Title of Invention	A FLAT SECURITY ELEMENT FOR A SECURITY PAPER, A SECURITY PAPER AND METHOD OF PRODUCTION THEREOF
Abstract	The invention relates to a planar security element for a security paper valtrable dacumcnt or the like, comprising a substrate (20) with two opposite main surfaces. The aim of the invention is to improve the embedding of the security element (12) into a security paper or a va;lualble elements . For this purpose. at least main surface of the substrate (30) is pcovided with a spatially structured coating, e.g. a fiber coaling (22). (57) Zusammeniussing: DieEifindung flachiges Sichertreselement flirein Sichertreselement . Wermdokument order der-gleichert miteinem Stbstral (20) mit zurd XXX Hanpfilachen. Erfindungsgenvifi ist zur Verbesserung der Enbeterng des Sichertreselement (12) in cin. cin Sichertreselement order ein Wendokument zumindest ripe Hamplflache ripe Hamplache des Substrsts(20)mit

Title of Invention

A FLAT SECURITY ELEMENT FOR A SECURITY PAPER, A SECURITY PAPER AND METHOD OF PRODUCTION THEREOF

Abstract

The invention relates to a planar security element for a security paper valtrable dacumcnt or the like, comprising a substrate (20) with two opposite main surfaces. The aim of the invention is to improve the embedding of the security element (12) into a security paper or a va;lualble elements . For this purpose. at least main surface of the substrate (30) is pcovided with a spatially structured coating, e.g. a fiber coaling (22). (57) Zusammeniussing: DieEifindung flachiges Sichertreselement flirein Sichertreselement . Wermdokument order der-gleichert miteinem Stbstral (20) mit zurd XXX Hanpfilachen. Erfindungsgenvifi ist zur Verbesserung der Enbeterng des Sichertreselement (12) in cin. cin Sichertreselement order ein Wendokument zumindest ripe Hamplflache ripe Hamplache des Substrsts(20)mit

