cross section are completely replaced by the non-micronized synthetic fibers of the rectangular cross section Except that the fiber composition was compared to those of the corresponding description of example 3 (example 4).

The results shown in Table 3 indicate that the complete substitution of non-micronized synthetic fibers of the circular cross-section and non-micronized synthetic fibers of the rectangular cross-section can not significantly increase the tear resistance and folding resistance and degrades the quality of the watermark Reflect. As evidenced by a comparison of the examples, the non-micronized synthetic fibers with different shape factors, i.e. the combination of the fibers of the circular cross-section and the fibers of the rectangular cross-section in the examples considered, do not excessively reduce the quality of the watermark It is possible to increase the tearing resistance and the folding resistance.

Based on the intended application, it may be particularly important to obtain a denser, less porous substrate that allows for the quality of the watermark to be produced.

The properties of the substrate (example 5) composed of 76% of the finely divided synthetic fibers, the non-micronized synthetic fibers of the circular cross-section and the 10% of the non-micronized synthetic fibers of the rectangular cross-section were compared as follows:

- on the one hand, for those of the substrate composed of 56% dlm finely divided synthetic fibers, circular non-micronized synthetic fibers and 30% non-micronized synthetic fibers of a rectangular cross-section (example 6), and

On the other hand, for the example of the example 5 (example 7) of the mixture of 56% of the finely divided synthetic fibers and the mixture of the circularly-sectioned non-micronized synthetic fibers and the non-micronized synthetic fibers of the rectangular cross-section, .

The results shown in Table 4 reflect the fact that the fiber compositions of examples 6 and 7 can achieve very high levels of tear resistance and folding resistance after surface treatment. In addition, Wramp W101 fibers exhibit better tear resistance than Tejin TA 14N fibers, thus emphasizing the benefits of using multi-component basis fibers.

Example 5 Example 6 Example 7 Micronized polyethylene fibers SWP E400 76% 56% 56% Non-micronized fibers of a circular cross-section of polyamide 6.6
Rhodia 1.7 dtex semi-matt 4 mm 10% 10% 10% Wramp W101 Rectangular cross-section polyamide / polyester 10% 30% 15% Teijin TA 14N Rectangular cross-section of polyester fibers 15% Non-processed substrate weight g / m ² 89.6 92.2 86.5 Tear resistance mN 919 2932 1852 The surface treated substrate weight g / m ² 94.9 106.3 93.8 bulk cm ³ / g 1.35 1.44 1.45 Tear resistance mN 1042 3770 1791 Folding resistance Double number 1029 > 15000 > 17000

The ratio is expressed in weight units

The phrase "comprising" should be understood as a synonym for "including at least one" unless the context clearly indicates otherwise.

1 ... foundation fiber
2 ... first component
3 ... second component

Claims (28)