Full Text	Flat security element [0001] This invention relates to a flat security element for a security paper, value document or the like having a substrate with two opposite main faces, The invention relates further to a security paper and a value document having such a security element and to a method for producing a security paper having such a security element. [0002] It is known to embed, security elements in the form of threads or bands in se- curity papers cr value documents, such as back notes, papers of value, identity cards or other papers at risk of forgery. "Security paper" will hereinafter be understood to mean paper that is already equipped with security elements such as a watermark, security thread, hologram patch, etc., but not yet printed, "Value document" will be understood to mean the printed security paper, e.g. the printed bank note. [0003] The security threads or bands are as a rule incorporated into the paper during papermaking. For example, the security thread is introduced into the paper stock upon use of a cylinder paper machine and fed to the cylinder in such a way teat the thread is embedded in the fiber structure of the paper during sheet formation. [0004] Methods are also knovm for embedding a security thread in the paper in the form of a so-called windowed security thread, which is visible in certain areas on the surface of the paper of value. For example, EP-A 0 059 056 describes a method by which the security thread is fed to the papermaking screen outside the paper stock in such, a way that it comes to lie on raised places provided thereon. At the places where the security thread rests on the raised places no paper can form on the side facing the screen, so that the security thread is visible in the finished paper at these places. [0005] In practice it has turned out in the embedding of security threads with differ- ent widths that sheet formation is impaired above and below the thread by the drain- age-inhibiting effect of the thread. This effect increases with the thread width and of- ten leads to defects, such as holes, in the paper in the case of wide threads. To obtain sufficient sheet quality, the method known from EP-A-0 059 056 is therefore limited to the embedding of threads with a width up to about 1 mm to 1.5 mm, -2- [0006] To permit embedding of security bands with a width up to about 4 mm, it is therefore proposed in the print EP-A-0 625 431 to deliberately accept the defects ap- pearing only on the back of the later security paper when using bands that are not too wide, and to cover them with one or two fault-free paper layers in a subsequent method step. This always ensures a minimum paper thickness even in the area of the defects, which conveys to the viewer a homogeneous impression of the paper surface. [0007] In almost all security and bank-note papers, a thread coated with heat seal lacquer is incorporated into the paper on the paper machine as the security thread, to- day. The heat peal lacquer serves to improve the anchorage of the thread in the paper. The width of these threads typically made of PET film is up to 3 mm, in rare cases also between 3 mm and 4 mm. [0008] Fault-free sheet formation is increasingly impeded primarily with threads having a width of 3.5 mm or more. As a result so-callud thread streaks appear, where the paper ply no longer forms a completely closed fiber structure in the area of the thread. The choice of thread and the thread design are therefore limited in practice to widths up to about 4,0 mm. [0009] On these premises, die present invention is based on the problem of specify- ing a security element that avoids the disadvantages of the prior art. In particular, it should be possible to incorporate the security element into security papers or value documents reliably and with little effort, even if it has a large width, or large surface area, in such a way as to yield a uniform and unimpaired appearance without defects. [0010] This problem is solved by the security element having the features of the main, claim. A security paper, a value document as well as a method for producing a security paper are the subject matter of the coordinated claims. Developments of the invention are the subject matter of the subclaims. [0011] According to the invention, at least one main face of the substrate is pro- vided with a three-dimensionally structured coating in the security element of the type stated at the outset. - 3 - [0012] According to the invention, the three-dimensionally structured coating may be a fiber coating, a foamed, embossed and/or filled coating. [0013] In an advantageous, embodiment at least one main, surface is provided with a fiber coating. Said fiber coating is integrated into the fibrous mesh of the paper during papermaking so as to prevent the paper ply from thinning in the area of the security element as known from the prior art. [0014] The fiber coaling is preferably formed by a textile fabric, in particular a woven, a knit, a felt, a nonwoven, or a flocking with or coating of single fibers. It is also possible to use a closed fiber material, such as paper, in particular cotton paper. The fabrics can be formed directly from the fibers, as in the case of felts or nonwov- ens, or from yarns, as in the case of wovens, knits or braids. A woven designates here a fabric produced by the interlacing of at least two different thread systems (warp and weft), while in knits the thread or threads are entwined in meshed loops. Felts are me- chanically consolidated, woven, sheets or fibrous webs. Nonwovens refer to nonwoven fabrics with usually randomly oriented fibers whose cohesion can already be given by the fibersT own. adhesion. Furthermore, the nonwovens can also be mechanically or chemically consolidated. [0015] According to a preferred embodiment of the invention, the fiber coating comprises synthetic fiber raw materials, in particular selected from the group of vis- cose, aramid, PVAL (polyvinyl alcohols), PET (polyethylene terephthalates), PA (polyamides) and polyolefins, preferably PP (polypropylenes). [0016] According to a Likewise preferred embodiment of the invention, the fiber coating comprises natural fibers, in particular selected from, the group of wool, silk, cotton, plant fibers, paper fibers and cellulose. [0017] The fiber coating can also comprise bicomponent fibers or multicomponent fibers, in particular made of the stated synthetic fiber raw materials or natural fibers. [0018] Obviously, the stated fibers can also appear in the fiber coating in combina- tion. For example, a partial area of the substrate of the security element can be coated -4- with synthetic fibers, another partial area with natural fibers. In particular, the two main faces of the substrate can be provided with different fiber coatings. [0019] According to an expedient embodiment of the invention, the fiber coating comprises a fibrous mat with a low weight per unit area, in particular with a weight per unit area of 8 to 30 g/m2 or less, preferably of l5 g/m2 or less. [00201 According to another advantageous embodiment, the fiber coating comprises a woven with weft and warp threads made of different material. Expediently, one of the material threads is water-soluble. A fibrous mat or a fiber knit made of fibers with different diameter and/or different titer can also be advantageously used. [0021] Expediently, the fiber coating is connected to the substrate via an adhesive layer. The adhesives used may be for example solvent-based adhesives, dispersions, hot-melts, heat seal lacquers, synthetic 1C and 2C adhesives, ionomers, styrene acry- lates and mixtures thereof, [0022] According to an advantageous development of the invention, the fiber coat- ing is provided with an adhesive coating, in particular a heat-activable adhesive or a hot-melt adhesive, for embedding the security element in a security paper, value document or the like. The fiber coating can also bave a hydrophtlic coating as an addi- tional coating. It may likewise be expedient to increase the polarity of the fibers by a corona or plasma pretreatmeat before embedding in the security paper or value docu- ment to obtain an improved bond with the stock, fibers. [0023] In a further advantageous embodiment, the three-dimensionally structured coating is an embossed coating. The embossed coating may be a heat-activable adhe- sive or a non-heat-activable adhesive, such as PUR, or non-heat-activable films, such as PA, PET, PP The coating preferably comprises a heat-activable hot-melt adhesive. The embossing is produced e.g. by means of a structured embossing roll. The depti of the embossing is between about 1 to 10 m, preferably about 3 to 6 m. The emboss- ing supports the depositing of fibers from the paper stock on the security element. The embossing is preferably equatized again in the press or dryer section or the smoothing -5- machine, that is, after the actual sheet formation. The adhesives to be used are the above-mentioned adhesives. [0024] In a further advantageous embodiment, the three-dimensionally structured coating is a foamed coating. The coating is in particular a heat-activable hot-melt ad- hesive or a film, such as HDPE, PP, OPP, PET, PA, which has been foamed e.g. by carbonates, hydrogenearbonates or other foarning agents. The pore structure present in the coating permits the depositing and