In paper,
Fibrillated synthetic fibers;
Nonfibrillated synthetic fibers having a cross-section with a first aspect modulus; And
The non-micronized synthetic fibers having a cross-section having a second type factor greater than the first type factor.
In claim 1,
Wherein the non-micronized synthetic fibers of the first aspect modulus have a shape factor of 1.3 or less, preferably 1.1.
In claim 1 or 2,
Wherein the non-micronized synthetic fibers of the second aspect modulus have a shape factor of 3 or less, preferably 5, more preferably 10.
The method according to any one of claims 1 to 3,
Wherein the non-micronized synthetic fibers of the first aspect modulus are fibers of circular cross-section.
The method according to any one of claims 1 to 4,
Wherein the undrawn synthetic fibers of the second type modulus are fibers of flat cross-section, preferably rectangular cross-section.
The method according to any one of claims 1 to 5,
Wherein the difference between the first shape factor and the second shape factor is 3 or greater, preferably 5, and preferably 10.
The method according to any one of claims 1 to 6,
The non-micronized synthetic fibers of the second aspect modulus are selected from the group consisting of those derived from the dissociation of multi-component basis fibers, preferably two-component fibers, more preferably two-component polyester / polyamide fibers in the pulp used in the manufacture of paper , Paper.
In claim 7,
Wherein the multi-component basis fibers are conjugated fibers, preferably polyester / polyamide fibers.
The method according to any one of claims 1 to 8,
Wherein the weight of the non-micronized synthetic fibers of the second type modulus is greater than that of the fibers of the first type modulus.
The method according to any one of claims 1 to 9,
≪ / RTI > further comprising a security element.
The method according to any one of claims 1 to 10,
A paper further comprising a watermark.
The method according to any one of claims 1 to 11,
Wherein the non-micronized synthetic fibers are selected from polyamide fibers, poly (ethylene terephthalate) fibers, polyvinyl alcohol fibers, fibers of ethylene vinyl alcohol copolymer and polyolefin fibers, preferably polyethylene fibers. .
The method according to any one of claims 1 to 12,
Characterized in that it comprises a dry weight of more than 5%, preferably a dry weight of more than 10%, more preferably more than 20% of dry weight of non-micronized synthetic fibers, relative to the total weight of the paper,
In particular, the amount of non-micronized synthetic fibers of the second type modulus having a form factor of at least 3 is at least 10% dry weight based on the total weight of the paper.
The method according to any one of claims 1 to 13,
Wherein the micronized synthetic fibers are micronized polyethylene fibers.
The method according to any one of claims 1 to 13,
Wherein the non-micronized synthetic fibers have a number-average length of from 0.5 mm to 8 mm, preferably from 2 mm to 8 mm, more preferably from 4 mm to 6.5 mm.
The method according to any one of claims 1 to 15,
A dry weight of less than 95% dry weight, preferably less than 90% dry weight, more preferably less than 80% dry weight of finely divided synthetic fibers, relative to the total weight of the paper.
The method according to any one of claims 1 to 16,
In particular, it includes a surface treatment agent impregnated with a surface treatment agent,
The surface treatment agent preferably comprises or consists of polyvinyl alcohol.
The method according to any one of claims 1 to 17,
In particular, the paper comprises agglomerated latex.
The method according to any one of claims 1 to 18,
A paper, in particular a cohesive latex, with a dry weight of at least 3%, based on the total weight of the paper.
The method according to any one of claims 1 to 19,
Non-synthetic fibers such as cellulose fibers having a dry weight of less than 5%, preferably less than 2% of dry weight, relative to the total weight of the paper, and more preferably no non-synthetic fibers such as cellulose fibers, Paper.
The method according to any one of claims 1 to 20,
Wherein the fibers of the paper are exclusively composed of micronized synthetic fibers and non-micronized synthetic fibers.
The method according to any one of claims 1 to 21,
A bulk of less than 2.5 cm < ³ > / g, more preferably less than 2 cm < ³ > / g.
The method according to any one of claims 1 to 22,
Of 70g / m ² to 150g / m ^2, and preferably, 90g / m ² to including a weight of 110g / m ^2, paper.
The method according to any one of claims 1 to 23,
Having a Schopper double fold resistance of at least 5,000, preferably at least 10,000, more preferably at least 25,000.
The method according to any one of claims 1 to 24,
Having a tear resistance measured according to standard ISO 1974 of more than 1000 mN, preferably more than 2000 mN, more preferably more than 3000 mN.
26. The method according to any one of claims 1 to 25,
In particular, a hidden line at least partially introduced into the paper.
A security document comprising a paper according to any one of claims 1 to 26.
In claim 27,
Such as banknotes, checks, restaurant vouchers, identification cards, visas, passports, security labels, security sleeves, passports or cards that can be pulled off thermally, in particular smart card inserts, or license plates, lotteries, travel tickets, Or a security document that constitutes an identity document that includes a sports event ticket, a height card, or a card worth collecting.

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