penetration of fibers from the paper stock on the security element. Upon use of an adhesive, the pore sizes preferably range from about 1 to 200 m, especially preferably from 40 to 50 m. Upon use of foamed films, the pore sizes preferably range from about 50 to 500 m, especially preferably from about 30 to 100 m, The pore structure is preferably equalized again, in the press or dryer section or the smoothing machine upon use of meheat-activable hot-melt adhesive, while the foaming is preferably retained upon use of a film. [0025] In a further advantageous embodiment of the invention, the three- dimensionally structured coating is a filled coating. The coating is preferably a film, e.g. HDPE, PP, OPP, PET, PA, which has fillers. The fillers used are advantageously chalk, SiO2, A12O3, TiO2, ZrO2, talc, Acrosil, MgO or BaSO4, The particle size pref- erably ranges up to about 40 m in diameter. The filler content based on the film pref- erably ranges from about 5 to 20 wt%, The fillers preferably lead to a roughening of the film, which mates it more difficult for the fibers from the paper stock to run off the security element. [0026] The inventive three-dimensionally structared coating can advantageously be additionally equipped with water-soluble properties. For example, a surface-structured PYA coating can be present in the security element. In the wet section of the paper machine the PVA coating is partially dissolved and prevents the pulp from washing away by integrating fibers from the paper stock. Sheet formation in the film area is thus facilitated [0027] It is of course also possible to combine the individual above-described in- ventive embodiments. -6- [0028] In an advantageous "variant of the invention, only one main face of the sub- strate is prorvided with a three-damensionally structured coating. This variant is used in particular when the seciarity element is embedded in a security paper or value docu- ment in the manner of a. windowed security thread. [0029] If the security element is embedded in the paper all over, it has proved espe- cially expedient if both, main faces of Sue substrate are provided with a three- tlimensionally structured coating. The main faces can be provided either with similar coatings or with different coatings. [0030] The main face(s) of the substrate are expediently provided with, the three- dimensionally structured coating all over for optimal embedding. Depending on the size of the security element, however, it may also suffice to provide the coating on only a partial area of the substrate thereof, for example an edge area. [0031] It is also possible to apply a coating in sections on one side or a coating al- ternating on the two main faces. For further support of the anchorage of the security element in the paper, the security element can additionally be designed with perfora- tions, preferably in the edge area of the element. [0032] In a preferred embodiment, the security element is designed in the form of a security band which is intended for complete or partial embedding in a security paper or value document.. The security band is designed in particular in the form of a rectan- gular band with length L and width B, the tength L as a role corresponding to a typical dimension of the security paper in which the security element is embedded. The inven- tive solution shews special advantages if the security band is formed with a width, of about 4 mm to about 20 mm, [0033] In other, likewise advantageous embodiments, the security element is de- signed in the form of a security stripe, a patch or another flat element. During produc- tion of a security paper the flat element is preferably applied to the still moist paper web, so that the fibers of the paper web can mesh with the fibers of the coating. -7- [0034] To further increase the falsification security, the security element can be equipped with an optically variable effect, in particular a diffraction, pattern, a. holo- gram, a color shift effect or other interference effects, [0035] According to another preferred embodiment the security element is pro- vided with a printed image or with positive or negative gaps in an opaque layer, e.g. a metal layer, in the form of patterns or characters. The security element can also contain fluorescent substances, phosphorescent substances or magnetic, substances as a farther security feature. In all these embodiments, additional design options result compared to conventional security threads due to the greater possible width of the security ele- ment. For example, large-area print designs, such as flags, architectural motifs or por- traits, can be used on a security band for the first time. [0036] The invention also comprises a security paper for producing security or value documents, such as bank notes, identity cards or the like, which is equipped with an above-described security element, as well as a value document having such a secu- rity element. The security element can be completely embedded in the security paper or value document. Alternatively, the security element is embedded in the security pa- per or value document in the manner of a windowed security thread and is visible in window areas of the security paper or value document on the surface thereof. These- curity clement can also form a pendulating security thread, which appears alternatingly on opposite surfaces of the security paper or value document. [0037] To make the security element inside the security paper or value document as unobtrusive as possible in reflected light, the three-dimensional structuring of the secu- rity element surface can be selected so that it bas substantially the same optical ap- pearance as the paper substrate in which the security element is embedded, In particu- lar, the fiber costing can have the same color as the paper substrate. If a fiber coating with an optically divergent appearance is alternatively selected, the contrast between security element and paper substrate can also be used deliberately as a design element. [0038] In a method for producing a security paper of the described type, a paper web is formed in a first method step, a security band with a substrate with, two oppo- site main faces being embedded completely or partly in the paper during sheet forma- -8- tion. According to the invention, at least one surface of a main face of the substrate is provided with a three-dimensional structure, in. particular a fiber coating, before em- bedding, [0039] According to preferred embodiments, the substrate of the security band is flocked or coated with single fibers or laminated with a fiber coating in the form of a textile fabric, in particular a woven, a knit, a felt or a noawoven. It is advantageous to use here the synthetic fiber raw materials or natural fibers that are mentioned above, [0040] For improved embedding of the security band in the security paper, the fiber coating is preferably provided with an adhesive coating. The fiber coating can also be provided with a hydrophilic coating, or the polarity of the fibers can be increased by a corona or plasma pretreatment to improve the embedding. [0041] Further embodiments as well as advantages of die invention will be ex- plained hereinafter with reference to the figures. For more clarity, the figures do with- out a representation that is true to scale and to proportion. Fig, 1 shows a schematic representation of a bank note with a wide windowed se- curity band according to one embodiment of the invention, Fig. 2 shows the windowed security band of Fig. 1 in cross section along the line II-II, and Fig. 3 shows a security band according to another embodiment of the invention in cross section. [0042] The invention will be explained hereafter by the example of a bank note Fig. 1 shows a schematic representation of a bank note 10 with an embedded wide windowed security band 12 in a front view. The windowed security band 12 appears on the surface of the bank note 10 at window areas 14, while it is embedded inside the bank note 10 in the areas 16 there between. [0043] The windowed security band 12 has a width of about 15 mm in this em- bodiment. To permit such a wide security band to be embedded in the bank note 10 -9- without thread streaks, the windowed security band 12 is provided with a fiber coating on its underside. Fig. 2 shows schematically the structure of the windowed security band 12, A fibrous mat 22, in the embodiment a cotton mat, with a weight per unit area of about 15 g/m2 is applied to a PET substrate film 20. The fibrous mat 22 is firmly connected to the substrate 20 via an adhesive layer of heat seal lacquer. [0044] The windowed security band 12 is embedded, in the paper web in the way known in the art during production of the security paper for the bank note 10. The fi- brous mat 22 bereases the adhesion of the cellulose fibers to the surface of. the secu- rity band. 12 and leads to closed sheet formation, despite the large width of the band, via the considerably improved embedding of the security band 12 in the fiber bond of the security paper. The security band 12 can be equipped with further security features not shown in the figure, for example a hologram element or a print design. [0045] Fig. 3 shows a security band 30 for complete embedding in a security paper according to another embodiment of the invention. The security band 30 contains a PET or OPP substrate film 32 which is provided with a fiber coating 34, 36 on each side. In this embodiment the fiber coating is formed by a laminated knit of aramid fi- bers on each side. Further adhesive layers 38 and 40 on the fiber coatings 34 and 36 serve to strengthen the anchorage of the wide security band 30 in a security paper. [0046] The described security hand can be incorporated into a paper web not only with a cylinder paper machine. With a fourdrinier paper machine the security band can be supplied accordingly shortly before or shortly after the paper fiber layer leaves the screen in the same way as with a cylinder paper machine. -10- Claims 1. A flat security element for a security paper, value document or the like having a substrate (20; 32) with two opposite main faces, characterized in that at least one main face of the substrate (20; 32) is provided with a three-djmensionally struc- tured costing (22; 34,36). 2. The security element according to claim 1, characterized in that the three- dimensionally structured coaling is a fiber coating, a foamed, embossed and/or filled coating,. 3. The security element according to claim 1 or 2, characterized in that the fiber coating is formed hy a textile fabric (22; 34,36), in particular a woven, a. knit, a. felt, a nonwoven or a flocking with or a costing of single fibers. 4. The security element according to claim 2 or 3, characterized in that the fiber coating (34, 36) comprises synthetic fiber raw materials which are in particular selected from the group of viscose, aramid, PVAL, PET, PA and PP. 5. The security element according to at least one of claims 2 to 4, characterized in. that the fiber coating (22) comprises natural fibers which are in particular se- lected from the group of wool, silk, cotton, plant fibers, paper fibers and cellu- lose. 6. The security element according ro at least one of claims 2 to 5, characterized in. that the fiber coating comprises bicomponent fibers or multicomponent fibers, in particular made of the fiber raw materials stated in claim 4 or 5. 7. The security element according to any of claims 2 to 6, charscterized in that the fiber coating (22; 34, 36) comprises a fibrous mat with a weight per unit area of 8 to 30 g/m2 or less, preferably of .15 g/m2 or less. 8. The security element according to at least one of claims 2 to 7, characterized in that the fiber coating comprises a woven with weft and warp threads made of dif- ferent material. -11- 9. The security element according to claim 8, characterized in that one of the mate- rial threads is water-soluble. 10. The security element according to at least one of claims 2 to 9, characterized in that the fiber coating comprises a fibrous mat or a fiber kail made of fibers with different diameter and/or different titer. 11. The security element according to at least one of claims 2 to 10, characterized in that the fiber coating (22; 34,36) is connected to the substrate via an adhesive layer. 12. The security element according to at least one of claims 2 to 11, characterized in that the fiber coating (34, 36) is provided with an adhesive coating (38, 40), in particular a heat-activable adhesive or a hot-melt adhesive, for cmbedding or ap- plying the security element in or to a security paper, value document or the like. 13. The security element according to at least one of claims 2 to 12, characterized in that the fiber coaling (22- 34,36) is provided with, a hydrophilic coating. 14. The security element according to at least one of claims 2 to 13, characterized in that the polarity of the fibers of the fiber coating (22; 34, 36) is increased by a co- rona or plasma pretreatment. 15. The security element according to at least one of claims 1 to 14, characterized in lhat only one main face of the substrate (20) is provided with a three- dimensionally structured coating (22). 16. The security element according to at least one of claims 1 to 15, characterized in that both main faces of the substrate (32) are provided with a three-dimensionally structured coating (34, 36), 17. The security element according to at least one of claims 1 to 16, characterized in that die main face or faces of the substrate (20; 32) are provided with the three- dimensionally structured coaling (22; 34,36) all over. -12- 18. The security element according to at least one of claims 1 to 17, characterized in that the security element is designed in the form of a security baud (12; 30). 19. The security element seconding to claim 18, characterized in that the security band (12; 30) has a width of about 4 mm to about 20 m 20. The security element according to at least one of claims 1 to 19, characterized in that the security element is designed in the form of a security stripe, a patch or another flat element. 21. The security element according to at least one of claims 1 to 20, characterized in that the security element (12; 30) is equipped with an optically variable effect, in particular a diffraction pattern, a hologram, a color shift effect or other interfer- ence effects. 22. The security element according to at least one of claims 1 to 21 , characterized in that the security element (12; 30) is provided with a printed image or with posi- tive or negative gaps in an opaque layer in the form of characters or patterns. 23. The secvirity element according to at least one of claims 1 to 22, characterized in that the security element (12; 30) contains fluorescent substances, phosphores- cent substances or magnetic substances. 24. A security paper for producing security or value documents, such as bank notes, identity cards or the like, having a security element (12; 30) according to at least one of claims 1 to 23. 25. A value document; such as bank note, identity card or the like, having a security element (12; 30) according to at least one of claims 1 to 23. 26. The security paper or value document according to claim 24 or 25, characterized in that the security elament (30) is completely embedded in or applied to the se- curity paper or value document. 27. The security paper or value document according to claim 24 or 25, characterized in that the security element (12) is embedded in the security paper or value -13- document (10) and is visible in window areas (14) of the security paper or value document (10) on the surface thereof. 28. The security paper or value document according to claim 26 or 27, characterized in that the three-dimensionalty structured coating (22; 34, 36) of the security element (12; 30) has substantially the same optical appearance as the paper sub- strate in which the security element (12; 30) is embedded, 29. A method for producing a security paper according to at least one of claims 23 to 27 by which a paper web is formed in a first method step, a security element hav- ing a substrate with two opposite main faces being embedded completely or partly in the paper during sheet formation or applied to the paper after sheet for- mation, characterized in that at least one main face of the substrate is provided with a these-dimensionally structured coating before embedding or application, 30. The method according to claim 29, characterized in that the main face is pro- vided with a fiber coating. 31. The method according to claim 30, characterized in that the substrate of the secu- rity element is flocked of coated with single fibers. 32. The method according to claim 30 or 31, characterized in that the substrate of the security element is laminated with a fiber coating in. the form of a textile fabric, in particular a woven, a knit, a felt or a nonwoven. 33. The method according to at least one of claims 30 to 32, characterized in that the fiber raw materials of the fiber coating comprise synthetic fibers, in particular se- lected from the group of viscose, aramid, FVAL, PET, PA or PP, or comprise natural fibers, in particular selected from the group of wool, silk, cotton, plant fi- bers, paper fibers or cellulose, 34. The method according to at least one of claims 30 to 33, characterised in that the fiber coating is provided with an adhesive coating for improved embedding of the security element in the security paper or application to the security paper. -14- 35. The method according to at least one of claims 30 to 34, characterized in that the fiber coating is provided with a- hydrophilic coating. 36. The method according to at least one of claims 30 to 35, characterized in that the polarity of the fibers of the fiber coating is increased by a corona or plasma pre- treatment to improve the embedding. The invention relates to a planar security element for a security paper valtrable dacumcnt or the like, comprising a substrate (20) with two opposite main surfaces. The aim of the invention is to improve the embedding of the security element (12) into a security paper or a va;lualble elements . For this purpose. at least main surface of the substrate (30) is pcovided with a spatially structured coating, e.g. a fiber coaling (22). (57) Zusammeniussing: DieEifindung flachiges Sichertreselement flirein Sichertreselement . Wermdokument order der-gleichert miteinem Stbstral (20) mit zurd XXX Hanpfilachen. Erfindungsgenvifi ist zur Verbesserung der Enbeterng des Sichertreselement (12) in cin. cin Sichertreselement order ein Wendokument zumindest ripe Hamplflache ripe Hamplache des Substrsts(20)mit

Full Text

Flat security element
[0001] This invention relates to a flat security element for a security paper, value
document or the like having a substrate with two opposite main faces, The invention
relates further to a security paper and a value document having such a security element
and to a method for producing a security paper having such a security element.
[0002] It is known to embed, security elements in the form of threads or bands in se-
curity papers cr value documents, such as back notes, papers of value, identity cards or
other papers at risk of forgery. "Security paper" will hereinafter be understood to mean
paper that is already equipped with security elements such as a watermark, security
thread, hologram patch, etc., but not yet printed, "Value document" will be understood
to mean the printed security paper, e.g. the printed bank note.
[0003] The security threads or bands are as a rule incorporated into the paper during
papermaking. For example, the security thread is introduced into the paper stock upon
use of a cylinder paper machine and fed to the cylinder in such a way teat the thread is
embedded in the fiber structure of the paper during sheet formation.
[0004] Methods are also knovm for embedding a security thread in the paper in the
form of a so-called windowed security thread, which is visible in certain areas on the
surface of the paper of value. For example, EP-A 0 059 056 describes a method by
which the security thread is fed to the papermaking screen outside the paper stock in
such, a way that it comes to lie on raised places provided thereon. At the places where
the security thread rests on the raised places no paper can form on the side facing the
screen, so that the security thread is visible in the finished paper at these places.
[0005] In practice it has turned out in the embedding of security threads with differ-
ent widths that sheet formation is impaired above and below the thread by the drain-
age-inhibiting effect of the thread. This effect increases with the thread width and of-
ten leads to defects, such as holes, in the paper in the case of wide threads. To obtain
sufficient sheet quality, the method known from EP-A-0 059 056 is therefore limited
to the embedding of threads with a width up to about 1 mm to 1.5 mm,

-2-
[0006] To permit embedding of security bands with a width up to about 4 mm, it is
therefore proposed in the print EP-A-0 625 431 to deliberately accept the defects ap-
pearing only on the back of the later security paper when using bands that are not too
wide, and to cover them with one or two fault-free paper layers in a subsequent
method step. This always ensures a minimum paper thickness even in the area of the
defects, which conveys to the viewer a homogeneous impression of the paper surface.
[0007] In almost all security and bank-note papers, a thread coated with heat seal
lacquer is incorporated into the paper on the paper machine as the security thread, to-
day. The heat peal lacquer serves to improve the anchorage of the thread in the paper.
The width of these threads typically made of PET film is up to 3 mm, in rare cases also
between 3 mm and 4 mm.
[0008] Fault-free sheet formation is increasingly impeded primarily with threads
having a width of 3.5 mm or more. As a result so-callud thread streaks appear, where
the paper ply no longer forms a completely closed fiber structure in the area of the
thread. The choice of thread and the thread design are therefore limited in practice to
widths up to about 4,0 mm.
[0009] On these premises, die present invention is based on the problem of specify-
ing a security element that avoids the disadvantages of the prior art. In particular, it
should be possible to incorporate the security element into security papers or value
documents reliably and with little effort, even if it has a large width, or large surface
area, in such a way as to yield a uniform and unimpaired appearance without defects.
[0010] This problem is solved by the security element having the features of the
main, claim. A security paper, a value document as well as a method for producing a
security paper are the subject matter of the coordinated claims. Developments of the
invention are the subject matter of the subclaims.
[0011] According to the invention, at least one main face of the substrate is pro-
vided with a three-dimensionally structured coating in the security element of the type
stated at the outset.

- 3 -
[0012] According to the invention, the three-dimensionally structured coating may
be a fiber coating, a foamed, embossed and/or filled coating.
[0013] In an advantageous, embodiment at least one main, surface is provided with a
fiber coating. Said fiber coating is integrated into the fibrous mesh of the paper during
papermaking so as to prevent the paper ply from thinning in the area of the security
element as known from the prior art.
[0014] The fiber coaling is preferably formed by a textile fabric, in particular a
woven, a knit, a felt, a nonwoven, or a flocking with or coating of single fibers. It is
also possible to use a closed fiber material, such as paper, in particular cotton paper.
The fabrics can be formed directly from the fibers, as in the case of felts or nonwov-
ens, or from yarns, as in the case of wovens, knits or braids. A woven designates here
a fabric produced by the interlacing of at least two different thread systems (warp and
weft), while in knits the thread or threads are entwined in meshed loops. Felts are me-
chanically consolidated, woven, sheets or fibrous webs. Nonwovens refer to nonwoven
fabrics with usually randomly oriented fibers whose cohesion can already be given by
the fibersT own. adhesion. Furthermore, the nonwovens can also be mechanically or
chemically consolidated.
[0015] According to a preferred embodiment of the invention, the fiber coating
comprises synthetic fiber raw materials, in particular selected from the group of vis-
cose, aramid, PVAL (polyvinyl alcohols), PET (polyethylene terephthalates), PA
(polyamides) and polyolefins, preferably PP (polypropylenes).
[0016] According to a Likewise preferred embodiment of the invention, the fiber
coating comprises natural fibers, in particular selected from, the group of wool, silk,
cotton, plant fibers, paper fibers and cellulose.
[0017] The fiber coating can also comprise bicomponent fibers or multicomponent
fibers, in particular made of the stated synthetic fiber raw materials or natural fibers.
[0018] Obviously, the stated fibers can also appear in the fiber coating in combina-
tion. For example, a partial area of the substrate of the security element can be coated

-4-
with synthetic fibers, another partial area with natural fibers. In particular, the two
main faces of the substrate can be provided with different fiber coatings.
[0019] According to an expedient embodiment of the invention, the fiber coating
comprises a fibrous mat with a low weight per unit area, in particular with a weight per
unit area of 8 to 30 g/m2 or less, preferably of l5 g/m2 or less.
[00201 According to another advantageous embodiment, the fiber coating comprises
a woven with weft and warp threads made of different material. Expediently, one of
the material threads is water-soluble. A fibrous mat or a fiber knit made of fibers with
different diameter and/or different titer can also be advantageously used.
[0021] Expediently, the fiber coating is connected to the substrate via an adhesive
layer. The adhesives used may be for example solvent-based adhesives, dispersions,
hot-melts, heat seal lacquers, synthetic 1C and 2C adhesives, ionomers, styrene acry-
lates and mixtures thereof,
[0022] According to an advantageous development of the invention, the fiber coat-
ing is provided with an adhesive coating, in particular a heat-activable adhesive or a
hot-melt adhesive, for embedding the security element in a security paper, value
document or the like. The fiber coating can also bave a hydrophtlic coating as an addi-
tional coating. It may likewise be expedient to increase the polarity of the fibers by a
corona or plasma pretreatmeat before embedding in the security paper or value docu-
ment to obtain an improved bond with the stock, fibers.
[0023] In a further advantageous embodiment, the three-dimensionally structured
coating is an embossed coating. The embossed coating may be a heat-activable adhe-
sive or a non-heat-activable adhesive, such as PUR, or non-heat-activable films, such
as PA, PET, PP The coating preferably comprises a heat-activable hot-melt adhesive.
The embossing is produced e.g. by means of a structured embossing roll. The depti of
the embossing is between about 1 to 10 m, preferably about 3 to 6 m. The emboss-
ing supports the depositing of fibers from the paper stock on the security element. The
embossing is preferably equatized again in the press or dryer section or the smoothing

-5-
machine, that is, after the actual sheet formation. The adhesives to be used are the
above-mentioned adhesives.
[0024] In a further advantageous embodiment, the three-dimensionally structured
coating is a foamed coating. The coating is in particular a heat-activable hot-melt ad-
hesive or a film, such as HDPE, PP, OPP, PET, PA, which has been foamed e.g. by
carbonates, hydrogenearbonates or other foarning agents. The pore structure present in
the coating permits the depositing and penetration of fibers from the paper stock on the
security element. Upon use of an adhesive, the pore sizes preferably range from about
1 to 200 m, especially preferably from 40 to 50 m. Upon use of foamed films, the
pore sizes preferably range from about 50 to 500 m, especially preferably from about
30 to 100 m, The pore structure is preferably equalized again, in the press or dryer
section or the smoothing machine upon use of meheat-activable hot-melt adhesive,
while the foaming is preferably retained upon use of a film.
[0025] In a further advantageous embodiment of the invention, the three-
dimensionally structured coating is a filled coating. The coating is preferably a film,
e.g. HDPE, PP, OPP, PET, PA, which has fillers. The fillers used are advantageously
chalk, SiO2, A12O3, TiO2, ZrO2, talc, Acrosil, MgO or BaSO4, The particle size pref-
erably ranges up to about 40 m in diameter. The filler content based on the film pref-
erably ranges from about 5 to 20 wt%, The fillers preferably lead to a roughening of
the film, which mates it more difficult for the fibers from the paper stock to run off the
security element.
[0026] The inventive three-dimensionally structared coating can advantageously be
additionally equipped with water-soluble properties. For example, a surface-structured
PYA coating can be present in the security element. In the wet section of the paper
machine the PVA coating is partially dissolved and prevents the pulp from washing
away by integrating fibers from the paper stock. Sheet formation in the film area is
thus facilitated
[0027] It is of course also possible to combine the individual above-described in-
ventive embodiments.

-6-
[0028] In an advantageous "variant of the invention, only one main face of the sub-
strate is prorvided with a three-damensionally structured coating. This variant is used in
particular when the seciarity element is embedded in a security paper or value docu-
ment in the manner of a. windowed security thread.
[0029] If the security element is embedded in the paper all over, it has proved espe-
cially expedient if both, main faces of Sue substrate are provided with a three-
tlimensionally structured coating. The main faces can be provided either with similar
coatings or with different coatings.
[0030] The main face(s) of the substrate are expediently provided with, the three-
dimensionally structured coating all over for optimal embedding. Depending on the
size of the security element, however, it may also suffice to provide the coating on
only a partial area of the substrate thereof, for example an edge area.
[0031] It is also possible to apply a coating in sections on one side or a coating al-
ternating on the two main faces. For further support of the anchorage of the security
element in the paper, the security element can additionally be designed with perfora-
tions, preferably in the edge area of the element.
[0032] In a preferred embodiment, the security element is designed in the form of a
security band which is intended for complete or partial embedding in a security paper
or value document.. The security band is designed in particular in the form of a rectan-
gular band with length L and width B, the tength L as a role corresponding to a typical
dimension of the security paper in which the security element is embedded. The inven-
tive solution shews special advantages if the security band is formed with a width, of
about 4 mm to about 20 mm,
[0033] In other, likewise advantageous embodiments, the security element is de-
signed in the form of a security stripe, a patch or another flat element. During produc-
tion of a security paper the flat element is preferably applied to the still moist paper
web, so that the fibers of the paper web can mesh with the fibers of the coating.

-7-
[0034] To further increase the falsification security, the security element can be
equipped with an optically variable effect, in particular a diffraction, pattern, a. holo-
gram, a color shift effect or other interference effects,
[0035] According to another preferred embodiment the security element is pro-
vided with a printed image or with positive or negative gaps in an opaque layer, e.g. a
metal layer, in the form of patterns or characters. The security element can also contain
fluorescent substances, phosphorescent substances or magnetic, substances as a farther
security feature. In all these embodiments, additional design options result compared
to conventional security threads due to the greater possible width of the security ele-
ment. For example, large-area print designs, such as flags, architectural motifs or por-
traits, can be used on a security band for the first time.
[0036] The invention also comprises a security paper for producing security or
value documents, such as bank notes, identity cards or the like, which is equipped with
an above-described security element, as well as a value document having such a secu-
rity element. The security element can be completely embedded in the security paper
or value document. Alternatively, the security element is embedded in the security pa-
per or value document in the manner of a windowed security thread and is visible in
window areas of the security paper or value document on the surface thereof. These-
curity clement can also form a pendulating security thread, which appears alternatingly
on opposite surfaces of the security paper or value document.
[0037] To make the security element inside the security paper or value document as
unobtrusive as possible in reflected light, the three-dimensional structuring of the secu-
rity element surface can be selected so that it bas substantially the same optical ap-
pearance as the paper substrate in which the security element is embedded, In particu-
lar, the fiber costing can have the same color as the paper substrate. If a fiber coating
with an optically divergent appearance is alternatively selected, the contrast between
security element and paper substrate can also be used deliberately as a design element.
[0038] In a method for producing a security paper of the described type, a paper
web is formed in a first method step, a security band with a substrate with, two oppo-
site main faces being embedded completely or partly in the paper during sheet forma-

-8-
tion. According to the invention, at least one surface of a main face of the substrate is
provided with a three-dimensional structure, in. particular a fiber coating, before em-
bedding,
[0039] According to preferred embodiments, the substrate of the security band is
flocked or coated with single fibers or laminated with a fiber coating in the form of a
textile fabric, in particular a woven, a knit, a felt or a noawoven. It is advantageous to
use here the synthetic fiber raw materials or natural fibers that are mentioned above,
[0040] For improved embedding of the security band in the security paper, the fiber
coating is preferably provided with an adhesive coating. The fiber coating can also be
provided with a hydrophilic coating, or the polarity of the fibers can be increased by a
corona or plasma pretreatment to improve the embedding.
[0041] Further embodiments as well as advantages of die invention will be ex-
plained hereinafter with reference to the figures. For more clarity, the figures do with-
out a representation that is true to scale and to proportion.
Fig, 1 shows a schematic representation of a bank note with a wide windowed se-
curity band according to one embodiment of the invention,
Fig. 2 shows the windowed security band of Fig. 1 in cross section along the line
II-II, and
Fig. 3 shows a security band according to another embodiment of the invention in
cross section.
[0042] The invention will be explained hereafter by the example of a bank note
Fig. 1 shows a schematic representation of a bank note 10 with an embedded wide
windowed security band 12 in a front view. The windowed security band 12 appears
on the surface of the bank note 10 at window areas 14, while it is embedded inside the
bank note 10 in the areas 16 there between.
[0043] The windowed security band 12 has a width of about 15 mm in this em-
bodiment. To permit such a wide security band to be embedded in the bank note 10

-9-
without thread streaks, the windowed security band 12 is provided with a fiber coating
on its underside. Fig. 2 shows schematically the structure of the windowed security
band 12, A fibrous mat 22, in the embodiment a cotton mat, with a weight per unit area
of about 15 g/m2 is applied to a PET substrate film 20. The fibrous mat 22 is firmly
connected to the substrate 20 via an adhesive layer of heat seal lacquer.
[0044] The windowed security band 12 is embedded, in the paper web in the way
known in the art during production of the security paper for the bank note 10. The fi-
brous mat 22 bereases the adhesion of the cellulose fibers to the surface of. the secu-
rity band. 12 and leads to closed sheet formation, despite the large width of the band,
via the considerably improved embedding of the security band 12 in the fiber bond of
the security paper. The security band 12 can be equipped with further security features
not shown in the figure, for example a hologram element or a print design.
[0045] Fig. 3 shows a security band 30 for complete embedding in a security paper
according to another embodiment of the invention. The security band 30 contains a
PET or OPP substrate film 32 which is provided with a fiber coating 34, 36 on each
side. In this embodiment the fiber coating is formed by a laminated knit of aramid fi-
bers on each side. Further adhesive layers 38 and 40 on the fiber coatings 34 and 36
serve to strengthen the anchorage of the wide security band 30 in a security paper.
[0046] The described security hand can be incorporated into a paper web not only
with a cylinder paper machine. With a fourdrinier paper machine the security band can
be supplied accordingly shortly before or shortly after the paper fiber layer leaves the
screen in the same way as with a cylinder paper machine.

-10-
Claims
1. A flat security element for a security paper, value document or the like having a
substrate (20; 32) with two opposite main faces, characterized in that at least one
main face of the substrate (20; 32) is provided with a three-djmensionally struc-
tured costing (22; 34,36).
2. The security element according to claim 1, characterized in that the three-
dimensionally structured coaling is a fiber coating, a foamed, embossed and/or
filled coating,.
3. The security element according to claim 1 or 2, characterized in that the fiber
coating is formed hy a textile fabric (22; 34,36), in particular a woven, a. knit, a.
felt, a nonwoven or a flocking with or a costing of single fibers.
4. The security element according to claim 2 or 3, characterized in that the fiber
coating (34, 36) comprises synthetic fiber raw materials which are in particular
selected from the group of viscose, aramid, PVAL, PET, PA and PP.
5. The security element according to at least one of claims 2 to 4, characterized in.
that the fiber coating (22) comprises natural fibers which are in particular se-
lected from the group of wool, silk, cotton, plant fibers, paper fibers and cellu-
lose.
6. The security element according ro at least one of claims 2 to 5, characterized in.
that the fiber coating comprises bicomponent fibers or multicomponent fibers, in
particular made of the fiber raw materials stated in claim 4 or 5.
7. The security element according to any of claims 2 to 6, charscterized in that the
fiber coating (22; 34, 36) comprises a fibrous mat with a weight per unit area of 8
to 30 g/m2 or less, preferably of .15 g/m2 or less.
8. The security element according to at least one of claims 2 to 7, characterized in
that the fiber coating comprises a woven with weft and warp threads made of dif-
ferent material.

-11-
9. The security element according to claim 8, characterized in that one of the mate-
rial threads is water-soluble.
10. The security element according to at least one of claims 2 to 9, characterized in
that the fiber coating comprises a fibrous mat or a fiber kail made of fibers with
different diameter and/or different titer.
11. The security element according to at least one of claims 2 to 10, characterized in
that the fiber coating (22; 34,36) is connected to the substrate via an adhesive
layer.
12. The security element according to at least one of claims 2 to 11, characterized in
that the fiber coating (34, 36) is provided with an adhesive coating (38, 40), in
particular a heat-activable adhesive or a hot-melt adhesive, for cmbedding or ap-
plying the security element in or to a security paper, value document or the like.
13. The security element according to at least one of claims 2 to 12, characterized in
that the fiber coaling (22- 34,36) is provided with, a hydrophilic coating.
14. The security element according to at least one of claims 2 to 13, characterized in
that the polarity of the fibers of the fiber coating (22; 34, 36) is increased by a co-
rona or plasma pretreatment.
15. The security element according to at least one of claims 1 to 14, characterized in
lhat only one main face of the substrate (20) is provided with a three-
dimensionally structured coating (22).
16. The security element according to at least one of claims 1 to 15, characterized in
that both main faces of the substrate (32) are provided with a three-dimensionally
structured coating (34, 36),
17. The security element according to at least one of claims 1 to 16, characterized in
that die main face or faces of the substrate (20; 32) are provided with the three-
dimensionally structured coaling (22; 34,36) all over.

-12-
18. The security element according to at least one of claims 1 to 17, characterized in
that the security element is designed in the form of a security baud (12; 30).
19. The security element seconding to claim 18, characterized in that the security
band (12; 30) has a width of about 4 mm to about 20 m
20. The security element according to at least one of claims 1 to 19, characterized in
that the security element is designed in the form of a security stripe, a patch or
another flat element.
21. The security element according to at least one of claims 1 to 20, characterized in
that the security element (12; 30) is equipped with an optically variable effect, in
particular a diffraction pattern, a hologram, a color shift effect or other interfer-
ence effects.
22. The security element according to at least one of claims 1 to 21 , characterized in
that the security element (12; 30) is provided with a printed image or with posi-
tive or negative gaps in an opaque layer in the form of characters or patterns.
23. The secvirity element according to at least one of claims 1 to 22, characterized in
that the security element (12; 30) contains fluorescent substances, phosphores-
cent substances or magnetic substances.
24. A security paper for producing security or value documents, such as bank notes,
identity cards or the like, having a security element (12; 30) according to at least
one of claims 1 to 23.
25. A value document; such as bank note, identity card or the like, having a security
element (12; 30) according to at least one of claims 1 to 23.
26. The security paper or value document according to claim 24 or 25, characterized
in that the security elament (30) is completely embedded in or applied to the se-
curity paper or value document.
27. The security paper or value document according to claim 24 or 25, characterized
in that the security element (12) is embedded in the security paper or value

-13-
document (10) and is visible in window areas (14) of the security paper or value
document (10) on the surface thereof.
28. The security paper or value document according to claim 26 or 27, characterized
in that the three-dimensionalty structured coating (22; 34, 36) of the security
element (12; 30) has substantially the same optical appearance as the paper sub-
strate in which the security element (12; 30) is embedded,
29. A method for producing a security paper according to at least one of claims 23 to
27 by which a paper web is formed in a first method step, a security element hav-
ing a substrate with two opposite main faces being embedded completely or
partly in the paper during sheet formation or applied to the paper after sheet for-
mation, characterized in that at least one main face of the substrate is provided
with a these-dimensionally structured coating before embedding or application,
30. The method according to claim 29, characterized in that the main face is pro-
vided with a fiber coating.
31. The method according to claim 30, characterized in that the substrate of the secu-
rity element is flocked of coated with single fibers.
32. The method according to claim 30 or 31, characterized in that the substrate of the
security element is laminated with a fiber coating in. the form of a textile fabric,
in particular a woven, a knit, a felt or a nonwoven.
33. The method according to at least one of claims 30 to 32, characterized in that the
fiber raw materials of the fiber coating comprise synthetic fibers, in particular se-
lected from the group of viscose, aramid, FVAL, PET, PA or PP, or comprise
natural fibers, in particular selected from the group of wool, silk, cotton, plant fi-
bers, paper fibers or cellulose,
34. The method according to at least one of claims 30 to 33, characterised in that the
fiber coating is provided with an adhesive coating for improved embedding of
the security element in the security paper or application to the security paper.

-14-
35. The method according to at least one of claims 30 to 34, characterized in that the
fiber coating is provided with a- hydrophilic coating.
36. The method according to at least one of claims 30 to 35, characterized in that the
polarity of the fibers of the fiber coating is increased by a corona or plasma pre-
treatment to improve the embedding.

The invention relates to a planar security element for a security paper valtrable dacumcnt or the like, comprising a substrate (20) with two opposite main surfaces. The aim of the invention is to improve the embedding of the security element (12) into a security paper or a va;lualble elements . For this purpose. at least main surface of the substrate (30) is pcovided with a spatially structured coating, e.g. a fiber coaling (22).
(57) Zusammeniussing: DieEifindung flachiges Sichertreselement flirein Sichertreselement . Wermdokument order der-gleichert miteinem Stbstral (20) mit zurd XXX Hanpfilachen. Erfindungsgenvifi ist zur Verbesserung der Enbeterng des Sichertreselement (12) in cin. cin Sichertreselement order ein Wendokument zumindest ripe Hamplflache ripe Hamplache des Substrsts(20)mit

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Patent Number

222728

Indian Patent Application Number

00776/KOLNP/2006

PG Journal Number

34/2008

Publication Date

22-Aug-2008

Grant Date

21-Aug-2008

Date of Filing

30-Mar-2006

Name of Patentee

GIESECKE & DEVRIENT GMBH

Applicant Address

PRINZREGENTENSTRASSE 159, 81677,MUNDHEN, GERMANY

Inventors:

#	Inventor's Name	Inventor's Address
1	MANG, THOMAS	RUHPOINTHOHE 7,83677 REICHERSBEUERN,GERMANY
2	BURCHARE, THEODOR	BUCHLETEN 1,83701 GMUND, GERMANY.

PCT International Classification Number

D21H21/40

PCT International Application Number

PCT/EP2004/009970

PCT International Filing date

2004-09-07

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	103 42 253.6	2003-09-11	Germany